Evaluation of the urinary bladder using three-dimensional CT cinematic rendering.

Three-dimensional (3D) visualizations of volumetric data from computed tomography (CT) acquisitions can be important adjuncts to interpretation of two-dimensional (2D) reconstructions. Recently, the 3D technique known as cinematic rendering (CR) was introduced, allowing photorealistic images to be created from standard CT acquisitions. CR methodology is under increasing investigation for use in the display of regions of complex anatomy and as a tool for education and preoperative planning. In this article, we will illustrate the potential utility of CR for evaluating the urinary bladder and associated pathology. The urinary bladder is susceptible to a multitude of neoplastic and inflammatory conditions and their sequelae. The intrinsic properties of CR may prove useful for the display of subtle mucosal/luminal irregularities, the simultaneous display of soft tissue detail with high-resolution maps of associated tumor neovasculature, and the improved display of spatial relationships to aid pre-procedural planning. Further refinement of presets for CR image creation and prospective evaluation of urinary bladder CR in real-world settings will be important for widespread clinical adoption.

Differentiating autoimmune pancreatitis from pancreatic ductal adenocarcinoma with CT radiomics features.

PURPOSE: The purpose of this study was to determine whether computed tomography (CT)-based machine learning of radiomics features could help distinguish autoimmune pancreatitis (AIP) from pancreatic ductal adenocarcinoma (PDAC). MATERIALS AND METHODS: Eighty-nine patients with AIP (65 men, 24 women; mean age, 59.7±13.9 [SD] years; range: 21-83 years) and 93 patients with PDAC (68 men, 25 women; mean age, 60.1±12.3 [SD] years; range: 36-86 years) were retrospectively included. All patients had dedicated dual-phase pancreatic protocol CT between 2004 and 2018. Thin-slice images (0.75/0.5mm thickness/increment) were compared with thick-slices images (3 or 5mm thickness/increment). Pancreatic regions involved by PDAC or AIP (areas of enlargement, altered enhancement, effacement of pancreatic duct) as well as uninvolved parenchyma were segmented as three-dimensional volumes. Four hundred and thirty-one radiomics features were extracted and a random forest was used to distinguish AIP from PDAC. CT data of 60 AIP and 60 PDAC patients were used for training and those of 29 AIP and 33 PDAC independent patients were used for testing. RESULTS: The pancreas was diffusely involved in 37 (37/89; 41.6%) patients with AIP and not diffusely in 52 (52/89; 58.4%) patients. Using machine learning, 95.2% (59/62; 95% confidence interval [CI]: 89.8-100%), 83.9% (52:67; 95% CI: 74.7-93.0%) and 77.4% (48/62; 95% CI: 67.0-87.8%) of the 62 test patients were correctly classified as either having PDAC or AIP with thin-slice venous phase, thin-slice arterial phase, and thick-slice venous phase CT, respectively. Three of the 29 patients with AIP (3/29; 10.3%) were incorrectly classified as having PDAC but all 33 patients with PDAC (33/33; 100%) were correctly classified with thin-slice venous phase with 89.7% sensitivity (26/29; 95% CI: 78.6-100%) and 100% specificity (33/33; 95% CI: 93-100%) for the diagnosis of AIP, 95.2% accuracy (59/62; 95% CI: 89.8-100%) and area under the curve of 0.975 (95% CI: 0.936-1.0). CONCLUSIONS: Radiomic features help differentiate AIP from PDAC with an overall accuracy of 95.2%.

Cinematic rendering of focal liver masses.

Cinematic rendering (CR) is a recently described three-dimensional (3D) rendering technique that generates photorealistic images based on a new lighting model. This review illustrates the potential application of CR in the evaluation of focal liver masses. CR shows promise in improving the visualization of enhancement pattern and internal architecture, local tumor extension, and global disease burden, which may be helpful in focal liver mass characterization and pretreatment planning.

3D CT cinematic rendering of the spleen: Potential role in problem solving.

Cinematic rendering (CR) is a new 3D visualization methodology for volumetric diagnostic imaging including computed tomography (CT) datasets composed of isotropic voxels. CR produces photorealistic images with enhanced detail relative to other 3D visualization methods and realistic shadowing. In this review, we provide a number of examples of splenic pathology visualized with CR including conditions affecting the splenic vasculature, neoplasms, and accessory spleens. These examples are compared to 2D CT and traditional 3D CT techniques and the potential advantages of CR are highlighted. CR displays textural changes in the splenic parenchyma to particular advantage, and a portion of this review will be devoted to examples of how textural features can help distinguish intrapancreatic accessory spleens from neuroendocrine tumors.

