DICOM PS3.3 2021e - Information Object Definitions

C.34.9.2 Dose Related Attributes in Parameter Specification Sequence

If CTDIvol Notification Trigger (0018,9942) or DLP Notification Trigger (0018,9943) are present in a parameter specification for an Acquisition Protocol Element, each is intended to communicate a Dose Check (NEMA XR-25-2010) threshold value associated with that Acquisition Protocol Element. As such, a Constraint Type (0082,0032) of EQUAL would be the most appropriate.

If CTDIvol (0018,9345) is present in a parameter specification for an Acquisition Protocol Element, the value is intended to communicate an estimate of the CTDIvol for that Acquisition Protocol Element. It is expected that the value would either be a single CTDIvol that represents a typical value given the parameter constraints and defaults provided, or a range that represents the expected value range if the parameters are varied within the defined constraints. The value of CTDIvol is not itself a constraint on the execution of the Protocol, but rather an estimate to help the radiologist, technologist and/or physicist when reviewing and managing sets of Protocols. Constraints and associated behaviors are provided by the CTDIvol Notification Trigger, the DLP Notification Trigger and the NEMA XR-25 Dose Check standard.

Note

It should be recognized that the formulae and methods used by any given scanner model to estimate CTDIvol may evolve over time. When such changes occur, devices that generate CT Defined Procedure Protocol Instances, are advised to generate new Instances using the revised estimation methods.

DICOM PS3.3 2021e - Information Object Definitions