Filetype PDF | Posted on 21 Sep 2022 | 3 years ago
Authentication
digital resources
176x Filetype PDF File size 2.80 MB Source: www.monash.edu
Medical Teacher
ISSN: (Print) (Online) Journal homepage: https://www.tandfonline.com/loi/imte20
The reproduction of human pathology specimens
using three-dimensional (3D) printing technology
for teaching purposes
Paul G. McMenamin, Daniel Hussey, Daniel Chin, Waafiqa Alam, Michelle R.
Quayle, Sarah E. Coupland & Justin W. Adams
To cite this article: Paul G. McMenamin, Daniel Hussey, Daniel Chin, Waafiqa Alam, Michelle
R. Quayle, Sarah E. Coupland & Justin W. Adams (2021) The reproduction of human pathology
specimens using three-dimensional (3D) printing technology for teaching purposes, Medical
Teacher, 43:2, 189-197, DOI: 10.1080/0142159X.2020.1837357
To link to this article: https://doi.org/10.1080/0142159X.2020.1837357
© 2020 The Author(s). Published by Informa
UK Limited, trading as Taylor & Francis
Group.
Published online: 26 Oct 2020.
Submit your article to this journal
Article views: 1237
View related articles
View Crossmark data
Full Terms & Conditions of access and use can be found at
https://www.tandfonline.com/action/journalInformation?journalCode=imte20
MEDICAL TEACHER
2021, VOL. 43, NO. 2, 189–197
https://doi.org/10.1080/0142159X.2020.1837357
The reproduction of human pathology specimens using three-dimensional
(3D) printing technology for teaching purposes
a a a a a
Paul G. McMenamin , Daniel Hussey , Daniel Chin , Waafiqa Alam , Michelle R. Quayle ,
b a
Sarah E. Coupland and Justin W. Adams
a
Centre for Human Anatomy Education, Department of Anatomy and Developmental Biology, Biomedicine Discovery Institute, Faculty
of Medicine, Nursing and Health Sciences, Monash University, Clayton, Australia; bDepartment of Molecular and Clinical Cancer
Medicine, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, UK
ABSTRACT KEYWORDS
The teaching of medical pathology has undergone significant change in the last 30–40years, espe- Gross anatomical pathology;
cially in the context of employing bottled specimens or ‘pots’ in classroom settings. The reduction medical education; 3D
in post-mortem based teaching in medical training programs has resulted in less focus being printing; rapid prototyping;
placed on the ability of students to describe the gross anatomical pathology of specimens. additive manufacturing
Financial considerations involved in employing staff to maintain bottled specimens, space con-
straints and concerns with health and safety of staff and student laboratories have meant that
many institutions have decommissioned their pathology collections. This report details how full-
colour surface scanning coupled with CT scanning and 3D printing allows the digital archiving of
gross pathological specimens and the production of reproductions or replicas of preserved human
anatomical pathology specimens that obviates many of the above issues. With modern UV curable
resin printing technology, it is possible to achieve photographic quality accurate replicas compar-
able to the original specimens in many aspects except haptic quality. Accurate 3D reproductions
of human pathology specimens offer many advantages over traditional bottled specimens includ-
ing the capacity to generate multiple copies and their use in any educational setting giving access
to a broader range of potential learners and users.
Introduction
Anatomical pathology taught in concert with histopath- Practice points
ology, haematology, chemical pathology, microbiology, Teaching gross pathology has been in decline
immunology and related specialties is considered to pro- for decades.
vide a link between basic sciences and clinical medicine, Pathology specimens (pots) are expensive to
and its teaching is a pivotal part of the so-called ‘para- maintain and take up valuable space.
clinical years’ of undergraduate medical curricula (Marshall We have developed a method to produce exact
et al. 2004; Taylor et al. 2008; Humphreys et al. 2020). replicas using high resolution digital scanning
Historically, the teaching of human pathology in medical and UV curable resin 3D printing.
and allied health curricula relied in part upon access to 3D printing allows the production of multiple
fixed specimens in bottles or ‘pots’, which were collected copies of replicas for teaching.
