add table for volume timing

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

@@ -269,6 +269,22 @@ combined image rather than an image from each coil.
 | AcquisitionDuration               | RECOMMENDED. Duration (in seconds) of volume acquisition. Corresponds to DICOM Tag 0018,9073 `Acquisition Duration`. This field is REQUIRED for sequences that are described with the `VolumeTiming` field and that not have the `SliceTiming` field set to allowed for accurate calculation of "acquisition time". This field is mutually exclusive with `RepetitionTime`.                                                                                                                                                                                                                              |
 | DelayAfterTrigger                 | RECOMMENDED. Duration (in seconds) from trigger delivery to scan onset. This delay is commonly caused by adjustments and loading times. This specification is entirely independent of `NumberOfVolumesDiscardedByScanner` or `NumberOfVolumesDiscardedByUser`, as the delay precedes the acquisition.                                                                                                                                                                                                                                                                                                    |
 
+The following table recapitulates the different ways that specific fields have to be populated for functional sequences.
+
+|                   | RepetitionTime | SliceTiming | AcquisitionDuration | DelayTime | VolumeTiming |
+|-------------------|:--------------:|:-------------:|:---------------------:|:-----------:|:--------------:|
+| option 1          |       [X]      |             |         [ ]         |           |      [ ]     |
+| option 2          |       [ ]      |     [X]     |                     |    [ ]    |      [X]     |
+| option 3          |       [ ]      |             |         [X]         |    [ ]    |      [X]     |
+| sparse sequence 1 |       [X]      |     [X]     |         [ ]         |           |      [ ]     |
+| sparse sequence 1 |       [X]      |     [X]     |         [ ]         |    [X]    |      [ ]     |
+| sparse sequence 1 |       [X]      |             |         [ ]         |    [X]    |      [ ]     |
+
+**Legend**
+[X] --> has to be filled
+[ ] --> has to be left empty
+empty cell --> can be specified but not required
+
 ##### fMRI task information
 
 | Field name      | Definition                                                                                                                                                                                                 |