DOI: 10.1148/rg.25si055511
RadioGraphics 2005;25:S133-S142
© RSNA, 2005
Diagnosing Traumatic Arterial Injury in the Extremities with CT Angiography: Pearls and Pitfalls1
Michelle M. Miller-Thomas, MD,
O. Clark West, MD and
Alan M. Cohen, MD
1 From the Department of Diagnostic and Interventional Imaging, University of Texas Medical School at Houston, 6431 Fannin St, Houston, TX 77030. Presented as an education exhibit at the 2004 RSNA Annual Meeting. Received February 17, 2005; revision requested March 22 and received April 5; accepted April 15. All authors have no financial relationships to disclose.
Address correspondence to M.M.M.T. (e-mail: Michelle.M.Miller-Thomas{at}uth.tmc.edu).
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Abstract
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Computed tomographic (CT) angiography is a reliable and convenient imaging modality for diagnosing arterial injuries after blunt and penetrating trauma to the extremities. It is a noninvasive modality that could replace conventional arteriography as the initial diagnostic study for arterial injuries after trauma to the extremities. The technique requires scanning with multidetector helical CT after rapid intravenous injection of iodinated contrast material. The CT angiographic signs of arterial injuries in the extremities are active extravasation of contrast material, pseudoaneurysm formation, abrupt narrowing of an artery, loss of opacification of a segment of artery, and arteriovenous fistula formation. Metallic streak artifact, motion artifact, and inadequate arterial opacification may render a CT angiogram nondiagnostic. Studies have shown the sensitivity of CT angiography to be 90%–95.1% and its specificity 98.7%–100% for detecting arterial injury to the extremities after trauma.
© RSNA, 2005
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LEARNING OBJECTIVES FOR TEST 4
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After reading this article and taking the test, the reader will be able to:
- Describe the technique for performing CT angiography of the extremities to detect traumatic arterial injury.
- Identify the five CT angiographic signs of arterial injury in the extremities.
- Discuss the pitfalls in CT angiography of the extremities in the setting of trauma.
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Introduction
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Arterial injury may occur after blunt or penetrating trauma to the extremities. Clinical outcome depends on rapid diagnosis and repair of the injury. Conventional arteriography is the current imaging method of choice for diagnosing traumatic arterial injuries to the extremities. Computed tomographic (CT) angiography is a noninvasive and rapid imaging technique that shows high sensitivity and specificity in the detection of arterial injuries in the extremities. We discuss the clinical signs of such injuries, techniques for CT angiography of the extremities, CT angiographic signs of arterial injury, and the three most common pitfalls in CT angiographic imaging of the extremities. Finally, we briefly summarize the scientific literature on CT angiography of the extremities for the diagnosis of arterial injuries.
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Background
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According to the surgical and trauma literature, prompt repair of arterial injuries to the extremities improves outcome in terms of limb function and mortality related to blood loss (1–4). Conventional arteriography was developed in the 1970s, allowing for accurate diagnosis of arterial injury with a less invasive procedure than open surgical exploration of the vessels. It has an associated morbidity of 1%–2%, but the benefits of its high diagnostic accuracy and of early percutaneous intervention for selected types of arterial injury outweigh the risks of a missed diagnosis of acute arterial injury in the extremities (2,3,5).
Three major disadvantages of conventional arteriography are the cost of the procedure; the delay that occurs before arteriography; and the need for a specialized team comprising a physician, angiography technologist, and nurse. A non-invasive, accurate, and easily accessible diagnostic imaging test acquired by a single trained technologist would reduce the time to diagnosis of traumatic arterial injury, facilitating rapid intervention (6,7). Use of duplex ultrasonography with Doppler evaluation for diagnosis in the emergency setting has been explored but has not become widely used because its sensitivity is lower than that of arteriography and because its performance is highly dependent on the skill of the operator (8–11). Magnetic resonance angiography is another possible modality for diagnosing arterial injury, but it has not come into widespread use because it is currently not practical to perform in the setting of trauma (7,12).
Multidetector helical computed tomographic (CT) scanners provide rapid acquisition of thin axial images, enabling CT angiography. Compared with conventional arteriography, CT angiography performs well for diagnosing occlusive disease in the lower extremities and for imaging other arteries of the body (13–19). CT technologists can be easily trained in CT angiographic techniques. Since 1999, CT angiography has shown excellent diagnostic performance for imaging traumatic arterial injuries in the extremities (20–22). It is an attractive initial diagnostic imaging technique in the trauma setting because of rapid access to multidetector CT in trauma departments.
