Complaints Involving Sonographers: What Three Decades of Cases From A Public New Zealand Database Can Teach Us.

The authors have nothing to report.

The authors have nothing to report.

The online HDC database [ 3 ] was searched on 30 September 2025 for all cases including the term ‘sonographer’. The cases were independently extracted and cross‐checked by three authors (M.N., C.C., A.H.) and reviewed in detail by all six authors. Cases were included if the sonographer played a direct role in the case and was investigated by the HDC. Cases were excluded if the sonographer was mentioned only peripherally and played no direct role in the case, or if the sonographer was not under investigation. Cases were tabulated and analysed according to: number of cases per year, case setting (private practice versus public sector), case complexity, case circumstances, outcome of the complaint, expert opinion, and sonographer response to the complaint. Ethics approval was not required as this study accessed and analysed publicly available anonymised data.

At the time of the HDC database search [ 3 ] on 30 September 2025, there were 1846 published cases with 53 containing the term ‘sonographer’. The sonographer was under investigation in only 15 cases. The search strategy and distribution of HDC decisions is provided in Figure  1 . The number of cases varied over the 31‐year period from 0 to 5 cases per year (Figure  2 ) averaging 1.5 cases per year in the last decade. An increase in the number of cases was observed in the last 10 years (Figure  2 ). A summary of the cases is provided in Table  2 . Health and Disability Commissioner (HCD) decisions breakdown. Number of cases per year with a 10‐year moving average trend line. List of HDC cases directly involving the sonographer, listed chronologically from most recent. 22HDC 01223 23HDC 00906 21HDC 00168 17HDC 00453 18HDC 00279 16HDC 01852 16HDC 01486 15HDC 00464 15HDC 00309 15HDC 00881 15HDC 01413 16HDC 00455 15HDC 01258 14HDC 00558 Abbreviations: bHCG, beta human chorionic gonadotropin; BMI, body mass index; CPAM, congenital pulmonary airway malformation; CS, caesarean section; FNA, fine needle aspiration; HDC, Health and Disability Commissioner; HIE, hypoxic ischaemic encephalopathy; IVH, intraventricular haemorrhage; MCDA, monochorionic diamniotic; NICU, neonatal intensive care; TGA, transposition of the great arteries; TRAP, twin reversed arterial perfusion; TTTS, twin to twin transfusion syndrome. Public health service. Private health service. The majority of HDC investigations ( n  = 11, 73%) involved sonographers working in the private sector, with a ratio of private to public sector complaints of 2.8:1. In comparison, the ratio of sonographers currently working in private versus public sector is only 1.4:1 [ 16 ]. Hence, private sonographers were significantly over‐represented in the complaints. In terms of clinical applications, nearly all cases were obstetric ( n  = 14, 93%), with only one exception involving neck ultrasound. In five cases (33%), the sonographer was found in ‘breach’ of The Code. Two of these cases involved the same sonographer. Therefore, the number of sonographers who were found in breach of the Code is only four. In four cases (27%) the sonographer received an ‘adverse comment’, in one case (7%) ‘other comment’, and in five cases (33%) no comment. In total, the HDC raised concerns regarding the sonographer's practice in nine out of the fifteen cases (60%). The summary of these cases and key findings is provided in Table  3 . Cases in which the HDC raised concerns regarding the sonographer's practice. Congenital foetal anomaly not detected CPAM Congenital foetal anomaly not detected renal agenesis, absent bladder, anhydramnios Congenital foetal anomaly not detected TGA Incorrect terminology used and congenital foetal anomaly not detected: MCDA twins with TRAP Required component of the examination was not completed transvaginal ultrasound in early viable pregnancy Required component of the examination was not completed transvaginal ultrasound in early viable pregnancy Required component of the examination was not completed papillary thyroid cancer Abbreviations: CPAM, congenital pulmonary airway malformation; MCDA, monochorionic diamniotic; TGA, transposition of the great arteries; TRAP, twin reversed arterial perfusion. The most common issue was an undetected congenital foetal anomaly such as CPAM, renal agenesis (and associated abnormalities), transposition of the great arteries (TGA), low‐lying placenta, and twin reversed arterial perfusion (TRAP). In one case, the sonographer did not examine a palpable lump which later proved to represent a papillary thyroid cancer. In two cases, the sonographer did not extend the examination as recommended in commonly accepted guidelines [ 4 , 17 ]. One case involved a false positive