Transcranial Doppler Ultrasound, Perfusion Computerized Tomography, and Cerebral Angiography Identify Different...

Area of Science:

• Neuroimaging
• Cerebrovascular Diseases
• Neurosurgery

Background:

• Controversy exists regarding the utility of transcranial Doppler (TCD) for predicting vasospasms in aneurysmal subarachnoid hemorrhage (aSAH).
• CT Perfusion (CTP) is a newer method for predicting delayed ischemic deficit (DCI), but its precise diagnostic target, including microcirculatory disturbances, is not fully understood.
• This study compares TCD and CTP findings against angiography and assesses their changes following intra-arterial spasmolytic therapy.

Purpose of the Study:

• To compare the diagnostic accuracy of TCD and CTP in detecting vasospasms in aSAH patients.
• To evaluate the effectiveness of intra-arterial spasmolytic therapy on TCD and CTP parameters.
• To determine if TCD and CTP identify distinct pathological entities contributing to DCI.

Main Methods:

• Retrospective analysis of TCD, CTP, and angiographic data from 77 aSAH patients (2013-2016).
• Comparison of TCD and CTP data before and after intra-arterial spasmolysis in 38 patients.
• Analysis of 39 patients with pathological CTP but no angiographically confirmed vasospasm.

Main Results:

• No significant correlation was found between established CTP mean transit time (MTT) thresholds and vasospasm, nor between TCD mean velocities and vasospasm.
• Following spasmolysis, only MTT showed significant improvement, while TCD velocities and Lindegaard index remained unchanged.
• A subset of patients (39) exhibited abnormal CTP findings without angiographically evident vasospasm.

Conclusions:

• TCD and CTP appear to detect different pathological mechanisms underlying DCI after aSAH.
• Supplementary use of both TCD and CTP is recommended for comprehensive identification of vasospasms.
• Combined imaging may improve the detection rate of vasospasms and subsequent DCI prediction in aSAH patients.