AJR Am J Roentgenol

Doppler sonography of the superior mesenteric artery in Crohn''s disease.

Giovagnorio F. Diacinti D. Vernia P.
I Cattedra di Radiologia, Universita La Sapienza, Rome, Italy.
OBJECTIVE: The aim of this study was to evaluate blood flow in the superior mesenteric artery (SMA) in patients with active and inactive Crohn's disease (CD) using Doppler sonography to dynamically assess the changes of resistance in both fasting and postprandial states. SUBJECTS AND METHODS: Doppler sonography of the SMA was performed on 15 patients (mean age, 38 +/- 4 years) with active CD and on 15 patients (mean age, 41 +/- 5 years) with inactive CD. Imaging was performed at both fasting and 15 min after an 1890-kJ meal. A preliminary examination of 10 healthy volunteers with no signs of intestinal disease (mean age, 28 +/- 2 years) was necessary to define the parameters of normality. Because we wanted to express the postprandial resistive change in the SMA, we introduced a parameter called resistive difference (RD), defined as the mathematic difference between the resistive index measured at fasting (highest value) and measured at 15 min after the meal (lowest value). RESULTS: By evaluating the relationship between the RD and extension of disease, we found a direct correlation between progressive extension of disease and reduction of the RD in patients with active CD (correlation coefficient, .98) whereas we found no such correlation in patients with inactive CD (correlation coefficient, .05). CONCLUSION: We believe that Doppler sonography of the SMA is a promising noninvasive method to detect inflammatory disease of the small bowel, to evaluate its extension, and to document resolution of disease after therapy.

Single-shot MR cholangiopancreatography of neonates, infants, and young children.

Miyazaki T. Yamashita Y. Tang Y. Tsuchigame T. Takahashi M. Sera Y.
Department of Radiology, Kumamoto University School of Medicine, Japan.
OBJECTIVE: This study was undertaken to assess the usefulness of MR cholangiopancreatography (MRCP) with a half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequence as a noninvasive imaging technique to evaluate biliary or pancreatic disease in young children. SUBJECTS AND METHODS: We prospectively examined 45 children (mean age, 3 years) with MRCP using HASTE on a 1.5-T MR imaging unit. MRCP images were obtained in 1.4 sec without breath-hold. A body phased array coil and fat saturation technique were used for data collection. On the basis of the surgical (n = 19) and ERCP (n = 7) findings, clinical data, and follow-up observation, 21 children were deemed to have no significant abnormality. The other 24 children were found to have pancreaticobiliary disease, including congenital biliary atresia in five neonates, choledochal cyst in six infants, and anomalous connections between the bile and pancreatic ducts in four infants and nine young children. In children without abnormality, the MRCP images were graded for the depiction of normal structures. The findings obtained by MRCP were correlated with the surgical or ERCP results. RESULTS: HASTE MRCP showed the first branch of the intrahepatic duct, the common hepatic duct, the gallbladder, and the common bile duct in most children. In the 21 children with no abnormalities, the main pancreatic duct was visible in two of six neonates, in four of five infants, and in all 10 young children. The diagnostic accuracy of MRCP was 100% in patients with choledochal cysts, 100% in those with congenital biliary atresia, and 69% in those with anomalous connections between the bile and pancreatic ducts. CONCLUSION: MRCP using HASTE with a phased array coil is a noninvasive technique for revealing the pancreaticobiliary tract in young children.

Assessment of aortic invasion by esophageal carcinoma using intraaortic endovascular sonography.

Koda Y. Nakamura K. Kaminou T. Osugi H. Nakata M. Hamuro M. Hayashi S. Takashima S. Higashino M. Yamada R.
Department of Radiology, Osaka City University Medical School, Japan.
OBJECTIVE: Accurate preoperative assessment of aortic invasion by esophageal carcinoma is of great importance for planning surgery. We compared the accuracy of intraaortic endovascular sonography with that of CT in the diagnosis of aortic invasion by esophageal carcinoma. CONCLUSION: In this study, intraaortic endovascular sonography was sensitive in detecting aortic invasion; both sensitivity and specificity were 100%. Intraaortic endovascular sonography proved useful in detecting aortic invasion by esophageal carcinoma.

Imaging of the liver with helical CT: a survey of scanning techniques.

Silverman PM. Kohan L. Ducic I. Javadi S. Meyer C. Sharma N. Cooper C. Zeman RK.
Department of Radiology, Georgetown University Hospital, Washington, DC 20007, USA.
OBJECTIVE: We conducted a survey of the members of the Society of Computed Body Tomography/Magnetic Resonance to assess current techniques in liver imaging using helical CT. MATERIALS AND METHODS: The survey, which was designed to update earlier surveys from 1987 and 1993, included a questionnaire distributed to 77 members of the Society of Computed Body Tomography/Magnetic Resonance. RESULTS: Forty-nine members responded, representing 28 institutions. In 1993, 19% (5/26) of institutions used helical scanners, compared with 82% (23/28) in 1996. The group of institutions with helical CT served as the focus of this survey. In 1993, 58% of institutions used 1-cm collimation: in 1996, 78% (18/23) used thinner, 7- to 8-mm collimation. In 1987, 41% used power injectors compared with 85% in 1993 and 100% in 1996. In 1996, monophasic injections were used by 96% (22/23) of institutions. In 1993, most institutions used a contrast material injection rate of 1.5-2.0 ml/sec; in 1996, most used a 2.5-3.0 ml/sec injection rate. In 1993, 96% of institutions used 125-150 ml of contrast material; in 1996, 57% (13/23) of institutions used 125-150 ml and 30% of institutions used less than 125 ml of contrast material. A delay time of 21-45 see was used by 83% of institutions in 1993, whereas in 1996, 83% (19/23) of institutions used a longer delay time of 50-80 sec. In 1996, 13% of institutions used an individual scan delay technology and all institutions performed multiphasic scanning of hypervascular lesions. CONCLUSION: The availability of helical CT has changed radiologists' approach to liver imaging. The greatest effects of which are a more widespread use of power injectors, longer delay times, thinner collimation, increased contrast material injection rates, decreased contrast material volumes, and multiphasic scanning.

Evaluation of portal pressure by splenic perfusion measurement using dynamic CT.

Tsushima Y. Koizumi J. Yokoyama H. Takeda A. Kusano S.
Department of Radiology, National Defense Medical College, Saitama, Japan.
OBJECTIVE: The purposes of this study were to determine if splenic perfusion measurements obtained using dynamic CT are useful in the evaluation of portal hypertension. MATERIALS AND METHODS: Forty-four patients with chronic liver disease (29 men and 15 women, 49-81 years old) and 38 control subjects (17 men and 21 women, 21-79 years old) underwent dynamic CT of the spleen. Regions of interest were drawn on images of the spleen and aorta, and splenic perfusion was calculated by dividing the peak gradient of the splenic time-attenuation curve by the peak aortic CT measurement increase. In 11 patients with chronic liver disease and three patients with normal livers, we measured the wedged hepatic vein pressure (WHVP) of the right or right accessory hepatic vein to estimate portal vein pressure. RESULTS: Splenic perfusion was less in patients with chronic liver disease (0.894 +/- 0.324 ml/min) than in the control group (1.299 +/- 0.429 ml/min; p < .0001). We found a significant negative correlation between splenic perfusion and WHVP (r = .741; p = .0024). CONCLUSION: A significant decrease in splenic perfusion in patients with chronic liver disease negatively correlated with WHVP. Measurement of splenic perfusion may be useful in the evaluation of portal hypertension.

Differential diagnosis of small hepatocellular carcinoma and adenomatous hyperplasia with power Doppler sonography.

Koito K. Namieno T. Morita K.
Department of Radiology, Sapporo Medical University, Japan.
OBJECTIVE: The aim of this study was to compare the ability of power Doppler sonography and color Doppler sonography to differentiate hepatocellular carcinoma (HCC) from adenomatous hyperplasia (AH). SUBJECTS AND METHODS: In 48 patients with cirrhosis of the liver, color Doppler sonography and power Doppler sonography were performed on 53 hepatic nodules smaller than 20 mm in diameter (32 nodules were HCC; 21 nodules were AH). We evaluated the detectability of the pulsatile and continuous flows in the nodules at each hepatic segment. RESULTS: Thirty-four percent of nodules produced color signal on color Doppler sonography; 77%, on power Doppler sonography (p < .01). The identification rate of nodules in the left lateral segment was significantly lower than in other segments. Continuous flow was seen in the nodules of both HCC and AH. However, only in HCC did we see pulsatile flow. For HCC, pulsatile flow was seen with color Doppler sonography in 25% of the nodules smaller than 10 mm in diameter and in 50% of the nodules between 10 and 20 mm. With power Doppler sonography, pulsatile flow was seen in 67% (p < .05) of the nodules smaller than 10 mm and in 90% (p < .01) of the nodules between 10 and 20 mm. Sensitivity and negative predictive value in the differentiation of HCC from AH were significantly higher with power Doppler sonography than with color Doppler sonography (81% versus 41%, respectively, for sensitivity and 78% versus 53%, respectively, for negative predictive value). Specificity, positive predictive value, and efficacy of both color Doppler sonography and power Doppler sonography were 100%, 100%, 60%, respectively. CONCLUSION: On the basis of our results, power Doppler sonography is more sensitive than color Doppler sonography in revealing small HCC and in differentiating HCC from AH under physiologic hemodynamic conditions.

MR cholangiography in neonates and infants: feasibility and preliminary applications.

