In combination with spectral Doppler, inflow disease can often be excluded and can guide the interventional approach (ie, retrograde contralateral versus antegrade ipsilateral access). Duplex is valuable in the determination of flow within and beyond stented and stent-grafted segments, and is slightly less limited than CTA and MRA, particularly in smaller-caliber stents [22]. The identification and treatment of symptomatic restenosis associated with a previously treated segment has been shown to provide improved long-term outcomes and patency in both endovascular and surgical patients [79]. In many cases, patients can proceed directly to intervention with Duplex arterial mapping alone [16,17]. In the setting of bypass, Duplex can determine whether the graft is patent, threatened, or occluded, and often can identify specific segments of disease to guide either endovascular repair or surgical revision. Although nonenhanced MRA can provide imaging quality and diagnostic confidence levels similar to that from CE-MRA, protocols and image quality vary significantly between institutions. Additionally, the lack of time- resolved imaging limits evaluation in the infrageniculate segment. Its use is generally reserved for patients who require evaluation of suspected aortoiliac and femoropopliteal lesions in the setting of renal insufficiency. The use of this modality is likely to evolve over the next decade given the vast amount of research in this area over the past few years. CTA In the era of modern CTA, vascular imaging quality is similar to that of DSA, albeit with a modest limitation in the infrageniculate distribution due to contrast-timing issues and the frequency of tibial calcification. Through the acquisition of isotropic voxels on new scanners, images can be reconstructed in any plane, including curved planar reformats along the lumen of the vessel [80].
Lower Extremity Arterial Revascularization Post Therapy Imaging. In combination with spectral Doppler, inflow disease can often be excluded and can guide the interventional approach (ie, retrograde contralateral versus antegrade ipsilateral access). Duplex is valuable in the determination of flow within and beyond stented and stent-grafted segments, and is slightly less limited than CTA and MRA, particularly in smaller-caliber stents [22]. The identification and treatment of symptomatic restenosis associated with a previously treated segment has been shown to provide improved long-term outcomes and patency in both endovascular and surgical patients [79]. In many cases, patients can proceed directly to intervention with Duplex arterial mapping alone [16,17]. In the setting of bypass, Duplex can determine whether the graft is patent, threatened, or occluded, and often can identify specific segments of disease to guide either endovascular repair or surgical revision. Although nonenhanced MRA can provide imaging quality and diagnostic confidence levels similar to that from CE-MRA, protocols and image quality vary significantly between institutions. Additionally, the lack of time- resolved imaging limits evaluation in the infrageniculate segment. Its use is generally reserved for patients who require evaluation of suspected aortoiliac and femoropopliteal lesions in the setting of renal insufficiency. The use of this modality is likely to evolve over the next decade given the vast amount of research in this area over the past few years. CTA In the era of modern CTA, vascular imaging quality is similar to that of DSA, albeit with a modest limitation in the infrageniculate distribution due to contrast-timing issues and the frequency of tibial calcification. Through the acquisition of isotropic voxels on new scanners, images can be reconstructed in any plane, including curved planar reformats along the lumen of the vessel [80].