#1: CT perfusion allows us to identify tissue that is irreversibly dead (infarcted core) versus that which is salvageable (ischemic penumbra) in a patient with suspected large vessel occlusion. When there is a mismatch between infarcted core and ischemic penumbra (i.e. ~ mismatch volume of 15mL or mismatch ratio > 1.8), this indicates thrombectomy may reverse some functional damage.
#2: Currently, most protocols entail scanning 1-2 slabs of the brain. The increased scan time in a short segment of the brain confers increased radiation to this tissue. Therefore it is important to choose this scan wisely.
- Kanal, E., Barkovich, A., Bell, C., Borgstede, J., Bradley, W., Froelich, J., Gimbel, J., Gosbee, J., Kuhni-Kaminski, E., Larson, P., Lester, J., Nyenhuis, J., Schaefer, D., Sebek, E., Weinreb, J., Wilkoff, B., Woods, T., Lucey, L. and Hernandez, D., 2020. ACR Guidance Document On MR Safe Practices: 2013.
- Allmendinger AM, Tang ER, Lui YW, Spektor V. Imaging of Stroke: Part 1, Perfusion CT???Overview of Imaging Technique, Interpretation Pearls, and Common Pitfalls. American Journal of Roentgenology. 2012;198(1):52-62. doi:10.2214/ajr.10.7255
- Hoeffner EG, Case I, Jain R, Gujar SK, Shah GV, Deveikis JP, Carlos RC, Thompson BG, Harrigan MR, Mukherji SK. Cerebral Perfusion CT: Technique and Clinical Applications1. (2004) Radiology. 231 (3): 632-44. doi:10.1148/radiol.2313021488