Arteriography Lower Extremity Because of its high inherent spatial resolution, selective arteriography with DSA is considered the gold standard in the diagnosis of FMD [25,26,36,38-40], with many authors claiming that CTA and MRA may lack the spatial resolution necessary to detect small-artery pathology [36]. Arteriography is susceptible to standing waves. Therefore, caution must be exercised to accurately distinguish standing waves from true arterial beading characteristic of FMD [15]. This modality may simultaneously be therapeutic in FMD, as angioplasty is currently the preferred treatment of choice [25,38,39]. Selective arteriography is considered the reference standard in the diagnosis of SAM while also having therapeutic potential [28]. US Duplex Doppler Lower Extremity A recent study found US duplex Doppler to be helpful in diagnosing cystic adventitial disease, where numerous anechoic cysts are seen scattered throughout the adventitia at a site of vessel stenosis [31]. While much has been published about the use of US duplex Doppler in renal artery FMD, no literature is currently present to support its use in the diagnosis of FMD affecting the lower-extremity arteries. US Intravascular Lower Extremity IVUS has been reported to be useful in diagnosing cystic adventitial disease [31]. In FMD, other authors have concluded that IVUS is likely more accurate than other modalities in characterizing the hemodynamic severity of encountered stenosis [39,41]. Variant 6: Lower-extremity vascular trauma. Initial imaging. CTA Lower Extremity CTA is considered especially important in the setting of trauma to the lower extremities. Several studies recognize its use as a first-line investigation in all patients with suspected vascular injury [42], demonstrating a sensitivity of 95% to 100% and a specificity of 87% to 100% [34,43]. Sensitivity for vascular injury in equivocal cases can be increased by using reconstructed images.
Nonatherosclerotic Peripheral Arterial Disease. Arteriography Lower Extremity Because of its high inherent spatial resolution, selective arteriography with DSA is considered the gold standard in the diagnosis of FMD [25,26,36,38-40], with many authors claiming that CTA and MRA may lack the spatial resolution necessary to detect small-artery pathology [36]. Arteriography is susceptible to standing waves. Therefore, caution must be exercised to accurately distinguish standing waves from true arterial beading characteristic of FMD [15]. This modality may simultaneously be therapeutic in FMD, as angioplasty is currently the preferred treatment of choice [25,38,39]. Selective arteriography is considered the reference standard in the diagnosis of SAM while also having therapeutic potential [28]. US Duplex Doppler Lower Extremity A recent study found US duplex Doppler to be helpful in diagnosing cystic adventitial disease, where numerous anechoic cysts are seen scattered throughout the adventitia at a site of vessel stenosis [31]. While much has been published about the use of US duplex Doppler in renal artery FMD, no literature is currently present to support its use in the diagnosis of FMD affecting the lower-extremity arteries. US Intravascular Lower Extremity IVUS has been reported to be useful in diagnosing cystic adventitial disease [31]. In FMD, other authors have concluded that IVUS is likely more accurate than other modalities in characterizing the hemodynamic severity of encountered stenosis [39,41]. Variant 6: Lower-extremity vascular trauma. Initial imaging. CTA Lower Extremity CTA is considered especially important in the setting of trauma to the lower extremities. Several studies recognize its use as a first-line investigation in all patients with suspected vascular injury [42], demonstrating a sensitivity of 95% to 100% and a specificity of 87% to 100% [34,43]. Sensitivity for vascular injury in equivocal cases can be increased by using reconstructed images.