Related Experiment Video
Updated: Aug 18, 2026
Brain Infarct Segmentation and Registration on MRI or CT for Lesion-symptom Mapping
Published on: September 25, 2019
Tissue at risk is overestimated in perfusion-weighted imaging: MR imaging in acute stroke patients without vessel
Thomas Kucinski1, Dirk Naumann, René Knab
1Department of Neuroradiology, University Hospital Hamburg-Eppendorf, Hamburg, Germany.
Background And Purpose:
The volume of decreased cerebral blood flow (CBF) in acute stroke perfusion-weighted imaging frequently overestimates final infarct volume. We hypothesized that surviving tissue exists even in patients without recanalization and tried to determine perfusion thresholds from initial MR imaging.
Methods:
Stroke MR imaging including MR angiography was carried out at days 0, 1, and 7 after stroke onset in 19 patients without recanalization at least until day 1. The following lesions were defined: L0 = diffusion restriction at day 0; LG1 = lesion growth until day 1; LG7 = lesion growth until day 7; ST7 = initially hypoperfused, but surviving tissue. These lesions were transferred on initial MR imaging within 4.7 hours and perfusion values at day 0 were determined.
Results:
Median lesion volume L0 at day 0 was 18.2 mL and increased to 39.4 and 43.8 mL at days 1 and 7. Volume of decreased rCBF not progressing to infarction was 148.5 mL (ST7). Mean ST7 perfusion values were different from L0 and LG1, but only mean relative cerebral blood volume (rCBV) was different from LG7, discriminating survival against death of tissue. A threshold value of 0.82 CBV for death versus survival was determined with a sensitivity of 0.56 and specificity of 0.95. Carotid T occlusions showed the greatest potential of lesion growth.
Conclusion:
Even when vessel occlusion persists, hypoperfused tissue on MR imaging does not necessarily progress toward infarction. The most conclusive inferences can be drawn from CBV images. The site of arterial occlusion also determines progression to infarction.
Insights
Even without recanalization, hypoperfused brain tissue may survive acute stroke. Cerebral blood volume (CBV) imaging can identify this viable tissue, aiding in stroke assessment.
Area of Science:
- Neurology
- Radiology
- Medical Imaging
Background:
- Acute stroke perfusion imaging often overestimates final infarct volume.
- Hypoperfused tissue may survive even without recanalization in acute stroke patients.
- Initial MR imaging can help determine perfusion thresholds for tissue survival.
Purpose of the Study:
- To investigate the existence of surviving tissue in patients with persistent vessel occlusion.
- To establish perfusion thresholds from initial MR imaging to predict tissue outcome.
- To analyze the relationship between perfusion deficits and final infarct volume.
Main Methods:
- Stroke MR imaging and MR angiography were performed on 19 patients without recanalization.
- Lesions were defined based on diffusion restriction and growth over 7 days.
- Perfusion values, including relative cerebral blood volume (rCBV), were determined within 4.7 hours of stroke onset.
Main Results:
- A significant volume of hypoperfused tissue (148.5 mL) did not progress to infarction.
- Relative cerebral blood volume (rCBV) was a key differentiator between surviving and infarcted tissue.
- A CBV threshold of 0.82 demonstrated high specificity (0.95) and moderate sensitivity (0.56) for predicting tissue survival.
- Carotid artery occlusions were associated with the greatest potential for lesion growth.
Conclusions:
- Hypoperfused tissue identified on MR imaging may not inevitably lead to infarction, even with persistent vessel occlusion.
- Cerebral blood volume (CBV) imaging provides the most reliable information for assessing tissue viability.
- The location of arterial occlusion significantly influences the progression of stroke to infarction.
Related Concept Videos
01:24Magnetic Resonance Imaging
01:15Ischemic Stroke ll: Pathophysiology