MRI is a sensitive method for detecting invasive breast cancer, but it lacks specificity. To examine the effect of combining PET with MRI on breast lesion characterization, a prototype positioning device was fabricated to allow PET scans to be acquired in the same position as MRI scans-that is, prone. Methods: To test the hypothesis that fusion of 18 F-FDG PET and MRI scans improves detection of breast cancer, 23 patients with suspected recurrent or new breast cancer underwent a routine whole-body PET scan, a prone PET scan of the chest, and a routine breast MRI scan. The attenuation-corrected prone PET and MRI datasets were registered twice by different operators. The fusion results were judged for quality by visual inspection and statistical analysis. A joint reading of the MRI and PET scans side by side and integrated images was performed by a nuclear medicine physician and a radiologist. Sensitivity and specificity of MRI and combined MRI and PET scans were calculated on the basis of pathology reports or at least 1 y of clinical and radiologic follow-up. Results: All fusions were verified to be well matched using specific anatomic criteria. A total of 45 lesions was assessed. Lesion size range was 0.6 to 10.0 cm. Of the 44 breasts examined, 29 were suspicious for cancer, of which 15 were found to be positive on surgical excision. In lesion-by-lesion analysis, sensitivity and specificity of MRI alone were 92% and 52%, respectively; after MRI and PET fusion, they were 63% and 95%, respectively. The positive predictive value and the negative predictive value for MRI alone were 69% and 85%, respectively; after MRI and PET fusion, they were 94% and 69%, respectively. Conclusion: Acquisition of prone PET scans using the new positioning device permitted acquisition of prone scans suitable for fusion with breast MRI scans. Fused PET and MRI scans increased the specificity of MRI but decreased the sensitivity in this small group of patients. Additional data are needed to confirm the statistical significance of these preliminary findings.

Radiologists interpreting bedside chest radiographs of ICU patients detect large pleural effusions 92% of the time and can exclude large effusions with high confidence. However, small and medium effusions often are misdiagnosed as parenchymal opacities (45%) or are not seen (55%). Pulmonary opacities often are missed (34%) but are rarely misdiagnosed as pleural effusions (7%).

Purpose:To compare magnetic resonance cholangiography (MRC) with endoscopic retrograde cholangiography (ERC) in quantitatively evaluating biliary strictures in liver transplant recipients. Materials and Methods:Eight liver transplant recipients with suspected biliary complications were referred for ERC and also underwent MRC within 24 hours using a combination of single-shot rapid acquisition with relaxation enhancement (SS-RARE) and three-dimensional (3D)-RARE sequences. The studies were independently interpreted by two blinded radiologists and a single blinded endoscopist who recorded the presence of a stricture and/or upstream dilatation, the ratio of recipient-to-donor duct diameters at the anastomosis, as well as the proximal duct diameter, length, and percent stenosis of any stricture detected.Results: Using ERC as the standard of reference, MRC had a sensitivity and negative predictive value of 100%, mean specificity of 83.3%, and mean positive predictive value of 92.9% in the detection of six strictures. Compared with ERC, MRC obtained accurate measurements of recipientto-donor duct diameter ratios (r, 0.91; P Ͻ 0.01), proximal duct diameters (r, 0.83, P Ͻ 0.05), stricture lengths (r, 0.58; P ϭ 0.06), and percent stenosis (r, 0.78; P ϭ 0.06). Conclusion:MRC can provide equivalent imaging to ERC and can reliably identify and quantitatively evaluate biliary strictures in post-orthotopic liver transplantation (OLT) patients.

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