Whole Brain CT Perfusion Evaluation in Transient Ischaemic Attack: A Cross-sectional Study from a Tertiary Care Centre, New Delhi, India

Introduction: Few studies exist in current literature regarding imaging features in Transient Ischaemic Attack (TIA) and most of the previous studies on Computed Tomography Perfusion (CTP) have used old generation scanners with limited brain coverage.

Aim: To study the spectrum of whole brain CTP parameters in patients presenting with TIA using a 256 slice CT scanner.

Materials and Methods: This cross-sectional observational study was conducted on 15 patients, tertiary care centre in New Delhi, India over a period of 18 months from October 2017 till March 2019. All patients presenting with the first episode of TIA were evaluated with Non Contrast Computed Tomography (NCCT), Whole brain CTP, and Colour doppler of carotid vessels. Quantitative assessment and statistical analysis of the alteration of CT perfusion parameters was done in areas of visualised Focal Perfusion Abnormalities (FPA) and seven predefined locations in bilateral hemispheres on perfusion maps.

Results: Five out of 15 patients had FPAs in the colour maps and there was a significant elevation of Cerebral Blood Flow (CBF) and Cerebral Blood Volume (CBV) in the FPA region (p-value=0.018) suggestive of postischaemic hyperperfusion. The mean hemispheric CBF was increased in the abnormal hemisphere compared to the normal hemisphere (p-value=0.04).

Conclusion: CTP parameters are significantly altered in the patients with TIA with predominant increase in CBF and CBV in the patients who have FPA on CTP. CTP shows postischaemic hyperperfusion changes in the form of increased CBF in the hemisphere corresponding to the symptoms.