ISO/IEC 3532-1:2023

INTERNATIONAL ISO/IEC
STANDARD 3532-1
First edition
2023-06
Information technology — Medical
image-based modelling for 3D
printing —
Part 1:
General requirements
Technologies de l'information — Modélisation médicale à base
d'images pour l'impression 3D —
Partie 1: Exigences générales
Reference number
© ISO/IEC 2023
© ISO/IEC 2023
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© ISO/IEC 2023 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms, definitions and abbreviated terms . 1
3.1 Terms and definitions . 1
3.2 Abbreviated terms . 4
4 Overview of image processing for the medical industry . 5
4.1 Process flow . 5
4.1.1 3D printing process for medical applications . 5
4.1.2 Explanation of a typical use case (cranial implant case) . 5
5 General requirements . 6
6 Requirements of data processing .7
6.1 Medical image data flow . 7
6.2 Medical image acquisition/computed tomography scan . 8
6.3 Segmentation . 9
6.4 3D reconstruction and visualization . 11
6.5 Calibration and validation of 2D and 3D conversion .12
6.6 File format . 13
Annex A (informative) Reporting .14
Bibliography .15
iii
© ISO/IEC 2023 – All rights reserved

Foreword
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The procedures used to develop this document and those intended for its further maintenance
are described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria
needed for the different types of document should be noted. This document was drafted in
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Attention is drawn to the possibility that some of the elements of this document may be the subject
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This document was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology.
A list of all parts in the ISO/IEC 3532 series can be found on the ISO and IEC websites.
Any feedback or questions on this document should be directed to the user’s national standards
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© ISO/IEC 2023 – All rights reserved

Introduction
This document was developed in response to the need for customization of 3D scanning and 3D printing
technology within the medical industry, which can be achieved by taking full advantage of information
and communication technology (ICT).
This document addresses the overview of medical image processing and requirements for image-
based modelling. 3D printing technology has caused a revolution in health care delivery. New classes
of medical devices embody the true meaning of personalized medicine. Medical device designers and
practitioners are able to practically and efficiently create devices that were very difficult or impossible
to create before. In addition to using 3D printing technology to create standard medical devices with
features like intricate lattice structures, clinicians and engineers work in conjunction to produce what
are known as patient-specific devices or patient-matched devices. These are medical devices designed
to fit a specific patient’s anatomy, typically using medical imaging from that patient. Anatomically
matched devices have very complex geometrical contours and shapes. Several challenges exist in the
design process between the input data and the final device design. Most of these steps definitely depend
on software-based management of medical images.
Overall, the world revenue from 3D printing technology in the healthcare industry is expected to grow
exponentially, yet very few guides exist for 3D printing for medical practice. Medical images from the
human body are different from solid objects due to the non-geometric nature of the human body. To
perform 3D printing for medical practice, an accurate and consistent approach for image processing and
data creation from medical images is needed. Standardization for 3D printing processes in medicine
is urgently required for education, diagnosis, neurosurgical treatment, developing simulation models,
medical equipment (including surgical guides) and surgical implantable devices in the clinical fields.
Regulatory bodies from several countries (US, Republic of Korea, etc.) have already published their
own guidelines for approval. However, those guidelines are not specifically designed for 3D printing
technology.
Applications of 3D printing in medicine are thriving, and include surgical simulation models, surgical
guides, educational models, surgical implants, etc. Those which are manufactured by 3D printing
technology require patient- and/or procedure-specific data (e.g. planned surgical technique and others)
and medical image data acquisition processing. Most of the processing of medical images for 3D printing
medical devices is software-based. In order to accurately and consistently visualize human body
anatomy, appropriate software-based modelling for 3D printing is needed. This document provides
requirements for software-based medical image processing for the purpose of producing 3D models for
3D printing. Valuable information related to optimized medical image data for additive manufacturing
can be found in ISO/ASTM TR 52916.
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© ISO/IEC 2023 – All rights reserved

INTERNATIONAL STANDARD ISO/IEC 3532-1:2023(E)
Information technology — Medical image-based modelling
for 3D printing —
Part 1:
General requirements
1 Scope
This document specifies the requirements for medical image-based modelling for 3D printing for
medical applications. It concerns accurate 3D data modelling in the medical field using medical image
data generated from computed tomography (CT) devices. It also specifies the principal considerations
for the general procedures of medical image-based modelling. It excludes soft tissue modelling from
magnetic resonance image (MRI).
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.
ISO/IEC 2382, Information technology — Vocabulary
ISO/ASTM 52900, Additive manufacturing — General principles — Fundamentals and Vocabulary
3 Terms, definitions and abbreviated terms
For the purposes of this document, the terms and definitions given in ISO/IEC 2382, ISO/ASTM 52900
and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1 Terms and definitions
3.1.1
image acquisition
scanning of the structure of interest using computed tomography (CT), magnetic resonance imaging or
other three-dimensional imaging technology
3.1.2
slice distance
slice spacing
distance between the centre of the slices, which is calculated by the difference in the slice locations of
two adjacent slices
3.1.3
hard tissue
tissue which is mineralized and has a firm intercellular matrix (such as bone, tooth enamel, dentin and
cementum)
© ISO/IEC 2023 – All rights reserved

3.1.4
soft tissue
tissue that connects, supports or surrounds other structures and organs of the body, excluding hard
tissue (3.1.3)
3.1.5
solid organ
organ which has firm tissue consistency such as the heart, kidney, liver, lungs, pancreas, etc., excluding
hollow organs (such as the organs of the gastrointestinal tract) and tissue with liquid consistency (such
as blood)
3.1.6
pixel
picture element
smallest two-dimensional element of a display image that can be independently assigned attributes
such as color and intensity
[SOURCE: ISO/IEC 2382:2015, 2125999, modified — Notes to entry have been removed.]
3.1.7
voxel
volume element
smallest three-dimensional element in volume or volumetric (solid) modelling that can be independently
assigned attributes such as colour and intensity
[SOURCE: ISO/IEC 2382:2015, 2126000, modified — Notes to entry have been removed; "solid" has
been replaced by "volume or volumetric (solid)".]
3.1.8
vector data
vector image
vector model
digital description of 2D image or 3D model stored as a series of points and mathematical functions to
describe the geometric figure
[SOURCE: ISO 12651-1:2012, 4.139, modified — "image" has been replaced by "2D image or 3D model”.]
3.1.9
raster data
raster image
raster model
bitmap data
bitmap image
bitmap model
2D image or 3D model data formed by a set of picture elements (3.1.6) or volume elements (3.1.7)
arranged in a grid pattern
3.1.10
volume model
solid model
three-dimensional geometric model which deals with the solid characteristics of an object in order to
represent its internal structure as well as its external shapes
Note 1 to entry: See ISO/IEC 2382 for definitions of volume modelling and solid modelling.
Note 2 to entry: Volume model can be represented with raster model (3.1.9) or vector model (3.1.8).
...