UNASSIGNED: A cardiovascular flow phantom was imaged dynamically over different flow rates (0.97 to 2.45 mL/min/g) using 15 mL of contrast per injection. Six swine (37±8 kg) were also imaged dynamically, with different left anterior descending coronary artery balloon stenoses assessed under intracoronary adenosine stress, using 1 mL/kg of contrast per injection. The resulting images were used to simulate dynamic bolus tracking and peak volume scan acquisition. After which, first-pass single-compartment modeling was performed to derive quantitative flow, where the pre-contrast myocardial attenuation was assumed to be spatially uniform. The accuracy of CT flow was then assessed versus ultrasound and microsphere flow in the phantom and animal models, respectively, using regression analysis.
UNASSIGNED: Single-volume quantitative CT flow measurements in the phantom (QCT_PHANTOM) were related to reference ultrasound flow measurements (QUS) by QCT_PHANTOM=1.04 QUS-0.1 (Pearson\'s r=0.98; RMSE=0.09 mL/min/g). In the animal model (QCT_ANIMAL), they were related to reference microsphere flow measurements (QMICRO) by QCT_ANIMAL=1.00 QMICRO-0.05 (Pearson\'s r=0.96; RMSE=0.48 mL/min/g). The effective dose per CT measurement was 1.21 mSv.
UNASSIGNED: The single-volume quantitative CT flow technique only requires bolus tracking data, spatially uniform pre-contrast myocardial attenuation, and a single volume scan acquired near the peak aortic enhancement for accurate, low-dose, myocardial flow measurement (in mL/min/g) under rest and adenosine stress conditions.
使用每次注射15mL造影剂,在不同流速(0.97至2.45mL/min/g)下动态成像心血管血流模型。还对六只猪(37±8千克)进行了动态成像,冠状动脉内腺苷负荷下评估不同的左冠状动脉前降支球囊狭窄,每次注射使用1mL/kg的造影剂。得到的图像用于模拟动态推注跟踪和峰值体积扫描采集。之后,进行了首过单室建模以得出定量流量,假定对比前心肌衰减在空间上是均匀的。然后在体模和动物模型中评估CT流量与超声和微球流量的准确性,分别,使用回归分析。
■体模中的单体积定量CT流量测量(QCT_PHANTOM)与QCT_PHANTOM=1.04QUS-0.1的参考超声流量测量(QUS)相关(Pearson'sr=0.98;RMSE=0.09mL/min/g)。在动物模型(QCT_ANIMAL)中,它们与QCT_ANIMAL=1.00QMICRO-0.05(Pearson\sr=0.96;RMSE=0.48mL/min/g)的参考微球流量测量(QMICRO)相关。每次CT测量的有效剂量为1.21mSv。
■单体积定量CT流量技术仅需要推注跟踪数据,空间均匀的对比前心肌衰减,为了准确,在主动脉增强峰值附近采集的单个体积扫描,低剂量,静息和腺苷应激条件下的心肌血流测量(以mL/min/g为单位)。