Key words
ultrasound - education - training - quality Assurance - imaging
1. Introduction
In 2006, the Education and Practical Standards Committee (EPSC) of the European Federation
of Societies in Medicine and Biology (EFSUMB) developed a set of minimum training
requirements [1] recommending structured theoretical and practical training for gynecological, obstetric,
gastroenterological, nephro-urological, breast, and vascular ultrasound (US). Three
levels of training and expertise were proposed, and a curriculum for each of the three
levels of training was developed for the many different fields of US application.
The paper also acknowledged that a systematic recording of findings of any US examination
in the patient records was mandatory.
In this paper (short version; the long version is published online), the EFSUMB describes
a concept of professionalism, which aims to make medical US a reliable professional
service based on common and uniform quality standards with respect to regular service
structures and management when US examinations are performed. This includes a relevant
clinical indication, followed by a thorough and structured US examination with reliable
and comprehensible storage of images/cine-loops and a clear systematic report.
The presented standards may appear demanding and not all US professionals currently
in practice may achieve them. Nevertheless, the EFSUMB is committed to the approach
of developing optimal rather than minimal professional standards with respect to exemplary
patient care.
Professional medical US practitioners in Europe, including physicians and non-physicians
who specialize in US, must all have completed comprehensive curricular training and
received formal approval by the different national regulatory authorities to comply
with legal regulations.
This EFSUMB position paper presents a common position across the different medical
professions within the EFSUMB regarding the optimal standards for the performing and
reporting of US examinations by any professional US operator regardless of where and
“who performs your scan” [2] and other variable conditions in the respective national health care systems.
2. Legal Aspects and Indication for Medical Ultrasound
2. Legal Aspects and Indication for Medical Ultrasound
All medical facilities providing US services, i. e., hospitals, doctor’s offices,
outpatient clinics, and other health service institutions, under whose legal responsibility
medical ultrasonography is carried out, are legally and ethically responsible for
the proper training of personnel to safely use equipment of appropriate quality with
an understanding of the limitations of medical ultrasound [1].
US devices are subject to a medical device regulation [3] and national implementation is undertaken under the Medical Product laws of the
individual countries, e. g. [4]
[5]. A special institution (notified body) within Europe certifies if the device is
in compliance with these directives before the product is sold. After a positive evaluation
the CE-mark is given with a 4-digit number to identify this notified body [6]. Additional information about the possible acoustic output of this device is also
integrated into this CE-mark evaluation.
The user can see two indices related to the active output: the mechanical (MI) and
thermal index (TI) that have to be displayed on the monitor. Depending on the individual
settings, these indices are changed online and should not exceed the maximum values
specified as “Good Practice” for the specific medical application. The ALARA principle
(as low as reasonably achievable) is always the best choice in unclear situations
according to a benefit/risk-analysis for all applications.
In any situation, US practitioners should follow the safety recommendations given
by national and international societies and their special committees [7]
[8].
Regular long-term certified maintenance of US equipment and transducers is mandatory
to ensure optimal function of the different US techniques. Maintenance should be performed
within the optimal standards described by equipment manufacturers.
Position Statement 1: Medical facilities are responsible for safety, legal aspects
of ultrasound services, and the regular maintenance of medical ultrasound equipment
(agree/disagree/abstain: 17/0/0).
As with any medical imaging procedure, an US examination should only be performed
for a reasonable medical indication. Although the risk is very low, the potentially
harmful physical effects of US energy on examined body tissues [9] must be taken into account when establishing the indication. The purpose, procedure,
limits, and complications of the US examination, particularly for invasive US-guided
procedures, for which informed written or verbal consent is required, should be explained
to the patient. “Preventive” whole-body US examinations of asymptomatic persons are
not recommended. They have no medical indication and are controversial as part of
a general health check, owing to incidental findings which may be of uncertain clinical
relevance and false-positive findings with potentially negative psychological, medical,
and economic effects [10]
[11].
Position Statement 2: Every ultrasound examination requires an appropriate medical
indication and justification (17/0/0).
3. Organization of Medical Ultrasound Service
3. Organization of Medical Ultrasound Service
In medical facilities dedicated to training doctors or other healthcare professionals
who perform ultrasound scans, such as university clinics, teaching hospitals, and
other medical training centers, departments, sections, or similar work units providing
medical US services should have a responsibility hierarchy. They should be managed
and headed by a responsible US practitioner with the highest level of expertise. The
organization of the US service must allow for continuous training, supervision, and
quality assurance of novices and practitioners with less experience. The most suitable
and beneficial manner in which this teaching and expertise development can occur is
the “mentoring” system, where two practitioners, one senior and one junior, take turns
performing scanning in the same room in order to ensure supervision, teaching, continuous
learning, and professional development to keep the diagnostic professional standard
of the staff stable over a long period.
