However, MRA and US duplex Doppler are typically preferred because they do not require ionizing radiation. MRA Lower Extremity MR angiography (MRA) can be used to evaluate vascular abnormalities and the dynamic changes in the popliteal artery during plantar flexion [16]. MRA is typically performed as a confirmatory test after US duplex Doppler. However, many patients are unable to maintain steady forced plantar flexion throughout the duration of lengthy MR sequences, resulting in excessive motion and degradation of image quality [7,8,15]. Despite this, a recent Nonatherosclerotic Peripheral Arterial Disease study demonstrated superiority of MRA over digital subtraction angiography (DSA) in confirming PAES [6]. MRA can be particularly helpful in defining abnormal musculotendinous structures. Furthermore, the T1- weighted and T2-weighted sequences done as part of the MRA study are currently the gold standard for defining the complete anatomy of the popliteal fossa and are therefore most appropriate for determining the anatomic abnormality in suspected PAES [7,15]. MRA without intravenous (IV) contrast is typically not used because the long acquisition times required cause challenges for their performance during stress maneuvers. However, the anatomic imaging used to determine the etiology of PAES can be done without IV contrast. Arteriography Lower Extremity Selective arteriography is regarded as the gold standard in identifying dynamic arterial deviation and/or occlusion during plantar flexion in addition to identifying vascular occlusion/stenosis, aneurysm, and thrombosis. [5,7,15]. In addition to being an invasive modality, arteriography is limited by its inability to depict extravascular anatomy. One study comparing the use of DSA and MRI in the evaluation of PAES found DSA to be nonspecific and unable to determine the etiology of patient symptoms [6], thereby obviating the need for cross-sectional imaging.
Nonatherosclerotic Peripheral Arterial Disease. However, MRA and US duplex Doppler are typically preferred because they do not require ionizing radiation. MRA Lower Extremity MR angiography (MRA) can be used to evaluate vascular abnormalities and the dynamic changes in the popliteal artery during plantar flexion [16]. MRA is typically performed as a confirmatory test after US duplex Doppler. However, many patients are unable to maintain steady forced plantar flexion throughout the duration of lengthy MR sequences, resulting in excessive motion and degradation of image quality [7,8,15]. Despite this, a recent Nonatherosclerotic Peripheral Arterial Disease study demonstrated superiority of MRA over digital subtraction angiography (DSA) in confirming PAES [6]. MRA can be particularly helpful in defining abnormal musculotendinous structures. Furthermore, the T1- weighted and T2-weighted sequences done as part of the MRA study are currently the gold standard for defining the complete anatomy of the popliteal fossa and are therefore most appropriate for determining the anatomic abnormality in suspected PAES [7,15]. MRA without intravenous (IV) contrast is typically not used because the long acquisition times required cause challenges for their performance during stress maneuvers. However, the anatomic imaging used to determine the etiology of PAES can be done without IV contrast. Arteriography Lower Extremity Selective arteriography is regarded as the gold standard in identifying dynamic arterial deviation and/or occlusion during plantar flexion in addition to identifying vascular occlusion/stenosis, aneurysm, and thrombosis. [5,7,15]. In addition to being an invasive modality, arteriography is limited by its inability to depict extravascular anatomy. One study comparing the use of DSA and MRI in the evaluation of PAES found DSA to be nonspecific and unable to determine the etiology of patient symptoms [6], thereby obviating the need for cross-sectional imaging.