RSNA 2017 CT Preview

Perfusion CT predicts edema after cerebellar stroke

By Abraham Kim, staff writer

November 2, 2017 --

Wednesday, November 29 | 10:30 a.m.-10:40 a.m. | SSK15-01 | Room N226
Which imaging modality is best-suited for predicting malignant cerebellar edema after the occurrence of acute cerebellar stroke? A team of German researchers recently explored this question.

Malignant cerebellar edema "is a serious complication that affects roughly 10% to 20% of patients with acute cerebellar stroke," Drs. Wolfgang Kunz and Matthias Fabritius from Ludwig Maximilian University Hospital told "It requires an opportune diagnosis to avoid direct damage to the brainstem."

To identify imaging parameters to predict malignant cerebellar edema, the researchers analyzed 51 patients with confirmed cerebellar stroke who underwent noncontrast CT, CT angiography, and whole-brain CT perfusion on hospital admission. The perfusion imaging parameters included perfusion deficit volume and posterior circulation Acute Stroke Prognosis Early CT Score (pc-ASPECTS).

Whole-brain CT perfusion maps displayed significantly larger perfusion deficit volumes (p < 0.001) for cerebellar blood flow, cerebellar blood volume, mean transit time, and time to drain, as well as lower median pc-ASPECTS values, in patients who developed malignant cerebellar edema compared with those who did not.

On the other hand, imaging parameters for noncontrast CT and CT angiography did not demonstrate significant differences among patients with or without subsequent malignant cerebellar edema development.

Whole-brain CT perfusion enables early identification of patients at risk of developing cerebellar edema, according to the researchers. Its volume measurement of cerebral blood flow deficit was particularly useful at predicting malignant cerebellar edema, with a cutoff value of 22 mL that resulted in 100% sensitivity and 90% specificity.

"This imaging technique could be applied in future prospective trials that aim at early intervention to reduce the morbidity and mortality of malignant cerebellar stroke," Kunz said.