Education

EAU Standardised Medical Terminology for Urologic Imaging:

A Taxonomic Approach

Tillmann Loch a,*, Brendan Carey b, Jochen Walz c, Pat Fox Fulgham d,

for the European Association of Urology Guidelines Office Ad Hoc Working Group onUrological Imaging

a Klinik fur Urologie, Diakonissenkrankenhaus Flensburg, Lehrkrankenhaus der Christian-Albrechts-Universitat, Flensburg, Germany; b St. James Institute of

Oncology, Leeds, UK; c Department of Urology, Institute Paoli-Calmettes Cancer Centre, Marseille, France; d Department of Urology, Texas Health Presbyterian

Hospital Dallas, Dallas TX, USA

E U R O P E A N U R O L O G Y 6 7 ( 2 0 1 5 ) 9 6 5 – 9 7 1

ava i lable at www.sciencedirect .com

journal homepage: www.europeanurology.com

Article info

Article history:

Accepted August 5, 2014

Keywords:

Computed tomography

EAU guidelines

Magnetic resonance imaging

Positron emission tomography

Radiographs

Taxonomy

Terminology

Ultrasound

Urologic imaging

Abstract

Background: The terminology and abbreviations used in urologic imaging have generallybeen adopted on an ad hoc basis by different speciality groups; however, there is a need forshared nomenclature to facilitate clinical communication and collaborative research.Objective: This work reviews the current nomenclature for urologic imaging used inclinical practice and proposes a taxonomy and terminology for urologic imaging studies.Design, setting, and participants: A list of terms used in urologic imaging were compiledfrom guidelines published by the European Association of Urology and the AmericanUrological Association and from the American College of Radiology AppropriatenessCriteria.Outcome measurements and statistical analysis: Terms searched were grouped intobroad categories based on technology, and imaging terms were further stratified basedon the anatomic extent, contrast or phases, technique or modifiers, and combinations orfusions. Terms that had a high degree of utilisation were classified as accepted.Results and limitations: We propose a new taxonomy to define a more useful andacceptable nomenclature model acceptable to all health professionals involved inurology. The major advantage of a taxonomic approach to the classification of urologicimaging studies is that it provides a flexible framework for classifying the modificationsof current imaging modalities and allows the incorporation of new imaging modalities.The adoption of this hierarchical classification model ranging from the most general tothe most detailed descriptions should facilitate hierarchical searches of the medicalliterature using both general and specific terms. This work is limited in its scope, as it isnot currently all-inclusive. This will hopefully be addressed by future modification asothers embrace the concept and work towards uniformity in nomenclature.Conclusions: This paper provides a noncomprehensive list of the most widely usedterms across different specialties. This list can be used as the basis for further discussion,development, and enhancement.Patient summary: In this paper we describe a classification system for urologic imagingterms with the aim of aiding health professionals and ensuring that the terms used aremore consistent.

# 2014 European Association of Urology. Published by Elsevier B.V. All rights reserved.

* Corresponding author. Klinik fur Urologie, Diakonissenkrankenhaus Flensburg, Knuthstrasse 1,24939 Flensburg, Germany. Tel. +49 461 812 1401; Fax: +49 461 812 1402.E-mail address: lochti@diako.de (T. Loch).

http://dx.doi.org/10.1016/j.eururo.2014.08.0140302-2838/# 2014 European Association of Urology. Published by Elsevier B.V. All rights reserved.

1. Introduction

The continued development of new imaging techniques in

urology has had considerable impact on both clinical

practice and urologic research [1,2]. The clinical integration

of these imaging techniques into urologic practice involves

contributions from investigators and clinicians of varied

backgrounds including physics and engineering, informat-

ics, urology, and radiology. Each profession has its own

jargon, a specialised language that allows for rapid and

efficient communication between members of the same

profession while minimising the potential for misunder-

standings. Abbreviations are an extension of the jargon of

each profession, and they enable health care professionals

to document their work more easily and communicate

quickly.

Abbreviations have generally been adopted on an ad

hoc basis to accommodate the often conflicting demands

of utilising brief context-sensitive phrases and combina-

tions of letters with the challenging requirements of more

rigid, computer software–driven, clinical and research

practice; however, this jargon might lead to the problem

of several terms for the same object. The differences in

terminology and the lack of standardisation of the

terminology can lead to confounders, errors, and mis-

understandings as well as to loss of information and

knowledge.

