A problem we face when making the case for a list of essential medications to treat MS in resource-poor settings is the issue of MS misdiagnosis and the inability to monitor MS disease activity using MRI in these settings. MRI is an expensive innovation and a large number of countries simply don’t have enough MR scanners to go around. How can the small number of pwMS in these countries hijack the scanners for monitoring, when they are needed for diagnostic imaging? In addition, MRI is expensive and often has to be paid for privately. I remember in the early days of MRI this being the case in South Africa; i.e. all the scanners were in the private sector and we had to make a request on a case-by-case basis to get state-funded patients scanned.
|From: Cauley and Fielden. Tomography 2018 Dec;4(4):194-203.|
Multiple sclerosis (MS) is a progressive neurodegenerative disease, affecting 1 million Americans and 2.5 million people globally. Although the diagnosis is made clinically, imaging plays a major role in diagnosing and monitoring disease progression and treatment response. Magnetic resonance imaging (MRI) has proven sensitive in imaging MS lesions, but the characterization offered by routine clinical MRI remains qualitative and with discrepancies between imaging and clinical findings. We investigated the ability of digital analysis of non-contrast head computed tomography (CT) images to detect global brain changes of MS. All routine diagnostic head CTs obtained on patients with known MS obtained from 1 of 2 scan platforms from 6/1/2011 to 6/1/2015 were reviewed. Head CT images from 54 patients with MS met inclusion criteria. Head CT images were processed and histogram metrics were compared to age- and gender-matchedcontrol subjects from the same CT scanners during the same time interval. Histogram metrics were correlated with plaque burden as seen on MRI studies. Compared with control subjects, patients had increased total brain radiodensity (P < .0001), further characterized as an increased histogram modal radiodensity (P < .0001) with decrease in histogram skewness (P < .0001). Radiodensity decreased with increasing plaque burden. Similar findings were seen in the patients with only mild plaque burden subgroup. Radiodensity is a unique tissue metric that is not measured by other imaging techniques. Our study finds that brain radiodensity histogram metrics highly correlate with MS, even in cases with minimal plaque burden.