Radiology

Hypervascular hepatocellular carcinoma: evaluation of hemodynamics with dynamic CT during hepatic arteriography.

Ueda K. Matsui O. Kawamori Y. Nakanuma Y. Kadoya M. Yoshikawa J. Gabata T. Nonomura A. Takashima T.
Department of Radiology, Kanazawa University School of Medicine, Japan.
PURPOSE: To assess the hemodynamics and the main drainage vessel of hypervascular hepatocellular carcinoma. MATERIALS AND METHODS: Single-level dynamic computed tomography during hepatic arteriography (CTHA) was performed in 32 patients with hepatocellular carcinoma. Carcinoma was confirmed with histologic (n = 9) or clinical (n = 23) examination results. Single-level CTHA findings were retrospectively analyzed. Histologic specimens from 40 livers with hepatocellular carcinoma were also examined, with special attention to vessels along the rim of the lesion. RESULTS: Contrast material enhancement on single-level CTHA images occurred in four phases: (a) inflow of the contrast material into tumor, (b) tumor enhancement, (c) inflow of the contrast material into adjacent liver, and (d) corona enhancement of adjacent liver. Corona enhancement was seen in all lesions. A bright branching structure in the corona enhancement area, suggestive of a portal venule, was visible at the start of adjacent liver staining in 21 lesions. Continuity between a tumor sinusoid and a tiny vessel in the inner layer of the pseudocapsule was histologically confirmed in 10 of 40 specimens. Continuity between a tiny vessel in the inner layer and a portal vein in the outer layer of the pseudocapsule was confirmed with findings on serial sections from one liver. CONCLUSION: The main drainage of hepatocellular carcinoma lesions may be a protal venule.

Symptomatic hepatic cysts: treatment with single-shot injection of minocycline hydrochloride.

Cellier C. Cuenod CA. Deslandes P. Auroux J. Landi B. Siauve N. Barbier JP. Frija G.
Department of Gastroenterology, Universite Rene Descartes, Hopital Laennec, Paris, France.
PURPOSE: To assess the efficacy of percutaneous minocycline hydrochloride sclerotherapy in symptomatic hepatic cysts. MATERIALS AND METHODS: From November 1992 to June 1994, seven of eight consecutive adults with large symptomatic hepatic cysts (diameter, 55-130 mm) were treated with a single intracystic injection of minocycline hydrochloride in an ambulatory procedure. Five patients had a solitary cyst, and two had polycystic liver disease. The target cyst was punctured under ultrasound guidance and local anesthesia with a 22-gauge Chiba needle. Half of the cyst content was aspirated before injection of 100-500 mg of minocycline hydrochloride diluted in 5-25 mL of saline. The minocycline hydrochloride was left in the cyst at the end of the procedure. RESULTS: After a mean follow-up of 28 months (range, 24-42 months), all five patients with solitary cysts were asymptomatic and four had documented complete cyst regression; the two patients with multiple hepatic cysts showed only transient clinical improvement. CONCLUSION: Single-shot injection of minocycline hydrochloride is an effective treatment for symptomatic solitary hepatic cysts but is less effective in polycystic liver disease.

Transjugular intrahepatic portosystemic shunt creation in children: initial clinical experience.

Hackworth CA. Leef JA. Rosenblum JD. Whitington PF. Millis JM. Alonso EM.
Department of Radiology, University of Chicago Hospitals, IL 60637, USA.
PURPOSE: To assess an initial clinical experience with the creation of a transjugular intrahepatic portosystemic shunt (TIPS) in children. MATERIALS AND METHODS: Twelve consecutive patients with complications of portal hypertension underwent TIPS creation at our institution between July 1993 and September 1996. There were six boys and six girls aged 2 years 5 months to 16 years 10 months (median, 9 years 2 months) who weighed 13.9-80.9 kg (median, 27.65 kg). A standard radiographic technique was used. RESULTS: Thirteen procedures were performed to achieve 12 successful TIPS creations. One child with a reduced-size liver transplant had to undergo two procedures for a successful TIPS creation. No major procedural complications or morbidity occurred. In 10 children, TIPS patency was documented by means of pathologic inspection at orthotopic liver transplantation (median shunt duration, 53 days). Shunt stenosis developed in one child at 186 days but was treated successfully. Two children had functional shunts at 301 and 357 days, respectively. No episodes of repeat variceal hemorrhage were noted. One child developed postprocedural encephalopathy, which responded to medical therapy. CONCLUSION: This initial clinical experience suggests that TIPS creation is technically feasible and is as safe in children as in adults. TIPS creation can aid in the management of portal hypertension in children, especially in those needing temporary relief before liver transplantation.

Duodenitis in children: correlation of radiologic findings with endoscopic and pathologic findings.

Long FR. Kramer SS. Markowitz RI. Liacouras CA.
Department of Radiology, Columbus Children's Hospital, OH 43205-2696, USA.
PURPOSE: To determine the accuracy of barium studies in the diagnosis of duodenitis in children. MATERIALS AND METHODS: Seventy-five children (45 boys and 30 girls; mean age, 9 years) underwent upper gastrointestinal (GI) examinations. Twenty-four of the children had biopsy-proved duodenitis, and 51 were healthy control subjects. Radiologic findings were reviewed by two experienced, blinded observers and correlated with endoscopic and histologic results. Duodenal mucosal-fold thickness was measured on spot radiographs (20% magnification), and the extent of disease was evaluated. RESULTS: Of 15 children with mild duodenitis, 13 had normal radiologic findings and 11 had normal findings at esophagogastroduodenoscopy. Of nine children with severe duodenitis, all had friability or ulceration at endoscopy and mucosal-fold thickening of greater than or equal to 4 mm (> or = 3 mm in one infant aged less than 1 year) at upper GI examination. Mucosal-fold thickening was diffuse in patients with celiac, autoimmune, and adenovirus disease and was proximal in patients with peptic ulcer and Crohn disease. Of 51 control subjects, 50 had normal radiologic results, while 47 had normal endoscopic results. The sensitivity of upper GI examination for mild and severe duodenitis combined was 46% with a specificity of 98%, whereas endoscopy had a sensitivity of 54% and specificity of 92%. CONCLUSION: Mucosal-fold thickening was a specific sign of duodenitis in children and should be investigated. Upper GI examination yielded results similar to those at endoscopy.

Carcinoid metastases to the liver: role of triple-phase helical CT.

Paulson EK. McDermott VG. Keogan MT. DeLong DM. Frederick MG. Nelson RC.
Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA.
PURPOSE: To evaluate triple-phase helical computed tomography (CT) of carcinoid liver metastases. MATERIALS AND METHODS: Triple-phase helical CT was performed in 31 patients with proved carcinoid liver metastases. Hepatic arterial-dominant phase (HAP) and portal venous-dominant phase (PVP) images were obtained 20 and 70 seconds after intravenous iopamidol injection. Four independent readers reviewed each phase for lesion number, conspicuity, and attenuation relative to liver. Three readers reviewed each phase to determine which phase best showed the lesions. RESULTS: The lesions detected by readers 1-4 were as follows: noncontrast phase, 164, 177, 204, and 229 lesions; HAP, 178, 177, 214, and 238 lesions; and PVP, 180, 189, 215, and 250 lesions (P > .05). On HAP images, readers found that 80, 73, 96, and 102 lesions were hyperattenuating. Consensus indicated there were 206 focal lesions. Of these 206 lesions, 72, 72, and 62 lesions were best seen on the noncontrast phase, HAP, and PVP images, respectively. Six, 28, and six lesions were seen only on the noncontrast phase, HAP, and PVP images, respectively. Two patients had lesions seen only on the HAP images. CONCLUSION: The HAP and, to a lesser extent, the noncontrast phase provide added value in evaluating carcinoid liver metastasis.

Locally advanced rectal cancer: surgical complications after infusional chemotherapy and radiation therapy.

