Opercular Score Index can be used to predict the collateral robustness or the strength of vascular network in stroke patients.

"The Opercular Index Score is a potentially useful method and supplement to CT Perfusion imaging in telling us which patients may benefit most from invasive stroke treatment," said Dr. Alexander Copelan, a diagnostic radiology resident at Beaumont Health System in Royal Oak, Michigan, and the study's principal investigator and lead author.
"Among the main advantages are its simplicity and ease in calculation based on readily available CT data without having to scan and inject the patient with intravenous contrast a second time. "Nearly 130,000 people in the U.S. die from stroke each year. The vast majority of strokes -- 87 percent-- are ischemic strokes, caused by a blocked artery in the brain.
Source-Eurekalert