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Updated: Apr 16, 2026
A Magnetic Resonance Imaging Protocol for Stroke Onset Time Estimation in Permanent Cerebral Ischemia
Published on: September 16, 2017
Optimal MRI sequence for identifying occlusion location in acute stroke: which value of time-resolved
A Le Bras1, H Raoult2, J-C Ferré2
1From the Departments of Neuroradiology (A.L.B., H.R., J.-C.F., J.-Y.G.) anthony.le.bras@chu-rennes.fr.
Background And Purpose:
Identifying occlusion location is crucial for determining the optimal therapeutic strategy during the acute phase of ischemic stroke. The purpose of this study was to assess the diagnostic efficacy of MR imaging, including conventional sequences plus time-resolved contrast-enhanced MRA in comparison with DSA for identifying arterial occlusion location.
Materials And Methods:
Thirty-two patients with 34 occlusion levels referred for thrombectomy during acute cerebral stroke events were consecutively included from August 2010 to December 2012. Before thrombectomy, we performed 3T MR imaging, including conventional 3D-TOF and gradient-echo T2 sequences, along with time-resolved contrast-enhanced MRA of the extra- and intracranial arteries. The 3D-TOF, gradient-echo T2, and time-resolved contrast-enhanced MRA results were consensually assessed by 2 neuroradiologists and compared with prethrombectomy DSA results in terms of occlusion location. The Wilcoxon test was used for statistical analysis to compare MR imaging sequences with DSA, and the κ coefficient was used to determine intermodality agreement.
Results:
The occlusion level on the 3D-TOF and gradient-echo T2 images differed significantly from that of DSA (P < .001 and P = .002, respectively), while no significant difference was observed between DSA and time-resolved contrast-enhanced MRA (P = .125). κ coefficients for intermodality agreement with DSA (95% CI, percentage agreement) were 0.43 (0.3%-0.6; 62%), 0.32 (0.2%-0.5; 56%), and 0.81 (0.6%-1.0; 88%) for 3D-TOF, gradient-echo T2, and time-resolved contrast-enhanced MRA, respectively.
Conclusions:
The time-resolved contrast-enhanced MRA sequence proved reliable for identifying occlusion location in acute stroke with performance superior to that of 3D-TOF and gradient-echo T2 sequences.
Insights
Time-resolved contrast-enhanced MRA accurately identifies arterial occlusion location in acute stroke, outperforming conventional MR sequences. This imaging technique is crucial for effective treatment planning.
Area of Science:
- Neurology
- Radiology
- Medical Imaging
Background:
- Accurate identification of arterial occlusion location is critical for timely and effective treatment of acute ischemic stroke.
- Conventional MR imaging sequences have limitations in precisely pinpointing the site of arterial blockages.
Purpose of the Study:
- To evaluate the diagnostic accuracy of MR imaging, including conventional sequences and time-resolved contrast-enhanced MR angiography (CE-MRA), in identifying arterial occlusion locations.
- To compare the efficacy of these MR techniques against digital subtraction angiography (DSA) for stroke treatment planning.
Main Methods:
- 32 patients with acute cerebral stroke underwent 3T MR imaging, including 3D-Time-of-Flight (TOF) and gradient-echo T2 sequences, plus time-resolved CE-MRA.
- Results from MR imaging sequences were compared with pre-thrombectomy digital subtraction angiography (DSA) for occlusion site identification.
- Statistical analysis used the Wilcoxon test and κ coefficient to assess agreement and differences between imaging modalities.
Main Results:
- Time-resolved CE-MRA showed no significant difference compared to DSA in identifying occlusion location (P = .125).
- Conventional 3D-TOF and gradient-echo T2 sequences demonstrated significant differences from DSA (P < .001 and P = .002, respectively).
- Intermodality agreement with DSA was highest for time-resolved CE-MRA (κ = 0.81, 88% agreement), compared to 3D-TOF (κ = 0.43, 62%) and gradient-echo T2 (κ = 0.32, 56%).
Conclusions:
- Time-resolved contrast-enhanced MRA is a reliable method for determining arterial occlusion location in acute stroke patients.
- This advanced MR technique offers superior performance compared to traditional 3D-TOF and gradient-echo T2 sequences for this diagnostic purpose.
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