Janjan NA. Khoo VS. Rich TA. Evetts PA. Goswitz MS. Allen PK. Skibber JM.
Department of Radiation Oncology, University of Texas, M. D. Anderson Cancer Center, Houston 77030, USA.
PURPOSE: To compare the surgical complication rate after further experience with infusional chemotherapy and radiation therapy for locally advanced rectal cancer. MATERIALS AND METHODS: Preoperative radiation therapy (45 Gy in 25 fractions over 5 weeks) and concurrent continuous infusion of 5-fluorouracil (300 mg.m-2.d-1) were given to 117 patients with rectal cancer. Approximately 6 weeks after therapy, surgery was performed. RESULTS: The histopathologic cancer stages were Tis-2N0 in 30 patients (26%), T2N1 in six (5%), T3N0 in 24 (21%), T3N1 in 18 (15%), T4N0 in six (5%), and T4N1 in one (1%); a complete response to preoperative therapy was histopathologically confirmed in 32 patients. A decrease in cancer stage allowed a sphincter-saving procedure in 68 patients (58%) and abdominoperineal resection in 49 patients (42%). Only one patient developed fistula; nine patients, perioperative wound complications; and four patients, pelvic infection. In the authors' previously reported chemotherapy and radiation therapy results (same protocol), eight (22%) of 37 patients developed fistulas and five (14%) developed pelvic abscess; in the authors' previous experience with preoperative radiation therapy only (median total dose, 45 Gy; dose range, 40.0-59.4 Gy), results were similar. CONCLUSION: Surgical complications after chemotherapy and radiation therapy are statistically significantly (P < .05) reduced with further experience.

Acute colonic obstruction: clinical aspects and cost-effectiveness of preoperative and palliative treatment with self-expanding metallic stents--a preliminary report.

Binkert CA. Ledermann H. Jost R. Saurenmann P. Decurtins M. Zollikofer CL.
Department of Radiology, Kantonsspital Winterthur, Switzerland.
PURPOSE: Evaluation of clinical aspects and cost-effectiveness of use of self-expanding metallic stents in the treatment of acute colonic obstruction as either a preoperative procedure or palliation. MATERIALS AND METHODS: Thirteen consecutive patients, aged 49-83 years (mean, 67 years), with clinical and radiologic signs of colonic obstruction were treated as a preoperative procedure in 10 patients and as a palliative treatment in three. A total of 16 self-expanding metallic stents (diameter, 16 mm; length fully expanded, 56 mm) were implanted with combined fluoroscopic and endoscopic guidance. The costs (hospitalization, intensive care unit, stent placement, and surgery) were compared with costs for 13 surgically treated patients at the same hospital. RESULTS: Stent placement was successful in 12 of the 13 patients; all recovered from mechanical obstruction, and single-stage surgery was possible in eight of nine patients treated preoperatively. One very narrow stenosis could not be passed. Dysfunction occurred in two long stenoses after 5 days with reocclusion 2 and 6 weeks, respectively, after stent placement. A cost reduction of 19.7% was observed as a result of shorter hospitalization and a lower complication rate. In patients with colon cancer in the preoperative treatment group, the cost reduction increased to 28.8%. CONCLUSION: Metallic stent placement in patients with acute colonic obstruction was a minimally invasive and cost-effective preoperative procedure that allowed single-stage surgery in most cases. Stent placement for palliation should be limited to patient with special indications.

Focal hepatic lesion detection: comparison of four T2-weighted MR imaging pulse sequences.

Kanematsu M. Hoshi H. Murakami T. Inaba Y. Hori M. Nandate Y. Yokoyama R. Nakamura H.
Department of Radiology, Gifu University School of Medicine, Japan.
PURPOSE: To evaluate T2-weighted magnetic resonance (MR) imaging with conventional spin-echo, breath-hold fast spin-echo, respiratory-triggered fast spin-echo, and breath-hold multishot spin-echo echo-planar sequences for detection of focal hepatic lesions. MATERIALS AND METHODS: T2-weighted MR images obtained with the four sequences in 56 patients with 107 solid and 124 nonsolid lesions were retrospectively analyzed. Image review was conducted on a liver segment-by-segment basis; a total of 408 liver segments were reviewed separately and independently for solid and nonsolid lesions by three radiologists. Diagnostic accuracy was evaluated with receiver operating characteristic analysis. RESULTS: Lesion-to-liver contrast-to-noise ratio was highest with multishot echo-planar images of both solid and nonsolid lesions. Diagnostic accuracy for solid lesions was statistically significantly better with conventional spin-echo images than with any other type of image (P < .0001). Diagnostic accuracy for nonsolid lesions was statistically significantly better with respiratory-triggered fast spin-echo images than with any other type of image (P < .0001). Image quality was best with breath-hold fast spin-echo images. CONCLUSION: Conventional spin-echo MR imaging should not be replaced with breath-hold fast spin-echo or multishot spin-echo echo-planar imaging, despite the shorter acquisition times that are possible with the latter two sequences.

Segment 4 (the quadrate lobe): a barometer of cirrhotic liver disease at US.

Lafortune M. Matricardi L. Denys A. Favret M. Dery R. Pomier-Layrargues G.
Department of Radiology, Hopital Saint-Luc, Montreal, Quebec, Canada.
PURPOSE: To evaluate the dimensions of segment 4 of the liver in patients with cirrhosis by using ultrasonography (US). MATERIALS AND METHODS: The transverse diameter of segment 4 was measured in 125 control subjects without liver disease and 167 patients with cirrhosis. The size of segment 4 was measured on oblique subcostal US scans obtained between the left wall of the gallbladder (or the main fissure after cholecystectomy) and the ascending or umbilical portion of the left portal vein at the point where it gives rise to the branch to segment 4. RESULTS: In the control subject group, the mean diameter of segment 4 was 43 mm +/- 8 (standard deviation). In the patient group, the mean diameter of segment 4 was 28 mm +/- 9. The cause or severity of cirrhosis had no influence on the size of segment 4. CONCLUSION: A decreased diameter of segment 4 may be a helpful adjunct sign of cirrhosis in the US investigation of chronic liver disease.

Superparamagnetic iron oxide particles (SH U 555 A): evaluation of efficacy in three doses for hepatic MR imaging.

Shamsi K. Balzer T. Saini S. Ros PR. Nelson RC. Carter EC. Tollerfield S. Niendorf HP.
Department of Magnetic Resonance and Ultrasound Contrast Media, Schering, Berlin, Germany.
PURPOSE: To evaluate the efficacy of SH U 555 A in three doses for magnetic resonance (MR) imaging in the liver and to establish the best postinjection time point for liver MR imaging. MATERIALS AND METHODS: Pre- and postcontrast image sets obtained in 169 patients after injection of SH U 555 A (randomly, 4, 8, or 16 mumol of iron per kilogram of body weight). Three blinded readers evaluated the precontrast and 10- and 40-minute postcontrast MR images of 54, 58, and 57 patients, respectively. RESULTS: Statistically significant differences were observed in diagnostic confidence between images obtained with a dose of 4 or 16 mumol Fe/kg (P = .011) and in good or excellent improvement, respectively, in delineation of lesions on 10-minute postcontrast images (P = .001). No apparent differences in the efficacy evaluation were seen between the 10- and 40-minute postcontrast imaging time points. CONCLUSION: There was a dose-dependent postcontrast improvement in evaluated efficacy parameters (diagnostic confidence, visual evaluations) after injection of SH U 555 A. Accumulation phase imaging could begin as early as 10 minutes after administration.

Pancreatic cancer: value of dual-phase helical CT in assessing resectability.

