Increased spatial resolution significantly improves diagnostic confidence and accuracy at dynamic MR imaging, even if this improvement occurs at the expense of temporal resolution. Loss of kinetic information regarding enhancement rates proved to be not diagnostically relevant because enhancement rates showed broad overlap between benign and malignant lesions and were therefore of only limited diagnostic use in the individual patient. Kinetic information regarding time course pattern was preserved and confirmed as having high specificity and high positive predictive value.

Initial experiences indicate that contrast-enhanced MR imaging at 3.0 T is nearing readiness for clinical use.

MR imaging--guided large-core stereotactic breast biopsy is sufficiently accurate for obtaining histologic proof of lesions visible only at MR imaging. It can change patient treatment by reducing unnecessary surgical biopsy and can enable one-step surgery for breast cancers.

The purpose of this study was to evaluate the feasibility of high-field magnetic resonance imaging (MRI) of the lung using a T2-weighted fast-spin echo (TSE) sequence. Comparison was made with helical computed tomography CT findings in patients with diffuse pulmonary diseases. Prospective segment-wise analysis of high-field MR imaging findings in 15 patients with diffuse pulmonary diseases was made using helical CT and HRCT as the standard of reference. The MR studies were performed on a 3.0-T whole body system (Intera 3T, Philips Medical Systems) using a T2w TSE sequence with respiratory and cardiac gating (TE 80 ms TR 1,500-2,500 ms; turbo factor 17; 22 slices with 7/2-mm slice thickness and gap; 256x192 matrix). MR artifacts were graded on a three-point scale (low, moderate, high). Lung MR studies were prospectively analyzed segment-by-segment and diagnosed as healthy or pathological; results were compared with helical CT findings. In all 15 patients, MR imaging of the lung was successful. All 15 MR studies were compromised by artifacts; however, the severity of these artifacts was classified as low or moderate in 8/15, respectively, 7/15 cases. A total of 143/285 lung segments showed diffuse lung disease in helical CT. With MRI, 133 of these 143 segments (93%) were judged to be diseased. The ten segments that received false negative MR diagnoses displayed non-acute pulmonary lesions with inherently low proton density (scars, granulomas). MRI at 3.0 T can detect diffuse pulmonary disease with a high sensitivity. Based on this experience, further pulmonary studies with high-field systems appear justified and promising.

Radiation-induced changes occur at MR imaging during or up to 3 months after radiation therapy but are much less severe than reported. Detection and characterization of lesions were feasible with comparable diagnostic accuracies in irradiated and nonirradiated breasts.