Guibaud L. Lachaud A. Touraine R. Guibal AL. Pelizzari M. Basset T. Pracros JP.
Pediatric Imaging Department, Hopital Debrousse, Universite Lyon-Sud, France.
OBJECTIVE: The objective of the study was to evaluate the accuracy of MR cholangiography in showing the biliary tree in neonates and infants and to show preliminary applications in a pediatric population. SUBJECTS AND METHODS: MR cholangiography was performed with T2-weighted turbo spin-echo sequences (8000/300 [TR/TE], six or eight excitations). The study included seven patients with suspected bile duct disorders and 10 control individuals. RESULTS: In the control group, the extrahepatic bile ducts (EHBDs) were revealed by MR cholangiography in all patients. In one of the five patients with neonatal cholestasis, biliary atresia was excluded by identifying the entire EHBD on MR cholangiograms. In the four other patients with neonatal cholestasis, biliary atresia was suspected because the EHBD could not be seen on MR cholangiography. The diagnosis was confirmed in three of these four patients, in whom the MR finding was associated with significant periportal thickening. In the remaining patient, in whom periportal thickening was not seen, sclerosing cholangitis was diagnosed on biopsy. In the sixth patient with neonatal cholestasis, who had received a liver transplant, MR cholangiography showed biliary dilatation above the biliary-digestive anastomosis. In the seventh patient, a neonate with a prenatal diagnosis of hepatic cyst, MR cholangiography showed a choledochal cyst. CONCLUSION: MR cholangiography may become an important diagnostic tool in the detection of biliary atresia, congenital choledochal dilatation, and biliary complications in hepatic transplantation for pediatric patients.

Two-phase study of hepatic artery vascular occlusion with microencapsulated cisplatin in patients with liver metastases from neuroendocrine tumors.

Diamandidou E. Ajani JA. Yang DJ. Chuang VP. Brown CA. Carrasco HC. Lawrence DD. Wallace S.
Department of Gastroenterology Medical Oncology, University of Texas M. D. Anderson Cancer Center, Houston 77030, USA.
OBJECTIVE: We conducted a two-phase trial in which 100-micron polylactic acid microcapsules with a cisplatin payload (manufactured at our institution [the M. D. Anderson Cancer Center]) were used for hepatic artery occlusion therapy for symptomatic patients who had liver metastases from neuroendocrine tumors. SUBJECTS AND METHODS: Between January 1993 and December 1995, 20 patients with advanced, unresectable, symptomatic neuroendocrine tumors with liver metastases received repeated hepatic artery occlusion therapy using encapsulated cisplatin. The dose of encapsulated cisplatin was increased in a stepwise fashion. Selective angiography was used to occlude the portion of the hepatic vasculature that had the most metastases with encapsulated cisplatin microcapsules. In each patient, hepatic artery occlusion therapy was repeated in 6-8 weeks and responses were evaluated. Subsequent vascular occlusions were performed on the basis of the level of palliation achieved and the persistence of symptoms. RESULTS: Of the 20 patients, 17 patients had carcinoid tumors and three had islet cell tumors. The median percentage of liver replacement was approximately 50%. Fifteen of the 20 patients had received prior therapy and 17 patients had hormonal syndrome at the beginning of therapy. One patient had tumor bulk-related symptoms. Nineteen patients had elevated peptides markers that could be followed serially Six patients received encapsulated cisplatin at 50 mg/m2, four patients at 75 mg/m2, and 10 patients at 100 mg/m2 of body surface area. The median number of vascular occlusive procedures per patient was three. All patients were assessable for toxicity and 18 were assessable for response (the other two patients were not assessable because of loss of follow-up). The median follow-up time was 14 months. Twelve (67%) of 18 patients had a median reduction in symptoms of 50%. Eleven (73%) of 15 patients with elevated 24-hr-urine levels of 5-hydroxyindoleacetic acid had a median reduction of 64% for this symptom. We observed objective reduction in the tumors of 14 of the 18 patients. In six of the 14 patients, we noted a partial response. In eight, we observed a minor response. In four of the 18 patients, we noted no response. One treatment-related death resulted from hepatorenal syndrome. Other major complications included hepatic pain (100%), fever (100%), nausea (100%), and vomiting (95%). Also all patients had a transient elevation of liver enzymes. Five of the 20 patients died of disease during our study. CONCLUSION: Hepatic artery vascular occlusion therapy using encapsulated cisplatin is feasible, can palliate symptoms, and can produce biochemical and objective responses in liver metastases from neuroendocrine tumors. The maximum tolerated dose appears to be 100 mg/m2 of body surface area per treatment. Polylactic acid capsules have potential because they can incorporate multiple agents. With surface coating, such capsules can also be used to target specific receptors.

Helical CT of the pancreas: a comparison of cine display and film-based viewing.

Bonaldi VM. Bret PM. Atri M. Reinhold C.
Department of Radiology, Montreal General Hospital, McGill University, Quebec, Canada.
OBJECTIVE: Radiologists must manage a tremendous number of helical CT images daily. Hence, the use of cine display review is increasing. Our aim was to compare cine display of helical CT examinations of the pancreas with conventional film-based viewing. SUBJECTS AND METHODS: Forty-eight consecutive patients undergoing helical CT of the pancreas were prospectively included in the study. Five-millimeter-thick contrast-enhanced helical CT sections of the pancreas were reconstructed in 1-mm increments for cine display review and in 5-mm-thick increments for film-based review. Two radiologists reviewed the two sets of data independently. Review of the cine display images was followed by review of the film-based images 2 months later. For both the cine display and the film-based images, reviewers used a four-point scale to grade vascular anatomy (splenic vein and artery, superior mesenteric vein and artery, portal confluence, dorsal pancreatic artery, and gastroduodenal artery); ductal anatomy (common bile duct in its hilar, suprapancreatic, and intrapancreatic portions and pancreatic duct in its caudal, corporeal, and cephalic portions); sharpness of the pancreatic and lesion contours; and overall image quality. RESULTS: The conspicuity of pancreatic contours was graded better on cine display (p = .0035). All venous and arterial landmarks were graded significantly better on cine display. Likewise, visibility of the common bile ducts and pancreatic ducts was scored significantly better with cine display. In three patients, cine display images revealed the pancreatic duct, and the film-based images did not. Although 21 lesions were shown on both sets of images, the lesions were better seen on cine display (p < .005). CONCLUSION: Vascular and ductal anatomy is better delineated on cine images generated from overlapped sections than on conventional film-based images. Lesions are also more sharply delineated on cine display images.

Small peripancreatic veins: improved assessment in pancreatic cancer patients using thin-section pancreatic phase helical CT.

Vedantham S. Lu DS. Reber HA. Kadell B.
Department of Radiological Sciences, University of California, Los Angeles 90095-1721, USA.
OBJECTIVE: Recent studies have shown evaluation of the small peripancreatic veins to have potential in improving pancreatic cancer staging. This study was performed to determine the effectiveness of thin-section pancreatic phase helical CT images in visualizing these veins. MATERIALS AND METHODS: Seventy-two patients (30 with pancreatic adenocarcinoma and 42 with no pancreatic disease) underwent dual-phase helical CT with thin-section pancreatic phase acquisition (40-70 sec after i.v. contrast initiation at 3 ml/sec) and hepatic phase acquisition (70-100 sec). Visualization (with diameter measurement) or nonvisualization of the posterior superior pancreaticoduodenal vein (PSPDV), anterior superior pancreaticoduodenal vein (ASPDV), and gastrocolic trunk was recorded for both acquisitions. We also correlated surgical tumor resectability with the status of the small peripancreatic veins. RESULTS: Visualization of peripancreatic veins was significantly better on pancreatic phase images than on hepatic phase images for both healthy individuals (PSPDV, 88% of the veins visualized on the pancreatic phase images versus 50% on the hepatic phase images; ASPDV, 93% on the pancreatic phase images versus 48% on the hepatic phase images; gastrocolic trunk, 98% on the pancreatic phase images versus 76% on the hepatic phase images) and for pancreatic cancer patients (PSPDV, 97% on the pancreatic phase images versus 57% on the hepatic phase images; ASPDV, 77% on the pancreatic phase images versus 43% on the hepatic phase images) (p < .05). The exception was the gastrocolic trunk in cancer patients (83% on the pancreatic phase images versus 77% on the hepatic phase images) (p > .05). In pancreatic cancer patients, 11 dilated peripancreatic veins were identified on the pancreatic phase images compared with six on the hepatic phase images. However, only one of the 11 dilated peripancreatic veins was in a patient with surgically resectable disease. CONCLUSION: In a dual-phase helical CT protocol, thin-section pancreatic phase images provided visualization of the small peripancreatic veins that was superior to hepatic phase images, providing further support for the use of this protocol in pancreatic cancer evaluation.

Diffusion-weighted MR imaging with a single-shot echoplanar sequence: detection and characterization of focal hepatic lesions.

