Imaging Pearls ❯ Vascular ❯ Neurovascular
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- “There are multiple suggested causes for the left-sided predominance of venous reflux. Anatomic differences in the course of the brachiocephalic veins may be a factor. The right brachiocephalic vein is more parallel to the ascending aorta, whereas the course of the left crosses the aorta and is, therefore, more susceptible to anatomic compression. An aberrant right subclavian artery may compress the left brachiocephalic vein. Hypertension or age-related ectasia and tortuosity of the aorta may also compress the left brachiocephalic vein. In addition, retrosternal narrowing can also predispose to jugular venous reflux with left-sided injections.”
Computed Tomography Angiography of the Neurovascular Circulation Mohan S et al. Radiol Clin N Am 54 (2016) 147–162 - “The preferred site of injection is the
right antecubital vein that minimizes artifacts from dense contrast in the left brachiocephalic vein. Artifacts related to left-sided venous injection include artifact from dense contrast in the brachiocephalic vein obscuring adjacent arteries, reflux of contrast into the jugular veins simulating filling defects, and simple reflux into the internal jugular vein and/or vertebral veins or vertebral venous plexus reaching the dural venous sinuses and possible retrograde brain parenchymal enhancement.”
Computed Tomography Angiography of the Neurovascular Circulation Mohan S et al. Radiol Clin N Am 54 (2016) 147–162 - “CTA is a powerful and reliable tool to demonstrate the vasculature of the head and neck with proven utility for the detection and characterization of vascular diseases particularly in the acute setting. It may be used as the primary modality for detecting disease or as an adjunct tool for better characterizing known disease or assessing changes in the disease state over time. With the proliferation of CT scanners in the emergency departments, CTA examinations will continue to grow in numbers, helping to guide intervention in the emergency setting of neurovascular diseases.”
Computed Tomography Angiography of the Neurovascular Circulation Mohan S et al. Radiol Clin N Am 54 (2016) 147–162 - Common indications for neurovascular CTA
• Arterial and venous aneurysms or pseudoaneurysms
• Stroke and vasospasm
• Atherosclerotic occlusive disease
• Nonatherosclerotic, noninflammatory vasculopathy
• Traumatic injuries to arteries and veins
• Arterial dissection and intramural hematoma - Common indications for neurovascular CTA
• Venous and dural sinus thrombosis
• Congenital vascular anomalies
• Vascular anatomic variants
• Vascular interventions (percutaneous and surgical)
• Vasculitis and collagen vascular diseases
• Vascular infection
• Head and neck tumors of vascular origin, with rich vascular supply or invading vascular structures
• Computed Tomography Angiography of the Neurovascular Circulation Mohan S et al. Radiol Clin N Am 54 (2016) 147–162 - “Computed tomographic angiography (CTA) of the abdominal aorta has replaced angiography as the initial imaging test of choice for acute aortic disease, occlusive atherosclerotic disease, inflammatory vasculitis workups, and preintervention/ postintervention imaging of abdominal aortic aneurysms (AAA) at most centers.”
Computed Tomographic Angiography of the Abdominal Aorta Hansen NJ Radiol Clin N Am 54 (2016) 35–54
- “Originally thought to be a rare occurrence, blunt cerebrovascular injuries (BCVIs) are now diagnosed in approximately 1% of blunt trauma patients. Early imaging of patients has resulted in the diagnosis of BCVIs during the asymptomatic phase, thus allowing prompt treatment. Although the ideal regimen of antithrombotic therapy has yet to be determined, treatment with either antiplatelet agents or anticoagulation has been shown to markedly reduce BCVI-related stroke rate. BCVIs are rare, potentially devastating injuries; appropriate imaging in high-risk patients should be performed and prompt treatment initiated to prevent ischemic neurologic events.”
