Ten-year follow-up of cavoportal hemitransposition in pediatric liver transplantation for complete portomesenteric venous thrombosis: A case report and literature review.

BACKGROUND: Portal vein thrombosis is a potentially devastating complication following pediatric liver transplantation. In rare instances of complete portomesenteric thrombosis, cavoportal hemitransposition may provide graft inflow. Here we describe long-term results following a case of pediatric cavoportal hemitransposition during liver transplantation and review the current pediatric literature. METHODS: A 9-month-old female with a history of biliary atresia and failed Kasai portoenterostomy underwent living donor liver transplantation, which was complicated by portomesenteric venous thrombosis. The patient underwent retransplantation with cavoportal hemitransposition on postoperative day 12. OUTCOME: The patient recovered without further complication, and 10 years later, she continues to do well, with normal graft function and no clinical sequelae of portal hypertension. CT scan with 3-D vascular reconstruction demonstrated recanalization of the splanchnic system, with systemic drainage to the inferior vena cava via an inferior mesenteric vein shunt. The cavoportal anastomosis remains patent with hepatopetal flow. Of the 12 previously reported cases of pediatric cavoportal hemitransposition as portal inflow in liver transplantation, this is the longest-known follow-up with a viable allograft. Notably, sequelae of portal hypertension were also rare in the 12 previously reported cases, with no cases of long-term renal dysfunction, lower extremity edema, or ascites. CONCLUSIONS: Long-term survival beyond 10 years with normal graft function is feasible following pediatric cavoportal hemitransposition. Complications related to portal hypertension were generally short-lived, likely due to the development of robust collateral circulation. Additional reports of long-term outcomes are necessary to facilitate informed decision making when considering pediatric cavoportal hemitransposition for liver graft inflow.

Prospective comparison of positron emission tomography (PET)/magnetic resonance and PET/computed tomography dosimetry in hepatic malignant neoplastic disease after 90Y radioembolization treatment.

Background: 90Y radioembolization is an established treatment modality for hepatic malignancies. Successful radioembolization requires optimal dose delivery to tumors while minimizing dosages to parenchyma. Post-treatment positron emission tomography (PET)/computed tomography (CT) dosimetry is the established benchmark, whereas PET/magnetic resonance (MR) is an emerging modality. The goal of this study was to assess the intermodality agreement between PET/MR and PET/CT 90Y dosimetry. Methods: In this single-institution study, 18 patients (20 treatment sessions) with a primary or metastatic hepatic malignancy underwent both PET/MR and PET/CT after 90Y radioembolization. Patients were randomized to undergo one modality first, followed by the other. The region of interest was delineated using MR images and tumor and liver dosimetry was calculated. Intermodality agreement was assessed using the Bland-Altman method. A generalized linear model was used to assess the effect of baseline variables on intermodality dose differences. Results: PET/MR underestimated tumor and liver absorbed doses when compared to PET/CT by -3.7% (P=0.042) and -5.8% (P=0.029), respectively. A coverage probability plot demonstrated that 80% and 90% of tumor dose measurements fell within intermodality differences of 11% and 18%, respectively. PET/MR underestimated tumor dose at both low (<1 GBq) and high (>3 GBq) injected activity levels (P<0.001) by -22.3 [standard deviation (SD) =13.5] and -24.3 (SD =18.7), respectively. Conclusions: Although PET/MR significantly underestimated the absorbed dose when compared to PET/CT, the intermodality agreement was high and the degree of underestimation was better than previously reported. Intermodality differences were more pronounced at low and high injected doses. Additional studies are required to assess the clinical implications of these findings.

Surgical infective endocarditis and concurrent splenic abscess requiring splenectomy: a case series and review of the literature.

