第42回日本磁気共鳴医学会大会

講演情報

一般演題

大血管-flow

大血管-flow

2014年9月19日(金) 11:20 〜 12:20 第2会場 (3F 源氏の間東)

座長:松永尚文(山口大学大学院医学系研究科 放射線医学分野)

[O-2-148] Quantification of aortic regurgitation using velocity-encoded MRI: Which level should be targeted?

稲毛章郎1, 水野直和2, 杉岡翔2 (1.榊原記念病院 小児循環器科, 2.榊原記念病院 放射線科)

Objective: We sought to demonstrate an accuracy to obtain the aortic regurgitant volume using velocity-encoded cine MRI (VEC).
Methods: We enrolled 12 cases with AR whose VEC were recorded for left ventricular outflow tract (LVOT), aortic annulus, aortic sinus and ascending aorta right pulmonary artery (RPA) levels. We measured the systolic forward flow volume index (FVi), diastolic retrograde flow volume index (RVi) and regurgitant fraction index (RFi = RVi / FVi x 100) at the four levels in during systole. We also measured left ventricular end-diastolic volume index (LVEDVi) and end-systolic volume index (LVESVi), stroke volume index, and ejection fraction. The MRI imaging was obtained using the Siemens MAGNETOM Sonata 1.5T system. The analyses were performed using a workstation (Medis QMass advanced edition & QFlow).
Results: Clinical data were available for 12 patients (mean age of 23.9 +/-3.3 years). We found that the RVi and RFi measured at different levels along the LVOT and ascending aorta RPA level vary significantly. The best correlation between FVi and each of LVEDVi and LVSVi was seen at the aortic annulus (r = 0.64 and 0.68). The best correlation between RVi and LVEDVi was seen at ascending aorta RPA level (r = 0.54). The best correlation between RVi and LVSVi was seen at sinus level (r = 0.58). The best correlation between RFi and each of LVEDVi and LVSVi was seen at the aortic sinus (r = 0.36 to 0.45).
Conclusions: The VEC is accurate measure for quantification of chronic AR. The optimum imaging slice levels for FVi were LVOT and aortic annulus in during systole. The optimum imaging slice levels for RVi and RFi were aortic sinus and ascending aorta RPA level in during systole, and LVOT measurement was possibly underestimated.