Translating Diagnostic Imaging

The following explains just two of many DI modalities: radiography and computed axial tomography.

Diagnostic imaging (DI) is the process of generating a visual representation of the inside of the body for medical diagnosis and treatment. Many DI modalities exist—e.g., radiography, computed axial tomography (CAT or CT) scan, magnetic resonance imaging (MRI), ultrasound, and scintigraphy—and each has particular applications to which it is best suited. DI examinations of patients are generally interpreted by physicians called radiologists, who adhere to a specific structural formula and specialized vocabulary to report their findings. These reports are often extremely concise and dense, limiting the contextual clues translators often rely upon. Translating these reports can be a challenging but rewarding aspect of medical translation for which the translator must master the technical basics of the diagnostic imaging modality, the report structure, and the specialized source and target vocabulary.

The following explains just two of many DI modalities: radiography and computed axial tomography. It provides some terminology commonly found in DI reports and shares French>English translation examples from actual DI reports to illustrate some of the challenges and solutions to translating these accurately. Although the examples are language-specific, the information presented is useful to others considering work in this area.


Radiography involves directing certain wavelengths of radiation through a particular part of the body. Depending on their density, body tissues absorb or attenuate the radiation to varying degrees. The information produced in this process is then collected to form an image of the body part, called a radiograph or, more colloquially, an X-ray. Radiography is one of the least expensive and most widely available diagnostic imaging modalities. It is often available onsite in doctors’ offices.

Radiography is best used to detect bone lesions, such as simple fractures (those consisting of only two bone fragments), masses, or infections, as well as lesions of the thorax, such as pneumonia, or air or fluid in the thoracic cavity. Radiology is also used for screening purposes, such as mammograms for breast cancer. Radiography, however, is not a particularly sensitive DI modality, so it is not as well-suited for detecting very subtle lesions (such as very small lung metastases) or imaging complex fractures (those consisting of more than two bone fragments). It also does not provide good contrast between tissues that differ only slightly in density, such as the gray and white matter of the brain (MRI and CT are superior DI approaches for this).

Areas of interest on radiographs are described in terms of radio-opacity and radiolucency, depending on how white or black they look. Radio-opaque designates areas that appear white, and radiolucent areas that are black. In a normal thoracic radiograph, the lungs appear radiolucent and the bone is radio-opaque. Any metal on the radiograph (e.g., a directional marker or an implant) appears bright white, as metal is even more radio-opaque than bone. The soft tissues (e.g., the heart and diaphragm) appear as shades of gray, falling along a spectrum between these two poles. Thus, soft tissue may be described as more radiolucent than bone, but more radio-opaque than the lungs.

Translation Challenges

Translating French DI imaging involves many challenges, but a primary one is the lack of one-to-one correspondence between French and English terms and acronyms. For example, thoracic radiographs are often generically called “chest X-rays” in English, but in French the same imaging examination can have several names: radio du poumon (chest X-ray), radiographie poumon (lung radiograph), radiographie thorax (thoracic radiograph), radio thorax (thoracic radiograph), and radiographie pulmonaire (pulmonary radiograph). Of course, these same terms also correspond to the common French acronyms “RxT” (radiographie thorax) and “RP” (radiographie poumon), creating a veritable “alphabet soup” of terminology.

However, the translation challenges go beyond just the terminological level. The following sentence is from the impression section of an actual French DI report:

On revoit la présence d’un épanchement pleural droit qui remonte le long de la ligne axillaire sans franc changement par rapport à l’étude précédente.

In this example, the third-person singular personal pronoun “on” is the subject of the French sentence. This is a common quandary in French>English medical translation. While “on” is equivalent to the pronoun “one” or “we” in English, the target syntax and register should reflect standard English medical writing. Since standard English medical writing avoids personal pronouns (I, we, etc.) as much as possible, the passive voice should be used to avoid the difficulties of translating “on” into English. Thus, an appropriate translation of the above example would be:

“Right pleural effusion again observed that reaches the length of the axillary line without clear changes from the previous study.”

Another important takeaway is to be aware of the terminology used in the positioning and landmarking of anatomical features on an examination. For example, in the previous examples, the “axillary line,” or ligne axillaire, refers to a geographic location on the patient’s body, where axilla means “armpit.” Describing the anatomical landscape is essential when reporting observations and/or changes on imaging exams, so translators must be able to translate these descriptions correctly. While this may be daunting at first, these anatomical descriptors are finite in quantity and frequently repeated. Therefore, while the learning curve may be steep initially, a good glossary and termbase are worthy investments. (We have included some resources to assist translators unfamiliar with radiological anatomy in the sidebar on page 26.)

Computed Axial Tomography (CAT)

A second significant diagnostic imaging modality is computed axial tomography (CAT or CT). A CAT scan is essentially an expanded radiograph that involves collecting a large number of radiographic cross-sections using a fan-shaped beam of radiation. These are then integrated into one three-dimensional image. A useful analogy is to think of the individual cross-sections as slices of bread and the full CAT scan as a “loaf” comprising these slices. With computers, the CAT scan data can be processed and modified to provide different perspectives of the body part(s) being examined and to highlight various features that yield the most information to radiologists and clinicians.

CAT is based on radiography, but it involves a much higher dose of radiation to the patient than a plain X-ray and is a much more specialized and expensive test. Thus, it is unlikely to be a primary care doctor’s first-line diagnostic tool, but it is tremendously informative in the appropriate cases. CAT scans are best used for imaging brain lesions, such as tumors or hemorrhages, complicated or subtle fractures (e.g., of the hip), and small metastases (e.g., lung metastases of bone cancer).

