This chapter reviews the current status of duplex scanning for the initial evaluation of lower extremity arterial disease. Although women had smaller arteries than men, peak systolic flow velocities did not differ significantly between men and women in this study. Spectral waveforms obtained from a normal proximal superficial femoral artery. In Bernstein EF, editor: Noninvasive diagnostic techniques in vascular disease, St. Louis, 1985, Mosby, pp 619631. National Library of Medicine 15.6 ). Subsequent advances in technology made it possible to obtain ultrasound images and blood flow information from the more deeply located vessels in the abdomen and lower extremities. Both ultrasound images and Doppler signals are best obtained in the longitudinal plane of the aorta, but transverse views are useful to define anatomic relationships, assess branch vessels, and determine the cross-sectional lumen (Figure 17-3). The flow pattern in the center stream of normal lower extremity arteries is relatively uniform, with the red blood cells all having nearly the same velocity. Note. Cassottana P, Badano L, Piazza R, Copello F. Jamialahmadi T, Reiner , Alidadi M, Almahmeed W, Kesharwani P, Al-Rasadi K, Eid AH, Rizzo M, Sahebkar A. J Clin Med. The velocity ratio (peak systolic velocity divided by the systolic velocity in the normal proximal segment) is elevated at 6.2. A stenosis of greater than 70% was diagnosed either if the peak systolic velocity was more than 160 cm/sec (sensitivity 77%, specificity 90%) of if there was an increase in peak systolic velocity of 100% with respect to the arterial segment above the stenosis (sensitivity 80%, specificity 93%). Locate the common femoral vessels in the groin in the transverse plane. As the popliteal artery is scanned in a longitudinal view, the first bifurcation encountered below the knee joint is usually the anterior tibial artery and the tibioperoneal trunk. Because local flow disturbances are usually apparent with color flow imaging (see Figure 17-1), pulsed Doppler flow samples may be obtained at more widely spaced intervals when color flow Doppler is used. Thus, color flow imaging reduces examination time and improves overall accuracy. In general, the highest-frequency transducer that provides adequate depth penetration should be used. The common femoral artery arises as a continuation of the external iliac artery after it passes under the inguinal ligament. Follow distally to the dorsalis pedis artery over the proximal foot. Elevated peak systolic velocity at the stenosis with pansystolic spectral broadening. However, the peak systolic velocities (PSVs) decreased steadily from the iliac to the popliteal arteries. The peak velocities. Means are indicated by transverse bars. Purpose: Any stenosis or occlusion lengths, including measurements from the groin crease, patella or malleolus. Magnetic resonance angiography (MRA) and computed tomographic angiography (CTA) can also provide an accurate anatomic assessment of lower extremity arterial disease without some of the risks associated with catheter arteriography. Measurements by duplex scanning in 55 healthy subjects. Measurement of volume flow in the human common femoral artery using a Pulsed Doppler spectral waveforms are best obtained in a long-axis view (longitudinal plane of the aorta), but transverse B-mode image views are useful to define anatomic relationships, to identify branch vessels, to measure arterial diameters, and to assess the cross-sectional features of the aorta ( Fig. The purpose of noninvasive testing for lower extremity arterial disease is to provide objective information that can be combined with the clinical history and physical examination to serve as the basis for decisions regarding further evaluation and treatment. The origin of the internal iliac artery is used as a landmark to separate the common iliac artery from the external iliac artery. The current version of these criteria is summarized in Table 15.2 and Fig. Similar to other arterial applications of duplex scanning, the lower extremity assessment relies on high quality B-mode imaging to identify the artery of interest and facilitate precise placement of the pulsed Doppler sample volume for spectral waveform analysis.9 Both color flow and power Doppler imaging provide important flow information to guide spectral Doppler interrogation. Before is facilitated by visualization of the adjacent paired veins (see Figure 17-2). The common femoral artery begins four centimeters proximal, or cephalad, to the inguinal ligament. The 2023 edition of ICD-10-CM I87.8 became effective on October 1, 2022. 