diagnosis of ectopic pregnancy. Root cause analysis revealed that six of the nine cases (Cases 2, 3, 7, 11, 12 and 15) revolved around the sonographer performing a suboptimal examination and/or examination that did not adhere to accepted guidelines. In one case, the sonographer forgot to assess for a low‐lying placenta (Case 8). In another case, the examination was of acceptable quality, but the ultrasound was misinterpreted (Case 14). Finally, in one case of a TRAP syndrome, the sonographer was criticised for the use of incorrect terminology (‘single sac’) to describe a monochorionic pregnancy (Case 10). The sonographer did not appreciate the presence of TRAP on two examinations despite using colour Doppler, but recognised this on the third examination at 24 weeks. The HDC did not criticise the sonographer for the delayed TRAP diagnosis because reasonable effort had been made. Nearly half the cases (44%) involved a rare congenital foetal anomaly. The sonographers' responses to the complaints were broadly characterised by acceptance of responsibility, sadness, regret and apology in eight of the nine cases. In one case (Case 15), the HDC found the sonographer's professional attitude to be suboptimal. This case represents a notable exception worthy of closer examination. In Case 15, a patient was referred for an examination of a ‘palpable neck lump’ in the region of the thyroid gland and the clinician requested a ‘thyroid ultrasound’. The sonographer examined the thyroid gland and found nothing suspicious. The surrounding areas, palpable lump and lymph nodes were not examined. The patient continued to complain about the lump. Two and a half years later, a radiologist examined the lump and performed a fine needle aspiration. Histology revealed papillary thyroid carcinoma. In response to the complaint, the sonographer claimed that he simply performed the requested (thyroid) examination as instructed and further argued: ‘I am unaware of any protocol within the company which deals specifically with requests by patients to scan areas at variance with those requested by the referring clinician. I personally do not scan areas at the behest of the patient’. The employer, an industry expert and the HDC were critical of the practitioner's attitude. The employer emphasised that the company policy ‘encourages sonographers to answer the clinical question’ (in this case to determine the nature of the palpable lump) and that the company expects sonographers to act as ‘health professionals in their own right’. The expert added: ‘if a lump is mentioned on the request or by the patient, this should be scanned and correlated’. The HDC agreed, issuing the decision of ‘breach’.

The number of HDC complaints involving sonographers is extremely low given the high volume of examinations that sonographers around the country perform. Whilst the exact number of ultrasound examinations performed by sonographers in New Zealand has not been published, some reasonable estimates can be made. According to Health New Zealand | Te Whatu Ora, as of November 2024, there were a total of 579 full‐time equivalent (FTE) sonographers in New Zealand spread across private ( n  = 341, 59%) and public ( n  = 238, 41%) services [ 16 ]. Considering a typical case load of 14 cases per sonographer per day, half a day of non‐clinical time per week, and 5 weeks of annual leave per year, the total number of examinations performed by the workforce can be estimated at 1.7 million examinations per year. Under these assumptions, concerns regarding sonographer practice were identified in HDC complaints with an estimated frequency of one per 1.9 million examinations per annum (1.7 million examinations per year/1.5 complaints per year/0.60). While these are broad approximations, they illustrate the high quality of service that New Zealand sonographers deliver. This is further supported by several recent studies which demonstrate that sonographers seldom commit errors, and when errors occur, they are comparable in number and severity to errors made by radiologists [ 10 , 11 , 12 , 13 ]. As a result, the routine involvement of radiologists in the interpretation and reporting of ultrasound examinations has been questioned [ 10 , 11 , 12 , 13 ]. According to the MRTB, it is the sonographer's responsibility to ‘conduct, interpret and communicate the findings of the examination to other health professionals’ [ 4 ]. The radiologist is usually not directly involved in ultrasound examinations that are performed by the sonographer [ 14 ]. Although there is no legislative requirement for a sonographer to work in collaboration with a radiologist, this is the most common practice both in the public and private sector [ 13 ]. Typically, the sonographer performs and interprets the examination and summarises the findings for the radiologist either in a formal