CT Perfusion Confusion

Reading Time: < 1 minute
Rupal Jain
Rupal Jain
Resuscitationist interested in #MedEd and Emergency Radiology. Secret Superpower: x-ray vision, obvs. Other: Audiovisual learner enthusiastic about creating some audiovisual educational content

The Debrief

#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.


  1. 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.
  2. 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 
  3. 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


More Posts

Related Posts

Would love your thoughts, please comment.x