2023 ICD-10-CM Diagnosis Code I87.8 - ICD10Data.com These vessels are best evaluated by identifying their origins from the distal popliteal artery and scanning distally or by finding the arteries at the ankle and working proximally. FAPs were measured at rest and during reactive hy- peremia, which was induced by the intraartcrial injec- SCAN PROTOCOL Role of Ultrasound To date, there have been many criteria proposed for grading the degree of arterial narrowing from the duplex scan. angle of the ultrasound beam than color Doppler, and it tends to produce a more arteriogram-like vessel image. This suggests: - SFA aneurysm - Mild SFA stenosis - SFA occlusion - >50% SFA stenosis - >80% SFA stenosis - >50% SFA stenosis The velocities measured in a reversed saphenous vein bypass graft are usually: NB: If the stenosis is short, there can be a return to triphasic flow dependant on the ingoing flow and quality of the vessels. Loss of the reverse flow component occurs in normal lower extremity arteries with the vasodilatation that accompanies exercise, reactive hyperemia, or limb warming. appendix: on CT <6 mm caliber. Occlusion of an arterial segment is documented when no Doppler flow signals can be detected in the lumen of a clearly imaged vessel. Our experience suggests fasting does not improve scan quality. Examination of the abdominal aorta and iliac arteries is facilitated by scanning the patient following an overnight fast to reduce interference by bowel gas. Experimental work has shown that the high-velocity jets and turbulence associated with arterial stenoses are damped out over a distance of only a few vessel diameters. The deep and superficial portions continue on down the leg. Double-check Duplex Scan Documentation - AAPC Knowledge Center Following the stenosis the turbulent flow may swirl in both directions. TABLE 17-1 Mean Arterial Diameters and Peak Systolic Flow Velocities*. A standard duplex ultrasound system with high-resolution B-mode imaging, pulsed Doppler spectral waveform analysis, and color flow Doppler imaging is adequate for scanning of the lower extremity arteries. For a complete lower extremity arterial evaluation, scanning begins with the upper portion of the abdominal aorta. The diameter of the CFA increases with age, initially during growth but also in adults. official website and that any information you provide is encrypted Per University of Washington duplex criteria: The velocity criteria used in bypass graft surveillance is similar to above, except that EDV is not used and mean graft velocity, which is just the average PSV of 3-4 PSV of non-stenotic segments of the graft, is used. Common femoral artery 114 cm/s Superficial femoral artery 91 cm/s Popliteal artery 69 cm/s Peripheral artery stenosis is considered significant when the diameter reduction is 50% or greater, which corresponds to 75% cross sectional area reduction. As discussed in Chapter 12 , the nonimaging or indirect physiologic tests for lower extremity arterial disease, such as measurement of ankle-brachial index, segmental limb pressures and pulse volume recordings, provide valuable physiologic information, but they give relatively little anatomic detail. The patient is initially positioned supine with the hips rotated externally. FAPs. Noninvasive Diagnosis of Arterial Disease | PDF | Medical Ultrasound To determine the relevance of dilatations of the common femoral artery (CFA), knowledge of the normal CFA diameter is essential. Some institutions fast their patients to aid visualisation of the aorta and iliac arteries. Spectral waveforms obtained just proximal to the origin of the celiac artery show a normal aortic flow pattern. Often, flow through the collateral vessels can be robust, resulting in normal pedal pulses despite occlusion of the superficial femoral artery. mined by visual interpretation of the Doppler velocity spectrum. The reverse flow component is a consequence of the relatively high peripheral vascular resistance in the normal lower extremity arterial circulation. . This site needs JavaScript to work properly. These vessels are best evaluated by identifying their origins from the distal popliteal artery and scanning distally or by finding the arteries at the ankle and working proximally. 15.3 ). 3. 5 Q . Front Sports Act Living. Lower Extremity Arterial Disease | Radiology Key Results: We enrolled 66 patients (mean age: 30.78.6 years). Using a curvilinear 3-5MHz transducer. There was a signi cant inversely proportio- For the evaluation of the abdominal aorta and lower extremity arteries, pulsed Doppler measurements should include the following standard locations: (1) the proximal, middle, and distal abdominal aorta; (2) the common iliac, proximal internal iliac, and external iliac arteries; (3) the common femoral and proximal deep femoral arteries; (4) the proximal, middle, and distal superficial femoral artery; (5) the popliteal artery; and (6) the tibial/peroneal arteries at their origins and at the level of the ankle. The waveforms show a triphasic velocity pattern and contain a narrow band of frequencies with a clear area under the systolic peak. Young Jin . The single arteries and paired veins are identified by their flow direction (color). This is necessary because the flow disturbances produced by arterial lesions are propagated along the vessel for a relatively short distance. 