Imaging for blunt carotid and vertebral artery injuries
Burlew CC, Biffi WL
Surg Clin North Am 2011 Feb;91(1)217-31 - “The incidence of "indirect" cervical arterial injuries with craniofacial gunshot wounds is comparable to or slightly higher than those seen in pure blunt trauma. Screening patients with craniofacial gunshot injuries with CT angiography may yield unexpected cervical vascular injuries remote from the penetrating tract.”
Craniofacial gunshot injuries: an unrecognized risk factor for blunt cervical vascular injuries
Steenburg SD, Silker CE
Eur Radiol 2012 Sep;22(9):1837-43 - “Contrast material-enhanced helical computed tomographic (CT) angiography is increasingly being used to evaluate trauma patients in stable condition who are at risk for vascular injuries. It allows characterization of traumatic vascular lesions in the neck such as partial or complete occlusion, pseudoaneurysm, intimal flap, dissection, and arteriovenous fistula. In the same setting, CT angiography provides valuable additional information about the cervical soft tissues, aerodigestive tract, spinal canal, and spinal cord.”
Vascular injuries of the neck and thoracic inlet :helical CT-angiographic correlation
Nunez DB Jr et al.
Radiographics 2004. July-Aug 24(4);1087-98 - “CT angiography may be limited by artifacts from metallic fragments and occasionally by abundant soft-tissue air or streak artifacts in the shoulders. In such cases, conventional angiography is necessary for optimal assessment of vascular injuries. CT angiography can be used as a noninvasive alternative to conventional angiography in patients suspected to have vascular injuries but without initial indications for surgical treatment.”
Vascular injuries of the neck and thoracic inlet :helical CT-angiographic correlation
Nunez DB Jr et al.
Radiographics 2004. July-Aug 24(4);1087-98
"Radiologists should become familiar with the subtle signs of arterial injury and should have a low threshold for recommending catheter based angiography in equivocal cases as well as cases in which CTA quality is hindered by artifacts"
Imaging of traumatic arterial injuries in the neck with an emphasis on CTA
Schroeder JW et al
Emerg Radiol (2010) 17:109-122"Test characteristics for MR techniques such as MRI and MRA were relatively similar to those for CTA in diagnosis of carotid and vertebral artery dissection."
Comparison of Test Performance Characteristics of MRI, MR Angiography, and CT Angiography in the Diagnosis of Carotid and Vertebral Artery Dissection: A Review of the Medical Literature
Provenzale JM, Sarikaya B
AJR 2009; 193:1167-1174- "Helical CT Angiography can be used as the initial method for evaluation in patients with possible arterial injuries of the neck."
Penetrating Neck Injuries: Helical CT Angiography for Initial Evaluation
Munera F et al.
Radiology 2002; 224:366-372
- "Compared with the conventional volume score, multidetector row CT derived mineral mass is a less biased and more precise measurement of the mineral content of nonmoving ex vivo carotid endarterectomy specimens. Mineral mass and modified Agatson scores are more reproducible than conventional volume and Agatston scores."
Vascular Calcifications in ex Vivo Carotid Specimens: Precision and Accuracy with Multidetector Row CT
Hoffman U et al.
Radiology 2003; 229:375-381
- "Carotid siphon calcifications are strong predictors of existing medical disease."
Clinical Significance of Cavernous Carotid Calcifications Encountered on Head Computed Tomography Scans Performed on Patients Seen in the Emergency Department
Ptak T et al.
J Comput Assist Tomogr 27(4):505-509
- "Calcifications of the cavernous segment of the internal carotid artery are a consistent indicator of systemic disease."
Clinical Significance of Cavernous Carotid Calcifications Encountered on Head Computed Tomography Scans Performed on Patients Seen in the Emergency Department
Ptak T et al.
J Comput Assist Tomogr 27(4):505-509
- "Significant correlation exists between diabetes, hypercholesterolemia, and hypertension and the occurrence of carotid calcifications observed on screening head CT scans."
Clinical Significance of Cavernous Carotid Calcifications Encountered on Head Computed Tomography Scans Performed on Patients Seen in the Emergency Department
Ptak T et al.
J Comput Assist Tomogr 27(4):505-509