Several studies have reported on the use of ultrasound to teach anatomy to medical students.1-9 Three of these were published as abstracts only,4-6 three focused on echocardiography,3,7,9 and all except two7,9 attempted to teach students to acquire basic sonographic imaging skills as well as anatomy.Although the vast majority of students in all studies evaluated ultrasound as a useful learning tool for reinforcing anatomy and enjoyed the practical hands-on experience, some limitations were noted including large group size restricting access to equipment1,2 and the limited availability of places (less than 20% of the class cohort in two studies).4,7Using ultrasound to reinforce anatomy appears to be educationally worthwhile but equipping medical students with basic ultrasound skills to achieve this, whilst a laudable goal, has some drawbacks. It is labour and resource intensive requiring time, appropriate numbers of trained supervisors, and sufficient equipment to teach small groups. There is also the potential danger of sending the wrong message: ultrasound imaging is highly operator dependent and it often takes months or even longer to become proficient. It is arguable just how much \"...students acquire the skills to perform and interpret ultrasound...\" in short sessions where they are also focusing on learning normal anatomy.6 This concern also has an ethical dimension since it is possible that a student who volunteers to be examined might be prompted to do so because of a personal health concern and be falsely reassured by a \"normal scan\". Unless ultrasound imaging is vertically integrated into the curriculum allowing students enough time and exposure to develop their skills 10 it is unlikely that these obstacles will be overcome.Ivanusic et al (2010) reported using an alternative approach consisting of a 1-hour echocardiography demonstration performed by an expert examining a student volunteer with images projected to the remainder of the student group.7 This was highly rated by the students who commented that it reinforced lecture material in a stimulating way and demonstrated clinically relevant anatomy. Recently, Griksaitis et al (2012) reported a similar but shorter (30 minute) class demonstration to teach cardiac anatomy; they took the precaution of screening the student volunteer prior to the demonstration.9As in many other institutions, we use modern imaging techniques (computed tomography [CT], magnetic resonance imaging [MRI], endoscopy videos etc) to supplement and reinforce the teaching of clinical anatomy. In 2008, we introduced a single ultrasound demonstration session to third year medical students. The popularity of this session encouraged us to retain it and this report describes our experience to date.Methods A single 1-hour ultrasound demonstration of living anatomy was delivered to third year medical students (class size = 240-260) in 2008, 2009, and 2011 (in 2010 an abdominal body painting session was trialled in its place). In 2008, attendance was entirely voluntary but, after positive student feedback, the demonstration became a scheduled class activity. The session was timed to coincide with the end of a regional and clinical anatomy module which is in the latter part of the academic year and precedes the students moving to ward-based learning in years 4 and 5 of the curriculum. An experienced medical sonographer (LD) gives a brief introduction on the properties of transmitted sound waves, image orientation, the safety of ultrasound and its advantages, limitations, and clinical applications. The sonographer then demonstrates selected anatomy in the abdomen, pelvis, and neck in a consenting young, slim, female volunteer (a paid actress). The actress is scanned in the week prior to the demonstration in order to exclude pathology and to ensure that she is comfortable with the scanning process. She is instructed to attend the demonstration with a full bladder and having fasted overnight (the demonstration is held at 9 am). Sonographic images are projected on to a large lecture theatre screen (Figure 1). Two clinical anatomists (MDS and LS) provide commentary and encourage interactive questioning from the student audience. High resolution ultrasound images are obtained using an ACUSON Antares™ Premium Edition machine (Siemens Medical Solutions, CA, USA) equipped with a CH2-6 curvilinear transducer (2.86-3.33 MHz) for abdominal imaging and a VF13-5 linear transducer (10 MHz) for scanning the neck and anterior abdominal wall. The scanning sequence begins with the pelvis, after which the model takes a break to empty her bladder, and then scanning continues with the abdomen and neck. Table 1 lists the structures that are demonstrated. Colour Doppler is used to show blood/fluid flow (Figure 2) and typical arterial and venous waveforms. Figure 1. Organisation of