Mixed HEAD16 and BODY32 DLP values in same study, and how to report total (e.g. in RDSR)
David Clunie
Some scanners allow (DICOM) studies with multiple body parts scanned
(e.g., an adult head and a chest/abdomen/pelvis), and report DLP
values using the appropriately sized (i.e., different) phantom per
acquisition.
Then the question arises as to how a single "total DLP" value is
computed and reported, both in the dose screens and in the RDSR (which
currently allows for only a single total).
I have been working on a DICOM CP for RDSR for this (to allow for
separate per-phantom sub-totals and to report for which phantom the
single total is computed) and discussing it in DICOM WG 21 where the
CT modality vendors hang out, but I wanted to hear from users and 3rd
party producers of RDSRs and consumers of RDSR what their experience
has been with the installed base.
Specifically, I would be interested to know what each of the vendors'
systems currently
do in this respect, e.g,:
- issue 2 separate reports
- allow & report mixed per event phantoms and
- send a total value ignoring the issue
- send a total value that "corrects" for the problem
- always report one phantom even if a body part/FOV would report with
a different phantom if scanned by itself
From the registry (e.g., ACR DIR) perspective, I would imagine that
this would significantly affect the reported numbers for sites that
followed this practice if not specifically accounted for.
See:
"http://idisk.mac.com/dclunie-Public/Dose/
cp_dac175_RDSRHeadBodyTotalDLP2.doc"
and for a sample dose screen from a real case and a crude prototype
RDSR see:
"http://idisk.mac.com/dclunie-Public/Dose/
CleanedHeadAndBodyExampleScreenAndSR20111206.zip"
David