Imaging Pearls ❯ Vascular ❯ Run Off Studies (below iliacs)
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- “CTA is a frequently used first-line imaging study for the assessment of peripheral vascular trauma. CTA is usually readily available in emergency settings where trauma protocol CTs of the chest and abdomen are performed and is often faster and prone to less iatrogenic complications than conventional an- giography. Multiple specific manifestations of vascular trauma are readily demonstrated on CTA, which guide the next steps in patient management. Identification of these imaging signs is important to prevent devastating complications of vascular injury.”
Imaging primer for CT angiography in peripheral vascular trauma
Lara Walkoff et al.
Emergency Radiology (2021) 28:143–152 - "CTA is now widely accepted as the first-line imaging investigation when an upper or lower extremity vascular injury is in question. Compared with conventional angiography, CTA has the advantages of being less invasive, more readily avail- able, and allowing for the evaluation of the adjacent soft tissues and bones. CTA avoids potential iatrogenic complica- tions associated with catheter angiography, such as pseudoaneurysm, hematoma, thrombosis of the access vessel, and peripheral embolization. CTA is also less expensive and can be obtained quickly, as opposed to the delay often required to assemble a specialized team to perform conventional angiography, a particular advantage of CTA when reducing ischemic time is known to be an important factor in limb salvage.”
Imaging primer for CT angiography in peripheral vascular trauma
Lara Walkoff et al.
Emergency Radiology (2021) 28:143–152
- CT Angiography of the Lower Extremities: Applications
- Peripheral vascular disease
- Trauma
- Pre-operative planning
- Tumor staging and mapping
- Infectious disease - CT Angiography of the Lower Extremities: Applications
- Peripheral vascular disease (i.e. cold foot-r/o vessel stenosis)
- Trauma (i.e. GSW wound or stab wound)
- Pre-operative planning (fibula harvesting for mandibular reconstruction surgery)
- Tumor staging and mapping (evaluate mass for pre-operative planning)
- Infectious disease( R/O abscess, myonecrosis) - CT Angiography of the Lower Extremities: Pitfalls
- Poor injection rate (usually need 4-5 cc/sec)
- Poor timing of the acquisition (usually too early but may be too late)
- Patient motion
- Errors generated by the 3D rendering technique - CT Angiography of the Lower Extremities: Pearls
- use injection rate (usually need 4-5 cc/sec)
- Second run from just above knee in older patients with PVD
- Tape patient legs
- Use 3D after review of data and combine MIP, VRT and CR - “A modified three-material decomposition CS algorithm provides increased vascular CNR, equivalent qualitative image quality, and greater diagnostic accuracy for the detection of significant arterial stenosis of the lower extremity runoff on DE-CTA compared with standard image reconstruction.”
Modified calcium subtraction in dual-energy CT angiography of the lower extremity runoff: impact on diagnostic accuracy for stenosis detection.
De Santis D et al.
Eur Radiol. 2019 Sep;29(9):4783-4793 - "Calcified plaques may lead to overestimation of stenosis severity and false positive results, requiring additional invasive digital subtraction angiography (DSA). • A modified three-material decomposition algorithm for calcium subtraction provides greater diagnostic accuracy for the detection of significant arterial stenosis of the lower extremity runoff compared with standard image reconstruction. • The application of this algorithm in patients with heavily calcified vessels may be helpful to potentially reduce inconclusive CT angiography examinations and the need for subsequent invasive DSA."
Modified calcium subtraction in dual-energy CT angiography of the lower extremity runoff: impact on diagnostic accuracy for stenosis detection.
De Santis D et al.
Eur Radiol. 2019 Sep;29(9):4783-4793 - Background-—Poor lower extremity physical performance is an independent predictor of unfavorable outcome in patients with peripheral artery disease (PAD); however, few studies have assessed muscle characteristics on imaging directly.
Conclusions-—Low leg muscle density, but not volume, is a strong, independent predictor of major cardiovascular events among people with PAD. Further research is needed to understand the mechanisms underlying these associations.
Association of Computed Tomographic Leg Muscle Characteristics With Lower Limb and Cardiovascular Events in Patients With Peripheral Artery Disease
Morris DR et al.
J Am Heart Assoc. 2018;7:e009943. DOI:10.1161/JAHA.118.009943. - “Peripheral artery disease (PAD) is an important cause of premature death and disability, affecting over 200 mil- lion people worldwide. Patients with PAD have increased risk of leg amputation and cardiovascular events, such as myocardial infarction, stroke, and cardiovascular death. Even with current effective medical therapy, the risk of cardiovascular events is %3 times higher in patients with PAD compared with age- and sex- matched controls. More effective treatments are needed to reduce the high risk of lower limb and cardiovascular events in this population.”
Association of Computed Tomographic Leg Muscle Characteristics With Lower Limb and Cardiovascular Events in Patients With Peripheral Artery Disease
Morris DR et al.
J Am Heart Assoc. 2018;7:e009943. DOI:10.1161/JAHA.118.009943. 
Association of Computed Tomographic Leg Muscle Characteristics With Lower Limb and Cardiovascular Events in Patients With Peripheral Artery Disease
Morris DR et al.