the ultrasound demonstration session. Sonographic images are projected on to a large lecture theatre screen (lighting is reduced to enhance viewing). Table 1. Anatomical structures demonstrated by ultrasound Region Structures demonstrated Pelvis - uterus (including the endometrium and phase of the menstrual cycle) and cervix - ovaries (with follicles) - rectouterine pouch - bladder (including ureteric peristalsis and urine flow into the bladder) - external iliac and femoral vessels (emphasising the surface marking of the latter) Abdomen - rectus abdominis muscle and rectus sheath with epigastric vessels (the inferior epigastric artery being traced from its origin from the external iliac artery near the deep inguinal ring) - liver (right and left lobes, portal vein, hepatic artery and veins) and diaphragm - gallbladder and extrahepatic bile ducts - spleen - kidneys (including measurement of length) - pancreas - abdominal aorta (including origin of the celiac trunk and superior mesenteric arteries) and inferior vena cava - renal vessels - gut peristalsis (and the difficulties of imaging the normal appendix) Neck - carotid sheath - thyroid gland Figure 2. An example of 'living anatomy'. A transverse section of the bladder with a peristaltic jet of urine shown by colour Doppler At the end of the first ultrasound demonstration in 2008, students were invited to complete an anonymous questionnaire evaluating the session using a five-point Likert scale to grade responses, with responses ranging from grade 1 (excellent) to grade 5 (very poor). Questionnaires were collected by a student representative and analysed independently by the University of Otago Higher Education Development Centre. Results 152 questionnaires were returned, a response rate of at least 63% (attendance in 2008 was voluntary and the maximum possible class size was 240). Ratings are summarised in Table 2. Overall, responses were extremely favourable, with more than 90% of respondents considering that the session had stimulated and improved their understanding of anatomy. Free text comments were overwhelmingly positive and included statements such as \"a good introduction to using ultrasound\", \"good to have combination of different backgrounds of demonstrators\", \"awesome to see organs in the living body\", \"puts anatomy in context\", and \"good to get the exposure to a clinical technique we haven't seen much of yet\". There were a few negative comments such as \"everything looks like shades of grey\", \"the class size was too big to encourage questions\", and \"I couldn't see where the probe was on the subject\". Finally, a few students commented that they would like to see the heart, a pregnant patient, or a male subject. As a measure of the success of the session, third year medical students voted it the best teaching innovation for 2008. Table 2. Summary of student responses to the evaluation questionnaire (n = 152) Questions Grade 1 & 2 (very positive and positive) Grade 3 (neutral) Grade 4 & 5 (negative) 1. Overall, how valuable was this session for you? 95% 4% 1% 2. Did this session stimulate your interest in anatomy? 91% 7% 3% 3. Did the session improve your understanding of abdominal/pelvic anatomy? 82% 14% 4% 4. Did you like the interactive style of presentation? 94% 5% 1% 5. Was the session well organised? 95% 4% 0% 6. Do you think this approach is useful as an aid to learning the clinical relevance of anatomy? 97% 2% 1% 7. Would you like to see this session repeated within future Regional & Clinical Anatomy modules? 98% 1% 1% 8. What did you like best about the session? Free text responses (see text) 9. What did you like least about the session? 10. Any other comments Discussion Using ultrasound imaging to supplement other methods of teaching anatomy offers several opportunities. Firstly, it allows anatomy to be visualised in real time enabling students to appreciate dynamic aspects such as blood flow, peristalsis, and how anatomy may be influenced by respiration, posture, and body fat. Secondly, it underlines the clinical application of anatomical knowledge, particularly when structures are demonstrated by an expert who is using the same technique in everyday clinical practice. Thirdly, it complements standard anatomy teaching by emphasising clinical aspects such as renal length which often receive little attention when learning anatomy. Finally, it may help to emphasise the importance of human anatomical variation. 