MAPER is a method for anatomically segmenting magnetic resonance images of the human brain. The following paper describes the procedure:
Heckemann, R. A., Keihaninejad, S., Aljabar, P., Rueckert, D., Hajnal, J. V., Hammers, A., May 2010. Improving intersubject image registration using tissue-class information benefits robustness and accuracy of multi-atlas based anatomical segmentation. NeuroImage 51 (1), 221-227. http://dx.doi.org/10.1016/j.neuroimage.2010.01.072
MAPER is based on earlier work on multi-atlas based segmentation:
Heckemann, R. A., Hajnal, J. V., Aljabar, P., Rueckert, D., Hammers, A., October 2006. Automatic anatomical brain MRI segmentation combining label propagation and decision fusion. NeuroImage 33 (1), 115-126. http://dx.doi.org/10.1016/j.neuroimage.2006.05.061
We generally use a database of 30 MRI brain atlases of young healthy adults, partially available for download from www.brain-development.org (Resources - Atlases - Adult). The segmentations into 83 regions have been carefully prepared using a detailed, validated protocol which is described in the following two papers:
Hammers A, Allom R, Koepp MJ, Free S., Myers R, Lemieux L, Mitchell TN, Brooks DJ, Duncan JS, Aug. 2003. Three-dimensional maximum probability atlas of the human brain, with particular reference to the temporal lobe. Hum. Brain Mapp. 19 (4), 224-247. http://dx.doi.org/10.1002/hbm.10123
Gousias IS, Rueckert D, Heckemann RA, et al., 2008, Automatic segmentation of brain MRIs of 2-year-olds into 83 regions of interest, Neuroimage, Vol:40, ISSN:1053-8119, Pages:672-684. http://dx.doi.org/10.1016/j.neuroimage.2007.11.034
We processed the 996 baseline and screening images of ADNI (Alzheimer's Disease Neuroimaging Initiative) with MAPER. A description of the data and volumetric analysis results appears in
Heckemann RA, Keihaninejad S, Aljabar P, Gray KR, Nielsen C, Rueckert D, Hajnal JV, Hammers A, Alzheimer's Disease Neuroimaging Initiative, 2011, Automatic morphometry in Alzheimer's disease and mild cognitive impairment., Neuroimage, Vol:56, 1053-8119, Pages:2024-2037 http://dx.doi.org/10.1016/j.neuroimage.2011.03.014
The segmentations of the ADNI images are freely available for research purposes at the ADNI download site. After signing up as an ADNI participant, go through "Advanced Search", select the "Post-Processed" radio button and enter "MAPER*" under "Series Description".
For this work, we used diffusion tensor imaging to identify parts of the thalamus that connect to different cortical regions.
Traynor C, Heckemann RA, Hammers A, et al., 2010, Reproducibility of thalamic segmentation based on probabilistic tractography., Neuroimage, Vol:52, 1053-8119, Pages:69-85. http://dx.doi.org/10.1016/j.neuroimage.2010.04.024
Gray KR, Aljabar P, Heckemann RA, Hammers A, Rueckert D, Alzheimer's Disease Neuroimaging Initiative , close, 2013, Random forest-based similarity measures for multi-modal classification of Alzheimer's disease., Neuroimage, Vol:65, 1053-8119 Pages:167-175. http://dx.doi.org/10.1016/j.neuroimage.2012.09.065
Gray KR, Wolz R, Heckemann RA, Aljabar P, Hammers A, Rueckert D, Alzheimer's Disease Neuroimaging Initiative, 2012, Multi-region analysis of longitudinal FDG-PET for the classification of Alzheimer's disease., Neuroimage, Vol:60, 1053-8119, Pages:221-229. http://dx.doi.org/10.1016/j.neuroimage.2011.12.071
This work is remarkable in that we found inflammatory activity long after the trauma event and remote from the injury site.
Ramlackhansingh AF, Brooks DJ, Greenwood RJ, Bose SK, Turkheimer FE, Kinnunen KM, Gentleman S, Heckemann RA, Gunanayagam K, Gelosa G, Sharp DJ, close, Inflammation after Trauma: Microglial Activation and Traumatic Brain Injury, Annals of Neurology, Vol:70, ISSN:0364-5134, Pages:374-383. http://dx.doi.org/10.1002/ana.22455
This is a special one in that we showed involvement of the substantia nigra in temporal lobe epilepsy, which has not been documented before..
