Imaging and Management of Blunt Cerebrovascular Injury

Abstract

Blunt cerebrovascular injury (BCVI) is a relatively rare but potentially devastating finding in patients with high-energy blunt force trauma or direct cervical and/or craniofacial injury. The radiologist plays an essential role in identifying and grading the various types of vascular injury, including minimal intimal injury, dissection with raised intimal flap or intraluminal thrombus, intramural hematoma, pseudoaneurysm, occlusion, transection, and arteriovenous fistula. Early identification of BCVI is important, as treatment with antithrombotic therapy has been shown to reduce the incidence of postinjury ischemic stroke. Patients with specific mechanisms of injury, particular imaging findings, or certain clinical signs and symptoms have been identified as appropriate and cost-effective for BCVI screening. Although digital subtraction angiography was previously considered the standard examination for screening, technologic improvements have led to its replacement with computed tomographic angiography. Of note, although not appropriate for screening, improvements in magnetic resonance angiography with vessel wall imaging hold promise as supplemental imaging studies that may improve diagnostic specificity for vessel wall injuries. Understanding the screening criteria, imaging modalities of choice, imaging appearances, and grading of BCVI is essential for the radiologist to ensure fast and appropriate diagnosis and treatment. This article details the imaging evaluation of BCVI and discusses the clinical and follow-up imaging implications of specific injury findings. ^©RSNA, 2018.

Figure 1.

Cerebrovascular injury from trivial trauma in a 35-year-old man who presented with left posterior cerebral artery territory stroke after chiropractic manipulation. Axial CT angiogram shows bilateral vertebral artery dissections, with right vertebral artery intramural hematoma narrowing the lumen (arrowheads), as well as left vertebral artery dissection and intraluminal thrombus (arrow). An abrupt cutoff in the left posterior cerebral artery was also seen (not shown), representing a thromboembolic occlusion.

Figure 2a.

(a) Longitudinal stretching and/or twisting of the vessel. Illustration depicts hyperextension and contralateral rotation, with stretching of the ICA over the C1–C3 transverse processes (red dashed arrows). Blue arrows in a–c = direction of movement. (b) Vessel impingement. Illustration depicts compression of the ICA between the mandible and spine (yellow arrows), which may result from hyperflexion or displaced mandible fracture. Impingement may also result from skull base or cervical spine fracture. Likewise, a blow to the neck or strangulation may directly compress or impinge a vessel against an adjacent structure. (c) Stretching of the vessel. Illustration depicts stretching of the vertebral artery between subluxated or dislocated bone structures (red dashed arrows), which may occur in cases of cervical fracture, dislocation, or ligamentous injury. (d) Direct laceration. Illustration depicts a fracture with direct injury to the vertebral artery by an adjacent bone fragment (orange arrows). This is especially relevant in cases of vertebral transverse foramen or carotid canal fracture.

Figure 2b.

(a) Longitudinal stretching and/or twisting of the vessel. Illustration depicts hyperextension and contralateral rotation, with stretching of the ICA over the C1–C3 transverse processes (red dashed arrows). Blue arrows in a–c = direction of movement. (b) Vessel impingement. Illustration depicts compression of the ICA between the mandible and spine (yellow arrows), which may result from hyperflexion or displaced mandible fracture. Impingement may also result from skull base or cervical spine fracture. Likewise, a blow to the neck or strangulation may directly compress or impinge a vessel against an adjacent structure. (c) Stretching of the vessel. Illustration depicts stretching of the vertebral artery between subluxated or dislocated bone structures (red dashed arrows), which may occur in cases of cervical fracture, dislocation, or ligamentous injury. (d) Direct laceration. Illustration depicts a fracture with direct injury to the vertebral artery by an adjacent bone fragment (orange arrows). This is especially relevant in cases of vertebral transverse foramen or carotid canal fracture.

Figure 2c.

(a) Longitudinal stretching and/or twisting of the vessel. Illustration depicts hyperextension and contralateral rotation, with stretching of the ICA over the C1–C3 transverse processes (red dashed arrows). Blue arrows in a–c = direction of movement. (b) Vessel impingement. Illustration depicts compression of the ICA between the mandible and spine (yellow arrows), which may result from hyperflexion or displaced mandible fracture. Impingement may also result from skull base or cervical spine fracture. Likewise, a blow to the neck or strangulation may directly compress or impinge a vessel against an adjacent structure. (c) Stretching of the vessel. Illustration depicts stretching of the vertebral artery between subluxated or dislocated bone structures (red dashed arrows), which may occur in cases of cervical fracture, dislocation, or ligamentous injury. (d) Direct laceration. Illustration depicts a fracture with direct injury to the vertebral artery by an adjacent bone fragment (orange arrows). This is especially relevant in cases of vertebral transverse foramen or carotid canal fracture.