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Clinical Signs
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Arterial injury may occur with either blunt or penetrating trauma. Blunt trauma injures vessels by crushing tissue, tearing tissue, dislocating joints, or breaking bones near arteries. Penetrating injuries, caused by a sharp object or disruption of tissue by a high-velocity penetrating missile, may result in laceration of an artery. Signs of arterial injury include loss of pulses in an extremity, expanding hematoma, thrill or bruit, active pulsatile bleeding, and neurologic deficit in the limb. Because there is a high correlation between these clinical findings and the presence of arterial injury, these "hard" signs warrant evaluation for arterial injury (1,3). "Soft" signs of arterial injury include a cool limb, change in color, nonexpanding hematoma, and nonpulsatile bleeding. The prevalence of arterial injury is lower when only soft clinical signs are present (23). Table 1 summarizes these clinical signs of arterial injury in the extremities. Serious arterial injury is less frequent in proximity injuries, that is, penetrating injuries in which the trajectory of the penetrating object through the tissue passes near arteries but in which there are no hard signs of arterial injury (5,24).
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Imaging
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Multiple parts of the body can be rapidly examined with multidetector CT during the same scanning session. CT angiography may be performed in a trauma victim after scanning of the head without contrast material and before scanning of the abdomen and pelvis with contrast material enhancement. Although we do not perform combined chest and extremity CT angiography with our equipment, CT scanners with 16 or more detector rows may be able to perform both studies with administration of one contrast medium bolus. CT angiography allows for rapid diagnosis of arterial injuries in the extremities while other injuries are being evaluated in patients who have suffered trauma. This multisystem assessment improves the efficiency of the radiologist and reduces the delay in diagnosis that occurs with conventional arteriography. Planning for repair of an arterial injury in a patient who requires emergency surgery for another life-threatening condition may be expedited when CT angiography is performed before surgery.
CT angiography is performed with multidetector helical CT scanners. In trauma cases, we perform CT angiography with a GE Lightspeed QXi, acquiring four rows of 1.25-mm sections at a pitch of 1.5 (GE Medical Systems, Milwaukee, Wis). These parameters allow for creation of diagnostic-quality reformatted images. An 18-gauge venous catheter is placed routinely at the level of the antecubital fossa and less commonly in the common femoral vein. We administer 150 mL of iohexol (Omnipaque, 300 mg of iodine per milliliter; Amersham, Ireland) intravenously with a power injector, at a rate of 4 mL/sec. Scanning is delayed for 25 seconds after the beginning of the injection for upper-extremity scanning or 50 seconds for lower-extremity scanning. Sometimes, an automated contrast monitoring protocol is used (SmartPrep, GE Medical Systems), with the region of interest placed over the common femoral artery or axillary artery to detect arterial opacification before scanning is initiated. In cases of upper-extremity trauma, intravenous contrast material should be injected in the contralateral arm to avoid streak artifact from a densely opacified vein adjacent to an injured upper-extremity artery. Ideally, the upper extremities should be raised above the head for scanning to limit the streak artifact from the body, but this position may not be possible with some injuries.
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Image Interpretation
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Both axial and reformatted CT angiograms should be reviewed. Between 150 and 300 axial images with two to 10 reformatted images are created for upper-extremity CT angiograms. Between 250 and 750 axial images with two to 10 reformatted images are created for lower-extremity CT angiograms. The interpreting radiologist at our institution creates either two-dimensional multiplanar reformatted images or maximum intensity projection images from the 1.25-mm reconstructed axial sections on a GE Advantage 4.2 workstation (GE Medical Systems). The radiologist should manipulate the image data to display the artery in a plane that optimizes visualization of the injury. An arterial injury may be more obvious when the reformatted images are reviewed than when the axial images are interpreted alone. We know of no published reports comparing three-dimensional maximum intensity projection reconstruction techniques with two-dimensional multiplanar reformatting techniques for viewing images, and radiology groups researching CT angiography for arterial injury in the extremities have different preferences regarding reformatting techniques (20–22).
