MRICloudMultidelayCalculateCBFATT
=================================

**Purpose.** Voxelwise fit of **CBF** and **ATT** from multi-delay ASL using MRICloud kinetic models (PCASL and PASL).

Inputs
------

- ``derivatives/<sub>/perf/{asl}.nii`` (4D)
- ``M0map.nii``, ``brnmsk_dspl.nii``, ``brnmsk_clcu.nii``
- ``ASLContext`` including ``label`` and ``control``
- PLDs per label volume (derived from ``PLDList``)

Outputs
-------

- ``{asl}_aCBF_native.nii`` — absolute CBF
- ``{asl}_rCBF_native.nii`` — relative CBF (normalized)
- ``{asl}_ATT_native.nii`` — arterial transit time (ms)

Configuration
-------------

=================  ===================  ==========================================
Key                Type / Default       Meaning
=================  ===================  ==========================================
``t1_blood``       int / ``1650``       Blood T1 (ms)
``part_coef``      float / ``0.9``      Partition coefficient (λ)
=================  ===================  ==========================================

YAML example
------------

.. code-block:: yaml

    modules:
      - name: MRICloudMultidelayCalculateCBFATT
        params:
          t1_blood: 1650
          part_coef: 0.9