Cerebral vasospasm and hypoperfusion after traumatic brain injury: Combined CT angiography and CT perfusion imaging study

Abstract

Background: Timely identification of the cerebral perfusion abnormalities after traumatic brain injury (TBI) is highly important. The objective of this study was the evaluation of the post traumatic vasospasm and cerebral hypoperfusion with the serial combined CT angiography (CTA) and CT perfusion (CTP) imaging examinations.

Methods: The case series comprised 25 adult patients with closed TBI accompanied by various types of intracranial hematoma. Emergency surgery was done in 15 cases (60%). Combined CTA and CTP were performed on days 0 (D0) and 7 ± 1 (D7) after trauma.

Results: CTA on D0 did not demonstrate vasospasm in any case but revealed it on D7 in 9 patients (36%). In the multivariate analysis, only the presence of subarachnoid hemorrhage (SAH) on D7 had confirmed a significant association with the development of vasospasm (P = 0.0201). Cerebral hypoperfusion at least in one evaluated brain region was noted on D0 and D7 in 76% and 60% of patients, respectively, and showed highly variable spatial distribution and temporal development. Treatment results were not associated with the presence of vasospasm (P = 0.7337) or the number of brain regions affected by hypoperfusion on D0 (P = 0.2285), but the number of brain regions affected by hypoperfusion on D7 was significantly greater in cases of unfavorable outcome (P = 0.0187).

Conclusion: Vasospasm is merely related to SAH sustained at the subacute stage of TBI, but its spatial and temporary interrelationships with the post traumatic cerebral hypoperfusion are complex. Serial combined CTA and CTP examinations may facilitate monitoring of perfusion abnormalities and treatment guidance.

Keywords: CT angiography; CT perfusion imaging; Cerebral hypoperfusion; Post traumatic vasospasm; Traumatic brain injury.

Figure 1:

Neuroimaging findings in a 77-year-old woman with traumatic brain injury. Plain head CT at admission (a) revealed acute subdural hematoma above the right cerebral convexity causing brain shift, as well as multiple brain contusions, intracerebral hemorrhages, and subarachnoid hemorrhage, whereas CT angiography (CTA) (b) defined spot signs (arrows) within the anterior right temporal and posterior left temporal lobes. One hour later prominent expansion of the intracerebral hemorrhages was noted (c), thus urgent right-sided decompressive craniectomy and the evacuation of subdural hematoma were done. On the 8^th day after trauma and surgery, CTA (d and e) revealed localized vasospasm of the left M2 segment (arrows), whereas CT perfusion (f) showed marked hypoperfusion of the left frontal and temporal lobes (circle). Subsequent diffusion-weighted imaging (g and h) demonstrated multiple ischemic lesions (arrows) in both hemispheres.