J Am Heart Assoc. 2018;7:e009943. DOI:10.1161/JAHA.118.009943.- "Interestingly, low leg muscle density, but not volume, was independently associated with risk of major cardiovascular events. Previous studies demonstrate that decline in muscle strength in older adults is much more rapid than concomitant loss of muscle mass. This could explain why low muscle density, but not volume, was independently associated with risk of major cardiovascular events. Another possible expla- nation is that low muscle density may result from myocyte fat infiltration, which could influence cardiometabolic risk through pro-inflammatory adipokines. Factors contributing to muscle density on CT imaging are not well established."
Association of Computed Tomographic Leg Muscle Characteristics With Lower Limb and Cardiovascular Events in Patients With Peripheral Artery Disease
Morris DR et al.
J Am Heart Assoc. 2018;7:e009943. DOI:10.1161/JAHA.118.009943. - "In conclusion, this study showed a strong association between low leg muscle density and clinical events in patients with PAD. Further research is needed to better understand the reasons for this association."
Association of Computed Tomographic Leg Muscle Characteristics With Lower Limb and Cardiovascular Events in Patients With Peripheral Artery Disease
Morris DR et al.
J Am Heart Assoc. 2018;7:e009943. DOI:10.1161/JAHA.118.009943. - Purpose: The purpose of this study is to assess the performance of CT angiography (CTA) in the evaluation of penetrating vascular trauma to the extremities in a large cohort of patients at our level I trauma center.
Results: One hundred and thirty-one (29.4 %) of 446 patients with penetrating trauma demonstrated major vascular injury on CTA, 35 (26.7 %) of whom underwent subsequent surgical repair. None of the patients without vascular injury on CTA underwent subsequent vascular intervention. Fisher’s exact test demonstrated a statistically significant difference in management and requirement for vascular repair in those patients with a vascular injury on CTA when compared to those without a vascular injury (p < 0.0001). The mean attenuation values achieved in upper and lower extremity CTAs in this population exceeded 250 HU.
Conclusion: Extremity CTA is found to be an accurate tool for surgical triage in patients having sustained penetrating vascular trauma.
Extremity CTA for penetrating trauma: 10-year experience using a 64-detector row CT scanner.
Colip CG et al.
Emerg Radiol. 2017 Jun;24(3):223-232. - Aim: To evaluate run-off computed tomography angiography (CTA) of abdominal aorta and lower extremities for detecting musculoskeletal pathologies and clinically relevant extravascular incidental findings in patients with intermittent claudication (IC) and suspected peripheral arterial disease (PAD). Does run-off CTA allow image-based therapeutic decision making by discriminating the causes of intermittent claudication in patients with suspected peripheral arterial disease PAD?
Discussion: Run-off CTA allows identification of vascular, MSK, and combined causes of IC in patients with suspected PAD and can guide specific therapy. CTA also allowed confident detection of crEVIF although detection did not necessarily trigger workup or treatment.
Run-Off Computed Tomography Angiography (CTA) for Discriminating the Underlying Causes of Intermittent Claudication
Alexandra Preuß et al.
PLoS One. 2016 Apr 7;11(4):e0152780. doi: 10.1371/journal.pone.0152780 - “Run-off computed tomography angiography (CTA) has become the method of choice for non-invasive imaging of the aorta and lower limb vessels in patients with suspected PAD and is considered to be more accurate than arterial duplex sonography. While still considered the diagnostic standard of reference for PAD, digital subtraction angiography (DSA) is currently being replaced by non-invasive imaging techniques such as CTA or magnetic resonance angiography (MRA). Several studies have shown that CTA is highly accurate in detecting arterial stenosis while avoiding common complications associated with invasive DSA [9]. Furthermore, CTA has become widely used because it is fast and well tolerated by patients and allows precise treatment planning even when using low-dose protocols.”
Run-Off Computed Tomography Angiography (CTA) for Discriminating the Underlying Causes of Intermittent Claudication
Alexandra Preuß et al.
PLoS One. 2016 Apr 7;11(4):e0152780. doi: 10.1371/journal.pone.0152780 - "Although the focus is on vascular assessment, run-off CT angiography of the aorta and lower extremities also allows differentiation of vascular and musculoskeletal causes of intermittent claudication in a single examination. It facilitates therapeutic decision-making since a considerable number of patients have clinically relevant musculoskeletal findings such as lumbar spinal stenosis or combined vascular and musculoskeletal pathology. Clinically relevant extravascular incidental findings are common on run-off CTA and can be identified on the basis of their CT morphology."
Run-Off Computed Tomography Angiography (CTA) for Discriminating the Underlying Causes of Intermittent Claudication
Alexandra Preuß et al.
PLoS One. 2016 Apr 7;11(4):e0152780. doi: 10.1371/journal.pone.0152780 - “A low-tube-voltage scan protocol allows for a significant reduction of the injected CM volume and the acquired radiation dose, while maintaining sufficient objective and subjective image quality for the evaluation of PAD, regardless of the lesion severity.”
CT Angiography in the Lower Extremity Peripheral Artery Disease Feasibility of an Ultra-Low Volume Contrast Media Protocol
Barbora Horehledova et al.
