[Diagnosis of the aortocoronary bypass--a comparison of MRT and CT].

Complaints of angina pectoris after aortocoronary bypass surgery can be due to the obturation of one or more bypasses. The aim of our study was the evaluation of magnetic resonance tomography for the investigation of bypass patency in comparison with computed tomography. We investigated 18 patients. 33 of 35 bypasses were safely detectable with spin-echo techniques and 32 with fast-scan-techniques and presentation in cine-mode. 25 of 33 bypasses were identified as open with the SE-technique, 27 of 32 with the "fast" technique. No safe decision was possible for 4 bypasses with SE-technique and for 1 bypass with the "fast" technique. The results are in good agreement with the reference investigation by CT. For the investigation of bypass patency with MRT neither x-rays nor contrast media are necessary. It is therefore recommended for patients with allergy to contrast media and cases with high radiation risk.