Ultrasound Exams, who Should Perform them and how Should they be Documented?

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The Danish Society of Diagnostic Ultrasound (DSDU) is a multispeciality society whose primary purpose is to spread the use and knowledge of US. It is not a governing body but an advisory society with policies and recommendations.

Over the years our policy concerning who should perform ultrasound (US) has been that it should be a well trained medical person. In that policy we have always stated that whoever performs the examination also interprets it and writes the report. This policy was formed in the early days of US when image documentation was of relatively low quality and limited to still images. Today, still images and live clips may be stored digitally with no loss of quality and we found it relevant to reevaluate the above policy.

We were inspired by the work of Lasse Thorelius who has developed Sonodynamics (see http://www.sonodynamics.com). As a group we were invited to visit the department in Linnköping, Sweden, and see Sonodynamics in use. Very briefly, the concept of Sonodynamics is that an exam has a protocol with a predefined set of still images and live clips (sweeps). The sum of still images and live clips ensure that all US information of the examination region is recorded for subsequent evaluation/re-evaluation. Lasse Thorelius uses this for quality control (older colleague checks younger colleague) and for production where the radiologist interprets the exam which was carried out by a non-physician trained to perform the standardised exam.

As an example, Lasse Thorelius (in Denmark) writes reports on parts of the US production in Linnköping from image information received electronically.

After the visit, a group was formed under DSDU to work with possible implementation and recommendation of standardised exams in Denmark. As a primary task the group was asked to draft a paper describing DSDU’s policy concerning documentation of US exams and who should perform them.

The group continues its work with standardised exams. Standardisation of a number of well defined US exams each with a predefined set of still images and live clips will in the group’s opinion increase the quality of US, facilitate training and to some degree make re-evaluation possible. We wish to thank Lars Thorelius for his inspiration. The following text was approved by all members of the group and subsequently also by the board of DSDU.

Ultrasound Exams

Ultrasound (US) imaging resembles other sectional imaging modalities in that it is advantageous to apply standardised sequences of scanning positions so that the whole region of interest is investigated. An additional quality of US is its real-time nature which adds a dynamic element to the images – an element which may be compared to a clinical examination or an endoscopic procedure such as gastro-, colo- or cystoscopy.

An US examination typically consists of a systematic scanning of the relevant region followed by a focused investigation of possible abnormal imaging findings. The focused part may include varying degrees of transducer pressure in order to investigate the elastic nature of a lesion, to detect possible tenderness or to see fluid movements. Varying levels of inspiration and different patient positions may positively influence image quality and diagnosis. The procedure may be supplemented with Doppler studies, elastography or contrast investigation. Finally, interventional procedures may add further diagnostic information and therapy to the examination.

All the scanning information combined with the background knowledge that the investigator has about the patient (signs and symptoms, previous diseases, operations, blood tests, other imaging findings, previous US examinations) is the combined information that forms the basis for the interpretation of the US examination. This interpretation is made in writing – the US report.

In the Danish Society of Diagnostic Ultrasound (DSDU) our policy is that it is the investigator (the person performing the US examination) that makes the interpretation of the US examination and therefore also writes the US report. We cannot recommend a scenario where the US examination (image acquisition) is performed by one person and the subsequent interpretation (based on still images and live clips) and report is made by another person. In our opinion such a scenario will allow important information to be lost – especially concerning the focused part of the examination.

Who Should Perform the US Examination?

To perform and interpret US examinations and write the subsequent report requires a high level of expertice. Ideally, all US examinations should be performed by specialised physicians with US expertice as well as clinical expertice in the diagnostic situation. That is, however, not feasible since the demand for US examinations is much higher than the capacity of specialised physicians. It has therefore proved necessary to allow for non-physician scanning, which has been successfully implemented with no apparent loss of quality. In Denmark, it is a tradition at many departments to use sonographers within well defi ned areas of diagnostic US. A requirement is, however, that a physician trained in US is present to supervise. We do not have an offi cial sonographer education in Denmark, and education has therefore taken place at local hospitals – typically as training of radiographers, nurses or midwives. The training of physicians in the use of US is well established in radiology, gynecology, and cardiology. Moreover, we are seeing rising interest in US in other specialities that wish to use the US examination alongside the clinical examination, e.g. surgery, gastroenterology, orthopedics, rheumatology, anaesthesiology.

In Denmark, it is principally the decision of the single department, specialty or society how to implement US. In DSDU we encourage that this implementation involves thorough education of all investigators and that training is maintained through continuing education. One of DSDU’s important tasks is therefore to offer a wide spectrum of US courses. In addition, EFSUMB has made a praiseworthy eff ort in this context by defi ning training requirements (Minimum Training Recommendations for the Practice of Medical Ultrasound in Europe), which are available at http://www.efsumb.org.

How Should US Examinations be Documented?

The former scanning and documentation techniques involved reading images on the US monitor during scanning. The investigator could print selected still images on paper or transparancies. Today, on the other hand, it is possible with all newer equipment to save live clips as well as still images digitally for later evaluation or reevaluation. The evaluation may be performed on the US machine, via a mini-PACS or via a larger radiological PACS.

This development has several advantages. It is possible to check investigators in training, fi ndings may be stored for later comparisons or fi ndings may be sent to colleagues for conference/second opinion.

In DSDU, we do not have recommendations on what image information should be stored from an US examination. At present this may vary from department to department depending on local profi les in education and research. DSDU does, however, recommend that as a minimum all pathological fi ndings, as well as interventional procedures, are documented with still images. If the fi ndings or interventional procedures are of a dynamic nature, we recommend that documentation includes live clips if possible.