Flow Quantification In PCI: Measurement With Cine Phase-Contrast MR Imaging

There are two parts in our study:the first part,To evaluate the accuracy of Cine Phase-contrast MR Flow measurement by a model of steady fluid model;The second part,Using this method,with TCD as a reference,to measure vertebral artery rate in patients with PCI.Part one Experimental Study of Steady Fluid Flow Velocity with Cine Phase-Contrast MR0bjective To evaluate the accuracy of Cine Phase-Contrast MR flow measurement.Materials and methods Tube flow phantoms were established.Flow velocity of the steady flow in tubes(3mm2,5mm2) was measured by Cine Phase-Contrast MR when the rate of syringes injection was 0.1ml/s,0.2ml/s and 0.3ml/s correspondingly. The correlation analysis were made and the transform function formulas of the model were also obtained by the SPSS.Results Mode velocity and the corresponding PC-MR velocity showed a linear correlation (r=.992; p=.0001, Model velocity(y)=9.47×MR velocity (x)). Conclusion After correction, measurement of flow with the use of Cine-PC-MR is feasible and accurate.Part two Cine Phase-Contrast MR Flow Quantification in PCI with Comparison to TCD Measurements0bjective Using Cine phase-contrast MR,with TCD as a reference, to measure vertebral artery rate in patients with PCI and to Explore the reasons for PCI. Materials and Methods Hemodynamic parameters of both vertebral artery were measured with Cine Phase-Contrast MR in 28 patients of posterior circulation ischemia and 5 normal volunteers using head coil and periphery pulse gate control technology. In addition, all patients were examined by TCD. Correlation analysis of flow values measured by two techniques was done and flow value between PCI and normal volunteers was compared by t-test, a comparison of MR velocity with vascular stenosis was done.Results In patients with PCI, flow velocity of vertebral artery assessed by using Cine phase-contrast MR and TCD showed good correlation (LVA r=.887,p=0.013; RVA r=.785,p=0.027).Cine Phase Contrast MR velocity: LVA (16.16±7.99)cm/s, RVA(15.72±9.92)cm/s; blood flow :LVA(66.63±45.23) ml/min, RVA(68.57±38.84) ml/min. There has significant difference between normal volunteers and PCI(LVA p=.003;RVA p=.002) .Cine phase-contrast MR blood flow measurements correlated poorly with the vascular stenosis (r=-.144,p=.654).Conclusion Measurement of hemodynamic parameters noninvasively in patients with PCI with the use of Cine Phase Contrast MR is feasible. However, blood flow and vascular stenosis was poorly correlated.