MRI features of primary rare malignancies of the liver: A report from four university centres.

PURPOSE: To determine if rare primary malignancies of the liver may have consistent features on magnetic resonance imaging (MRI). MATERIALS AND METHODS: This IRB-compliant retrospective study reviewed the records from the pathology departments of four university centres over an 11-year period from 2005-2016 to identify rare primary malignant tumours, which were cross-referenced with MRI records. MRI studies of these patients were reviewed to determine if these tumours exhibited consistent and distinctive features. RESULTS: Sixty patients were identified with rare primary liver tumours. The following distinctive features and frequency of occurrence were observed: mixed hepatocellular carcinoma-cholangiocarcinoma showed regions of wash-out in 7/19 of patients; 6/6 of fibrolamellar carcinomas demonstrated large heterogeneous lesions with large heterogeneous central scars; epithelioid haemangioendothelioma larger than 2 cm showed target-like enhancement in late-phase enhancement in 9/13; sarcomas excluding angiosarcoma had central necrosis in 3/9 and haemorrhage in 5/9; angiosarcomas showed centripedal progressive nodular enhancement in 3/6 and showed regions of haemorrhage in 3/6; and 7/7 of primary hepatic lymphomas showed encasement of vessels. CONCLUSION: Although helpful features for the differentiation of rare primary malignancies of the liver are identified, no MRI features appear to be specific and therefore histopathological confirmation is usually required for definitive diagnosis. KEY POINTS: • No MRI features appear to be specific for rare primary liver malignancies. • Haemorrhage is a helpful sign in diagnosis of primary hepatic sarcomas. • Angiosarcomas may show progressive nodular enhancement towards the centre mimicking haemangioma. • Vessel encasement is a helpful sign in diagnosis of primary hepatic lymphoma.

Magnetic resonance imaging of acute appendicitis in pregnancy: a 5-year multiinstitutional study.

OBJECTIVE: The purpose of this study was to determine the diagnostic performance of magnetic resonance imaging (MRI) in the diagnosis of acute appendicitis during pregnancy in a multiinstitutional study. STUDY DESIGN: In this multicenter retrospective study, the cases of pregnant women who underwent MRI evaluation of abdominal or pelvic pain and who had clinical suspicion of acute appendicitis between June 1, 2009, and July 31, 2014, were reviewed. All MRI examinations with positive findings for acute appendicitis were confirmed with surgical pathologic information. Sensitivity, specificity, negative predictive values, and positive predictive values were calculated. Receiver operating characteristic curves were generated, and area under the curve analysis was performed for each participating institution. RESULTS: Of the cases that were evaluated, 9.3% (66/709) had MRI findings of acute appendicitis. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive values were 96.8%, 99.2%, 99.0%, 92.4%, and 99.7%, respectively. There was no statistically significant difference between centers that were included in the study (pair-wise probability values ranged from 0.12-0.99). CONCLUSION: MRI is useful and reproducible in the diagnosis of suspected acute appendicitis during pregnancy.

Cardiac resynchronization therapy: double cannulation approach to coronary venous lead placement via a prominent thebesian valve.

We report identification of a prominent Thebesian valve by cardiovascular computed tomography (CT) angiography impeding cannulation of the coronary sinus, with subsequent successful coronary venous lead placement with cannulation of the coronary sinus ostium via a transvenous femoral vein approach and subsequent cannulation of the ostium with the coronary venous lead with a left subclavian approach. A 57-year-old man with nonischemic dilated cardiomyopathy, New York Heart Association Class III heart failure, left bundle branch block, and an ejection fraction of 15%, underwent an attempted cardiac resynchronization therapy implantable cardiac defibrillator (ICD). As the coronary sinus ostium could not be cannulated, a dual chamber ICD was placed. The patient subsequently underwent cardiovascular CT angiography, which identified a prominent Thebesian valve at the coronary sinus ostium as the anatomic obstacle to cannulation. Reattempted transvenous cardiac resynchronization therapy was accomplished successfully with a double cannulation approach: cannulation of the coronary sinus ostium with a catheter via a transvenous femoral vein approach and subsequent cannulation with the coronary venous lead via a left subclavian approach. When a prominent Thebesian valve is identified as an obstacle to transvenous left ventricular lead placement, cannulation of the coronary sinus by an alternate venous approach may allow for a coronary venous route rather than necessitate an epicardial approach.

Incremental value of color coding in 3D volume rendered CT images for interpretation of complex cardiothoracic vascular malformations.

OBJECTIVES: To evaluate the benefit of color coding of CT angiography images for the assessment of complex cardiovascular malformations by comparing the quality of 3D (dimensional) volume rendered (VR) images before and after vessel color coding. METHODS: Cardiothoracic CT images of 34 patients with complex vascular malformations were retrospectively selected for post processing. 3D VR images were created without and after color coding of the target vessels. Source images as well as selected 3D VR images without and with color coding were reviewed independently by 4 observers and scores were recorded on a 4-point scale for overall image quality, visualization conspicuity of target vessels, and final interpretation of target structures. RESULTS: Overall diagnostic advantages of color coded VR images compared with non-color coded VR images included; improved visualization of the anatomical course of vessels, improved visualization of the extent of abnormality, better understanding of the spatial relationship of structures (i.e. to right ventricle outflow tract), and improved overall quality of the images. For all comparisons the color coded score was statistically significantly better than the non-color coded score (p<0.0001). A trend showed that review speed was faster for color coded images (p=0.06). Good inter-observer agreement was achieved for the target conspicuity and final interpretation scores with weighted Kappa score of 0.66 (95% CI: 0.54, 0.79) and 0.71 (95% CI: 0.60, 0.81) respectively. CONCLUSION: Color coded 3D VR images can optimize visualization of vascular structures and improve interpretation of complex vascular malformation in cardiothoracic CT studies.

The new staging system for lung cancer: imaging and clinical implications.

Accurate staging of lung cancer is necessary to describe and communicate disease extent, predict prognosis, determine therapy, and evaluate the results of clinical trials. The Union Internationale Contre le Cancer and the American Joint Committee on Cancer published the seventh edition of tumor, node, and metastasis in lung cancer in 2009. Changes to the sixth edition have been based on the analysis of a large database of patients with lung cancer by the International Staging Committee of the International Association for the Study of Lung Cancer. This study reviews the new seventh edition of the tumor, node, and metastasis lung cancer staging system and discusses the radiologic and therapeutic implications.