Early experience with automated B-mode quality assurance tests.

Although quality assurance programmes have been recommended for many years, there is limited evidence of their efficacy. This study aimed to assess whether an automated image quality analysis method could demonstrate changes in scanner performance in a quality assurance programme. Test object images were analysed, measuring lateral resolution, low contrast penetration, slice thickness, anechoic target visibility and grey-scale target contrast and visibility. Known and suspected scanner faults were investigated and routine results were reviewed. At least one variable changed in response to each known or suspected scanner fault. Resolution and grey-scale target visibility changed due to image shadowing. Slice thickness, lateral resolution and grey-scale target contrast were affected where users reported deterioration in image quality. A single probe fell out of tolerance on routine testing, due to an unrecorded change to the default preset by the supplier's representative. Interpretation of individual results is not always intuitive, observed changes depending on the shape of the grey-scale transfer curve and on target and background echo levels. Our results have provided evidence for the efficacy of this method of performance testing. Further experience is required to evaluate this method for prospective detection of faults and further work is required to determine optimum scanner settings and test object properties to maximise fault detection and to reduce the dependence of results on confounding factors.

A case study in scanner optimisation.

Ultrasound scanner preset programmes are factory set or tailored to user requirements. Scanners may, therefore, have different settings for the same application, even on similar equipment in a single department. The aims of this study were: (1) to attempt to match the performance of two scanners, where one was preferred and (2) to assess differences between six scanners used for breast ultrasound within our organisation. The Nottingham Ultrasound Quality Assurance software was used to compare imaging performance. Images of a Gammex RMI 404GS test object were collected from six scanners, using default presets, factory presets and settings matched to a preferred scanner. Resolution, low contrast performance and high contrast performance were measured. The performance of two scanners was successfully matched, where one had been preferred. Default presets varied across the six scanners, three different presets being used. The most used preset differed in settings across the scanners, most notably in the use of different frequency modes. The factory preset was more consistent across the scanners, the main variation being in dynamic range (55-70 dB). Image comparisons showed significant differences, which were reduced or eliminated by adjustment of settings to match a reference scanner. It is possible to match scanner performance using the Nottingham Ultrasound Quality Assurance software as a verification tool. Ultrasound users should be aware that scanners may not behave in a similar fashion, even with apparently equivalent presets. It should be possible to harmonise presets by consensus amongst users.

Guideline for Technical Quality Assurance (TQA) of ultrasound devices (B-Mode)--version 1.0 (July 2012): EFSUMB Technical Quality Assurance Group--US-TQA/B.

The Technical Quality Assurance group was initiated by the EFSUMB Board in 2007 and met firstly in 2008 to discuss and evaluate methods and procedures published for performing technical quality assurance for diagnostic ultrasound devices. It is the aim of this group of experts to advise the EFSUMB Board of effective and efficacious methods for routine use and to make recommendations regarding the technical aspects of EFSUMB by-law 9, parts 11.6. & 11.7. The group's work focused on new developments and related European projects to establish a common guideline. There is a great need of a well established protocol and dedicated processing software for the performance testing of medical ultrasound equipment. The measurements should be user independent as much as physically possible. Only if these goals are achieved in an international (firstly European) context, the optimal quality of ultrasound imaging can be offered and maintained to the medical community. This guideline aims to offer and summarize suitable procedures and evaluation processes to lend support for an optimal Technical Quality Assurance (TQA) scheme. The content of this guideline was presented to the EFSUMB Board of Directors (delegates) and approved by the EFSUMB Executive Board (ExB) at the regular meeting during EUROSON 2012 in Madrid April 2012.

Efficacy of traps, lures, and repellents for Xylosandrus compactus (Coleoptera: Curculionidae) and other ambrosia beetles on Coffea arabica plantations and Acacia koa nurseries in Hawaii.

