![]() 2,5 Ankle-Brachial Index (ABI)ĪBI is the easiest and most widely used measurement of noninvasive arterial testing. 3 Ultrasound has the advantage of being inexpensive, widely available, and does not use contrast media or ionizing radiation however, it may be limited in individuals with a large body habitus, lymphedema, lower extremity wounds, and those with extensive arteriosclerotic calcifications. 4 Additionally, ultrasound testing with color and pulsed wave Doppler has a high sensitivity (88%) and specificity (97%) in identifying stenoses of greater than 50% in the lower extremity. 3 Duplex ultrasound images the entire arterial tree of the lower extremity, distinguishing between occluded, stenotic, non-stenotic, and aneurysmal segments. This includes 2-dimensional structure and motion, Doppler spectrum analysis, and color flow velocity mapping.Ĭharacteristic duplex ultrasound features of stenosis include elevated velocities, color disturbance, spectral broadening, and post-stenotic waveforms. 3 Duplex scanning refers to an ultrasound scanning procedure recording both gray scale and Doppler information. According to Gerhard-Herman et al, this includes both segmental pressures and PVR testing. Physiologic testing or pulse-volume recording (PVR), which will be discussed in a later section of this review, evaluates the physiology of blood flow by evaluating flow pressures and waveforms. UltrasoundĪ standard vascular testing workup often includes both duplex ultrasound and physiologic evaluation. This article will review general principles, indications, interpretations, and limitations of several types of noninvasive vascular testing for peripheral arterial disease in the lower extremity. Early intervention with lipid-lowering therapy and antiplatelet drugs may delay disease progression and prevent premature death from cardiovascular causes. Because even asymptomatic individuals with PAD have an increased relative risk of death, screening of the at-risk population should be considered to identify the disease and begin treatment (see Figure 1). An understanding of the risk factors, diagnostic techniques and treatment options is essential for proper screening and care of affected individuals. 1 PAD is a common finding among patients over age 50, yet it is frequently underdiagnosed. ![]() Choosing the right diagnostic test is key.īy Brittany Mammano, DPM, PGY-1, and Saba Sadra, DPM, MScĮight million men and women in the United States have lower extremity peripheral arterial disease (PAD). Peripheral arterial disease may be a common finding among those over 50, but it remains underdiagnosed. Copyright © 2014 by the authors permission for reuse provided by the lead author. ![]() A practical approach to interpreting lower extremity noninvasive physiologic studies. Reprinted from McCann TE, Scoutt LM, Gunabushanam G. ABI, ankle brachial index CTA, computed tomography angiography MRA, magnetic resonance angiography PAD, peripheral arterial disease PVR, pulse-volume recording TBI, toe brachial index US, ultrasound. Please note that because of variations in physician preferences, it is common to perform rest ABI,TBI, segmental pressure measurements, and PVR in all patients with suspected PAD. Algorithm for the noninvasive vascular laboratory workup of patients with suspected PAD.
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