Most of this development and expansion of terminology

has occurred in an unplanned and uncoordinated manner

and has been adopted through common usage within

specialities rather than by consensus agreement [3].

Various lists of abbreviations and terminologies have been

produced by different speciality groups [4,5]. During the

review, it was found that a wide variety of terms were used

for the same examination, for example, intravenous urogram

(IVU) was also termed kidney, ureter, bladder (KUB) urogram

or urography.

Much of this usage has been driven by agreed common

practice without reference to any unifying standard of

methodology or taxonomy. Taxonomy is a general principle

of scientific classification. Organisms are classified into a

hierarchy of groupings. The order of ranking is usually from

the more general to the more specific to describe and reflect

a morphologic relationship [6].

There has been a general lack of international

cooperation among different specialities and among

different geographic locations for the same speciality.

Confusion between the different requirements for digital

archive coding systems and research may cause a lack of

support to integrate data produced by everyone involved

in urology imaging and further promote a diversity of

interests.

The benefits of a shared nomenclature for literature

research and communication among clinicians are obvi-

ous. The absence of agreed-on operational nomenclature

will inevitably undermine the yield from literature

review if different search terms are used. The aim of

this work is to review the current nomenclature used for

imaging in urology in clinical practice and in the

published literature and to propose standardisation of

terms using taxonomy.

2. Methods

The list of terms used for urologic imaging was compiled from guidelines

published by the European Association of Urology (EAU) [7], the

American Urological Association (AUA) [8], and the American College of

Radiology (ACR) [9]. These guidelines are regularly updated and based on

extensive review of the current literature.

A review of the different guideline texts, which included the

terminology and abbreviations found in the reference listings for each

guideline, showed that the same examination might have a variety of

names. As noted, IVU was also called KUB urogram or urography.

To investigate the terms used, the AUA and EAU guidelines and all of

the urology-related ACR Appropriateness Criteria were downloaded into

single directories. Using the advanced search feature of Acrobat Pro (CTRL-

SHIFT-F; Adobe Systems Inc., San Jose, CA, USA), we searched for the terms,

for example, CT or computed tomography (identical methodology for all

other terms) and identified all of the various terms, abbreviations, and

variants associated with them. Once the terms were identified, each term

was then grouped by its operating characteristics. Specifically, terms were

divided by the type of study (eg, computed tomography [CT]), anatomic

extent (eg, area researched such as abdomen or pelvis), the use of contrast

and phases, the technique or type of detector (eg, multiphase, helical, low

dose), and combined studies or fusions (eg, positron emission tomography

[PET], CT). Based on the frequency of use and expert consensus, the terms

were then placed in an accepted category or an equivalent or similar

category. The categories were ranked by frequency of use within the

documents. Imaging terms were grouped into broad categories based on

technology (eg, plain radiography, CT, ultrasound, magnetic resonance

imaging [MRI], and nuclear medicine). Within each broad category, the

imaging terms were further stratified based on the anatomic extent,

contrast or phases, technique or modifiers, and combinations or fusions.

Terms that had a high degree of utilisation were classified as accepted.

Other terms were judged to be similar but were either infrequently used or

contained modifiers requiring further explanation.

To construct a general methodology for nomenclature adaptation in

medical terminology, we propose that a taxonomy-based approach

would help define a more useful model that would be acceptable to all

health professionals involved in urology.

2.1. Rationale for a taxonomic approach

The major advantage of a taxonomic approach to the classification of

urologic imaging studies is that it provides a flexible framework for

classifying the modifications of current imaging modalities and allows

for the incorporation of new imaging modalities. Adopting this

hierarchical classification model (ie, from the most general to the most

detailed descriptions) should facilitate hierarchical searches of the

medical literature using both general and very specific search terms.

3. Results

Tables 1–7 summarise the findings of the systematic search

for all major types of urologic imaging studies: ultrasound

(US); CT; MRI; fluoroscopy; radiographs; PET, in combina-

tion with either CT (PET-CT) or MRI (PET MRI); and

scintigraphy. In the tables, the most commonly used term

is listed as the accepted standard, and less frequently used

terms are listed under glossary of other terms, which should

be replaced by the accepted standard.