report [ 10 , 11 , 12 ] or a hand‐written worksheet [ 14 ]. The radiologist then reviews the sonographer's findings and authorises the final report. According to The Royal Australian and New Zealand College of Radiologists [ 5 ], ‘there must be the ability to review images with the clinical radiologist, preferably during the course of the imaging procedure’. In practice, this rarely happens [ 14 ]. Indeed, in none of the HDC cases did the radiologist personally attend the examination, even when the radiologist was available, on site, and even when the examination was difficult, evidently suboptimal, or the findings were questionable. This highlights the reliance of the radiologist on the technical skill and diagnostic interpretation of the sonographer. Whilst the sonographer–radiologist relationship must be underpinned by collaboration [ 5 ] and mutual trust [ 13 ], it also requires critical review of the sonographer's work by the radiologist and verification of the findings (in person) if required [ 5 ]. Unfortunately, such review was lacking in the HDC cases. This may be due to inattention of the radiologist, over‐reliance on the sonographer, or a lack of competence on part of the radiologist in a given ultrasound subspecialty. For instance, in Case 12, the radiologist openly admitted that his experience in obstetric ultrasound ‘was limited’ because he was trained overseas where obstetric ultrasound is performed in obstetric departments rather than in radiology. Despite lacking competence in this subspecialty, the radiologist signed off the sonographer's report anyway. In another case (Case 7), the radiologist authorised a staggering 462 reports per day (approximately 1 case per minute) which would not allow for meaningful review of the sonographer's work. There were other instances where the sonographer did not recognise a finding, but the recorded images captured the finding, hence presenting a unique opportunity for the radiologist to identify and diagnose the finding (Cases 2, 3, 8). Such opportunities were not realised and the non‐detection was propagated by the radiologist into the final report. These cases emphasise that when sonographers and radiologists work collaboratively, both practitioners must possess adequate diagnostic expertise, maintain vigilance, and be aware of unusual or rare pathologies as these featured frequently in complaints. When a sonographer and radiologist work collaboratively and the radiologist reports on the sonographer's findings, the radiologist bears joint responsibility for errors made by the sonographer. Whilst some diagnostic errors are potentially detectable by the radiologist, many are not. Specifically, the radiologist has no way of ascertaining the presence of a finding that had not been detected or adequately imaged by the sonographer (Cases 2, 7 and 15). The radiologist remains responsible for the final report [ 5 ] even when the imaging findings presented to the radiologist by the sonographer are mischaracterised (Cases 3 and 14). For instance, in Case 3, the sonographer recorded an image and applied the label ‘bladder’ where no bladder was present. In Case 14, both the supervising sonographer and the radiologist were influenced by a trainee sonographer who firmly believed she saw a live ectopic pregnancy. This resulted in an unnecessary operation and an excision of a normal fallopian tube in a patient with an early live intrauterine pregnancy. The radiologist–sonographer relationship can be problematic for the radiologist and also for the sonographer. For instance, in one recent study, the involvement of radiologists in the authorisation of obstetric ultrasounds had a detrimental effect on the quality of the reports when compared with reports issued independently by sonographers on the same cohort of patients [ 10 ]. In another study, sonographers outperformed radiologists in the characterisation of thyroid lesions [ 18 ]. Regardless of the diagnostic skill of the sonographer, the radiologist usually has the authority to override the sonographer's opinion and issue a report containing discrepancies or de novo errors [ 12 ]. Since the sonographer and radiologist are jointly named on the final report [ 9 ], the sonographer may be named on a report containing conclusions with which the sonographer disagrees. The shared responsibility for the final report does not apply when either the sonographer or radiologist performs and reports the examination independently. Interestingly, there was no single HDC case involving an independently reporting sonographer. It is not known how many examinations per annum are independently reported by sonographers, but such practice is common in New Zealand and has been in place for over 20 years [ 13 , 19 , 20 ]. For instance, at Waikato Hospital, approximately 6000 vascular examinations per year are issued