Elimination of artifactual accumulation of FDG in PET imaging of colorectal cancer.
Miraldi F. Vesselle H. Faulhaber PF. Adler LP. Leisure GP.
Department of Radiology, University Hospitals of Cleveland, School of Medicine, Case Western Reserve University, Ohio, USA.
BACKGROUND: Positron emission tomography (PET) with fluorine-18 labeled deoxyglucose (FDG) can detect tumor recurrences in surgical patients that are otherwise difficult to assess by CT, as well as distant metastases and small malignant nodes that are not identified by other imaging modalities. However, the evaluation of such malignancy is complicated by urinary and colonic concentrations of FDG. Methods and examples of the elimination of artifactual accumulation of FDG in PET imaging of the abdomen and pelvis are presented. METHODS: Elimination of artifactual accumulation requires patient preparation that begins with cleansing of the colon using an isosmotic solution taken the evening prior to examination. Approximately 500 MBq of F-18 FDG is intravenously administered upon arrival at the PET facility and then the patient is hydrated. After administration of furosemide, a Foley catheter with a drainage bag is placed and the patient is then scanned. Just prior to scanning over the pelvis, normal saline is delivered retrogradely into the urinary bladder. At the end of scanning, the patient voids and repeated pelvic images are obtained. RESULTS: These routines yield a clean scanning field. Lesions that will generally be missed because they are obscured by FDG accumulations along the colon or in the kidneys, ureters, or bladder are better visualized and identified with greater confidence. Artifacts that lead to misinterpretation also are reduced. CONCLUSION: Elimination of artifactual accumulation of FDG in the colon and urinary system is essential if primary cancer, associated adenopathy, or subtle recurrences are to be evaluated in FDG PET imaging of the abdomen and pelvis.
The use of the diagnostic radionuclide ascites scan to facilitate treatment decisions for hepatic hydrothorax.
Schuster DM. Mukundan S Jr. Small W. Fajman WA.
Grady Memorial Hospital, Department of Radiology, Emory University School of Medicine, Atlanta, Georgia, USA.
A 44-year-old man had an intractable right-sided pleural effusion due to cirrhosis, despite the absence of abdominal ascites. Instillation of Tc-99m macroaggregated serum albumin under CT guidance into the peritoneal space demonstrated transdiaphragmatic communication. This finding indicated the necessity for decompressing the portal system to treat the hydrothorax. The diagnostic radionuclide ascites scan may play an important role in the treatment approach to such patients.
Cold defect on indium leukocyte scanning of a hepatic abscess.
Burris GW. Gordon BM.
College of Medicine, Medical University of South Carolina, Charleston, USA.
Abdominal and, specifically, hepatic abscesses have always been difficult to diagnose clinically. The In-111 leukocyte scan has proven to be a valuable modality assisting in the diagnosis of an abscess. The authors present the case of a 64-year-old man who presented with vague clinical symptoms and inconclusive laboratory data for a hepatic abscess. Both the ultrasound and CT scan were nondiagnostic; however, a distinct cold defect within the liver on an In-111 leukocyte scan resulted in a liver biopsy, confirming the presence of an abscess. The potential causes of cold defects on In-111 WBC scanning and the limitations of this modality are discussed.
Abnormal radionuclide uptake in pseudomyxoma peritonei.
Chintapalli KN. Chopra S. Metter DF.
Department of Radiology, University of Texas Health Science Center at San Antonio 78284-7800, USA.
A case of pseudomyxoma peritonei with increased radionuclide uptake in the abdomen is described. The uptake of the radionuclide was confined to the omentum as confirmed by the CT study of the abdomen and pelvis. The mechanism of uptake and differential diagnosis are discussed.
The role of renal scintigraphy in the diagnosis and follow-up of unilateral ATN after complete bilateral distal ureteral obstruction as a complication of acute appendicitis.
Tiel-van Buul MM. Aronson DC. Groothoff JW. Van Baren R. Frenkel J. Van Royen EA.
Department of Nuclear Medicine, Academic Medical Center, University of Amsterdam, The Netherlands.
Acute anuria due to bilateral distal ureteral obstruction developed in two boys, ages 7 and 13, several days after appendectomy, without sonographic signs of hydronephrosis or hydroureters. Decompression was achieved after introduction of ureteric stents. This failed on the left side in one patient, and unilateral acute tubular necrosis (ATN) subsequently developed on that side. Although bilateral decompression was successful in the second patient, ATN had already developed on the left side. In both patients, Tc-99m MAG3 renal scintigraphy proved to be an important tool in diagnosing unilateral ATN and for evaluating the recovery from this rare complication.