The black twig borer, Xylosandrus compactus (Eichhoff) (Coleoptera: Curculionidae: Scolytinae), is a pest of coffee and many endemic Hawaiian plants. Traps baited with chemical attractants commonly are used to capture ambrosia beetles for purposes of monitoring, studying population dynamics, predicting outbreaks, and mass trapping to reduce damage. The objectives of this research were to optimize trapping systems for X. compactus and other ambrosia beetles such as Xylosandrus crassiusculus (Motschulsky) and Xyleborinus saxesenii (Ratzeburg) by comparing efficacy of several attractants, repellents, and trap types. The ability of certain chemicals to act as beetle repellents and thus interfere with trap catch was tested for purposes of protecting host plants from attack. Potential attractants and application methods tested were as follows: ethyl alcohol pouch delivery system, ethyl alcohol vial delivery system, α-pinene in Eppendorf tubes, eugenol bubblecaps, ginger oil bubblecaps, manuka oil bubblecaps, phoebe oil bubblecaps, and an unbaited control. Potential repellents tested were limonene and verbenone. Ethyl alcohol vials were as attractive as ethyl alcohol sleeves, and were more effective than traps baited with eugenol and α-pinene. Japanese beetle traps were more effective for black twig borer trapping than Lindgren funnel traps, and were easier to deploy. Verbenone and limonene significantly reduced trap catch of Xylosandrus compactus and X. crassiusculus, suggesting that they may be effective for reducing attraction to host plants. These results show the importance of developing a combination of several monitoring techniques to enhance management procedures for the black twig borer.

'Rules of thumb' or reflective practice? Understanding senior physicians' decision-making about anti-thrombotic usage in atrial fibrillation.

BACKGROUND: The recently published Atrial Fibrillation (AF) Guidelines from the National Institute for Health and Clinical Excellence (NICE) highlight the importance of assessing stroke risk and using appropriate anti-thrombotic therapy. AIM: To improve understanding of physicians' behaviour and attitudes in respect to decision-making in AF and the use of anti-thrombotics. DESIGN: Semi-qualitative, questionnaire- and interview-based study. METHODS: Five clinical vignettes relating to treatment choices for AF and stroke prevention illustrating a range of risk and benefit were examined by 14 senior physicians (consultants or specialist registrars) in Cardiology, General Medicine and Geriatric Medicine, who then recommended anti-thrombotic treatment. A semi-structured interview explored their decision-making and prescribing in AF, with qualitative analysis of interview transcripts using grounded theory. RESULTS: There was marked variation in the choice of anti-thrombotic treatment. Respondents were more likely to prescribe warfarin to patients with a previous intracerebral haemorrhage than to a patient with a history of falls. A key theme on qualitative analysis revealed that decision-making in AF is often associated with uncertainty and concerns about knowledge of risk and benefit. DISCUSSION: In this study, doctors rarely agreed on the choice of anti-thrombotics in AF, and their perceptions of stroke and bleeding risk showed considerable variation. Uncertainty, doubt, concerns about knowledge and varied approach to the role of patients in decision-making are all significant themes in the considerable variability in anti-thrombotic prescribing.

Parafibromin mutations in hereditary hyperparathyroidism syndromes and parathyroid tumours.

OBJECTIVE: To investigate two patients with the hyperparathyroidism-jaw tumour (HPT-JT) syndrome and three patients with familial isolated hyperparathyroidism (FIHP), together with 31 parathyroid tumours (2 HPT-JT, 2 FIHP and 27 sporadic) for HRPT2 mutations. The HPT-JT syndrome and FIHP are autosomal dominant disorders that may be caused by abnormalities of the HRPT2 gene, located on chromosome 1q31.2. HRPT2 encodes a 531 amino acid protein, parafibromin, which interacts with human homologues of the yeast Paf1 complex. DESIGN: Leukocyte and tumor DNA was used with HRPT2-specific primers for polymerase chain reaction amplification of the 17 exons and their splice junctions, and the DNA sequences of the polymerase chain reaction products determined. RESULTS: Three heterozygous germline HRPT2 mutations, two in HPT-JT and one in FIHP patients, were identified. These consisted of one 1-bp duplication (745dup1bp), 1 nonsense (Arg234Stop) and 1 missense (Asp379Asn) mutation. One parathyroid tumour from an FIHP patient was demonstrated to harbour a germline deletion of 1 bp together with a somatic missense (Leu95Pro) mutation, consistent with a 'two-hit' model for hereditary cancer. The 27 sporadic benign parathyroid tumours did not harbour any HRPT2 somatic mutations. Six HRPT2 polymorphisms with allele frequencies ranging from 2% to 15% were detected. CONCLUSIONS: Our results have identified three novel HRPT2 mutations (two germline and one somatic). The Asp379Asn mutation is likely to disrupt interaction with the human homologue of the yeast Paf1 complex, and the demonstration of combined germline and somatic HRPT2 mutations in a parathyroid tumour provide further evidence for the tumour suppressor role of the HRPT2 gene.

Atrial fibrillation: will new drugs and patient choice improve anticoagulation outcomes?

The growing epidemic of atrial fibrillation presents major challenges to the healthcare community, both clinical and financial.