Figure 2d.

(a) Longitudinal stretching and/or twisting of the vessel. Illustration depicts hyperextension and contralateral rotation, with stretching of the ICA over the C1–C3 transverse processes (red dashed arrows). Blue arrows in a–c = direction of movement. (b) Vessel impingement. Illustration depicts compression of the ICA between the mandible and spine (yellow arrows), which may result from hyperflexion or displaced mandible fracture. Impingement may also result from skull base or cervical spine fracture. Likewise, a blow to the neck or strangulation may directly compress or impinge a vessel against an adjacent structure. (c) Stretching of the vessel. Illustration depicts stretching of the vertebral artery between subluxated or dislocated bone structures (red dashed arrows), which may occur in cases of cervical fracture, dislocation, or ligamentous injury. (d) Direct laceration. Illustration depicts a fracture with direct injury to the vertebral artery by an adjacent bone fragment (orange arrows). This is especially relevant in cases of vertebral transverse foramen or carotid canal fracture.

Figure 3a.

Blunt arterial injury pathophysiology. Blue arrows = injury progression. (a) Illustration depicts an intimal injury with dissection. An intimal tear may dissect, progress cranially, and cause luminal narrowing or occlusion. Thrombus may form in the false lumen and at the site of injury, leading to embolization and downstream occlusion. Black arrows = direction of blood flow. (b) Illustration depicts an intramural hematoma, an adventitiomedial injury, in which the intima may remain intact. An intramural hematoma forms within the vessel wall due to bleeding from the vasa vasorum. Blood can then dissect through the media and/or adventitia, causing luminal stenosis and/or occlusion.

Figure 3b.

Blunt arterial injury pathophysiology. Blue arrows = injury progression. (a) Illustration depicts an intimal injury with dissection. An intimal tear may dissect, progress cranially, and cause luminal narrowing or occlusion. Thrombus may form in the false lumen and at the site of injury, leading to embolization and downstream occlusion. Black arrows = direction of blood flow. (b) Illustration depicts an intramural hematoma, an adventitiomedial injury, in which the intima may remain intact. An intramural hematoma forms within the vessel wall due to bleeding from the vasa vasorum. Blood can then dissect through the media and/or adventitia, causing luminal stenosis and/or occlusion.

Figure 4a.

BCVI in a young patient who underwent strangulation. (a, b) Axial (a) and sagittal (b) CT angiographic images show focal irregularity of the right ICA with wall thickening, causing mild narrowing (arrows), proximal to the skull base. DSA was performed to further define the injury. (c) Digital subtraction angiographic image shows a focal filling defect (arrow) at the site of injury, compatible with intraluminal thrombus versus intramural hematoma.

Figure 4b.

BCVI in a young patient who underwent strangulation. (a, b) Axial (a) and sagittal (b) CT angiographic images show focal irregularity of the right ICA with wall thickening, causing mild narrowing (arrows), proximal to the skull base. DSA was performed to further define the injury. (c) Digital subtraction angiographic image shows a focal filling defect (arrow) at the site of injury, compatible with intraluminal thrombus versus intramural hematoma.

Figure 4c.

BCVI in a young patient who underwent strangulation. (a, b) Axial (a) and sagittal (b) CT angiographic images show focal irregularity of the right ICA with wall thickening, causing mild narrowing (arrows), proximal to the skull base. DSA was performed to further define the injury. (c) Digital subtraction angiographic image shows a focal filling defect (arrow) at the site of injury, compatible with intraluminal thrombus versus intramural hematoma.

Figure 5a.

ICA dissection. (a) Axial fat-saturated T1-weighted MR image shows a hyperintense crescent (arrow) about the right ICA flow void, representing the false lumen. (b) Surface-rendered three-dimensional (3D) reconstruction of DSA data following right ICA injection shows irregularity and narrowing of the distal cervical right ICA (arrows).

Figure 5b.

ICA dissection. (a) Axial fat-saturated T1-weighted MR image shows a hyperintense crescent (arrow) about the right ICA flow void, representing the false lumen. (b) Surface-rendered three-dimensional (3D) reconstruction of DSA data following right ICA injection shows irregularity and narrowing of the distal cervical right ICA (arrows).

Figure 6a.

BCVI grading scale. (a) Illustration depicts a grade I injury, characterized by minimal intimal injury with vessel wall irregularity, dissection, or intramural hematoma, with less than 25% luminal stenosis. (b–d) Illustrations depict grade II injuries with intraluminal thrombus (b), dissection with a raised/displaced intimal flap (c), and intramural hematoma (d), with greater than 25% stenosis. (e) Illustration depicts a grade III injury pseudoaneurysm, seen as a focal outpouching/dilatation through a disrupted vessel wall. (f) Illustration depicts a grade IV injury, with dissection or thrombus causing vessel occlusion. (g) Illustration depicts a grade V injury, with complete vessel transection and extravasation.

