To develop an optimized interpretation strategy of dynamic contrast enhanced breast MRI based on a combination of quantitative and qualitative criteria, the features of 120 histopathologically verified lesions were retrospectively analysed on contrast enhanced dynamically acquired (before and 1, 2, 4 and 7 min following injection of 0.2 mmol kg-1 gadolinium-DOTA) three-dimensional gradient echo images. Quantitative criteria, based on relative signal intensity measurements and qualitative morphological features, including lesion shape, margins and enhancement patterns were analysed in regard to differentiating malignant (n = 70) from benign (n = 50) lesions. Quantitative assessment of enhancement profiles was most accurate when analysis was based on early 1 min measurements. Using a 90% threshold, sensitivity and specificity in detecting breast cancer were 83% and 66%, respectively. When based on qualitative morphological analysis alone, sensitivity and specificity were 83% and 54%. Combined quantitative and qualitative assessment yielded a considerably higher sensitivity, specificity and accuracy of 93%, 74% and 85%, respectively. In conclusion, results from dynamic contrast enhanced breast MRI can be improved by basing the interpretation on both quantitative and qualitative criteria.

The in vivo use of an MR-tracking PTA catheter is safe under most scanning conditions.

Purpose: To develop a technique for dynamic magnetic resonance imaging (MRI) of joint motion based on a combination of real-time TrueFISP (fast imaging with steady state precession) imaging with surface radiofrequency (RF) coils. Materials and Methods:The metacarpal, elbow, tarsal, and knee joint of five volunteers and the knees of four patients were examined with a real-time TrueFISP sequence during movement of the joints.Results: All examined joints could be assessed under dynamic conditions with high image contrast and high temporal resolution.Conclusion: Dynamic MRI of joints with TrueFISP is feasible and can provide information supplemental to static joint examinations.

Purpose:To prove the feasibility of air-distended magnetic resonance colonography (MRC) and compare it with waterbased distention. Materials and Methods:In five volunteers, the colon was imaged twice: once after distending the colon with air and a second time after distending the colon with water. A total of 50 patients, who had been referred to colonoscopy for a suspected colorectal pathology were randomized into water-distention (N ϭ 25) and air-distention (N ϭ 25) groups. A contrast-enhanced T1-weighted three-dimensional volume interpolated breath-hold (VIBE) sequence was collected. Comparative analysis was based on qualitative ratings of image quality and bowel distention, as well as contrast-to-noise ratio (CNR) measurements for the colonic wall with respect to the colonic lumen. In addition, patient acceptance was evaluated.Results: Inflammatory changes and colorectal masses were correctly identified on MRC in eight patients each. One 4-mm polyp identified at colonoscopy was missed on waterdistended MRC. There were no false positive findings. No significant differences were found between air-and waterdistention regarding discomfort levels and image quality. The presence of air in the colonic lumen was not associated with susceptibility artifacts. CNR of the contrast-enhanced colonic wall, as well as bowel distention, were superior on air-distended three-dimensional data sets. Conclusion:MRC can be performed using either water or air for colonic distention. Both techniques permit assessment of the colonic wall and identification of colorectal masses. While discomfort levels are similar for both agents, MRC with air provides higher CNR and better colonic distention. MAGNETIC RESONANCE (MR) colonography (MRC) has been shown to be an appropriate diagnostic tool for the detection of pathologies, including colorectal masses, diverticula, and inflammatory disease (1-4). Reliable assessment of the colon by means of MR imaging is predicated upon the fulfillment of two requirements: sufficient distention of the colonic lumen and sufficient contrast between the colonic lumen and pathologies arising from the colonic wall. Hence, the cleansed colon is filled either with liquid, such as tap water, with or without the addition of paramagnetic contrast (2,5,6), or gaseous agents, such as room air, CO 2 , and hyperpolarized helium (7-9). While initial experience was based on techniques rendering the colonic lumen bright, dark lumen MRC has recently been found to be advantageous (1,3).The fear of compromised image quality due to susceptibility effects at air/tissue interfaces has long favored the use of water or water-based solutions for colonic distention in MRC (6,10). With the availability of high performance gradients permitting data acquisition with very short echo times, the potential of relevant susceptibility effects is reduced. Accordingly, interest in the use of gaseous agents has grown. They avoid the risk of spillage and have been suggested to be associated with less discomfort compared to fluid (7,8).The purpos...

Our whole-body PET-CT protocol provided good vascular and intestinal enhancement without compromising PET quality, leading to a potential improvement in the diagnostic capacity of the combined PET-CT examination.