A systematic review of the ultrasound estimation of fetal weight.

OBJECTIVES: The range and use of ultrasound fetal measurements have gradually been extended. Measurements have been combined to estimate fetal weight by mathematically based non-linear regression analysis or physically based volumetric methods. Fetal weight estimation is inaccurate, with poor sensitivity for prediction of fetal compromise. Several authors have shown the unacceptable level of intra- and interobserver variability in fetal measurement and the impact of errors on growth assessment. The aims of this study were to review the available methods and possible sources of inaccuracy. METHODS: Four databases were searched for studies comparing ultrasound estimated fetal weight (EFW) with birth weight. Studies meeting the inclusion criteria evaluated 11 different methods. Errors were graphically summarized. RESULTS: No consistently superior method has emerged. Volumetric methods provide some theoretical advantages. Random errors are large and must be reduced if clinical errors are to be avoided. CONCLUSIONS: The accuracy of EFW is compromised by large intra- and interobserver variability. Efforts must be made to minimize this variability if EFW is to be clinically useful. This may be achieved through averaging of multiple measurements, improvements in image quality, uniform calibration of equipment, careful design and refinement of measurement methods, acknowledgment that there is a long learning curve, and regular audit of measurement quality. Further work to improve the universal validity and accuracy of fetal weight estimation formulae is also required.

Older people's understanding of cumulative risks when provided with annual stroke risk information.

Understanding how cumulative health risks increase over time constitutes an important part of decision making about treatment risks and benefits. In this study, wide ranging perceptions of cumulative risk led to significant overestimation and underestimation of risks over time. Time has shown to significantly impact on the personal interpretation of cumulative risk information by patients, with many subjects struggling to understand the concept of cumulative risks. This suggests that a careful explanation of the effect of cumulative risk over time to patients should contribute to more effective decision making.

Radioisotope for occult lesion localisation (ROLL) of the breast does not require extra radiation protection procedures.

AIM OF STUDY: Dosimetry data from patients and hospital personnel involved in the use of radioisotope for occult lesion localisation (ROLL) of the breast were collected to determine the need for extra radiation protection procedures. METHODS: Sixty-three patients have been enrolled to date into a randomised trial evaluating ROLL. Two megabecquerels of (99m)Tc- MAA in a syringe was mixed with X-ray contrast medium; this was injected directly into the lesion under image guidance. A gamma-detecting probe (Neo-Probe) was used to locate the area of radioactivity. Radiation doses to all staff groups were estimated using time and motion studies and dose rate measurements at a range of distances during each stage of ROLL. RESULTS: The finger dose [FD](+/-95% CI) was considered to be the critical variable for surgeons and radiologists. Surgeon FD=9.3+/-3.3 microSv, Radiologist FD=0.5+/-0.13 microSv. Whole body doses [WBD](+/-95% CI) were estimated for other staff groups. Nurse WBD=0.4+/-0.4 microSv, porter WBD: nil, contamination and waste: nil. CONCLUSIONS: In the case of a surgeon performing 100 procedures per annum, a FD dose of approximately 1 mSv is received, well within the annual dose limit of 150 mSv. Annual WBD to assisting staff may reach 0.04 mSv, compared to an annual limit of 6 mSv. These low doses and the lack of contamination of radioactive waste indicate that no additional radiation protection measures are required.

Clinical agreement between automated and calculated ultrasound measurements of bladder volume.

Non-invasive urine volume measurement is an important tool in the management of dysfunctional and neuropathic bladders in children. Ultrasound imaging devices have been used for many years for this purpose. An automated scanner (Bladderscan) is now available and has been recommended by a number of authors, but there is conflicting evidence in the literature regarding the accuracy and appropriate clinical application of the device. We aimed to assess the level of clinical agreement between the two methods. 36 urine volume measurements were made on 11 children using both instruments. Although there was a good correlation between the methods (r=0.97), the clinical agreement was poor (limits of agreement +/-77 ml). 13 voided volumes were directly measured and compared with the difference between pre- and post-void ultrasound measurements. The systematic errors were small but the mean absolute errors were 54 ml and 23 ml, respectively, for the automated and ultrasound imaging methods. If used correctly, ultrasound imaging provides more accurate results and can compete with the cost, convenience and ease of use of the automated method. Low cost, highly portable ultrasound imaging devices are now available and should be used in preference to the Bladderscan.

How informed is consent? Understanding of pictorial and verbal probability information by medical inpatients.

