Renal manifestations of AIDS

The kidneys in patients with acquired immunodeficiency syndrome (AIDS) are subject to a variety of insults. Renal manifestations can be seen with imaging studies of AIDS patients. Computed tomographic (CT) and ultrasound (US) scans of 64 patients with AIDS and renal dysfunction were retrospectively reviewed and compared with clinical, laboratory, and, when available, biopsy results. Imaging abnormalities included increased cortical echogenicity, nephromegaly, pyelonephritis, lobar nephronia, focal masses caused by abscess and lymphoma, parenchymal calcification, hydronephrosis, and infarct. Generally, patients with AIDS as a result of intravenous drug abuse and those with multiple risk factors were more likely to have abnormalities demonstrated at imaging as well as poorer prognosis than were patients in the homosexual transmission group in this series. Although US should be the screening study used in patients with AIDS and suspected renal dysfunction, CT and magnetic resonance imaging may be necessary to identify focal infectious, ischemic, and neoplastic processes.

Appendices epiploicae of the colon: radiologic and pathologic features

Appendices epiploicae are adipose structures protruding from the serosal surface of the colon. They can be seen with abdominal radiography and cross-sectional imaging if the colonic wall is surrounded by intraperitoneal contrast material, ascites, or blood. Normal appendices epiploicae appear as lobulated masses of pericolic fat, usually 2-5 cm long and 1-2 cm thick. Their enlargement, deformity, or altered radiopacity may result from various pathologic processes that can originate locally or extend from adjacent viscera. In a series of 22 cases, appendices epiploicae were affected by spontaneous torsion and hemorrhagic infarct, calcification due to aseptic fat necrosis, primary or secondary inflammation, enlargement by lipomas or metastases, and incarceration in hernias. Disorders of appendices epiploicae are often manifested by nonspecific clinical signs and symptoms (eg, torsion is often mistaken for appendicitis or diverticulitis). These entities should be included in the differential diagnosis of any unexplained abdominal pain or pericolic lesions in adults.

MRI of hepatic iron deposition in patients with renal transplant

Excess hepatic iron deposition was found in five of 15 (33%) renal transplant patients undergoing magnetic resonance (MR) screening for avascular necrosis of the femoral heads. Only one of these patients had overt liver disease. The number of prior blood transfusions was a significant factor for this deposition, whereas the age and sex of the patients, number and type of transplants, histocompatibility alleles (HLA), and years of hemodialysis and of chronic renal failure were not significant etiological factors. Liver/fat intensity ratios of less than 0.29 on T1-weighted images and ratios of less than 0.21 on T2-weighted images and a calculated T2 value of less than 35 ms were the best indicators of iron overload. Renal transplant patients are at great risk for excess hepatic iron deposition and MR imaging is a promising tool for the diagnosis of iron overload in this patient population.

Diverticulitis of the duodenum: clinical and radiological manifestations of seven cases

Seven patients with duodenal diverticulitis were evaluated by computed tomography (CT) and various other abdominal imaging techniques. The series included four men and three women who ranged in age from 47 to 84 yr (mean: 65 yr). They had presented with epigastric or periumbilical pain, low-grade fever, leukocytosis, and loss of appetite and weight due to postprandial cramps or vomiting. In each instance, the abdominal CT examination proved crucial in the diagnosis of duodenal diverticulitis, with contained perforation or inflammatory changes involving the adjacent structures. Five patients underwent laparotomy while two others were treated conservatively with antibiotics and/or percutaneous drainage of peridiverticular abscess. The clinical and radiological features of this uncommon entity are herein described, along with a brief review of the medical literature regarding the current approach to its diagnosis and management.

CT of inflammatory bowel disease

Computed tomography (CT) provides an important perspective in patients with inflammatory bowel disease that often has a profound influence on the therapeutic decision-making process. By virtue of its ability to image the bowel wall, serosa, and mesentery directly and noninvasively, CT can diagnose infectious and inflammatory complications that often can only be inferred indirectly by barium studies and endoscopy.

CT diagnosis of postoperative abdominal complications

Over 3 million abdominal operations are performed in the United States each year, and a significant number of these patients subsequently undergo computed tomography (CT) either for follow-up of resected lesions or evaluation of possible postoperative complications. This article describes the clinical presentations and CT features of commonly encountered postsurgical complications. A wide spectrum of lesions involving the abdominal wall as well as intraperitoneal structures is herein illustrated to emphasize the role of CT in their diagnosis and management.

