| DICOM PS3.17 2024d - Explanatory Information |
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This CT example describes a set of measurements (volume, long axis (RECIST), short axis (WHO bi-dimensional) and mean attenuation coefficient) made from a single volumetric ROI encoded as a single segment, including specification of the end points of the line segment used to make the linear distance measurements.
The lengths of the long axis and the short axis of the lesion are not encoded as characteristics of the volumetric ROI, but rather the long axis and the short axis are encoded explicitly as the end points of line segments used to make those measurements. The commonality of the Tracking Unique Identifier establishes that they are measurements of the same ROI. If multiple measurements were to be made of the same ROI over time or by different observers, other Content Items such as those related to Timepoint, Activity Session and Observer may be used. For an alternative encoding, see Section RRR.2.
The pattern of using multiple sibling linear distance measurements within TID 1419 “ROI Measurements” is similar to and not incompatible with the pattern used for length, width and height in the OB/GYN Ultrasound template TID 5016 “LWH Volume Group”.
The Finding Site information is duplicated in the second measurement template invocation in this example, though it is not required to be.
Table RRR.5-1. Volumetric ROI on CT Example
| DICOM PS3.17 2024d - Explanatory Information |
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