The many faces of pancreatic serous cystadenoma: Radiologic and pathologic correlation.

Pancreatic serous cystadenoma can be categorized into microcystic, honeycomb, oligocystic, and solid patterns based on imaging appearance. The presence of typical computed tomography (CT) features helps to differentiate serous cystadenomas from other cystic and solid pancreatic masses. Cases with atypical features present a diagnostic challenge as they can mimic malignant neoplasms. This article reviews pathophysiology, prevalence, CT features, mimickers and recommendations for management of pancreatic serous cystadenoma.

Imaging features of rare pancreatic tumors.

The increasing use of abdominal imaging has led to a growing incidence of traditionally uncommon pancreatic tumors. These rare tumors have specific imaging features whose knowledge may heighten confidence in characterization and may avoid unnecessary surgical procedures when imaging findings suggest a benign condition. Computed tomography (CT) is the modality with which rare pancreatic tumors are incidentally detected in the majority of cases. Magnetic resonance imaging (MRI) is often performed as a second line examination for further characterization. This review provides an update on CT and MRI findings of rare tumors of the pancreas.

Extra-intestinal malignancies in inflammatory bowel diseases: An update with emphasis on MDCT and MR imaging features.

Inflammatory bowel diseases (IBD) are associated with an increased risk of gastrointestinal cancers and more specifically in sites affected by chronic inflammation. However, patients with IBD have also an increased risk for developing a variety of extra-intestinal cancers. In this regard, hepatobiliary cancers, such as cholangiocarcinoma, are more frequently observed in IBD patients because of a high prevalence of primary sclerosing cholangitis, which is considered as a favoring condition. Extra-intestinal lymphomas, mostly non-Hodgkin lymphomas, and skin cancers are also observed with an increased incidence in IBD patients by comparison with that in patients without IBD. This review provides an update on demographics, risk factors and clinical features of extra-intestinal malignancies, including cholangiocarcinoma, hepatocellular carcinoma and lymphoma, that occur in patients with IBD along with a special emphasis on the multidetector row computed tomography and magnetic resonance imaging features of these uncommon conditions.

MDCT of acute colitis in adults: an update in current imaging features.

Acute colitis is often diagnosed on multidetector row computed tomography (MDCT) because patients with this condition present with abdominal pain and a variety of nonspecific symptoms. Acute colitis has multiple causes with varying degrees of severity. Analysis of the extent of colonic involvement, presence of specific MDCT imaging features and associated signs should help radiologist narrow the diagnosis. Integrating the results of clinical examination and biological tests is mandatory, and in case of ambiguous or nonspecific MDCT findings, endoscopy and colon biopsy should always be considered for a definite diagnosis. The purpose of this review is to discuss and illustrate MDCT features that are helpful for characterizing acute colitis in adults and to provide an update in current MDCT features.

Advanced imaging of skeletal manifestations of systemic mastocytosis.

Systemic mastocytosis comprises a group of clonal disorders of the mast cell that most commonly involves the skeletal system. Imaging can be helpful in the detection and characterization of the osseous manifestations of this disease. While radiography and bone scans are frequently used for this assessment, low-dose multidetector computed tomography and magnetic resonance imaging can be more sensitive for the detection of marrow involvement and for the demonstration of the various disease patterns. In this article, we review the pathophysiological and clinical features of systemic mastocytosis, discuss the role of imaging for staging and management, and illustrate the various cross-sectional imaging appearances. Awareness and knowledge of the imaging features of this disorder will increase the accuracy of image interpretation and can contribute important information for management decisions.

Serum IL-6 levels are associated with significant coronary stenosis in cardiovascularly asymptomatic inner-city black adults in the US.

OBJECTIVES AND DESIGN: The objective of this study was to explore whether increased levels of inflammatory cytokines are associated with the risk of clinically silent coronary artery disease. SUBJECTS: Three-hundred-fifty-six black adults aged 25-54 residing in inner city of Baltimore, Maryland, United States were included in this study. METHODS: Sociodemographics were assessed as were lipid profiles, IL-6, tumor necrosis factor-alpha (TNF-alpha), soluble intercellular adhesion molecule-1 (sICAM-1), and high-sensitivity C-reactive protein (hs-CRP) levels. Computed tomography (CT) coronary angiography was performed. RESULTS: Coronary calcification was identified in 22.5 % participants and 14 % had significant (>or=50 %) coronary stenosis. Multiple logistic regression analyses suggested that IL-6 levels were independently associated with the presence of coronary calcification and significant coronary stenosis, while TNF-alpha, sICAM-1 and hs-CRP levels were not. CONCLUSIONS: This study underscores a critical role for IL-6 in atherosclerosis and suggests that IL-6 may be a marker for significant coronary stenosis in cardiovascularly asymptomatic individuals.

