Title: CT Dose Reporting with DICOM Structured Report (SR)
1(No Transcript)
2CT Dose Reporting with DICOM Structured Report
(SR)
- A new supplement has been created based on the
request of IEC MT30 CT - The CT Dose Report, as defined in the supplement
is based on supplement 94 concerning X-Ray
radiation. - The requirements of the CT SR dose reporting were
presented on the RSNA and distributed in WG21
(see the following slides). - The Supplement was discussed by DICOM WG21 CT in
July and shall be released in the near future
(March of 2007).
3DICOM Structured Report Dose
- The Radiation Dose reporting shall be defined
through a DICOM Structured Report (SR) object
template and SOP Class. This SR object could be
routed to an appropriate Radiation Safety
Reporting System. A system that claims
conformance to such a SR object would then be
expected to appropriately deal with such data
items. - The proposal for CT Dose Reporting is derivated
from the Supplement 94 Diagnostic X-Ray
Radiation Dose Reporting (Dose SR)
4Irradiation Event and Structured Report
- An irradiation event is the occurrence of
radiation being applied to a patient in a single
continuous time-frame between the start (release)
and the stop (cease) of the irradiation. - A differentiation is made between dose relevant
data that has to be provided per event and
those data that represent accumulations. - Any on-off switching of the radiation source
during the event shall not be treated as separate
events, rather the event includes the time
between start and stop of radiation as triggered
by the user. E.g., a pulsed fluoro X-Ray
acquisition shall be treated as one single
irradiation event. - An amount of additional data to describe the
physical context and the quality of the
irradiation exposure has to be recorded along
with the dose values. - The irradiation event is the smallest
information entity to be recorded in the realm of
Radiation Dose reporting. Patient Information and
study information shall be stored with the DICOM
Dose SR object. - An event resulting in creation of a DICOM Image
SOP Instance or SOP series shall be included as a
reference.
5X-Ray SR Dose IOD Modules and Structure
IE Module Reference Description
Patient Patient C.7.1.1 Describes the identity of patient
Clinical Trial Subject C.7.1.3 Identify clinical trial subject
Study General Study C.7.2.1 Describes the study performed upon patient
Patient Study C.7.2.2 Describes information about study
Clinical Trial Study C.7.2.3 Identify context of clinical trial
Series SR Document Series C.17.1 Defines attributes of the SR document
Clinical Trial Series C.7.3.2 Identify context of clinical trial
Frame of Reference Synchronization C.7.4.2 Synchronization to patient study
Equipment General Equipment C.7.5.1 Attributes to identify the equipment
Document SR Document General C.17.2 General context of SR document
SR Document Content C.17.3 Specifies the attributes contained in the SR
SOP Common C.12.1 DICOM basic for definition of object
CT Accumulated Irradiation Dose Study template Accumulated irradiation for an entire examination
CT Irradiation Event template 1 to n separate irradiation events
6Summary of Accumulated Dose
- The report summary shall give an overview of the
whole patient examination and the accumulated
dose applied. - The patient information, the patient study
information and the general equipment information
is stored within the general part of the SR - The total DLP of a patient examination is
required. - The accumulated irradiation effective dose in mSv
may stated. This is optional! - The method of evaluation is stated
- The measuring devices are stated, if applicable
- The generation, the relationship and the dose of
each event are stated in separate sequences.
7Content of the CT Irradiation Event
- The clinical character of the examination shall
be stated - The type of acquisition shall be stated
- The relation to the DICOM study and image objects
shall be stated. - The relation to the patient region shall be given
by body part examined - The parameters of dose evaluation shall be given
- The parameters of the generation of the
irradiation and acquisition shall be stated. - The dose of a single event shall be stated.
8CT Acquisition Sequence
- The acquisition type is stated sequenced or
spiral. - Fluoroscopy flag is stated if applicable.
- A reference id (Radiation event UID) is stated to
identify related series and images within this
patient study.
9CT Acquisition Parameters
- The tube voltage and the tube current are stated.
- The effective exposure in mAs is stated.
- The exposure time and the scanning length are
stated. - Acquisition parameters related to the volume
acquisition are stated (collimation, pitch
factor).
10CT Irradiation Event Dose Summary
- A comment related to exam and dose can be
appended. - For each CT Acquisition (irradiation event)
- The CITDIvol and DPL are stated.
- The corresponding CTDIfreeair is stated.
- The effective dose may be stated, optional.
- The detection method and the parameters used are
stated. - The reference values for dose estimation and
calculation are stated, e.g. calibration factor,
effective dose type
11What happens
12History of Versions
01 May 31, 2006 Created, draft distributed 02
August 01, 2006 Correctives included FDA (S.
Stern), GE Healthcare (D. Littlejohn), Philips
(S. Gotman), Siemens (B. Hassold) 03 September
20, 2006 Correctives included Position of IEC/SC
62B Position of IEC/SC 62, GEHC Comments (D.
Littlejohn), Position of the 10th Meeting of the
Maintenance Team IEC/62B/MT30 04 October 20, 2006
Correctives included FDA (S. Stern), GE
Healthcare (D. Littlejohn, Harry Solomon), 05
January 08, 2007 Correctives included GE
Healthcare (D. Littlejohn, Harry Solomon), 06
January 25, 2007Correctives include WG
13Who was Involved
- IEC WG 30 Norbert Bischof, Stanley Stern,
Christoph Suess - FDA Stanley Stern,
- Nema Stephen Vastagh,
- DICOM Stephen Vastagh, WG21
- Response of Manufactures GE, Philips, Siemens