Diehl SJ. Lehmann KJ. Sadick M. Lachmann R. Georgi M.
Institute for Clinical Radiology, Klinikum der Stadt Mannheim, Faculty of Clinical Medicine Mannheim, University of Heidelberg, Germany.
PURPOSE: To evaluate the use of dual-phase helical computed tomography (CT) (with or without CT angiography) to assess resectability in patients suspected to have pancreatic cancer. MATERIALS AND METHODS: Tumor resectability was prospectively evaluated in 89 patients who later underwent surgery for suspected pancreatic cancer. Helical CT scans were obtained in the vascular phase and a phase of maximal hepatic enhancement. CT angiograms were produced with multiprojection volume reconstruction and maximum-intensity projection. CT results were correlated with surgical and histopathologic results. RESULTS: Helical CT allowed detection of pancreatic cancer in 74 of 76 cases (97%). There were six false-positive results (positive predictive value, 92%). For prediction of irresectability, helical CT had an accuracy of 91%, negative predictive value of 79%, and sensitivity of 91%. Helical CT allowed detection of liver metastases in 21 of 28 cases (75%), nodal involvement in 13 of 24 cases (54%), and vascular invasion in 35 of 40 cases (88%). CT angiography demonstrated 30 of the 35 cases of vascular invasion detected with helical CT (86%). CONCLUSION: Use of dual-phase helical CT improves prediction of resectability in patients with pancreatic cancer. CT angiography cannot show all of the findings seen on helical scans.

Optimal MR cholangiopancreatographic sequence and its clinical application.

Irie H. Honda H. Tajima T. Kuroiwa T. Yoshimitsu K. Makisumi K. Masuda K.
Department of Radiology, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
PURPOSE: To determine the appropriate acquisition parameters for magnetic resonance cholangiopancreatography (MRCP) with a half-Fourier rapid acquisition with relaxation enhancement (RARE) sequence; to determine the optimal MRCP technique by comparing half-Fourier RARE, steady-state free precession (SSFP) two-dimensional (2D) fast spin-echo (SE), and three-dimensional (3D) fast SE sequences; and to clarify the usefulness and limitations of MRCP in diagnosing pancreatic abnormalities. MATERIALS AND METHODS: Half-Fourier RARE MRCP images with varying parameters were compared by using a phantom. Duct conspicuity and contrast-to-noise ratios (C/Ns) were compared for the four MRCP techniques in a phantom and healthy volunteers. The optimal MRCP technique was used to study healthy volunteers and clinical cases. Receiver operating characteristic (ROC) curves were created for data analysis. RESULTS: A 5-mm-thick section without intersection gap was appropriate for half-Fourier RARE MRCP. Only half-Fourier RARE MRCP could depict a 1-mm duct. C/N was the highest with half-Fourier RARE, followed by 3D fast SE, 2D fast SE, and SSFP sequences. ROC curve analysis revealed no interobserver differences, and the area under the curve for detection of strictures of the main pancreatic duct was as high as 0.89. CONCLUSION: Half-Fourier RARE MRCP has the highest contrast and spatial resolution among the four techniques studied and may play an important role in diagnosing pancreatic abnormalities.

Alendronate-induced esophagitis: case report of a recently recognized form of severe esophagitis with esophageal stricture--radiographic features.

Ryan JM. Kelsey P. Ryan BM. Mueller PR.
Department of Radiology, Massachusetts General Hospital, Boston, USA.
Alendronate sodium, an aminobiphosphonate used primarily to treat osteoporosis in postmenopausal women, is known to cause esophagitis. A 71-year-old woman experienced severe, acute esophagitis and severe stricture of the esophagus due to oral alendronate therapy. Unlike in previous cases, she had taken alendronate for 10 months before the onset of complications and the stricture proved resistant to dilation.

Prospective sonographic evaluation of interleukin-2-induced changes in the gallbladder.

Premkumar A. Walworth CM. Vogel S. Daryanani KD. Venzon DJ. Kovacs JA. Feuerstein IM.
Department of Diagnostic Radiology, Warren Grant Magnuson Clinical Center, National Institutes of Health, Bethesda, MD 20892-1182, USA.
PURPOSE: To describe the changes in the gallbladder induced by interleukin-2 (IL-2) therapy and to correlate the findings with the clinical course. MATERIALS AND METHODS: Twenty-five men with human immunodeficiency virus (HIV) infection were examined prospectively with right upper quadrant ultrasonography (US) before and after receiving IL-2 therapy. Four patients also underwent US after a second course of IL-2. The gallbladder was evaluated for wall thickening, echotexture, and intramural and pericholecystic fluid. Correlation was made between the clinical signs and symptoms, IL-2 dose, CD4 cell count, and the US appearance of the gallbladder. RESULTS: There was significant correlation between symptoms of right upper quadrant pain during IL-2 therapy and US abnormalities of the gallbladder, including an increase in wall thickening (P = .012) and the development of intramural (P = .015) and pericholecystic (P = .006) fluid. More severe abnormalities were seen with higher IL-2 doses. All symptoms resolved with cessation of IL-2 therapy. In patients who underwent repeat US, the gallbladder reverted to a normal appearance. No correlation was found between the CD4 cell count and the development of symptoms or the US appearance of the gallbladder. CONCLUSION: IL-2-induced changes resolve rapidly with cessation of therapy, and no surgical intervention is needed. These changes can be avoided or reduced by decreasing the IL-2 dose during subsequent cycles.

Malignant colorectal obstruction: treatment with a flexible covered stent.

Choo IW. Do YS. Suh SW. Chun HK. Choo SW. Park HS. Kang SK. Kim SK.
Department of Radiology, College of Medicine, Sung Kyun Kwan University, Samsung Medical Center, Kangnam-ku, Seoul, Korea.
PURPOSE: To evaluate the usefulness of flexible covered stents for treatment of acute colorectal obstruction secondary to malignant colorectal carcinoma. MATERIALS AND METHODS: Twenty patients with acute colorectal obstruction secondary to malignant colorectal carcinoma were treated by means of intubation of a flexible stent with fluoroscopic guidance with occasional endoscopic assistance. Two types of stents were placed (type 1, completely covered, type 2, two-thirds of proximal part uncovered). Of 15 patients with primary colorectal carcinoma, 12 underwent placement of a stent for presurgical decompression of colorectal obstruction; three, for palliative decompression. In three patients with rectosigmoid seeding from advanced gastric carcinoma and two patients with recurrent colonic carcinoma, stents were placed for palliative decompression. RESULTS: Stent placement was successful in 18 (90%) of 20 patients. Symptoms of obstruction resolved within 24 hours in 15 (75%) patients. Eight patients underwent elective single-stage surgery without complications 5-7 days after stent placement. Two patients underwent tumor resection and colostomy. In eight patients, stents provided palliative decompression of the colon. Type 1 stents migrated in four (50%) of eight patients; type 2 stents were used thereafter. CONCLUSION: Flexible stents effectively relieved acute colonic obstruction secondary to malignant rectosigmoid neoplasm. Stent placement allowed patients to undergo single-stage surgery in most cases and provided palliative decompression in cases of inoperable or disseminated disease.

Dynamic MR defecography with a superconducting, open-configuration MR system.

Year 1998
Schoenenberger AW. Debatin JF. Guldenschuh I. Hany TF. Steiner P. Krestin GP.
Institute of Diagnostic Radiology, University Hospital Zurich, Switzerland.
PURPOSE: To evaluate dynamic magnetic resonance (MR) defecography performed with a superconducting, open-configuration system in diagnosis of defecation disorders. MATERIALS AND METHODS: Five healthy volunteers and 15 patients with defecation disorders were studied with MR defecography performed with a superconducting, open-configuration system; the patients also underwent fluoroscopic defecography. Before MR imaging, the rectum was filled with 300 mL of mashed potatoes mixed with 1.5 mL of gadopentetate dimeglumine. T1-weighted gradient-echo images were acquired every 2 seconds in the midsagittal plane with the patient at rest, at maximal contraction of the anal sphincter, during straining, and during defecation. RESULTS: MR defecography permitted analysis of the anorectal angle, anal canal, puborectal muscle, and descent of the pelvic floor. Owing to the high signal intensity of the intraluminal contrast material, the rectal walls were well demonstrated on the MR images, permitting visualization of intussusception and rectocele. Concomitant demonstration of structures surrounding the anorectal canal was helpful in assessment of spastic pelvic floor syndrome and descending perineum syndrome. MR defecography was superior to fluoroscopic defecography and allowed detection of all clinically relevant pathologic conditions except for one. CONCLUSION: Dynamic MR defecography is an attractive alternative for evaluation of defecation disorders.

