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Combined SPECT and diffusion-weighted MRI as a predictor of infarct growth in acute ischemic stroke
J O Karonen1, J Nuutinen, J T Kuikka
1Department of Clinical Radiology, Kuopio University Hospital, Finland.
Unlabelled:
In acute ischemic stroke, the infarcted core is surrounded by a zone of tissue that has decreased perfusion. Some of this tissue may be salvaged by prompt, effective treatment. Diffusion-weighted MRI is sensitive in detecting the infarcted tissue, whereas SPECT also detects the hypoperfused tissue around the infarcted core. We studied the potential of combined diffusion-weighted MRI and SPECT to predict infarct growth and clinical outcome in patients not receiving thrombolytic treatment.
Methods:
Sixteen patients with acute stroke were examined consecutively with diffusion-weighted MRI and 99mTc-ethyl cysteinate dimer (99mTc-ECD) SPECT within 24 h of the onset of symptoms. Follow-up diffusion-weighted MRI was performed on the second day and after 1 wk. The volumes of infarcted and hypoperfused brain tissue were measured from diffusion-weighted MRI and SPECT, respectively. The volume difference between the hypoperfused and infarcted tissue on the first day was compared with the possible increase in infarct volume during the follow-up. Each patient's neurologic status was assessed with the National Institutes of Health Stroke Scale (NIHSS).
Results:
The volume of infarcted tissue increased from 48 +/- 54 cm3 (mean +/- SD) on the first day to 88 +/- 93 cm3 on the second day (P = 0.001) and to 110 +/- 121 cm3 at 1 wk (P = 0.001). The volume of hypoperfused tissue on the first day was significantly greater than the infarct volume (102 +/- 135 cm3; P = 0.001). The volume difference between the hypoperfused and infarcted tissue on the first day correlated significantly with the infarct growth between the first day and 1 wk (r = 0.71; P < 0.01). Between the first day and 1 wk, the increase of the infarct volume correlated significantly with the change in the NIHSS (r = 0.54; P < 0.05).
Conclusion:
A large hypoperfusion zone around the infarct core in the acute phase of ischemic stroke predicts the infarct growth during the first week, and this correlates significantly with the change in the neurologic status of the patient. Combined diffusion-weighted MRI and SPECT performed within 24 h after the onset of symptoms can be useful in the evaluation of acute stroke to predict infarct growth.
Insights
A large hypoperfused zone around the infarct core in acute ischemic stroke predicts infarct growth. This imaging approach helps predict patient outcomes and guides treatment decisions.
Area of Science:
- Neurology
- Radiology
- Medical Imaging
Background:
- Acute ischemic stroke involves an infarcted core surrounded by hypoperfused tissue.
- Prompt treatment can salvage some of this at-risk tissue.
- Diffusion-weighted MRI detects infarcts, while SPECT identifies hypoperfused areas.
Purpose of the Study:
- To evaluate the predictive value of combined diffusion-weighted MRI and SPECT for infarct growth and clinical outcome.
- To assess infarct progression in patients not receiving thrombolytic therapy.
Main Methods:
- 16 acute stroke patients underwent diffusion-weighted MRI and 99mTc-ECD SPECT within 24 hours of symptom onset.
- Follow-up MRI was performed on day 2 and at 1 week.
- Volumes of infarcted and hypoperfused tissue were measured; infarct growth was compared to the initial hypoperfusion-infarct volume difference.
Main Results:
- Infarct volume significantly increased from day 1 to 1 week (P = 0.001).
- Initial hypoperfused tissue volume was significantly larger than the infarct core (P = 0.001).
- The initial hypoperfusion-infarct volume difference strongly correlated with infarct growth (r = 0.71; P < 0.01).
Conclusions:
- A substantial hypoperfusion zone in acute ischemic stroke predicts subsequent infarct growth.
- Infarct growth correlates with changes in neurological status (NIHSS).
- Combined diffusion-weighted MRI and SPECT are valuable for predicting acute stroke progression.