E U R O P E A N U R O L O G Y 6 7 ( 2 0 1 5 ) 9 6 5 – 9 7 1966

Table 1 – Taxonomic classification of ultrasound

Root name Anatomicextent

Contrast/phases

Technique modifiers/postprocessing methods

Combinations/fusions

Accepted standard Ultrasound

US

Abdomen

Kidney

Ureter

Bladder

Penis

Testis

Scrotum

Prostate

Pelvis

Vas

Vessels

Noncontrast

Contrast

TRUS

Transvaginal

Transurethral

Transvesical

Intra-abdominal

Transabdominal

Elastography

C-TRUS/ANNA

Histoscanning

Doppler

Colour Doppler

Power Doppler

Spectral Doppler

Compound imaging

Harmonic

MRI

CT

Glossary of terms less widely acceptable

(descending order based on use in

current guidelines)

Ultrasonography

Sonography

Endosonography

Percutaneous

ANNA = artificial neural network analysis; CT = computed tomography; C-TRUS = computerised transrectal ultrasound; MRI = magnetic resonance imaging;

TRUS = transrectal ultrasound; US = ultrasound.

Example: ‘‘US, prostate, TRUS, C-TRUS/ANNA fused with MRI’’.

Table 2 – Taxonomic classification for computed tomography

Root name Anatomicextent

Contrast/phases Techniquemodifiers

Combinations/fusions

Accepted standard Computed tomography

CT

Chest

Abdomen

Pelvis

Abdomen and

pelvis

Contrast

Noncontrast

urography

Multiphasic

Multidetector

PET/CT

Glossary of terms less widely

acceptable

(descending order based on use

in current guidelines)

Computer tomography

Computer-aided

tomography scan

CAT scan

CT scan

Scan

Contrast-enhanced CT

Noncontrast CT

Nonenhanced CT

Unenhanced CT

Unenhanced spiral CT

CT cystography

CT angiography

CT scout

Intravenous CT angiography

Three-phase helical CT

Multidetector row CT

Single detector CT

Multiphase CT

Multiphasic CT

Multiphasic CT urography

Multiphasic CTU

Low-dose CT

Standard-dose CT

Ultra-low-dose CT

CAT = computer-aided tomography; CT = computed tomography; CTU = computed tomography urography; PET = positron emission tomography.

Example: ‘‘CT, renal arteries, contrast, multiphasic’’.

Table 3 – Taxonomic classification for magnetic resonance imaging

Root name Anatomicextent

Contrast/phases Techniquemodifiers

Combinations/fusions

Accepted standard Magnetic resonance

imaging

MRI

Whole body

Abdomen

Pelvis

Genitals

Prostate

Kidney

Testis

Penis

Urinary tract

T1 weighted (T1)

T2 weighted (T2)

Dynamic contrast enhanced

Diffusion weighted imaging

Spectroscopy

Multiparametric

1.5 tesla (1.5T)

3 tesla (3T)

7 tesla (7T)

Body array coil

Rectal coil

Surface coil

PET/MRI

Glossary of terms less

widely acceptable

(descending order based

on use in current

guidelines)

Magnetic resonance

MR

Nuclear magnetic

resonance

NMR

MRI urography

Contrast-enhanced MRI

Nonenhanced MRI

Unenhanced MRI

MRI cystography

MRI angiography

Functional MRI

Molecular MRI

Molecular imaging

Open-gantry MRI

Regular-gantry MRI

Interventional MRI

Thermometrie

DCE = dynamic contrast enhanced; DWI = diffusion weighted imaging; MP = multiparametric; MR = magnetic resonance; MRI = magnetic resonance imaging;

NMR = nuclear magnetic resonance; PET = positron emission tomography.

Example: ‘‘MRI, prostate, T2, DCE, DWI, MP, 1.5T, surface coil’’.