Figure 6b.

BCVI grading scale. (a) Illustration depicts a grade I injury, characterized by minimal intimal injury with vessel wall irregularity, dissection, or intramural hematoma, with less than 25% luminal stenosis. (b–d) Illustrations depict grade II injuries with intraluminal thrombus (b), dissection with a raised/displaced intimal flap (c), and intramural hematoma (d), with greater than 25% stenosis. (e) Illustration depicts a grade III injury pseudoaneurysm, seen as a focal outpouching/dilatation through a disrupted vessel wall. (f) Illustration depicts a grade IV injury, with dissection or thrombus causing vessel occlusion. (g) Illustration depicts a grade V injury, with complete vessel transection and extravasation.

Figure 6c.

BCVI grading scale. (a) Illustration depicts a grade I injury, characterized by minimal intimal injury with vessel wall irregularity, dissection, or intramural hematoma, with less than 25% luminal stenosis. (b–d) Illustrations depict grade II injuries with intraluminal thrombus (b), dissection with a raised/displaced intimal flap (c), and intramural hematoma (d), with greater than 25% stenosis. (e) Illustration depicts a grade III injury pseudoaneurysm, seen as a focal outpouching/dilatation through a disrupted vessel wall. (f) Illustration depicts a grade IV injury, with dissection or thrombus causing vessel occlusion. (g) Illustration depicts a grade V injury, with complete vessel transection and extravasation.

Figure 6d.

BCVI grading scale. (a) Illustration depicts a grade I injury, characterized by minimal intimal injury with vessel wall irregularity, dissection, or intramural hematoma, with less than 25% luminal stenosis. (b–d) Illustrations depict grade II injuries with intraluminal thrombus (b), dissection with a raised/displaced intimal flap (c), and intramural hematoma (d), with greater than 25% stenosis. (e) Illustration depicts a grade III injury pseudoaneurysm, seen as a focal outpouching/dilatation through a disrupted vessel wall. (f) Illustration depicts a grade IV injury, with dissection or thrombus causing vessel occlusion. (g) Illustration depicts a grade V injury, with complete vessel transection and extravasation.

Figure 6e.

BCVI grading scale. (a) Illustration depicts a grade I injury, characterized by minimal intimal injury with vessel wall irregularity, dissection, or intramural hematoma, with less than 25% luminal stenosis. (b–d) Illustrations depict grade II injuries with intraluminal thrombus (b), dissection with a raised/displaced intimal flap (c), and intramural hematoma (d), with greater than 25% stenosis. (e) Illustration depicts a grade III injury pseudoaneurysm, seen as a focal outpouching/dilatation through a disrupted vessel wall. (f) Illustration depicts a grade IV injury, with dissection or thrombus causing vessel occlusion. (g) Illustration depicts a grade V injury, with complete vessel transection and extravasation.

Figure 6f.

BCVI grading scale. (a) Illustration depicts a grade I injury, characterized by minimal intimal injury with vessel wall irregularity, dissection, or intramural hematoma, with less than 25% luminal stenosis. (b–d) Illustrations depict grade II injuries with intraluminal thrombus (b), dissection with a raised/displaced intimal flap (c), and intramural hematoma (d), with greater than 25% stenosis. (e) Illustration depicts a grade III injury pseudoaneurysm, seen as a focal outpouching/dilatation through a disrupted vessel wall. (f) Illustration depicts a grade IV injury, with dissection or thrombus causing vessel occlusion. (g) Illustration depicts a grade V injury, with complete vessel transection and extravasation.

Figure 6g.

BCVI grading scale. (a) Illustration depicts a grade I injury, characterized by minimal intimal injury with vessel wall irregularity, dissection, or intramural hematoma, with less than 25% luminal stenosis. (b–d) Illustrations depict grade II injuries with intraluminal thrombus (b), dissection with a raised/displaced intimal flap (c), and intramural hematoma (d), with greater than 25% stenosis. (e) Illustration depicts a grade III injury pseudoaneurysm, seen as a focal outpouching/dilatation through a disrupted vessel wall. (f) Illustration depicts a grade IV injury, with dissection or thrombus causing vessel occlusion. (g) Illustration depicts a grade V injury, with complete vessel transection and extravasation.

Figure 7.

