[Quantitative perfusion imaging by multi-slice CT in stroke patients].
OBJECTIVE
Evaluation of a parametric deconvolution algorithm (DA) in the diagnostic assessment of stroke patients by multi- slice spiral computed tomography (MS-CT).


METHODS
52 patients (age range 34 - 89 years) with clinically suspected acute ischemia of one hemisphere and no infarct demarcation on plain cerebral CT underwent CT perfusion (CTP), performed on average 3.4 hours after the onset of symptoms by using MS-CT (4 x 8 mm scan volume). Using a DA-based software module, perfusion images of the cerebral blood perfusion (CBP), cerebral blood volume (CBV) and mean transit time (MTT) were calculated and assessed by two readers for visually apparent perfusion abnormalities. Amount and extension of perfusion disturbances were measured and correlated with the outcome.


RESULTS
Of 44 patients, in whom perfusion maps could be generated, territorial infarction was confirmed by follow-up in 22 subjects. With a sensitivity of 95 % ischemia could be detected on MTT-maps (CBP 91 %, CBV 77 %). Specificity was highest (100 %) for CBV-maps. Patients with infarction showed significant (p < 0.001) reduction of CBP (10.7 vs. 38.3 ml/100 ml/min), CBV (1.3 vs. 2.3 ml/100 ml) and prolongation of MTT (12.3 vs. 4.3 s) compared to the contralateral hemisphere, whereas in patients without infarction no significant changes were found. Extension of CBV reduction showed the best correlation (r = 0.82) with final infarct volume.


CONCLUSIONS
The DA-based CTP protocol evaluated in this study is a suitable tool for the early identification and quantification of acute cerebral ischemia.
Bohner
G
G
Abteilung Neuroradiologie, Institut für Radiologie, Charité, Campus Mitte, Humboldt-Universität zu Berlin. georg.bohner@charite.de
Förschler
A
A
Hamm
B
B
Lehmann
R
R
Klingebiel
R
R
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001783:Blood Flow Velocity / Q000502:physiology; D001810:Blood Volume / Q000502:physiology; D001921:Brain / Q000098:blood supply*; D002545:Brain Ischemia / Q000000981:diagnostic imaging*; D002533:Cerebral Angiography / Q000379:methods*; D002544:Cerebral Infarction / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D004292:Dominance, Cerebral / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009460:Neurologic Examination; D011446:Prospective Studies; D012039:Regional Blood Flow / Q000502:physiology; D012680:Sensitivity and Specificity; D036542:Tomography, Spiral Computed / Q000379:methods*