Esophageal varices: evaluation with transabdominal US.

Year 1998
Kishimoto R. Chen M. Ogawa H. Wakabayashi MN. Kogutt MS.
Department of Radiology, School of Medicine, Hokkaido University, Sapporo, Japan.
PURPOSE: To prospectively evaluate the clinical usefulness of transabdominal ultrasound (US) in the detection of esophageal varices. MATERIALS AND METHODS: Transabdominal US was performed in 47 patients (30 men, 17 women; age range, 18-75 years) with liver cirrhosis or idiopathic portal hypertension. The intraabdominal esophagus was demonstrated satisfactorily, and the findings were correlated with the presence of esophageal varices at endoscopy and angiography. The thickness of the anterior wall of the intraabdominal esophagus was measured and the irregularity of the wall surface documented. Blood flow signal in the esophageal wall also was evaluated with color Doppler and pulsed Doppler examinations. RESULTS: The mean thickness of the esophageal wall was 5.7 mm +/- 1.7 (standard deviation) in patients with esophageal varices and 3.6 mm +/- 0.96 in patients without varices. This difference was statistically significant (P < .001). Varices also caused irregular wall surfaces. Another specific finding was hepatofugal venous flow within the esophageal wall at Doppler examination. When an esophageal wall thickness of at least 5 mm or an irregular wall surface was used as a diagnostic criterion for esophageal varices, the sensitivity, specificity, and accuracy were 93%, 82%, and 89%, respectively. CONCLUSION: Transabdominal US can play a role in screening for esophageal varices. The intraabdominal esophagus should be observed during standard abdominal US in patients with chronic liver disease.

Tumor involvement in hepatic veins: comparison of MR imaging and US for preoperative assessment.

Year 1998
Hann LE. Schwartz LH. Panicek DM. Bach AM. Fong Y. Blumgart LH.
Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA.
PURPOSE: To compare use of magnetic resonance (MR) imaging and ultrasonography (US) for diagnosis of vascular involvement by tumor at the hepatic vein confluence. MATERIALS AND METHODS: Thirty-seven consecutive patients with tumors at the hepatic vein confluence were prospectively evaluated with spin-echo and gradient-echo MR imaging and gray-scale and Doppler US. Encasement, thrombosis, occlusion, and nonvisualization were considered to be evidence of vascular involvement. Imaging results were compared with surgical and pathologic examination findings in 27 patients who underwent resection. RESULTS: Sixteen hepatic veins (nine right, four middle, three left) were seen to be involved at surgery. Twelve of 16 involved veins were identified at MR imaging (75% sensitivity, 98% specificity, 92% positive predictive value, 94% negative predictive value). Thirteen of 16 involved veins were detected at US (81% sensitivity, 97% specificity, and 87% positive and 95% negative predictive values). There was one false-positive diagnosis of inferior vena cava involvement at both MR imaging and US. Ten patients had unresectable disease. One patient had motion artifact on MR images; in the remaining nine patients, MR imaging and US yielded identical findings at 26 of 27 hepatic vein sites. CONCLUSION: MR imaging and US provide comparable results for assessment of hepatic vein involvement by tumor.

Breath-hold MR cholangiography with snapshot techniques: prospective comparison with endoscopic retrograde cholangiography.

Year 1998
Holzknecht N. Gauger J. Sackmann M. Thoeni RF. Schurig J. Holl J. Weinzierl M. Helmberger T. Paumgartner G. Reiser M.
Department of Diagnostic Radiology, Ludwig Maximilian University, Munich, Germany.
PURPOSE: To compare findings with magnetic resonance (MR) cholangiography with rapid acquisition with relaxation enhancement (RARE) and half-Fourier acquisition with single-shot turbo spin-echo (hereafter, half Fourier RARE) snapshot imaging techniques to those with endoscopic retrograde cholangiography (ERC). MATERIALS AND METHODS: Heavily T2-weighted thick-section (RARE) and thin-section (half-Fourier RARE) MR cholangiography were performed prospectively, on a 1.5-T imager, in the biliary tree of 61 consecutive patients before ERC. Findings at ERC were considered the standard of reference. The radiologist and endoscopist were blinded to each other's report. On- and off-site MR cholangiographic readings were performed to detect stones (n = 24), biliary dilatation (n = 34), or stenosis (n = 36). RESULTS: The sensitivity and specificity of MR cholangiography, respectively, calculated on a lesion-by-lesion basis, were 92.3% and 95.8% for cholangiolithiasis, 94.1% and 92.6% for duct dilatation, and 88.8% and 84.0% for stenosis. With snapshot MR cholangiography, on a patient-by-patient basis, differentiation between normal (n = 15) and abnormal (n = 46) results yielded a sensitivity of 92.4%, a specificity of 83.4%, and a positive predictive value of 95.6%. Pitfalls were caused by flow artifacts, compression by vessels, and low contrast between calculi and surrounding parenchyma. CONCLUSION: Snapshot MR cholangiography allowed noninvasive, accurate detection of biliary stones, strictures, and dilatation similar to that with ERC. Discrepancies regarding low-grade dilatation and strictures had no clinical relevance at retrospective review.

Percutaneous transjejunal biliary intervention: 10-year experience with access via Roux-en-Y loops.

Year 1998
McPherson SJ. Gibson RN. Collier NA. Speer TG. Sherson ND.
Department of Radiology, University of Melbourne, Royal Melbourne Hospital, Parkville, Victoria, Australia.
PURPOSE: To assess the safety and efficacy of percutaneous retrograde transjejunal cholangiography and biliary intervention for benign and malignant disease. MATERIALS AND METHODS: The clinical and radiographic records of 43 patients (31 with benign and 12 with malignant disease) who had undergone percutaneous retrograde transjejunal biliary intervention over a 10-year period at a single institution were reviewed. One hundred eighty-one procedures were performed via a fixed Roux-en-Y loop and 15 via an unfixed loop. RESULTS: Percutaneous retrograde transjejunal cholangiography was attempted on 196 occasions (143 for benign and 53 for malignant disease). Primary successful access was obtained in 181 (92.3%). Adjunctive percutaneous transhepatic cholangiography improved successful access in an additional seven procedures, to 188 (95.9%). Interventions included stricture dilation, stone extraction, stent insertion, and brachytherapy. The mean number of biliary interventions and the mean interval between them were 3.1 interventions and 5.9 months in the benign group and 3.6 interventions and 3.8 months in the malignant group. The complication rate was 4.1%, with no deaths or episodes of biliary sepsis. CONCLUSION: Percutaneous transjejunal biliary access allows repeated interventions over many years with a low morbidity. Routine superficial fixation of Roux-en-Y loops is recommended for all biliary-enteric anastomoses to allow use of this safe and effective approach for any subsequent biliary intervention.

Insulinoma and islet cell hyperplasia: value of the calcium intraarterial stimulation test when findings of other preoperative studies are negative.

Year 1998
Pereira PL. Roche AJ. Maier GW. Huppert PE. Dammann F. Farnsworth CT. Duda SH. Claussen CD.
Department of Diagnostic Radiology, Eberhard-Karls-University, Tubingen, Germany.
PURPOSE: To evaluate the efficacy of the intraarterial calcium test in localizing sources of hyperinsulinism that remain undetectable at preoperative morphologic studies. MATERIALS AND METHODS: Twenty-four patients with clinically proved endogenous hyperinsulinism due to tumorous insulin production were prospectively enrolled. They underwent ultrasound (US), computed tomography, magnetic resonance imaging, endoscopic US, abdominal arteriography, and a calcium test, in which insulin concentrations were measured in hepatic venous blood after selective intraarterial calcium stimulation. The results of the calcium test in seven patients (five women, two men; age range, 30-66 years; mean age, 47 years) with negative findings of morphologic studies are described. RESULTS: Six solitary insulinomas (mean diameter, 0.73 cm) and one nodular hyperplasia were diagnosed after surgery. In all seven cases, calcium test findings allowed accurate localization of the pathologic source of insulin secretion. In three of these seven cases, results of arterial calcium stimulation with hepatic venous sampling (ASVS) affected intraoperative management. An increase in insulin concentration after stimulation in the hepatic artery was not observed, making hepatic metastases unlikely. CONCLUSION: ASVS, which is procedurally simpler than transhepatic pancreatic venous sampling, is effective for localizing sources of hyperinsulinism not detected with preoperative morphologic studies.

