Noncontrast MR angiography creates equivalent image quality to contrast

Noncontrast MR angiography provides an alternative to the more common contrast-enhanced MRA administered with a gadubutrol-based agent, according to a report presented at the RSNA meeting Tuesday morning.

Dr. Christopher Francois, an assistant professor of radiology at the University of Wisconsin, and colleagues imaged 12 healthy volunteers and 51 patients with a 3D phase-contrast sequence and a novel respiratory gated phase-contrast vastly undersampled isotropic projection reconstruction (PC VIPR) sequence.

The researchers also acquired contrast-enhanced MRA exams and 2D phase-contrast data for several of the patients.

Francois and colleagues evaluated the images based on quality and visibility of vessels. Two blinded radiologists compared vessel visibility acquired with CE-MRA and PC VIPR independently and in random order.

The blinded radiologists reported equivalent overall image quality for both protocols. Poor breath-holds compromised quality for some CE-MRA scans, while PC VIPR had reduced image quality in highly obese patients.

Because CE-MRA scans and PC VIPR showed equivalent overall image quality, Francois said PC VIPR is a good alternative to CE-MRA, especially for patients who are at risk for nephrogenic systemic fibrosis.

PC VIPR has become the standard protocol at the University of Wisconsin, he said.

Future analysis will investigate the correlation of transstenotic pressure gradients obtained noninvasively with PC VIPR and invasively under x-ray fluoroscopy, according to Francois.