Acquired malposition of the colon and gallbladder in patients with cirrhosis: CT findings and clinical implications

Topographic relationships among the gallbladder, liver, hepatic flexure of the colon, right hemidiaphragm, and anterolateral peritoneal reflection were evaluated with computed tomography in 75 patients with biopsy-proved cirrhosis and in 200 control subjects to determine the effect of cirrhotic liver morphology on the anatomy of the right upper quadrant of the abdomen. Interposition of the colon between the liver and anterolateral abdominal wall and/or diaphragm was seen in 18 of the 75 (24%) cirrhotic patients and in six of the 200 (3%) control subjects. There was a strong correlation among gallbladder malposition, colonic interposition, and a ratio of transverse caudate lobe width to right lobe width (C/RL) exceeding 0.60. Patients with cirrhosis, colonic interposition, and gallbladder malposition had a mean C/RL of 0.62, compared with a mean of 0.50 for cirrhotic patients without interposition (P less than .0001). The mean C/RL for control subjects without interposition was 0.43, as compared with 0.69 for control subjects with interposition (P less than .01). These acquired malpositions of the colon and gallbladder may pose a diagnostic dilemma and increase the risk of inadvertent injury during percutaneous liver biopsy, interventional biliary tract procedures, and laparotomy.

Lymphadenopathy in chronic active hepatitis: CT observations

CT scans were obtained in 17 patients who had biopsy-proved chronic active hepatitis in order to evaluate deteriorating liver function and clinical status. Lymphadenopathy in the porta hepatis and/or retroperitoneum was found in 11 patients (65%), and this was the only CT indication of significant hepatic disease in six patients (35%). In three of five patients who subsequently underwent immunosuppressive therapy, serial biopsy, and CT scanning, clinical and histologic improvement in the condition of the liver were accompanied by a reduction in lymph-node size on CT. These findings suggest that abdominal adenopathy is a frequent CT finding in patients who have chronic active hepatitis and might be a useful marker in monitoring immunotherapy.

Thrombosis of the splanchnic veins: CT diagnosis

Fourteen patients had mesenteric, portal, or splenic venous thrombosis that was diagnosed primarily by contrast-enhanced CT. The group included five patients with coagulopathy, three with pancreatic carcinoma, two with cirrhosis and portal hypertension, one with pancreatitis, and one with hepatocellular carcinoma. In two patients, no etiology was determined. In all cases, CT easily identified low-density venous thrombosis, which frequently involved more than one vein. In four patients, all three splanchnic veins were involved; five patients had occlusion of two veins. In five patients, only one vein was involved. Additional CT findings included ascites, collateral veins, hepatomegaly, and splenomegaly. No venous wall enhancement was found. CT also was helpful in defining the cause of thrombosis in six of 14 patients. Mesenteric edema and/or bowel wall thickening was not identified. None of the patients had classic clinical evidence of splanchnic venous occlusion, and none died primarily of that disease. The major morbidity suffered by these patients stemmed from complications of splanchnic venous occlusion, and nine patients ultimately required sclerotherapy, splenectomy, and portal decompression. We conclude that CT is useful in the diagnosis of splanchnic venous thrombosis. Our experience suggests that mesenteric, splenic, and/or portal venous thrombosis may occur more commonly than has been previously thought and that the disease in many cases is not life threatening.

A comparative study of computed tomography and ERCP in pancreaticobiliary disease

Fifty-seven patients with suspected pancreaticobiliary pathology constituting a clinical subset in whom the diagnosis was problematic or nonspecific were evaluated with computed tomography and ERCP. The relative sensitivities, specificities, and accuracies of the two tests were compared. Computed tomography was successful in obtaining a diagnostic examination in 100% and ERCP was technically successful in 75%. Both tests were equally accurate in detecting an abnormality (computed tomography 95.7%; ERCP 95.3%) and offering a correct diagnosis (computed tomography 72%; ERCP 70%). Sensitivity and specificity of the two tests for detection of an abnormality was computed tomography 100% and 91.3%; ERCP 91.7% and 100%. Sensitivity and specificity for the correct diagnosis was computed tomography 59% and 91.3%; ERCP 46% and 100%. Computed tomography was also superior to ERCP in making a correct diagnosis in pancreatic carcinoma (80% versus 63%) and pancreatitis (75% versus 50%). Based on these results we conclude that computed tomography utilizing high doses of intravenous contrast material and thin collimation is the preferred screening examination for pancreaticobiliary disease. ERCP should be reserved for those cases where the pancreaticobiliary disease. ERCP should be reserved for those cases where the diagnosis on computed tomography is obscure or uncertain and/or the pancreatic or biliary ductal anatomy requires direct contrast imaging.

Budd-Chiari syndrome: CT observations

The authors describe four patients with Budd-Chiari syndrome in whom contrast material-enhanced computed tomographic (CT) scans demonstrated low-density venous thrombosis in three sites not, to our knowledge, previously described with this modality. Thrombosis was seen in the portal circulation, the hepatic veins, and the intrahepatic inferior vena cava. It is known that concomitant portal vein thrombosis may be seen in 20% of patients with Budd-Chiari syndrome. Three of the four patients in the current study had this finding, one with extensive thrombosis of portal, mesenteric, and splenic veins and the other two with portal vein branch involvement. In one patient hepatic vein thrombosis was demonstrated with CT, and in three inferior vena cava clot was demonstrated. All four patients had the distinctive hepatic parenchymal contrast enhancement pattern seen in this condition, which the authors think may be at least partially caused by associated portal thrombosis. The presence of portal venous thrombosis should prompt the observer to consider the diagnosis of Budd-Chiari syndrome. Detection of hepatic vein clot confirms the diagnosis and may be seen in this condition in association with inferior vena cava thrombus.