Minimal intimal injury in a trauma patient with multiple calvarial and facial fractures. Oblique maximum intensity projection (MIP) CT angiogram demonstrates mild wall thickening and irregularity with less than 25% luminal narrowing (arrows), compatible with a grade I injury.

Figure 8a.

Minimal intimal injury in a trauma patient. (a) Coronal CT angiogram shows what appears to be minimal luminal irregularity (arrows), compatible with a grade I injury. (b, c) Axial (b) and coronal (c) fat-saturated T1-weighted MR images show normal signal intensity in the vessel walls (arrows). Lack of intramural hematoma or wall thickening suggests that the CT angiographic findings (a) likely represent artifact or chronic irregularity.

Figure 8b.

Minimal intimal injury in a trauma patient. (a) Coronal CT angiogram shows what appears to be minimal luminal irregularity (arrows), compatible with a grade I injury. (b, c) Axial (b) and coronal (c) fat-saturated T1-weighted MR images show normal signal intensity in the vessel walls (arrows). Lack of intramural hematoma or wall thickening suggests that the CT angiographic findings (a) likely represent artifact or chronic irregularity.

Figure 8c.

Minimal intimal injury in a trauma patient. (a) Coronal CT angiogram shows what appears to be minimal luminal irregularity (arrows), compatible with a grade I injury. (b, c) Axial (b) and coronal (c) fat-saturated T1-weighted MR images show normal signal intensity in the vessel walls (arrows). Lack of intramural hematoma or wall thickening suggests that the CT angiographic findings (a) likely represent artifact or chronic irregularity.

Figures 9.

Intramural hematoma in a polytrauma patient with skull fractures after a motor vehicle collision. Axial CT angiogram shows luminal irregularity with greater than 25% narrowing of the petrous/lacerum segment of the left ICA (arrows), compatible with a grade II injury. No definite displaced intimal flap or false lumen was noted. The findings likely represent intramural hematoma.

Figures 10a.

Intramural hematoma and intraluminal thrombus. Axial (a) and sagittal (b) CT angiographic images at the C1 level demonstrate left V3 segment vertebral artery wall thickening and luminal narrowing (>25%) (black arrows), representing intramural hematoma, as well as a focal luminal thrombus (white arrow in b), compatible with grade II injury.

Figures 10b.

Intramural hematoma and intraluminal thrombus. Axial (a) and sagittal (b) CT angiographic images at the C1 level demonstrate left V3 segment vertebral artery wall thickening and luminal narrowing (>25%) (black arrows), representing intramural hematoma, as well as a focal luminal thrombus (white arrow in b), compatible with grade II injury.

Figure 11a.

Displaced intimal flap of the common carotid artery in a 30-year-old man who presented with Le Fort II fractures after being hit in the face with a boulder. Axial (a) and coronal MIP (b) CT angiographic images show a displaced intimal flap of the right common carotid artery (arrow), compatible with grade II injury. Of note, BCVI is relatively rare in the common carotid arteries compared with the internal carotid and vertebral arteries.

Figure 11b.

Displaced intimal flap of the common carotid artery in a 30-year-old man who presented with Le Fort II fractures after being hit in the face with a boulder. Axial (a) and coronal MIP (b) CT angiographic images show a displaced intimal flap of the right common carotid artery (arrow), compatible with grade II injury. Of note, BCVI is relatively rare in the common carotid arteries compared with the internal carotid and vertebral arteries.

Figure 12a.

Dissection with raised intimal flap in a patient with Le Fort III facial fractures and fracture of a cervical transverse foramen (black arrow in a) after a motorcycle collision. Axial (a) and sagittal (b) CT angiographic images demonstrate a mural thrombus with raised intimal flap of the left vertebral artery within the transverse foramen (white arrow), adjacent to the fracture.

Figure 12b.

Dissection with raised intimal flap in a patient with Le Fort III facial fractures and fracture of a cervical transverse foramen (black arrow in a) after a motorcycle collision. Axial (a) and sagittal (b) CT angiographic images demonstrate a mural thrombus with raised intimal flap of the left vertebral artery within the transverse foramen (white arrow), adjacent to the fracture.

Figure 13a.

Focal intramural/intraluminal thrombus in a patient with cervical spine fractures after a high-speed motor vehicle collision. Axial (a) and sagittal (b) CT angiographic images show a mural thrombus (arrow) with focal narrowing greater than 25%, a grade II injury.

Figure 13b.

Focal intramural/intraluminal thrombus in a patient with cervical spine fractures after a high-speed motor vehicle collision. Axial (a) and sagittal (b) CT angiographic images show a mural thrombus (arrow) with focal narrowing greater than 25%, a grade II injury.

Figure 14a.

