Friday, 11 March 2016

Hunting for grey matter lesions.

Kilsdonk ID, Jonkman LE, Klaver R, van Veluw SJ, Zwanenburg JJ, Kuijer JP, Pouwels PJ, Twisk JW, Wattjes MP, Luijten PR, Barkhof F, Geurts JJ. Increased cortical grey matter lesion detection in multiple sclerosis with 7 T MRI: a post-mortem verification study. Brain. 2016. pii: aww037. [Epub ahead of print]

The relevance of cortical grey matter pathology in multiple sclerosis has become increasingly recognized over the past decade. Unfortunately, a large part of cortical lesions remain undetected on magnetic resonance imaging using standard field strength. In vivo studies have shown improved detection by using higher magnetic field strengths up to 7 T. So far, a systematic histopathological verification of ultra-high field magnetic resonance imaging pulse sequences has been lacking. The aim of this study was to determine the sensitivity of 7 T versus 3 T magnetic resonance imaging pulse sequences for the detection of cortical multiple sclerosis lesions by directly comparing them to histopathology. We obtained hemispheric coronally cut brain sections of 19 patients with multiple sclerosis and four control subjects after rapid autopsy and formalin fixation, and scanned them using 3 T and 7 T magnetic resonance imaging systems. Pulse sequences included T1-weighted, T2-weighted, fluid attenuated inversion recovery, double inversion recovery and T2*. Cortical lesions (type I-IV) were scored on all sequences by an experienced rater blinded to histopathology and clinical data. Staining was performed with antibodies against proteolipid protein and scored by a second reader blinded to magnetic resonance imaging and clinical data. Subsequently, magnetic resonance imaging images were matched to histopathology and sensitivity of pulse sequences was calculated. Additionally, a second unblinded (retrospective) scoring of magnetic resonance images was performed. Regardless of pulse sequence, 7 T magnetic resonance imaging detected more cortical lesions than 3 T. Fluid attenuated inversion recovery (7 T) detected 225% more cortical lesions than 3 T fluid attenuated inversion recovery (Z = 2.22, P < 0.05) and 7 T T2* detected 200% more cortical lesions than 3 T T2* (Z = 2.05, P < 0.05). Sensitivity of 7 T magnetic resonance imaging was influenced by cortical lesion type: 100% for type I (T2), 11% for type II (FLAIR/T2), 32% for type III (T2*), and 68% for type IV (T2). We conclude that ultra-high field 7 T magnetic resonance imaging more than doubles detection of cortical multiple sclerosis lesions, compared to 3 T magnetic resonance imaging. Unfortunately, (subpial) cortical pathology remains more extensive than 7 T magnetic resonance imaging can reveal.

So lets all get a 7T scanner because they are better than 3T. 

In ths study they hunt for grey matter lesions and find more 200% more, so if they find one with 3T now they can find 3 with 7T,but it still misses loads. What next 11T for all:-)?


6 comments:

  1. will i levitate inside 11T coil?

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  2. on a tangent kind of, but would a 7T scanner make any difference in the detection of PML?

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  3. Does anyone know of any way to get time on a 7T machine? I have left a voicemail for a few folks at NYU but no one has got back to me. I understand that they are still kicking the tires on the machine and it is preclinical.

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