Department of Radiology, College of Osteopathic Medicine, Michigan State University, East Lansing, MI 48824, USA.
J Digit Imaging. 2011 Aug;24(4):729-38. doi: 10.1007/s10278-010-9323-4.
As part of an NIH-funded study of malaria pathogenesis, a magnetic resonance (MR) imaging research facility was established in Blantyre, Malaŵi to enhance the clinical characterization of pediatric patients with cerebral malaria through application of neurological MR methods. The research program requires daily transmission of MR studies to Michigan State University (MSU) for clinical research interpretation and quantitative post-processing. An intercontinental satellite-based network was implemented for transmission of MR image data in Digital Imaging and Communications in Medicine (DICOM) format, research data collection, project communications, and remote systems administration. Satellite Internet service costs limited the bandwidth to symmetrical 384 kbit/s. DICOM routers deployed at both the Malaŵi MRI facility and MSU manage the end-to-end encrypted compressed data transmission. Network performance between DICOM routers was measured while transmitting both mixed clinical MR studies and synthetic studies. Effective network latency averaged 715 ms. Within a mix of clinical MR studies, the average transmission time for a 256 × 256 image was ~2.25 and ~6.25 s for a 512 × 512 image. Using synthetic studies of 1,000 duplicate images, the interquartile range for 256 × 256 images was [2.30, 2.36] s and [5.94, 6.05] s for 512 × 512 images. Transmission of clinical MRI studies between the DICOM routers averaged 9.35 images per minute, representing an effective channel utilization of ~137% of the 384-kbit/s satellite service as computed using uncompressed image file sizes (including the effects of image compression, protocol overhead, channel latency, etc.). Power unreliability was the primary cause of interrupted operations in the first year, including an outage exceeding 10 days.
作为美国国立卫生研究院（NIH）资助的疟疾发病机制研究的一部分，马拉维布兰太尔设立了一个磁共振（MR）成像研究机构，通过应用神经 MR 方法来增强对小儿脑疟疾患者的临床特征描述。该研究项目需要每天将 MR 研究传输到密歇根州立大学（MSU），以便进行临床研究解读和定量后处理。为了传输 MR 图像数据（以数字成像和通信在医学中的格式）、收集研究数据、进行项目通信和远程系统管理，建立了一个基于卫星的洲际网络。卫星互联网服务的成本限制了带宽至对称 384 kbit/s。在马拉维磁共振成像设施和 MSU 部署的 DICOM 路由器管理端到端加密压缩数据传输。在传输混合临床 MR 研究和合成研究时，测量了 DICOM 路由器之间的网络性能。有效网络延迟平均为 715 ms。在混合临床 MR 研究中，对于 256×256 图像，平均传输时间约为 2.25 s，对于 512×512 图像，平均传输时间约为 6.25 s。对于 1000 个重复图像的合成研究，256×256 图像的四分位间距为 [2.30, 2.36] s，512×512 图像的四分位间距为 [5.94, 6.05] s。DICOM 路由器之间传输临床 MRI 研究的平均速度为每分钟 9.35 张图像，这表示使用未压缩的图像文件大小（包括图像压缩、协议开销、信道延迟等的影响）计算出的 384 kbit/s 卫星服务的有效信道利用率约为 137%。在第一年中，电源不可靠是导致操作中断的主要原因，包括一次超过 10 天的停电。
