Christopher P. Coppa

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.

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.

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 cm3 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.

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.

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.

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.

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.

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.

Imaging in Cirrhotic Patients Undergoing Surgical Procedures

Preoperative imaging plays an important role in cirrhotic patients undergoing surgery. The imaging may make an initial diagnosis of cirrhosis in a patient with no known history of liver disease and demonstrate findings of advanced liver disease, such as ascites, splenomegaly, and portosystemic collateral pathways. In both scenarios, the identification of cirrhosis and complications is important in the preoperative setting, since cirrhotic patients have increased risk of surgical complications. In this chapter, we will discuss the imaging findings used to make the radiographic diagnosis of cirrhosis. Extrahepatic manifestations of cirrhosis will also be reviewed with an emphasis on portal hypertension and portosystemic collaterals. Further, the clinical implication of some of these findings will be touched upon.

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.