Areas of interest on CAT scans are described along a spectrum similar to that in radiography. However, the terms utilized in CAT scans are hyperdense and hypodense. Areas that appear whiter are called hyperdense and those appearing blacker are called hypodense. For instance, on a cerebral CAT scan, blood appears whiter, or hyperdense, relative to the surrounding brain tissue. Images containing these hyperdense areas might suggest cerebral hemorrhages and illustrate the location and extent of such lesions.

Translation Challenges

As we saw in radiography, CAT scans also have multiple synonyms in French—e.g., un scanner (CT scan), une scanographie (scan), un TAC scan (CAT scan), un CAT/CT scan (CAT/CT scan), and une tomodensitométrie [TDM] (CT scan)—all of which correspond to the standard English “CAT scan” or “CT scan.” Note this list of French terms contains the English acronym CAT, a French version TAC, and the uniquely French acronym TDM. When translating DI reports, the number one rule is not to make assumptions. Specifically, the translator should expand all source acronyms, assess their meaning, and then determine if an equivalent exists in the target language. In the above example, one cannot simply refer to a “TDM” in the English translation because this acronym stands for a unique French term (une tomodensitométrie) that has no literal equivalent in English. This illustrates the importance of researching the correct terms in the source and target languages and avoiding the literal translation or direct transfer of acronyms from the source to the target.

Another example involves the structure of DI reports. These are typically divided into predictable sections in French and English: 1) Renseignements cliniques (History), 2) Technique (Technique), 3) Résultats (Findings), and 4) Conclusion (Impression). A very common translation error is to translate Résultats (Results) as “Results” and Conclusion (Conclusion) as “Conclusion.” While the reader would still certainly understand the meaning, these are not the standard English medical terms, meaning that the target would read as a “translation” rather than as a transparent and authentic text in its own right. In medical translation, it is essential to use the correct medical term—ideally, the one doctors use, because doctors are your target audience—not merely a translation that is comprehensible but clearly not proper medical terminology.

Similarly, difficulties often arise when translating normal findings between French and English. French reports often describe findings as sans particularité (without special findings), sans anomalie (without abnormalities), pas d’anomalie (no abnormalities), or pas d’anomalie particulière (no special abnormalities). In English, these are sometimes mistranslated literally, such as “without particularity” or “no anomalies.” Again, while the meaning would be understood, these would be considered poor translations because they do not reflect the language used by native English-speaking medical professionals. More accurate English translations include “unremarkable,” “no abnormalities detected,” “no significant findings,” or “normal.”

A Steep Learning Curve with Rewards

Radiography and CAT are common DI modalities, each with its own specialized vocabulary. Translators must invest time and effort in researching the correct terms for image description (i.e., “radiolucent/radio-opaque” versus “hyperdense/hypodense”). By building an understanding of the technical basics and differences between modalities, translators will have a better command of the terminology and enhance translation quality. While an initially steep learning curve is involved in these documents, translators should strive to do the extra research on the procedure and terminology in context. In other words, never make any assumptions regarding terms or acronyms, even if the cognate “seems” to be right. While translating these reports can be challenging, this is a potentially lucrative area of specialized medical translation and one with a relatively limited range of terminology, which means the investment of time and research can reap tangible rewards.

Tips for Translating Diagnostic Imaging
  • Double-check cognates. (Is this the right term in the target language?)
  • Beware of borrowed English terms and acronyms in the source (e.g., CAT versus TAC versus TDM in a French report).
  • Research medical terminology—word-level translation is often inaccurate!
  • Always expand acronyms before translating them (e.g., PDL ➔ produit dose longueur ➔ dose length product ➔ DLP).
  • Read imaging reports in your target language (not just the source) to identify medical writing practices (e.g., passive voice, personal pronouns, etc.).
Resource List


Maxwell, Robert W. Maxwell Quick Medical Reference, 6th Edition (Maxwell Publishing Company, 2012).

Pocket Medicine: The Massachusetts General Hospital Handbook of Internal Medicine, 5th Edition (LWW, 2013).

Tool Box for the Medical Translator (French>English)

University of Wisconsin Radiology Teaching Site

Radiology Assistant: Radiological Society of the Netherlands

Radiological Society of North America


Erin M. Lyons is a full-time French, Italian, Spanish, Swedish >English translator, medical writer, and consultant based in Paris, France. She is also an adjunct professor of translation at the University of Maryland and teaches digital entrepreneurship at the École Supérieure de Commerce et d’Économie Numérique. In 2016, she developed BabelNouvelle, a mobile-based translation technology employing crowdsourcing and machine translation to facilitate medical services in the developing world. She has a BA in Romance languages and literature from the University of Chicago and an MA in Italian and French translation from the Middlebury Institute of International Studies at Monterey. Contact:

Lori Newman is a freelance Chinese, French, and Spanish>English translator, editor, and veterinarian based near Boston. She specializes in veterinary and human medical translation and editing. She recently translated four veterinary clinical guides from Spanish into English for publication. She has a DVM from Tufts University, an MA in linguistics from the University of California, San Diego, and a BS in biochemistry from Brown University. Contact:

1 Responses to "Translating Diagnostic Imaging"

  1. Clara says:

    A radiologist has to constantly upgrade himself with technology and he has to be more patient-centric to become successful. Diagnostic Radiology as a subject has gained huge importance in the recent years with the increase in cancer-related treatments.

Comments are closed.

The ATA Chronicle © 2023 All rights reserved.