NEURORADIOLOGY: Vascular
Case Author: Megan K. Strother, MD, Vanderbilt University Medical Center
History
22-year-old man with sudden left-sided weakness.
Imaging Findings
Parametric maps from CT perfusion study show decreased cerebral blood flow (A), decreased cerebral blood volume (B), and delayed mean transit time (C) in the right anterior and middle cerebral artery territories.
- Infarction
- Ischemia
- Seizure, interictal
- Vasospasm
Diagnosis
Infarction
Teaching Points
When CT is performed correctly, at 80 kVp and 200 mAs, the effective radiation dose for a CT perfusion study is approximately equivalent (2–3 mSv) to that of head CT. CT perfusion maps should be interpreted in conjunction with CT scans and CT angiograms and knowledge of the clinical presentation. Debate continues regarding which CT perfusion parameters best identify penumbra and infarct core. In general, an infarct core exhibits decreased cerebral blood volume and cerebral blood flow with increased mean transit time (or time to peak).
Suggested Readings
Deibler AR, Pollock JM, Kraft RA, Tan H, Burdette JH, Maldjian JA. Arterial spin-labeling in routine clinical practice. Part 2. Hypoperfusion patterns. AJNR 2008; 29:1235–1241
Konstas AA, Wintermark M, Lev MH. CT perfusion imaging in acute stroke. Neuroimaging Clin N Am 2011; 21:215–238
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