CT angiographic signs of arterial injury include active extravasation of contrast material, pseudo-aneurysm formation, abrupt narrowing of an artery, loss of opacification of an arterial segment, and arteriovenous fistula formation. Examples of these signs are given in Figures 1–5. Intimal flap arterial injuries in the extremities are observed with conventional arteriography. We have not observed intimal flap injuries in our 3 years of experience with extremity CT angiography, perhaps because the resolution of CT angiography with a four-row multidetector CT scanner is less than that required to image an intimal flap in the extremities.
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Figure 1a. Active contrast material extravasation after penetrating upper-extremity injury. (a, b) Two sequential axial CT angiographic images (a obtained at a higher level than b) show active contrast material extravasation from the axillary artery (arrow). (c) Oblique coronal reformatted image also demonstrates active contrast material extravasation (arrow).
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Figure 1b. Active contrast material extravasation after penetrating upper-extremity injury. (a, b) Two sequential axial CT angiographic images (a obtained at a higher level than b) show active contrast material extravasation from the axillary artery (arrow). (c) Oblique coronal reformatted image also demonstrates active contrast material extravasation (arrow).
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Figure 1c. Active contrast material extravasation after penetrating upper-extremity injury. (a, b) Two sequential axial CT angiographic images (a obtained at a higher level than b) show active contrast material extravasation from the axillary artery (arrow). (c) Oblique coronal reformatted image also demonstrates active contrast material extravasation (arrow).
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Figure 2a. Pseudoaneurysm formation after penetrating lower-extremity injury. (a) Axial CT angiographic image obtained at the level of the popliteal fossa shows a pseudoaneurysm arising from the popliteal artery (arrow). A bullet fragment (B) is also present adjacent to the tibia, causing mild metallic streak artifact. (b) Sagittal reformatted image also demonstrates the popliteal artery pseudoaneurysm (arrow) with two metallic bullet fragments (B) proximal to the injury.
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Figure 2b. Pseudoaneurysm formation after penetrating lower-extremity injury. (a) Axial CT angiographic image obtained at the level of the popliteal fossa shows a pseudoaneurysm arising from the popliteal artery (arrow). A bullet fragment (B) is also present adjacent to the tibia, causing mild metallic streak artifact. (b) Sagittal reformatted image also demonstrates the popliteal artery pseudoaneurysm (arrow) with two metallic bullet fragments (B) proximal to the injury.
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Figure 3a. Abrupt narrowing of an artery after a dog bite to the upper extremity. (a) Axial CT angiographic image of the upper extremity shows that the brachial artery is near normal in caliber (arrow). (b) Axial image obtained a few sections distal to a shows narrowing of the brachial artery (arrow). (c) Next distal axial image shows loss of opacification of the brachial artery. (d) Coronal oblique reformatted image shows abrupt narrowing of the contrast material column in the brachial artery (arrow).
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Figure 3b. Abrupt narrowing of an artery after a dog bite to the upper extremity. (a) Axial CT angiographic image of the upper extremity shows that the brachial artery is near normal in caliber (arrow). (b) Axial image obtained a few sections distal to a shows narrowing of the brachial artery (arrow). (c) Next distal axial image shows loss of opacification of the brachial artery. (d) Coronal oblique reformatted image shows abrupt narrowing of the contrast material column in the brachial artery (arrow).
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Figure 3c. Abrupt narrowing of an artery after a dog bite to the upper extremity. (a) Axial CT angiographic image of the upper extremity shows that the brachial artery is near normal in caliber (arrow). (b) Axial image obtained a few sections distal to a shows narrowing of the brachial artery (arrow). (c) Next distal axial image shows loss of opacification of the brachial artery. (d) Coronal oblique reformatted image shows abrupt narrowing of the contrast material column in the brachial artery (arrow).
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Figure 3d. Abrupt narrowing of an artery after a dog bite to the upper extremity. (a) Axial CT angiographic image of the upper extremity shows that the brachial artery is near normal in caliber (arrow). (b) Axial image obtained a few sections distal to a shows narrowing of the brachial artery (arrow). (c) Next distal axial image shows loss of opacification of the brachial artery. (d) Coronal oblique reformatted image shows abrupt narrowing of the contrast material column in the brachial artery (arrow).
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Figure 4a. Loss of opacification of a segment of artery after blunt lower-extremity injury. (a) Sagittal reformatted CT angiographic image of the lower extremity shows loss of opacification of the popliteal artery (arrow) with distal reconstitution of arterial opacification. (b) Conventional arteriogram helps confirm loss of opacification of the popliteal artery (arrow).
