title: Reliability of mean transit time obtained using perfusion-weighted MR imaging; comparison with positron emission tomography.
abstract: The purpose of this project was to assess the reliability of the cerebral mean transit time (MTT) obtained using perfusion-weighted MR imaging by comparing it with the MTT obtained when performing positron emission tomography (PET). Ten patients with chronic occlusive cerebrovascular disease were investigated. They had either unilateral internal carotid artery occlusion or middle cerebral artery occlusion. The regions-of-interest were placed in non-infarcted areas within the territory of the middle cerebral artery on the affected side. Control regions-of-interest were placed in mirrored regions of the contralateral side. Linear regression analyses were performed using the parameters of the MTT obtained with perfusion-weighted MR imaging and the MTT, cerebral blood flow, vascular reactivity, and oxygen extraction fraction obtained with PET. The respective MTTs of the affected and non-affected sides obtained with perfusion-weighted MR imaging versus those with PET were 7.3 +/- 2.2 s and 6.0 +/- 1.2 s versus 8.2 +/- 3.0 s and 6.4 +/- 1.7 s. The MTT obtained using perfusion-weighted MR imaging and PET demonstrated statistically significant correlation (r = 0.87, p < 0.0001). The MTT obtained with perfusion-weighted MR imaging correlated statistically with cerebral blood flow (r = -0.74, p < 0.001), vascular reactivity (r = -0.73, p < 0.001) and oxygen extraction fraction (r = 0.61, p < 0.01). Similarly, the MTT obtained using PET statistically correlated with cerebral blood flow (r = -0.78, p < 0.0001), vascular reactivity (r = -0.51, p < 0.05) and oxygen extraction fraction (r = 0.68, p < 0.01). The reliability of the MTT obtained using perfusion-weighted MR imaging appears to be approximately equal to that obtained with positron emission tomography.
authors.affiliation: Department of Clinical Radiology, Kyushu University, Fukuoka, Japan. fmihara@radiol.med.kyushu-u.ac.jp
authors.forename: Futoshi
authors.initials: F
authors.lastname: Mihara
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Kuwabara
authors.forename: Atsuo
authors.initials: A
authors.lastname: Tanaka
authors.forename: Takashi
authors.initials: T
authors.lastname: Yoshiura
authors.forename: Masayuki
authors.initials: M
authors.lastname: Sasaki
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Yoshida
authors.forename: Kouji
authors.initials: K
authors.lastname: Masuda
authors.forename: Toshio
authors.initials: T
authors.lastname: Matsushima
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002544:Cerebral Infarction / Q000175:diagnosis*; D002648:Child; D002908:Chronic Disease; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D015203:Reproducibility of Results; D013997:Time Factors; D014055:Tomography, Emission-Computed