independently by sonographers without the involvement of radiologists (pers. comm., Bridget August, charge vascular scientist, September 2025) and a further 6000 obstetric reports are issued by sonographers directly to obstetricians in antenatal clinics, which are later signed off by radiologists, often without modification and sometimes after the baby had already been delivered (pers. comm., Wendy Wackrow, charge sonographer, September 2025) [ 12 ]. The reason why no single case involving an independently reporting sonographer has ever been investigated is unknown. It is also possible that sonographers working in reporting roles may possess higher levels of skill and expertise and may therefore be able to avoid the errors that typically lead to HDC complaints. Based on the review of the HDC cases, the following practice points may assist sonographers in avoiding adverse outcomes for their patients and resultant complaints: Adhere to standards of practice, professional guidelines and department procedures. Maintain competence through continued professional development. Be mindful that sonographers working in private practice are overrepresented in HDC complaints. Be especially vigilant in obstetric cases. Use formal terminology when communicating ultrasound findings. Focus on answering the clinical question, not just following the prescribed protocol. When the exam complexity or technical difficulty significantly impacts on the quality of the examination, such considerations must be recognised and reported. Both the sonographer and the radiologist must have sufficient technical and interpretive expertise in the examinations they are performing and reporting. Urgent or unexpected findings must be communicated to the referring clinician without delay and health providers must ensure the message reaches the intended recipient. Perform regular audits of sonographers and radiologists to ensure their diagnostic performance is accurate and compliant with professional guidelines. Whenever possible, such audits should compare the sonographer's and radiologist's diagnostic opinion against patient outcomes. Comparing the sonographer's report with the report of the radiologist is not an effective audit strategy because radiologists make a comparable number of errors as sonographers [ 10 , 11 ]. Adhere to standards of practice, professional guidelines and department procedures. Maintain competence through continued professional development. Be mindful that sonographers working in private practice are overrepresented in HDC complaints. Be especially vigilant in obstetric cases. Use formal terminology when communicating ultrasound findings. Focus on answering the clinical question, not just following the prescribed protocol. When the exam complexity or technical difficulty significantly impacts on the quality of the examination, such considerations must be recognised and reported. Both the sonographer and the radiologist must have sufficient technical and interpretive expertise in the examinations they are performing and reporting. Urgent or unexpected findings must be communicated to the referring clinician without delay and health providers must ensure the message reaches the intended recipient. Perform regular audits of sonographers and radiologists to ensure their diagnostic performance is accurate and compliant with professional guidelines. Whenever possible, such audits should compare the sonographer's and radiologist's diagnostic opinion against patient outcomes. Comparing the sonographer's report with the report of the radiologist is not an effective audit strategy because radiologists make a comparable number of errors as sonographers [ 10 , 11 ]. Finally, we wish to acknowledge that one of the main limitations of this study is the modest number of HDC decisions involving sonographers. It is likely that many more complaints are brought by health consumers directly to individual practitioners and departments, but that these may be resolved without the need to notify the HDC and remain confidential and inaccessible to researchers. It is therefore likely the complaints in this series represent the severe side of the spectrum.

Health consumer complaints to the New Zealand Health and Disability Commissioner involving sonographers are rare, totalling 15 in the last 31 years and averaging 1.5 cases per year over the last decade. A large proportion of complaints involved an undetected finding, obstetric examination and private setting. The most common issue resulting in a complaint was a suboptimal examination that did not adhere to guidelines. In clinical settings where sonographers and radiologists work collaboratively and radiologists are reporting on the findings of a sonographer, both the sonographer and radiologist share collective responsibility for the outcome of the ultrasound examination.