over many years from post mortems and displayed in 3D printed replicas of common and rare path-
‘museums’ within university or hospital pathology depart- ology specimens can be deployed in any type of
ments (Bickley et al. 1981). The ability to recognize patho- learning environment.
logical processes and identify the underlying disease was
often part of the assessment process in many medical has become integrated into the clinical environments, such
schools. However, in the move away from a Flexnerian as tertiary hospitals. Over several decades many medical
model of medical education to modern integrated medical schools have repurposed the space occupied by their path-
curricula with case-based learning or problem-based learn- ology specimen museums (Marreez et al. 2010) and micros-
ing, pathology content has largely become integrated in a copy rooms, although some still advocate for the use of
diffuse manner into the broader curriculum (Drake et al.
2009; Buja 2019). Indeed, in many cases pathology may not such resources (Eichhorn et al. 2018). Some argue that
be identifiable as an academic discipline and many aca- pathology museums, in addition to being important resour-
demic pathology departments have been either reduced in ces for the understanding of disease pathogenesis and
size, amalgamated with related disciplines, or have disap- prognosis and the reasoning process in clinical medicine
peared altogether. In some institutions, pathology teaching (Ferrari et al. 2001), provide a reminder of progress made
CONTACT Paul G. McMenamin paul.mcmenamin@monash.edu; Justin W. Adams justin.adams@monash.edu Department of Anatomy and
Developmental Biology, Monash University, Building 13C, Wellington Rd, Clayton, Victoria, 3800, Australia
2020 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.
This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial License (http://creativecommons.org/licenses/by-nc/4.0/), which
permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
190 P. G. MCMENAMIN ET AL.
in medicine by preserving pathological collections of dis- printed normal anatomy replicas (www.3danatomyseries.
eases that either have been completely eradicated or are com) (McMenamin et al. 2014), which have been proven
very rare in modern times (Turk 1994; Barbian et al. 2012). effective in anatomy teaching (Lim et al. 2016) and a
In light of the trends described above, it could be human foetal collection (Young et al. 2019), has equipped
debated whether identification and the ability to describe us with the technical skills and resources to overcome
anatomical pathology in gross specimens is still a relevant some of the challenges of accurately recreating and repli-
and appropriate component of a modern medical under- cating colour, fine detail and 3D form, which were consid-
graduate training. Some academic pathologists still hold ered essential before embarking on producing 3D printed
the view that this domain is important in undergraduate replicas of human pathology specimens.
education (Eichhorn et al. 2018), whilst others suggest that To our knowledge, only one previous group has created
this skill is only needed during specialist pathology training 3D printed replicas of human pathology specimens
(Bell et al. 2008). The reduction in specimen-based path- (Mahmoud and Bennett 2015). These authors, who used
ology teaching in medical school programs has been in photogrammetry and ink-jet powder-based printers to cre-
part caused by a reduction in the pathology content within ate replicas of two gross specimens as proof of principle,
the curriculum as well as a greater focus on the molecular/ concluded that 3D printing of human anatomic pathology
genetic mechanisms of disease. In addition, financial con- specimens was possible and may prove valuable in educa-
siderations associated with maintaining bottled specimens, tion, medical training, clinical research, and clinicopatholog-
the shortage of storage space, and the demand for space ical correlation at multidisciplinary team meetings
for new modern teaching facilities may have contributed to (Mahmoud and Bennett 2015).
the reduced reliance on pathology specimens. At Monash University there was a large collection of
Furthermore, consent for the retention of organs has been sparingly-used pathology specimens in pots, which were
a major consideration since the publicity surrounding the collected in another era and considered of little value in
baby organ scandal associated with a pathologist working the modern age of digital technology-based teaching. This
at the Alder Hey Children’s Hospital in Liverpool UK in the pathology collection consisted of over 1800 specimens
early 1990s, where organs were kept for teaching purposes and, prior to culling and disposing of them, we undertook
without parental consent (Dewar and Boddington 2004). a triage process, reviewing the material and choosing
This scandal led to the tightening of the Human Tissue Act examples of both common pathologies and rare cases that
and all research associated with human tissues in the UK. we considered would be useful for teaching if they could
Old bottled specimens often pre-date this case and their be replicated at a suitable level of detail that mimicked the
provenance, as well as whether consent for their retention real specimen. This paper describes the process in select-
was properly sought, can be ambiguous. Furthermore, in ing, scanning, describing and 3D printing some of the
some countries cultural and ethical considerations, and the Monash University pathology collection. The value of 3D
rural location of some institutions, mean that many medical printing some of the collection is that it allows us to dis-
schools or colleges involved in educating doctors and other pose of the original pots, reducing costs of handling and
allied disciplines have difficulties accessing human path- storage, and furthermore allows students to physically han-
ology specimens. dle pathology replicas in facilities other than licenced anat-
Additive manufacturing, more commonly described as omy laboratories.
