Non-Enhanced MRI Planning for Endovascular Repair of Abdominal Aortic Aneurysms: Comparison With Contrast-Enhanced CT Angiography - Journal of Vascular Surgery

Single-center review between September 2013 and April 2015. There were 30 patients who underwent preoperative computed tomograqphy angiography (CTA) and noncontrast enhanced magnetic resonance imaging (NC-MRI) at a maximum interval of 60 days prior to endovascular aneurysm repair (EVAR). Two expert readers (vascular radiologist and vascular surgeon) reviewed CTA images and chose the proper endograft for each patient. A vascular radiologist and a resident radiologist reviewed CTA and NC-MRI examinations in a double-blind fashion. MRI sensitivity and specificity compared with CTA were 94% and 100%, respectively. CTA and NC-MRI angiographic measurements showed strong correlation, except for external iliac artery diameters. The choice of stent size was always the same between the two observers. Although CTA remains the gold standard, NC-MRI is a good alternative for EVAR planning such as for patients with renal impairment. The paper suggests that NC-MRI is a suitable alternative for CTA when planning EVAR. This imaging alternative most readily applies to patients with chronic renal failure where contrast would be contraindicated. Although gadolinium-enhanced MRA has been (rarely) associated with nephrogenic systemic fibrosis in patients with renal failure, omission of contrast when performing MRI, as in this report, would avoid this complication. The biggest concern for the vascular surgeon who is not experienced interpreting MRIs is relying on a radiologist to provide accurate measurements for EVAR planning based on NC-MRI. Nonetheless, NC-MRI may prove to be a valuable alternative when planning EVAR in patients with renal impairment by avoiding the use of contrast with CTA. However, we have successfully used noncontrast-enhanced CT scans to plan EVAR in patients with renal insufficiency. My question is which study is more accurate and reliable in patients requiring complicated endovascular repairs who have underlying renal insufficiency: CT scan without contrast or MRI without contrast?