Letters to the Editor MR Imaging , CT Scan , and Clinical Examination in Multiple Sclerosis

  • JeHrey Tobias Kalevi Soila
  • Published 2014

Abstract

I read with interest the paper by Sheldon et al. [1] comparing MR imaging, clinical , and CT examination in 74 patients affected by multiple sclerosis (MS). Their conclusion that MR is more sensitive than CT in detecting lesions in MS is questionable. In fact , these authors found MR positive in 85% of patients with definite MS, which is the same percentage found by Barrett et al. [2] in a high-resolution CT study. Furthermore, MR should not be compared with routinely infused CT scan, but with CT scan enhanced with the double-delayed high-dose (DOH D) technique [3]. The DDHD enhanced CT scan is the most sensitive technique for detecting MS plaques, especially in the exacerbation phases [4]. Sears et al. [4] , using the DDHD method , found 36 new lesions in eight patients with MS with an average number of four additional lesions in each case. The authors have suggested that enhanced CT lesions in MS are due to vasoactive plaques with disruption of the blood brain barrier. In a group of patients with definite MS and recent clinical exacerbation, Barrett et al. [2] found abnormal enhancement in 89% of the cases . Therefore, in clinical exacerbations, the CT scan seems to be more sensitive than MR in detecting active lesions. However, it is doubtful that current MR can distinguish between vasoactive and vasoinactive MS plaques and furnish information about the phase of the disease. Also, when comparing the two techniques , the effect of steroid therapy on contrast-enhancing CT scan lesions in MS must be considered. It has been reported that steroid treatment, especially with high-dose IV administration, markedly reduces or eliminates the enhanced plaques [5]. Therefore, comparison between MR and CT scan is not correct in patients undergoing steroid treatment. Finally, both CT scan and MR have a high positive percentage only in patients with definite MS. In patients with possible or probable MS, the sensitivity of the two techniques is limited. Detection of plaques by CT or MR in patients with possible or probable MS cannot predict the evolution of this disease. In fact , cases of benign form or clinically silent MS have been discovered at autopsy [6-8]. Additional longitudinal studies are needed to establish whether cases of possible or 1101

Cite this paper

@inproceedings{Soila2014LettersTT, title={Letters to the Editor MR Imaging , CT Scan , and Clinical Examination in Multiple Sclerosis}, author={JeHrey Tobias Kalevi Soila}, year={2014} }