Tandon Animesh, Hashemi Sassan, Parks W James, Kelleman Michael S, Sallee Denver, Slesnick Timothy C
Departments of Pediatrics, Radiology, and Biomedical Engineering, University of Texas Southwestern Medical School, Dallas, TX, USA.
Children's Medical Center Dallas, Dallas, TX, USA.
J Cardiovasc Magn Reson. 2016 Nov 2;18(1):74. doi: 10.1186/s12968-016-0296-4.
Improved delineation of vascular structures is a common indication for cardiovascular magnetic resonance (CMR) in children and requires high spatial resolution. Currently, pre-contrast 3D, respiratory navigated, T2-prepared, fat saturated imaging with a bSSFP readout (3D bSSFP) is commonly used; however, these images can be limited by blood pool inhomogeneity and exaggeration of metal artifact. We compared image quality of pediatric vasculature obtained using standard 3D bSSFP to 3D, respiratory navigated, inversion recovery prepared imaging with a gradient echo readout (3D IR GRE) performed after administration of gadofosveset trisodium (GT), a blood pool contrast agent.
For both sequences, VCG triggering was used with acquisition during a quiescent period of the cardiac cycle. 3D bSSFP imaging was performed pre-contrast, and 3D IR GRE imaging was performed 5 min after GT administration. We devised a vascular imaging quality score (VIQS) with subscores for coronary arteries, pulmonary arteries and veins, blood pool homogeneity, and metal artifact. Scoring was performed on axial reconstructions of isotropic datasets by two independent readers and differences were adjudicated. Signal- and contrast-to-noise (SNR and CNR) calculations were performed on each dataset.
Thirty-five patients had both 3D bSSFP and 3D IR GRE imaging performed. 3D IR GRE imaging showed improved overall vascular imaging compared to 3D bSSFP when comparing all-patient VIQS scores (n = 35, median 14 (IQR 11-15), vs 6 (4-10), p < 0.0001), and when analyzing the subset of patients with intrathoracic metal (n = 17, 16 (14-17) vs. 5 (2-9), p < 0.0001). 3D IR GRE showed significantly improved VIQS subscores for imaging the RCA, pulmonary arteries, pulmonary veins, and blood pool homogeneity. In addition, 3D IR GRE imaging showed reduced variability in both all-patient and metal VIQS scores compared to 3D bSSFP (p < 0.05). SNR and CNR were higher with 3D IR GRE in the left ventricle and left atrium, but not the pulmonary arteries.
Respiratory navigated 3D IR GRE imaging after GT administration provides improved vascular CMR in pediatric patients compared to pre-contrast 3D bSSFP imaging, as well as improved imaging in patients with intrathoracic metal. It is an excellent alternative in this challenging patient population when high spatial resolution vascular imaging is needed.
改善血管结构的描绘是儿童心血管磁共振成像（CMR）的常见指征，且需要高空间分辨率。目前，常用的是对比剂前的三维、呼吸导航、T2准备、脂肪饱和的bSSFP读出成像（3D bSSFP）；然而，这些图像可能受到血池不均匀性和金属伪影夸大的限制。我们比较了使用标准3D bSSFP获得的儿科血管图像质量与注射钆特醇三钠（GT，一种血池造影剂）后进行的三维、呼吸导航、反转恢复准备的梯度回波读出成像（3D IR GRE）。
对于这两种序列，在心动周期的静止期使用心电图门控触发采集。3D bSSFP成像在注射对比剂前进行，3D IR GRE成像在注射GT后5分钟进行。我们设计了一个血管成像质量评分（VIQS），包括冠状动脉、肺动脉和静脉、血池均匀性以及金属伪影的子评分。由两名独立的阅片者对各向同性数据集的轴向重建进行评分，并对差异进行判定。对每个数据集进行信号和对比噪声（SNR和CNR）计算。
35例患者同时进行了3D bSSFP和3D IR GRE成像。比较所有患者的VIQS评分时（n = 35，中位数14（四分位间距11 - 15），对比6（4 - 10），p < 0.0001），以及分析有胸腔内金属的患者亚组时（n = 17，16（14 - 1
