A new old technology

There is nothing more exciting than a new, but old, technology!


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. 

With this backdrop, I find the study below very illuminating. They simply analysed CT scans using histogram analysis, which was able to identify pwMS from appropriate controls. Why is this important? CT scanning is widely available, even in resource-poor settings, so being able to use CT to aid in the diagnosis of MS would address at least one of the concerns of our MS Essential Medicines List critics. The question would be logistics, i.e. how easy would it be to implement this sort of analysis in these environments? Maybe it could be done in the cloud using AI tools? Most medical centres, even in resource-poor countries, are now web-enabled. They could simply upload the data and get back a report on the likelihood of the patient having MS. 
Please note the reason for doing neuroimaging in the work-up for someone with possible MS is to exclude possible MS mimics. A CT scan goes a long way in doing just this. If you then get back a histogram analysis that makes MS likely, combining this with CSF analysis and other tests you may be able to get the necessary sensitivity and specificity for the diagnosis of MS in these settings. In fact, the ROC (receiver operating curve) analysis in this paper suggests the sensitivity and specificity of the histogram analysis technique are high enough to make this a viable option. 
All we need now is an MSologist or neurologist working in a resource-poor setting to take-up the challenge and to test whether or not CT-scanning can be used instead of MRI to make the diagnose of MS. This could transform the diagnostic work-up of people with possible MS in these environments.
There is nothing more exciting than a new, but old, technology; i.e. adapting an old technology to address an unmet need in the now. 
From: Cauley and Fielden. Tomography 2018 Dec;4(4):194-203.
Cauley and Fielden. A Radiodensity Histogram Study of the Brain in Multiple Sclerosis. 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.

CoI: none

5 thoughts on “A new old technology”

    1. Given way to the WHO essential medicines….frankly I do not understand why copaxone made it and generic cladribine didn't…A song by Dizzy Rascal springs to mind:-)

    2. Dealing with all the relevant stakeholders and the WHO is a delegate balancing act. I think we have come up with a good compromise. The important thing is that the list is not set in stone and can change with time.

    3. Re: ".. essential off-label DMT list …"It is still alive and kicking. The problem is getting people to adopt the list and use it locally, particularly in resource-poor settings.

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