Intraplaque high-intensity signal on 3D time-of-flight MR angiography is strongly associated with symptomatic carotid
A Gupta1, H Baradaran, H Kamel
1From the Departments of Radiology (A.G., H.B., V.F., P.C.S.).
Insights
Intraplaque hemorrhage, indicated by high-intensity signal on MRA, strongly predicts prior stroke or TIA in carotid stenosis patients. This finding offers a potential tool for stroke risk stratification.
Area of Science:
- Neuroimaging
- Vascular Medicine
- Radiology
Background:
- Intraplaque hemorrhage (IPH) in carotid arteries is a risk marker for ischemic events.
- High-intensity signal on 3D Time-of-Flight Magnetic Resonance Angiography (3D-TOF MRA) can indicate IPH.
- Association of IPH with prior ipsilateral stroke or transient ischemic attack (TIA) needs further assessment.
Purpose of the Study:
- To evaluate the association between intraplaque high-intensity signal on 3D-TOF MRA and the incidence of prior ipsilateral stroke or TIA.
- To determine if MRA-detected IPH can serve as a predictor of recent ischemic events in patients with high-grade carotid stenosis.
Main Methods:
- Assessed intraplaque hemorrhage using a validated technique for intraplaque high-intensity signal on 3D-TOF MRA source images.
- Included participants with high-grade (≥ 70%) extracranial carotid stenosis.
- Employed logistic regression to analyze the association between intraplaque high-intensity signal and prior stroke or TIA.
Main Results:
- Intraplaque high-intensity signal was detected in 41.5% of 53 carotid arteries studied.
- Patients with intraplaque high-intensity signal had a significantly higher incidence of prior ipsilateral ischemic events (68.1%) compared to those without (12.9%).
- The odds ratio for prior ischemic events associated with intraplaque high-intensity signal was 14.2 (95% CI, 3.3-60.5), with events often occurring within 6 months prior to imaging.
Conclusions:
- Intraplaque high-intensity signal on routine MRA sequences is strongly associated with prior ipsilateral ischemic events.
- This imaging marker could be a valuable and accessible tool for stroke risk stratification in carotid artery stenosis.
- Prospective validation is recommended to confirm its predictive value for patient outcomes.
Background And Purpose:
Intraplaque hemorrhage in carotid artery atherosclerotic plaque has been shown to be a marker of risk, associated with prior and future ischemic events, and has been associated with regions of intraplaque high-intensity signal on 3D-TOF MRA. We assessed the association of intraplaque high-intensity signal determined on 3D-TOF MRA with the incidence of prior ipsilateral stroke or TIA.
Materials And Methods:
We assessed intraplaque hemorrhage by evaluating for intraplaque high-intensity signal adapting a recently validated technique on 3D-TOF source images in participants with high-grade (≥ 70%) extracranial carotid stenosis. Logistic regression analyses were used to assess the strength of association between the presence of intraplaque high-intensity signal on routine MRA sequences and prior stroke or TIA.
Results:
Intraplaque high-intensity signal was present in 22 (41.5%) of 53 carotid arteries studied in 51 patients. Ipsilateral ischemic events occurred in 15 (68.1%) of 22 in the intraplaque high-intensity signal-positive group (10 strokes, 5 TIAs) and in 4 (12.9%) of 31 in the intraplaque high-intensity signal-negative group (3 strokes, 1 TIA). Ischemic events occurred within the 6-month period preceding imaging in 18 (94.7%) of 19 cases. The univariate odds ratio of the association of intraplaque high-intensity signal with any prior ischemic event was 14.5 (95% CI, 3.6-57.6), and the multivariate age- and sex-adjusted odds ratio was 14.2 (95% CI, 3.3-60.5). The association remained present across 1.5 T and 3T magnet field strengths.
Conclusions:
Intraplaque high-intensity signal determined from MRA sequences already in place to measure luminal stenosis is strongly associated with prior ipsilateral ischemic events. Prospective validation of these findings to predict outcome in carotid artery stenosis could provide a valuable and widely accessible stroke risk stratification tool.
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