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Figure 4b. Loss of opacification of a segment of artery after blunt lower-extremity injury. (a) Sagittal reformatted CT angiographic image of the lower extremity shows loss of opacification of the popliteal artery (arrow) with distal reconstitution of arterial opacification. (b) Conventional arteriogram helps confirm loss of opacification of the popliteal artery (arrow).
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Figure 5a. Arteriovenous fistula formation after penetrating lower-extremity injury. (a) Coronal oblique reformatted CT angiographic image of the lower extremity demonstrates an arteriovenous fistula arising from the superficial femoral artery that occurred after a gunshot wound to the thigh. (b) Digital subtraction image from conventional arteriography displays the injury in a similar projection. Both the CT angiogram and the arteriogram demonstrate the communication point between the artery and the vein (thin arrow) as well as the draining vein (thick arrow). A pseudoaneurysm (P) arising from the communication point is seen on both images.
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Figure 5b. Arteriovenous fistula formation after penetrating lower-extremity injury. (a) Coronal oblique reformatted CT angiographic image of the lower extremity demonstrates an arteriovenous fistula arising from the superficial femoral artery that occurred after a gunshot wound to the thigh. (b) Digital subtraction image from conventional arteriography displays the injury in a similar projection. Both the CT angiogram and the arteriogram demonstrate the communication point between the artery and the vein (thin arrow) as well as the draining vein (thick arrow). A pseudoaneurysm (P) arising from the communication point is seen on both images.
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Pitfalls in CT Angiography of the Extremities
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Poor arterial opacification may render a CT angiogram uninterpretable. Poorly timed initiation of scanning, either before the contrast material bolus has reached or after it has passed the arterial system in the extremity, may result in inadequate arterial opacification and render the CT angiogram nondiagnostic. Intravenous contrast material may circulate more slowly in patients with heart failure than in those in good cardiovascular health. A preset scanning initiation interval may not be long enough for these patients, and automated bolus tracking is desirable. However, the typical patient with a trauma-induced injury to an extremity is young and does not have co-morbid conditions that interfere with the timing of an intravenous contrast material bolus, so the preset time is adequate for most such patients.
We have occasionally observed technologists sampling the incorrect artery or sampling a vein with the automatic monitoring protocol for CT pulmonary angiograms. This mistake results in incorrect timing of scanning. CT angiography cannot be repeated with the same intravenous contrast material bolus after this mistake is discovered, because the bolus quickly leaves the arterial system. Opacification of the veins may interfere with interpretation of the CT angiogram if a second bolus is administered within several minutes of the mistimed initial bolus. We elect to perform conventional arteriography when there are errors in the administration of a contrast material bolus and scanning initiation. Each radiology department will have to decide whether it will have more success with preset scanning times or automated monitoring protocols similar to those used for CT pulmonary angiography. Contrast material extravasation at the injection site and failure of the injection equipment are other causes of poor arterial opacification.
Motion artifact can degrade the quality of a CT angiogram. Patients with trauma are more likely to be moving because of pain, altered mental status, or intoxication. To obtain a high-quality CT angiogram, it is important to immobilize the extremities. If a patient is unable to cooperate with CT angiography, we elect to perform conventional arteriography and we use sedation if necessary, monitored by the physician and nurse, to obtain a diagnostic study.
Streak artifacts are the major limiting factor in the ability of CT angiography to demonstrate arteries after penetrating missile injuries. The deposited metallic fragments may create streak artifacts that obscure the arteries, commonly at the exact location where the arterial injury is likely to occur. Figure 6 shows an example of streak artifact from metallic fragments obscuring the femoral artery. Most of the signs of arterial injury require direct visualization of the segment of injured artery. The performance of CT angiography in patients with retained metallic fragments near the injury has not been explored, because the published studies to date have excluded these patients from undergoing CT angiography (20–22).
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Figure 6a. Nondiagnostic CT angiogram with metallic streak artifact after shotgun injury to the lower extremity. (a) Axial CT angiographic image of the proximal portion of the thigh shows streak artifact from metallic shot pellets obscuring the arteries of the thigh. This CT angiogram is nondiagnostic. (b) Coronal reformatted image shows multiple segments of the superficial femoral artery obscured by streak artifact (arrow). (c) Conventional arteriogram clearly shows that the superficial femoral artery is intact and uninjured by the shot pellets.