Intussusception in children: reduction with repeated, delayed air enema.

Year 1998
Gorenstein A. Raucher A. Serour F. Witzling M. Katz R.
Division of Pediatric Surgery, Edith Wolfson Medical Center, Holon, Israel.
PURPOSE: To evaluate the efficacy of pneumatic reduction of intussusception with an emphasis on repeated, delayed trials. MATERIALS AND METHODS: Seventy-one patients with intussusception were treated with air enemas. Before 1993, one trial of air reduction was performed; since 1993, up to three trials of air reduction were performed. The patients were categorized according to the duration of signs and symptoms: less than 12 hours (group A), 12-24 hours (group B), and longer than 24 hours (group C). RESULTS: The success rate for air reduction was 83% overall (59 of 71 patients), 89% in group A (25 of 28 patients), 83% in group B (20 of 24 patients), and 74% in group C (14 of 19 patients). The success rate was 70% (19 of 27 patients) before 1993 and 91% (40 of 44 patients) since 1993 (P < .05). When patients in whom air reduction was successful were compared with patients in whom it was unsuccessful, there was a statistically significant difference in radiographic signs of intestinal obstruction and duration of signs and symptoms but no important difference in age or rectal bleeding. There were no episodes of complications. CONCLUSION: Repeated, delayed pneumatic reduction of intussusception improves the outcome.

Cystic fibrosis: CT findings of colonic disease.

Year 1998
Pickhardt PJ. Yagan N. Siegel MJ. Balfe DM. Rothbaum RJ.
Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, MO 63110, USA.
PURPOSE: To determine the computed tomographic (CT) findings that are indicative of bowel disease in patients with cystic fibrosis. MATERIALS AND METHODS: CT scans in patients with cystic fibrosis were retrospectively reviewed for evidence of colonic abnormalities, including wall thickening, mural striation, fatty proliferation of the mesentery, and soft-tissue infiltration of pericolonic fat. RESULTS: Ten patients with colonic abnormalities on CT scans (case patients) and 16 patients with normal CT results (cohort patients) were identified. Colonic abnormalities in case patients included wall thickening (mean thickness, 6.4 mm) and mesenteric infiltration in all, increased pericolonic fat in six, and mural striation in five. The right colon was involved in all case patients; contiguous extension involved the transverse colon in five, the descending colon in two, and all segments in one. Wall thickness in cohort patients was less than 2 mm. Eight case patients had abdominal pain; one had bloody diarrhea. Histopathologic examination results included nonspecific mucosal inflammation in four case patients, wall edema in one, and no abnormality in one. No patient had identifiable infectious colitis, colonic stricture, bowel obstruction, fibrosis, or Crohn disease. Mean dose of pancreatic enzyme replacement was similar in both groups. CONCLUSION: Proximal colonic wall thickening without stricture, pericolonic fat proliferation, and mesenteric infiltration are CT findings of colonic disease associated with cystic fibrosis.

Staging of primary colorectal carcinomas with fluorine-18 fluorodeoxyglucose whole-body PET: correlation with histopathologic and CT findings.

Year 1998
Abdel-Nabi H. Doerr RJ. Lamonica DM. Cronin VR. Galantowicz PJ. Carbone GM. Spaulding MB.
Department of Nuclear Medicine, State University of New York at Buffalo, NY 14214, USA.
PURPOSE: To evaluate the diagnostic usefulness of positron emission tomography (PET) with fluorine-18 fluorodeoxyglucose (FDG) in patients with primary colorectal carcinomas. MATERIALS AND METHODS: Forty-eight patients with biopsy-proved (n = 44) or high clinical suspicion for (n = 4) colorectal cancer underwent whole-body PET after intravenous administration of 10 mCi (370 MBq) of FDG. FDG PET results were correlated with computed tomographic (CT), surgical, and histopathologic findings. RESULTS: PET depicted all known intraluminal carcinomas in 37 patients (including two in situ carcinomas) (sensitivity, 100%), but findings were false-positive in four of seven patients without cancer (three with inflammatory bowel conditions, one who had undergone polypectomy). Specificity was 43% (three of seven patients); positive predictive value, 90% (37 of 41 patients); and negative predictive value, 100% (three of three patients). No FDG accumulation was noted in 35 hyperplastic polyps. FDG PET depicted lymph node metastases in four of 14 patients (sensitivity, 29%). Results were similar to those obtained with CT (true-positive, two of seven patients [sensitivity, 29%]; true-negative, 22 of 26 patients [specificity, 85%]). FDG PET depicted liver metastases in seven of eight patients and was superior to CT, which depicted liver metastases in three patients (sensitivity of 88% and 38%, respectively). FDG PET and CT, respectively, correctly depicted the absence of liver metastases in 35 and 32 patients (specificity, 100% and 97%; negative predictive value, 97% and 86%). CONCLUSION: FDG PET has a high sensitivity and specificity for detection of colorectal carcinomas (primary and liver metastases) and appears to be superior to CT in the staging of primary colorectal carcinoma.

Sonographic comparison of intraarterial CO2 and helium microbubbles for detection of hepatocellular carcinoma: preliminary observations.

Year 1998
Nishiharu T. Yamashita Y. Arakawa A. Sumi S. Mitsuzaki K. Matsukawa T. Takahashi M.
Department of Radiology, Kumamoto University Hospital, Japan.
PURPOSE: To evaluate the usefulness of helium gas microbubbles in the detection of small hepatocellular carcinoma (HCC) lesions relative to that of CO2 microbubbles. MATERIALS AND METHODS: Ultrasonography (US) enhanced with both CO2 microbubbles and helium microbubbles was performed in 15 patients. CO2 microbubbles were injected into the proper hepatic artery under US observation. Next, helium microbubbles were injected. Duration and degree of enhancement with the two types of microbubbles were compared. Ten minutes after helium injection, the whole liver was examined with US to detect additional tumors. When new lesions were detected, biopsy was performed. RESULTS: Duration of enhancement with the helium microbubbles (mean, 37.2 minutes) was significantly longer than that with the CO2 microbubbles (mean, 3.6 minutes; P < .001). The degree of enhancement with helium was greater than that with CO2. Thirteen additional lesions were detected after injection of helium gas. All these lesions proved to be HCC at biopsy. CONCLUSION: The duration of enhancement is significantly longer with helium than with CO2 microbubbles. Therefore, helium microbubbles can be used for examination of the whole liver for detection of additional tumors.

Pneumatosis intestinalis: a review.

