Alberta Stroke Program Early CT Scoring of CT perfusion in early stroke visualization and assessment

Area of Science:

• Neuroradiology
• Stroke Imaging
• Cerebrovascular Diseases

Background:

• Alberta Stroke Program Early CT Score (ASPECTS) aids infarct extent calculation in middle cerebral artery infarcts.
• Published thresholds for noncontrast CT (NCCT) ASPECTS exist, but early ischemic signs are challenging to detect.
• Hypothesized that distinct ASPECTS thresholds for CT perfusion (CTP) parameters may better predict acute stroke outcomes than NCCT.

Purpose of the Study:

• To determine if different ASPECTS thresholds for CTP parameters compared to NCCT exist.
• To evaluate the superiority of CTP-derived ASPECTS in predicting clinical and radiologic outcomes in acute stroke.
• To identify optimal ASPECTS thresholds for predicting stroke outcomes.

Main Methods:

• 36 acute stroke patients within 3 hours of symptom onset underwent NCCT and CTP.
• Three neuroradiologists blindly assigned ASPECTS to NCCT and CTP datasets.
• Receiver operating characteristic curves were used to derive optimal thresholds for outcome prediction, with treatment response defined as major neurologic improvement.

Main Results:

• Cerebral blood volume (CBV) ASPECTS and NCCT ASPECTS showed similar radiologic correlations (0.6 and 0.5).
• A NCCT ASPECT threshold of 7 and CBV ASPECTS threshold of 8 discriminated patients with poor follow-up scans and unfavorable modified Rankin scores (mRS).
• CBV ASPECTS, unlike NCCT ASPECTS, predicted major neurologic improvement (P = .02), with no patients with CBV ASPECTS <8 achieving good clinical outcome.

Conclusions:

• CBV ASPECTS is equivalent to NCCT ASPECTS for predicting radiologic stroke outcomes.
• CBV ASPECTS may offer additional benefit in predicting patients likely to achieve major neurologic improvement.
• CBV ASPECTS thresholds may be superior to NCCT ASPECTS for predicting acute stroke outcomes.