Pseudoaneurysm in a patient with minimal trauma but who had a family history of dissections. Axial (a) and sagittal (b) MIP CT angiographic images and lateral neck digital subtraction angiographic image following a left common carotid artery injection (c) show a large saccular outpouching of contrast material from the left ICA (arrow), representing a pseudoaneurysm and compatible with grade III injury.

Figure 14b.

Pseudoaneurysm in a patient with minimal trauma but who had a family history of dissections. Axial (a) and sagittal (b) MIP CT angiographic images and lateral neck digital subtraction angiographic image following a left common carotid artery injection (c) show a large saccular outpouching of contrast material from the left ICA (arrow), representing a pseudoaneurysm and compatible with grade III injury.

Figure 14c.

Pseudoaneurysm in a patient with minimal trauma but who had a family history of dissections. Axial (a) and sagittal (b) MIP CT angiographic images and lateral neck digital subtraction angiographic image following a left common carotid artery injection (c) show a large saccular outpouching of contrast material from the left ICA (arrow), representing a pseudoaneurysm and compatible with grade III injury.

Figure 15a.

Pseudoaneurysm with enlargement at follow-up imaging in a polytrauma patient with cervical spine fractures. (a) Sagittal oblique MIP CT angiogram shows a pseudoaneurysm of the right cervical ICA (arrow), representing a grade III injury. The pseudoaneurysm and associated mural hematoma narrow the adjacent lumen (arrowhead). (b) Sagittal oblique CT angiogram obtained 7 days later shows slight interval enlargement of the pseudoaneurysm (arrow).

Figure 15b.

Pseudoaneurysm with enlargement at follow-up imaging in a polytrauma patient with cervical spine fractures. (a) Sagittal oblique MIP CT angiogram shows a pseudoaneurysm of the right cervical ICA (arrow), representing a grade III injury. The pseudoaneurysm and associated mural hematoma narrow the adjacent lumen (arrowhead). (b) Sagittal oblique CT angiogram obtained 7 days later shows slight interval enlargement of the pseudoaneurysm (arrow).

Figure 16a.

ICA occlusion in a patient who presented with polytrauma, including bilateral skull base fractures, after being struck by a motor vehicle. Coronal CT angiogram (a) and oblique digital subtraction angiographic image obtained after a right common carotid artery injection (b) show dissection with tapering and complete occlusion of the proximal cervical ICA (arrow), representing a grade IV injury.

Figure 16b.

ICA occlusion in a patient who presented with polytrauma, including bilateral skull base fractures, after being struck by a motor vehicle. Coronal CT angiogram (a) and oblique digital subtraction angiographic image obtained after a right common carotid artery injection (b) show dissection with tapering and complete occlusion of the proximal cervical ICA (arrow), representing a grade IV injury.

Figure 17a.

Vertebral artery occlusion. (a, b) Sagittal oblique (a) and sagittal (b) CT angiographic images show occlusion of the proximal right vertebral artery (arrow in a), with reconstitution distally at the C3–C4 vertebral level (white arrow in b), compatible with a grade IV injury. Fracture of the C5 articular facet (black arrow in b) is also seen. (c, d) Axial CT angiographic (c) and axial T2-weighted MR (d) images demonstrate occlusion (arrow in c) and loss of right vertebral artery flow void (arrowhead in d).

Figure 17b.

Vertebral artery occlusion. (a, b) Sagittal oblique (a) and sagittal (b) CT angiographic images show occlusion of the proximal right vertebral artery (arrow in a), with reconstitution distally at the C3–C4 vertebral level (white arrow in b), compatible with a grade IV injury. Fracture of the C5 articular facet (black arrow in b) is also seen. (c, d) Axial CT angiographic (c) and axial T2-weighted MR (d) images demonstrate occlusion (arrow in c) and loss of right vertebral artery flow void (arrowhead in d).

Figure 17c.

Vertebral artery occlusion. (a, b) Sagittal oblique (a) and sagittal (b) CT angiographic images show occlusion of the proximal right vertebral artery (arrow in a), with reconstitution distally at the C3–C4 vertebral level (white arrow in b), compatible with a grade IV injury. Fracture of the C5 articular facet (black arrow in b) is also seen. (c, d) Axial CT angiographic (c) and axial T2-weighted MR (d) images demonstrate occlusion (arrow in c) and loss of right vertebral artery flow void (arrowhead in d).

Figure 17d.

Vertebral artery occlusion. (a, b) Sagittal oblique (a) and sagittal (b) CT angiographic images show occlusion of the proximal right vertebral artery (arrow in a), with reconstitution distally at the C3–C4 vertebral level (white arrow in b), compatible with a grade IV injury. Fracture of the C5 articular facet (black arrow in b) is also seen. (c, d) Axial CT angiographic (c) and axial T2-weighted MR (d) images demonstrate occlusion (arrow in c) and loss of right vertebral artery flow void (arrowhead in d).