Cardiovasc Intervent Radiol (2018) 41:1751–1764 - “Fleischmann et al. [25] recommend to prolong the injection duration with a corresponding increase in the scan delay to allow an adequate filling distal to the occluded segment. Overall high attenuation values suggest the possibility to reduce CM concentration by mixing the main bolus with saline in order to increase injection volume to prolong the injection time, while the TIL stays the same. The optimum CM volume, concentration, iodine delivery rate (IDR) and injection time for satisfactory attenuation in DPA need to be clarified in a further study. However, the cases with high complete vascular occlusion at the level of CIA or SFA demonstrated that the double-level test bolus technique is able to overcome such severe occlusion, while delivering diagnostic attenuation in all PA and 10/11 ATA segments.”
CT Angiography in the Lower Extremity Peripheral Artery Disease Feasibility of an Ultra-Low Volume Contrast Media Protocol
Barbora Horehledova et al.
Cardiovasc Intervent Radiol (2018) 41:1751–1764
- CT Angiography of the Lower Extremities: Applications
- Peripheral vascular disease
- Trauma
- Pre-operative planning
- Tumor staging and mapping
- Infectious disease - CT Angiography of the Lower Extremities: Applications
- Peripheral vascular disease (i.e. cold foot-r/o vessel stenosis)
- Trauma (i.e. GSW wound or stab wound)
- Pre-operative planning (fibula harvesting for mandibular reconstruction surgery)
- Tumor staging and mapping (evaluate mass for pre-operative planning)
- Infectious disease( R/O abscess, myonecrosis) - CT Angiography of the Lower Extremities: Pitfalls
- Poor injection rate (usually need 4-5 cc/sec)
- Poor timing of the acquisition (usually too early but may be too late)
- Patient motion
- Errors generated by the 3D rendering technique - CT Angiography of the Lower Extremities: Pearls
- use injection rate (usually need 4-5 cc/sec)
- Second run from just above knee in older patients with PVD
- Tape patient legs
- Use 3D after review of data and combine MIP, VRT and CR - “A modified three-material decomposition CS algorithm provides increased vascular CNR, equivalent qualitative image quality, and greater diagnostic accuracy for the detection of significant arterial stenosis of the lower extremity runoff on DE-CTA compared with standard image reconstruction.”
Modified calcium subtraction in dual-energy CT angiography of the lower extremity runoff: impact on diagnostic accuracy for stenosis detection.
De Santis D et al.
Eur Radiol. 2019 Sep;29(9):4783-4793 - "Calcified plaques may lead to overestimation of stenosis severity and false positive results, requiring additional invasive digital subtraction angiography (DSA). • A modified three-material decomposition algorithm for calcium subtraction provides greater diagnostic accuracy for the detection of significant arterial stenosis of the lower extremity runoff compared with standard image reconstruction. • The application of this algorithm in patients with heavily calcified vessels may be helpful to potentially reduce inconclusive CT angiography examinations and the need for subsequent invasive DSA."
Modified calcium subtraction in dual-energy CT angiography of the lower extremity runoff: impact on diagnostic accuracy for stenosis detection.
De Santis D et al.
Eur Radiol. 2019 Sep;29(9):4783-4793 - Background-—Poor lower extremity physical performance is an independent predictor of unfavorable outcome in patients with peripheral artery disease (PAD); however, few studies have assessed muscle characteristics on imaging directly.
Conclusions-—Low leg muscle density, but not volume, is a strong, independent predictor of major cardiovascular events among people with PAD. Further research is needed to understand the mechanisms underlying these associations.
Association of Computed Tomographic Leg Muscle Characteristics With Lower Limb and Cardiovascular Events in Patients With Peripheral Artery Disease
Morris DR et al.
J Am Heart Assoc. 2018;7:e009943. DOI:10.1161/JAHA.118.009943. - “Peripheral artery disease (PAD) is an important cause of premature death and disability, affecting over 200 mil- lion people worldwide. Patients with PAD have increased risk of leg amputation and cardiovascular events, such as myocardial infarction, stroke, and cardiovascular death. Even with current effective medical therapy, the risk of cardiovascular events is %3 times higher in patients with PAD compared with age- and sex- matched controls. More effective treatments are needed to reduce the high risk of lower limb and cardiovascular events in this population.”
Association of Computed Tomographic Leg Muscle Characteristics With Lower Limb and Cardiovascular Events in Patients With Peripheral Artery Disease
Morris DR et al.
J Am Heart Assoc. 2018;7:e009943. DOI:10.1161/JAHA.118.009943.
Association of Computed Tomographic Leg Muscle Characteristics With Lower Limb and Cardiovascular Events in Patients With Peripheral Artery Disease
Morris DR et al.
J Am Heart Assoc. 2018;7:e009943. DOI:10.1161/JAHA.118.009943.- "Interestingly, low leg muscle density, but not volume, was independently associated with risk of major cardiovascular events. Previous studies demonstrate that decline in muscle strength in older adults is much more rapid than concomitant loss of muscle mass. This could explain why low muscle density, but not volume, was independently associated with risk of major cardiovascular events. Another possible expla- nation is that low muscle density may result from myocyte fat infiltration, which could influence cardiometabolic risk through pro-inflammatory adipokines. Factors contributing to muscle density on CT imaging are not well established."