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Figure 6b. Nondiagnostic CT angiogram with metallic streak artifact after shotgun injury to the lower extremity. (a) Axial CT angiographic image of the proximal portion of the thigh shows streak artifact from metallic shot pellets obscuring the arteries of the thigh. This CT angiogram is nondiagnostic. (b) Coronal reformatted image shows multiple segments of the superficial femoral artery obscured by streak artifact (arrow). (c) Conventional arteriogram clearly shows that the superficial femoral artery is intact and uninjured by the shot pellets.
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Figure 6c. Nondiagnostic CT angiogram with metallic streak artifact after shotgun injury to the lower extremity. (a) Axial CT angiographic image of the proximal portion of the thigh shows streak artifact from metallic shot pellets obscuring the arteries of the thigh. This CT angiogram is nondiagnostic. (b) Coronal reformatted image shows multiple segments of the superficial femoral artery obscured by streak artifact (arrow). (c) Conventional arteriogram clearly shows that the superficial femoral artery is intact and uninjured by the shot pellets.
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In our experience, CT angiograms in a few patients with deposited metal fragments in the extremity were still diagnostic because there was either loss of opacification distal to the site of injury or massive contrast material extravasation that could be seen despite the artifact, allowing for the confident diagnosis of arterial injury. In other cases, because of the trajectory of the bullet, the metallic fragments came to rest either proximal or distal to the arterial injury, so the streak artifact occurred in a different plane from the level of the injury. Figure 7 shows an example of an arterial injury that is easily seen despite metallic streak artifact in the extremity. Strict exclusion from CT angiography of patients with penetrating trauma and retained metallic fragments might eliminate patients who could benefit from diagnostic CT angiography. Conventional arteriography can still be performed after a nondiagnostic CT angiogram is obtained. The surgeons and radiologists at each institution will need to decide whether or not to attempt CT angiography or go straight to conventional arteriography in such cases.
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Figure 7a. Diagnostic CT angiogram with metallic streak artifact after penetrating lower-extremity injury. (a) Axial CT angiographic image of the middle portion of the thigh shows a metallic bullet fragment (B) causing a streak artifact that partially obscures the superficial femoral artery (arrow). (b) Axial image of the distal portion of the thigh shows a large pseudoaneurysm arising from the superficial femoral artery (arrow). The filling defect within the pseudoaneurysm is thrombus. (c) Axial image obtained a few sections distal to b shows either active contrast material extravasation or the edge of the pseudoaneurysm coming from the superficial femoral artery (arrow). (d) Oblique sagittal reformatted image of the thigh shows that the superficial femoral artery is obscured by metallic streak artifact in the middle portion of the thigh (short arrow), but the injury in the more distal part of the superficial femoral artery is clearly seen (long arrow). The bullet most likely entered the distal portion of the thigh and traveled superiorly, inflicting an arterial injury in a different axial plane than where the metallic bullet fragment rested and allowing for a diagnostic CT angiogram.
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Figure 7b. Diagnostic CT angiogram with metallic streak artifact after penetrating lower-extremity injury. (a) Axial CT angiographic image of the middle portion of the thigh shows a metallic bullet fragment (B) causing a streak artifact that partially obscures the superficial femoral artery (arrow). (b) Axial image of the distal portion of the thigh shows a large pseudoaneurysm arising from the superficial femoral artery (arrow). The filling defect within the pseudoaneurysm is thrombus. (c) Axial image obtained a few sections distal to b shows either active contrast material extravasation or the edge of the pseudoaneurysm coming from the superficial femoral artery (arrow). (d) Oblique sagittal reformatted image of the thigh shows that the superficial femoral artery is obscured by metallic streak artifact in the middle portion of the thigh (short arrow), but the injury in the more distal part of the superficial femoral artery is clearly seen (long arrow). The bullet most likely entered the distal portion of the thigh and traveled superiorly, inflicting an arterial injury in a different axial plane than where the metallic bullet fragment rested and allowing for a diagnostic CT angiogram.