Splenic abscess is an uncommon but serious complication of infective endocarditis (IE). The timing of surgical management of splenic abscess can be challenging when valve surgery is required. The American Heart Association (AHA) and the European Society of Cardiology (ESC) currently recommends splenectomy before valve replacement due to fear of reinfection of the heart valve; however, published data to support this recommendation are limited. In this series, we report outcomes for 5 patients with IE and splenic abscess who underwent valve replacement first, followed by splenectomy at a median of 19 days (range: 10-77 days) after valve surgery, with no recurrent infection of the new valve. Our experience and review of the available literature provide reassurance for splenectomy after valve surgery for IE.

Hepatic capsular retraction: An updated MR imaging review.

Hepatic capsular retraction is a morphologic descriptor that refers to invagination or focal flattening of the typical smooth contour of the liver capsule. It is an uncommon finding that, when combined with other imaging features and clinical context, can help to refine the differential diagnosis in patients with liver lesions. Although this descriptor has historically been used in reference to a small subset of benign and malignant lesions, the differential has since been expanded with the discovery of new entities causing capsular retraction as well as with novel and increased use of liver-directed treatment techniques. Additionally, modern imaging techniques now allow for improved detection and characterization of capsular retraction. In this review, we discuss these common and uncommon causes of capsular retraction, with an emphasis on findings from body MRI.

How We Do It: Creating Consistent Structure and Content in Abdominal Radiology Report Templates.

OBJECTIVE: The purposes of this article are to describe the creation of template report formats and content for a variety of abdominal and pelvic CT and MRI examinations and discuss a review-of-systems approach to text and avoidance of pitfalls of report templates. CONCLUSION: Organ system-specific report templates for CT and MRI incorporate radiologist preferences. Disease-specific report templates are created from these reports to provide a consistent radiologist and referring physician experience across the report templates.

Splenosis: a great mimicker of neoplastic disease.

Splenosis is a benign condition that can occur after splenic trauma or after surgery involving the spleen. These splenic implants are most often seen within the abdominal and pelvic cavities. On imaging, splenosis can be confused with multiple additional entities including metastatic disease, peritoneal carcinomatosis, peritoneal mesothelioma, abdominal lymphoma, renal cancer, hepatic adenomas, or endometriosis depending on its distribution. In all patients with history of splenic surgery or trauma, splenosis should be on the differential diagnosis of soft tissue nodules in the abdomen and pelvis, especially in the absence of systemic symptoms, to avoid unnecessary biopsy, chemotherapy, or surgery.

Liver transplantation in patients with incidental hepatocellular carcinoma/cholangiocarcinoma and intrahepatic cholangiocarcinoma: a single-center experience.

BACKGROUND: Reports of liver transplantation (LT) in patients with mixed hepatocellular carcinoma/cholangiocarcinoma (HCC/CC) and intrahepatic cholangiocarcinoma (ICC) are modest and have been mostly retrospective after pathological categorization in the setting of presumed HCC. Some studies suggest that patients undergoing LT with small and unifocal ICC or mixed HCC/CC can achieve about 40%-60% 5-year post-transplant survival. The study aimed to report our experience in patients undergoing LT with explant pathology revealing HCC/CC and ICC. METHODS: From a prospectively maintained database, we performed cohort analysis. We identified 13 patients who underwent LT with explant pathology revealing HCC/CC or ICC. RESULTS: The observed recurrence rate post-LT was 31% (4/13) and overall survival was 85%, 51%, and 51% at 1, 3 and 5 years, respectively. Disease-free survival was 68%, 51%, and 41% at 1, 3 and 5 years, respectively. In our cohort, four patients would have qualified for exception points based on updated HCC Organ Procurement and Transplantation Network imaging guidelines. CONCLUSIONS: Lesions which lack complete imaging characteristics of HCC may warrant pre-LT biopsy to fully elucidate their pathology. Identified patients with early HCC/CC or ICC may benefit from LT if unresectable. Additionally, incorporating adjunctive perioperative therapies such as in the case of patients undergoing LT with hilar cholangiocarcinoma may improve outcomes but this warrants further investigation.

Imaging Manifestations of Hematologic Diseases with Renal and Perinephric Involvement.

