Background and Purpose
There have been few neuroimaging studies of pediatric cerebral malaria (CM), a common, often fatal tropical condition. We undertook a prospective study of pediatric CM to better characterize the MRI features of this syndrome, comparing findings in children meeting a stringent definition of CM to those in a control group who were infected with malaria but who were likely to have a non-malarial cause of coma.
Materials and Methods
Consecutive children admitted with traditionally defined CM (parasitemia, coma and no other coma etiology evident) were eligible for this study. The presence or absence of malaria retinopathy was determined. MRI findings in patients with retinopathy-positive (ret+) CM (cases) were compared to those with retinopathy-negative (ret−) CM (controls). Two radiologists blinded to retinopathy status jointly developed a scoring procedure for image interpretation and provided independent reviews. MRI findings were compared between patients with and without retinopathy, to assess the specificity of changes for patients with very strictly defined CM.
Results
Of 152 children with clinically defined CM, 120 were ret+, and 32 were ret −. Abnormalities were much more common in the ret + cases, and included severe edema, abnormal T2 signal, and DWI abnormalities in the cortical, deep gray and white matter structures. Focal abnormalities rarely respected vascular distributions. Most of the scans in the more clinically heterogeneous ret− group were normal, and none of the abnormalities noted were more prevalent in controls.
Conclusions
Distinctive MRI findings present in patients meeting a stringent definition of CM may offer insights into disease pathogenesis and treatment.
By using a receiver operating characteristic approach and a standardized set of chest radiographs, observer accuracy and variability are easily quantified. This approach provides a basis for comparing the diagnostic performance of physicians. When value is measured as a diminution in uncertainty, board-certified radiologists contribute substantial value to the diagnostic imaging system.
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.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.