Evaluation of ectopic bone by CT

The CT appearance of ectopic bone and its maturation in 25 patients were correlated with the findings on radiographs and bone scans. Ossification progressed from an early appearance of soft-tissue density of lower attenuation than muscle to a calcific density paralleling radiographic and scintigraphic evidence of bone formation. Persistent unossified, low-density soft tissue was detected adjacent to mineralized areas of ectopic bone in 14 patients up to 16 years after neurologic injury, often with bone-scan evidence of maturity of the ectopic bone. This soft tissue most likely corresponds to immature, unossified connective tissue, which may have a potential for ossification. Detection of areas of soft-tissue density by CT and their avoidance during surgical resection of an ankylosing mass of ectopic bone may reduce intraoperative hemorrhage and postoperative ectopic bone recurrence.

Bolus-rapid infusion of contrast medium: simplified technique for optimal computed tomography pancreatography without use of dynamic scanning

Optimal pancreatic computed tomography demands the use of both narrow beam collimation and high levels of intravascular contrast medium. Dynamic scanning with or without table incrementation has been advocated, but not all patients are amenable to prolonged breath holding, and tube cooling requirements may limit the study. In addition, repeat boluses usually must be administered to adequately image the entire pancreas. Enhancement may also be less than uniform. We describe a simple method of pancreatic scanning using bolus injection and pressurized rapid infusion of contrast medium that yields consistently high-quality scans demonstrating both pancreatic parenchymal and peripancreatic vascular enhancement in most patients. The method eliminates the need for dynamic scans in most cases and improves the speed of examination and quality of patient care in a busy computed tomography department.

Cross-sectional imaging of inflammatory bowel disease

The cross-sectional imaging modalities provide an important diagnostic perspective in patients with inflammatory bowel disease that often has a profound influence on the therapeutic decision-making process. They can directly and noninvasively image infectious and inflammatory complications involving the bowel wall, serosa, and mesentery that can only be assessed indirectly by colonoscopy and barium studies. At the present time, CT is superior to ultrasound and MR in diagnosing these extramucosal complications.

Duodenal manifestations of nontropical sprue

Barium studies of the upper gastrointestinal tract and small bowel were performed in 16 adult patients with biopsy-proven nontropical sprue. Commercially available contrast media containing micropulverized barium sulfate, suspending agents, and various other additives were used. Radiographs were analyzed for the incidence and pattern of duodenal vs. small-bowel changes associated with celiac disease. Thirteen of 16 patients (81%) demonstrated abnormalities of the duodenum which ranged from focal erosions to diffusely thickened and nodular folds. A nonspecific, mild dilatation pattern was present on the small-bowel series of 11 patients (69%). The classic radiographic signs of malabsorption, such as flocculation and segmentation, however, occurred in less than 20% of cases, apparently because of the stability of new barium suspensions. The pathogenesis of duodenal changes in sprue and its diagnostic implications are emphasized.

Value of computed tomography in the detection of complications of Crohn's disease

Abdominal and pelvic computed tomography (CT) scans were performed on 17 patients with suspected complications of Crohn's disease. CT was superior to conventional barium studies and colonoscopy in demonstrating mural, serosal, and mesenteric pathology such as bowel wall thickening (100%), abscess (59%) and phlegmon (6%) formation, and fibro-fatty proliferation of the mesentery (41%). While not advocated as the primary means of evaluating Crohn's disease, CT can provide information vital to the management of complications of this disease.

Brain edema: ultrasound examination

Sonographic examination of the brain in 10 patients who had cortical mass lesions was performed. Results were compared with findings of CT. In each case, brain edema surrounded the lesion, and the adjacent white matter had a diffusely echo-genic appearance that corresponded to the area of brain edema seen on CT.

Inferior vena cava CT pseudothrombus produced by rapid arm-vein contrast infusion

Laminar flow within the inferior vena cava can cause artifacts that may simulate thrombus if a foot-vein infusion is used. A "pseudothrombus" artifact within the suprarenal inferior vena cava produced by rapid infusion of contrast material through an arm vein is reported. This artifact was noted in 25 patients in a 6 month period and was believed to be from laminar flow of renal venous effluent of increased opacity around less opacified infrarenal caval contents. Differentiation from true thrombus can be made by the use of delayed scans as well as the increased density and relatively poor margination of the artifact.