The kidneys and perinephric tissues can be affected by a variety of hematologic disorders, which usually occur in the setting of multisystem involvement. In many of these disorders, imaging is used to evaluate the extent of disease, guide biopsy, and/or monitor disease activity and patient response to therapy. Lymphoma, leukemia, and multiple myeloma commonly manifest as multiple parenchymal or perinephric lesions. Erdheim-Chester disease and Rosai-Dorfman disease, rare forms of multisystemic histiocytosis, are often identified as perinephric and periureteral masses. Renal abnormalities depicted at imaging in patients with sickle cell disease include renal enlargement, papillary necrosis, and renal medullary carcinoma. Sickle cell disease, along with other causes of intravascular hemolysis, can also lead to hemosiderosis of the renal cortex. Thrombosis of renal veins is sometimes seen in patients with coagulation disorders but more often occurs in association with certain malignancies and nephrotic syndrome. Immunoglobulin G4-related sclerosing disease is another multisystem process that often produces focal renal lesions, seen along with involvement of more characteristic organs such as the pancreas. Perinephric lesions with calcifications should raise the possibility of secondary amyloidosis, especially in patients with a history of lymphoma and multiple myeloma. Although the imaging patterns of renal and perinephric involvement are usually not specific for a single entity, and the same entity can manifest with different or overlapping patterns, familiarity with these patterns and key clinical and histopathologic features may help to narrow the differential diagnosis and determine the next step of care. (©)RSNA, 2016.

Diagnostic Accuracy of CT Enterography for Active Inflammatory Terminal Ileal Crohn Disease: Comparison of Full-Dose and Half-Dose Images Reconstructed with FBP and Half-Dose Images with SAFIRE.

Purpose To compare the diagnostic accuracy and image quality of computed tomographic (CT) enterographic images obtained at half dose and reconstructed with filtered back projection (FBP) and sinogram-affirmed iterative reconstruction (SAFIRE) with those of full-dose CT enterographic images reconstructed with FBP for active inflammatory terminal or neoterminal ileal Crohn disease. Materials and Methods This retrospective study was compliant with HIPAA and approved by the institutional review board. The requirement to obtain informed consent was waived. Ninety subjects (45 with active terminal ileal Crohn disease and 45 without Crohn disease) underwent CT enterography with a dual-source CT unit. The reference standard for confirmation of active Crohn disease was active terminal ileal Crohn disease based on ileocolonoscopy or established Crohn disease and imaging features of active terminal ileal Crohn disease. Data from both tubes were reconstructed with FBP (100% exposure); data from the primary tube (50% exposure) were reconstructed with FBP and SAFIRE strengths 3 and 4, yielding four datasets per CT enterographic examination. The mean volume CT dose index (CTDIvol) and size-specific dose estimate (SSDE) at full dose were 13.1 mGy (median, 7.36 mGy) and 15.9 mGy (median, 13.06 mGy), respectively, and those at half dose were 6.55 mGy (median, 3.68 mGy) and 7.95 mGy (median, 6.5 mGy). Images were subjectively evaluated by eight radiologists for quality and diagnostic confidence for Crohn disease. Areas under the receiver operating characteristic curves (AUCs) were estimated, and the multireader, multicase analysis of variance method was used to compare reconstruction methods on the basis of a noninferiority margin of 0.05. Results The mean AUCs with half-dose scans (FBP, 0.908; SAFIRE 3, 0.935; SAFIRE 4, 0.924) were noninferior to the mean AUC with full-dose FBP scans (0.908; P < .003). The proportion of images with inferior quality was significantly higher with all half-dose reconstructions than with full-dose FBP (mean proportion: 0.117 for half-dose FBP, 0.054 for half-dose SAFIRE 3, 0.054 for half-dose SAFIRE 4, and 0.017 for full-dose FBP; P < .001). Conclusion The diagnostic accuracy of half-dose CT enterography with FBP and SAFIRE is statistically noninferior to that of full-dose CT enterography for active inflammatory terminal ileal Crohn disease, despite an inferior subjective image quality. (©) RSNA, 2016 Online supplemental material is available for this article.

