Description of the Table Columns
The LIDC nodule size table (List 1) is comprised of the following columns:
| Title | Contents |
| Subject | The digits after the last dot of the subject ID (the other part is constant and equal to 1.3.6.1.4.1.9328.50.3). |
| Study | The digits after the last dot of the Study Instance UID (the other part is constant and equal to 1.3.6.1.4.1.9328.50.3). |
| Roi | An arbitrary unique identifier for each physical nodule, estimated by at least one reader to be larger than 3 mm, in a study. |
| Volume |
The volume computed from the median of the equivalent diameter of the volume estimates for that
nodule. This is a slightly different method than what will be used
from List 2 onwards for the aggregation of multiple size estimates as
it refers to the context of the comparison of metrics1.
Each volume estimate is computed by multiplying the number of voxels
included in the nodule region by the voxel volume and the equivalent
diameter is equal to the diameter of a sphere having that volume. The units are mm3. |
| Eq. diam. | The equivalent diameter of the nodule, i. e. the diameter of the sphere having the same volume as the nodule estimated volume. The units of the diameter are mm. |
| X loc. | The x coordinate of the nodule location, computed as the median of the center-of-mass x coordinates, where x is an integer between 0 and 511 included and it increases from left to right. |
| Y loc. | The y coordinate of the nodule location, computed as the median value of the center-of-mass y coordinates, where y is an integer between 0 and 511 included and it increases from top to bottom. |
| Slice No. | The slice number of the nodule location, computed as the median value of the center-of-mass z coordinates, where the slice number is an integer starting at 1. |
| nodIDs | The identifier or identifiers of the nodule boundaries used for the volume estimation of that physical nodule. |
The data were downloaded around the end of 2006 (with an update in April 2009 for the subject ending in 0074) and all the subjects had their documentation processed.
- A. P. Reeves, A. M. Biancardi, T. V. Apanasovich, C. R. Meyer, H. MacMahon, E. J.R. van Beek, E. A. Kazerooni, D. Yankelevitz, M. F. McNitt-Gray, G. McLennan, S. G. Armato III, C. I. Henschke, D. R. Aberle, B. Y. Croft, and L. P. Clarke. "The lung image database consortium (LIDC): A comparison of different size metrics for pulmonary nodule measurements." Academic Radiology, 14(12):1475-1485, Dec 2007.