title: Perfusion CT: Additional Diagnostic and Clinical Information in MCA Stroke.
abstract: With multidetector computed tomography equipment it is possible to identify early signs of ischemia on non-enhanced CT (NECT) and have access to cerebral hemodynamics using perfusion CT (PCT). Based on specific patterns of hemodynamic changes of cerebral blood flow, cerebral blood volume and mean transit time it is feasible to create probability maps of brain tissue and calculate de potential recuperation ratio. The difference between irreversible and reversible brain damage or "tissue at risk" is essential for choosing an appropriate therapy. We evaluated the sensitivity of NECT and PCT in the diagnosis of middle cerebral artery (MCA) ischemic stroke, established their correlation with the clinical evaluation and analysed their changes in time. Thirty patients with MCA ischemic stroke underwent NECT and PCT in the acute T1 (M=7,0 h; min=0,50; max=24), subacute T2 (M=5,0 d; min=2,0; max=14,0) and chronic phase T3 (M=39,1 d; min=28,0; max=61,0). Clinical assessment and outcome were rated using the modified National Institute of Health Stroke Scale (mNIHSS). In the diagnosis of MCA stroke, PCT was more sensitive (83%) than NECT (70%). On admission, compared MTT values (r=0,560) and cerebral ischemic volume (CIV) (r=0,486) correlated with the clinical severity. Initial NECT changes correlated with the clinical evolution in T2 (r=-0,403) and T3 (r=-0,363). The PRR decreased over time, but it demonstrated a large variation for the same time period. The association of NECT with PCT can yield an early stroke diagnosis. It may possibly predict clinical severity and outcome. In addition, this association could provide an insight into the extent of penumbra and quantify the PRR, which is of paramount importance in therapeutic decision-making.
authors.affiliation: Neuroradiology Unit, Radiology Department, Prof. Dr. Fernando Fonseca Hospital; Lisbon, Portugal - leonorlm@gmail.com.
authors.forename: L
authors.initials: L
authors.lastname: Lopes