Understanding probability information about treatment risks and benefits is a vital component of patients' decision making capacity. This study demonstrates extensive misunderstanding of verbal descriptions of probability by medical inpatients of all ages, questioning the extent of their capacity for giving informed consent. Pictorial descriptions of probability were well understood, suggesting their adoption into clinical practice.

The importance of quality management in fetal measurement.

OBJECTIVES: The aims of this study were to evaluate factors contributing to inaccuracy in fetal measurements and to assess the clinical importance of measurement quality. METHODS: One hundred images of biparietal diameter (BPD), head circumference (HC) and abdominal circumference (AC) measurements were collected from six centers (1800 measurements); the proportion meeting quality criteria was assessed. Four hundred images of AC were collected from one center, each image measured by ellipse fitting and tracing methods; clinical agreement between the methods was assessed. Fetal weight estimation (EFW) errors were compared between quality controlled and non-quality controlled studies. Images of three ACs on each of 400 fetuses were collected; where one measurement failed to meet quality criteria, it was compared with an optimal measurement on the same fetus. RESULTS: Eighty-nine percent, 87% and 60% of BPD, HC and AC, respectively, met all quality criteria. Limits of agreement between ellipse and traced AC were -4.7 mm to 12.5 mm; 22% of sections were non-elliptical. EFW errors were significantly different but were confounded by differences in time to delivery. Limits of agreement between optimal and suboptimal AC measurements were -15.1 mm to 7.7 mm. CONCLUSIONS: AC quality criteria are less easily recognized and obtained than those for head measurements; training, adherence to protocols and audit are important. Differences between ellipse and traced AC may not justify the use of separate charts; the number of non-elliptical sections suggests that ellipse fitting is not appropriate. Comparison between EFW errors is not a suitable tool for audit. Failure to meet quality criteria results in clinically significant errors.

Risk communication and older people-understanding of probability and risk information by medical inpatients aged 75 years and older.

OBJECTIVE: To determine older people's understanding of probability and risk information, and the impact of pictorial representation of risk. DESIGN: A researcher-administered questionnaire. SUBJECTS: 50 inpatients aged > or =75 years on elderly medicine wards at Huddersfield Royal Infirmary, Huddersfield, UK. RESULTS: Older people understand percentage probability better than fractional probability, and a wide range of incorrect responses indicated significant over- and underestimation of probabilities. Visual data about percentages were well received and understood, and were perceived as a good idea by participants. CONCLUSIONS: We have demonstrated a wide variation in understanding of risk and probability information by older people, with over- and underestimations of probability, along with confusion between fractional and percentage probability. Pictorial representation of probability was well understood. It could be developed as a simple, yet powerful communication tool to be used in daily clinical practice to help older people understand information on risks and benefits when making decisions about treatment choices.

Importance of risk communication and decision making in cardiovascular conditions in older patients: a discussion paper.

Atrial fibrillation and aortic stenosis commonly present doctors and patients with difficult decisions about the risks and benefits of treatment options and are both often inappropriately undertreated. Patients may be confused by risk information and doctors may be aware of patients' limitations and use this to manipulate choices to the ones desired by the doctors. This paper examines the importance of risk communication and discusses difficulties that can arise in decision making in these two common cardiovascular conditions.

A review of two alternative ultrasound quality assurance programmes.

OBJECTIVE: This study reviewed the results of B-mode Quality Assurance (QA) performance tests on 17 real-time ultrasound scanners, performed over a period of 3 years, in order to assess their value. Following this review we revised and simplified our testing schedules to include two tests for noise and sensitivity. The value of the new schedules was assessed. METHODS: Initially, testing schedules were similar to those recommended by two professional bodies. Results were reviewed to determine whether the tests predicted or confirmed faults. We then introduced a simplified testing programme using alternative measurements, attempting to demonstrate or predict noise related faults that affect the image, but were not demonstrated by current tests. These new tests have been performed on 24 ultrasound machines for up to 18 months. RESULTS: A review of results has shown that measurements occasionally fall outside tolerance due to chance, and that faults that significantly affect the image, e.g. probe faults and noise, are reported by the users without predictive or concomitant changes in test results using our original schedules. Faults occur that do not immediately affect image quality and are not reported by the users. Inappropriate settings, e.g. monitors, are frequently reset at QA, particularly where there are potentially untrained users. The additional tests showed consistent changes in noise (four) or sensitivity (one) on five machines. CONCLUSION: Our earlier tests were inadequate in demonstrating deterioration in the clinical performance of ultrasound imaging equipment. Introduction of a revised testing schedule has resulted in changes in equipment performance being detected and rectified.