3D printing, is a rapidly expanding technology that is now
a critical part of the iterative design process in engineering, Material and methods
producing physical models or prototypes quickly, easily Selection of pathological material for 3D printing
and inexpensively from computer-aided design (CAD) and
other digital data (Pham and Dimov 2001). In the medical Approximately 1800 bottled or potted specimens used in
and healthcare arena, 3D printing technology showed this study were held in The Centre for Human Anatomy
great promise as early as 1997 (McGurk et al. 1997). It has Education, Department of Anatomy and Developmental
already had an impact in the domain of pre-surgical plan- Biology at Monash University. Around 1100 of these were
ning (Isolan et al. 2007; Cohen et al. 2009; Tam et al. 2013; originally displayed in the Department of Pathology and
Chae et al. 2015; Abla and Lawton 2015; Stramiello et al. Immunology, Faculty of Medicine, Nursing and Health
2020) and orthopaedic surgery as well as in other disci- Sciences, Monash University, at the Alfred Hospital in
plines by allowing the production of bespoke prefabricated Melbourne Australia. For many of the other specimens
bone models for pre-surgical planning or the creation of there was no known provenance. Many specimens were
patient-specific prostheses, or as patient educational tools collected at operation or during post-mortem examination
(see review, Rengier et al. 2010; Aimar et al. 2019; Morgan in the 1950s–1960s. Specimens represented the major
et al. 2020). body systems including cardiovascular, lymphatic, endo-
Whilst it is theoretically possible to use data from crine, respiratory, alimentary, liver and biliary, kidney and
patient-derived CT/MRI data medical imaging to generate urinary, male and female reproductive, breast, skin, muscu-
3D prints, the resolution of most clinical radiographic data loskeletal and central and peripheral nervous systems. The
is often below that needed to capture vital 3D morphology Department of Pathology and Immunology at Monash
and, of course, lacks colour. Despite those limitations we University pots had been displayed with a description
and others have shown it is possible to generate useful including brief patient history and a conventional photo-
bespoke 3D prints from such radiographic data (Lioufas graph. In 1995Dr Ruth Salom converted the images and
et al. 2016; Bennett et al. 2018; Nagassa et al. 2019). Our descriptions to create an online learning resource (https://
experience in producing a successful collection of 3D www.monash.edu/museumofpathology). The collection was
MEDICAL TEACHER 191
donated to The Department of Anatomy and outdated medical terms which are no longer applicable.
Developmental Biology, Monash University in the late For each specimen, an updated clinical history and path-
1990s. A limited number (approx. 200) of specimens were ology description was thus created and outdated terms
displayed in the Human Anatomical Sciences Learning were modernized. For the few specimens with no previous
Resource Centre for use in medical education until 2010, clinical description, an entirely new and plausible clinical
whilst the remaining 1600 pots were stored in archives. history was generated.
Most of the specimen descriptions did not contain any
Criteria for culling the archived collection and further information about the disease processes involved.
selecting valuable specimens To increase the utility of the 3D printed pathology collec-
tion from introductory undergraduate pathology through
To ensure that most body systems were represented two more advanced teaching, we developed a brief overview of
senior non-medically qualified anatomists (PMcM, JWA) the disease process was generated for each 3D print. The
examined the collection of pathology pots. Poor quality overviews included where possible an introduction of the
pots with damaged or degenerated specimens or with dis- disease, epidemiology, risk factors/genetics, symptoms/
colored fluids reflecting potential deterioration of the tis- signs, diagnosis and treatment. The main sources of infor-
sues were initially culled. The next level of selection was mation used in the creation of these overviews was
based on representing each of the major body systems Robbins and Cotran’s Pathological Basis of Disease (Kumar
and, if multiple copies were noted, the best specimens et al. 2014), PubMed and UpToDate.com.