Keihaninejad S, Heckemann RA, Gousias IS, Hajnal JV, Duncan JS, Aljabar P, Rueckert D, Hammers A, 2012, Classification and lateralization of temporal lobe epilepsies with and without hippocampal atrophy based on whole-brain automatic MRI segmentation., PLoS One, Vol:7, Pages:1932-6203. http://dx.doi.org/10.1371/journal.pone.0033096
A study of a rare genetic syndrome. First introduction of MAPER-based volumetric fingerprinting.
Cross JH, Arora R, Heckemann RA, Gunny R, Chong K, Carr L, Baldeweg T, Differ AM, Lench N, Varadkar S, Sirimanna T, Wassmer E, Hulton SA, Ognjanovic M, Ramesh V, Feather S, Kleta R, Hammers A, Bockenhauer D, 2013, Neurological features of epilepsy, ataxia, sensorineural deafness, tubulopathy syndrome. Dev Med Child Neurol, Vol:55, 0012-1622, Pages:846-856. http://dx.doi.org/10.1111/dmcn.12171
Here, we used MAPER segmentations to correct partial volume effect in opioid receptor PET.
McGinnity CJ, Shidahara M, Feldmann M, Keihaninejad S, Barros DAR, Gousias IS, Duncan JS, Brooks DJ, Heckemann RA, Turkheimer FE, Hammers A, Koepp MJ, 2013, Quantification of opioid receptor availability following spontaneous epileptic seizures: Correction of [C-11]diprenorphine PET data for the partial-volume effect. Neuroimage 79:72-80. doi: 10.1016/j.neuroimage.2013.04.015.
Regional analysis of PET enables anatomical location classification of tubers in the brain.
Rubi S, Costes N, Heckemann RA, Bouvard S, Hammers A, Marti Fuster B, Ostrowsky K, Montavont A, Jung J, Setoain X, Catenoix H, Hino K, Liger F, Le Bars D, Ryvlin P. Positron emission tomography with alpha-[11C]methyl-L-tryptophan in tuberous sclerosis complex-related epilepsy. Epilepsia. 2013 Dec;54(12):2143-50. doi: 10.1111/epi.12412.
In this work, we showed that amygdala atrophy characterizes early disease even better than hippocampal atrophy.
Klein-Koerkamp Y, Heckemann RA, Ramdeen KT, Moreaud O, Keignart S, Krainik A, Hammers A, Baciu M, Hot P; Alzheimer's Disease Neuroimaging Initiative. Amygdalar atrophy in early Alzheimer's disease. Curr Alzheimer Res. 2014 Mar;11(3):239-52. doi: 10.2174/1567205011666140131123653
For regions known to be involved in recognizing facial expressions of emotions, we made a surprise discovery: functional impairment is correlated with region size in early Alzheimer's. We had expected that recognition deficits would correlate with regional atrophy, but our results strongly indicate the opposite, at least in early disease.
Sapey-Triomphe LA, Heckemann RA, Boublay N, Dorey JM, Hénaff MA, Rouch I, Padovan C, Hammers A, Krolak-Salmon P; Alzheimer's Disease Neuroimaging Initiative. Neuroanatomical Correlates of Recognizing Face Expressions in Mild Stages of Alzheimer's Disease. PLoS One. 2015 Dec 16;10(12):e0143586. http://dx.doi.org/10.1371%2Fjournal.pone.0143586.
Extensive evaluation of quantification strategies for a new cannabinoid receptor tracer, including region-based analysis.
Riano Barros DA, McGinnity CJ, Rosso L, Heckemann RA, Howes OD, Brooks DJ, Duncan JS, Turkheimer FE, Koepp MJ, Hammers A. Test-retest reproducibility of cannabinoid-receptor type 1 availability quantified with the PET ligand [11C]MePPEP. Neuroimage. 2014 Aug 15;97:151-62. doi: 10.1016/j.neuroimage.2014.04.020.
Building on MAPER, Christian Ledig developed MALP-EM. Thanks to an advanced label fusion process, MALP-EM achieves superior results in images showing traumatic brain injury.
Ledig C, Heckemann RA, Hammers A, Lopez JC, Newcombe VF, Makropoulos A, Lötjönen J, Menon DK, Rueckert D. Robust whole-brain segmentation: application to traumatic brain injury. Med Image Anal. 2015 Apr;21(1):40-58. doi: 10.1016/j.media.2014.12.003
Several further projects that use MAPER are underway.
This page will be updated with instructions on how to reproduce MAPER at your site. In the meantime, please feel free to email me for help with atlas-based segmentation.
Email: rolf dot heckemann at medtechwest dot se
For a while, this page showed a faulty email address. If you tried to contact me unsuccessfully, please accept my apologies. The current address is verified.