Ischemic colitis: Tc-99m HMPAO leukocyte scintigraphy and correlative imaging.
Hyun H. Pai E. Blend MJ.
Department of Radiology, University of Illinois-Chicago Medical Center, 60612, USA.
A 62-year-old woman became progressively ill after aorto-bifemoral graft surgery. A Tc-99m hexamethylpropyleneamine oxime (HMPAO) leukocyte scan was performed because of fever and suspected graft infection. The anterior abdominal and pelvic views demonstrated marked uptake within the sigmoid colon. Follow-up studies, including CT scan and contrast intestinal x-rays, confirmed the presence of an abnormal sigmoid loop. Subsequent surgical resection and pathological examination of the sigmoid colon revealed ischemic changes. To our knowledge, detection of ischemic colitis using Tc-99m HMPAO labeled leukocytes has not been reported. Clinical and routine radiological findings of ischemic colitis are typically nonspecific and may result in delayed diagnosis that can lead to high mortality. Tc-99m HMPAO leukocyte scintigraphy may be helpful in the noninvasive diagnosis of ischemic injury to the colon, especially after aortic graft surgery.
BUN/creatinine ratios: aid to decision making about delayed imaging in Tc-99m red blood cell scans for gastrointestinal hemorrhage.
Lewis DH. Jacobson AF.
Division of Nuclear Medicine, Department of Veterans Affairs Puget Sound Health Care System, University of Washington School of Medicine, Seattle 98104, USA.
In patients with gastrointestinal hemorrhage, delayed or late scans with Tc-99m labeled red blood cells are readily performed and have prognostic impact when early images are negative. Nevertheless, there have been no indicators for the likelihood of detecting bleeding on such images. In a review of all gastrointestinal bleeding scans over an 8-year period, 73 patients had delayed images (> 3 hours) following early negative exams. For these patients, determinations of serum blood urea nitrogen (BUN) and creatinine (Cr) were evaluated as the BUN/Cr ratio and were compared against delayed scan findings and confirmed diagnoses. Patients with significant renal failure were excluded from analysis. There were 34 late positive (46%) and 39 late negative (54%) studies. Mean BUN/Cr was 26.5 and 20.0 in patients with late positive and late negative scans, respectively (p < 0.05). Occurrence of late positive scans was 38% (19/50) for BUN/Cr < 25.0 vs. 65% (15/23) for BUN/Cr > 25.0 (p < 0.05). Patients with early negative images and a BUN/Cr ratio of 25 or greater have a greater likelihood of a positive delayed image. Late imaging should be encouraged in patients with elevated BUN/Cr and early negative scintigraphy.
Acute cholecystitis in AIDS patients: correlation of Tc-99m hepatobiliary scintigraphy with histopathologic laboratory findings and CD4 counts.
Cacciarelli AG. Naddaf SY. el-Zeftawy HA. Aziz M. Omar WS. Kumar M. Atay S. Abujudeh H. Gillooley J. Abdel-Dayem HM.
Department of Medicine, St Vincent's Hospital and Medical Center of New York, Valhalla 10011, USA.
BACKGROUND: AIDS patients are susceptible to opportunistic gastrointestinal infections including ascending cholangitis and cholecystitis, especially if CD4 count is < 200. Incidence of acalculous cholecystitis has not been reported previously. PURPOSE: We aim to evaluate the incidence of acalculous cholecystitis in AIDS patients and to identify causative organisms and mortality rate following cholecystectomy. MATERIALS AND METHODS: We reviewed the files of 46 patients in order to meet the objectives of this study. RESULTS: CD4 counts were < 200 in 31 patients and > 200 in 15 patients. HIDA imaging was performed in 31 patients; in 8, the CD4 count was > 200 and all had calculous cholecystitis. The gallbladder was visualized in 3 patients for a sensitivity of 63% and no organisms were found in the gallbladder specimens. In 23 patients, the CD4 count was < 200; the gallbladder was visualized in 5 patients for a HIDA sensitivity of 78%; 16 (52%) had acalculous cholecystitis; and 15 had calculous cholecystitis. In acalculous cholecystitis, Cryptosporidium was found in six cases, cytomegalovirus (CMV) in six cases, and fungus, yeast, tuberculosis, and mycobacterium avium intracellular each in one case. The thirty day mortality rate was 18%; 5 of 28 who underwent open cholecystectomy died within 30 days, 4 of them with a CD4 count < 200. There was no mortality in the 26 patients who underwent laparoscopic cholecystectomy. CONCLUSION AND RECOMMENDATIONS: (1) Because of the high incidence of 52% of acalculous cholecystitis in AIDS patients with a CD4 count < 200, we recommend using intravenous cholecystokinin if the gallbladder is visualized on hepatobiliary scintigraphy in order to determine gallbladder ejection fraction and exclude acalculous cholecystitis. (2) Laparoscopic rather than open cholecystectomy should be the surgical procedure of choice in AIDS patients especially if the CD4 count is < 200.
