Li Shuo, Sun Fei, Jin Zheng-Yu, Xue Hua-Dan, Li Ming-Li
Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
J Magn Reson Imaging. 2007 Oct;26(4):1139-44. doi: 10.1002/jmri.21074.
To optimize the free-breathing whole-body diffusion-weighted imaging (WB-DWI) protocol by using the short TI inversion-recovery diffusion-weighted echo-planar imaging (STIR-DWEPI) sequence and the built-in body coil. Additionally, to evaluate the feasibility of tumor screening using high-resolution three-dimensional (3D) maximum intensity projection (MIP) images.
The prescan procedure of STIR-DWEPI was modified using the data from 30 volunteers. During each exam, an optimized center frequency (CF) was used to minimize the slice offsets in consecutive scan stations. Prescan time was reduced from 50 seconds to 20 seconds with improved station profile. Total scan time was 30 minutes for five stations and 1.2 m coverage. A total of 30 patients with histologically-proven malignant disease were scanned under the final protocol using a built-in body coil. The image quality and the degree of background body signal suppression were assessed.
Free-breathing WB-DWI was 100% successfully performed in all patients, without slice misregistration, fat contamination, significant distortion, or nonuniformity. The reconstructed 3D-MIP images were adequate to depict malignant lesions in all 30 patients. The results of WB-DWI were found to be comparable to those of single-photon emission computed tomography (SPECT) and positron emission tomography (PET).
Stable and high-resolution WB-DWI is feasible using the technical improvements described in this study. WB-DWI might have important clinical value for the detection of primary and metastatic malignancies within the whole body. The potential for diagnosis and therapeutic assessment of tumors should be further assessed in a larger patient cohort.
通过使用短TI反转恢复扩散加权回波平面成像（STIR-DWEPI）序列和内置体线圈来优化自由呼吸全身扩散加权成像（WB-DWI）协议。此外，评估使用高分辨率三维（3D）最大强度投影（MIP）图像进行肿瘤筛查的可行性。
利用30名志愿者的数据修改了STIR-DWEPI的预扫描程序。在每次检查期间，使用优化的中心频率（CF）来最小化连续扫描部位的切片偏移。预扫描时间从50秒减少到20秒，同时改善了部位轮廓。五个部位的总扫描时间为30分钟，覆盖范围为1.2米。使用内置体线圈按照最终协议对30例经组织学证实为恶性疾病的患者进行了扫描。评估了图像质量和背景身体信号抑制程度。
所有患者均100%成功完成自由呼吸WB-DWI，无切片配准错误、脂肪污染、明显变形或不均匀性。重建的3D-MIP图像足以描绘所有30例患者的恶性病变。发现WB-DWI的结果与单光子发射计算机断层扫描（SPECT）和正电子发射断层扫描（PET）的结果相当。
使用本研究中描述的技术改进，稳定且高分辨率的WB-DWI是可行的。WB-DWI可能对全身原发性和转移性恶性肿瘤的检测具有重要临床价值。肿瘤的诊断和治疗评估潜力应在更大的患者队列中进一步评估。