E U R O P E A N U R O L O G Y 6 7 ( 2 0 1 5 ) 9 6 5 – 9 7 1 967

Table 4 – Taxonomic classification of fluoroscopy

Root name Anatomicextent

Contrast/phases

Techniquemodifiers

Combinations/fusions

Accepted standard Fluoroscopy Chest

Abdomen

Pelvis

Renal tracts

Noncontrast

Contrast

CT fluoroscopy

Intraoperative

Glossary of terms less widely acceptable

(descending order based on use in current guidelines)

Fluorography

CT = computed tomography.

Example: ‘‘Fluoroscopy, renal tract, contrast, intraoperative’’.

Table 5 – Taxonomic classification of radiographs

Root name Anatomicextent

Contrast/phases

Techniquemodifiers

Combinations/fusions

Accepted standard Radiographs

Plain x-rays

Intravenous urogram

Chest

Abdomen

Pelvis

Spine

Extremities

Renal tract

Conventional

Digital

Antegrade

Retrograde

CT-urogram

Glossary of terms less widely acceptable

(descending order based on use in

current guidelines)

Plain films

Radiography

KUB

Intravenous

Pyelogram

Excretion Urography

Nephrostogram

Kidneys, ureters,

bladder

Urethra

Vas

Plain Radiography

CT

Ascending

Descending

CT-KUB

CT-nephrostogram

CT-urethrogram

CT = computed tomography; IVU = intravenous urogram; KUB = kidney, ureter, and bladder.

Example: ‘‘IVU, renal tract, digital’’.

Table 6 – Taxonomic classification of positron emission tomography in combination with either computed tomography or magneticresonance imaging

Root name Anatomic extent Technique modifiers(isotope)

Accepted standard Positron emission tomography–

computed tomography

PET-CT

Whole body

Pelvis

Kidney

Bladder

Prostate

Abdomen Retroperitoneum

Fluorodeoxyglucose11C-choline18Fluorine

Methionine

Other (nonspecified)

Glossary of terms less widely acceptable

(descending order based on use in

current guidelines)

CT-PET

FDG-PET18FDG-PET

PET

FDG-PET CT

Accepted standard Positron emission tomography

magnetic resonance imaging

PET MRI

Whole body

Pelvis

Kidney

Bladder

Prostate

FDG

Choline

Acetate

Glossary of terms not to be used

(descending order based on use in

current guidelines)

PET/MRI

PET-MRI

fluoro deoxy glucose18F-choline11C-acetate18F-acetate

Other

18FDG-PET = 18fluorine-fluorodeoxyglucose positron emission tomography; CT = computed tomography; FDG = fluorodeoxyglucose; MRI = magnetic resonance

imaging; PET = positron emission tomography.

Example: ‘‘PET CT, Abdomen, 11C- choline’’.

E U R O P E A N U R O L O G Y 6 7 ( 2 0 1 5 ) 9 6 5 – 9 7 1968

4. Discussion

4.1. Rationale for advocating the use of a unified nomenclature

In our review of the terminology used for imaging studies in

clinical urologic practice, research, and publication, we

found that terms used for the same studies were not

uniform (Supplementary Tables 1–3). We found that there

is no standardised or recommended terminology for these

imaging studies. There are more general, ongoing efforts to

standardise the different vocabularies used in health care.

The Unified Medical Language System (UMLS) [10]

developed by the US National Library of Medicine is a set

of files and software that link the major international

terminologies into a common structure, allowing for

efficient translation and interoperability. The UMLS cur-

rently includes vocabularies from about 140 different

sources that can be used for the exchange of information.

The Systematized Nomenclature of Medicine Clinical

Terms (SNOMED CT) [11] is a reference terminology

standard available through the UMLS consisting of concepts

and terms and the interrelationships between them. The

Health Terminology Standards Development Organisation

is responsible for promoting the international adoption of

SNOMED CT. It standardises the way health care terminol-

ogy and data are recorded and aims to facilitate the coding,

retrieval, analysis, aggregation, indexing, and exchange of

clinical information across different health care entities.

SNOMED CT was designed for use in software applications

to represent clinically relevant information in a reliable and

reproducible manner.

In a similar way, different professional groups have

adopted varying terminology for similar imaging investiga-

tions. Our ability to communicate effectively across medical

and scientific disciplines may be hindered by inconsistent

use or inadvertent misinterpretation of commonly used

abbreviations and acronyms. These terminology variations

are evident across different health care systems in different

countries and across individual disciplines of clinical and

scientific interest.

