processROIs: Process ROI Voxel Data from a NIfTI File

Description

Processes Regions of Interest (ROIs) from a binary NIfTI file by extracting voxel-level coordinates and labeling each voxel as part of the ROI or not. The function preserves the spatial structure and is typically used to prepare ground truth ROIs for comparison with SCC-detected regions via calculateMetrics.

Usage

processROIs(
  roiFile,
  region,
  number,
  save = TRUE,
  outputDir = tempdir(),
  verbose = TRUE
)

Value

A data frame with voxel-level ROI information.

group – Combined identifier built from region and number.
z, x, y – Voxel coordinates.
pet – Binary value indicating ROI membership (1 = ROI, 0 = non-ROI).

If save = TRUE, the data frame is saved as an .RDS file and not returned to the console.

Arguments

roiFile: character. Path to the binary NIfTI file containing ROI data.
region: character. Name of the ROI region (e.g., "Region2").
number: character. Identifier for the subject or group (e.g., "18").
save: logical. If TRUE, saves the result as an .RDS file. If FALSE, returns a data frame in the console. Default is TRUE.
outputDir: character. Directory where the ROI table will be saved if save = TRUE. Default is a temporary file: tempdir().
verbose: logical. If TRUE, displays progress messages. Default is TRUE.

Details

The function uses neuroCleaner to load and flatten the NIfTI file into a structured data frame. All voxels are retained, with the pet column indicating which ones are part of the ROI (1) versus background (0). An ROI label is added in the group column.

This output is used as ground truth for evaluating detection performance in SCC analyses.

Examples

Run this code

# Load and process a sample ROI NIfTI file (console output)