What are radiologists doing to prevent contrast-induced nephropathy (CIN) compared with measures supported by current evidence? A survey of European radiologists on CIN associated with computed tomography.

BACKGROUND: Contrast-induced nephropathy (CIN) is a serious complication of the use of iodinated contrast media (CM), and is associated with increased morbidity and mortality. PURPOSE: To investigate whether radiologists take sufficient measures to prevent CIN in computed tomography (CT). MATERIAL AND METHODS: 2005 survey of 509 European radiologists who had > or =3 years' experience and performed > or =50 CT scans/week. RESULTS: The most common methods used to identify patients at risk of CIN were renal function measurements (64%), clinical judgment (55%), and patient questionnaires (31%); 9% made no routine attempt to identify at-risk patients. The most common preventive protocols used in at-risk patients included: intravenous (i.v.) saline volume repletion (59%) or oral hydration (52%) before/after CT; use of low-osmolar CM (LOCM; 40%) or isosmolar CM (IOCM; 36%); and N-acetylcysteine (20%); 8% used no hydration regimen. While 78% of respondents used < or =100 ml of CM in high-risk patients, 14% used < or =150 ml, and 9% set no volume limit. For 57% of respondents, osmolality was the most important attribute in choosing an iodinated CM in at-risk patients; 41% agreed that CIN risk is lower with IOCM versus LOCM (31% disagreed). CONCLUSION: A European radiologist survey identified a need for increased implementation of evidence-based protocols to improve CIN prevention: routine identification of at-risk patients; withdrawal of nephrotoxic drugs; use of volume repletion regimens; lowest possible volume of CM; and appropriate CM.

MDCT angiography of living laparoscopic renal donors.

Laparoscopic donor nephrectomy has become the accepted method of harvesting the kidney at many institutions because of multiple advantages over open donor nephrectomy. Spiral computed tomographic (CT) angiography provides accurate information of renal vascular anatomy and has become an accepted method of preoperative evaluation of potential laparoscopic renal donors. More recently, multidetector CT (MDCT) provides more detailed datasets compared with single-detector spiral CT and has been used for preoperative evaluation of laparoscopic donor nephrectomy to provide accurate anatomic information. MDCT (especially 16- and 64-slice MDCT) angiography has advantages over single-detector helical CT due to rapid scan time that allows coverage of a large volume of interest with higher spatial and temporal resolutions. In this article, we review the current status of MDCT angiography in the evaluation of laparoscopic renal donors and potential advantages of using this technology.

Aortic valve calcification in systemic lupus erythematosus.

Aortic valve calcification is associated with atherosclerosis in the general population. We investigated the prevalence of and associates of aortic valve calcification in systemic lupus erythematosus (SLE). One-hundred and ninety-nine SLE patients enrolled in a clinical trial had aortic valve calcification assessed by helical CT. The patients had a mean age of 44.3 +/- 11.4 years and were 92% female, 61% Caucasian, 34% African-American, 2% Asian and 2% Hispanic. Aortic valve calcification was present in 1.5%, whereas coronary calcium was found in 43% and carotid plaque in 17%. Among cardiovascular risk factors, hs-CRP (P = 0.0592), fibrinogen (P = 0.0507), and lipoprotein(a) (P = 0.0250), were associated with aortic valve calcification. Prednisone use (P = 0.049) and use of methotrexate (P = 0.0174) were also associated with aortic valve calcification. Aortic valve calcification was associated with antiphospholipid antibody positivity (0.0287) (lupus anticoagulant, by dilute Russell viper venom time). It was not associated with coronary calcium or carotid plaque. Aortic valve calcification, although rare in SLE, was associated with some novel cardiovascular risk factors and with a marker of hypercoagulability (lupus anticoagulant). In contrast to the general population, aortic valve calcification in SLE is not associated with subclinical measures of atherosclerosis, such as coronary calcium or carotid plaque.

PET-CT detection of abdominal recurrence of ovarian cancer: radiologic-surgical correlation.