There are a variety of abbreviations and synonyms for

similar investigations, with overlapping definitions that can

potentially confuse or misdirect clinicians and researchers

(Supplementary Tables 1–3). The language of medicine is

complex, and there is a justifiable need to avoid undue

repetition and offer clarity to researchers and clinical

specialists. Many abbreviations and acronyms that are

readily understood within different professional disciplines

may not be easily extrapolated to other areas of medical,

and specifically urologic, practice.

The advent of the digital era in imaging has added a

further layer of complexity to the terminology used for

imaging procedures. The requirements of various digital

systems to code and file huge volumes of imaging data has

prompted the development of additional abbreviations and

synonyms to organise and search for data within and

between digital networks. Within these coding systems,

individual studies are represented by specific identifiers,

which are usually a combination of characters (letters and/

or numbers) that have no meaning in themselves. This

coded representation is then used in place of the natural

language description of the concept for further computer or

human processing. Standardised clinical vocabularies also

generally include a coding system. An example of a coded

system is Medline’s Medical Subject Headings [12].

Different professional groups (eg, radiologists, urolo-

gists, health care providers) have ad hoc lists that have been

adopted and incrementally amended in recent years. Large

international databases such as the Cochrane Library [13]

and Medline [14] have guidelines for the use of abbrevia-

tions and acronyms without being prescriptive or exclusive.

The Cochrane Library, for example, advises using abbrevia-

tions and acronyms only if they are widely known and

states that not using them ‘‘would make literature reading

tedious’’ [13].

4.2. Guidelines

Panels charged with writing clinical guidelines must

evaluate the existing literature regarding medical practice

and make judgments, first, about the quality of the data and,

next, about the clinical effectiveness of the procedure, the

risks and harms associated with the procedure, and the

costs of the procedure.

Table 7 – Taxonomic classification of scintigraphy

Root name Anatomic extent Contrast/phases Combinations/fusions

Accepted standard Scintigraphy Bone

Kidney

Testis

Bladder

99m Technetium

DMSA

MAG3

DTPA

SPECT

Glossary of terms less widely acceptable

(descending order based on use in

current guidelines)

Radionuclide scintigraphy

Nuclear scintigraphy

Radiographic scintigraphy

Isotope scintigraphy

Radioisotope scintigraphy

Bone scan

Bone scintigraphy

Renal scintigraphy

Renal cortical scintigraphy

Isotope renogram

Isotope renography

Scrotum scintigraphy

Scintigraphy of the testis

Radioisotope cystography

Dimercaptosuccinic acid

Mercaptuacetyltriglycine 3

Captopril scintigraphy

99mTc = 99m technetium; DMSA = dimercaptosuccinic acid; MAG3 = mercaptuacetyltriglycine 3; SPECT = single-photon emission computed tomography.

Example: ‘‘Scintigraphy, Bone, 99mTc’’.

E U R O P E A N U R O L O G Y 6 7 ( 2 0 1 5 ) 9 6 5 – 9 7 1 969

Medical imaging is a complex technological procedure

with many variables that affect efficacy, risk, and cost. It is

difficult to evaluate the quality of the data when multiple

terms describe the same imaging procedure and imaging

procedures that share a common name but have vastly

different operating characteristics (eg, radiation dose,

number of exposures).

Evaluations of existing guidelines from the EAU, the AUA,

and the ACR have demonstrated wide variability in terms

associated with imaging. We have attempted to define the

range of terms within the existing guidelines and then

proposed a strategy for naming these imaging studies. The

proposed strategy should improve the ability to compare

outcome data using similar methodologies and ultimately

will encourage the use of consistent terminology when

constructing new guidelines [15].

In an effort to unify the terminology used in the imaging

of urologic conditions, this EAU imaging panel compiled a

list of terms commonly used in clinical and investigative

urology. The panel focused on terms most relevant to

urology. Not included within the scope of this document are

more general terms related to the details of imaging. These

were considered to be already well understood and

documented in the literature of their respective fields.

Finally, terms that were considered interchangeable with-

out being ambiguous or requiring further clarification were

not considered for this document.

