However, hardware advances and faster, novel sequences such as quiescent interval slice- selective MRA and flow-sensitive dephasing have demonstrated comparable diagnostic accuracies to contrast- enhanced MRA in the evaluation of PAD in multiple prospective studies and trials [41-43]. The imaging-related disadvantages of MRA relative to CTA include lower signal-to-noise ratio, limited spatial resolution, longer acquisition times, and a greater potential for artifact-related image degradation, namely, from motion and susceptibility from metal stents and orthopedic hardware; techniques have been developed to address some of these issues [37-40]. MRA of the abdomen and pelvis can be obtained in addition to bilateral lower extremity runoff when aortoiliac disease is a concern or if the aorta and iliac arteries have not already been imaged and to assess for vascular suitability for endovascular intervention. MRA Lower Extremity Without and With IV Contrast The widespread adoption of 3T magnets has allowed for higher spatial resolution and signal-to-noise ratio acquisitions. In multiple meta-analyses and prospective studies, contrast-enhanced MRA for the detection of hemodynamically significant arterial stenosis has yielded a sensitivity and specificity up to 97% and 96%, respectively, when compared to DSA [31-34]. Compared to CTA, MRA does not suffer from artifact related to calcium within small vessels. In addition, time- resolved sequences allow for dynamic visualization and separation of arterial and venous flow, allowing for increased diagnostic accuracy. In a study comparing to DSA, contrast-enhanced, time-resolved MRA at 3T with calf compression to prevent venous contamination demonstrated superior visualization of below-the-knee arterial vasculature than DSA [35].
Sudden Onset of Cold Painful Leg. However, hardware advances and faster, novel sequences such as quiescent interval slice- selective MRA and flow-sensitive dephasing have demonstrated comparable diagnostic accuracies to contrast- enhanced MRA in the evaluation of PAD in multiple prospective studies and trials [41-43]. The imaging-related disadvantages of MRA relative to CTA include lower signal-to-noise ratio, limited spatial resolution, longer acquisition times, and a greater potential for artifact-related image degradation, namely, from motion and susceptibility from metal stents and orthopedic hardware; techniques have been developed to address some of these issues [37-40]. MRA of the abdomen and pelvis can be obtained in addition to bilateral lower extremity runoff when aortoiliac disease is a concern or if the aorta and iliac arteries have not already been imaged and to assess for vascular suitability for endovascular intervention. MRA Lower Extremity Without and With IV Contrast The widespread adoption of 3T magnets has allowed for higher spatial resolution and signal-to-noise ratio acquisitions. In multiple meta-analyses and prospective studies, contrast-enhanced MRA for the detection of hemodynamically significant arterial stenosis has yielded a sensitivity and specificity up to 97% and 96%, respectively, when compared to DSA [31-34]. Compared to CTA, MRA does not suffer from artifact related to calcium within small vessels. In addition, time- resolved sequences allow for dynamic visualization and separation of arterial and venous flow, allowing for increased diagnostic accuracy. In a study comparing to DSA, contrast-enhanced, time-resolved MRA at 3T with calf compression to prevent venous contamination demonstrated superior visualization of below-the-knee arterial vasculature than DSA [35].