Year 1998
Pear BL.
Department of Radiology, University of Colorado Health Sciences Center, Denver, USA.
This review illustrates the changing paradigms in the understanding of the pathogenesis of pneumatosis intestinalis. Although many theories have been evoked, pragmatically there appear to be four major clinical and diagnostic imaging considerations. The most common and most emergent life-threatening cause of intramural bowel gas is the result of bowel necrosis due to bowel ischemia, infarction, necrotizing enterocolitis, neutropenic colitis, volvulus, and sepsis. In the stomach, intramural gas can be caused by emphysematous gastritis or ingestion of caustic agents. These situations represent surgical emergencies. Pneumatosis is found secondary to mucosal disruption presumably due to over-distention from peptic ulcer, pyloric stenosis, annular pancreas, and even to more distal obstruction. Disruption can also be caused by ulceration, erosions, or trauma, including the trauma of child abuse. Disruption can also be iatrogenic from intracatheter jejunal feeding tubes, stent perforation, sclerotherapy, or surgical or endoscopic trauma. In these cases, the gas may be focal or linear. Treatment depends on the extent of the disruption and the underlying cause. A more subtle form of mucosal disruption may occur due to mucosal erosions and also to defects in intestinal crypts secondary to acute and subclinical enteritides that allow intraluminal bacterial gas under pressure to percolate into the bowel wall layers, particularly the submucosa (29). Pneumatosis, often linear or cystic in appearance, is seen with increased frequency in patients who are immunocompromised because of steroids, chemotherapy, radiation therapy, or AIDS. In these cases, the pneumatosis may result from intraluminal bacterial gas entering the bowel wall due to increased mucosal permeability caused by defects in bowel wall lymphoid tissue. Clinical and imaging findings are important in the differentiation of this transient pneumatosis from fulminant life-threatening causes in this subset of patients. A pulmonary cause must still be considered in cases of chronic obstructive pulmonary disease, asthma, and cystic fibrosis. It can occur with barotrauma and after chest tube placement. It may relate to increased intrathoracic pressure associated with retching and vomiting. The possibility remains that occasionally the origin of pneumatosis intestinalis will remain cryptogenic--caused but unexplained.

Half-Fourier RARE MR cholangiopancreatography: experience in 300 subjects.

Year 1998
Fulcher AS. Turner MA. Capps GW. Zfass AM. Baker KM.
Department of Radiology, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298-0615, USA.
PURPOSE: To determine prospectively the clinical applications and diagnostic accuracy of half-Fourier rapid acquisition with relaxation enhancement (RARE) magnetic resonance (MR) cholangiopancreatography (MRCP) in a large patient population. MATERIALS AND METHODS: Breath-hold, heavily T2-weighted half-Fourier RARE MRCP was performed in 265 patients with suspected pancreaticobiliary disease and in 35 control patients without symptoms or signs referrable to the biliary tract or pancreatic duct. MRCP findings were correlated with those at direct cholangiography, pathologic examination, cross-sectional imaging, and clinical follow-up. RESULTS: Diagnostic MRCP examinations were obtained in 299 (99.7%) subjects. MRCP yielded an accuracy of 100% in determining the presence of pancreaticobiliary disease, the presence and level of biliary obstruction, and obstruction due to bile duct calculi. The accuracy of MRCP and MR imaging in determining the presence and level of malignant obstruction was 98.2%. MRCP obviated endoscopic retrograde cholangiopancreatography (ERCP) by excluding choledocholithiasis in patients with acute pancreatitis (n = 13) and nonspecific abdominal pain (n = 82). In patients with sclerosing cholangitis and acquired immunodeficiency syndrome cholangiopathy, MRCP depicted the biliary tract as clearly as did ERCP (n = 9). After failed ERCP, MRCP delineated the pancreaticobiliary tract and helped determine therapeutic options (n = 27). CONCLUSION: Half-Fourier RARE MRCP enables accurate evaluation of pancreaticobiliary disease and obviates ERCP in some patients.

Biliary tract carcinoma complicating primary sclerosing cholangitis: evaluation with CT, cholangiography, US, and MR imaging.

Year 1998
Campbell WL. Ferris JV. Holbert BL. Thaete FL. Baron RL.
Department of Radiology, University of Pittsburgh Medical Center, PA 15213, USA.
PURPOSE: To assess the value of computed tomography (CT), cholangiography, ultrasonography (US), and magnetic resonance (MR) imaging in the demonstration of biliary tract carcinoma complicating primary sclerosing cholangitis (PSC). MATERIALS AND METHODS: Thirty patients were studied who had PSC and biliary tract carcinoma. Twenty-six patients had cholangiocarcinoma, and four had gallbladder carcinoma. Sixty-four CT scans, 41 cholangiograms, 40 US studies, and seven MR studies were reviewed retrospectively for evidence of tumor and PSC. Imaging results were correlated with pathologic findings from whole liver specimens and biopsies. Presence of mass was rated as definite, probable, possible, or doubtful or absent. RESULTS: On CT scans, cholangiocarcinomas produced hypoattenuating masses in 17 of 23 cases, delayed contrast enhancement in six of 12, progressive biliary dilatation in five of 15, and thickened bile duct wall in two of 23. On cholangiograms, dominant strictures were present in 18 of 21 cases of cholangiocarcinoma; 13 were malignant, and five were benign. Cholangiocarcinoma formed polypoid bile duct masses in two of 21 cases. Biliary dilatation was caused by cholangiocarcinoma in 10 of 12 cases and by benign stricture in two. Gallbladder carcinomas demonstrated masses on CT scans, cholangiograms, and US images, and wall thickening on CT and US images. Overall, definite or probable tumor was demonstrated in 25 of 30 patients (83%). CONCLUSION: Most biliary tract carcinomas complicating PSC can be demonstrated on imaging studies.

Hepatic hemangioma: quantitative color power US angiography--facts and fallacies.

Year 1998
Young LK. Yang WT. Chan KW. Metreweli C.
Department of Diagnostic Radiology and Organ Imaging, Chinese University of Hong Kong, Prince of Wales Hospital, Yuen Chau Kok, Shatin, China.
PURPOSE: To explore the origin of signals detected with color power ultrasound (US) angiography (CPA) and evaluate a semiquantitative method to assess signals in hepatic hemangiomas. MATERIALS AND METHODS: Twenty-four adult patients with 27 hepatic hemangiomas (< 2 cm in diameter) and five patients with five hyperechoic hepatic metastases underwent CPA and conventional color Doppler US in this prospective study. A sponge phantom was studied to determine whether the origin of CPA signals was related to architecture. The mean number of signals and the signal density in each lesion were scored. RESULTS: A "diffuse blush" was seen in all capillary hemangiomas at CPA, whereas no signal was seen at color Doppler US. The sponge phantom test produced a CPA appearance similar to that of capillary hemangiomas. Quantitative analysis of CPA images of hepatic hemangiomas showed a mean of 16.1 signals per cubic centimeter and a mean signal area of 25%. Hyperechoic avascular hepatic metastases resulted in CPA images similar to those of hepatic hemangiomas, with no quantitative difference in signal count, despite a mild qualitative difference at CPA. CONCLUSION: CPA signals in hepatic hemangiomas appear to be related more to architecture than to true capillary flow. There is a qualitative difference in the strength of the blush at CPA between hepatic hemangiomas and metastases, which may be the only possible differentiating factor.

Detection of mass lesions with MR colonography: preliminary report.

Year 1998
Luboldt W. Steiner P. Bauerfeind P. Pelkonen P. Debatin JF.
Institute of Diagnostic Radiology, University Hospital Zurich, Switzerland.
PURPOSE: To evaluate the performance of magnetic resonance (MR) colonography in the detection of colorectal mass lesions. MATERIALS AND METHODS: Twenty-three patients underwent MR colonography preceding colonoscopy. The colon was filled with a gadolinium-water mixture (1:100) with MR imaging guidance, and the patient was imaged prone and supine with a breath-hold three-dimensional spoiled gradient-recalled sequence. In addition, two-dimensional spoiled gradient-recalled images were acquired before and after intravenous administration of gadopentetate dimeglumine. Images were interactively analyzed on the basis of multiplanar reconstruction by two radiologists. For regions that were not conclusively assessable with multiplanar reconstruction, virtual intraluminal endoscopic images of the colon were reconstructed. MR findings were correlated with colonoscopic results. RESULTS: Two patients were excluded from the analysis. Findings in eight of 11 patients were correctly assessed as normal and in six of 10 as mass-positive. In the four patients with false-negative findings, one had two 8-mm polyps and the other three had polyps smaller than 5 mm. All nine mass lesions larger than 10 mm, as well as four of the 10 polyps ranging between 5 and 10 mm, were detected, but all polyps smaller than 5 mm were missed. In contrast to the polyps less than 5 mm, the four missed polyps (5-10 mm) could be identified retrospectively on virtual intraluminal endoscopic images. Contrast enhancement was documented in 13 polyps. CONCLUSION: Three-dimensional MR colonography provided virtual colonoscopic viewing and helped detection of colonic polyps.