Association of Computed Tomographic Leg Muscle Characteristics With Lower Limb and Cardiovascular Events in Patients With Peripheral Artery Disease
Morris DR et al.
J Am Heart Assoc. 2018;7:e009943. DOI:10.1161/JAHA.118.009943. - "In conclusion, this study showed a strong association between low leg muscle density and clinical events in patients with PAD. Further research is needed to better understand the reasons for this association."
Association of Computed Tomographic Leg Muscle Characteristics With Lower Limb and Cardiovascular Events in Patients With Peripheral Artery Disease
Morris DR et al.
J Am Heart Assoc. 2018;7:e009943. DOI:10.1161/JAHA.118.009943. - Purpose: The purpose of this study is to assess the performance of CT angiography (CTA) in the evaluation of penetrating vascular trauma to the extremities in a large cohort of patients at our level I trauma center.
Results: One hundred and thirty-one (29.4 %) of 446 patients with penetrating trauma demonstrated major vascular injury on CTA, 35 (26.7 %) of whom underwent subsequent surgical repair. None of the patients without vascular injury on CTA underwent subsequent vascular intervention. Fisher’s exact test demonstrated a statistically significant difference in management and requirement for vascular repair in those patients with a vascular injury on CTA when compared to those without a vascular injury (p < 0.0001). The mean attenuation values achieved in upper and lower extremity CTAs in this population exceeded 250 HU.
Conclusion: Extremity CTA is found to be an accurate tool for surgical triage in patients having sustained penetrating vascular trauma.
Extremity CTA for penetrating trauma: 10-year experience using a 64-detector row CT scanner.
Colip CG et al.
Emerg Radiol. 2017 Jun;24(3):223-232. - Aim: To evaluate run-off computed tomography angiography (CTA) of abdominal aorta and lower extremities for detecting musculoskeletal pathologies and clinically relevant extravascular incidental findings in patients with intermittent claudication (IC) and suspected peripheral arterial disease (PAD). Does run-off CTA allow image-based therapeutic decision making by discriminating the causes of intermittent claudication in patients with suspected peripheral arterial disease PAD?
Discussion: Run-off CTA allows identification of vascular, MSK, and combined causes of IC in patients with suspected PAD and can guide specific therapy. CTA also allowed confident detection of crEVIF although detection did not necessarily trigger workup or treatment.
Run-Off Computed Tomography Angiography (CTA) for Discriminating the Underlying Causes of Intermittent Claudication
Alexandra Preuß et al.
PLoS One. 2016 Apr 7;11(4):e0152780. doi: 10.1371/journal.pone.0152780 - “Run-off computed tomography angiography (CTA) has become the method of choice for non-invasive imaging of the aorta and lower limb vessels in patients with suspected PAD and is considered to be more accurate than arterial duplex sonography. While still considered the diagnostic standard of reference for PAD, digital subtraction angiography (DSA) is currently being replaced by non-invasive imaging techniques such as CTA or magnetic resonance angiography (MRA). Several studies have shown that CTA is highly accurate in detecting arterial stenosis while avoiding common complications associated with invasive DSA [9]. Furthermore, CTA has become widely used because it is fast and well tolerated by patients and allows precise treatment planning even when using low-dose protocols.”
Run-Off Computed Tomography Angiography (CTA) for Discriminating the Underlying Causes of Intermittent Claudication
Alexandra Preuß et al.
PLoS One. 2016 Apr 7;11(4):e0152780. doi: 10.1371/journal.pone.0152780 - "Although the focus is on vascular assessment, run-off CT angiography of the aorta and lower extremities also allows differentiation of vascular and musculoskeletal causes of intermittent claudication in a single examination. It facilitates therapeutic decision-making since a considerable number of patients have clinically relevant musculoskeletal findings such as lumbar spinal stenosis or combined vascular and musculoskeletal pathology. Clinically relevant extravascular incidental findings are common on run-off CTA and can be identified on the basis of their CT morphology."
Run-Off Computed Tomography Angiography (CTA) for Discriminating the Underlying Causes of Intermittent Claudication
Alexandra Preuß et al.
PLoS One. 2016 Apr 7;11(4):e0152780. doi: 10.1371/journal.pone.0152780 - “A low-tube-voltage scan protocol allows for a significant reduction of the injected CM volume and the acquired radiation dose, while maintaining sufficient objective and subjective image quality for the evaluation of PAD, regardless of the lesion severity.”
CT Angiography in the Lower Extremity Peripheral Artery Disease Feasibility of an Ultra-Low Volume Contrast Media Protocol
Barbora Horehledova et al.
Cardiovasc Intervent Radiol (2018) 41:1751–1764 - “Fleischmann et al. [25] recommend to prolong the injection duration with a corresponding increase in the scan delay to allow an adequate filling distal to the occluded segment. Overall high attenuation values suggest the possibility to reduce CM concentration by mixing the main bolus with saline in order to increase injection volume to prolong the injection time, while the TIL stays the same. The optimum CM volume, concentration, iodine delivery rate (IDR) and injection time for satisfactory attenuation in DPA need to be clarified in a further study. However, the cases with high complete vascular occlusion at the level of CIA or SFA demonstrated that the double-level test bolus technique is able to overcome such severe occlusion, while delivering diagnostic attenuation in all PA and 10/11 ATA segments.”
