title: Blood flow volume quantification of cerebral ischemia: comparison of three noninvasive imaging techniques of carotid and vertebral arteries.
abstract: OBJECTIVE
  Determination of blood flow volume is useful in assessing ischemic cerebrovascular disease. We compared the blood flow volume measurement of three noninvasive imaging techniques, namely color velocity imaging quantification, spectral Doppler imaging quantification, and MR phase-contrast flow quantification, to see how well the flow values determined by each technique agreed with one another.
  
  
  METHODS
  Flow volume quantification was tested experimentally using a flow simulator and by the three techniques in the vertebral and internal carotid arteries of 40 patients with histories of cerebral ischemia. In the flow simulation study, the flow values in each technique were compared with the phantom flow by the Wilcoxon's signed rank test. In the patient study, the flow values between each paired technique were compared by paired t test. The significance level was taken at p less than 0.05.
  
  
  RESULTS
  Flow volumes were measured by color velocity imaging quantification. MR phase-contrast flow quantification agreed with the phantom flow simulation within the tested range, and spectral Doppler imaging quantification values were significantly overestimated. In patients, a large variation of the blood flow volume was obtained between each technique (p < 0.05). Among them, spectral Doppler imaging quantification showed the highest flow values in the vessels (internal carotid arteries, 312.6 mL/min; vertebral arteries, 112.0 mL/min), followed by color velocity imaging quantification (internal carotid arteries, 216.8 mL/min; vertebral arteries, 58.1 mL/min) and MR phase-contrast flow quantification (internal carotid arteries, 169.1 mL/min; vertebral arteries, 66.5 mL/min).
  
  
  CONCLUSIONS
  Blood flow volume measurements determined by the three noninvasive imaging techniques on the same vessel can differ widely, and spectral Doppler imaging quantification consistently overestimated the flow volume. It is, therefore, essential that the same technique, preferably color velocity imaging quantification or MR phase-contrast flow quantification, be used for clinical follow-up investigations in the future.
authors.affiliation: Department of Diagnostic Radiology and Organ Imaging, Prince of Wales Hospital, Shatin, Hong Kong, China.
authors.forename: Stella Sin Yee
authors.initials: SS
authors.lastname: Ho
authors.forename: Yu Leung
authors.initials: YL
authors.lastname: Chan
authors.forename: David Ka Wai
authors.initials: DK
authors.lastname: Yeung
authors.forename: Constantine
authors.initials: C
authors.lastname: Metreweli
mesh_terms: D001783:Blood Flow Velocity; D001810:Blood Volume; D002545:Brain Ischemia / Q000000981:diagnostic imaging / Q000503:physiopathology*; D002339:Carotid Arteries / Q000000981:diagnostic imaging / Q000503:physiopathology*; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging / Q000503:physiopathology*; D002536:Cerebral Arteries / Q000473:pathology / Q000503:physiopathology; D002560:Cerebrovascular Circulation; D006801:Humans; D018810:Magnetic Resonance Angiography; D008279:Magnetic Resonance Imaging; D019047:Phantoms, Imaging; D011446:Prospective Studies; D018608:Ultrasonography, Doppler; D018615:Ultrasonography, Doppler, Color; D014711:Vertebral Artery / Q000000981:diagnostic imaging / Q000503:physiopathology*