[Clinical value of new rapid nuclear magnetic resonance tomography in preoperative assessment of hypernephroma. A prospective comparative study of CT and MR].

The new technique of rapid magnetic resonance imaging (MRI) with a paramagnetic contrast agent provides excellent imaging of the kidneys and their lesions. MR imaging of this anatomical region at short breath holding intervals matches the well-known quality of computed tomography (CT) for the first time. MR and CT studies were performed on 36 patients with proven renal cell carcinoma. Different investigators evaluated the staging of the tumor by means of both techniques in a prospective study. In all patients a radical nephrectomy was performed. Surgical and pathological findings were compared. Though little difference was found in diagnostic value between the two systems, MRI results concerning the T-stage were better. Venous invasion was clearly shown by MRI without the use of contrast medium. Furthermore, sagittal and transaxial images provided a more direct assessment of the extent of the tumor and its demarcation to healthy parenchyma. Thus, MRI is helpful in planning of the surgical approach when organ-sparing excision of renal tumors is to be performed.