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Figure 7c. Diagnostic CT angiogram with metallic streak artifact after penetrating lower-extremity injury. (a) Axial CT angiographic image of the middle portion of the thigh shows a metallic bullet fragment (B) causing a streak artifact that partially obscures the superficial femoral artery (arrow). (b) Axial image of the distal portion of the thigh shows a large pseudoaneurysm arising from the superficial femoral artery (arrow). The filling defect within the pseudoaneurysm is thrombus. (c) Axial image obtained a few sections distal to b shows either active contrast material extravasation or the edge of the pseudoaneurysm coming from the superficial femoral artery (arrow). (d) Oblique sagittal reformatted image of the thigh shows that the superficial femoral artery is obscured by metallic streak artifact in the middle portion of the thigh (short arrow), but the injury in the more distal part of the superficial femoral artery is clearly seen (long arrow). The bullet most likely entered the distal portion of the thigh and traveled superiorly, inflicting an arterial injury in a different axial plane than where the metallic bullet fragment rested and allowing for a diagnostic CT angiogram.
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Figure 7d. Diagnostic CT angiogram with metallic streak artifact after penetrating lower-extremity injury. (a) Axial CT angiographic image of the middle portion of the thigh shows a metallic bullet fragment (B) causing a streak artifact that partially obscures the superficial femoral artery (arrow). (b) Axial image of the distal portion of the thigh shows a large pseudoaneurysm arising from the superficial femoral artery (arrow). The filling defect within the pseudoaneurysm is thrombus. (c) Axial image obtained a few sections distal to b shows either active contrast material extravasation or the edge of the pseudoaneurysm coming from the superficial femoral artery (arrow). (d) Oblique sagittal reformatted image of the thigh shows that the superficial femoral artery is obscured by metallic streak artifact in the middle portion of the thigh (short arrow), but the injury in the more distal part of the superficial femoral artery is clearly seen (long arrow). The bullet most likely entered the distal portion of the thigh and traveled superiorly, inflicting an arterial injury in a different axial plane than where the metallic bullet fragment rested and allowing for a diagnostic CT angiogram.
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Slow blood flow distal to an arterial injury may limit runoff visualization of the arterial system in the distal part of the extremity at CT angiography as it does at conventional arteriography. This limitation may complicate planning for surgical repair of the arterial injury. The detection of injuries to distal, small-caliber arteries below the ankle or elbow is limited by the spatial resolution of CT angiography (14,21). Conventional arteriography still maintains a higher spatial resolution and continues to be the technique of choice for these arterial segments.
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Diagnostic Performance
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Three studies reported in the radiology and trauma literature have evaluated the performance of CT angiography in diagnosing arterial injuries to the extremities in trauma. In 1999, Soto et al (21) described a study in which patients referred for traditional arteriography after traumatic upper- and lower-extremity injury also underwent CT angiography. The sensitivity of CT angiography was 90%, and its specificity was 100%. Soto et al followed that study with a second prospective study reported in 2001 (20). In that study, CT angiography was used as the initial imaging modality in the setting of trauma to the extremities and showed a sensitivity of 95.1% and a specificity of 98.7% for proximal arterial injuries in the upper and lower extremities. The authors used long-term clinical follow-up, surgical exploration, and conventional arteriography as confirmation for positive or negative CT angiograms (20). In 2004 Busquets et al (22) published in the trauma literature a retrospective review of patients undergoing CT angiography for trauma to the extremities, reporting that 25 CT angiograms were proved positive and 10 were proved negative (22). Table 2 summarizes the results in these three series of cases. Our own experience with CT angiography agrees with these results. The high sensitivity and specificity of CT angiography of the extremities demonstrated in the literature show that this technique is a reliable initial diagnostic test for traumatic arterial injuries in the extremities.
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Summary
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CT angiography can be used to diagnose arterial injuries to the extremities rapidly and reliably in the setting of trauma, reducing the delay before repair of the injury. CT angiography is performed with multidetector CT scanners and rapid injection of intravenous contrast material to opacify the arteries. Signs of arterial injury include abrupt narrowing of an artery, loss of opacification of an arterial segment, pseudoaneurysm formation, active extravasation of contrast material, and arteriovenous fistula formation. CT angiograms may be rendered nondiagnostic by motion artifact, lack of opacification of the arteries, and metallic streak artifact. The resolution possible with four–detector row CT scanners may not be high enough to image intimal flap injuries and injuries to arteries distal to the elbow and ankle. Studies of CT angiography used to detect traumatic arterial injuries to the extremities have shown its sensitivity to be 90%–95.1% and its specificity to be 98.7%–100%. Radiologists and clinicians treating patients with trauma should consider using CT angiography to diagnose arterial injuries in the extremities.
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LEARNING OBJECTIVES FOR TEST...
