Ryo Takaji

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. Index Terms: right inferior phrenic artery, hepatocellular carcinoma, parasitic supply, computed tomography

Balloon-Occluded Retrograde Transvenous Obliteration of Complex Gastric Varices Assisted by Temporary Balloon Occlusion of the Splenic Artery

Six cases of gastric varices with multiple afferent veins, in which balloon-occluded venography of the draining vein showed insufficient filling of gastric varices with contrast medium, were treated by balloon-occluded retrograde transvenous obliteration (BRTO) and temporary balloon occlusion of the splenic artery. The gastric varices were completely filled with sclerosant in all but one patient. No procedure-related complications were encountered. Computed tomography (CT) after the procedure showed complete thrombosis of the varices in five patients and partial thrombosis in one patient. Temporary balloon occlusion of the splenic artery is a useful additional technique for complete obliteration of gastric varices in selected cases.

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.

Partial Thrombosis of Gastric Varices After Balloon-Occluded Retrograde Transvenous Obliteration: CT Findings and Endoscopic Correlation

OBJECTIVE The purpose of our study was to investigate the frequency and outcomes of partial thrombosis of gastric varices after balloon-occluded retrograde transvenous obliteration (BRTO). MATERIALS AND METHODS We reviewed retrospectively 69 consecutive patients with gastric varices who were followed-up for > 6 months after treatment with BRTO. All patients underwent contrast-enhanced CT and gastroscopy before and after BRTO. Imaging findings of gastric varices with particular attention to afferent veins, degree of thrombosis, and variceal changes were investigated. RESULTS On the basis of pretherapeutic CT images, gastric varices were classified into two types: simple (< 3 afferent veins) and complex (≥ 3 afferent veins). Initial follow-up CT showed complete thrombosis in 58 patients (84%) and partial thrombosis in 11 (16%). Partial thrombosis was observed more frequently in complex-type varices (25% vs 9%). No regrowth or recurrent varices were observed in completely thrombosed varices. Follow-up endoscopy showed regrowth of gastric varices at 6-24 months after BRTO in five patients; all of these were complex-type and partially thrombosed varices. All five recurrent varices were treated successfully with repeated BRTO. CONCLUSION Partial thrombosis after BRTO can occur in complex-type gastric varices, which have a higher risk of regrowth. Additional techniques that achieve complete thrombosis are required for long-term efficacy for complex-type gastric varices.

Lymphatic pathway around the pancreatic head and extrahepatic bile duct: evaluation using MR imaging at 3.0-T

PurposeTo evaluate the utility of spectral presaturation with inversion recovery (SPIR) T2-weighted images with 3-dimensional (3D) volume isotropic turbo spin echo acquisition (VISTA) at 3.0-T for the detection of the normal lymphatic systems located around the pancreatic head and extrahepatic bile duct.Materials and methodsFifty-six patients with suspected hepatic or pancreaticobiliary diseases and diagnosed as normal or benign pathologies were evaluated as having normal lymphatic systems. The protocol consisted of SPIR T2-weighted sequences with 3D-VISTA. The lymphatic systems were defined as fluid signal intensity structures and divided into eight portions and interobserver agreement was evaluated using weighted kappa statistics. Three readers graded the visualization of each portion using a five-point scale. The detectability of each portion was calculated by defining grades 1–2 as detectable and grades 3–5 as undetectable.ResultsInterobserver agreement regarding the visualization grades was moderate to almost perfect. All readers rated the detectability of the lymphatic systems of the superior and posterior portions of the pancreatic head, pericholedochal, right abdominoaortic, and interaorticovenous portions as 100%, and that of the anterior portion of the pancreatic head as 98.2%. For the inferior portion of the pancreatic head, the detectability was 100% for reader 2 and 96.4% for readers 1 and 3.ConclusionThe lymphatic systems located around the pancreatic head and extrahepatic bile duct could be sufficiently visualized on SPIR T2-weighted images with 3D-VISTA at 3.0-T.

Extrahepatic Bile Duct Cancer: Invasion of the Posterior Hepatic Plexuses—Evaluation Using Multidetector CT

