Abstract：
BACKGROUND: In patients who have difficulty holding their breath, a free breathing (FB) respiratory-triggered (RT) bSSFP cine technique may be used. However, this technique may have inferior image quality and a longer scan time than breath-hold (BH) bSSFP cine acquisitions. This study examined the effect of an audiovisual breathing guidance (BG) system on RT bSSFP cine image quality, scan time, and ventricular measurements.
METHODS: This study evaluated a BG system that provides audiovisual instructions and feedback on the timing of inspiration and expiration to the patient during image acquisition using input from the respiratory bellows to guide them toward a regular breathing pattern with extended end-expiration. In this single-center prospective study in patients undergoing a clinical cardiac magnetic resonance examination, a ventricular short-axis stack of bSSFP cine images was acquired using 3 techniques in each patient: 1) FB and RT (FBRT), 2) BG system and RT (BGRT), and 3) BH. The 3 acquisitions were compared for image quality metrics (endocardial edge definition, motion artifact, and blood-to-myocardial contrast) scored on a Likert scale, scan time, and ventricular volumes and mass.
RESULTS: Thirty-two patients (19 females; median age 21 years, IQR 18-32) completed the study protocol. For scan time, BGRT was faster than FBRT (163 s vs. 345 s, p < 0.001). Endocardial edge definition, motion artifact, and blood-to-myocardial contrast were all better for BGRT than FBRT (p < 0.001). Left ventricular (LV) end-systolic volume (ESV) was smaller (3%, p = 0.02) and LV ejection fraction (EF) was larger (0.5%, p = 0.003) with BGRT than with FBRT. There was no significant difference in LV end-diastolic volume (EDV), LV mass, right ventricular (RV) EDV, RV ESV, and RV EF. Scan times were shorter for BGRT compared to BH. Endocardial edge definition and blood-to-myocardial contrast were better for BH than BGRT. Compared to BH, the LV EDV, LV ESV, RV EDV, and RV ESV were mildly smaller (all differences <7%) for BGRT.
CONCLUSIONS: The addition of a BG system to RT bSSFP cine acquisitions decreased the scan time and improved image quality. Further exploration of this BG approach is warranted in more diverse populations and with other free breathing sequences.
METHODS: This study evaluated a BG system that provides audiovisual instructions and feedback on the timing of inspiration and expiration to the patient during image acquisition using input from the respiratory bellows to guide them toward a regular breathing pattern with extended end-expiration. In this single-center prospective study in patients undergoing a clinical cardiac magnetic resonance examination, a ventricular short-axis stack of bSSFP cine images was acquired using 3 techniques in each patient: 1) FB and RT (FBRT), 2) BG system and RT (BGRT), and 3) BH. The 3 acquisitions were compared for image quality metrics (endocardial edge definition, motion artifact, and blood-to-myocardial contrast) scored on a Likert scale, scan time, and ventricular volumes and mass.
RESULTS: Thirty-two patients (19 females; median age 21 years, IQR 18-32) completed the study protocol. For scan time, BGRT was faster than FBRT (163 s vs. 345 s, p < 0.001). Endocardial edge definition, motion artifact, and blood-to-myocardial contrast were all better for BGRT than FBRT (p < 0.001). Left ventricular (LV) end-systolic volume (ESV) was smaller (3%, p = 0.02) and LV ejection fraction (EF) was larger (0.5%, p = 0.003) with BGRT than with FBRT. There was no significant difference in LV end-diastolic volume (EDV), LV mass, right ventricular (RV) EDV, RV ESV, and RV EF. Scan times were shorter for BGRT compared to BH. Endocardial edge definition and blood-to-myocardial contrast were better for BH than BGRT. Compared to BH, the LV EDV, LV ESV, RV EDV, and RV ESV were mildly smaller (all differences <7%) for BGRT.