CT Angiography in the Lower Extremity Peripheral Artery Disease Feasibility of an Ultra-Low Volume Contrast Media Protocol
Barbora Horehledova et al.
Cardiovasc Intervent Radiol (2018) 41:1751–1764
- Purpose: To compare diagnostic performance of MDCTA vs MRA before endovascular intervention.
Results: MDCTA and MRA accurately classify disease in the aorto-iliac (accuracy 0.92 for MDCTA and MRA) and femoro-popliteal (MDCTA 0.94, MRA 0.90) segments. MDCTA was more accurate in stratifying disease in the infra- popliteal segments (0.96 vs. 0.9) and in assessing the impairment of runoff arteries (0.92 vs. 0.85) at per-segment analysis. MDCTA showed a higher confidence and a shorter examination time.
Conclusion: Our results suggest that MDCTA can be considered as a first-line investigation in patients being candidates for endovascular procedures when clinical history or duplex sonographic evaluation are indicative of severe impairment of the infrapopliteal segment.
Comparison of CT and MR angiography in evaluation of peripheral arterial disease before endovascular intervention
Cina A et al
Acta Radiologica 2016, Vol. 57(5) 547–556 - Purpose: To evaluate the diagnostic performance and effect on therapeutic management of 64-section computed tomographic (CT) angiography in the assessment of steno-occlusive disease in patients with peripheral arterial disease (PAD), with conventional digital subtraction angiography (DSA) as the reference standard.
Conclusion: The diagnostic performance of 64-section CT angiography is excellent in patients with clinical symptoms of PAD. The results can be used to effectively guide therapeutic decision making in these patients.
Peripheral Arterial Occlusive Disease: Diagnostic Performance and Effect on Therapeutic Management of 64-Section CT Angiography
Napoli A et al.
Radiology 2011; 261:976–986 - Objective: Preprocedural computed tomography angiography (CTA) assists in evaluating vascular morphology and disease distribution and in treatment planning for patients with lower extremity peripheral artery disease (PAD). The aim of the study was to determine the predictive value of radiographic findings on CTA and technical success of endovascular revascularization of occlusions in the superficial femoral artery-popliteal (SFA-pop) region.
Conclusions: Analysis of preoperative CTA shows 100% calcification as the best predictor of technical failure of endo- vascular revascularization of occlusions in the SFA-pop region. Further studies are needed to determine the cost-effectiveness of obtaining preoperative CTA for lower extremity PAD.
Lower extremity computed tomography angiography can help predict technical success of endovascular revascularization in the superficial femoral and popliteal artery
Itoga NK et al.
J Vasc Surg 2017;66:835-43 - “This study demonstrated 100% vessel calcification as the best predictor of technical failure in endovascular treatment of occlusions in the SFA-pop region. As advances in catheter-based technology and noninvasive radiographic imaging continue to evolve, future guidelines may consider noninvasive imaging in the preopera- tive assessment to help guide treatment strategies.”
Lower extremity computed tomography angiography can help predict technical success of endovascular revascularization in the superficial femoral and popliteal artery
Itoga NK et al.
J Vasc Surg 2017;66:835-43 - Take Home Message: In a study of 540 endovascular procedures, multivariable analysis revealed that 100% calcification on preoperative computed tomography angiography is the only significant predictor of technical failure (odds ratio, 9.0; 95% confidence interval, 1.8-45.8; P 1⁄4 .008).
Recommendation: The authors suggest that 100% of vessel calcification on preoperative computed tomography angiography is the best predictor of technical failure in revascularization of superficial femoral and popliteal artery occlusions.
Lower extremity computed tomography angiography can help predict technical success of endovascular revascularization in the superficial femoral and popliteal artery
Itoga NK et al.
J Vasc Surg 2017;66:835-43 - CTA in Clinical Practice: Advantages
- Less patient compliance needed
- Study protocols easier to define across and enterprise
- Lower cost to the patient and health system
- Better reproducibility across sequential studies
- Ability to deal with stents and grafts with definition of muscle and soft tissue without special sequences
- Availability in ER setting 24/7 - CTA Success is Dependent On;
- Scan protocols and scanner technology including Dual Energy CT provide flexibility including decreased contrast volumes
- Delivery of IV contrast (timing and injection protocols)
- Use of Post Processing Techniques (Curved Planar Reconstrution, MIP, VRT, CR)
- “CTA of the lower extremities is an important and versatile noninvasive tool for diagnosis as well as surgical or endovascular interventional planning. Although lower extremity CTA is most commonly performed in patients who suffer from PAD or trauma affecting the lower extremities, it also plays a role in the workup of nonischemic etiologies and congenital vascular malformations. CT scanner protocols should adjust bolus timing and multi- phasic imaging to account for the clinical question of interest, and 3-dimensional postprocessing plays an important role in the visualization and interpretation of these high-resolution imaging examinations.”