Ichikawa T. Haradome H. Hachiya J. Nitatori T. Araki T.
Department of Radiology, Yamanashi Medical University, Japan.
OBJECTIVE: The purpose of this study was to determine the usefulness of diffusion-weighted MR imaging with single-shot echoplanar imaging in characterizing focal hepatic lesions by apparent diffusion coefficient (ADC) and contrast-to-noise ratio (CNR) measurements. MATERIALS AND METHODS: Diffusion-weighted imaging on a 1.5-T MR unit was performed in 46 patients with 74 known focal hepatic lesions (11 hemangiomas, 15 metastases, and 48 hepatocellular carcinomas [HCCs]). Mean values for ADCs and CNRs of all lesions were calculated. Mean values for CNRs with diffusion-weighted imaging were also compared with those for breath-hold T2-weighted fast spin-echo images. RESULTS: The mean values for ADCs were different for each type of tumor (5.39 x 10(-3) mm2/sec +/- 1.23 in hemangiomas, 2.85 x 10(-3) mm2/sec +/- 0.59 in metastases, and 3.84 x 10(-3) mm2/sec +/- 0.92 in HCCs), and each of them was significantly greater than the mean values for ADCs of the normal liver (2.28 x 10(-3) mm2/sec +/- 1.23 in normal liver [p < .05] except metastasis versus normal liver [p < .1]). Also, the mean values for ADCs were based on differences of ADC values. Only four (6%) of 63 malignant tumors (three HCCs and one metastasis) could not be differentiated from hemangiomas. The mean value for CNRs with diffusion-weighted images (14.4 +/- 8.54 in HCC and 29.0 +/- 6.79 in metastasis) was significantly higher than the mean values for CNRs obtained with T2-weighted fast spin-echo images in both metastases and HCCs (p < .05), whereas no significant difference was seen for hemangiomas. CONCLUSION: Mean values for ADCs differed for the three types of the hepatic lesions and were higher than ADCs of the normal liver. We suggest that diffusion-weighted imaging may be useful for increased detection of HCCs and metastases and in distinguishing these entities from hemangiomas.

Treatment of malignant biliary obstruction with polyurethane-covered Wallstents.

Hausegger KA. Thurnher S. Bodendorfer G. Zollikofer CL. Uggowitzer M. Kugler C. Lammer J.
Department of Radiology, University Hospital Graz, Austria.
OBJECTIVE: This study was undertaken to determine the safety, efficacy, and performance of polyurethane-covered Wallstents in the treatment of malignant biliary obstruction. SUBJECTS AND METHODS: This pilot study included 30 patients with malignant biliary obstruction. Palliative decompression of the obstructed bile duct was attempted with a polyurethane-covered Wallstent that is a prototype. Patients with hilar obstructions were excluded. All stents were inserted percutaneously. Kaplan-Meier analysis was used to determine stent patency. RESULTS: Effective biliary decompression was achieved in all patients initially. No acute stent-related complications occurred. The 30-day mortality rate was 20%. During follow-up, 11 stent occlusions occurred; therefore, the occlusion rate was 37%. The patency rates after 1, 3, 6, and 12 months were 96%, 69%, 47%, and 31%, respectively. Tumor growth through the stent covering that was proven both histologically and by biopsy observed in two patients, causing stent occlusion in one of them. Other reasons for stent occlusion were distal tumor ingrowth (n = 1) and biopsy-proven granulation tissue inside the stent (n = 2). Otherwise, the reasons for stent occlusion remained unclear. CONCLUSION: This prototype of a covered stent did not provide better results than did conventional uncovered stents in patients with malignant biliary obstruction. The covering did not effectively prevent tumor ingrowth in at least two patients. The stent also seems prone to premature occlusion.

Congenital hepatic fibrosis: findings at MR cholangiopancreatography.

Ernst O. Gottrand F. Calvo M. Michaud L. Sergent G. Mizrahi D. L'Hermine C.
Department of Radiology, Radiologie Est, Centre Hospitalier Universitaire de Lille, France.
OBJECTIVE: This study describes the MR imaging features of congenital hepatic fibrosis in four children who were examined with MR cholangiopancreatography. CONCLUSION: MR cholangiopancreatography effectively reveals biliary cysts, dilatation of intrahepatic bile ducts, and polycystic kidney disease, findings often associated with congenital hepatic fibrosis. This diagnosis should be suspected when these biliary and renal abnormalities are associated with hepatosplenomegaly in a patient with normal liver function.

Recognition of intussusception around gastrojejunostomy tubes in children.

Connolly BL. Chait PG. Siva-Nandan R. Duncan D. Peer M.
Department of Diagnostic Imaging, University of Toronto, Hospital for Sick Children, Ontario, Canada.
OBJECTIVE: We describe antegrade intussusceptions of duodenum and jejunum around gastrojejunostomy tubes seen on sonography and fluoroscopic contrast tube studies. Reduction of the intussusception was achieved by bolus injection of air or contrast medium through the tube or exchange over a wire. CONCLUSION: Sonography and fluoroscopic contrast tube studies permit diagnosis of intussusception around gastrojejunostomy tubes.

Nonalcoholic duct-destructive chronic pancreatitis: imaging findings.

Year 1998
Van Hoe L. Gryspeerdt S. Ectors N. Van Steenbergen W. Aerts R. Baert AL. Marchal G.
Department of Radiology, University Hospitals Katholieke Universiteit Leuven, Belgium.
OBJECTIVE: Nonalcoholic duct-destructive chronic pancreatitis is a new entity that should be distinguished from alcoholic chronic pancreatitis. The purpose of this study was to assess the imaging features of nonalcoholic duct-destructive chronic pancreatitis. CONCLUSION: Nonalcoholic duct-destructive chronic pancreatitis has characteristic CT and MR imaging features that include the presence of a focal or more diffuse mass causing either regular or irregular narrowing of the main pancreatic duct, the absence of parenchymal atrophy and significant ductal dilatation proximal to the site of stenosis, and the absence of extrapancreatic spread.

Pancreatic enhancement and pulse sequence analysis using low-dose mangafodipir trisodium.

Year 1998
Mayo-Smith WW. Schima W. Saini S. Slater GJ. McFarland EG.
Department of Radiology, Massachusetts General Hospital, Boston, MA, USA.
OBJECTIVE: The purpose of this study was to evaluate pancreatic enhancement with low-dose mangafodipir trisodium (5 mumol/kg) using three different T1-weighted pulse sequences. SUBJECTS AND METHODS: Fifteen patients, six of whom had proven focal pancreatic tumors, underwent T1-weighted gradient-recalled echo imaging, spin-echo imaging, and fat-suppressed spin-echo imaging before and 30 min after injection of 5 mumol/kg of mangafodipir trisodium. Region-of-interest measurements were obtained in the pancreas before and after contrast enhancement. Signal-to-noise ratios were calculated in all 15 patients. Contrast-to-noise ratios were calculated in the six patients with pancreatic tumors. RESULTS: The signal-to-noise ratios of the pancreas increased after injection of mangafodipir trisodium on all three T1-weighted pulse sequences (p < .001). Enhanced fat-suppressed sequences (29 +/- 7.7) and gradient-recalled echo sequences (29 +/- 9.6) had the highest signal-to-noise ratios. Contrast-to-noise ratios between normal pancreatic tissue and pancreatic tumor also increased after contrast administration (p < .05) and were highest on the fat-suppressed (-9.6 +/- 4.0) pulse sequence. CONCLUSION: Mangafodipir trisodium produced marked pancreatic enhancement at a dose of 5 mumol/kg for all three T1-weighted pulse sequences. The enhanced T1-weighted spin-echo fat-suppressed sequence showed the highest signal-to-noise and contrast-to-noise ratios.

Benign obstruction of the hepatic inferior vena cava complicated by hepatocellular carcinoma: combined interventional management.

Year 1998
Seo JB. Chung JW. Park JH. Kim SH. Kim TK. Han JK. Choi BI. Han MC.
Department of Radiology, Seoul National University College of Medicine, South Korea.
OBJECTIVE: The risk of hepatocellular carcinoma is increased with benign obstruction of the hepatic inferior vena cava (IVC). The purpose of this study was to assess the usefulness of combined interventional treatment for benign obstruction of the hepatic IVC associated with hepatocellular carcinoma. MATERIALS AND METHODS: In a retrospective review of 51 patients with benign obstruction of the hepatic IVC, hepatocellular carcinoma was detected in 15 patients coincidentally or during the follow-up period. Obstruction of the IVC was treated with percutaneous transluminal balloon angioplasty in five patients and metallic stent placement in two patients. Immediate postprocedural and follow-up venacavography was performed to evaluate the effectiveness of this interventional management. Hepatocellular carcinomas were managed with transcatheter chemoembolization in all 15 patients using an emulsion of 3-12 ml of an iodized oil and 20-50 mg of doxorubicin hydrochloride. Gelfoam embolization was performed in three patients. Transcatheter chemoembolizations were repeated in seven patients. Initial response and long-term response to treatment were evaluated by monitoring the level of serum alpha-fetoprotein and by follow-up CT and angiography. RESULTS: During the follow-up period (1-8 years), the IVC was widely open except in one patient who developed moderate stenosis. Clinical symptoms of vena caval obstruction disappeared in all patients. After initial transcatheter chemoembolization, complete remission of the tumor occurred in six patients and partial remission occurred in seven patients. Five of the seven patients who underwent further chemoembolizations remained unchanged or in remission. CONCLUSION: Radiologic interventional treatment plays a significant role in managing both kinds of lesions in patients with benign obstruction of the hepatic IVC complicated by, hepatocellular carcinoma. A follow-up regimen should be designed to detect small hepatocellular carcinoma as early as possible after obstruction of the hepatic IVC is diagnosed.

MR cholangiography in children after liver transplantation from living related donors.

Year 1998
Laor T. Hoffer FA. Vacanti JP. Jonas MM.
Department of Radiology, Children's Hospital, Boston, MA 02115, USA.
OBJECTIVE: The purpose of this study is to report our technique for MR cholangiography in children and to describe the postoperative imaging findings in children who have undergone liver transplantation from living related donors. CONCLUSION: MR cholangiography can be used to delineate anatomy and morphology of the bile ducts of the left lateral segment graft in children who have undergone liver transplantation from living related donors. This information can guide treatment of postoperative biliary complications with interventional radiology or surgery.