CONCLUSIONS: The addition of a BG system to RT bSSFP cine acquisitions decreased the scan time and improved image quality. Further exploration of this BG approach is warranted in more diverse populations and with other free breathing sequences.
摘要：
背景：在呼吸困难的患者中，可以使用自由呼吸（FB）呼吸触发（RT）bSSFP电影技术。然而,与屏气(BH)bSSFP电影采集相比,该技术可能具有较差的图像质量和更长的扫描时间.这项研究检查了视听呼吸指导（BG）系统对RTbSSFP电影图像质量的影响，扫描时间,和心室测量。
方法：本研究评估了一种BG系统，该系统在图像采集过程中使用呼吸波纹管的输入向患者提供有关吸气和呼气定时的视听指示和反馈，以引导他们朝着具有延长呼气末的规律呼吸模式。在这项针对接受临床心脏磁共振检查的患者的单中心前瞻性研究中，在每位患者中使用3种技术获取bSSFP电影图像的心室短轴堆叠：1）FB和RT（FBRT），2）BG系统和RT（BGRT），3）BH。比较了3次采集的图像质量度量(心内膜边缘定义，运动伪影,和血液-心肌造影)在李克特量表上评分，扫描时间,和心室容积和质量。
结果：32名患者（19名女性；中位年龄21岁，IQR18-32）完成了研究方案。对于扫描时间，BGRT比FBRT快（163svs.345s,p<0.001)。心内膜边缘定义,运动伪影,BGRT和血液-心肌造影均优于FBRT（p<0.001）。左心室（LV）收缩末期容积（ESV）较小（3%，p=0.02)和左心室射血分数(EF)更大(0.5%，p=0.003)用BGRT比用FBRT。左室舒张末期容积(EDV)无显著差异,低压质量,右心室(RV)EDV,RVESV,和RVEF。与BH相比，BGRT的扫描时间更短。BH的心内膜边缘定义和血液与心肌对比比BGRT更好。与BH相比,LVEDV,LVESV,RVEDV,对于BGRT，RVESV略小（所有差异<7％）。
结论：在RTbSSFP电影采集中添加BG系统缩短了扫描时间并提高了图像质量。在更多样化的人群和其他自由呼吸序列中，需要对这种BG方法进行进一步的探索。
方法：本研究评估了一种BG系统，该系统在图像采集过程中使用呼吸波纹管的输入向患者提供有关吸气和呼气定时的视听指示和反馈，以引导他们朝着具有延长呼气末的规律呼吸模式。在这项针对接受临床心脏磁共振检查的患者的单中心前瞻性研究中，在每位患者中使用3种技术获取bSSFP电影图像的心室短轴堆叠：1）FB和RT（FBRT），2）BG系统和RT（BGRT），3）BH。比较了3次采集的图像质量度量(心内膜边缘定义，运动伪影,和血液-心肌造影)在李克特量表上评分，扫描时间,和心室容积和质量。
结果：32名患者（19名女性；中位年龄21岁，IQR18-32）完成了研究方案。对于扫描时间，BGRT比FBRT快（163svs.345s,p<0.001)。心内膜边缘定义,运动伪影,BGRT和血液-心肌造影均优于FBRT（p<0.001）。左心室（LV）收缩末期容积（ESV）较小（3%，p=0.02)和左心室射血分数(EF)更大(0.5%，p=0.003)用BGRT比用FBRT。左室舒张末期容积(EDV)无显著差异,低压质量,右心室(RV)EDV,RVESV,和RVEF。与BH相比，BGRT的扫描时间更短。BH的心内膜边缘定义和血液与心肌对比比BGRT更好。与BH相比,LVEDV,LVESV,RVEDV,对于BGRT，RVESV略小（所有差异<7％）。
结论：在RTbSSFP电影采集中添加BG系统缩短了扫描时间并提高了图像质量。在更多样化的人群和其他自由呼吸序列中，需要对这种BG方法进行进一步的探索。
