Autoimmune Pancreatitis: Disease Evolution, Staging, Response Assessment, and CT Features That Predict Response to Corticosteroid Therapy

Purpose:To evaluate the evolution of morphologic features of autoimmune pancreatitis (AIP) at computed tomography (CT) and to identify imaging features that can predict AIP response to corticosteroid therapy (CST). Materials and Methods: This HIPAA-compliant retrospective study had institutional review board approval. From among a cohort of 63 Patients with AIP, 15 Patients (12 men, three women, mean age, 64.7 years, age range, 30-84 years) who underwent sequential CT examinations before treatment were included to assess the evolution of disease by reviewing pancreatic, peripancreatic, and ductal changes. Of these Patients, 13 received CST and underwent posttreatment CT, these CT studies were evaluated to determine if there were imaging features that could predict response to CST. Results: The disease evolved from changes of diffuse (14 of 15 Patients) or focal (one of 15 Patients) parenchymal swelling, peripancreatic stranding (10 of 15 Patients), halo (nine of 15 Patients), pancreatic duct changes (15 of 15 Patients), and distal common bile duct narrowing (12 of 15 Patients) to either resolution or development of ductal strictures and/or focal masslike swelling. In 13 Patients treated with CST, favorable response to treatment was seen in those with diffuse pancreatic and peripancreatic changes. Suboptimal response was seen in Patients with ductal stricture formation (two of 13 Patients) and in those in whom focal masslike swellings persisted after resolution of diffuse changes (seven of 13 Patients). Conclusion: CT features like diffuse swelling and halo respond favorably to CST and likely reflect an early inflammatory phase, whereas features like ductal strictures and focal masslike swelling are predictive of a suboptimal response and symbolize a late stage with predominance of fibrosis

Impact of an Information Technology–Enabled Initiative on the Quality of Prostate Multiparametric MRI Reports

Rationale and Objectives: Assess the impact of implementing a structured report template and a computer-aided diagnosis (CAD) tool on the quality of prostate multiparametric MRI (mp-MRI) reports. Materials and Methods: Institutional Review Board approval was obtained for this HIPAA-compliant study performed at an academic medical center. The study cohort included all prostate mp-MRI reports (n=385) finalized 6 months before and after implementation of a structured report template and a CAD tool (collectively the IT tools) integrated into the PACS workstation. Primary outcome measure was quality of prostate mp-MRI reports. An expert panel of our institution’s subspecialty trained abdominal radiologists defined prostate mp-MRI report quality as optimal, satisfactory or unsatisfactory based on documentation of 9 variables. Reports were reviewed to extract the predefined quality variables and determine whether the IT tools were used to create each report. Chi-square and Student’s t-tests were used to compare report quality before and after implementation of IT tools. Results: The overall proportion of optimal or satisfactory reports increased from 29.8% (47/158) to 53.3% (121/227) (p<0.001) after implementing the IT tools. While the proportion of optimal or satisfactory reports increased among reports generated using at least one of the IT tools (47/158=[29.8%] vs. 105/161=[65.2%]; p<0.001), there was no change in quality among reports generated without use of the IT tools (47/158=[29.8%] vs. 16/66=[24.2%]; p=0.404). Conclusion: The use of a structured template and CAD tool improved the quality of prostate mp-MRI reports compared to free-text report format and subjective measurement of contrast enhancement kinetic curve

Radiogenomics of clear cell renal cell carcinoma: preliminary findings of The Cancer Genome Atlas–Renal Cell Carcinoma (TCGA–RCC) Imaging Research Group