8 We deliberately introduced this session after students had completed the bulk of their anatomy learning in anticipation of them integrating the clinical real-time sonographic imaging with their existing knowledge gained from dissection, prosections, models, body painting, radiography, and cross-sectional imaging (CT and MRI). We were not aiming to teach students how to perform an ultrasound scan. Instead, we wanted to introduce them to this safe, non-invasive and widely available imaging technique with its unique strengths and weaknesses and enhance their learning of anatomy in the process. Previous studies reporting the use of ultrasound to teach anatomy to medical students are shown in Table 3,1-9 which summarises the structure of each course, study subjects and anatomical regions studied. We chose a class demonstration with a hired model for a variety of reasons. Logistically, we had neither the resources nor manpower to offer hands-on training. A high-quality ultrasound machine equipped with a range of transducers was used to provide images of optimum resolution, rather than relying on potentially inferior images displayed by smaller portable machines used in other studies.3,7,11,12 It is well known that the yield from ultrasound is highly operator dependent. Therefore, demonstration by a skilled expert should be more rewarding and using an actor/actress also removes any ethical dilemmas or anxiety surrounding the use of student volunteers (both the potential to discover pathology and that of providing false reassurance from a 'normal scan' done by a novice). Although the students rated the session highly, sonographic visualisation of anatomy in this way does have limitations. The orientation of the image can be difficult to conceptualise when moving between structures and regions and students are denied hands-on experience. We only evaluated learning by asking the students to what extent the session had improved their understanding of anatomy. Consequently, we addressed Kirkpatrick's first level of effectiveness (reaction) but did not attempt to quantify the learning opportunity or its impact on the application of anatomy (behaviour and results).13 The positive wording of our questionnaire may have introduced a bias toward favourable responses. We would agree with Ivanusic et al. (2010)7 that ultrasound is best used to highlight specific anatomical features or concepts and used as an adjunct to other methods of teaching anatomy (including cross-sectional imaging), rather than as a substitute for these. Interestingly, first year medical students in the UK randomised to learning gross cardiac anatomy by either cadaver prosections or a live echocardiography demonstration showed similar educational performance scores;9 unfortunately, the authors did not investigate the educational utility of combining these approaches. Finally, our demonstration was restricted to the abdomen, pelvis, and neck but we are interested in extending this to include echocardiography as others have done.3,7,9 Ultrasound imaging has been reported in other educational contexts other than primarily as an adjunct to teaching anatomy to medical students. For example, Talarico (2010) 14 from Indiana made reference to ultrasound examination of cadavers during the delivery of a non-medical anatomy course and Zumwalt et al (2010)15 at Boston University School of Medicine described how radiology residents spent about 20-30 minutes teaching senior medical students how to use an ultrasound machine during a radiology module. Other undergraduate medical programs have focused on ultrasound imaging in the emergency room,16 in assisting physical examination of the heart,17 liver,18 abdomen,11,19 or neck,8 or simply to provide a primer in basic ultrasound technical skills.20 Table 3. Summary of previous studies reporting the use of ultrasound to teach anatomy Author Institution Medical Students and Mode of delivery Study subjects Study region Teichgräber et (1996)1 Hannover Medical School, Germany First year Up to 10 students per US machine Introductory lecture + 2 or 6 hour seminar. Hands-on Student peers Abdomen and pelvis Heilo et al (1997)2 University of Oslo Medical School, Norway Second year Groups of 15 students (up to 8 per machine); 1-2 hours. Hands-on Student peers Abdominal viscera, thyroid, and forearm Wittich et al (2002)3 Mayo Medical School, Minnesota, USA First year Introduction (1.5 hour), small group training (1 hour), independent practice (mean 14 mins). Hands-on Student peers Cardiovascular Wicke et al (2003)4 University of Vienna, Austria Groups of 6-7 undergraduate students of variable seniority 10 weekly 3 hour sessions. Hands-on Student peers Abdomen and pelvis Tshibwabwa and Groves (2005)5 McMaster University, Ontario, Canada First year Groups of 6 students. 3 x 1.5 hour sessions. Hands-on Not stated Cardiovascular and renal Tshibwabwa et al (2007)6 McMaster University, Ontario, Canada Second year Groups of 6 students. Hands-on Duration of sessions not stated. A normal \"control model\" Upper and lower limbs (musculoskeletal) Ivanusic et al (2010)7 University of Melbourne, Australia Second year 1 hour demonstration by clinicians Images projected to class of 22 students Student volunteers