Figure 18a.

Vertebral artery transection in a polytrauma patient with atlanto-occipital dissociation. (a) Axial CT image shows active extravasation of contrast material within a large hematoma at the widened craniocervical junction (arrows). (b, c) Axial (b) and coronal (c) MIP images from CT angiography demonstrate hemorrhage from the transected left V3–V4 segment vertebral artery at the C1 level (arrows), representing grade V injury.

Figure 18b.

Vertebral artery transection in a polytrauma patient with atlanto-occipital dissociation. (a) Axial CT image shows active extravasation of contrast material within a large hematoma at the widened craniocervical junction (arrows). (b, c) Axial (b) and coronal (c) MIP images from CT angiography demonstrate hemorrhage from the transected left V3–V4 segment vertebral artery at the C1 level (arrows), representing grade V injury.

Figure 18c.

Vertebral artery transection in a polytrauma patient with atlanto-occipital dissociation. (a) Axial CT image shows active extravasation of contrast material within a large hematoma at the widened craniocervical junction (arrows). (b, c) Axial (b) and coronal (c) MIP images from CT angiography demonstrate hemorrhage from the transected left V3–V4 segment vertebral artery at the C1 level (arrows), representing grade V injury.

Figure 19a.

Vertebral artery transection and AVF in a polytrauma patient with C4–C5 fracture dislocation. (a) Coronal MIP image from CT angiography shows active extravasation with a hematoma (arrow) centered in the right C4 transverse foramen at the level of the fracture-dislocation. (b) Right vertebral artery injection catheter angiogram shows active extravasation, representing transection of the right vertebral artery (arrow), compatible with grade V injury. (c) Left vertebral artery angiogram shows retrograde flow into the right vertebral artery, to the level of the transection (arrow). (d–f) Right vertebral artery injection digital subtraction angiographic images in three subsequent phases show early venous drainage, compatible with AVF.

Figure 19b.

Vertebral artery transection and AVF in a polytrauma patient with C4–C5 fracture dislocation. (a) Coronal MIP image from CT angiography shows active extravasation with a hematoma (arrow) centered in the right C4 transverse foramen at the level of the fracture-dislocation. (b) Right vertebral artery injection catheter angiogram shows active extravasation, representing transection of the right vertebral artery (arrow), compatible with grade V injury. (c) Left vertebral artery angiogram shows retrograde flow into the right vertebral artery, to the level of the transection (arrow). (d–f) Right vertebral artery injection digital subtraction angiographic images in three subsequent phases show early venous drainage, compatible with AVF.

Figure 19c.

Vertebral artery transection and AVF in a polytrauma patient with C4–C5 fracture dislocation. (a) Coronal MIP image from CT angiography shows active extravasation with a hematoma (arrow) centered in the right C4 transverse foramen at the level of the fracture-dislocation. (b) Right vertebral artery injection catheter angiogram shows active extravasation, representing transection of the right vertebral artery (arrow), compatible with grade V injury. (c) Left vertebral artery angiogram shows retrograde flow into the right vertebral artery, to the level of the transection (arrow). (d–f) Right vertebral artery injection digital subtraction angiographic images in three subsequent phases show early venous drainage, compatible with AVF.

Figure 19d.

Vertebral artery transection and AVF in a polytrauma patient with C4–C5 fracture dislocation. (a) Coronal MIP image from CT angiography shows active extravasation with a hematoma (arrow) centered in the right C4 transverse foramen at the level of the fracture-dislocation. (b) Right vertebral artery injection catheter angiogram shows active extravasation, representing transection of the right vertebral artery (arrow), compatible with grade V injury. (c) Left vertebral artery angiogram shows retrograde flow into the right vertebral artery, to the level of the transection (arrow). (d–f) Right vertebral artery injection digital subtraction angiographic images in three subsequent phases show early venous drainage, compatible with AVF.

Figure 19e.

Vertebral artery transection and AVF in a polytrauma patient with C4–C5 fracture dislocation. (a) Coronal MIP image from CT angiography shows active extravasation with a hematoma (arrow) centered in the right C4 transverse foramen at the level of the fracture-dislocation. (b) Right vertebral artery injection catheter angiogram shows active extravasation, representing transection of the right vertebral artery (arrow), compatible with grade V injury. (c) Left vertebral artery angiogram shows retrograde flow into the right vertebral artery, to the level of the transection (arrow). (d–f) Right vertebral artery injection digital subtraction angiographic images in three subsequent phases show early venous drainage, compatible with AVF.

Figure 19f.

