Sunday, 19 October 2014

High Powered MRI still misses things

Yao B, Hametner S, van Gelderen P, Merkle H, Chen C, Lassmann H, Duyn JH, Bagnato F 7 Tesla Magnetic Resonance Imaging to Detect Cortical Pathology in Multiple Sclerosis. PLoS One. 2014 Oct 10;9(10):e108863

BACKGROUND:Neocortical lesions (NLs) are an important pathological component of multiple sclerosis (MS), but their visualization by magnetic resonance imaging (MRI) remains challenging.
OBJECTIVES: We aimed at assessing the sensitivity of multi echo gradient echo (ME-GRE) T2*-weighted MRI at 7.0 Tesla in depicting NLs compared to myelin and iron staining.
METHODS: Samples from two MS patients were imaged post mortem using a whole body 7T MRI scanner with a 24-channel receive-only array. Isotropic 200 micron resolution images with varying T2* weighting were reconstructed from the ME-GRE data and converted into R2* maps. Immunohistochemical staining for myelin (proteolipid protein, PLP) and diaminobenzidine-enhanced Turnbull blue staining for iron were performed.
RESULTS: Prospective and retrospective sensitivities of MRI for the detection of NLs were 48% and 67% respectively. We observed MRI maps detecting only a small portion of 20 subpial NLs extending over large cortical areas on PLP stainings. No MRI signal changes suggestive of iron accumulation in NLs were observed. Conversely, R2* maps indicated iron loss in NLs, which was confirmed by histological quantification.
CONCLUSIONS: High-resolution post mortem imaging using R2* and magnitude maps permits detection of focal NLs. However, disclosing extensive subpial demyelination with MRI remains challenging.
Most clinical MRI scanners are about 1.5 tesla....maybe 3T is you push it. There are now high power scanners and in the UK high power MS Scanners are found in Nottingham and Oxford. However it is not high power enough and still misses a lot that conventional histology staining can see.This was even the case when this is done after death and so MRI in the living breathing person is even more difficult. Cortical damage is difficult to see even with 7 tesla

1 comment:

  1. High resolution scanners may be good, but if the Doctors and Techs involved do not know how to read them, when they write a report, they do no good.
    Mine was read and report written. Bold Print was "no sign of Multiple Sclerosis"
    The same film, and disc were taken to my neurologist, who saw and showed me the spots after a spinal tap, and blood test to rule out everything else. Definite Multiple Sclerosis.
    So moral is the better scanners, still need good doctors that can interpret the scans

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