Purpose: To investigate associations between imaging features and mutational status of clear cell renal cell carcinoma (ccRCC). Materials and methods: This multi-institutional, multi-reader study included 103 patients (77 men; median age 59 years, range 34–79) with ccRCC examined with CT in 81 patients, MRI in 19, and both CT and MRI in three; images were downloaded from The Cancer Imaging Archive, an NCI-funded project for genome-mapping and analyses. Imaging features [size (mm), margin (well-defined or ill-defined), composition (solid or cystic), necrosis (for solid tumors: 0%, 1%–33%, 34%–66% or >66%), growth pattern (endophytic, <50% exophytic, or ≥50% exophytic), and calcification (present, absent, or indeterminate)] were reviewed independently by three readers blinded to mutational data. The association of imaging features with mutational status (VHL, BAP1, PBRM1, SETD2, KDM5C, and MUC4) was assessed. Results: Median tumor size was 49 mm (range 14–162 mm), 73 (71%) tumors had well-defined margins, 98 (95%) tumors were solid, 95 (92%) showed presence of necrosis, 46 (45%) had ≥50% exophytic component, and 18 (19.8%) had calcification. VHL (n = 52) and PBRM1 (n = 24) were the most common mutations. BAP1 mutation was associated with ill-defined margin and presence of calcification (p = 0.02 and 0.002, respectively, Pearson’s χ2 test); MUC4 mutation was associated with an exophytic growth pattern (p = 0.002, Mann–Whitney U test). Conclusions: BAP1 mutation was associated with ill-defined tumor margins and presence of calcification; MUC4 mutation was associated with exophytic growth. Given the known prognostic implications of BAP1 and MUC4 mutations, these results support using radiogenomics to aid in prognostication and management

PET/CT-guided radiofrequency and cryoablation: is tumor fluorine-18 fluorodeoxyglucose activity dissipated by thermal ablation?

PURPOSE: To determine if tumor fluorine-18 fluorodeoxyglucose ((18)F-FDG) activity is dissipated by radiofrequency (RF) ablation or cryoablation during tumor ablation guided by positron emission tomography/computed tomography (PET/CT). MATERIALS AND METHODS: This prospective study enrolled 12 patients (9 women and 3 men, 39-65 years old), each with at least one (18)F-FDG-avid liver, perihepatic, or lung tumor. Six patients (experimental group) underwent percutaneous PET/CT-guided RF ablation (n = 3) or cryoablation (n = 3). Six patients (control group) underwent diagnostic PET/CT-guided percutaneous biopsy. At a mean time of 103.5 minutes after a single intravenous (18)F-FDG dose, preprocedure and postprocedure PET/CT scans, separated by a mean time interval of 83.4 minutes, were obtained in all patients. Target tumor maximum standardized uptake value (TSUVmax) and ratio (SUVratio) of TSUVmax to normal liver average standardized uptake value (LSUVavg) were measured on all scans. Percentage changes in TSUVmax and SUVratio from preprocedure to postprocedure scans were compared for both groups and analyzed using the Student t test (P \u3c .05 considered statistically significant). RESULTS: For all patients in both groups, TSUVmax and SUVratio increased from preprocedure to postprocedure PET/CT scans without statistically significant differences. The mean percentage increase in TSUVmax for the ablation group was 32.5% (range 8.2%-46.7%) and for the biopsy group was 24.6% (3.7%-42.4%; P = .45). The mean percentage increase in SUVratio for the ablation group was 47.9% (18.8%-69.6%) and for the biopsy group was 37.6% (9.4%-65%; P = .37). CONCLUSIONS: Tumor (18)F-FDG activity is not dissipated by percutaneous RF ablation or cryoablation. When performing (18)F-FDG PET/CT-guided RF ablation or cryoablation, changes in target tumor (18)F-FDG activity cannot be used to monitor treatment effects

Successful percutaneous radiologic management of renal cell carcinoma tumor seeding caused by percutaneous biopsy performed before ablation.

A case is reported of the successful image-based detection, diagnosis, and percutaneous ablation of tumor seeding in a 61-year-old man that was caused by percutaneous biopsy of a renal cell carcinoma performed before cryoablation and was not detected until 4 years after the biopsy procedure. Although tumor seeding is a rare complication after percutaneous biopsy or ablation, this case emphasizes the importance of imaging surveillance of the needle tract used during both biopsy and ablation procedures, provides guidance on measures that can be used to minimize the occurrence of tumor seeding, and demonstrates that entirely radiologic management can be successful

IgG4-associated cholangitis: a comparative histological and immunophenotypic study with primary sclerosing cholangitis on liver biopsy material

