Internal hernias after abdominal surgeries: MDCT features.

As less-invasive treatments for small bowel obstruction, such as laparoscopic surgery or small incision therapy, have become common, there is a growing demand for preoperative assessment of the cause and location of the small bowel obstruction. Thus, the role of computed tomography (CT) in the evaluation of small bowel obstruction is expanding. CT imaging of internal hernias (IHs) has been extensively described and is well established; however, CT imaging of IH after abdominal surgeries is not well recognized because of their anatomical complexity. The aims of this pictorial review are (1) to evaluate the causes of internal IHs in relation to previous abdominal surgery (e.g., IH associated with Roux-en-Y reconstruction, Billroth II reconstruction, peritoneal adhesive band, perineal hernia, and IH after gynecological procedures), (2) to demonstrate the spectrum of imaging findings on multidetector CT (MDCT), and (3) explain the key features for CT diagnosis of IHs related to previous surgical procedures, with emphasis on the multi-planar reformation (MPR) image. We also demonstrate the dynamic changes in the progression of mesenteric strangulation revealed by CT. Understanding the imaging appearance on MDCT can help radiologists guide therapy for patients with a small bowel obstruction after abdominal surgery.

Hepatocellular carcinoma: prediction of blood supply from right inferior phrenic artery by multiphasic CT.

OBJECTIVE: Recurrent hepatocellular carcinoma (HCC) often occurs with extrahepatic arterial supply (parasitic supply), essentially due to liver intraarterial chemoembolization, which could potentially hamper retreatment. The right inferior phrenic artery (RIPA) is the most frequent extrahepatic feeding artery. We investigated computed tomography (CT) findings of parasitic supply by the RIPA, and discuss the utility of multiphasic CT for prediction of parasitic supply from RIPA. METHOD: Medical records, CT scans, and angiograms in 20 patients with HCC fed by RIPA were reviewed. Forty-two patients with HCC but without parasitic supply were enrolled as the control group. After injection of contrast medium (300 mg I/mL) at a rate of 3 mL/s (total amount, 100 mL), CT images were obtained at 30 seconds, 60 seconds, and 150 seconds with scanning parameters of 7-mm collimation, 1:1 pitch, and 3.5-mm reconstruction. Two radiologists evaluated the previous treatment, patency of the hepatic arteries, location of tumors, and detectability and diameter of the RIPA. RESULTS: CT demonstrated at least one portion of RIPA in all patients in both groups. The distal portions of RIPA were detected on CT more frequently in the parasitic group (75%) than in the control group (7.1%). The mean diameter of the RIPA in the parasitic group was 2.3 mm (range; 1.6-3.8), and was larger than that of the control group (mean; 1.3 mm and range; 0-4.1mm) with statistical significance (P < 0.01). CONCLUSIONS: Multiphasic CT could demonstrate the presence of parasitic supply to HCCs from RIPA. Visualization of RIPA at the distal portion on CT would be a clue of parasitic supply from RIPA.

Mucin-producing carcinoma of the gallbladder: imaging demonstration in four cases.

We report four cases of mucin-producing carcinoma of the gallbladder (three papillary adenocarcinomas and one mucinous carcinoma), with an emphasis on imaging features. Our findings suggest that when a papillary protrusion or thickened wall, including cystic areas and/or calcifications, is seen radiologically in the enlarged gallbladder, mucin-producing carcinoma of the gallbladder should be included in the differential diagnosis.