Designe of specific scanning scheme for 3D-CE-MRA by applying iPass

Objective: To investigate the clinical value of iPass in three dimensional contrast enhanced MR angiography (3D-CE-MRA). Methods: iPass were performed in 32 cases, including cervical vessel (4 cases), pulmonary vessel (7 cases), abdominal vessel (18 cases), and femoral vessel (3 cases). iPass bolus tracking was run before 3D-CE-MRA. The tracking sequence was operated repeatedly with real time display of image. The peak of bolus arrival time (Tp), identified with signal of target vessel increased 30% over baseline, was automatically loaded in the timing page of 3D-CE-MRA, and the time of scan delay (Td) was computed by the system with Tp. The acquired images were subtracted and reconstructed by MIP. The quality of MIP image was evaluated. Results: The iPass bolus tracking sequence and 3D-CE-MRA were completed successfully in 29 cases. The bolus tracking couldn't detect the bolus arrival time in 3 cases, but they were completed through changing ROI and bolus tracking repeatedly. The average score of 3D-CE-MRAMIP image was 3.81 ± 0.59. Conclusion: iPass can provide the exact Tp and automatically control Td of 3D-CE-MRA. iPass is a useful procedure to improve the image quality and provide the specific scanning scheme for 3D-CE-MRA. (authors)