Pseudolesions at T1-weighted gradient-echo imaging after administration of superparamagnetic iron oxide: comparison with portal perfusion abnormalities at CT during arterial portography.

Year 1998
Scharf J. Hoffmann V. Lehnert T. Anselm H. Richter GM. Kauffmann GW.
Department of Radiology, University of Heidelberg Medical School, Germany.
PURPOSE: To compare specific findings at T1-weighted gradient-echo (GRE) magnetic resonance (MR) imaging performed after administration of superparamagnetic iron oxide (SPIO) with nontumorous regional portal perfusion abnormalities seen at computed tomography (CT) during arterial portography (CTAP). MATERIALS AND METHODS: The results of CTAP, MR imaging, and surgery were compared in 19 patients with liver metastases and five with benign liver tumors. MR imaging was performed by using turbo spin-echo (SE) sequences and a GRE sequence before and after infusion of SPIO. RESULTS: At CTAP, 34 nontumorous portal perfusion defects ("straight line sign," pseudolesions) were seen. After intravenous administration of SPIO, 18 nontumorous signal intensity differences were seen on T1-weighted GRE images in corresponding locations. No corresponding nontumorous signal intensity differences were seen on unenhanced MR images. The mean signal-to-noise ratio on the SPIO-enhanced GRE images was reduced from 26.3 to 16.6 in the areas of nontumorous signal intensity differences, whereas that in areas of normal portal perfusion (normal CTAP findings) was reduced to 10.2. CONCLUSION: Impaired portal perfusion decreased the uptake of SPIO in histopathologically normal regions of liver parenchyma. Resultant differences in signal intensity were better visualized on GRE than on turbo SE images.

Recurrent gastrointestinal bleeding: use of thrombolysis with anticoagulation in diagnosis.

Year 1998
Malden ES. Hicks ME. Royal HD. Aliperti G. Allen BT. Picus D.
Department of Vascular and Interventional Radiology, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, MO 63110, USA.
PURPOSE: To determine the safety and diagnostic accuracy of a provocative protocol with heparin and urokinase to induce bleeding and determine the source in patients with chronic gastrointestinal hemorrhage. MATERIALS AND METHODS: Nine patients had gastrointestinal bleeding from an indeterminate source and had negative results from esophagogastroduodenoscopy, colonoscopy, small-bowel examination, and angiography. Ten provocative bleeding studies were performed prospectively. Patients had no clinical evidence of bleeding within 2 days before the study. Intravenous administration of heparin and urokinase was performed systemically during a 4-hour period while scintigraphy was performed continuously. Mesenteric angiography was performed immediately in patients in whom substantial gastrointestinal bleeding was detected at scintigraphy. RESULTS: The provocative protocol was successful in inducing scintigraphically detectable hemorrhage in four (40%) studies within 4 hours. In two of these four studies, the source of hemorrhage was determined and treated with embolization or surgery. Three (30%) studies demonstrated scintigraphic evidence of hemorrhage only at delayed imaging (8-24 hours after initiation of the study). The remaining three (30%) studies did not show active bleeding. No complications occurred, including hemodynamic instability or uncontrollable decreases in hematocrit. CONCLUSION: Since this protocol with heparin and urokinase enabled determination of the bleeding source in only two of 10 studies, protocol modifications are necessary before this intervention is used widely.

Transjugular intrahepatic portosystemic shunt patency and the importance of stenosis location in the development of recurrent symptoms.

Year 1998
Saxon RS. Ross PL. Mendel-Hartvig J. Barton RE. Benner K. Flora K. Petersen BD. Lakin PC. Keller FS.
Dotter Interventional Institute, Oregon Health Sciences University, Portland, USA.
PURPOSE: To analyze in detail the location and types of stenosis and occlusion that occur after transjugular intrahepatic portosystemic shunt (TIPS) creation and to determine the relative contribution of these various types of TIPS malfunction to recurrent symptoms of variceal bleeding or ascites. MATERIALS AND METHODS: In 116 of 217 patients who underwent TIPS creation between June 1990 and July 1995, follow-up portal venography was performed at 6-month intervals and for symptoms of recurrent variceal bleeding or ascites. RESULTS: Cumulative primary venographic patency by means of Kaplan-Meier survival analysis was 55% at 6 months and 5% at 2 years. Secondary patency was 92% at 2 years. Stenosis or occlusion occurred in 63 of 116 patients (54%). In 20 patients (17%), acute shunt occlusions developed less than 30 days after TIPS creation; in 24 patients (21%), tract abnormalities were detected after 30 days; and in 19 patients (16%), hepatic vein stenoses were detected after 30 days. Abnormalities of the parenchymal tract were more often correlated with recurrent variceal bleeding or ascites than were hepatic vein stenoses (odds ratio, 3.6; P = .02). Ten of 14 patients (71%) with detected biliary fistulas to their TIPS had symptoms, and all patients with biliary fistulas had tract abnormalities. CONCLUSION: Tract stenoses and occlusions were the major cause of symptomatic shunt failure after TIPS creation. Substantial bile duct transections are often associated with tract abnormalities and recurrent symptoms. Although common, hepatic vein stenoses were rarely associated with recurrent symptoms in our patient population.

Progressive viral-induced cirrhosis: serial MR imaging findings and clinical correlation.

Year 1998
Ito K. Mitchell DG. Hann HW. Outwater EK. Kim Y. Fujita T. Okazaki H. Honjo K. Matsunaga N.
Department of Radiology, Thomas Jefferson University Hospital, Philadelphia, PA 19107, USA.
PURPOSE: To determine which magnetic resonance (MR) imaging findings of cirrhosis change as disease severity progresses. MATERIALS AND METHODS: Seventy-six abdominal MR imaging studies in 38 patients (two per patient) with Child-Pugh grade A cirrhosis were retrospectively reviewed. All patients were followed up clinically and with MR imaging for 12 months or longer. MR images were used to determine volume indexes of the spleen and of each liver segment, as well as changes in hepatic contour, iron or fat deposition, and presence of varices and collateral vessels. RESULTS: During follow-up in patients with progressive cirrhosis (n = 13), the volume indexes of the anterior, posterior, and medial segments of the liver decreased significantly (P = .011, .013, .002, respectively), and the number of varices and collateral vessels increased significantly (P = .018). In patients with stable cirrhosis (n = 25), the volume indexes of the spleen, caudate lobe, and lateral segment increased significantly (P = .032, .018, .003, respectively). The atrophic index was significantly greater in progressive cirrhosis than in stable cirrhosis (P = .009). CONCLUSION: Progressive atrophy of the right hepatic lobe and the medial segment correlated with progression of clinical severity of cirrhosis, whereas increasing size of the caudate lobe and the lateral segment correlated with stability.

Biliary stricture caused by blunt abdominal trauma: clinical and radiologic features in five patients.

Year 1998
Yoon KH. Ha HK. Kim MH. Seo DW. Kim CG. Bang SW. Jeong YK. Kim PN. Lee MG. Auh YH.
Department of Diagnostic Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
PURPOSE: To evaluate the clinical and radiologic features of biliary stricture after blunt abdominal trauma and to report the results of endoscopic stent placement. MATERIALS AND METHODS: Medical records and radiologic findings were reviewed in five patients with biliary stricture after blunt abdominal trauma. The level, length, and contour of the strictures were analyzed with endoscopic retrograde cholangiopancreatography (ERCP). Computed tomographic (CT) scans were also reviewed to determine the presence of biliary dilatation, configuration of the injured bile duct, and ancillary abdominal findings. Results from endoscopic stent placement were evaluated in all patients. RESULTS: Stricture occurred in the suprapancreatic portion of the common bile duct in four patients and in the intrapancreatic portion in one patient. At ERCP, the stricture contour was concentric and smooth in three patients, eccentric and smooth in one, and abruptly terminated in one. CT showed abrupt narrowing of the common bile duct with dilatation of the proximal portion in all patients. Endoscopic stent placement was successful in all patients. CONCLUSION: Patients with biliary stricture after blunt abdominal trauma exhibit a delayed onset of symptoms. A correct diagnosis may be difficult on the basis of findings from CT or ERCP alone without a clinical history or evidence of contusions at other sites.