Previous patient examination findings and clinical information should be available
to the examiners before starting any new patient examination. This applies to images
and written reports for diagnostic imaging – not only previous US exams but also other
relevant imaging (CT, MRI, X-ray, endoscopy, laboratory findings, etc.) – and the
patients’ clinical records. In a digitalized workflow this requires access to a Picture
Archiving and Communication System (PACS) and hospital information system in the US room.
Activities that can be delegated to (non-scanning) US assistants include all organizational
work regarding patient appointment scheduling, patient transport organization, patient
reception, in-department management of patients, examination preparation, environmental
maintenance and material supply organization, patient support to the examination couch,
and routine documentation.
Position Statement 3: Medical ultrasound services with a training mandate should facilitate
continuous training and mentoring, ideally delivered in teams of two practitioners
(16/1/0).
4. Medical Ultrasound Scanning Room
4. Medical Ultrasound Scanning Room
The spatial design of US rooms and departments should take into account the spectrum
and workload with respect to performed examinations and interventions. An efficient
workflow, adequate lighting conditions, compliance with hygienic working conditions,
and patient safety must be ensured through appropriate room design. Each examination
room should provide sufficient space for US equipment, stretcher and/or patient bed,
examiner, documentation station, disinfectant facilities, and must also allow for
emergency patient care. Intervention rooms require additional space for assistance,
intervention equipment, preparation and processing of biological material, resuscitation
equipment, and patient transfer (see [Fig. 1]). A working surface for sterile material, patient monitoring, oxygen supply and
infusion, as well as dimmable room lighting and a movable spotlight are preconditions
for US-guided interventions.
Fig. 1 Suggestions for the design of ultrasound examination rooms: A Minimal Ultrasound room for ambulatory patients only, approximately 17.5 m2. B Ultrasound room in a hospital enabling education in a two practitioner setting plus
assistant person, as well as complex interventions e. g. percutaneous catheter drainages
etc., approximately 45 m2. The light green rectangle marks the minimal space for medical ultrasound at all:
12 m2 = examination couch + 1 meter in every direction, required according to [13]. Both room concepts have minimal size in relation to the functions covered. Existing
architecture may not allow for such optimal use of space, and no space is considered
for more functions, e. g. anesthesia.
The space required for basic US examinations can be calculated by combining the modular
functional parts that are needed. For example, 25 m2 can provide one changing room for the patient and a desk for one practitioner in
an US room in a hospital. Or 17 m2 are enough for rooms for ambulatory patients only [12]
[13]. These are absolute minimal requirements. Below these limits, the lack of space
results in avoidable additional work steps with every patient, which have to be considered
during the entire period of use of the room.
The optimal size of an efficient US room, including two changing rooms, space for
a team of two US practitioners, plus one organizational/documentation assistant, to
enable complex interventions, may add up to e. g. 45 m2, excluding staff changing and restrooms. (For more details see the long version,
published online).
Position Statement 4: Specifically designed medical ultrasound rooms of appropriate
size are recommended for an optimally safe and efficient workflow (17/0/0).
5. Medical Ultrasound Hygiene
5. Medical Ultrasound Hygiene
Adequate preparation and cleaning of the transducer, US unit, and the examination
couch are required to avoid potential infection transmission [14]
[15]
[16]
[17]
[18]
[19]. Adherence to published protocols for the cleaning and reprocessing of medical US
equipment varies considerably among US practitioners worldwide and is disadvantageous
to good practice [20].
Guidelines for transducer and scan hygiene predominantly refer to the use of non-sterile
gel as a coupling agent [14]
[15]
[16]
[17]
[18]
[19]. The standard use of spray or liquid disinfectants, which are used to disinfect
the transducers before and after use, as coupling agents instead of gel can simplify
and shorten the examination. Care should be taken to ensure that only disinfectants
compatible with the transducer materials, as documented in the manufacturers’ guidelines,
are used. Disinfectant sprays and liquids specifically designed for disinfecting mucous
membranes (e. g., octenidine) may be superior to alcohol-based disinfectant coupling
agents because they form a lubricating layer on the skin for the transducer instead
of evaporating rapidly.
