Data
68,525 items of data are available, covering 63,749 participants.
Some values have special meanings defined by Data-Coding
1317.
Defined-instances run from 2 to 3, labelled using Instancing
2.
Units of measurement are Units.
| Maximum | -1010 |
| Decile 9 | -1042 |
| Decile 8 | -1042 |
| Decile 7 | -1042 |
| Decile 6 | -1042 |
| Median | -1042 |
| Decile 4 | -1042 |
| Decile 3 | -1042 |
| Decile 2 | -1042 |
| Decile 1 | -1093 |
| Minimum | -1221 |
|
|
- Mean = -1051.66
- Std.dev = 22.4388
- 225 items below graph minimum of -1144
|
2 Instances
Instance 2 : Imaging visit (2014+)
63,742 participants, 63,742 items
| Maximum | -1020 |
| Decile 9 | -1042 |
| Decile 8 | -1042 |
| Decile 7 | -1042 |
| Decile 6 | -1042 |
| Median | -1042 |
| Decile 4 | -1042 |
| Decile 3 | -1042 |
| Decile 2 | -1042 |
| Decile 1 | -1094 |
| Minimum | -1221 |
|
|
- Mean = -1052.3
- Std.dev = 23.0347
- 200 items below graph minimum of -1146
|
Instance 3 : First repeat imaging visit (2019+)
4,783 participants, 4,783 items
| Maximum | -1010 |
| Decile 9 | -1042 |
| Decile 8 | -1042 |
| Decile 7 | -1042 |
| Decile 6 | -1042 |
| Median | -1042 |
| Decile 4 | -1042 |
| Decile 3 | -1042 |
| Decile 2 | -1042 |
| Decile 1 | -1042 |
| Minimum | -1146 |
|
|
- Mean = -1043.18
- Std.dev = 8.06731
- 111 items below graph minimum of -1042.14
- 1 item above graph maximum of -1041.86
|
Notes
The exact location of the head and the radio-frequency receive coil in the scanner can affect data quality and imaging-derived phenotypes. To help account for variations in position in different scanned participants, several variables have been generated which describe aspects of the positioning and can be used as "confounding variables" - for example they might be regressed out of brain phenotypes before carrying out correlations between these and non-imaging variables.
The table position is the Z-co-ordinate of the coil (and the scanner table that the coil sits on) within the scanner. The Z axis points down the centre of the magnet.
Coding 1317 defines 1 special value:
- -999999 represents "Measure not cleanly recoverable from data"
1 Related Data-Field
| Field ID | Description | Relationship |
|---|
| 25758 | Scanner longitudinal (Z) brain position | Current Field is the table position used to measure longitudinal Field 25758 |