Computed Tomography Angiography of the Lower Extremities Cook TS Radiol Clin N Am 54 (2016) 115–130 - “Trauma to the lower extremities can occur from blunt or penetrating causes. Blunt trauma includes motor vehicle collisions, falls, athletic injuries, and occupational injuries, and is often associated with severe pelvic, femoral, and/or tibial fractures. Penetrating trauma may occur secondary to ballistics, shrapnel, or low-velocity sharp objects, and may or may not affect the bones of the extremity depending on the trajectory of the ballistic missile. Arterial injury in the setting of trauma may result in active extravasation, subcutaneous or intramuscular hematoma, pseudoaneurysm, vessel narrowing/stretching, occlusion, or arteriovenous fistula.”
Computed Tomography Angiography of the Lower Extremities Cook TS Radiol Clin N Am 54 (2016) 115–130
- “CTA of the lower extremities is an important and versatile noninvasive tool for diagnosis as well as surgical or endovascular interventional planning. Although lower extremity CTA is most commonly performed in patients who suffer from PAD or trauma affecting the lower extremities, it also plays a role in the workup of nonischemic etiologies and congenital vascular malformations. CT scanner protocols should adjust bolus timing and multi- phasic imaging to account for the clinical question of interest, and 3-dimensional postprocessing plays an important role in the visualization and interpretation of these high-resolution imaging examinations.”
Computed Tomography Angiography of the Lower Extremities Cook TS Radiol Clin N Am 54 (2016) 115–130 - “Trauma to the lower extremities can occur from blunt or penetrating causes. Blunt trauma includes motor vehicle collisions, falls, athletic injuries, and occupational injuries, and is often associated with severe pelvic, femoral, and/or tibial fractures. Penetrating trauma may occur secondary to ballistics, shrapnel, or low-velocity sharp objects, and may or may not affect the bones of the extremity depending on the trajectory of the ballistic missile. Arterial injury in the setting of trauma may result in active extravasation, subcutaneous or intramuscular hematoma, pseudoaneurysm, vessel narrowing/stretching, occlusion, or arteriovenous fistula.”
Computed Tomography Angiography of the Lower Extremities Cook TS Radiol Clin N Am 54 (2016) 115–130
- “The popliteal artery is located behind the knee in the popliteal fossa and is a direct extension of the superficial femoral artery after it passes through the adductor hiatus, an opening in the tendinous slip of the great adductor muscle of the thigh. The popliteal artery lies posterior to the femur and anterior to the popliteal vein. The popliteal artery and vein are normally located between the two heads of the gastrocnemius muscle.”
Popliteal Artery Disease: Diagnosis and Treatment
Wright LB et al.
RadioGraphics, Mar 2004, Vol. 24:467–479 - “The popliteal artery and vein are normally located between the two heads of the gastrocnemius muscle. Abnormalities in this relationship can produce popliteal artery entrapment syndrome (PAES). In the region of the knee, the popliteal artery gives off genicular and sural branches, eventually dividing into the anterior tibial artery and the tibioperoneal trunk. The tibioperoneal trunk further subdivides into the posterior tibial and peroneal arteries. The proximity of the popliteal artery to the distal femur makes it susceptible to injury when the distal femur is fractured or the knee is dislocated.”
Popliteal Artery Disease: Diagnosis and Treatment
Wright LB et al.
RadioGraphics, Mar 2004, Vol. 24:467–479 - “Atherosclerosis is the leading cause of morbidity and mortality in the United States and is the most common cause of popliteal artery occlusion or stenosis. The pathogenesis of atherosclerosis is well established. Endothelial injury initiates a process whereby overproduction of cellular mediators eventually produces fibrotic plaque. This plaque may calcify, fracture, ulcerate, hemorrhage, and ultimately limit blood flow or cause thrombosis of the vessel.”
Popliteal Artery Disease: Diagnosis and Treatment
Wright LB et al.
RadioGraphics, Mar 2004, Vol. 24:467–479 - “Generally, aneurysms can be categorized as either true or false. True aneurysms occur when all layers of the arterial wall are abnormally dilated. False aneurysms (pseudoaneurysms) are due to a defect in the arterial wall related to trauma or (mycotic) infection. Trauma may be related to iatrogenic injury due to surgery or intervention.”
Popliteal Artery Disease: Diagnosis and Treatment
Wright LB et al.
RadioGraphics, Mar 2004, Vol. 24:467–479 - “The popliteal artery is considered aneurysmal if its diameter exceeds 0.7 cm. Aneurysms may rarely be associated with connective tissue diseases such as Marfan syndrome or Ehlers-Danlos syndrome or, even more rarely, with pregnancy. Almost all true aneurysms are nonspecific. Historically, the nonspecific form of aneurysmal disease that affects the abdominal aorta and the iliac, femoral, and popliteal arteries has been described as “atherosclerotic.”
Popliteal Artery Disease: Diagnosis and Treatment
Wright LB et al.
RadioGraphics, Mar 2004, Vol. 24:467–479 - “About 45% of patients with PAAs are asymptomatic at the time of diagnosis. Symptomatic patients present with lower-extremity ischemia, which can manifest as claudication, rest pain, or severe ischemia associated with thrombosis or embolization.”
Popliteal Artery Disease: Diagnosis and Treatment
Wright LB et al.
