IEC 62985-2019 pdf download.Methods for calculating size specific dose estimates (SSDE) on computed tomography (IEC 62985:2019).
This document applies to
– CT SCANNERS that are able to display and report CTDI VOL in accordance with
IEC 60601 -2-44, and
– RADIATION dose index monitoring software (RDIMS) for the purpose of calculating, displaying and recording the SIZE SPECIFIC DOSE ESTIMATE ( SSDE ) and its associated components.
Specifically, this document provides standardized methods and requirements for calculating, displaying, or recording of SSDE , SSDE (z), WATER EQUIVALENT DIAMETER (D W ), and D W (z), where z represents a specific longitudinal position of the scanned object. This document provides a method of determining a reference WATER EQUIVALENT DIAMETER , D W,REF (z), using CT scans of two cylindrical water PHANTOMS and one or more anthropomorphic PHANTOM ( S ), which conform to the specifications defined in this document. The method of calculating the WATER EQUIVALENT DIAMETER that is implemented by the MANUFACTURER , D W,IMP (z), is tested and validated against D W,REF (z) using the TEST OBJECTS and methods defined within this document. This document also describes the methods for calculating SSDE and D W, which represent the average values of SSDE (z) and D W (z) over the RECONSTRUCTION LENGTH .
NOTE This standardization is important to ensure that comparisons between reported SSDEs are valid.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
IEC TR 60788:2004, Medical electrical equipment – Glossary of defined terms
IEC 60601 -1 :2005, Medical electrical equipment – Part 1: General requirements for basic safety and essential performance
IEC 60601 -1 :2005/AMD1 :201 2
IEC 60601 -1 -3:2008, Medical electrical equipment – Part 1-3: General requirements for basic safety and essential performance – Collateral Standard: Radiation protection in diagnostic X- ray equipment
IEC 60601 -2-44:2009, Medical electrical equipment – Part 2-44: Particular requirements for the basic safety and essential performance of X-ray equipment for computed tomography
3 Terms and definitions
For the purposes of this document, the terms and definitions of IEC TR 60788, IEC 60601 -1 , IEC 60601 -1 -3, IEC 60601 -2-44, and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1 CTDI VOL AT LONGITUDINAL POSITION Z
CTDI VOL (z) value quantifying the RADIATION OUTPUT at position z for the selected CT CONDITIONS OF OPERATION
3.2 RECONSTRUCTION LENGTH
distance between the centre of the first reconstructed image and the centre of the last reconstructed image, where the centres of the first and last reconstructed images are spaced as far apart as possible given the CT CONDITIONS OF OPERATION for the PROTOCOL ELEMENT and the width of the reconstructed images, being essentially the maximum range of reconstructed images over the scan range for a given reconstruction section thickness.IEC 62985 pdf download.