[ENH] Add coil entity for uncombined MR data

src/04-modality-specific-files/01-magnetic-resonance-imaging-data.md

@@ -24,6 +24,7 @@ by Ben Inglis:
          "RECOMMENDED",
          "See an example below the table.",
       ),
+      "CoilString": "RECOMMENDED",
       "GradientSetType": "RECOMMENDED",
       "MRTransmitCoilSequence": "RECOMMENDED",
       "MatrixCoilMode": "RECOMMENDED",
@@ -246,6 +247,12 @@ sequences using different contrast enhanced images. The label is the name of the
 contrast agent. The key `ContrastBolusIngredient` MAY be also be added in the
 JSON file, with the same label.
 
+The OPTIONAL [`coil-<label>`](../99-appendices/09-entities.md#coil) key/value can be used to distinguish coil-specific data.
+Typically it is used for sequences not employing coil combination (for example, SWI).
+When the file contains data from a single coil, `coil-<label>` SHOULD be provided.
+The key `CoilString` MAY also be added in the JSON file, with a corresponding
+identifier for the coil.
+
 Some meta information about the acquisition MAY be provided in an additional
 JSON file. See [Common metadata fields](#common-metadata-fields) for a
 list of terms and their definitions. There are also some OPTIONAL JSON
@@ -404,6 +411,11 @@ reconstruction algorithms (for example ones using motion correction).
 See [`fmap` Case 4](01-magnetic-resonance-imaging-data.md#case-4-multiple-phase-encoded-directions-pepolar)
 for more information on `dir` field specification.
 
+Similarly the OPTIONAL [`coil-<label>`](../99-appendices/09-entities.md#coil) key/value can be used to distinguish
+coil-specific data from sequences not employing coil combination.
+The key `CoilString` MAY also be added in the JSON file, with a corresponding
+coil identifier.
+
 Multi-echo data MUST be split into one file per echo using the
 [`echo-<index>`](../99-appendices/09-entities.md#echo) key-value pair. For example:
 

src/schema/datatypes/anat.yaml

@@ -25,6 +25,7 @@
     ceagent: optional
     reconstruction: optional
     part: optional
+    coil: optional
 # Parametric
 - suffixes:
     - T1map

src/schema/datatypes/func.yaml

@@ -19,6 +19,7 @@
     run: optional
     echo: optional
     part: optional
+    coil: optional
 # Phase (deprecated)
 - suffixes:
     - phase  # deprecated

src/schema/entities.yaml

@@ -177,6 +177,16 @@ part:
     When there is only a magnitude image of a given type, the `part` key MAY be
     omitted.
   format: label
+coil:
+  name: Coil
+  entity: coil
+  description: |
+    The `coil-<label>` key/value can be used to distinguish coil-specific data.
+    Typically it is used for sequences not employing coil combination (for example, SWI).
+    When the file contains data from a single coil, `coil-<label>` SHOULD be provided.
+    The key `CoilString` MAY also be added in the JSON file, with a
+    corresponding identifier for the coil.
+  format: label
 recording:
   name: Recording
   entity: recording