RadioGraphics, Mar 2004, Vol. 24:467–479 - “The popliteal artery is susceptible to injury due to its proximity to the distal femur and knee joint. Anterior and posterior knee dislocations as well as fractures are often associated with popliteal artery injury. Popliteal artery occlusion is seen in 30%–50% of patients with complete knee dislocation. In today’s society, such injuries are most commonly caused by motor vehicle accidents, but injury related to penetrating trauma is not uncommon. These traumatic injuries include laceration, dissection, occlusion, and posttraumatic pseudoaneurysm formation . Trauma affecting the popliteal artery and vein will occasionally produce an arteriovenous fistula.”
Popliteal Artery Disease: Diagnosis and Treatment
Wright LB et al.
RadioGraphics, Mar 2004, Vol. 24:467–479 - “The popliteal artery, like any other peripheral artery, can be affected by embolism. Macroemboli have a tendency to lodge in the popliteal artery at the bifurcation into the tibioperoneal trunk and anterior tibial artery. An embolus in the lower extremities most often has a cardiac source. Other sources include aortic aneurysms and proximal arterial plaque or ulceration. Regardless of the source, acute arterial embolism almost always requires urgent treatment.”
Popliteal Artery Disease: Diagnosis and Treatment
Wright LB et al.
RadioGraphics, Mar 2004, Vol. 24:467–479 - “PAES is a developmental abnormality that results from an abnormal relationship of the popliteal artery to the gastrocnemius muscle or, rarely, an anomalous fibrous band or the popliteus muscle. The abnormal position causes deviation and compression of the artery. There are essentially four anatomic variants of PAES. Type V is any of the four anatomic variants that includes the popliteal vein .”
Popliteal Artery Disease: Diagnosis and Treatment
Wright LB et al.
RadioGraphics, Mar 2004, Vol. 24:467–479
- “The popliteal artery is a relatively short vascular segment but is affected by a unique set of pathologic conditions. These conditions, which may be common throughout the arterial system or exclusive to the popliteal artery, include atherosclerosis, popliteal artery aneurysm, arterial embolus, trauma, popliteal artery entrapment syndrome, and cystic adventitial disease. The clinical manifestations, imaging appearances, and treatment options associated with these pathologic conditions differ significantly.”
Popliteal Artery Disease: Diagnosis and Treatment
Wright LB et al.
March 2004 RadioGraphics 24:467-479 - “The popliteal artery is considered aneurysmal if its diameter exceeds 0.7 cm. Aneurysms may rarely be associated with connective tissue diseases such as Marfan syndrome or Ehlers-Danlos syndrome or, even more rarely, with pregnancy. Almost all true aneurysms are nonspecific. Historically, the nonspecific form of aneurysmal disease that affects the abdominal aorta and the iliac, femoral, and popliteal arteries has been described as “atherosclerotic.” Risk factors associated with atherosclerotic disease are also associated with nonspecific aneurysms.”
Popliteal Artery Disease: Diagnosis and Treatment
Wright LB et al.
March 2004 RadioGraphics 24:467-479 - “Popliteal artery aneurysms (PAAs) are relatively uncommon compared with abdominal aortic aneurysms (AAAs), but recent studies have identified an increase in the prevalence of PAAs that may be due to greater access to imaging modalities such as US. Consequently, reports vary as to the ratio of PAAs to AAAs, which ranges from 1:8 to 1:23 (8,9). PAAs are associated with aneurysms in other locations. An AAA is present in 30%–50% of patients with a PAA.”
Popliteal Artery Disease: Diagnosis and Treatment
Wright LB et al.
March 2004 RadioGraphics 24:467-479 - “PAAs can be complicated by thrombosis, distal embolization of thrombotic material, and, rarely, rupture. Studies have shown that complications occur in 18%–31% of such aneurysms that were not corrected surgically . Thrombolytic therapy is often required in patients who present with acute thrombosis to recanalize the distal popliteal and trifurcation vessels as targets for bypass surgery . Despite the thrombus burden present within popliteal aneurysms, thrombolytic therapy is very successful in patients who can withstand an additional period of ischemia .”
Popliteal Artery Disease: Diagnosis and Treatment
Wright LB et al.
March 2004 RadioGraphics 24:467-479
- “ Of patients undergoing CT angiography of the abdominal aorta and lower extremities, 15% had previously undiagnosed, highly important findings. Radiologists and referring clinicians should be aware of the frequency of these clinically significant extravascular findings at CT angiography.”
Incidence of Highly Important Extravascular Findings Detected on CT Angiography of the Abdominal Aorta an the Lower Extremities
Naidu S et al.
AJR 2010 194:1630-1634 - “ Reports of CT angiograms of the abdominal aorta and lower extremities for 275 patients (164 men and 111 women; mean age 72 years) were retrospectively reviewed. Extravascular findings were classified into three groups-low, moderate and high importance-on the basis of clinical significance.”
Incidence of Highly Important Extravascular Findings Detected on CT Angiography of the Abdominal Aorta an the Lower Extremities
Naidu S et al.
AJR 2010 194:1630-1634 - “ Highly important extravascular findings were found in 40 (15%) patients. Of 462 findings overall, 43 (9%) were of high importance, 77 (17%) were of moderate importance, and 342 (74%) were of low importance. The most common highly important findings were indeterminate lesions of the kidney (n=9), lung (n=7) and liver (n=6).”
Incidence of Highly Important Extravascular Findings Detected on CT Angiography of the Abdominal Aorta an the Lower Extremities
Naidu S et al.
