Dynamic MRI contrast enhancement of renal cortex: a functional assessment of renovascular disease in patients with renal artery stenosis.
OBJECTIVE
To evaluate differences in the magnitude and time course of renal cortical contrast uptake in patients with minimal, moderate, and severe renal artery stenosis (RAS) using contrast-enhanced magnetic resonance renography (CE-MRR).


METHODS
CE-MRR was performed on 56 patients with renovascular disease using a three-dimensional volume interpolated breath-hold examination (VIBE) perfusion sequence. After administration of 2 mL of contrast, nine sequential axial VIBE datasets were acquired: at baseline, 7, 14, 21, 45, 60, 120, 180, and 240 seconds. Aortic peak signal enhancement and cortical peak signal enhancement through the mid portion of each kidney was recorded, along with the time delay between each peak. Each renal artery was subsequently examined using three-dimensional contrast-enhanced MR angiography, and graded as being minimally (0%-30%), moderately (31%-70%), or severely (71%-100%) stenotic.


RESULTS
When the data were subdivided by RAS category, the cortical to aortic peak enhancement ratio (CAPR) reduced with increasing RAS. Further, the cortical to aortic time delay (CATD) increased with increasing RAS. These measurements were statistically significant between patients with minimal and moderate RAS compared to severe RAS CONCLUSION: CE-MRR can assist in the differentiation of patients with minimal or moderate RAS from those with severe RAS.
D000368:Aged; D003287:Contrast Media; D005260:Female; D005682:Gadolinium; D006571:Heterocyclic Compounds; D006801:Humans; D006978:Hypertension, Renovascular / Q000473:pathology*; D021621:Imaging, Three-Dimensional; D007672:Kidney Cortex / Q000473:pathology*; D018810:Magnetic Resonance Angiography; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009942:Organometallic Compounds; D012078:Renal Artery Obstruction / Q000150:complications / Q000473:pathology*
D003287:Contrast Media; D006571:Heterocyclic Compounds; D009942:Organometallic Compounds; C062402:gadoteridol; D005682:Gadolinium