Percutaneous CT-guided catheter drainage of infected acute necrotizing pancreatitis: techniques and results.

Year 1998
Freeny PC. Hauptmann E. Althaus SJ. Traverso LW. Sinanan M.
Department of Radiology, University of Washington School of Medicine, Seattle 98195, USA.
OBJECTIVE: The objective of this paper was to assess the safety and efficacy of percutaneous catheter drainage for initial treatment of infected acute necrotizing pancreatitis. MATERIALS AND METHODS: Thirty-four patients with acute necrotizing pancreatitis shown with contrast-enhanced CT were treated for sepsis with percutaneous catheter drainage. Extent of necrosis was less than 30% in 10 cases, 30-50% in 10 cases, and greater than 50% in 14 cases. Fourteen patients had central necrosis. Eighteen patients were critically ill with multiorgan failure. RESULTS: Sixteen (47%) of the 34 patients were cured with only percutaneous catheter drainage, including four (29%) of the 14 patients with central gland necrosis and 12 (60%) of the 20 with body-tail necrosis. Sepsis was controlled (defervescence of fever and return of WBC to normal) in an additional nine patients, allowing elective pancreatic surgery for control of pancreatic duct fistula. Eight patients failed to show clinical improvement after drainage and required necrosectomy. No patient experienced catheter-related complications. Mortality was 12% (all four deaths occurred after necrosectomy because of multiorgan failure). CONCLUSION: Percutaneous catheter drainage is a safe and effective technique for treating infected acute necrotizing pancreatitis. Overall, sepsis was controlled in 74% of patients, permitting elective surgery for treatment of pancreatic fistula, and 47% of patients were cured with no surgery required. No catheter-related complications occurred.

Percutaneous drainage of pancreatic necrosis: is it ecstasy or agony?

Year 1998
Mueller PR.
Department of Radiology, Massachusetts General Hospital, Boston 02114, USA.
The above comments are meant to help the reader further analyze the fine study of Freeny et al. [1]. To my knowledge, this is the first series to specifically define its patients correctly as having pure pancreatic necrosis. This work represents a thorough analysis of a difficult problem and points out how to treat these patients if one wants to be successful. This template is important to radiologists who wish to get involved with this type of patient. What Freeny et al. truly describe is the agony and ecstasy involved with this difficult undertaking. Radiologists can obtain a lot of satisfaction in taking care of this type of patient, but they and the referring physicians must be committed. The patient, the referring physician, and the radiologist must also face the agony in dealing with the illness. They must be ready to handle the number of catheters, the number of catheter changes, the number of CT scans, and the duration of drainage. In some cases percutaneous drainage will work; in some cases it is the only alternative for a patient with this disease. In other cases a catheter or two can be placed, but they might not be as beneficial to the patient as surgery. Clearly, percutaneous drainage of pancreatic necrosis can be done, and radiologists must work with their clinical colleagues to decide whether it is in the patient's best interest.

Patterns of neoplastic spread in colorectal cancer: implications for surveillance CT studies.

Year 1998
Giess CS. Schwartz LH. Bach AM. Gollub MJ. Panicek DM.
Department of Radiology, Memorial Sloan-Kettering Cancer Center, Cornell University Medical College, New York, NY 10021, USA.
OBJECTIVE: This study was performed to assess patterns of metastatic disease shown on CT in colorectal cancer and to determine the diagnostic yield of routine pelvic CT in follow-up surveillance. MATERIALS AND METHODS: Pathology records and 3073 CT studies of 1119 patients with colorectal cancer were retrospectively reviewed. Primary tumor site, site of abdominal or pelvic metastases (liver, peritoneum, lymph nodes, local recurrence, or other), and incidental nonmetastatic pelvic disease were recorded. The superior iliac crests were considered the border between the abdomen (above) and the pelvis (below). RESULTS: Metastatic disease was present in 34% (1040/3073) of all CT studies: 33% (1007/3073) in the abdomen and 7% (227/3073) in the pelvis. Six percent (194/3073) of studies had metastases in both abdomen and pelvis. Forty-one percent (404/991) of studies showing abdominal primary colonic tumors showed metastatic disease: 40% (400/991) in the abdomen and 8% (78/991) in the pelvis. Four studies (0.4%; 4/991) in four different patients with abdominal primary colon tumors had isolated pelvic metastases; three of these were primary tumors of the cecum. Thirty-one percent (636/2082) of studies showing pelvic primary colonic tumors showed metastatic disease: 29% (607/2082) in the abdomen and 7% (149/2082) in the pelvis. Twenty-nine studies (1%; 29/2082) in 26 patients with pelvic primary colonic tumors revealed isolated pelvic metastases. CONCLUSION: In colorectal tumors arising within the abdomen, pelvic metastases are uncommon and isolated pelvic metastases are rare. Routine pelvic CT performed in the follow-up surveillance of patients with colorectal cancer with primary tumors arising in the abdominal portion of the colon has a low diagnostic yield.

Hepatocellular carcinoma in North America: a multiinstitutional study of appearance on T1-weighted, T2-weighted, and serial gadolinium-enhanced gradient-echo images.

Year 1998
Kelekis NL. Semelka RC. Worawattanakul S. de Lange EE. Ascher SM. Ahn IO. Reinhold C. Remer EM. Brown JJ. Bis KG. Woosley JT. Mitchell DG.
Department of Radiology, University of North Carolina, Chapel Hill 27599-7510, USA.
OBJECTIVE: The purpose of this study was to define the common appearances of hepatocellular carcinoma (HCC) in patients in North America by analyzing T1-weighted, T2-weighted, and serial gadolinium-enhanced gradient-echo images interpreted by radiologists at multiple institutions in North America. MATERIALS AND METHODS: One hundred thirteen consecutive patients with HCC from eight institutions were included in this retrospective case series. Inclusion criteria included MR imaging examinations performed on 1.5-T MR imagers using T1-weighted breath-hold spoiled gradient-echo images, T2-weighted images, and serial gadolinium-enhanced spoiled gradient-echo images. Diagnosis was established by histology in all patients. Images were analyzed retrospectively for lesion count, lesion diameter as less than or equal to 1.5 cm and greater than 1.5 cm, and signal intensity, by individual experienced radiologists at each institution. RESULTS: We found 354 HCC lesions in the 113 patients. Tumors were solitary in 63 patients, multifocal in 45 patients, and diffuse in five patients. Lesion appearance on combined T1-weighted, T2-weighted, and immediate gadolinium-enhanced spoiled gradient-echo images was as follows: 102 lesions (29%) were hypointense on T1-weighted images, were hyperintense on T2-weighted images, and exhibited diffuse heterogeneous enhancement; 52 lesions (15%) were isointense on both T1- and T2-weighted images and exhibited diffuse homogeneous enhancement (all of these lesions measured < or = 1.5 cm in diameter); 50 lesions (14%) were hypointense on T1-weighted images, were hyperintense on T2-weighted images, and exhibited diffuse homogeneous enhancement; 33 lesions (9%) were hypointense on T1-weighted images, were hyperintense on T2-weighted images, and exhibited predominantly peripheral rim enhancement; and 27 lesions (8%) were hypointense on T1-weighted images, were isointense on T2-weighted images, and exhibited diffuse homogeneous enhancement. The remaining 90 lesions showed less common patterns. The appearance of HCCs greater than 1.5 cm and of HCCs less than or equal to 1.5 cm was significantly different (p = .001). The appearance of histologically proven HCCs is separately described. CONCLUSION: The combination of hypointensity on T1-weighted images, hyperintensity on T2-weighted images, and diffuse heterogeneous enhancement was the most common appearance of HCC on MR images in a multiinstitutional patient population in North America. Small HCCs measuring less than or equal to 1.5 cm were frequently isointense on both T1-weighted and T2-weighted images and may be detected on immediate gadolinium-enhanced images only as diffuse homogeneously enhancing lesions.

Percutaneous treatment of small hepatic tumors by an expandable RF needle electrode.

Year 1998
Rossi S. Buscarini E. Garbagnati F. Di Stasi M. Quaretti P. Rago M. Zangrandi A. Andreola S. Silverman D. Buscarini L.
Department of Gastroenterology, Hospital of Piacenza, Italy.
OBJECTIVE: The aim of this study was to evaluate the usefulness of expandable RF needle electrodes in the treatment of hepatic cancer. SUBJECTS AND METHODS: Thirty-seven patients, 23 of whom had 26 hepatocellular carcinoma nodules and 14 of whom had 19 hepatic metastatic nodules, underwent treatment by RF interstitial thermal ablation with expandable needle electrodes. Forty-five tumor nodules were treated in 64 RF interstitial thermal ablation sessions with 83 needle electrode insertions. The mean diameter of the tumor nodules was 2.5 cm (range, 1.1-3.5 cm). Immediate posttreatment tumor necrosis was evaluated by dynamic CT in all cases. Two patients with hepatocellular carcinoma and three patients with metastases underwent surgical resection 20-60 days after RF treatment. The remaining 32 patients were followed up clinically. RESULTS: The mean number of RF interstitial thermal ablation sessions to complete tumor nodule treatment was 1.4. Mean number of needle electrode insertions was 1.8. No complications were observed. Posttreatment dynamic CT showed a completely nonenhancing area in the site of the treated tumor in 44 of 45 cases. The remaining patient with metastatic disease had persistent enhancing tissue. Histology showed complete necrosis in four treated tumor nodules and residual viable cancer in one. Twenty-one patients with hepatocellular carcinoma were followed up for 6-19 months (mean, 10 months). Of these patients, six showed recurrences and 15 remained apparently disease-free. Two patients died, one from advanced cancer and one from other causes. Eleven patients with hepatic metastases were followed up for 7-20 months (mean, 12 months). Of these patients, nine showed recurrent disease and only two remained apparently disease-free. Two patients died from disseminated disease. CONCLUSION: RF interstitial thermal ablation of hepatic tumor by expandable needle electrodes is a safe and effective technique. Local ablation of tumors not exceeding 3.5 cm in diameter is achieved in a short time without complications.

