Use of Parallel Imaging in Peripheral Contrast-enhanced Magnetic Resonance Angiography: Retrospective Study

Objective: To evaluate the application of a parallel imaging technique — generalised autocalibrating partially parallel acquisition — in peripheral contrast-enhanced magnetic resonance angiography. Patients and Methods: This was a retrospective review of 17 consecutive patients with peripheral vascular disease who underwent lower-extremity 3-dimensional contrast-enhanced magnetic resonance angiography from July 2003 to March 2005. Generalised autocalibrating partially parallel acquisition, with an acceleration factor of 2, was used in all 3 stations of a single-injection moving-table protocol. The image qualities, spatial, and temporal resolutions were evaluated. Results: In all patients, the arterial segments under evaluation attained diagnostic quality. The degree of venous contamination was acceptable without obscuring the arterial pathology. There were significant improvements in spatial resolution (68.6% in the pelvic station, 40.0% in the thigh station, and 20.0% in the calf station), so that submillimetre near-isotropic resolution (1.0 x 0.8 x 1.0 mm) could be achieved in below-knee vessels, therapy providing excellent vascular detail. The overall acquisition time of magnetic resonance angiography data was reduced by 9.7% (22.0% reduction in data-acquisition time for the calf station). The overall examination time was less than 45 minutes (including patient transport and postprocessing image reconstruction). None of the patients had an adverse reaction to the contrast agent or contrast administration. There was no technical failure reported. Conclusions: Parallel imaging with generalised autocalibrating partially parallel acquisition improves spatial and temporal resolution in peripheral contrast-enhanced magnetic resonance angiography. It is a reliable technique for optimising peripheral contrast-enhanced magnetic resonance angiography. Diagnostic high-quality images with an acceptable degree of venous contamination can also be achieved.