[Quantitative flow measurement of the vertebro-basilar circulation for positional vertigo by using 2D phase contrast technique].
ABSTRACT Quantitative measurements of blood flow in the vertebral and basilar arteries were obtained by the 2D phase contrast (2D PC) technique. In phantom study, flow velocity measured with 2D PC correlated well with actual flow velocity. Sixty-six patients were neurologically normal and 20 had positional vertigo due to vertebrobasilar insufficiency (VBI). Mean velocities (MV) were measured by using a transverse plane in the vertebral arteries at the level of C3 and in the basilar arteries at the level of the sella floor. Volume flow rates (VFR) were calculated as the product of MV and the area of the arteries whose diameters were measured on the basis of pixel counting in the histogram of the signal intensity profile. In the normal group, MV of the left vertebral artery and MV and VFR of the basilar artery showed significant declines as age progressed. In the vertigo group, MV and VFR of the basilar artery were significantly lower than in the normal group. It is concluded that 2D PC technique appears to be fast and easy to handle without cardiac gating to assess blood flow in vessels surrounded by bone tissues.
- SourceAvailable from: Yasushi Iwasaki[show abstract] [hide abstract]
ABSTRACT: Dizziness is a symptom that develops with internal ear disturbances and with dysfunctions of the brain stem and cerebellum, in particular with blood flow disturbances of the brain stem and cerebellum (posterior circulation ischemia [PCI]). Patients with PCI often present with various neurologic signs and symptoms. To examine the usefulness of contrast-enhanced 2D cine phase MR angiography in the diagnosis of PCI, we examined quantitative blood flow of the basilar artery in patients with PCI who had primarily complained of dizziness. We quantitatively measured the blood flow volume rate of the basilar artery by using a contrast-enhanced 2D cine phase MR angiographic technique in 21 patients diagnosed with PCI and in 16 age- and sex-matched control participants. Maximum and mean average flow velocities of the basilar artery in the PCI group were significantly lower than those of the control group (29.2 +/- 9.2 cm/s versus 38.5 +/- 8.2 cm/s [P <.005] and 18.0 +/- 5.6 cm/s versus 22.6 +/- 5.0 cm/s [P <.01], respectively). The flow volume rates of the basilar arteries were also significantly lower in the PCI group (103.3 +/- 37.3 mL/min versus 148.8 +/- 40.0 mL/min [P <.001]). The flow volume rate of the basilar artery in patients with PCI during intermittent ischemic attacks with dizziness was chronically reduced compared with that in the control participants. This suggests that flow volume rates may influence the development of the clinical signs and symptoms of PCI. We think that contrast-enhanced 2D cine phase MR angiography is a valuable method for the diagnosis of PCI.American Journal of Neuroradiology 10/2002; 23(8):1346-51. · 3.17 Impact Factor