title: Perfusion computed tomography evaluation of cerebral hemodynamic impairment in patients with unilateral chronic steno-occlusive disease: a comparison with the acetazolamide challenge 99mTc-hexamethylpropyleneamine oxime single-photon emission computed tomography.
abstract: OBJECTIVE
  The purpose of this study was to determine which pefusion computed tomography (PCT) parameter is the most valid predictor of cerebral vascular reserve (CVR) as determined by Tc-hexamethylpropyleneamine oxime single-photon emission computed tomography (SPECT).
  
  
  METHODS
  Single-photon emission computed tomography with acetazolamide challenge and PCT were used in 23 patients with unilateral steno-occlusive vascular disease. After coregistration of the PCT and SPECT images, we assessed the relationship between the PCT parameters and SPECT findings and the predictive values of the PCT parameters for decreased CVR.
  
  
  RESULTS
  All PCT parameters of cerebral blood flow, cerebral blood volume, and mean transit time (MTT) were significantly correlated with SPECT regional cerebral blood flow ratios (P < 0.01). The MTT values more strongly correlated with acetazolamide effect than with cerebral blood volume or cerebral blood flow (P < 0.001). The MTT difference (values in the pathological hemisphere minus the values in the contralateral hemisphere) was a threshold of 1.5 seconds, with a sensitivity of 88% and a specificity of 70% for predicting decreased CVR.
  
  
  CONCLUSIONS
  Mean transit time is the most predictive parameter for assessing decreased CVR in patients with unilateral steno-occlusive vascular disease.
authors.affiliation: Department of Radiology and Institute of Radiation Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Eunhee
authors.initials: E
authors.lastname: Kim
authors.forename: Chul-Ho
authors.initials: CH
authors.lastname: Sohn
authors.forename: Dong Gyu
authors.initials: DG
authors.lastname: Na
authors.forename: Jeong Eun
authors.initials: JE
authors.lastname: Kim
authors.forename: Kee-Hyun
authors.initials: KH
authors.lastname: Chang
authors.forename: Ji-Hoon
authors.initials: JH
authors.lastname: Kim
authors.forename: Se Jeong
authors.initials: SJ
authors.lastname: Jeon
mesh_terms: D000086:Acetazolamide; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001810:Blood Volume; D001921:Brain / Q000098:blood supply / Q000000981:diagnostic imaging; D002257:Carbonic Anhydrase Inhibitors; D016893:Carotid Stenosis / Q000000981:diagnostic imaging*; D002560:Cerebrovascular Circulation; D002561:Cerebrovascular Disorders / Q000000981:diagnostic imaging*; D002908:Chronic Disease; D003287:Contrast Media; D005260:Female; D006801:Humans; D007472:Iohexol / Q000031:analogs & derivatives; D008297:Male; D008875:Middle Aged; D010091:Oximes; D055420:Perfusion Imaging / Q000379:methods; D011237:Predictive Value of Tests; D011856:Radiographic Image Enhancement / Q000379:methods; D012039:Regional Blood Flow; D015203:Reproducibility of Results; D013667:Technetium; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D002257:Carbonic Anhydrase Inhibitors; D003287:Contrast Media; D010091:Oximes; C068296:hexamethylpropyleneamine oxime; D007472:Iohexol; C038192:iopromide; D013667:Technetium; D000086:Acetazolamide