Characterization of hepatic lesions by perfusion-weighted MR imaging with an echoplanar sequence.

Year 1998
Ichikawa T. Haradome H. Hachiya J. Nitatori T. Araki T.
Department of Radiology, Yamanashi Medical University, Japan.
OBJECTIVE: The purpose of this study was to examine the usefulness of perfusion-weighted MR imaging with a single-shot gradient echoplanar sequence in characterizing hepatic tumors. SUBJECTS AND METHODS: Perfusion-weighted imaging was performed in 61 patients with 91 confirmed hepatic tumors (14 hemangiomas, 19 metastases, and 58 hepatocellular carcinomas). The perfusion-weighted imaging was started at the time of administration of 0.1 mmol/kg of gadolinium, and images were continuously obtained every 2 sec for 88 sec. Time-intensity curves for all the tumors were created for quantitative analysis. Patterns of enhancement were also evaluated. RESULTS: Changes in signal intensity that occurred throughout examination differed in three types of tumor. Transient signal intensity decreases in the perfusion phase significantly differed in three types of tumors (46% in hepatocellular carcinoma, 48% in hemangioma, and 15% in metastasis, p < .05 for hepatocellular carcinoma versus metastasis and for hemangioma versus metastasis). Signal intensity recovered rapidly for hepatocellular carcinoma and metastasis, whereas recovery was slower for hemangioma. Final signal intensity recovery was 94% in hepatocellular carcinoma, 91% in metastasis, and 54% in hemangioma compared with their initial signal intensities. (p < .05 for hepatocellular carcinoma versus hemangioma and for hemangioma versus metastasis.) The enhancement patterns also differed in three types of tumor. CONCLUSION: Perfusion-weighted imaging with a gradient echoplanar sequence provides real-time mapping of many points along the enhancement profile curves because of its excellent temporal resolution. Therefore, it accurately characterizes hepatic tumors based on their different negative-enhancement patterns.

Percutaneous treatment of liver abscesses: needle aspiration versus catheter drainage.

Year 1998
Rajak CL. Gupta S. Jain S. Chawla Y. Gulati M. Suri S.
Department of Radio-Diagnosis, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
OBJECTIVE: This study was designed to determine and compare the efficacy of sonographically guided percutaneous needle aspiration and percutaneous catheter drainage in the treatment of liver abscesses. SUBJECTS AND METHODS: In a randomized study, 50 patients (38 males and 12 females; age range, 2-72 years; average age, 35 years) with liver abscesses (amebic, 20; pyogenic, 11; indeterminate, 19) underwent either percutaneous needle aspiration (n = 25) or catheter drainage (n = 25) along with appropriate antimicrobial therapy. In patients assigned to the needle aspiration group, an 18-gauge needle was used to aspirate the abscess cavity. Repeated aspiration was attempted only once in each patient not responding to the first aspiration; nonresponse to the second aspiration was considered failure of treatment, and these patients were given catheter drainage (however, these patients were not included in the catheter drainage group). For catheter drainage, 8- to 12-French catheters were introduced into the abscess cavity using the Seldinger technique. In patients with multiple abscesses (seven in aspiration group and five in catheter group), all the abscesses except those smaller than 3 cm were subjected to percutaneous treatment. Patients were followed up to assess the outcome of the percutaneous treatment, length of hospital stay, and development of any complications. Sonography was performed every third day during hospitalization. After discharge of the patient, periodic clinical and sonographic examinations were done until total resolution of abscesses was achieved. RESULTS: Although percutaneous needle aspiration was successful in only 15 (60%) of the 25 patients after one (n = 11) or two (n = 4) aspirations, catheter drainage was curative in all 25 patients (100%) (p < .05). Among the successfully treated patients, the average time for clinical improvement and the mean hospital stay were similar in the two treatment groups. Although the average time needed for a 50% reduction in the size of the abscess cavity was significantly (p < .05) greater in the aspiration group than in the catheter group (11 days versus 5 days), the average time taken for total resolution of abscess was the same (15 weeks) in both groups. No major complications were encountered. No relapse was documented on clinical and sonographic examination during follow-up, which ranged from 8 to 37 weeks. CONCLUSION: Our results show that percutaneous catheter drainage is more effective than needle aspiration in the treatment of liver abscesses. Needle aspiration, if limited to two attempts, has a high failure rate.

Cystic fibrosis: a system for assessing and predicting progression.

Year 1998
Cleveland RH. Neish AS. Zurakowski D. Nichols DP. Wohl ME. Colin AA.
Department of Radiology, Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.
OBJECTIVE: This study presents a radiography-based database scoring changes over time in a large population of patients with cystic fibrosis. The purpose of this database is to provide comparison for groups of patients undergoing experimental treatment to assess effect of the treatment. The data may also be used to compare individuals with their age-matched cohorts with cystic fibrosis. MATERIALS AND METHODS: From 230 patients, 3038 chest radiographs were scored using the Brasfield system. The scores from radiographs from all the patients were individually plotted for age, and a single age-based severity curve was created. The age-based severity curve was compared with similar curves derived from pulmonary function studies of a subset of the same patient population. RESULTS: We found high inter- and intraobserver reliability. The difference between the observers averaged 1.3 Brasfield points, the scale of which ranges up to 25 points. The age-based severity curve was presented as mean Brasfield scores versus age (birth to > 30 years) plotted with 95% confidence limits; the curve was also plotted in percentiles. The rate of decline of this curve was similar to the decline of pulmonary function studies in this patient population. CONCLUSION: The age-based curve, a structural anatomic parameter, differs from pulmonary function studies, which are functional. Thus the age-based severity curve provides an additional, independent basis for comparison between groups and individuals. It may be used for the initial assessment of lung disease and for gauging and predicting the rate of decline. The curve may be used as a long-range outcome criterion to evaluate new treatments in groups of patients with cystic fibrosis.

Helical CT pneumocolon to assess colonic tumors: radiologic-pathologic correlation.

Year 1998
Harvey CJ. Amin Z. Hare CM. Gillams AR. Novelli MR. Boulos PB. Lees WR.
Department of Medical Imaging, The Middlesex Hospital, University College Hospitals Trust, London, United Kingdom.
OBJECTIVE: The objective of this study was to determine the accuracy of helical CT pneumocolon in the staging of colonic carcinomas. SUBJECTS AND METHODS: Fifty-two patients (27 men, 25 women; age range, 40-88 years old; mean age, 67 years old) with known or strongly suspected colonic disorders underwent CT pneumocolon. After bowel cleansing, administration of smooth muscle relaxant, and rectal air insufflation, CT pneumocolon was performed with 5-mm collimation, 2.5-mm reconstruction interval, and a pitch of 1.5. Two contrast administration protocols were used. Twelve patients received 100 ml of i.v. contrast material that was injected at 3 ml/sec; scan delay was 45 sec. The other 40 patients received 150 ml of contrast material at 5 ml/sec; scan delay was 25 sec. Images were prospectively evaluated. All patients had pathologic confirmation: 46 patients had resections and six patients had endoscopic biopsies. RESULTS: Diagnostic images were obtained in 47 of 52 patients. In the 47 patients, there were 38 colonic carcinomas (one synchronous), nine diverticular strictures, eight polyps, one ischemic stricture, and one normal study. Thirty of 38 carcinomas were correctly staged by CT. Sensitivity and specificity for serosal infiltration were 100% (35/35 carcinomas) and 33% (one of three carcinomas), respectively; sensitivity and specificity for lymph node involvement were 56% (nine of 16 carcinomas) and 95% (21/22 carcinomas), respectively. Four polyps that were smaller than 5 mm in diameter were not revealed by CT. Twelve of 14 benign lesions were correctly diagnosed and two were believed to be malignant. No malignant lesion was misdiagnosed. CONCLUSION: CT pneumocolon gave an overall staging accuracy of 79% in 38 carcinomas.

Helical CT with only colonic contrast material for diagnosing diverticulitis: prospective evaluation of 150 patients.

Year 1998
Rao PM. Rhea JT. Novelline RA. Dobbins JM. Lawrason JN. Sacknoff R. Stuk JL.
Department of Radiology, Massachusetts General Hospital, Boston 02114, USA.
OBJECTIVE: We prospectively evaluated a helical CT technique in which contrast material is administered only through the colon for the imaging of suspected diverticulitis. SUBJECTS AND METHODS: One hundred fifty consecutive patients who presented to our emergency department with clinically suspected diverticulitis underwent helical abdominal CT after contrast material was administered only through the colon. CT findings of diverticulitis included diverticula, muscular wall hypertrophy, focal colonic wall thickening, and pericolonic fat stranding. CT results were correlated with clinical follow-up (all patients) and with pathologic findings (41 patients). RESULTS: A final clinical diagnosis of diverticulitis was made in 64 patients (43%), of whom 62 (97%) had CT results positive for diverticulitis. Of the 86 patients for whom diverticulitis was clinically excluded, all (100%) had CT results that were negative for diverticulitis. CT interpretations had a sensitivity of 97%, a specificity of 100%, a positive predictive value of 100%, a negative predictive value of 98%, and an overall accuracy of 99%. Alternative diagnoses were noted on CT in 50 (58%) of 86 patients who did not have diverticulitis and included 50 (78%) of the 64 patients in whom an alternative condition other than nonspecific abdominal pain was established. CONCLUSION: Helical CT obtained after contrast material administered only through the colon is accurate (99%) for confirming or excluding clinically suspected diverticulitis and for suggesting alternative conditions (78%) when they are present. This CT technique avoids the risks, discomforts, and costs of oral and i.v. contrast material administration and allows immediate scanning.

