Boll Daniel T, Hillenbrand Claudia M, Lewin Jonathan S, Merkle Elmar M
Department of Radiology, University Hospitals of Cleveland, Case Western Reserve University, 11100 Euclid Ave, Cleveland, OH 44106-5056, USA.
Acad Radiol. 2004 Jul;11(7):809-16. doi: 10.1016/j.acra.2004.01.018.
To compare conventional radiofrequency coil reception techniques with parallel coil array acquisition methods in adrenal tissue visualization and to evaluate the dependence of temporal resolution on image quality in adrenal magnetic resonance magnetic resonance (MR) imaging.
Using a 1.5 T MR imager, conventional and parallel sampled sequences were acquired in 10 healthy volunteers and 10 patients with adrenal lesions. The imaging protocol consisted of: conventional (TR/TE 4,730/125 ms; FA 150 degrees; NA 1; AT 25 s), and two parallel imaging SMASH techniques (TR/TE 4,090/125 ms; FA 150 degrees; NA 1 resulting in an AT of 12 s, as well as NA 2 resulting in an AT of 24 s) with generalized autocalibration T(2)-weighted turbo spin echo sequences with 5 mm slice thickness, 1.6 mm in-plane resolution, and an acceleration factor 2. Severity of breathing motion and aliasing artifact and overall image quality were rated on five-point scales and evaluated with student's t test; a differential receiver operating characteristic (DROC) analysis was performed.
Adrenal gland findings included adenomas, metastases, and hemorrhages. Acceleration of conventional turbo spin echo sequence with one signal average led to an increase in diagnostic power (DROC 0.362) as well as significant improvement in overall image quality (P(Volunteers) =.017; P(Patients) =.042) and reduction of breathing motion artifact in patients (P(Patients) =.012) while improving the temporal resolution. Parallel imaging with two signal averages resulted in further improvement of image quality over conventional imaging (DROC 0.303), (P(Volunteers) =.045; P(Patients) =.022), in the same acquisition time as the conventional method.
Parallel acceleration of sequences used for adrenal tissue visualization leads to a significant increase in diagnostic quality by significantly reducing breathing motion artifacts without sacrificing contrast indispensable for adrenal lesion characterization.
比较传统射频线圈接收技术与并行线圈阵列采集方法在肾上腺组织可视化中的效果，并评估肾上腺磁共振成像中时间分辨率对图像质量的依赖性。
使用1.5T磁共振成像仪，对10名健康志愿者和10名肾上腺病变患者进行传统和并行采样序列扫描。成像方案包括：传统序列（TR/TE 4730/125ms；翻转角150°；激励次数1；采集时间25s），以及两种并行成像SMASH技术（TR/TE 4090/125ms；翻转角150°；激励次数1时采集时间为12s，激励次数2时采集时间为24s），采用广义自校准T2加权快速自旋回波序列，层厚5mm，平面分辨率1.6mm，加速因子为2。采用五点量表对呼吸运动和伪影的严重程度以及整体图像质量进行评分，并通过学生t检验进行评估；进行差异接收器操作特性（DROC）分析。
肾上腺检查结果包括腺瘤、转移瘤和出血。传统快速自旋回波序列单次信号平均加速后，诊断能力提高（DROC 0.362），整体图像质量显著改善（志愿者组P = 0.017；患者组P = 0.042），患者呼吸运动伪影减少（患者组P = 0.012），同时时间分辨率提高。在与传统方法相同的采集时间内，两次信号平均的并行成像比传统成像进一步提高了图像质量（DROC 0.303），（志愿者组P = 0.045；患者组P = 0.022）。
用于肾上腺组织可视化的序列并行加速可显著提高诊断质量，通过显著减少呼吸运动伪影，同时不牺牲肾上腺病变特征不可或缺的对比度。
