Fast dynamic gadolinium-enhanced MR imaging of urinary bladder and prostate cancer

Among the noninvasive imaging modalities, contrast enhanced magnetic resona nce (MR) imaging is the most powerful tool with which to visualize vascular ity, Common pathology only shows microvessel density, whereas dynamic MR im aging is sensitive to the total endothelial surface area of perfused vessel s. Therefore, dynamic MR imaging may be of additional value in tumor stagin g and in evaluating therapies that affect the perfused microvessel density or surface area, such as chemo-, radiation, or anti-angiogenic therapy. In urinary bladder cancer, this technique results in improved local and nodal staging, in improved separation of transurethral granulation tissue and ede ma from malignant tumor, and in improved evaluation of the effect of chemot herapy. In prostate cancer, dynamic MR imaging may be of help in problemati c cases, This technique can assist in determining seminal vesicle infiltrat ion, in depicting of minimal capsular penetration, and in recognizing tumor s within the transitional zone, Also, based on very rapid enhancement, very poorly differentiated tumors can be recognized. Evaluation of the effects of therapy is another promising area, however a lot of research remain to b e done, This article reviews some basics of fast enhancement techniques, pr ovides practical information, and shows recent developments, in using these fast techniques for staging and grading of bladder and prostate cancer, an d for evaluating the effect of therapy. (C) 1999 Wiley-Liss, Inc.