Journal of Clinical Neuroscience 17 (2010) 1482

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Journal of Clinical Neuroscience

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Commentary

Commentary: The past, present and future of imaging in multiple sclerosis

Anthony Kam *

Department of Medical Imaging and Radiation Sciences, Monash University, Clayton Campus, Clayton, Victoria, AustraliaMagnetic Resonance Imaging, Alfred Health, P.O. Box 315, Prahran, Victoria 3181, Australia

The review by Ramli et al. in a recent issue of the Journal ofClinical Neuroscience provides a short general overview of the past,present and future of imaging in multiple sclerosis (MS).1 Thenature of such a review is by no means exhaustive, but rather helpsgive an insight into ongoing developments in MS imaging. Thearticle will be of interest to individuals involved in the clinicalmanagement MS patients, as well as individuals interested in pur-suing MS-related research.

The introduction of MRI to the assessment of patients with mul-tiple sclerosis (MS) has dramatically altered our understanding ofthis most complex disease. Due to its superior sensitivity, MRIhas become an established clinical tool not only in the diagnosisof MS, but also to monitor its natural course and response toimmunomodulatory treatment.

Conventional MRI techniques such as T2 lesion load, gadoliniumenhancement, T1 hypointensity, and spatial and temporal diseasedissemination assessment have long become established in every-day clinical MS imaging. Due to the many MS mimickers seen onclinical imaging, however, researchers are constantly striving toensure that any proposed diagnostic criteria have a high specificitywithout sacrificing sensitivity.

Since the commonly used 2001 McDonald criteria,2 changeshave been towards simplifying the diagnostic criteria so that theybecome easier to use.3–5 Further simplification in terms of dissem-ination in time and space has been proposed, while being moresensitive than the 2001 and 2005 McDonald criteria without sacri-ficing specificity.6,7

It is well known that lesions detectable on conventional MRItechniques may only weakly correlate with the patient’s clinicalstatus.8 One explanation for such clinical–radiologic discrepancyis the lack of specificity of T2-weighted MRI, which discriminatesbetween focal MS lesions and normal-appearing white matterbut not between the underlying pathologic entities (oedema,demyelination, remyelination, gliosis and axonal loss) that contrib-ute differently to clinical symptoms.9 As such, tremendous effortsare being devoted to new uses of conventional imaging as wellas non-conventional advanced imaging techniques in an attemptto overcome such limitation.

Novel post-processing techniques employed in clinical trialshave incorporated cerebral volume measurements using conven-

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* Tel.: +61 3 9905 4000, +61 3 9905 4007.E-mail address: a.kam@alfred.org.au

tional MRI datasets.10,11 Advancements in non-conventional MRIapplications have also provided some interesting new tools in MSresearch. The use of techniques such as high field MRI, diffusiontensor imaging, tractography, magnetization transfer imaging,magnetic resonance spectroscopy, perfusion MRI and iron oxidemacrophage imaging have improved our ability to diagnose thedisease as well as our understanding of MS pathophysiology. As aresult of such efforts, new concepts that have emerged includeassessment of normal-appearing white matter, and detection ofgrey matter lesions. These techniques will need to be further re-fined, validated and standardised before they are integrated intoimaging protocols, diagnostic criteria and everyday clinical MSimaging.

References

1. Ramli N, Rahmat K, Azmi K, et al. The past, present and future of imaging inmultiple sclerosis. J Clin Neurosci 2010;17:422–7.

2. McDonald WI, Compston A, Edan G, et al. Recommended diagnostic criteria formultiple sclerosis: guidelines from the International Panel on the diagnosis ofmultiple sclerosis. Ann Neurol 2001;50:121–7.

3. Dalton CM, Brex PA, Miszkiel KA, et al. New T2 lesions enable an earlierdiagnosis of multiple sclerosis in clinically isolated syndromes. Ann Neurol2003;53:673–6.

4. Polman CH, Reingold SC, Edan G, et al. Diagnostic criteria for multiple sclerosis:2005 revisions to the ‘‘McDonald Criteria”. Ann Neurol 2005;58:840–6.

5. Tintoré M, Rovira A, Rio J, et al. New diagnostic criteria for multiple sclerosis:application in first demyelinating episode. Neurology 2003;60:27–30.

6. Swanton JK, Fernando K, Dalton CM, et al. Modification of MRI criteria formultiple sclerosis in patients with clinically isolated syndromes. J NeurolNeurosurg Psychiatry 2006;77:830–3.

7. Swanton JK, Rovira A, Tintoré M, et al. MRI criteria for multiple sclerosis inpatients presenting with clinically isolated syndromes: a multicentreretrospective study. Lancet Neurol 2007;6:677–86.

8. Miller DH, Thompson AJ, Filippi M, et al. Magnetic resonance studies ofabnormalities in the normal appearing white matter and grey matter inmultiple sclerosis. J Neurol 2003;250:1407–19.

9. Barkhof F, Bruck W, De Groot CJ, et al. Remyelinated lesions in multiplesclerosis: magnetic resonance image appearance. Arch Neurol 2003;60:1073–81.

10. Bermel RA, Bakshi R. The measurement and clinical relevance of brain atrophyin multiple sclerosis. Lancet Neurol 2006;5:158–70.

11. Prinster A, Quarantelli M, Orefice G, et al. Grey matter loss in relapsing-remitting multiple sclerosis: a voxel-based morphometry study. Neuroimage2006;29:859–67.