Position Statement 5: Hygiene plans and standards for cleaning and disinfecting ultrasound
equipment should be implemented for every ultrasound service with monitoring of compliance
(17/0/0).
6. Structured Medical Ultrasound Examination
6. Structured Medical Ultrasound Examination
US examinations should follow a predefined standardized scheme in which all relevant
organs and/or structures are imaged completely and systematically on two planes and
in different patient positions, if appropriate. In addition to normal organs and structures
relevant to the indication, all pathological findings should be examined with US when
encountered. Complementary US techniques such as Doppler US, elastography, and contrast-enhanced
ultrasound (CEUS) should be applied selectively, when necessary, to answer the clinical
question or to characterize pathological findings according to accepted practice guidelines
[21]
[22]
[23]
[24].
Algorithms with predefined transducer positions have been published for almost all
US applications, in particular for abdominal US [25]
[26]
[27]
[28]
[29], thoracic US [30]
[31], joint US [32], thyroid US [33]
[34], echocardiography [35], vascular US [36]
[37]
[38]
[39], and US-guided interventions [40]
[41]. If standard examination algorithms have not been published for a particular US
application, the US practitioner should follow an institutional or at least an individual
standardized examination scheme to ensure that it is retrospectively clear what was
examined and how.
Position Statement 6: A structured medical ultrasound examination based on standard
algorithms is recommended (17/0/0).
7. Acquisition of Medical Ultrasound Images and Cine-Loops
7. Acquisition of Medical Ultrasound Images and Cine-Loops
In institutions with a digitized workflow, the complete image bundle of any US examination
should be stored digitally, primarily as a DICOM dataset in the system, that ideally
covers the patient’s entire US examination. The raw data should be available for dedicated
software analysis if further processing of the dataset is required (e. g., CEUS or
volumetric post-processing). All single images, representative cine-loops, and/or
3 D volume datasets selected by the examiner to demonstrate his diagnostic conclusions
should be sent to the PACS unit.
The still images dataset must include:
-
all organs to be assessed on at least two, ideally perpendicular, planes, both showing
the maximal extension of the organ including measurements in 3 dimensions for volume
calculation, if applicable,
-
all pathologic findings on at least two, ideally perpendicular, planes, both showing
the maximal extension of the lesion/pathologic change including measurements in possibly
3 dimensions. In case of multiplicity of pathologic lesions, image storage may be
limited to a selection, showing the range of variety, including one or more typical
“reference lesions” with size/volume measured for follow-up purposes.
Video sequences should be used
for complete volume acquisition (sweep through a complete organ/region) for anatomical
representation of an organ/anatomical structure/pathology: The organ/lesion view should
be taken in only one steady sweep from outside of one margin to the outside of the
other margin, in a recognizable direction.
And for documentation of physiologic or pathologic dynamic phenomena (e. g., heart
action, fetal movements, bowel wall movements, blood flow, contrast enhancement, lung
sliding). The respective organ/structure should be taken with a transducer held still
in an adapted plane. The cine-loop should contain a representative time period [39].
3 D volume datasets
may replace cine-loops of steady sweeps through organs or pathologic findings obtained
for complete volume acquisition.
Labeling
Still images and cine-loops should be labeled with appropriate pictograms/terminology/abbreviations.
Topographic pictograms are better and more rapidly understood than written transducer
position labels, with the advantage of being independent of language differences.
Non-image information which must be provided with any still image or cine-loop includes:
Patient identification data, institution/examiner identification data, date and time
of the examination image or cine-loop.
Additional data to specify technical details of the exam:
US system/model, US transducer, frequency, mechanical and thermal index, and other
technical pre- and post-processing settings used, focus position(s), if applicable.
Position statement 7: Ultrasound images and cine-loops from all standard ultrasound
views and any abnormal finding should be stored and reported (16/0/1).
8. Medical Ultrasound Reporting
8. Medical Ultrasound Reporting
The main purpose of the written US report is to communicate findings, conclusions,
and the relevance to the clinical enquiry to the referring clinician. In medical facilities,
where patient records are kept electronically, US findings should be recorded, reported,
and archived electronically, too.
Beside patient identification data, each report should contain relevant information
about when, where, and by whom the examination was performed, for what indication,
and which equipment was used. Subsequently normal and pathological findings must be
documented in a systematic approach. Limitations of the examination quality and confidence
level should be indicated.
What to communicate to the patient during, or shortly after the examination, depends
on the circumstances of the examination.
