New renal CTA protocol results in improved findings with less contrast medium

Renal computed tomography angiography (CTA) is an effective resource for radiologists with numerous benefits, but it requires the application of contrast medium that could potentially cause issues in patients with renal impairment.

According to a new study published in Academic Radiology, utilizing an optimized renal multiphase computed tomography angiography (MP-CTA) protocol results in a significant reduction in contrast medium while also providing higher arterial attenuation.

The authors performed MP-CTA using 30 mL of contrast medium on 30 patients, comparing vessel attenuation, image noise and contrast-to-noise ratio to CTA using 80 mL of contrast medium. All 30 acquisitions were successful, and the MP-CTA protocol delivered high attenuation, “adequate” image noise and a “good” contrast-to-noise ratio. In addition, arterial enhancement was “significantly higher” compared to renal CTA.

“The proposed MP-CTA yielded a significantly higher enhancement of arterial vessels than the standard CTA protocol and allowed for a comprehensive morphologic evaluation of the kidneys,” wrote Andreas Helck, MD, of Ludwig-Maximilians-University Hospital in Munich, Germany, and colleagues. “Furthermore, dynamic information was provided and could be used for clarification of vascular lesions, as well as for calculation of distinct perfusion parameters.”

Helck et al. noted that the increase of dose exposure is a significant drawback of multiphase CT protocols such as the one they implemented in this study. They used a low-tube voltage adjustment to combat this issue, though the radiation exposure was still higher than traditional renal CTA. The mean effective radiation dose for MP-CTA was found to be 9 mSv.