CT and MRI appearances of cardiac pseudotumours.

Cardiac anatomic variants, vascular abnormalities and non-neoplastic mass lesions may be misinterpreted as tumours, potentially leading to inappropriate intervention. This article discusses the complementary role of multi-detector computed tomography and magnetic resonance imaging in the work-up of suspected masses. The cross-sectional imaging appearance of common or distinctive anatomic variants and pseudotumours, including 'don't touch' lesions, are reviewed.

Clinical and Technical Aspects of MR-Guided High Intensity Focused Ultrasound for Treatment of Symptomatic Uterine Fibroids.

Although many women undergo hysterectomy for treatment of uterine fibroids, there are more options than ever before for fibroid treatment. A combination of objective criteria, including clinical parameters, anatomic factors, fibroid characteristics, and patient desires influence the choice of optimal therapeutic modality for a woman with symptomatic uterine fibroids. Magnetic resonance imaging-guided high intensity focused ultrasound (MR-HIFU) is the only noninvasive treatment option for women with symptomatic uterine fibroids unresponsive to medical treatment. The procedure has been shown to be safe and effective. MR-HIFU couples the three-dimensional multiplanar anatomic imaging and thermal monitoring capability of MR imaging with the therapeutic thermal-based coagulative necrosis mechanism of HIFU to safely and effectively ablate limited volume classical fibroids. In the author's experience, a multidisciplinary fibroid clinic facilitates a unified approach between gynecologists, radiologists, and others to individualize the most appropriate fibroid treatment options for each woman. This article describes the MR-HIFU technique and outcomes, as well as patient selection and treatment assessment.

T1 hyperintense renal lesions: characterization with diffusion-weighted MR imaging versus contrast-enhanced MR imaging.

PURPOSE: To compare the performance of apparent diffusion coefficient (ADC) measurement obtained with diffusion-weighted (DW) magnetic resonance (MR) imaging in the characterization of non-fat-containing T1 hyperintense renal lesions with that of contrast material-enhanced MR imaging, with histopathologic analysis and follow-up imaging as the reference standards. MATERIALS AND METHODS: Institutional review board approval was obtained for this HIPAA-compliant retrospective study, and the informed consent requirement was waived. Two independent observers retrospectively assessed MR images obtained in 41 patients with non-fat-containing T1 hyperintense renal lesions. The MR examination included acquisition of DW and contrast-enhanced T1-weighted images. For each index lesion, the observers assessed the (a) mean (+/- standard deviation) of ADC, (b) enhancement ratio, and (c) subtracted images for the presence of enhancement (confidence score, 1-5). Histopathologic analysis of renal cell carcinomas (RCCs) and follow-up imaging for benign lesions were the reference standards. ADCs of benign lesions and RCCs were compared. Receiver operating characteristic (ROC) curve analysis was performed to assess the accuracy of DW imaging, enhancement ratio, and subtraction for the diagnosis of RCC. RESULTS: A total of 64 lesions (mean diameter, 3.9 cm), including 38 benign T1 hyperintense cysts and 26 RCCs, were assessed. Mean ADCs of RCCs were significantly lower than those of benign cysts ([1.75 +/- 0.57] x 10(-3) mm(2)/sec vs [2.50 +/- 0.53] x 10(-3) mm(2)/sec, P < .0001). ADCs of solid and cystic portions of complex cystic RCCs were significantly different ([1.37 +/- 0.55] x 10(-3) mm(2)/sec vs [2.45 +/- 0.63] x 10(-3) mm(2)/sec, P < .0001). When data from both observers were pooled, area under the ROC curve, sensitivity, and specificity were 0.846, 71%, and 91%, respectively, for DW imaging; 0.865, 65%, and 96%, respectively, for enhancement ratio (at the excretory phase); and 0.861, 83%, and 89%, respectively, for subtraction (P = .48 and P = .85, respectively). The combination of DW imaging and subtraction resulted in area under the ROC curve, sensitivity, and specificity of 0.893, 87%, and 92%, respectively, with significantly improved reader confidence compared with subtraction alone (P = .041). CONCLUSION: The performance of DW imaging was equivalent to that of enhancement ratio in the characterization of T1 hyperintense renal lesions, with both methods having lower sensitivity than image subtraction without reaching significance.