Non-contrast-enhanced Magnetic Resonance Angiography In The Lower Extremities:A Study Of Improved Motion Sensitized Driven Equilibrium Prepared Balanced Steady-state Free Precession In The Patients With Diabetes

Purpose:To evaluate the diagnostic value of the non-contrast-enhanced magnetic resonance angiography(NCE-MRA)using improved motion sensitized driven equilibrium(iMSDE)prepared balanced steady-state free precession(bSSFP)sequence in the lower extremities in the patients with diabetes.Materials&Methods:This prospective study included a total of 35 patients with type II diabetes and 27 health controls,the diabetic patients who underwent CE-MRA on the 1.5T magnetic resonance scanner after the NCE-MRA,and the health controls only underwent NCE-MRA.The obtained maximum intensity projection(MIP)images were independently rated by two radiologist with a four score table and using CE-MRA as a reference standard to evaluate the diagnostic accuracy of NCE-MRA for the narrowed arteries(?50%).Signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)was measured for each diagnostic artery illustrated by the NCE-MRA and CE-MRA techniques.?2(Fisher exact probability method)test was used to calculate the percentages of diagnostic arteries for both the NCE-MRA and CE-MRA.The SNR and CNR between NCE-MRA and CE-MRA were compared by paired-t test.Results:The mean scan time of every segment(pelvic,thigh and calves)for NCE-MRA is from 240sec to 360sec.The percentage of diagnostic arteries in health controls is 92%(446/486).With NCE-MRA Compared to the CE-MRA,the percentage of diagnostic arteries with NCE-MRA in the pelvis segment(include common iliac artery,internal iliac artery and iliac artery)is descended(NCE-MRA:100/210,58%;CE-MRA:187/210,89%).The percentage of diagnostic arteries with NCE-MRA in the thigh and calves segment(include deep femoral artery and superficial femoral artery,popliteal artery,anterior tibial artery,posterior tibial artery and peroneal artery)is Increased or consistently(NCE-MRA:408/418,97%;CE-MRA:380/418,91%).There are no significant difference in SNR between NCE-MRA and CE-MRA(p=0.061).The CNR of NCE-MRA was lower than CE-MRA(p<0,001).The sensitivity,specificity,positive predictive value,negative predictive value,and accuracy of two readers in NCE-MRA were 95%/87%,96%/95%,57%/72%,99%/99%,and 96%/95%(k=0.76),respectively.Conclusion:The NCE-MRA using iMSDE prepared bSSFP sequence is capable of depicting vascular lesions for the lower extremities in diabetic patients with the advantages of contrast agent free,short scan times and good diagnostic value in the thigh and calves.