1naresh<pre>Array
(
    [urn:ac.highwire.org:guest:identity] => Array
        (
            [runtime-id] => urn:ac.highwire.org:guest:identity
            [type] => guest
            [service-id] => ajnr-ac.highwire.org
            [access-type] => Controlled
            [privilege] => Array
                (
                    [urn:ac.highwire.org:guest:privilege] => Array
                        (
                            [runtime-id] => urn:ac.highwire.org:guest:privilege
                            [type] => privilege-set
                            [privilege-set] => GUEST
                        )

                )

            [credentials] => Array
                (
                    [method] => guest
                )

        )

)
1naresh<pre>Array
(
    [urn:ac.highwire.org:guest:identity] => Array
        (
            [runtime-id] => urn:ac.highwire.org:guest:identity
            [type] => guest
            [service-id] => ajnr-ac.highwire.org
            [access-type] => FreeToRead
            [privilege] => Array
                (
                    [urn:ac.highwire.org:guest:privilege] => Array
                        (
                            [runtime-id] => urn:ac.highwire.org:guest:privilege
                            [type] => privilege-set
                            [privilege-set] => GUEST
                        )

                )

            [credentials] => Array
                (
                    [method] => guest
                )

        )

)
PT  - JOURNAL ARTICLE
AU  - van den Bogaard, S.J.A.
AU  - Dumas, E.M.
AU  - Hart, E.P.
AU  - Milles, J.
AU  - Reilmann, R.
AU  - Stout, J.C.
AU  - Craufurd, D.
AU  - Gibbard, C.R.
AU  - Tabrizi, S.J.
AU  - van Buchem, M.A.
AU  - van der Grond, J.
AU  - Roos, R.A.C.
TI  - Magnetization Transfer Imaging in Premanifest and Manifest Huntington Disease: A 2-Year Follow-Up
AID  - 10.3174/ajnr.A3303
DP  - 2012 Aug 23
TA  - American Journal of Neuroradiology
4099  - http://www.ajnr.org/content/early/2012/08/23/ajnr.A3303.short
4100  - http://www.ajnr.org/content/early/2012/08/23/ajnr.A3303.full
AB  - BACKGROUND AND PURPOSE: MTI is a quantitative MR imaging technique that has recently demonstrated structural integrity differences between controls and patients with HD. Potentially, MTI can be used as a biomarker for monitoring disease progression. To establish the value of MTI as a biomarker, we aimed to examine the change in these measures during the course of HD. MATERIALS AND METHODS: From the Leiden TRACK-HD study, 25 controls, 21 premanifest gene carriers, and 21 patients with manifest HD participated at baseline and during a 2-year follow-up visit. Brain segmentation of the cortical gray matter, white matter, caudate nucleus, putamen, pallidum, thalamus, amygdala, and hippocampus was performed by using the automated tools FAST and FIRST in FSL. Individual MTR values were calculated from these regions, and MTR histograms were constructed. RESULTS: In the premanifest HD group stage “far from disease onset,” a significant increase in MTR peak height of the putamen was observed with time. During the manifest HD stage, neither the mean MTR nor the MTR peak height showed a significant change during a 2-year follow-up. CONCLUSIONS: MTI-derived measures are not suitable for monitoring in Huntington disease during a 2-year period because there was no decrease in structural integrity detected in any of the manifest HD groups longitudinally. The finding of increased putaminal MTR peak height in the premanifest far from disease onset group could relate to a predegenerative process, compensatory mechanisms, or aberrant development but should be interpreted with caution until future studies confirm this finding. Abbreviations HDHuntington diseaseHD 1manifest HD stage 1HD 2manifest HD stage 2MTImagnetization transfer imagingMTRmagnetization-transfer ratio