Sunday, 22 July 2018

Diagnosis: bigger is not always better

When you have a first demyelinating event, you get a scan to see if there are lesions in time (lesions of different age) and space (lesions in different places). 

Does it matter how big the scanner is?

The simple answer is no. 

The conventional scanner has a strenght of 1.5T (essentially showing how well the scanner can magnify the brain image)

Newer ones are 3T and are more powerful.

In a few places there are even 7T scanner.

With a 3T scanner you can see more lesions but it did not make a difference in the diagnosis if the scan was on 1.5T or 3T.

This is good as it suggests the post code lottery does not depend on the size of your scanner:-)


Hagens MHJ, Burggraaff J, Kilsdonk ID, de Vos ML, Cawley N, Sbardella E, Andelova M, Amann M, Lieb JM, Pantano P, Lissenberg-Witte BI, Killestein J, Oreja-Guevara C, Ciccarelli O, Gasperini C, Lukas C, Wattjes MP, Barkhof F; MAGNIMS Study Group.Three-Tesla MRI does not improve the diagnosis of multiple sclerosis: A multicenter study. Neurology. 2018 Jun 20. pii: 10.1212/WNL.0000000000005825.

OBJECTIVE: In the work-up of patients presenting with a clinically isolated syndrome (CIS), 3T MRI might offer a higher lesion detection than 1.5T, but it remains unclear whether this affects the fulfilment of the diagnostic criteria for multiple sclerosis (MS).
METHODS: We recruited 66 patients with CIS within 6 months from symptom onset and 26 healthy controls in 6 MS centres. All participants underwent 1.5T and 3T brain and spinal cord MRI at baseline according to local optimized protocols and the MAGNIMS guidelines. Patients who had not converted to MS during follow-up received repeat brain MRI at 3-6 months and 12-15 months. The number of lesions per anatomical region was scored by 3 raters in consensus. Criteria for dissemination in space (DIS) and dissemination in time (DIT) were determined according to the 2017 revisions of the McDonald criteria.
RESULTS: Three-Tesla MRI detected 15% more T2 brain lesions compared to 1.5T (p < 0.001), which was driven by an increase in baseline detection of periventricular (12%, p = 0.015), (juxta)cortical (21%, p = 0.005), and deep white matter lesions (21%, p < 0.001). The detection rate of spinal cord lesions and gadolinium-enhancing lesions did not differ between field strengths. Three-Tesla MRI did not lead to a higher number of patients fulfilling the criteria for DIS or DIT, or subsequent diagnosis of MS, at any of the 3 time points.
CONCLUSION: Scanning at 3T does not influence the diagnosis of MS according to McDonald diagnostic criteria.

5 comments:

  1. Isn’t the main reason for 3t to better see progression over time more carefully? I would think it would provide a higher degree of confidence on staying with the current dmt or switching.

    ReplyDelete
  2. Are there any prognosis signs from the first scan? Number of lesions, locations, etc?
    Can these predict the future course?

    I’ve read so much contradictory information, it’s tiring.
    Perhaps you can, or a colleague can, do a post on prognosis based on presentation.

    I know to newly diagnosed pwMS we often panic at the level of severity that we had at presentation.

    Gracias

    ReplyDelete
    Replies
    1. The more active the lesions, and lesion location can be prognostic at the population level but as I have said many times before the correlations of MRI and outcomes are generally so weak that at the individual level that are not predictive.

      Poor prognosis

      Male
      Age (Older)
      Multifocal onset
      Motor or cerebella affected
      High relapse rate
      Higher disability accumulation and poor recovery
      large lesion load,
      high activity
      other factors

      Delete

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