For the communication of medical US results to the referrer and the patient file,
a structured report using standardized reporting templates is recommended. Structured reporting using
digital “report templates” standardizes and simplifies reports by sometimes exchanging
the sentences with short phrases and giving the examiner a chance to select different
options quickly [42]
[43]
[44]
[45]
[46]
[47]. Structured documentation is a promising approach to standardizing findings, improving
the overall reporting quality of various diagnostic modalities, and facilitating interdisciplinary
communication [48]
[49]
[50]
[51]
[52]
[53]. Referring physicians and US practitioners generally prefer structured reports over
free-text findings [54]
[55]
[56].
Inexperienced examiners can benefit from the use of structured documentation, as relevant
content and the naming of anatomical structures are indicated and the recommended
terminology is offered during the preparation of the report, thus serving as a checklist
for the examiner [47]
[55]
[56].
The US imaging spectrum is so large that recommendation of a single common “report
form” that covers all fields, is not possible. However, there are a number of mandatory
rules to follow ([Table 1]):
Table 1
Mandatory content of ultrasound examination reports.
|
1.
|
Institutional identification (name of hospital/practice/referring physician and investigator
identification)
|
|
2.
|
Patient identification (family name, first name, sex, birth date. Patientʼs address
may, in hospitals, be replaced by internal file number to relate patient data to medical
history and address data stored in central system: e. g. HIS)
|
|
3.
|
Date and time of US examination
|
|
4.
|
Relevant anamnestic and clinical information stating the indication for the examination
|
|
5.
|
Diagnostic question(s) to be solved by the US examination
|
|
6.
|
Scanning conditions and, if so, limitations of the examination, e. g., regions/organs
not seen
|
|
7.
|
Descriptions of US apperance of organs and pathologies
The report should describe image characteristics in grayscale or Doppler US using
standardized terminology, but not clinical diagnoses. It is advised to use text modules
for normal findings and frequent pathologies. The description should use these categories
for organs or structures: Position – Size – Shape – Contours – Echogenicity – Echo
Texture – Tubular Structures (vessels, ducts) – phase-specific enhancement pattern
with US contrast agent, relative stiffness with US elastography.
|
|
8.
|
Summary or interpretation including (suspected) diagnoses
Three parts are advised:
-
Answering the clinical question(s) raised
-
Listing other pathologic findings possibly in the order of their clinical relevance
(e. g., potential malignancies prior to simple cysts)
-
Closing remark about the remainder of the examined areas, excluding other abnormalities
in relation to possible limitations, e. g., due to unfavorable examination conditions
A cautious interpretation of images is advised to avoid potentially false conclusions.
Diagnostic statements should not predetermine the absolute diagnosis, e. g., “patient
has metastases”, but instead keep the relation to the method used: e. g., “typical
sonographic appearance of metastases”.
|
|
9.
|
Diagnostic and/or therapeutic consequences, possibly including suggestions for further
diagnostic workup or follow-up
Imperative instructions for further patient management within the examination report
derived from US findings may cause medicolegal problems if a recommended action is
not implemented by the clinically responsible physician. Therefore, considerations
regarding further medical management should be formulated as suggestions rather than
recommendations (e. g., not “surgery is necessary” but instead “surgery is worth considering.”
|
The text volume of an US report may range from summary notes in the patient’s file,
e. g. focused thoracic US: “No pleural effusion found on right side”, to very extensive
versions with recording of all cine-loops to be archived together with a detailed
report, with all nine categories, e. g., in second-trimester obstetric US screening,
the summary may be three to five pages long.
Position Statement 8: Structured ultrasound reporting and the use of templates and
text modules is recommended (17/0/0).
Communication of Medical US Findings
Selected relevant image material should be demonstrated, explained, and discussed
with the responsible clinician(s) as with all other imaging modalities. This may happen
via an inter-personal exchange between the examiner and referring clinician or in
multi-disciplinary clinico-radiological meetings. To influence immediate clinical
management, in cases of high clinical urgency, a verbal report highlighting the salient
findings should be given directly to the responsible clinician prior to issuing a
formal report or even better by clinician presence and involvement during the examination
of the patient.
The complete digitally stored medical US image material and the report should be available
for all clinicians involved in patient care. Depending on national regulations, the
patient and other medical personnel may also have access to the images and the associated
report of the US examination.
Position Statement 9: The digitally stored and reported medical ultrasound data should
be available for all involved parties in the patient’s care and should be communicated
in a timely manner (17/0/0).