1998 Aug;28(2):284-9. doi: 10.1016/s0741-5214(98)70164-8. Skin perfusion pressure is used in patients with critical limb ischemia requiring surgical reconstruction or amputation. and transmitted securely. The initial application of duplex scanning concentrated on the clinically important problem of extracranial carotid artery disease. Open in viewer Conditions that produce an increased flow to the limb muscles, such as exercise, increased limb temperature, and/or arteriovenous fistula, do so in part by dilating the arterioles in the muscle bed allowing forward flow throughout diastole. The maximum and mean values of WSS, and the Tur values at early-systole, mid-systole, late-systole, and early diastole for total 156 normal peripheral arteries [common carotid arteries (CCA), subclavian arteries (SCA), and common femoral arteries (CFA)] were assessed using the V Flow technique.ResultsThe mean WSS values for CCA, SCA, and CFA . Three consecutive measurements were taken of each the following arterial segments: common femoral artery (CFA), superficial femoral artery (SFA), popliteal artery (PA), dorsalis pedis artery (DPA), and common plantar artery (CPA). This may require applying considerable pressure with the transducer to displace overlying bowel loops. Ultrasound Doppler estimates of femoral artery blood flow during Spectral waveforms taken from normal lower extremity arteries show the characteristic triphasic velocity pattern that is associated with peripheral arterial flow (Figure 17-7). Peri-aortic soft tissues are within normal limits." Comment: Both color Doppler and spectral Doppler are noted in addition to a statement on the flow pattern. Increased flow velocity. Rarely used and not specific to disease, with 50% false positive rate. 2022 Feb 24;4:799659. doi: 10.3389/fspor.2022.799659. Several large branches can often be seen originating from the distal superficial femoral and popliteal segments. When a hemodynamically significant stenosis is present within . FIGURE 17-4 Color flow image of a normal aortic bifurcation obtained from an oblique approach at the level of the umbilicus. FIGURE 17-6 Example of a vascular laboratory worksheet used for lower extremity arterial assessment. Severe limb ischaemia (SLI) and intermittent claudication (IC) are the main clinical presentations in LEAD [1]. reflected sound waves.1,3.4.6 The transmission of the inau dible sound beam is continuous at a specific frequency, usually 5 to 711z . Normal lower extremity arterial spectral waveforms demonstrate a triphasic flow pattern, and the PSV decreases steadily from the iliac arteries to the calf arteries. Although women tended to have higher time-averaged mean velocities in the CFA and SFA than men (t-test, p < 0.008), their arterial cross-sectional areas tended to be smaller (t-test, p < 0.004) and no statistically significant difference was found between men and women in volumetric flow at any site. An electric blanket placed over the patient prevents vasoconstriction caused by low room temperatures. They may also occur when an aneurysmal artery ruptures into an adjacent vein (as can happen with coronary artery aneurysms). External iliac artery | Radiology Reference Article - Radiopaedia 15.5 ). Heavily calcified vessels and large patient habitus reduce detail and may limit ability to obtain a good doppler trace accurately angle corrected. Pulsed Doppler spectral waveforms are also recorded from any areas in which increased velocities or other flow disturbances are noted with color Doppler imaging. The color flow image shows the common femoral artery bifurcation and the location of the pulsed Doppler sample volume. Although an angle of 60 degrees is usually obtainable, angles of less than 60 degrees can be used to provide clinically useful information. Narrowing of the CIV is apparent with mosaic color due to aliasing from the high velocity. 