Noninvasive Imaging of the Biliary Tree for the Interventional Radiologist.

Patients with suspected biliary tract disease often pose a diagnostic challenge to the clinician and radiologist. Although advances across all imaging modalities, including ultrasound, computed tomography, and magnetic resonance, have improved our diagnostic accuracy for biliary disease, many of the imaging findings remain nonspecific. Recognition of key imaging findings combined with knowledge and understanding of the clinical context is essential to piecing together a diagnosis and guiding management for patients with biliary disease. Although there is a wide range of biliary pathology, interventional radiologists most commonly play a role in the management of biliary obstruction and leak.

Patterns of cancer recurrence in localized resected hepatocellular carcinoma.

BACKGROUND: Tumor resection in non-metastatic hepatocellular carcinoma (HCC) patients with adequate liver reserve offers a potential cure, but has a high 5-year recurrence rate. We analyzed the patterns of cancer relapse after partial hepatectomy to guide post-operative management. METHODS: A total of 144 HCC patients (1996-2011) after partial hepatectomy were reviewed. Statistical correlations were determined using univariate and partition analyses. RESULTS: A median follow-up of 20 months showed recurrence in 71 (49%) patients, and the median time to recurrence was 11.9 months. Vascular invasion (P<0.01) and number of lesions (P<0.01) predicted for recurrence. Histologic grade was not correlated with recurrence. Twenty-two (31%) patients developed both surgical margin (SM) and concurrent intrahepatic recurrences, and 28 (40%) had non-SM intrahepatic recurrences with no other signs of recurrence. On partition analysis, the risk of marginal recurrence in patients with SM <1 mm and SM ≥1 mm was 35% and 13.5% respectively. Approximately 57% of patients with intrahepatic recurrence had recurrence ≤2.5 cm from SM. CONCLUSIONS: Intrahepatic recurrence after partial hepatectomy is common and is significantly associated with vascular invasion and tumor stage. About 57% of patients with intrahepatic relapse had a recurrence close (≤2.5 cm) to the SM. Additionally, patients with SM <1 mm have a higher recurrence rate and may benefit from adjuvant local therapy.

Benign and malignant tumors of the rectum and perirectal region.

Although most rectal masses are histologically characterized as adenocarcinomas, the rectum and perirectal region can be affected by a wide variety of tumors and tumor-like conditions that can mimic the symptoms caused by rectal adenocarcinoma, including mucosal or submucosal rectal tumors such as lymphoma, gastrointestinal stromal tumor, leiomyosarcoma, neuroendocrine tumor, hemangioma, and melanoma, as well as tumors of the perirectal region such as developmental cyst, neurogenic tumor, osseous tumor, and other miscellaneous conditions. As a group, tumors of the rectum are considerably different from the group of tumors that arise in the perirectal region: they are most often neoplastic, symptomatic, and malignant, whereas tumors arising in the perirectal region are most commonly congenital, asymptomatic, and benign. Proctoscopy with biopsy is the most important method for the diagnosis of rectal tumors, but this procedure cannot determine the precise intramural extension of a rectal tumor and cannot accurately distinguish submucosal and intramural tumors from extramural tumors. Cross-sectional imaging, especially transrectal ultrasound and magnetic resonance imaging, allows evaluation of the entire bowel wall thickness and the perirectal tissues, helping further characterize these tumors. Recognition of the existence of these masses and their key clinical and imaging features is crucial for clinicians to accurately diagnose and appropriately manage these conditions.

Role of tissue expanders in patients with loss of abdominal domain awaiting intestinal transplantation.