IgG4-associated cholangitis is a steroid-responsive hepatobiliary inflammatory condition associated with autoimmune pancreatitis that clinically and radiologically mimics primary sclerosing cholangitis. In this study, we conducted a morphological and immunohistochemical analysis of liver material obtained from individuals with IgG4-associated cholangitis, and compared these with well-characterized cases of primary sclerosing cholangitis. The study group consisted of 10 patients (9 biopsy and 1 hepatectomy case) with IgG4-associated cholangitis and 17 patients with primary sclerosing cholangitis (16 needle biopsy and 1 hepatectomy case). All patients with IgG4-associated cholangitis had pancreatic involvement as well, and six pancreatectomy samples revealed characteristic histopathological features of autoimmune pancreatitis. Primary sclerosing cholangitis cases were defined by the presence of a characteristic ERCP appearance. Clinical, pathological, radiological, and follow-up data were recorded for all cases. Portal and periportal inflammation was graded according to Ishak's guidelines. Immunohistochemical stains for IgG and IgG4 were performed. The cohort of patients with IgG4-associated cholangitis (mean age: 63 years) was older than individuals with primary sclerosing cholangitis (mean age: 44 years). Seven of these cases showed intrahepatic biliary strictures. IgG4-associated cholangitis liver samples showed higher portal (P=0.06) and lobular (P=0.009) inflammatory scores. Microscopic portal-based fibro-inflammatory nodules that were composed of fibroblasts, plasma cells, lymphocytes, and eosinophils were exclusively observed in five of the IgG4-associated cholangitis cases (50%). More than 10 IgG4-positive plasma cells per HPF (high power field) were observed in 6 of the IgG4-associated cholangitis cases (mean: 60, range: 0–140 per HPF), whereas all primary sclerosing cholangitis cases showed significantly lesser numbers (mean: 0.08, range: 0–1 per HPF). On a liver biopsy, the histological features of IgG4-associated cholangitis may be distinctive, and in conjunction with IgG4 immunohistochemical stain, may help distinguish this disease from primary sclerosing cholangitis

IgG4-associated cholangitis: a comparative histological and immunophenotypic study with primary sclerosing cholangitis on liver biopsy material

IgG4-associated cholangitis is a steroid-responsive hepatobiliary inflammatory condition associated with autoimmune pancreatitis that clinically and radiologically mimics primary sclerosing cholangitis. In this study, we conducted a morphological and immunohistochemical analysis of liver material obtained from individuals with IgG4-associated cholangitis, and compared these with well-characterized cases of primary sclerosing cholangitis. The study group consisted of 10 patients (9 biopsy and 1 hepatectomy case) with IgG4-associated cholangitis and 17 patients with primary sclerosing cholangitis (16 needle biopsy and 1 hepatectomy case). All patients with IgG4-associated cholangitis had pancreatic involvement as well, and six pancreatectomy samples revealed characteristic histopathological features of autoimmune pancreatitis. Primary sclerosing cholangitis cases were defined by the presence of a characteristic ERCP appearance. Clinical, pathological, radiological, and follow-up data were recorded for all cases. Portal and periportal inflammation was graded according to Ishak's guidelines. Immunohistochemical stains for IgG and IgG4 were performed. The cohort of patients with IgG4-associated cholangitis (mean age: 63 years) was older than individuals with primary sclerosing cholangitis (mean age: 44 years). Seven of these cases showed intrahepatic biliary strictures. IgG4-associated cholangitis liver samples showed higher portal (P=0.06) and lobular (P=0.009) inflammatory scores. Microscopic portal-based fibro-inflammatory nodules that were composed of fibroblasts, plasma cells, lymphocytes, and eosinophils were exclusively observed in five of the IgG4-associated cholangitis cases (50%). More than 10 IgG4-positive plasma cells per HPF (high power field) were observed in 6 of the IgG4-associated cholangitis cases (mean: 60, range: 0-140 per HPF), whereas all primary sclerosing cholangitis cases showed significantly lesser numbers (mean: 0.08, range: 0-1 per HPF). On a liver biopsy, the histological features of IgG4-associated cholangitis may be distinctive, and in conjunction with IgG4 immunohistochemical stain, may help distinguish this disease from primary sclerosing cholangitis