Sonographic appearance of benign and malignant conditions of the colon.

Year 1998
Truong M. Atri M. Bret PM. Reinhold C. Kintzen G. Thibodeau M. Aldis AE. Chang Y.
Department of Radiology, M. D. Anderson Cancer Center, The University of Texas, Houston 77030, USA.
OBJECTIVE: The objective of this study was to compare the sonographic appearance of different abnormalities of the colon to evaluate the role of sonography in their differential diagnosis. MATERIALS AND METHODS: We retrospectively reviewed videotaped sonographic examinations of 99 patients with proven diagnoses that included diverticulitis (n = 35), malignancy (n = 20), Crohn's disease (n = 16), pseudomembranous colitis (n = 14), ischemic colitis (n = 9), and ulcerative colitis (n = 5). Data were collected with regard to gut features, including the site of colonic involvement, associated small-bowel involvement, length of diseased segment, stratification, luminal contents, pneumatosis, and diverticula. Perigut features evaluated included abnormal fat, abscess, fistula, and ascites. RESULTS: On sonography, the following features were statistically significant (p < .05). Involvement of the small bowel was more common in patients with Crohn's disease than in the remainder of the study population (44% versus 1%). Left-sided colonic disease (91% versus 38%), diverticula (91% versus 3%), and perigut findings (91% versus 57%), including abnormal fat (83% versus 39%) and abscess (34% versus 8%), were features that indicated diverticulitis. Malignant conditions were more common in patients with a greater wall thickness (mean, 26.2 mm versus 10.2 mm), asymmetric involvement (85% versus 39%), loss of stratification (85% versus 20%), absence of perigut findings (65% versus 22%), and involvement of a short diseased segment (70% versus 16%). Involvement of the entire colon (50% versus 2%), luminal contents (64% versus 28%), and ascites (64% versus 26%) were features suggesting pseudomembranous colitis. CONCLUSION: Although the sonographic appearances of abnormalities of the colon overlap, some sonographic features are helpful in the differential diagnosis of colonic abnormalities.

MR imaging of the small bowel using the HASTE sequence.

Year 1998
Lee JK. Marcos HB. Semelka RC.
Department of Radiology, University of North Carolina School of Medicine, Chapel Hill 27599-7510, USA.
OBJECTIVE: To establish the normal MR appearance of small bowel on half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequence and to determine the ability of HASTE to reveal small-bowel disease. MATERIALS AND METHODS: HASTE images in 50 patients without small-bowel disease were reviewed retrospectively to determine the normal MR appearance of small bowel. All patients fasted for at least 6 hr. The images of 18 patients with proven small-bowel abnormalities that were obtained with the HASTE sequence were also reviewed retrospectively by one observer unaware of the findings. The ability to characterize small-bowel diseases using the HASTE sequence was assessed. RESULTS: In the 50 patients with normal small bowel, no fluid was seen in the jejunum and ileum loops in four (8%). Fluid was present in less than 25% of small-bowel loops in 20 patients (40%), 25-50% of small-bowel loops in 20 patients (40%), and 50-75% of small-bowel loops in six patients (12%). Equal amounts of fluid were present in the jejunum and ileum in 30 patients (60%). More fluid was seen in the jejunum than the ileum in 16 patients (32%) and the reverse was true in four patients (8%). The mean diameter of the jejunum was 2.1 cm (SD = 0.34 cm) and of the ileum, 1.9 cm (SD = 0.41 cm). The thickness of the small-bowel wall and valvulae conniventes averaged 2 mm. Findings of dilatation of the bowel lumen and increased thickness of the bowel wall and valvulae conniventes were identified in 18 patients with small-bowel abnormalities. CONCLUSION: The normal and abnormal small bowel can be assessed using the HASTE sequence.

Fast MR imaging and the detection of small-bowel obstruction.

Year 1998
Regan F. Beall DP. Bohlman ME. Khazan R. Sufi A. Schaefer DC.
Department of Imaging, The Johns Hopkins Bayview Medical Center, Baltimore, MD 21224, USA.
OBJECTIVE: Our aim was to determine whether fast MR imaging using the half-Fourier acquisition single-shot turbo spin-echo (HASTE) MR sequence is accurate for diagnosis of small-bowel obstruction. MATERIALS AND METHODS: Forty-three nonconsecutive patients with suspected small-bowel obstruction were evaluated with HASTE MR imaging during a 12-month period. Images were retrospectively assessed for the presence, level, and cause of bowel obstruction. Data were compared with results of conventional radiography and findings at surgery when available. RESULTS: Of the 43 patients imaged, 29 patients had small-bowel obstruction revealed by unenhanced or contrast-enhanced radiography or by CT. Surgical confirmation was available in 21 patients. Small-bowel obstruction was shown by HASTE MR imaging in 26 (90%) of these 29 patients. HASTE MR images showed the correct level of obstruction in 19 (73%) of the 26 patients and showed the cause of obstruction in 13 (50%) of the 26 patients. CONCLUSION: With a high degree of accuracy, HASTE MR imaging can show the presence and level of small-bowel obstruction.

A new design of the esophageal Wallstent endoprosthesis resistant to distal migration.

Year 1998
Adam A. Morgan R. Ellul J. Mason RC.
Department of Radiology, Guy's Hospital, London, United Kingdom.
OBJECTIVE: Because plastic-covered metallic stents used in the palliation of patients with unresectable esophageal cancer are associated with significant rates of migration, particularly when the lower end of the stent projects into the gastric fundus, the purpose of this study was to establish whether two new prototype designs of the Wallstent esophageal endoprosthesis are prone to migration. SUBJECTS AND METHODS: A cylindrical stent and a conical stent were studied. Both designs included plastic covering inside the metallic mesh. In addition, the conical device incorporated a variation in the braiding angle between the upper and lower parts of the endoprosthesis. Ten conical stents and eight cylindrical stents were inserted in 18 patients with tumors involving the gastroesophageal junction who were followed up with esophagography and endoscopy. RESULTS: All insertions of stents were successful. Two cylindrical stents (25%) migrated distally. Two conical stents (20%) migrated proximally. One perforation occurred that was associated with distal migration of a cylindrical stent. CONCLUSION: The frequency of distal migration of cylindrical stents is unacceptably high. Conical stents are resistant to distal migration, although improvements in design are required to deal with the problem of proximal migration.

Lipomas of the pancreas.

Year 1998
Katz DS. Nardi PM. Hines J. Barckhausen R. Math KR. Fruauff AA. Lane MJ.
Department of Radiology, Winthrop University Hospital, Mineola, NY 11501, USA.
OBJECTIVE: The purpose of this study was to describe the CT findings of pancreatic lipomas in four patients. CONCLUSION: In all four cases, the lipoma was revealed incidentally on CT scans obtained for other reasons. CT scans were diagnostic, showing well-circumscribed masses within the pancreas composed almost entirely of fat, with a few scattered vessels or septa or both, which ranged in size from 1.4 x 2.0 cm to 4.5 x 5.3 cm in the axial plane. Pancreatic lipomas are rare, usually incidental tumors and, as with lipomas found elsewhere in the body, conservative management is often indicated.

Neoplastic pancreaticobiliary duct obstruction: evaluation with breath-hold MR cholangiopancreatography.

Year 1998
Schwartz LH. Coakley FV. Sun Y. Blumgart LH. Fong Y. Panicek DM.
Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA.
OBJECTIVE: The purpose of this study was to investigate the use of breath-hold single-shot fast spin-echo MR cholangiopancreatography in neoplastic pancreaticobiliary duct obstruction. MATERIALS AND METHODS: Breath-hold MR cholangiopancreatography was performed for preoperative examination of 32 consecutive patients with pathologically confirmed neoplastic obstruction of the biliary tract or pancreatic duct using a single-shot fast spin-echo sequence. Two observers, unaware of clinical or pathologic findings, independently reviewed the MR cholangiopancreatograms to assess level of obstruction and site of underlying tumor. Pathologic diagnoses, based on surgical or CT-guided biopsy specimens, were pancreatic tumor (n = 12), gallbladder cancer (n = 9), intrahepatic cancer (n = 9), and ampullary cancer (n = 2). RESULTS: On the basis of conventional cholangiography, CT, and surgical findings, 20 patients had isolated bile duct obstruction, 11 patients had combined pancreatic and bile duct obstruction, and one patient had isolated pancreatic duct obstruction. Isolated bile duct obstruction was classified as lobar (n = 5), hilar (n = 12), or distal (n = 3). These levels of obstruction were correctly identified in 27 (84%) and 28 (88%) of the 32 cases by the two observers. The site of the underlying tumor was identified in 27 (84%) and 29 (91%) cases by the two observers. Good interobserver agreement was reached for both level of obstruction (kappa = .70) and identification of tumor site (kappa = .75). CONCLUSION: Breath-hold single-shot fast spin-echo MR cholangiopancreatography is accurate in identifying the level of obstruction and the site of underlying tumor in neoplastic pancreaticobiliary duct obstruction, with good interobserver agreement.

