CT of the liver in patients with metastatic breast carcinoma treated by chemotherapy: findings simulating cirrhosis.

OBJECTIVE: Although the hepatotoxic effects of systemic chemotherapy are well known, CT findings in the liver after systemic chemotherapy have received little attention in the literature. In some patients with breast carcinoma metastatic to the liver who have received chemotherapy, a morphologic pattern develops similar to that associated with cirrhosis. This pattern is characterized by a lobular hepatic contour, segmental volume loss, and enlargement of the caudate lobe. The purpose of this study was to describe the CT appearance of this pseudocirrhosis and to correlate it with pathologic findings. MATERIALS AND METHODS: We reviewed 65 CT examinations of 22 patients with stage IV breast carcinoma with hepatic metastases, who were receiving systemic chemotherapy and for whom abdominal CT scans showed pseudocirrhosis. Nineteen of 22 patients had follow-up CT scans at intervals ranging from 1 to 15 months. Criteria for the diagnosis of pseudocirrhosis included a lobular hepatic contour, segmental volume loss, and enlargement of the caudate lobe. CT findings were correlated with pathologic findings in seven patients. RESULTS: In all patients, CT scans showed retraction of the capsular surface of the liver (15 diffuse, seven focal) with a lobular margin, a finding also seen in advanced cirrhosis. The retraction occurred at the site of subjacent metastases. Findings evolved over 1-3 months. Six of seven patients had pathologic findings suggestive of nodular regenerative hyperplasia. No patients had pathologic evidence of cirrhosis. CONCLUSION: In patients undergoing systemic chemotherapy for breast cancer metastatic to the liver, a pattern may develop that mimics the CT appearance of hepatic cirrhosis. Pathologic findings suggest nodular regenerative hyperplasia as a possible cause.

Focal fatty infiltration: a cause of nontumorous defects in the left hepatic lobe during CT arterial portography.

OBJECTIVE: The purpose of this work was to determine the frequency and significance of characteristic nontumorous low attenuation defects found in the left hepatic lobe during CT arterial portography (CTAP). MATERIALS AND METHODS: Eighty CTAPs performed over a 17 month period were retrospectively reviewed to identify nonsegmental low attenuation defects adjacent to the falciform ligament, gallbladder, or porta hepatis. Twenty-four separate defects were present in 14 of 80 (18%) patients. Cases in which a defect was present were compared with MR, surgical findings, and pathology reports. RESULTS: The defects were oval or triangular in shape with a mean maximum diameter of 1.7 cm (range 1-5 cm). None of these defects were identified on MR in the 12 patients who underwent T1, T2, and STIR MR; however, 3 showed dropout of signal on chemical shift MR, suggesting fatty infiltration. In the 12 patients who underwent surgery, no lesion was shown to represent tumor. Two intraoperative biopsies of the area of the defects showed fatty infiltration. CONCLUSION: Nontumorous low attenuation defects adjacent to the gallbladder, falciform ligament, or porta hepatis are a pitfall of CTAP and can be associated with focal fatty infiltration, as well as decreased perfusion due to technical factors or a variation in hepatic vascular supply.

Stent placement for benign pancreatic diseases: correlation between ERCP findings and clinical response.

OBJECTIVE: We performed a study to determine if the appearance of the pancreatic duct on ERCP before and after placement of pancreatic duct stents correlates with the therapeutic response in patients treated for impaired pancreatic drainage. MATERIALS AND METHODS: Findings in 29 consecutive patients with a variety of benign pancreatic diseases in whom pancreatic stents were placed and subsequently removed within a 3-year period were reviewed retrospectively. Early (1-5 days) and late (1-3 months) clinical outcomes after stent placement were assessed. These findings were correlated with a blinded interpretation of ERCP findings (Cambridge criteria were used) before and after stent placement. RESULTS: ERCP findings before stent placement were normal in 10 patients. At the end of stent therapy, ERCP showed changes associated with chronic pancreatitis in all 10; five had focal narrowing at the tip of the stent. Subsequent ERCP studies in five of these 10 patients showed that ductal changes induced by stents diminished after stent removal. Of the 19 patients with abnormal findings on ERCP at the time of stent placement, ERCP at the end of stent therapy showed some improvement in seven patients, no change in eight, and deterioration in four. Changes seen on ERCP had no statistically significant correlation with clinical outcome (p = .36). CONCLUSION: Our findings show that pancreatic duct stents can induce abnormalities on ERCP indicative of chronic pancreatitis. However, diminution of these abnormalities after stent removal in some patients suggests that these changes may be due to edema rather than to fibrosis. Ductal changes seen on ERCP are not a useful guide for determining the degree of response to pancreatic stents.

