Image analysis in time-resolved large field of view 3D MR-angiography at 3T.

PURPOSE: To qualitatively and quantitatively evaluate the image quality in accelerated time-resolved 3D contrast-enhanced MR angiography (tr-CE-MRA) at 3T.

MATERIALS AND METHODS: In all, 113 MRA were performed in 107 patients on a 3T MR system after written informed consent and approval by the ethics committee. Twenty consecutive thoracic (n=87) or craniocervical (n=26) 3D data volumes were acquired. The timeframes with maximum arterial and venous contrast were determined and a total of 663 arterial and venous segments were analyzed by two blinded observers. Diagnostic image quality was graded by applying a 0 (low) to 3 (excellent) scale. Additionally, local signal-to-noise (SNR) and contrast-to-noise ratios (relative CNR) were evaluated.

RESULTS: Tr-CE-MRA was successfully performed in all patients. Good to excellent image quality (2.42+/-0.31) was observed in all individuals with preserved discrimination of arteries (2.43+/-0.48) and veins (2.20+/-0.56). Minor image degradation due to artifacts (2.62+/-0.25) and constantly high vascular signal and contrast were detected. There was a significant superiority of coronal orientation during thoracic MRA (P<0.05). In 18 cases tr-CE-MRA provided additional information on vascular pathologies.

CONCLUSION: Large field of view tr-CE-MRA enables constantly high-quality thoracic and craniocervical angiographies. In addition, the dynamics of tr-CE-MRA can offer additional information on vascular pathologies.