PURPOSE To assess the utility of axial and coronal reformatted multidetector computed tomographic (CT) images in the evaluation of the invasion of posterior hepatic plexuses by extrahepatic bile duct cancer. MATERIALS AND METHODS This retrospective study was approved by the institutional review board, and informed consent was waived. Forty-three patients (22 men, 21 women; age range, 40-80 years; mean age, 65 years) with surgically resected cancer involving the extrahepatic bile duct between December 2004 and September 2010 were included. Posterior hepatic plexus 1 runs from the superior and middle bile duct to the right celiac ganglion, and posterior hepatic plexus 2 runs between the lower bile duct and right celiac ganglion behind the portal vein. Invasion of the posterior hepatic plexuses was elucidated by using pathologic and postoperative multidetector CT findings. Three radiologists independently evaluated the preoperative axial and coronal reformatted images with a separate viewing session for the invasion of posterior hepatic plexuses that was detected on the basis of the presence of increased attenuation of fat tissue along the nerve routes. Receiver operating characteristic analysis was performed to compare the diagnostic performance of the two image interpretations. RESULTS Invasion of posterior hepatic plexus 1 and of posterior hepatic plexus 2 was recognized in 10 (23%) and nine (21%) of 43 patients, respectively. The diagnostic performance of coronal reformatted image interpretation was significantly greater than that for axial image interpretation (mean area under the curve, 0.99 vs 0.89, P = .04; mean accuracy, 95% vs 82%, P = .003). In all reviewers, one false-positive diagnosis of the invasion of posterior hepatic plexus occurred on axial and/or coronal image display types because of fibrosis and inflammatory cell infiltration along these plexus routes. CONCLUSION Coronal reformatted images can be useful for accurate diagnosis of the invasion of posterior hepatic plexuses and may facilitate surgical decision making in regard to the resection of celiac ganglion.

Perirenal lymphatic systems: Evaluation using spectral presaturation with inversion recovery T2 -weighted MR images with 3D volume isotropic turbo spin-echo acquisition at 3.0T.

To evaluate the normal anatomy of the perirenal lymphatics using spectral presaturation with inversion recovery (SPIR) T2‐weighted magnetic resonance imaging (MRI) with 3D volume isotropic turbo spin‐echo acquisition (VISTA) at 3.0T.

Fusion anomaly of the pancreatic tail and spleen: a case report

BackgroundSplenopancreatic fusion is a rare anomaly that is often associated with trisomy 13. Its diagnosis can be important in patients scheduled to undergo distal pancreatectomy or splenectomy, to avoid possible intraoperative or postoperative complications.Case presentationAn 82-year-old Japanese man was referred to our hospital for further evaluation and treatment for a solitary hepatocellular carcinoma based on liver cirrhosis. Triple-phase contrast-enhanced multidetector-row computed tomography and magnetic resonance imaging showed a splenopancreatic fusion as well as a solitary hepatocellular carcinoma in segment VIII of his liver.ConclusionsFusion of the pancreatic tail and spleen is a rare and asymptomatic anomaly. Its detection can be improved by the use of multidetector computed tomography or magnetic resonance imaging.

Asymptomatic Bartholin Cyst: Evaluation With Multidetector Row Computed Tomography

Objective The aim of this study was to determine the frequency, morphology, and attenuation characteristics of Bartholin cysts on multidetector computed tomography (MDCT) in asymptomatic women. Methods A total of 3280 consecutive MDCT examinations were assessed for Bartholin cysts. The diagnosis was based on shape, contrast enhancement, and anatomical location. Age, laterality, size, and attenuation patterns were recorded. Scans from patients with paravaginal-related symptoms were excluded, and any available follow-up MDCT scans or magnetic resonance images were evaluated. Results Asymptomatic Bartholin cysts were seen in 17 patients (0.52%) (mean age, 56 years). The mean maximum cyst diameter was 21.8 mm. High-attenuation cysts comprised 47% of cases, all in older (≥50 years) patients. Follow-up MDCT scans showed minimal changes over time. Conclusions High-attenuation Bartholin cysts are more common than previously thought and are usually seen in older women. The size and attenuation of Bartholin cysts show only minimal changes over time.

Beak-Like Extension of the Pancreatic Uncinate Process on MDCT: Is It Hyperplasia or Movement?

Objective We aimed to evaluate the pancreatic uncinate process with a beak-like extension (BLE) beyond the left border of the superior mesenteric artery, to define the cause of BLE, and to differentiate BLE from hyperplasia. Methods We retrospectively reviewed 1042 triple-phase contrast-enhanced multidetector-row computed tomography (3P-CE-MDCT) examinations of 500 patients. Finally, 38 patients (28 men, 10 women; mean age, 66 years) with 140 3P-CE-MDCT images showing BLE were studied regarding BLE size, contour, and cause. The superior mesenteric artery position was also evaluated. Results Beak-like extensions were found in 7.6% of patients. Most were caused by movement of the small bowel mesentery (n = 21, 55%), with deviation of mesenteric vessels or mass effect from expanded adjacent organs (n = 3, 8%). Seven patients (18.5%) had true hyperplasia. Conclusions Beak-like extension is caused by movement of the small bowel mesentery with deviation of mesenteric vessels or by adjacent organ expansion. Beak-like extension closely mimics other pathology on nonenhanced MDCT.