MR imaging during arterial portography for assessment of hepatocellular carcinoma: comparison with CT during arterial portography.

Year 1998
Yu JS. Kim KW. Lee JT. Yoo HS.
Department of Radiology, YongDong Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea.
OBJECTIVE: The purpose of this study was to document the usefulness of MR imaging during arterial portography (MRAP) versus CT during arterial portography (CTAP) in the diagnosis and assessment of hepatocellular carcinoma. SUBJECTS AND METHODS: In addition to static T1- and T2-weighted MR imaging, MRAP was performed immediately after hepatic angiography through contrast material injection into intraarterially placed catheters (superior mesenteric or splenic artery) in 21 patients with nodular hepatocellular carcinoma. CTAP was performed afterward for each patient. The sensitivity and specificity of MRAP for lesion detection and the differential diagnosis of hepatocellular carcinoma were compared with the sensitivity and specificity of CTAP. RESULTS: MRAP revealed more perfusion defects (n = 56) than did CTAP (n = 46). The sensitivity for detection of hepatocellular carcinoma was higher for MRAP (94%) than for CTAP (83%); however, the difference was not statistically significant (p > .05). More hepatocellular nodules with unknown malignant potential were revealed on MRAP (n = 7) than on CTAP (n = 2). For the differential diagnosis of perfusion defects commonly revealed by both techniques, more benign lesions and pseudolesions (n = 14) were shown on MRAP through the combined interpretation with static images than on unenhanced and contrast-enhanced CTAP (n = 11). CONCLUSION: Because of its high sensitivity and its ability to enable radiologists to differentiate benign from malignant conditions, MRAP may have merit compared with CTAP in the assessment of hepatocellular carcinoma.

Computed radiography of the chest in patients with paraesophageal varices: diagnostic accuracy and characteristic findings.

Year 1998
Lee SJ. Lee KS. Kim SA. Kim TS. Hwang JH. Lim JH.
Department of Radiology, Samsung Medical Center, College of Medicine, Sung Kyun Kwan University, Seoul, South Korea.
OBJECTIVE: The purpose of our study was to determine the diagnostic accuracy of computed radiography of the chest in the detection of paraesophageal varices and to describe the characteristic radiographic findings. SUBJECTS AND METHODS: From June 1995 through May 1997, in 100 consecutive patients, portal hypertension was diagnosed through both clinical and radiologic evidence. Computed radiographs of the chest and hepatic helical CT scans of these 100 patients with portal hypertension and 20 control subjects were analyzed by two chest radiologists and one abdominal radiologist, who were not aware of the results of the other study. RESULTS: On CT, paraesophageal varices were seen in 38 (38%) of 100 patients with portal hypertension. Overall, the sensitivity, specificity, and accuracy of chest computed radiography in the detection of paraesophageal varices were 53% (20/38), 90% (74/82), and 78% (94/120), respectively. In the patients with paraesophageal varices, splenomegaly (29/38, 76%), lateral displacement or obliteration of the inferior portion of the azygoesophageal interface (18/38, 47%), obliteration or nodularity of the inferior portion of the descending thoracic aorta interface (9/38, 24%), lateral displacement of the right inferior paraspinal interface (6/38, 16%), lateral displacement of the left inferior paraspinal interface (4/38, 11%), and varices in the left inferior pulmonary ligament (1/38, 3%) were seen on chest computed radiographs. Paraesophageal varices smaller than the diameter of the descending thoracic aorta (usually

Preaortic esophageal veins: CT appearance.

Year 1998
Ibukuro K. Tsukiyama T. Mori K. Inoue Y.
Department of Radiology, Mitsui Memorial Hospital, Tokyo, Japan.
OBJECTIVE: The purpose of this study was to describe the CT imaging features of preaortic esophageal veins in 10 patients with liver cirrhosis. CONCLUSION: Preaortic esophageal veins deriving from the paraesophageal varices course anterior to the descending aorta and drain into the hemiazygos vein. Preaortic esophageal veins are anatomically identical to extrinsic esophageal veins. The diameter of the veins we studied ranged from 1 to 8 mm (mean, 3.1 mm). Two preaortic esophageal veins were noted in each of two patients.

One-step needle aspiration and lavage for the treatment of abdominal and pelvic abscesses.

Year 1998
Wroblicka JT. Kuligowska E.
Department of Radiology, Boston Medical Center, MA 02118, USA.
OBJECTIVE: This retrospective study was undertaken to show the efficacy and safety of one-step needle aspiration and lavage for the treatment of nonenteric, nonpancreatic abdominal and pelvic abscesses. MATERIALS AND METHODS: Eighty-two nonconsecutive patients (age range, 4-81 years old) with 97 abdominal and pelvic abscesses were treated over 16 years with a one-step percutaneous needle aspiration and lavage technique. Abscesses were drained with sonographic or CT guidance in a single session. An 18-gauge needle was used for aspiration and repeated saline lavage; no drainage catheter was left in place. For collections that appeared multiloculated, needle repositioning and repeated aspiration and lavage were performed during the single session. All patients received i.v. antibiotics. RESULTS: Eighty-seven (90%) of 97 abscesses in 72 of 82 patients were successfully treated, including 17 (85%) of 20 abscesses that were multiloculated. The only two complications were transient sepsis in one patient and hemorrhage in one patient that resolved with transfusion and conservative treatment. Needle aspiration and lavage failures were associated with diffuse peritonitis, occult malignancy, unsuspected enteric communication, and a dropped surgical clip. CONCLUSION: Percutaneous needle aspiration and lavage can be a safe, effective alternative to the more conventional treatment of prolonged catheter drainage. In selected patients, including certain patients with multiloculated abscesses, one-step needle aspiration and lavage should be considered as the initial method of treatment.

Sonography of the female urethra.

Year 1998
Siegel CL. Middleton WD. Teefey SA. Wainstein MA. McDougall EM. Klutke CG.
Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA.
OBJECTIVE: The purpose of this study was to explore the role of sonography for women with urethral symptoms and a suspected urethral diverticulum. SUBJECTS AND METHODS: Nineteen women with urethral symptoms underwent voiding cystourethrography (VCUG) and transvaginal, transperineal, and urethral sonography (using a catheter-based transducer). VCUGs and sonograms were evaluated for diverticula, defined on sonography by direct visualization of the neck connecting the periurethral sac with the urethral lumen. The diverticular neck, size, location, and shape were noted. Lesions revealed by sonography as not connected to the urethra were also noted. RESULTS: Of 19 women, 14 had urethral diverticula and one had two diverticula, for a total of 15 diverticula. On sonography the diverticula ranged in diameter from 2 mm to 5 cm. Both sonography and VCUG showed 13 of the 15 diverticula. In addition, sonography revealed two infected periurethral cysts, a periurethral leiomyoma, a diffuse urethritis, and scarring or deformity of one patient's urethra from a prior diverticulectomy. On sonography, eight of the 13 diverticula wrapped around more than 50% of the urethral circumference. The neck was precisely seen (by definition) in 13 of 15 diverticula on sonography and in two of 13 diverticula on VCUG. CONCLUSION: Sonography is useful in this group of women with urethral symptoms and suspected urethral diverticula. It provides information on the extent and location of the diverticular neck, both of which are important in surgical excision. Also, sonography provides information on lesions not connected to the urethra. Sonography may prove useful in a broader group of women with urethral symptomatology.

Placement of retrograde nephroureteral stents through ileal conduits.

Year 1998
Zaleski GX. Funaki B. Newmark G.
Department of Radiology, The University of Chicago Hospitals, IL 60637, USA.
OBJECTIVE: Our objective was to evaluate retrograde nephroureteral stent placement in patients with ileal conduits. CONCLUSION: In patients with ureteral complications after cystectomy and ileal diversion, retrograde nephroureteral stent placement should be the treatment of choice to reduce patient morbidity, increase patient comfort, and facilitate stent care.

Sonographic detection of echogenic fluid and correlation with culdocentesis in the evaluation of ectopic pregnancy.

Year 1998
Chen PC. Sickler GK. Dubinsky TJ. Maklad N. Jacobi RL. Weaver JE.
Department of Radiology, The University of Texas Health Sciences Center, Houston 77030, USA.
OBJECTIVE: Because the presence of echogenic fluid on transvaginal sonography has been shown to correlate well with hemoperitoneum in patients with possible ectopic pregnancy, the aim of this study was to compare echogenic fluid on sonography with the results of culdocentesis in predicting hemoperitoneum. MATERIALS AND METHODS: Free fluid on transvaginal sonography and the results of culdocentesis were correlated with the presence or absence of hemoperitoneum in 46 patients at surgery. Forty ectopic pregnancies and six nonectopic pregnancies were found. Echogenic fluid was the criterion used to establish hemoperitoneum on sonography. For statistical analysis, negative and nondiagnostic culdocentesis results were combined. The sensitivity, specificity, and positive and negative predictive values of each diagnostic technique were compared. RESULTS: In 40 of 46 patients with ectopic pregnancy, the sensitivity and specificity of echogenic fluid for establishing hemoperitoneum were 100% and 100%, respectively, compared with 66% and 80%, respectively, for culdocentesis. More important, the negative predictive value of a nondiagnostic culdocentesis was 25% compared with 100% for echogenic fluid in the ectopic subgroup of patients. In two patients with incomplete abortions, sonography failed to detect small amounts of hemoperitoneum at surgery performed 4 hr and 7 days after sonography. CONCLUSION: Sonography is more sensitive than culdocentesis in the detection of hemoperitoneum. Culdocentesis is invasive, and nondiagnostic results cannot be used to exclude hemoperitoneum. Culdocentesis should play no role in the evaluation of ectopic pregnancy except in the unusual circumstance in which high-resolution sonography cannot be readily performed.