9. Medical Ultrasound Data Management and Archiving
9. Medical Ultrasound Data Management and Archiving
DICOM (Digital Imaging and Communication in Medicine) has been established as a non-proprietary
standard for the storage, communication, and management of medical imaging information
and related data [57]
[58]. It is implemented in all modern medical US systems and, therefore, should be used
for digital documentation and archiving of medical US imaging. PACS (Picture Archiving
and Communication System) is the software solution that enables storage and reproduction
of any kind of medical DICOM imaging material and digital reports, which should be
used to archive and manage medical imaging data. Thus, US images and cine-loops are
available on an equal par with image files from other imaging modalities, allowing
demonstration in multidisciplinary meetings, direct comparison with findings from
cross-sectional imaging, follow-up imaging, the application of image-fusion techniques,
and the partial replacement of imaging involving exposure to radiation. However, PACS
use and implementation may be variable among countries for a number of different reasons
[59].
Position Statement 10: Digital image archiving of ultrasound examinations is mandatory.
In institutions use of the standard PACS is recommended (17/0/0).
10. Quality Considerations
10. Quality Considerations
Patients and referring physicians should expect to receive the best achievable quality
of medical US. As providers of medical US, the objective is to achieve a diagnostic
reliability level comparable to the level published in guidelines and other high-quality
review publications. Quality assurance reviews and maintenance of US equipment should
meet the accepted original manufacturer standards.
In comparison to other imaging modalities, US is more operator-dependent. This is
often perceived as a failure to examine the relevant area with the transducer or as
being the result of the region being obscured, e. g., by gas or bone. US examinations
can be as informative as other imaging modalities or even better and may even have
the advantage of superior spatial resolution, real-time live presentation, and the
ability to readily repeat the examination. It is vital that the target organ/region
is stored as an image or video file, because without this, there can be no re-evaluation
by a second expert. Every US practitioner must strive to achieve a level of imaging
reliability similar to other imaging modalities. An attempt should be made with US
to obtain images of all aspects of the target region/organ, to ensure that the examination
is reliable with respect to identifying or dismissing abnormalities. Where a full
examination is not possible, a thorough description of the regions/organs/aspects
that were not clearly imaged or where there was limited diagnostic quality should
be stated and the report should be written in a way that makes the limitations of
the examination clear. This applies in particular to part c) of the conclusion (table
1, 8.): the value of a summarizing statement regarding the other examined organs and
regions without pathologies not mentioned in parts a) and b) of the conclusion. For
example, “The remainder of the ultrasound examination demonstrated no findings of
clinical significance” must be put into perspective by an indication of any patient-specific
or methodological limitations of the examination of these organs and regions.
US diagnoses in parts a) and b) of the report’s conclusion should be formulated as
precisely and definitively as possible, but in a patient-specific manner, with relevant
differential diagnoses taken into account. To minimize loss of examiner reputation,
even the most typical sonographic appearance should only be referred to as such: e. g.,
“typical sonographic aspect like liver metastases”, not just “liver metastases”.
In order to be able to obtain pooled statistical data for quality assurance of a medical
institution and its qualified US practitioners (sensitivity, specificity, positive/negative
predictive value, and overall accuracy of US diagnoses), it is necessary to classify
the final diagnosis correctly according to the International Classification of Diseases
(ICD). Currently, there are a number of medical diagnostic procedures with mandatory
national quality databases, e. g., endoscopic US, and US departments can benchmark
against these national standards. It is recommended to perform quality assurance as
a regular activity in order to confirm the practice quality and be compared to other
institutions.
Position Statement 11: Regular critical review of medical ultrasound reports is recommended
(16/0/1).
11. Conclusion and Future Perspectives
11. Conclusion and Future Perspectives
The practice of medical US still varies considerably in the areas of procedure, image
storing, and reporting. Most practices will have some areas where they could improve.
In this manuscript we have described the areas that the EFSUMB considers to be an
optimum standard for all US practitioners to attain. Practitioners should also be
aware of existing guidelines and position papers, to continually assess and improve
their US practice.
The ability to store and share US images and videos in a standardized digital database,
co-joined with a report from the operator, is crucial to improve the applicability
and clinical yield of this modality, in terms of economic value, quality, and educational
value. Adhering to these standards makes US examination a more reliable, reproducible,
and standardized imaging modality in line with other cross-sectional imaging methods.
With large datasets becoming available, US may benefit in the near future from deep
learning artificial intelligence solutions that could help to improve implementation
of unified standards and quality, thereby helping US practitioners to scan and report
readily, precisely, and accurately [60].
With a standardized approach, there are also better opportunities for appropriate
reimbursement and the timing of equipment update or renewal.