Malignant biliary obstruction: efficacy of thin-section dynamic CT in determining resectability.

OBJECTIVE: Several authorities advocate the use of preoperative angiography to determine the resectability of pancreatic and periampullary tumors, claiming that CT alone is not sufficiently accurate for this purpose. Our objective was to assess the value of CT in predicting surgical resectability in patients with malignant biliary obstruction. MATERIALS AND METHODS: We performed a retrospective analysis of 380 consecutive cases of malignant biliary obstruction spanning a 4-year period. Most patients (230) were treated nonoperatively. Sixty-seven patients had surgery, pathologic confirmation of malignancy, and preoperative CT scans available for review. The CT scans were assessed for surgical resectability of tumor by an interpreter who did not know the patient's history. RESULTS: Forty-two patients had pancreatic adenocarcinoma, six had ampullary carcinoma, seven had cholangiocarcinoma, and 12 had other malignant neoplasms. Of 47 patients with tumors thought to be unresectable on the basis of CT findings, 42 had tumors that were found to be unresectable at surgery (positive predictive value, 89%). Of 20 patients with tumors thought to be resectable, 16 had tumors that were surgically resectable (positive predictive value, 80%). CT did not show metastases to duodenal lymph nodes (n = 2), portal vein infiltration (n = 1), and small hepatic metastases (n = 1). Visualization of most of these at angiography would not be expected. The CT finding of infiltration of the periarterial fat around the celiac or superior mesenteric arteries was reliable for predicting surgical unresectability. Lymphadenopathy and infiltration of nonperivascular fat planes were less reliable predictors of unresectability. CONCLUSION: Although some findings on CT that suggest unresectability are less reliable than others, the accuracy of CT compares favorably with reports on the accuracy of angiography for assessing tumor resectability in cases of malignant biliary obstruction. The addition of angiography to the examination of patients with potentially resectable lesions is not justified when high-quality, thin-section dynamic CT has been performed.

Bile duct diverticula and webs: nonspecific cholangiographic features of primary sclerosing cholangitis.

Biliary tree diverticula and webs are considered by several authors to be specific cholangiographic features of primary sclerosing cholangitis (PSC). Our experience suggested that these findings can be seen in patients without PSC. The purpose of this study was twofold: to establish whether diverticula and webs are indeed specific for PSC and to assess whether PSC can be accurately diagnosed without reference to diverticula or webs. We retrospectively reviewed 861 consecutive ERCP studies and found 32 cases of webs and/or diverticula. Using accepted cholangiographic, clinical, and histologic criteria, we diagnosed PSC in nine patients and excluded it in 21, with two instances of uncertain diagnoses. Webs and diverticula seen in PSC were cholangiographically indistinguishable from those in the group without PSC. All 21 patients without PSC had other biliary abnormalities, and were grouped by the predominant abnormality or finding believed to be associated with diverticulum or web formation: common duct stones or cholangitis (n = 11 patients), postoperative stricture (n = 4), bile duct stent and balloon dilatation (n = 3), malignant stricture (n = 2), and choledochoduodenostomy (n = 1). To assess cholangiographic diagnosis of PSC in these patients, a blinded reviewer studied the radiographs of the 30 patients with diverticula and/or webs who had confirmed diagnoses. By using established radiologic criteria alone (ignoring diverticula and webs), the correct diagnosis was made in 27, yielding a sensitivity of 89% and specificity of 91%. We conclude that the presence of diverticula and/or webs on a cholangiogram is a nonspecific finding and may be due to inflammation or trauma to the bile duct wall. Further, PSC can be distinguished from other abnormalities on the basis of findings other than diverticula and webs.

Anatomic variants and artifacts in ERCP interpretation.

ERCP is a complex diagnostic procedure requiring manual dexterity, careful attention to endoscopic and radiographic technique, and correct interpretation of the resulting images. Not surprisingly, the procedure is associated with many potential pitfalls. Many of these are related to normal anatomic pancreatic and biliary variants and to artifacts associated with the examination itself. Knowledge of these variants and artifacts is necessary to perform procedures and interpret the results effectively. Our discussion and illustrations are based on a retrospective review of approximately 1300 ERCP studies performed at a single center during a 2-year period.