The diagnosis of recurrent ovarian cancer can be difficult on cross-sectional imaging, and variable sensitivities and specificities have been reported for positron emission tomography (PET). Combined functional and anatomic imaging with PET plus computed tomography (CT) potentially allows for improved detection of tumor masses. We investigated the sensitivity, specificity, and accuracy of PET-CT for the diagnosis of recurrent ovarian cancer. Sixteen women with previously treated ovarian cancer underwent imaging on a combined PET-CT scanner followed by surgery to assess for possible recurrent disease. The fused PET-CT images were retrospectively reviewed for recurrent disease, and the results of PET-CT were compared with the operative notes. Eleven of the 16 patients had recurrent disease at surgery. The sensitivity, specificity, and accuracy of PET-CT for disease detection on a per-patient basis were 72.7%, 40%, and 62.5%, respectively. For cases of malignant adenopathy (n = 7), 100% were detected on PET-CT. For peritoneal lesions no larger than 1 cm (n = 23), 13% were detected on PET-CT. For peritoneal lesions larger than 1 cm (n = 8), 50% were detected on PET-CT. The sensitivity of PET-CT for recurrent ovarian cancer is moderate in patients with low volume disease. A trial involving a larger number of patients with a spectrum of disease volumes is necessary to determine the impact of PET-CT in clinical practice.

Imaging of neuroendocrine tumors: accuracy of helical CT versus SRS.

BACKGROUND: We retrospectively compared the accuracy of somatostatin receptor scintigraphy (SRS) with that of helical computed tomography (CT) in the detection and localization of primary and metastatic neuroendocrine tumors. METHODS: A medical record search identified 27 patients with known or clinically suspected neuroendocrine tumors who underwent helical CT and SRS within 3 months of one another at our institution. CT images were evaluated retrospectively by two blinded radiologists who used consensus reading. Images were evaluated for the presence or absence of primary tumor and hepatic and extrahepatic metastases. CT results were compared with the SRS report as interpreted by the nuclear medicine physicians. The results of the surgical, clinical follow-up, and pathologic findings were considered as the gold standard. Sensitivity, specificity, and accuracy were calculated for both imaging techniques. In addition, McNemar analysis was performed to determine statistically significant differences between CT and SRS. RESULTS: Helical CT was more sensitive than SRS in the detection of extrahepatic metastases, and the difference between the two imaging modalities was statistically significant (p = 0.0312) as determined by the McNemar chi-square test. However, the difference between CT and SRS in detecting primary neuroendocrine tumors, hepatic metastasis, and combined hepatic and extrahepatic metastasis was not statistically significant (p = 0.625, 1.000, and 1.000, respectively). CONCLUSION: Helical CT and SRS have similar sensitivity, specificity, and accuracy in detecting primary neuroendocrine tumor and hepatic metastasis. However, helical CT appears to be more sensitive in detecting extrahepatic metastasis from primary neuroendocrine tumors.

Incremental value of CT in PET/CT of patients with colorectal carcinoma.

BACKGROUND: We assessed the contribution of dedicated computed tomographic (CT) interpretation to the accuracy of positron emission tomography (PET) plus CT in imaging patients with suspected primary or metastatic colorectal carcinoma. METHODS: One hundred PET/CT scans in 90 consecutive patients were evaluated retrospectively. Imaging was performed on a GE Discovery LS PET/CT scanner. PET images were obtained from the skull base through the midthigh after intravenous administration of 15 to 20 mCi of [(18)F] fluorine-18-fluoro-2-deoxyglucose. Noncontrast axial CT images were obtained at the same anatomic locations, with 140 kV, 80 mA, 0.8 s/CT rotation, a pitch of 6, and a table speed of 22.5 mm/s. The CT component of the PET/CT study was reviewed independently by consensus of two blinded readers. Scans were evaluated for the presence of primary disease, local recurrence, and distant metastases. Results were compared with the PET/CT report. The gold standard was clinical and imaging follow-up for at least 6 months, surgery, or biopsy. RESULTS: The study included 40 males and 50 females, with a mean age of 63 years (range, 31-92 years). The indications for the examination were to evaluate for recurrence of colorectal cancer in 83 cases, determine disease spread in 15 cases, and evaluate for possible primary malignancy in two cases with rising carcinoembryonic antigen. Sensitivity, specificity, and accuracy of the PET/CT report and of the combined PET/CT with dedicated CT interpretation were 0.914, 0.633, and 0.830 and 0.986, 1.000, and 0.980, respectively. The difference between PET/CT and the combined PET/CT with dedicated CT interpretation with respect to accuracy was statistically significant (p < 0.05). CONCLUSION: The CT portion of PET/CT provides valuable anatomic and pathologic information to the functional information provided by PET and helps improve the overall accuracy of the combined study.