AJR 2010’194:1630-1634 - “ Highly important extravascular findings were found in 40 (15%) patients. Of 462 findings overall, 43 (9%) were of high importance, 77 (17%) were of moderate importance, and 342 (74%) were of low importance. The most common highly important findings were indeterminate lesions of the kidney (n=9), lung (n=7) and liver (n=6). Overall eight (3%) of the 275 patients had findings of high clinical significance that resulted in medical therapy or surgical intervention, including lung carcinoma, renal cell carcinoma, colon carcinoma, cholangiocarcinoma, and pulmonary coccidiomycosis.”
Incidence of Highly Important Extravascular Findings Detected on CT Angiography of the Abdomonal Aorta an the Lower Extremities
Naidu S et al.
AJR 2010 194:1630-1634
- “Compared with digital subtraction angiography, sensitivity, specificity, and accuracy, respectively, of CTA was 97.2%, 94.1%, and 94.7% by the dual-energy bone removal technique. The conventional bone removal tool delivered a sensitivity of 77.1%, a specificity of 70.7%, and an accuracy of 72.0%.”
Dual-energy CT angiography in peripheral arterial occlusive disease
Brockmann C et al.
Cardiovasc Intervent radiol 2009 Jul;32(4):630-7 - “ DE-CTA is a feasible and accurate diagnostic method in the assessment of symptomatic peripheral arterial occlusive disease. Results obtained by DE-CTA are superior to the conventional bone removal technique and less dependent on vessel wall calcifications.”
Dual-energy CT angiography in peripheral arterial occlusive disease
Brockmann C et al.
Cardiovasc Intervent radiol 2009 Jul;32(4):630-7 "Our data suggests that 64-slice MDCT could be used to assess the abdominal aorta and lower extremity arteries with a reduction of table speed to allow adequate arterial opacification and minimal venous contamination. We recommend different table speeds for each patient age group as a guideline for routine CTA of the lower extremity."
Optimization of the table speed of lower extremity CT angiography protocols in different patient age groups
Siriapisith T et al.
J Cardiovasc Comput Tomogr (2010) 4, 173-183"The test injection using a monitoring scan at knee level was found to be useful for 64-slice MDCT angiography of the abdominal and lower extremity arteries."
64-Slice Multidetector Row Computed Tomographic Angiography of Aortoiliac and Lower Extremity Arteries: Efficacy of test Injection Using a Monitoring Scan at Knee level
Nakaya Y et al.
J Comput Assist Tomogr 2009;33: 20-25- "In cases of significant penetrating and blunt trauma to the large arteries of the proximal extremities, CTA has shown a sensitivity of 95.1% and a specificity of 98.7%"
Femoral Artery Occlusion after Blunt Trauma: Diagnosis by Multislice CT Angiography
Chen JK, Johnson PT, Fishman EK
Emerg Radiol (2006) 12:244-245.
- Multidetector row CT allows reliable assessment of anatomic relationships between the lesion and the aortic branches as well as evaluation of the iliac and femoral arteries (diameter,tortuosity) for vascular access.
Stent-Graft Placement for the Treatment of Thoracic Aortic Disease
Therasse E et al. RadioGraphicss 2005; 25:157-173
- "Multidetector CT angiography is an accurate, noninvasive technique for the imaging of peripheral vascular disease."
Multidetector CT Angiography of Peripheral Vascular Disease: A Prospective Comparison with Intraarterial Digital Subtraction Angiography
Ofer A et al.
AJR 2003; 180:719-724
- "Multidetector CT angiography is an accurate, noninvasive technique for the imaging of peripheral vascular disease. Compared with DSA, CT angiography yielded a sensitivity of 90.9% and a specificity of 92.4%"
Multidetector CT Angiography of Peripheral Vascular Disease: A Prospective Comparison with Intraarterial Digital Subtraction Angiography
Ofer A et al.
AJR 2003; 180:719-724
- "Multidetector row CT angiography may be an accurate and reliable technique after duplex US in the assessment of peripheral arterial bypass grafts and detection of graft related complications, including stenosis, aneurysmal changes, and arteriovenous fistulas."
Evaluation of Peripheral Arterial Bypass Grafts with Multidetector Row CT Angiography: Comparison with Duplex US and Digital Subtraction Angiography
Willmann JK et al.
Radiology 2003; 229:465-474
- "MDCT angiography was accurate in showing arterial atheroocclusive disease with reliability similar to DSA. MDCT angiography showed more vascular segments than DSA, particularly within calf vessels."
Multidetector CT Angiography of the Aortoiliac System and Lower Extremities: A Prospective Comparison with Digital Subtraction Angiography
Martin ML et al.
AJR 2003; 180:1085-1091
- "MDCT angiography is a reliable method for evaluating the aortoiliac and lower extremity arteries."
MDCT Compared with DSA for Assessment of Lower Extremity Arterial Occlusive Disease: Importance of Reviewing Cross-Sectional Images
Ota H et al.
AJR 2004; 182:201-209
- MDCT Angiography of the Lower Extremities: Limitations
- Timing of injection
- Dense calcifications
- Difficulty in edited lower leg vessels from bone
- Interobservor variation