CT Perfusion in Acute Lacunar Stroke: Detection Capabilities Based on Infarct Location

Abstract

BACKGROUND AND PURPOSE: Recent studies demonstrated superiority of CTP to NCCT/CTA at detecting lacunar infarcts. This study aimed to assess CTP's capability to identify lacunae in different intracranial regions. MATERIALS AND METHODS: Over 5.5 years, 1085 CTP examinations were retrospectively reviewed in patients with acute stroke symptoms with CTP within 12 hours and MRI within 7 days of symptom onset. Patients had infarcts Յ2 cm or no acute infarct on DWI; patients with concomitant infarcts Ͼ2 cm on DWI were excluded. CTP postprocessing was automated by a delay-corrected algorithm. Three blinded reviewers were given patient NIHSS scores and symptoms; infarcts were recorded based on NCCT/CTA, CTP (CBF, CBV, MTT, and TTP), and DWI. RESULTS: One hundred thirteen patients met inclusion criteria (53.1% female). On DWI, lacunar infarcts were present in 37 of 113 (32.7%), and absent in 76 of 113 (67.3%). On CTP, lacunar infarcts typically appeared as abnormalities larger than infarct size on DWI. Interobserver for CTP ranged from 0.38 (CBF) (P Ͻ .0001) to 0.66 (TTP) (P Ͻ .0001); interobserver for DWI was 0.88 (P Ͻ 0.0001). In all intracranial regions, sensitivity of CTP ranged from 18.9% (CBV) to 48.7% (TTP); specificity ranged from 97.4% (CBF and TTP) to 98.7% (CBV and MTT). CTP's sensitivity was highest in the subcortical white matter with or without cortical involvement (21.7%-65.2%) followed by periventricular white matter (12.5%-37.5%); sensitivity in the thalami or basal ganglia was 0%. CONCLUSIONS: CTP has low sensitivity and high specificity in identifying lacunar infarcts. Sensitivity is highest in the subcortical white matter with or without cortical involvement, but limited in the basal ganglia and thalami.

Acute Reperfusion Therapies for Acute Ischemic Stroke

“…MR-based diffusion-weighted imaging (DWI) has also been utilized in the hyperacute stage of acute ischemic stroke management at select stroke centers. Some comparative studies have demonstrated superiority of MR-DWI protocols over CT perfusion maps for prediction of ischemic core [7], especially in cases of subcortical lesions [8][9][10], though its practical utility in the "real-world" setting remains relatively limited due to prolonged acquisition times compared to CT as well as 24/7 availability. In addition, MR perfusion protocols have been developed, which provide an alternative and arguably more reliable assessment of the penumbral tissue [7,11,12], especially in the later time windows, when compared to CT perfusion.…”

Cerebral perfusion and compensatory blood supply in patients with recent small subcortical infarcts

“…RSSIs can be observed as hypoperfused areas on computed tomography perfusion (CTP) maps despite their small volume. 7–12 The diagnostic yield of CTP in detecting RSSIs is conditioned by a high rate of false negative scans that have been explained by limited coverage, movements during image acquisition, bone artifacts, and low signal-to-noise ratio of the perfusion maps. 13 However, some RSSIs show no perfusion defects despite complete brain coverage and good quality of image acquisition, 7 raising the possibility that the lack of focal hypoperfusion on CTP maps could also be indicative of restored perfusion rather than a limitation of the technique.…”

Self-Supervised Dynamic CT Perfusion Image Denoising With Deep Neural Networks

“…However, CTP faces challenges of high radiation exposure and low spatial resolution compared to DWI despite its advantage in CT's availability [8]. CTP has also been demonstrated to have low sensitivity to lacunar strokes which have small size and composed approximately 20% of all the ischemic stroke, partially due to the artifacts in the parametric maps [59], [60]. A recent study demonstrated the effectiveness of intravenous thrombolysis on lacunar stroke within 4.5 h of symptom onset, which raised the potential needs for fast detection of lacunar stroke [61].…”