Abdominal closure is a complex surgical problem in intestinal transplant recipients with loss of abdominal domain, as graft exposure results in profound morbidity. Although intraoperative coverage techniques have been described, this is the first report of preoperative abdominal wall augmentation using tissue expanders in patients awaiting intestinal transplantation. We report on five patients who received a total of twelve tissue expanders as a means to increase abdominal surface area. Each patient had a compromised abdominal wall (multiple prior operations, enterocutaneous fistulae, subcutaneous abscesses, stomas) with loss of domain and was identified as high risk for an open abdomen post-transplant. Cross-sectional imaging and dimensional analysis were performed to quantify the effect of the expanders on total abdominal and intraperitoneal cavity volumes. The overall mean increase in total abdominal volume was 958 cm(3) with a mean expander volume of 896.5 cc. Two expanders were removed in the first patient due to infection, but after protocol modification, there were no further infections. Three patients eventually underwent small bowel transplantation with complete graft coverage. In our preliminary experience, abdominal tissue expander placement is a safe, feasible, and well-tolerated method to increase subcutaneous domain and facilitate graft coverage in patients undergoing intestinal transplantation.

LI-RADS: a case-based review of the new categorization of liver findings in patients with end-stage liver disease.

Hepatocellular carcinoma (HCC) is a global health problem, with the burden of disease expected to increase in the coming years. Patients who are at increased risk for developing HCC undergo routine imaging surveillance, and once a focal abnormality is detected, evaluation with multiphasic contrast material-enhanced computed tomography or magnetic resonance imaging is necessary for diagnosis and staging. Currently, findings at liver imaging are inconsistently interpreted and reported by most radiologists. The Liver Imaging-Reporting and Data System (LI-RADS) is an initiative supported by the American College of Radiology that aims to reduce variability in lesion interpretation by standardizing report content and structure; improving communication with clinicians; and facilitating decision making (eg, for transplantation, ablative therapy, or chemotherapy), outcome monitoring, performance auditing, quality assurance, and research. Five categories that follow the diagnostic thought process are used to stratify individual observations according to the level of concern for HCC, with the most worrisome imaging features including a masslike configuration, arterial phase hyperenhancement, portal venous phase or later phase hypoenhancement, an increase of 10 mm or more in diameter within 1 year, and tumor within the lumen of a vein. LI-RADS continues to evolve and is expected to integrate a series of improvements in future versions that will positively affect the care of at-risk patients.

Characteristics and distinguishing features of hepatocellular adenoma and focal nodular hyperplasia on gadoxetate disodium-enhanced MRI.

OBJECTIVE: The purpose of this study is to evaluate the performance of gadoxetate disodium-enhanced MRI in the characterization of focal nodular hyperplasia (FNH) and hepatocellular adenoma and to assess potential advantages of hepatocyte phase imaging in identifying features that distinguish FNH from hepatocellular adenoma. MATERIALS AND METHODS: Gadoxetate disodium-enhanced MRI examinations of 12 patients with hepatocellular adenoma and 35 patients with FNH were retrospectively evaluated by three blinded readers. Diagnoses and confidence scores were recorded before and after disclosure of hepatocyte phase images. The data obtained were combined to create receiver operating characteristic curves, and the areas under the curves were compared. Imaging characteristics, including signal intensity, were recorded. Lesion-to-liver enhancement ratio was calculated for each contrast-enhanced phase. RESULTS: The readers' average receiver operating characteristic area was significantly higher after disclosure of hepatocyte phase images (p=0.024). FNHs were correctly diagnosed in 74.3-97.1% of cases before and 97.1-100% of cases after the disclosure of hepatocyte phase images; hepatocellular adenoma was correctly diagnosed in 83-100% and 91.7-100% of cases (p>0.05). The presence of a central scar in FNH and fat on hepatocellular adenoma were the only morphologic features that were statistically significantly different (p<0.05). FNH had greater average contrast-enhanced signal intensity and enhancement ratio in all phases (p<0.001). A hepatocyte phase enhancement ratio of less than 0.7 was 100% specific and 91.6% sensitive for hepatocellular adenoma, with accuracy of 97.1% for these data. CONCLUSION: Gadoxetate disodium-enhanced MRI had high accuracy in diagnosis of FNH and hepatocellular adenoma, and the hepatocyte phase improved their distinction. FNH enhances significantly more than hepatocellular adenoma. An enhancement ratio, particularly in the hepatocyte phase, can be potentially used as an additional distinguishing feature.