View source: R/preprocessing.R
preprocess_modality_t1 | R Documentation |
This function preprocesses a raw T1-w MRI scan and generates a segmentation MRI scan using the FAST algorithm. The preprocesising steps comprises imhomogeneity correction 'N4', registration to the MNI152 template with isotropic voxel size of 1mm^3 using the 'SyN' transformation, and skull stripping.
preprocess_modality_t1( mri.patient, folder.patient, atlas, mask, inhomogeneity = "N4", transformation = "SyN" )
mri.patient |
path of the T1-weighted scan. |
folder.patient |
folder containing the T1-weighted scan. This folder usually refers to the patient. |
atlas |
atlas template in NifTI format to spatially register the T1-weighted scans. By default the MNI152 atlas template is used. |
mask |
brain mask in NifTI format of the atlas template to performed the skull stripping. |
inhomogeneity |
inhomogeneity correction algorithm to be applied. The correction by default is the 'N4' bias correction. |
transformation |
non-linear transformation for registering the T1-w MRI scan to the reference template. 'SyN' transformation is used by default. |
paths of preprocessed MRI scans.
David Payares
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Yongyue Zhang, J. Michael Brady, Stephen Smith Hidden Markov random field model for segmentation of brain MR image. Medical Imaging 2000: Image Processing, 2000.
Jean-Philippe Fortin, Elizabeth M Sweeney, John Muschelli, Ciprian M Crainiceanu, Russell T Shinohara, Alzheimer’s Disease Neuroimaging Initiative, et al. Removing inter-subject technical variability in magnetic resonance imaging studies. NeuroImage, 132:198–212, 2016.
## Not run: # Get general folder folder <- system.file("extdata", package = "neurodata") # Get covariates covariates <- system.file("covariates.txt", package = "neurodata") # Read covariates information clinical_info <- read.csv(file = covariates, sep = ';') # Folder and T1-weighted file of the patient patient_folder <- file.path(folder,"patient01") patient_T1 <- file.path(patient_folder,"patient01_T1.nii.gz") # Getting preferred atlas template and template mask # Using the MNI152 template available in the MNITemplate package library(MNITemplate) atlas <- getMNIPath() atlas_mask <- readMNI("Brain_Mask") # Preprocessing the patient's sequences patient_preprocessed_mri <- preprocess_modality_t1(mri.patient = patient_T1, folder.patient = patient_folder, atlas = atlas, mask = atlas_mask, inhomogeneity = 'N4', transformation = 'SyN') ## End(Not run)
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