标题：Four-Dimensional Magnetic Resonance Imaging Using Axial Body Area as Respiratory Surrogate: Initial Patient Results
作者：Yang, Juan; Cai, Jing; Wang, Hongjun; Chang, Zheng; Czito, Brian G.; Bashir, Mustafa R.; Yin, Fang-Fang
作者机构：[Yang, Juan; Cai, Jing; Chang, Zheng; Czito, Brian G.; Yin, Fang-Fang] Duke Univ, Med Ctr, Dept Radiat Oncol, Durham, NC 27710 USA.; [Bashir, Mustaf 更多
通讯作者地址：[Yin, FF]Duke Univ, Med Ctr, Dept Radiat Oncol, Box 3295, Durham, NC 27710 USA.
来源：INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS
摘要：Purpose: To evaluate the feasibility of a retrospective binning technique for 4-dimensional magnetic resonance imaging (4D-MRI) using body area (BA) as a respiratory surrogate.; Methods and Materials: Seven patients with hepatocellular carcinoma (4 of 7) or liver metastases (3 of 7) were enrolled in an institutional review board-approved prospective study. All patients were simulated with both computed tomography (CT) and MRI to acquire 3-dimensinal and 4D images for treatment planning. Multiple-slice multiple-phase cine-MR images were acquired in the axial plane for 4D-MRI reconstruction. Image acquisition time per slice was set to 10-15 seconds. Single-slice 2-dimensinal cine-MR images were also acquired across the center of the tumor in orthogonal planes. Tumor motion trajectories from 4D-MRI, cine-MRI, and 4D-CT were analyzed in the superior-inferior (SI), anterior-posterior (AP), and medial-lateral (ML) directions, respectively. Their correlation coefficients (CC) and differences in tumor motion amplitude were determined. Tumor-to-liver contrast-to-noise ratio (CNR) was measured and compared between 4D-CT, 4D-MRI, and conventional T2-weighted fast spin echo MRI.; Results: The means (+/- standard deviations) of CC comparing 4D-MRI with cine-MRI were 0.97 +/- 0.03, 0.97 +/- 0.02, and 0.99 +/- 0.04 in SI, AP, and ML directions, respectively. The mean differences were 0.61 +/- 0.17 mm, 0.32 +/- 0.17 mm, and 0.14 +/- 0.06 mm in SI, AP, and ML directions, respectively. The means of CC comparing 4D-MRI and 4D-CT were 0.95 +/- 0.02, 0.94 +/- 0.02, and 0.96 +/- 0.02 in SI, AP, and ML directions, respectively. The mean differences were 0.74 +/- 0.02 mm, 0.33 +/- 0.13 mm, and 0.18 +/- 0.07 mm in SI, AP, and ML directions, respectively. The mean tumor-to-tissue CNRs were 2.94 +/- 1.51, 19.44 +/- 14.63, and 39.47 +/- 20.81 in 4D-CT, 4D-MRI, and T2-weighted MRI, respectively.; Conclusions: The preliminary evaluation of our 4D-MRI technique results in oncologic patients demonstrates its potential usefulness to accurately measure tumor respiratory motion with improved tumor CNR compared with 4D-CT. (C) 2014 Elsevier Inc.