肺動脈流速測定における三次元シネ位相コントラスト磁気共鳴法の撮像パラメータの検討

摘要

Pulmonary artery flow velocity, flow volume and their derived biomarkers, such as acceleration time (AT), acceleration volume (AV) and peak velocity (PV), vary depending on the severity and type of pulmonary disease. Therefore, accurate measurements of pulmonary artery velocity are very important for assessing the severity of pulmonary disease. The purpose of this study was to optimize the imaging parameters for pulmonary artery flow velocity using 3D cine PC MR, and to evaluate AT, AV, and PV for pulmonary hypertension. We changed the flip angle (FA) and view per segment (VPS). FA influenced the signal intensity, which was calculated from the magnitude images. Smaller VPS improved the accuracy of PV. Consequently, optimal setting of FA and VPS was important for hemodynamic analysis. We established the optimal FA and VPS for use in the hemodynamic analysis. AV and PV at the right pulmonary artery differed significantly between healthy volunteers and patients with pulmonary hypertension. Hemodynamic analysis of 3D cine PC MR imaging was considered promising for the evaluation of pulmonary disease.%磁気共鳴画像(magnetic resonance imaging: MRI)で血流情報収集が可能である.その一つの方法に，心電図と同期させ，各心時相の流速によって生じる位相変化を信号として画像化するシネ位相コントラスト磁気共鳴法(Cine Phase Contrast MR: cine PC MR)が存在する.現在報告されているのは，二次元でデータ収集を行う二次元(two dimensional: 2D) cine PC MRである.近年，装置や高速撮像法の発展により三次元でのデータ収集を行う三次元(three dimensional: 3D)cine PC MRが撮像可能となってきたが，撮像パラメータや臨床的有用性は十分に報告されていないのが現状である.