The clinical utility of quantitative cholescintigraphy: the significance of gallbladder dysfunction.
Klieger PS. O'Mara RE.
Division of Nuclear Medicine, University of Rochester Medical Center, New York 14642, USA.
PURPOSE: Cholelithiasis is a common disorder occurring in over 20 million people in the United States and resulting in approximately 600,000 cholecystectomies annually. Although over 95% of biliary tract disease is caused by gallstones, the vast majority (>80%) of cholelithiasis cases are asymptomatic. The purpose of this study is to evaluate the utility of quantitative cholescintigraphy in detecting symptomatic biliary tract disease and predicting clinical relief after cholecystectomy. MATERIALS AND METHODS: Fifty-two patients with clinical symptoms of chronic cholecystitis were evaluated by cholescintigraphy with a gallbladder ejection fraction calculated after the intravenous administration of cholecystokinin. A gallbladder ejection fraction of > or =35% was considered a normal physiologic response. Forty-one of the patients subsequently underwent cholecystectomy, whereas the remaining 11 subjects were diagnosed and treated for non-biliary disorders that did not require cholecystectomies. After clinical follow-up including histopathological gallbladder findings, all subjects' final diagnoses were established and correlated with their quantitative cholescintigram study. RESULTS: Twenty-six of twenty-eight patients who had an abnormal quantitative cholescintigram demonstrated evidence of chronic cholecystitis by histopathologic criteria after cholecystectomy. Furthermore, 27 of these 28 patients (96%) experienced complete relief of their clinical symptoms after surgery. CONCLUSION: Functional cholescintigraphy is a safe, accurate, and useful test for detecting symptomatic gallbladder disease, and appears reliable in predicting symptomatic relief after cholecystectomy.
Usefulness of scintigraphy with Tc-99m phytate for the diagnosis of alcoholic foamy degeneration.
Shiomi S. Sasaki N. Yokogawa T. Kawada N. Sakaguchi H. Nakajima S. Kuroki T. Kawabe J. Ochi H.
Third Department of Internal Medicine, Osaka City University Medical School, Osaka, Japan.
PURPOSE: Alcoholic foamy degeneration (AFD) is a liver disease causing temporary hepatocyte dysfunction. The prognosis is usually good, but liver biopsy is needed for diagnosis. We report the usefulness of liver-spleen scintigraphy with the radiocolloid Tc-99m phytate for the diagnosis of AFD. PATIENTS AND METHODS: We used liver scintigraphy with Tc-99m phytate to study three patients with AFD diagnosed on the basis of findings from a liver biopsy. RESULTS: Liver-spleen scintigraphy showed hepatomegaly and splenomegaly, and bone marrow was visible, but radioisotope uptake by the liver was uniform. CONCLUSIONS: This pattern of scintigraphic findings is different from that reported for patients with alcoholic fatty livers or severe alcoholic hepatitis, and seems to be specific for AFD.
Radionuclide imaging in primary amyloidosis with liver involvement.
Chen SD. Kao CH. Poon SK.
Department of Nuclear Medicine, Taichung Veterans General Hospital, Taiwan, Republic of China.
A 74-year-old man with hepatomegaly, hyperglycemia, and proteinuria was diagnosed with primary amyloidosis with liver involvement, proven by biopsy. Abnormal distribution of tracer in the liver on Tc-99m phytate liver-spleen imaging and abnormal tracer uptake by the liver on Tc-99m pyrophosphate whole body imaging were observed. Scintigraphic imaging studies may be used noninvasively to evaluate the involvement of organs in patients with primary amyloidosis, reducing the risk of bleeding caused by biopsy.