The Health and Disability Commissioner (HDC) was established in 1994 as an independent watchdog to promote and protect the rights of all people in New Zealand who use health and disability services [ 1 ]. The Code of the Health and Disability Services Consumer's Rights (‘the Code’) sets out 10 rights granted to health consumers when receiving health services (Table  1 ). One of the key roles of the HDC is to investigate and resolve health consumer complaints. In 2024, the HDC received 3628 complaints, but not all complaints required a full investigation [ 2 ]. Code of Health and Disability Services Consumers' Rights. Following an investigation of a health provider (individual practitioner, group of practitioners, public or private health organisation, or any combination of providers), the HDC may come to one of several ‘decisions’ based on the available evidence and the opinion of appointed expert advisors. The health provider may be found in ‘breach’ of The Code. This is the most serious outcome, which typically results in notification to the practitioner's professional regulatory agency. Alternatively, the provider may receive an ‘adverse comment’. In this case, significant deficiencies are identified in the provider's service delivery; however, these do not reach the threshold of a breach. The provider may receive ‘other comment’, which can be in the form of a cautionary remark or recommendation. The provider may receive a ‘no breach’ decision if the practitioner is named in the complaints but is not at fault. The provider may also receive no decision, typically because the practitioner only played a peripheral role in the case. Finally, the provider may be listed as ‘not under investigation’. This may occur if the provider is not specifically named in the complaint even though they may have played a major role. Resolved and closed complaints are anonymised and published on the HDC website as a free resource [ 3 ]. Sonographers are highly skilled health providers who perform diagnostic ultrasound examinations. In New Zealand, the role of the sonographer also extends to the interpretation and communication of the results to other health professionals [ 4 ]. The professional title of ‘sonographer’ is protected in New Zealand. Sonographers must be registered with the New Zealand Medical Radiation Technologists' Board (MRTB) and hold an annual practising certificate (APC). Sonographers may be employed in a variety of clinical environments including: sonographer member of a medical imaging team, working in partnership with a radiologist [ 5 ] independently practicing ‘reporting sonographer’ [ 6 ] sonographer working directly with clinicians in diagnostic and/or educational roles [ 7 ] combination of clinical, academic and research roles. sonographer member of a medical imaging team, working in partnership with a radiologist [ 5 ] independently practicing ‘reporting sonographer’ [ 6 ] sonographer working directly with clinicians in diagnostic and/or educational roles [ 7 ] combination of clinical, academic and research roles. Sonographers perform highly complex psychomotor [ 8 ], cognitive, interpretive and reporting [ 9 ] tasks, all of which carry a risk of error. Although sonographer errors are rare [ 10 , 11 , 12 , 13 ], they can lead to adverse outcomes resulting in health consumer complaints. Understanding the root causes of complaints is critical, as sonographers work with a high degree of autonomy in a rapidly evolving health care environment, and often with minimal oversight. There is also an increasing trend for sonographers to work independently in ‘reporting sonographer’ roles as defined by current public employment contracts [ 6 ]. There are no published studies regarding complaints involving sonographers in New Zealand. A recent study on complaints involving New Zealand radiologists shows that despite the small number of complaints, ultrasound is the most commonly investigated modality [ 14 ]. As can be expected, many of the errors committed by radiologists originated with sonographers, with radiologists simply propagating the error [ 14 ]. A recent scoping review of litigation involving medical imaging professionals provides some valuable insights into common causes of litigation internationally, but the outcomes of the review are not directly applicable to the medicolegal environment of New Zealand [ 15 ]. The purpose of this study was, therefore, to review all HDC cases involving sonographers, summarise the key issues, analyse the results and provide robust discussion and advice on how such complaints can be avoided.

The authors declare no conflicts of interest.