Function run_bet 

pub fn run_bet<F>(
    data: &[f64],
    grid: &Grid,
    params: &BetParams,
    progress: F,
) -> Vec<u8> 
where
    F: FnMut(usize, usize),

Run BET brain extraction

Arguments

• data - 3D magnitude image data (nx * ny * nz, Fortran order)
• grid - Volume grid (dimensions and voxel sizes)
• params - BET parameters (intensity threshold, smoothness, gradient, iterations, subdivisions)
• progress - Progress callback: (iteration, total_iterations)

Returns

Binary mask (1 = brain, 0 = background)