Multiplanar CT pancreatography and distal cholangiography with minimum intensity projections.

Year 1998
Raptopoulos V. Prassopoulos P. Chuttani R. McNicholas MM. McKee JD. Kressel HY.
Department of Radiology, Beth Israel Deaconess Medical Center, Boston, MA, USA.
PURPOSE: To develop a technique of projectional computed tomographic (CT) cholangiopancreatography (CTCP). MATERIALS AND METHODS: Sixty-one patients underwent CT for suspected biliary or pancreatic abnormalities. The axial CT and CTCP techniques included spiral scanning during the portal venous phase and thick-slab minimum intensity projections. Visualization of pancreatic and extrahepatic bile ducts (divided in five duct segments per patient) was graded blindly on a scale of 1-5 by a consensus of two radiologists. Two hundred seventy-seven duct segments were used to compare axial CT and CTCP in the depiction of duct segments and dilatation; 109 segments were used to compare CTCP with ERCP. RESULTS: Fifty-six of 277 duct segments were not visualized on axial CT images; 15 segments were not visualized on CTCP images (P < .001). There was no statistically significant difference between the number of segments missed with ERCP and the number missed with CTCP: nine and three of 109 segments, respectively. Duct visualization was equal on axial CT and CTCP images in 35 of 109 duct segments and was superior on CTCP images in all but one of the remaining segments (P < .001). Duct visualization on CTCP images was equal to that on ERCP images in 35 segments, superior in nine, and significantly inferior in 66 (P < .001). CONCLUSION: CTCP improves CT depiction of pancreatic and bile ducts with a quality that approaches that of ERCP.

Hyperechoic liver nodules: characterization with proton fat-water chemical shift MR imaging.

Year 1998
Martin J. Puig J. Falco J. Donoso L. Rue M. Sentis M. Darnell A. Musulen E.
Department of Diagnostic Imaging, Unitat de Diagnostic per la Imatge d'Alta Tecnologia (UDIAT), Sabadell, Barcelona, Spain.
PURPOSE: To evaluate proton fat-water chemical shift fast low-angle shot magnetic resonance (MR) imaging for differentiation of fat-containing hyperechoic liver nodules from hyperechoic liver nodules without a fatty component. MATERIALS AND METHODS: T1-weighted fast low-angle shot fat-water chemical shift gradient-echo MR imaging was performed in 96 patients without cirrhosis with 138 hyperechoic liver nodules. In-phase and opposed-phase breath-hold images were acquired. The percentage of signal intensity variation between in-phase and opposed-phase images and the spleen-to-lesion contrast ratio were used to differentiate liver nodules. RESULTS: Chemical shift MR images showed fat in 15 (11%) hyperechoic nodules (two angiomyolipomas and 13 nodular fatty infiltrations of the liver). The mean percentage of signal intensity variation between in-phase and opposed-phase images was 156% (standard error, 43.5%) in nodules with fat and -0.16% (standard error, 0.96%) in nodules without fat (P = .003). Spleen-to-lesion contrast was similar on in- and opposed-phase images in lesions without fat (mean difference, -0.0107; standard error, 0.012), whereas the mean difference in fat-containing nodules was 0.805 (standard error, 0.225; P = .003). The area under the receiver operating characteristic curve was 0.97 for signal intensity variation. CONCLUSION: Hyperechogenicity in certain liver nodules is caused by fat. Chemical shift MR imaging allows accurate differentiation between these and other hyperechoic lesions with no fat component.

MR imaging of the liver: comparison between single-shot echo-planar and half-Fourier rapid acquisition with relaxation enhancement sequences.

Year 1998
Yamashita Y. Tang Y. Namimoto T. Mitsuzaki K. Takahashi M.
Department of Radiology, Kumamoto University School of Medicine, Japan.
PURPOSE: To evaluate single-shot T2-weighted magnetic resonance sequences and their role in clinical practice in patients with hepatic lesions. MATERIALS AND METHODS: Prospective comparison of echo-planar and half-Fourier rapid acquisition with relaxation enhancement (RARE) imaging was performed in 80 patients with focal hepatic lesions. Spin-echo (SE) single-shot echo-planar (echo times, 47 and 80 msec) and half-Fourier RARE (echo time, 59 msec) images were compared with turbo SE (repetition time msec/echo time msec = 3,200-7,600/90) images. Quantitative, qualitative, and receiver operating characteristic (ROC) analyses were performed. RESULTS: For liver, signal-to-noise ratios on half-Fourier RARE images were significantly higher than those on echo-planar images (P < .01). For cystic lesions, contrast on half-Fourier RARE and echo-planar images was slightly higher than that on turbo SE images. For solid lesions, contrast on echo-planar images was better than that on half-Fourier RARE or turbo SE images. Artifacts including ghosting, bowel motion, susceptibility difference, and chemical shift were negligible on half-Fourier RARE images in all patients, whereas susceptibility difference and chemical shift of various degrees were seen on all echo-planar images. On the basis of ROC analyses, tumor detection rates were significantly higher with half-Fourier RARE and turbo SE images than with echo-planar images (P < .01). CONCLUSION: Echo-planar images provide sufficient contrast to allow detection of both solid and cystic masses, but severe artifacts preclude routine use. Half-Fourier RARE images are free from artifacts (chemical shift and susceptibility) and diagnostic performance with them is similar to that with turbo SE images.

Septic metastatic endophthalmitis from Klebsiella pneumoniae liver abscess: CT and MR imaging characteristics--report of three cases.

Year 1998
Lee CC. Chen CY. Chen FH. Zimmerman RA. Hsiao HS.
Department of Diagnostic Radiology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, Republic of China.
Computed tomography (CT) and magnetic resonance (MR) imaging were performed in three diabetic patients with endophthalmitis and liver abscess secondary to Klebsiella pneumoniae infection. Ocular abnormalities included early uveoscleral thickening, fulminant exudative vitreous humor, and late phthisis bulbi. Characteristic imaging findings of endophthalmitis in diabetic patients with liver abscess should raise a high index of suspicion for K pneumoniae infection.

Malignant dysphagia: palliation with esophageal stents--long-term results in 100 patients.

Year 1998
Cwikiel W. Tranberg KG. Cwikiel M. Lillo-Gil R.
Department of Radiology, University Hospital, Lund, Sweden.
PURPOSE: To evaluate the long-term palliative effect of self-expanding nitinol esophageal stents in patients with malignant dysphagia. MATERIALS AND METHODS: One hundred patients with severe dysphagia secondary to malignant esophageal strictures were treated with self-expanding nitinol stents. The strictures were caused by squamous carcinoma (n = 43), adenocarcinoma (n = 28), anastomotic tumor recurrence (n = 14), and mediastinal tumor (n = 15). RESULTS: One hundred six stents were successfully positioned in 100 patients. Attempts to insert a second, coaxial stent were unsuccessful in two patients; a second stent was placed incorrectly in another patient. Statistically significant (P < .001) reduction of dysphagia was noted after expansion of the stents. Complications consisted of incomplete expansion secondary to stent twisting (n = 4), stent migration (n = 4), tumor ingrowth (n = 17), tumor overgrowth (n = 3), food impaction (n = 5), fracture of stent wires (n = 2), benign strictures at stent edges (n = 2), tumor bleeding (n = 3), and esophagorespiratory fistula (n = 5). The primary patency rate was 75% (77 of 102 stents); the secondary patency rate was 94% (96 of 102 stents). The survival time (mean, 6.2 months; range, 0.1-47 months) varied with the diagnosis. CONCLUSION: Placement of self-expanding nitinol stents is safe and has a good long-term palliative effect on dysphagia in patients with malignant esophageal strictures.