Small-bowel obstruction associated with sigmoid diverticulitis: CT evaluation in 16 patients.

Year 1998
Kim AY. Bennett GL. Bashist B. Perlman B. Megibow AJ.
Department of Radiology, NYU Medical Center, New York 10016, USA.
OBJECTIVE: The purpose of this study was to identify acute sigmoid diverticulitis as a cause of small-bowel obstruction and to describe the CT findings. CONCLUSION: CT scanning enabled accurate preoperative diagnosis of colonic diverticulitis as the cause of the small-bowel obstruction, thereby allowing proper management and surgical planning.

Pancreatic tumors: comparison of dual-phase helical CT and endoscopic sonography.

Year 1998
Legmann P. Vignaux O. Dousset B. Baraza AJ. Palazzo L. Dumontier I. Coste J. Louvel A. Roseau G. Couturier D. Bonnin A.
Department of Radiology, Universite Rene Descartes, Hopital Cochin, Paris, France.
OBJECTIVE: The purpose of this study was to compare dual-phase helical CT and endosonography for the diagnosis and staging of pancreatic tumors. SUBJECTS AND METHODS: Thirty patients with suspected pancreatic tumors underwent endosonography and dual-phase helical CT. A pathologic diagnosis was obtained in all cases with surgery (n = 23) or biopsy (n = 7), resulting in 27 neoplasms. Dual-phase helical CT and endosonographic findings were correlated with surgical and pathologic findings to determine diagnosis and resectability of pancreatic tumors. RESULTS: Overall diagnostic sensitivity was 92% for dual-phase helical CT and 100% for endosonography (p = .45). Overall accuracy for staging of pancreatic tumors was 93% for both dual-phase helical CT and endosonography. Overall accuracy for predicting resectability was 90% for both dual-phase helical CT and endosonography. Accuracy of predicting unresectability was 100% for dual-phase helical CT and 86% for endosonography (p > .80). Differences were not considered statistically significant. CONCLUSION: Dual-phase helical CT and endoscopic sonography do not differ significantly for diagnosis and assessment of resectability of pancreatic tumors.

Autoimmune pancreatitis: CT and MR characteristics.

Year 1998
Irie H. Honda H. Baba S. Kuroiwa T. Yoshimitsu K. Tajima T. Jimi M. Sumii T. Masuda K.
Department of Radiology, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
OBJECTIVE: Our goal was to elucidate the CT and MR imaging characteristics in patients with autoimmune pancreatitis, which is a reversible chronic pancreatitis with an autoimmune cause. CONCLUSION: On CT and MR imaging, a capsulelike rim, which is thought to correspond to an inflammatory process involving peripancreatic tissues, appears to be a characteristic finding of autoimmune pancreatitis. Also, diffuse pancreatic enlargement along with hypointensity on T1-weighted MR images and delayed enhancement on dynamic CT and MR studies are other features of this disorder.

Meckels diverticulum: angiographic findings in 16 patients.

Year 1998
Mitchell AW. Spencer J. Allison DJ. Jackson JE.
Department of Imaging, Imperial College of Science, Technology and Medicine, Hammersmith Hospital, London, United Kingdom.
OBJECTIVE: The purpose of this study was to assess the sensitivity of angiography in revealing the vitellointestinal artery or other arteriographic abnormalities in patients in whom surgery subsequently proved Meckel's diverticulum. MATERIALS AND METHODS: From the 36 patients who had undergone a Meckel's diverticulectomy between 1980 and 1997 at Hammersmith Hospital or a referring hospital, we selected 18 who had undergone preoperative angiography at our institution. Case notes and angiograms of these 18 patients were reviewed for the presence of a persistent vitellointestinal artery or other angiographic evidence of a Meckel's diverticulum. RESULTS: Angiograms of 16 of 18 patients were available for review. A striking male preponderance existed (male:female = 13:3). Mean age was 28 years (range, 12-65 years). In 11 (69%) of the 16 patients, a persistent vitellointestinal artery was seen that had been noted at the time of the study and reported before surgery for nine patients. Other angiographic abnormalities at the site of the Meckel's diverticulum were present in four patients and included a vascular blush, early venous return, and arterial irregularity. CONCLUSION: Angiography will show a persistent vitellointestinal artery in most individuals with a Meckel's diverticulum who present with chronic gastrointestinal bleeding. However, the recognition of a persistent vitellointestinal artery may be difficult because of overlying vessels, and superselective catheterization of distal ileal arteries may be necessary.

Helical CT versus CT arterial portography in the detection of hepatic metastasis of colorectal carcinoma.

Year 1998
Valls C. Lopez E. Guma A. Gil M. Sanchez A. Andia E. Serra J. Moreno V. Figueras J.
Institut de Diagnostic per la Imatge, Hospital Duran i Reynals, Ciutat Sanitaria i Universitaria de Bellvitge, Barcelona, Spain.
OBJECTIVE: The study is a prospective comparison of helical CT with nonhelical CT arterial portography (CTAP) in the detection of liver metastases from colorectal carcinoma, using surgical and histologic findings as the gold standard. SUBJECTS AND METHODS: Thirty-five patients with colorectal carcinoma and suspected liver metastases were prospectively examined with helical CT and CTAP before surgery. In nine cases, surgery was not performed. In the remaining 26 patients, imaging results were correlated with surgical and pathologic findings. Three radiologists prospectively assessed metastatic involvement with both techniques. The results were compared with pathologic and surgical findings on a lesion-by-lesion basis. In a second phase, three radiologists not directly concerned in the design of the study independently assessed metastatic involvement of the liver as revealed on helical CT and CTAP on a segment-by-segment basis with a five-level scale of confidence. Results were analyzed by receiver operating characteristic methods. RESULTS: The results of the histologic study disclosed 50 metastatic lesions. Helical CT had a sensitivity of 76% (38/50) and a positive predictive value of 90%. CTAP had a sensitivity of 74% (37/50) and positive predictive value of 69%. Receiver operating characteristic analysis revealed a greater area under the curve (Az index), 0.96, for helical CT than for CTAP (0.86). Differences were statistically significant (p < .001). CONCLUSION: Helical CT is superior to nonhelical CTAP in the detection of hepatic metastases from colorectal carcinoma.

Air trapping on expiratory high-resolution CT scans in the absence of inspiratory scan abnormalities: correlation with pulmonary function tests and differential diagnosis.

Year 1998
Arakawa H. Webb WR.
Department of Radiology, University of California, San Francisco 94143-0628, USA.
OBJECTIVE: We wish to describe the differential diagnosis and pulmonary function correlates of patients with normal findings on inspiratory high-resolution CT (HRCT) scans who showed air trapping on expiratory scans. MATERIALS AND METHODS: HRCT scans in 273 consecutive patients with suspected diffuse lung disease were reviewed. HRCT consisted of inspiratory scans at 1- to 2-cm intervals and expiratory scans at three levels. Studies considered to show expiratory air trapping were divided into two groups, one having normal findings on inspiratory scans and one having abnormal findings on inspiratory scans. Pulmonary function test results in these groups were compared with a group of patients who had normal findings on inspiratory and expiratory HRCT scans. RESULTS: Forty-five patients showed air trapping on expiratory HRCT scans. Of these 45 patients, inspiratory high-resolution CT scans showed abnormal findings in 36 (bronchiectasis, bronchiolitis obliterans, asthma, chronic bronchitis, and cystic fibrosis). In the remaining nine patients, inspiratory HRCT had normal findings; conditions in these nine patients included bronchiolitis obliterans (n = 5), asthma (n = 3), and chronic bronchitis (n = 1). Results of pulmonary function tests in patients with air trapping and normal findings on inspiratory scans were intermediate, falling between those of patients with normal findings on inspiratory and expiratory HRCT scans and those of patients with air trapping and abnormal findings on inspiratory scans. CONCLUSION: Air trapping on expiratory HRCT scans in patients with normal findings on inspiratory scans is most often associated with bronchiolitis obliterans and asthma. Obtaining expiratory scans in patients who may have one of these diseases is recommended.

Virtual bronchoscopy for directing transbronchial needle aspiration of hilar and mediastinal lymph nodes: a pilot study.

Year 1998
McAdams HP. Goodman PC. Kussin P.
Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA.
OBJECTIVE: We conducted a preliminary investigation of virtual bronchoscopy as a guide for transbronchial needle aspiration of hilar or mediastinal lymph nodes to assess the usefulness of this technique. CONCLUSION: Virtual bronchoscopic images derived from routine helical CT scans were useful for directing transbronchial needle aspiration in a clinical setting. In addition, virtual bronchoscopy may have been responsible for improving the yield of transbronchial needle aspirations done by our bronchoscopists when 22-gauge needles were used.

Intraperitoneal rhabdomyosarcoma in children: incidence and imaging characteristics on CT.

Year 1998
Chung CJ. Fordham L. Little S. Rayder S. Nimkin K. Kleinman PK. Watson C.
Department of Radiology, UNC School of Medicine, Chapel Hill 27599-7510, USA.
OBJECTIVE: The purpose of this study was to determine the incidence and CT imaging features of intraperitoneal rhabdomyosarcoma in children. CONCLUSION: Approximately 10% of children with rhabdomyosarcoma may have intraperitoneal neoplastic involvement either at the time of diagnosis or subsequently. On CT, intraperitoneal rhabdomyosarcomas are associated with ascites, enhancing nodules, masses, a pseudomyxoma peritonei-like appearance, and omental caking.