Vertebral artery transection and AVF in a polytrauma patient with C4–C5 fracture dislocation. (a) Coronal MIP image from CT angiography shows active extravasation with a hematoma (arrow) centered in the right C4 transverse foramen at the level of the fracture-dislocation. (b) Right vertebral artery injection catheter angiogram shows active extravasation, representing transection of the right vertebral artery (arrow), compatible with grade V injury. (c) Left vertebral artery angiogram shows retrograde flow into the right vertebral artery, to the level of the transection (arrow). (d–f) Right vertebral artery injection digital subtraction angiographic images in three subsequent phases show early venous drainage, compatible with AVF.

Figure 20a.

Atherosclerosis mimicking BCVI in a polytrauma patient at high risk for BCVI. (a) Coronal MIP image from CT angiography shows a mural lesion causing narrowing of the proximal left vertebral artery (arrow). Associated calcification is present, compatible with atherosclerotic plaque. (b) Axial CT angiographic image at the C1 level shows a calcified atherosclerotic plaque of the right V3 vertebral artery, causing narrowing and wall thickening (arrow), mimicking a stenotic BCVI (ie, intramural hematoma).

Figure 20b.

Atherosclerosis mimicking BCVI in a polytrauma patient at high risk for BCVI. (a) Coronal MIP image from CT angiography shows a mural lesion causing narrowing of the proximal left vertebral artery (arrow). Associated calcification is present, compatible with atherosclerotic plaque. (b) Axial CT angiographic image at the C1 level shows a calcified atherosclerotic plaque of the right V3 vertebral artery, causing narrowing and wall thickening (arrow), mimicking a stenotic BCVI (ie, intramural hematoma).

Figure 21a.

BCVI involving coiled or looped vascular segments. Coiled or looped vascular segments make evaluation for luminal and wall abnormalities difficult. Axial (a) and coronal (b) MIP images from CT angiography show a small medially directed pseudoaneurysm (arrow), which is easily ignored as it subtly projects from the coiled segment.

Figure 21b.

BCVI involving coiled or looped vascular segments. Coiled or looped vascular segments make evaluation for luminal and wall abnormalities difficult. Axial (a) and coronal (b) MIP images from CT angiography show a small medially directed pseudoaneurysm (arrow), which is easily ignored as it subtly projects from the coiled segment.

Figure 22.

Streak artifact. Axial CT angiogram shows extensive streak artifact emanating from the dental amalgam, which makes the evaluation of arterial contours difficult. A grade II BCVI of the right vertebral artery (arrow) is difficult to appreciate. Additionally, one may imagine the presence of linear filling defects in the normal bilateral ICAs (arrowheads); the artifactual streaks mimic subtle dissection flaps.

Figure 23a.

Definitive treatment of a large pseudoaneurysm. (a) Lateral projection angiogram of the left common carotid artery shows a large left cervical ICA aneurysm (arrow). (b) Postoperative frontal projection angiogram of the left common carotid artery shows the patent proximal ICA–to–middle cerebral artery bypass graft (arrow).

Figure 23b.

Definitive treatment of a large pseudoaneurysm. (a) Lateral projection angiogram of the left common carotid artery shows a large left cervical ICA aneurysm (arrow). (b) Postoperative frontal projection angiogram of the left common carotid artery shows the patent proximal ICA–to–middle cerebral artery bypass graft (arrow).

Figure 24a.

Healing of a low-grade injury in a polytrauma patient. (a) Oblique sagittal MIP image from CT angiography shows a focal intramural hematoma in the right cervical ICA (arrow) causing 25%–50% narrowing, representing a grade II injury. (b) Oblique sagittal MIP image from follow-up CT angiography obtained after 3 months of antiplatelet therapy demonstrates near-complete healing of the grade II injury in the cervical ICA (arrow).

Figure 24b.

Healing of a low-grade injury in a polytrauma patient. (a) Oblique sagittal MIP image from CT angiography shows a focal intramural hematoma in the right cervical ICA (arrow) causing 25%–50% narrowing, representing a grade II injury. (b) Oblique sagittal MIP image from follow-up CT angiography obtained after 3 months of antiplatelet therapy demonstrates near-complete healing of the grade II injury in the cervical ICA (arrow).

Figure 25a.

Worsening of a low-grade injury in a polytrauma patient with right occipital condyle fracture. (a) Oblique CT angiogram of the right vertebral artery at the time of injury shows an intramural hematoma (arrow) with 25%–50% narrowing, representing grade I–II injury. (b, c) Oblique (b) and frontal projection 3D-rendered (c) images from CT angiography obtained 7 days later show development of a small pseudoaneurysm (arrow), which represents progression to a grade III injury.

Figure 25b.

