摘要
背景:先前研究提示,利用相位对比MR成像(PC-MRI)无创性定量检测血管跨狭窄压力阶差(ΔP)是可行的。
Background:Previous studies have suggested the feasibility of a non-invasive quantification of vascular trans-stenotic pressure gradients(ΔP) by phase-contrast MR imaging(PC-MRI). Our purpose was to assess the value of MRI estimated pressure gradients as a screening tool for assessing hemodynamically significant(re-)coarctation of the aorta(CoA) in pediatric patients. Methods:Forty-three patients(median age(range),16(5-25) years) with CoA(38 postoperative and 5 native) and clinically suspected hemodynamically significant stenosis underwent quantitative and semi-quantitative PC-MRI blood flow measurements and 3D MR-angiography,Doppler ultrasound(US) and conventional catheter angiography(CCA,n=20). Estimated ΔP for each modality was correlated with percent stenosis. Results:The percent stenosis correlated only moderately with ΔPMRI(r=0.55,p< 0.001) and ΔPCCA(r=0.48,p< 0.001). Only moderate correlations were observed between ΔPMRI vs. ΔPCCA(r=0.54,p=0.02) and vs. ΔPUS(r=0.40,p=0.01). In contrast,semi-quantitative analysis of PC-MRI flow profiles predicted with good sensitivity(88%) and specificity(88%) who would be operated on. Thirteen patients met hemodynamic and percent stenosis criteria by CCA for surgical intervention. Conclusion:Measured pressure gradients using PC-MRI should be used cautiously when assessing patients for recoarctation of the aorta. The analysis of blood flow profiles by PC-MRI might be a promising alternative in assessing the hemodynamic significance of CoA.