2023 Feb;22(1):189-205. doi: 10.1007/s10237-022-01641-x. When low-resistive waveforms are detected in the arteries distal to a high-grade stenosis, this pattern is usually . Careers. Interpretation of peripheral arterial and venous Doppler waveforms: A atlantodental distance. Bidirectional flow signals. Longitudinal B-mode image of the proximal abdominal aorta. The iliac arteries are then examined separately to the level of the groin with the transducer placed at the level of the iliac crest to evaluate the middle to distal common iliac and proximal external iliac arteries ( Fig. Noninvasive testing for lower extremity arterial disease provides objective information that can be combined with the clinical history and physical examination to serve as the basis for decisions regarding further evaluation and treatment. As with other applications of arterial duplex scanning, Doppler angle correction is required for accurate velocity measurements. This may be uncomfortable on the patient. Increased signal amplitude affecting slow flow velocities. Linear relationships between the reciprocal of PI and volume flow were found and expressed as linear blood flow equations. A left lateral decubitus position may also be advantageous for the abdominal portion of the examination. Federal government websites often end in .gov or .mil. These studies are usually guided by the indirect studies that identify a region of abnormality. Waveforms differ by the vascular bed (peripheral, cerebrovascular, and visceral circulations) and the presence of disease. CFA, common femoral artery; CW, continuous wave; PRA, profunda artery; PRF . In addition, catheter contrast arteriography provides anatomic rather than physiologic information and may be subject to variability at the time of interpretation. 1998 Nov;16(11):1593-602. doi: 10.1097/00004872-199816110-00005. The color change in the common iliac segment is related to different flow directions with respect to the transducer. The amplitude is decreased but not as much as obstructive waveforms. These are some common normal peak systolic velocities: Peripheral artery stenosis is considered significant when the diameter reduction is 50% or greater, which corresponds to 75% cross sectional area reduction. If possible, roll the patient onto their ipsilateral side with the contralateral leg forward over the top. FIGURE 17-8 Lower extremity artery spectral waveforms. Lengths of occluded arterial segments can be measured with a combination of B-mode, color flow, and power Doppler imaging by visualizing the point of occlusion proximally and the distal site where flow reconstitutes through collateral vessels. Locate the popliteal artery at the knee crease in transverse and follow proximally up between the hamstrings, and distally until you see the bifurcation (anterior tibial and tibio-peroneal trunk). Abnormal low-resistive waveform in the left common femoral artery, proximal to the arteriovenous graft (AVG). Duplex image of a severe superficial femoral artery stenosis. Low-frequency (2 MHz or 3 MHz) transducers are best for evaluating the aorta and iliac arteries, whereas a higher-frequency (5 MHz or 7.5 MHz) transducer is adequate in most patients for the infrainguinal vessels. The stenosis PSV to pre-stenotic PSV is 2.0 or greater. Dorsalis Pedis Artery: Anatomy, Function, and Significance Duplex velocity characteristics of aortoiliac stenoses 2022 May-Jun;19(3):14791641221094321. doi: 10.1177/14791641221094321. No flow is seen in the left CIV, whereas normal flow is observed in the right CIV (B). Duplex instruments are equipped with presets or combinations of ultrasound parameters for gray-scale and Doppler imaging that can be selected by the examiner for a particular application. Common femoral endarterectomy has been the preferred treatment . An official website of the United States government. These vessels are best evaluated by identifying their origins from the distal popliteal artery and scanning distally or by finding the arteries at the ankle and working proximally. These presets can be helpful, especially during the learning process, but these parameters may not be adequate for all patient examinations. An important difference between spectral waveform analysis and color flow imaging is that spectral waveforms display the entire frequency and amplitude content of the pulsed Doppler signal at a specific site, whereas the color flow image provides a single estimate of the Doppler shift frequency or flow velocity for each site within the B-mode image. FIGURE 17-5 Color flow image of a normal right common iliac artery bifurcation obtained at the level of the iliac crest. Normal Peak Systolic Flow Velocities and Mean Arterial Diameters. Catheter contrast arteriography has generally been regarded as the definitive examination for lower extremity arterial disease, but this approach is invasive, expensive, and poorly suited for screening or long-term follow-up testing. Running as a continuation of the anterior tibial artery, the blood vessel carries oxygenated blood to the dorsal surface (upper side) of the foot. A list of normal radiological reference values is as follows: adrenal gland: <1 cm thick, 4-6 cm length. The common femoral artery is a continuation of the external iliac artery.