RESULTS OF CONTRAST-MEDIUM SUPPORTED 3D M R-ANGIOGRAPHY IN RESPIRATORY ARREST AFTER OPTIMIZATION OF CONTRAST-MEDIUM BOLUS

Purpose: Reduction of the contrast material volume by optimised bolus administration during a breath-hold 3D MR angiography and its clinical value. Materials and methods: Breath-hold ultrafast 3D gadolinium-enh anced MR angiography (T-R 5 ms, T-E 2 ms, FA 20 degrees) of the thorac ic and abdominal aorta was performed in 50 patients and correlated wit h an i.a. DSA. 25 patients (group I)were examined with a contrast mate rial volume of 40 mi Cd-DTPA and three successive acquisitions at fixe d intervals (25, 53 and 81 s) after start of the contrast material inj ection. Another group of 25 patients (group 2) received only 20 mi Gd- DTPA and the start of the MR acquisition was determined individually b y prior evaluation of the contrast material transit times after inject ion of a test bolus. The signal-to-noise (S/N) and contrast-to-noise ( GIN) ratios were compared and a subjective image quality rating (0-3) by three reviewers was achieved in both groups. Results: A total of 37 vascular pathologies were correctly detected by MR angiography compar ed to i.a. DSA. The grading of stenoses was overestimated in some case s. The S/N and C/N were higher in group 2 (63.2 and 50.1) than in grou p 1 (58.0 and 38.9). The subjective ratings also showed better results in group 2 (2.76) than in group 1 (2.20). Conclusion: The ultrafast g adolinium-enhanced 3D MR angiography allowed a reliable visualisation of the thoracic and abdominal aorta and its branches in a single breat h-hold. An optimised examination with a reduced contrast material volu me can be achieved by an individual adaptation of the MR acquisition t o contrast material administration after measurement of the contrast m aterial transit times.