5. Conclusions

The current list will form the basis for further discussion,

development, and enhancement. The expert panel would

like to stress that it has incorporated the most widely used

terms across different specialities, avoiding any subjective

selection of a term and aiming for objective selection of the

most commonly used term for an imaging technique.

Despite this, the proposed list (especially the glossary) is

probably not complete. Consequently, the resulting list is

not all-inclusive or comprehensive.

The proposed terminology is intended to promote unified

nomenclature in both clinical and research settings. It is not

intended to be used for administrative and billing purposes.

Different health care administrative systems already have

different agreed terminologies based on individual require-

ments, and our tables are not intended to replace these.

It is anticipated that by adopting such a standardised

terminology, all professional disciplines involved in the

field of urologic imaging will benefit from better commu-

nication across specialities.

In particular, for those involved in research, unified

terminology should enhance the yield of evidence from

literature searches and thus help promote the dissemina-

tion of findings as different professional groups publish

within their own literature bases using commonly agreed

terminology.

Author contributions: Tillmann Loch had full access to all the data in the

study and takes responsibility for the integrity of the data and the

accuracy of the data analysis.

Study concept and design: Loch, Carey, Walz, Fulgham.

Acquisition of data: Loch, Carey, Walz, Fulgham.

Analysis and interpretation of data: Loch, Carey, Walz, Fulgham.

Drafting of the manuscript: Loch, Carey, Walz, Fulgham.

Critical revision of the manuscript for important intellectual content: Loch,

Carey, Walz, Fulgham.

Statistical analysis: Loch, Carey, Walz, Fulgham.

Obtaining funding: Loch, Carey, Walz, Fulgham.

Administrative, technical, or material support: Loch, Carey, Walz, Fulgham.

Supervision: Loch, Carey, Walz, Fulgham.

Other (specify): None.

Financial disclosures: Tillmann Loch certifies that all conflicts of

interest, including specific financial interests and relationships and

affiliations relevant to the subject matter or materials discussed in the

manuscript (eg, employment/affiliation, grants or funding, consultan-

cies, honoraria, stock ownership or options, expert testimony, royalties,

or patents filed, received, or pending), are the following: Loch holds

equity interests in ANNA/C-TRUS GmbH, and receives company speaker

honoraria from Takeda and GSK. Walz receives company speaker

honoraria from: Supersonic, Hitachi, Takeda. The other authors have

nothing to disclose.

Funding/Support and role of the sponsor: This guidelines document was

developed with the financial support of the EAU, which is a non-profit

organisation. No external sources of funding and support were used. EAU

funding was limited to administrative assistance and travel and meeting

expenses. No honoraria or other reimbursements were provided. The

Imaging Expert Panel has submitted potential conflict of interest

statements, which can be viewed on the EAU website: http://

www.uroweb.org/guidelines/.

Acknowledgment statement: This document was externally peer

reviewed by representatives from several organisations (National

Institute of Clinical Excellence, the European Society of Urologic Imaging,

ad hoc panel members of the American Urological Association and the

American College of Radiology) as well as the current chairmen of the

European Association of Urology (EAU) guideline panels. This publica-

tion is the first approach addressing the issue of imaging terminology by

the EAU Guidelines Office. The authors would like to thank the Guideline

Office Board, the Panel Chairman, and the Central Office of the EAU for

their constructive support during the process.

Appendix A. Practical points

Details should be carefully noted, for example, consis-

tency of punctuation is essential so that the term is IVU and

not I.V.U. Nonspecific terms such as plain films should not be

used.

It may generally be helpful to write the name of the

abbreviation or acronym in full, immediately followed by the

abbreviated version or acronym in brackets: computed

tomography (CT). A list of the most commonly used terms

and abbreviations can be found online (http://www.uroweb.

org/guidelines/eau-standardised-medical-terminology-for-

urologic-imaging/).

Appendix B. Supplementary data

Supplementary data associated with this article can be

found, in the online version, at http://dx.doi.org/10.1016/

j.eururo.2014.08.014.

E U R O P E A N U R O L O G Y 6 7 ( 2 0 1 5 ) 9 6 5 – 9 7 1970

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