were retained and the others destroyed. If the pathology
described in the notes (where available) was not evident Image data acquisition and manipulation
on examination the specimen was rejected. Rare patholo-
gies as well as common pathologies were then chosen for The precise threshold of resolution required for 3D printed
retention. Every attempt was made to not over-represent replicas to be useful for haptic teaching aids is not pres-
any one particular body system in the final number, a tar- ently known, but the majority of 3D printers are capable
get sample of approximately 100, a number of specimens of producing 100 mm Z-axis additive layers, and latest
which was considered feasible for our laboratory to scan generation 3D scanning equipment (such as fixed or hand-
and 3D print. One further selection criterion included held surface scanners) are capable of comparable (or
whether the pathology could be represented just as clearly higher) resolution during 3D mesh generation. A modern
in a 2D photograph (and therefore not necessitating 3D 64 slice CT scanner typically involves lower resolutions; for
scanning or printing for teaching purposes). If this was the example, a CT scan of a limb segment would produce
case, the specimen was generally rejected. voxel sizes with X and Y spatial resolutions 0.15–0.5mm
Once the specimens were scanned (see below), we and Z spatial resolution of 0.41.0mm (O’Connor and
engaged three medically qualified junior doctors (DH, DC, Kemp 2006). Thus, as long as printer resolution is higher
WA) who had completed undergraduate pathology and than the scan resolution, 3D printing will not result in any
anatomy education and who were employed as anatomy loss of resolution. We initially considered using CT scanning
demonstrators in the Centre for Human Anatomy to capture surface topography followed by false digital col-
Education, Department of Anatomy and Developmental ouring as was undertaken for the normal anatomy series
Biology at Monash University during the course of 2019. (McMenamin et al. 2014). Trials of this approach (Figure 1)
These junior medical doctors were destined for training in and use of existing powder-based 3D printers showed that
their chosen careers in surgery, pathology and radiology. it was difficult to obtain realistic colour rendition. There
This small group firstly impartially assessed the quality and was thus a dilemma in the method chosen to colouring of
accuracy of approximately half of the 3D prints. They com- 3D printed models: was it best to make it resemble the
pared the final 3D prints to the original potted specimens; dull greys and light browns of the potted specimen, or
both original specimens in their containers and old photo- would the more saturated tones of a fresh unfixed speci-
graphs. All descriptions, clinical cases and further informa- men (i.e. replicating the post-mortem appearance) make it
tion pertaining to the specimens were checked by the more realistic? In the end, we considered it more vital that
senior author (PMcM) and further cross fact-checked by a surface detail and subtle colour fidelity and detail of the
qualified senior pathologist (SEC). Comparison of the 3D potted specimen was captured as these are more critical to
prints to the original specimen was made using the criteria illustrating pathological processes and more consistent
of accuracy of pathological structure, colour representation, with what students would normally be exposed to in the
and capture of the fine surface topography. Feedback was modern era, due to the paucity of opportunities for under-
provided to our Technical Officer who managed the 3D graduates to attend post-mortems.
printing laboratory (MRQ), and who was able to readjust To obtain high quality 3D printed models of cadaver
the 3D prints in order to optimize their fidelity close to the specimens it was vital that the original pathology specimen
original specimen to enhance their educational value. was in the best possible condition as per the selection cri-
In order to enhance their utility in both a formal educa- teria described above. Each pathology specimen was
TM TM
tional setting as well as independent study by students, we scanned using an Artec Spider /Space Spider hand-held
developed 3D prints that would be accompanied wherever 3D scanner (Artec Group, Luxembourg) with a manufac-
possible by an updated synopsis of the clinical history of turer stated 3D point accuracy up to 0.05mm and 3D
the patient, a macroscopic description of the specimen and mesh resolution up to 0.1mm. The Artec Spider captures
an overview of the disease process affecting the specimen. geometry as well as texture (e.g. colour) information from
Many of the existing clinical histories provided used the specimen which is then modelled in the associated
no reviews yet
Please Login to review.