Worsening of a low-grade injury in a polytrauma patient with right occipital condyle fracture. (a) Oblique CT angiogram of the right vertebral artery at the time of injury shows an intramural hematoma (arrow) with 25%–50% narrowing, representing grade I–II injury. (b, c) Oblique (b) and frontal projection 3D-rendered (c) images from CT angiography obtained 7 days later show development of a small pseudoaneurysm (arrow), which represents progression to a grade III injury.

Figure 25c.

Worsening of a low-grade injury in a polytrauma patient with right occipital condyle fracture. (a) Oblique CT angiogram of the right vertebral artery at the time of injury shows an intramural hematoma (arrow) with 25%–50% narrowing, representing grade I–II injury. (b, c) Oblique (b) and frontal projection 3D-rendered (c) images from CT angiography obtained 7 days later show development of a small pseudoaneurysm (arrow), which represents progression to a grade III injury.

Figure 26a.

Vessel wall imaging of left ICA dissection. (a, b) Axial (a) and oblique (b) images from initial CT angiography show a high-grade stenosis, with a thin string of contrast material opacification (arrow), proximal to the skull base. Vessel wall MR imaging was performed 5 weeks later. (c) Three-dimensional time-of-flight MIP image shows improvement of the stenosis, with only minimal remaining luminal narrowing (arrow). (d, e) Axial (d) and coronal (e) black-blood fat-saturated T1-weighted MR images show persistent hyperintensity (arrowheads) within a thickened arterial wall, compatible with a subacute intramural hematoma. Note that, unlike the luminal time-of-flight MR angiogram, the vessel wall MR imaging sequences delineate the extent of true vessel wall disease.

Figure 26b.

Vessel wall imaging of left ICA dissection. (a, b) Axial (a) and oblique (b) images from initial CT angiography show a high-grade stenosis, with a thin string of contrast material opacification (arrow), proximal to the skull base. Vessel wall MR imaging was performed 5 weeks later. (c) Three-dimensional time-of-flight MIP image shows improvement of the stenosis, with only minimal remaining luminal narrowing (arrow). (d, e) Axial (d) and coronal (e) black-blood fat-saturated T1-weighted MR images show persistent hyperintensity (arrowheads) within a thickened arterial wall, compatible with a subacute intramural hematoma. Note that, unlike the luminal time-of-flight MR angiogram, the vessel wall MR imaging sequences delineate the extent of true vessel wall disease.

Figure 26c.

Vessel wall imaging of left ICA dissection. (a, b) Axial (a) and oblique (b) images from initial CT angiography show a high-grade stenosis, with a thin string of contrast material opacification (arrow), proximal to the skull base. Vessel wall MR imaging was performed 5 weeks later. (c) Three-dimensional time-of-flight MIP image shows improvement of the stenosis, with only minimal remaining luminal narrowing (arrow). (d, e) Axial (d) and coronal (e) black-blood fat-saturated T1-weighted MR images show persistent hyperintensity (arrowheads) within a thickened arterial wall, compatible with a subacute intramural hematoma. Note that, unlike the luminal time-of-flight MR angiogram, the vessel wall MR imaging sequences delineate the extent of true vessel wall disease.

Figure 26d.

Vessel wall imaging of left ICA dissection. (a, b) Axial (a) and oblique (b) images from initial CT angiography show a high-grade stenosis, with a thin string of contrast material opacification (arrow), proximal to the skull base. Vessel wall MR imaging was performed 5 weeks later. (c) Three-dimensional time-of-flight MIP image shows improvement of the stenosis, with only minimal remaining luminal narrowing (arrow). (d, e) Axial (d) and coronal (e) black-blood fat-saturated T1-weighted MR images show persistent hyperintensity (arrowheads) within a thickened arterial wall, compatible with a subacute intramural hematoma. Note that, unlike the luminal time-of-flight MR angiogram, the vessel wall MR imaging sequences delineate the extent of true vessel wall disease.

Figure 26e.

Vessel wall imaging of left ICA dissection. (a, b) Axial (a) and oblique (b) images from initial CT angiography show a high-grade stenosis, with a thin string of contrast material opacification (arrow), proximal to the skull base. Vessel wall MR imaging was performed 5 weeks later. (c) Three-dimensional time-of-flight MIP image shows improvement of the stenosis, with only minimal remaining luminal narrowing (arrow). (d, e) Axial (d) and coronal (e) black-blood fat-saturated T1-weighted MR images show persistent hyperintensity (arrowheads) within a thickened arterial wall, compatible with a subacute intramural hematoma. Note that, unlike the luminal time-of-flight MR angiogram, the vessel wall MR imaging sequences delineate the extent of true vessel wall disease.