Subjective Versus Quantitative Methods of Assessing Breast Density.

In order to find a consistent, simple and time-efficient method of assessing mammographic breast density (MBD), different methods of assessing density comparing subjective, quantitative, semi-subjective and semi-quantitative methods were investigated. Subjective MBD of anonymized mammographic cases (n = 250) from a national breast-screening programme was rated by 49 radiologists from two countries (UK and USA) who were voluntarily recruited. Quantitatively, three measurement methods, namely VOLPARA, Hand Delineation (HD) and ImageJ (IJ) were used to calculate breast density using the same set of cases, however, for VOLPARA only mammographic cases (n = 122) with full raw digital data were included. The agreement level between methods was analysed using weighted kappa test. Agreement between UK and USA radiologists and VOLPARA varied from moderate (κw = 0.589) to substantial (κw = 0.639), respectively. The levels of agreement between USA, UK radiologists, VOLPARA with IJ were substantial (κw = 0.752, 0.768, 0.603), and with HD the levels of agreement varied from moderate to substantial (κw = 0.632, 0.680, 0.597), respectively. This study found that there is variability between subjective and objective MBD assessment methods, internationally. These results will add to the evidence base, emphasising the need for consistent, simple and time-efficient MBD assessment methods. Additionally, the quickest method to assess density is the subjective assessment, followed by VOLPARA, which is compatible with a busy clinical setting. Moreover, the use of a more limited two-scale system improves agreement levels and could help minimise any potential country bias.

Variability of Breast Density Classification Between US and UK Radiologists.

PURPOSE: To assess whether subjective breast density categorization remains the most useful way to categorize mammographic breast density and whether variations exist across geographic regions with differing national legislation. METHODS: Breast radiologists from two countries (UK, USA) were voluntarily recruited to review sets of anonymized mammographic images (n = 180) and additional repeated images (n = 70), totaling 250 images, to subjectively rate breast density according to the Breast Imaging Reporting and Data system (BI-RADS) categorization. Images were reviewed using standardized viewing conditions and Ziltron software. Inter-rater reliability was analyzed using the Kappa test. RESULTS: The US radiologists (n = 25) judged fewer images as being "mostly fatty" than UK radiologists (n = 24), leading a greater number of images classified in the higher BI-RADS categories, particularly in BI-RADS 3. Overall agreement for all data sets was k = 0.654 indicating substantial agreement between the two cohorts. When the data were split into BI-RADS categories, the level of agreement varied from fair to substantial. CONCLUSION: Variations in how radiologists from the USA and UK classify breast density was established, especially when the data were divided into breast density categories. This variation supports the need for a reliable breast density assessment method to enhance the individualized supplemental screening pathways for dense breasts. The use of two-scale categorization method demonstrated improved agreement. ADVANCES IN KNOWLEDGE: Larger sample of radiologists from different breast density jurisdictions confirms international subjective variability in density categorization and improved agreement with the two-scale (low, high) categorization. With this variability, a standardized and automated breast density assessment shows to be timely.

AN INVESTIGATION INTO CT RADIATION DOSE VARIATIONS FOR HEAD EXAMINATIONS ON MATCHED EQUIPMENT.

This study investigated radiation dose and image quality differences for computed tomography (CT) head examinations across centres with matched CT equipment. Radiation dose records and imaging protocols currently employed across three European university teaching hospitals were collated, compared and coded as Centres A, B and C from specification matched CT equipment models. Patient scans (n = 40) obtained from Centres A and C were evaluated for image quality, based on the visualisation of Commission of European Community (CEC) image quality criteria using visual grading characteristic (VGC) analysis, where American Board of Radiology examiners (n = 11) stated their confidence in identifying anatomical criteria. Mean doses in terms of CT dose index (CTDIvol-mGy) and dose length product (DLP-mGy cm) were as follows: Centre A-33.12 mGy and 461.45 mGy cm; Centre B -101 mGy (base)/32 mGy (cerebrum) and 762 mGy cm and Centre C-71.98 mGy and 1047.26 mGy cm, showing a significant difference (p ≤ 0.05) in DLP across centres. VGC analysis indicated better visualisation of CEC criteria on Centre C images (VGCAUC 0.225). All three imaging protocols are routinely used clinically, and image quality is acceptable in each centre. Clinical centres with identical model CT scanners have variously customised their protocols achieving a range of dose savings and still resulting in clinically acceptable image quality.

Is the iPad suitable for image display at American Board of Radiology examinations?

OBJECTIVE: The study aimed to determine the acceptability of the iPad 3 as a display option for American Board of Radiology (ABR) examinations. SUBJECTS AND METHODS: A set of 20 cases for each of nine specialties examined by the ABR was prepared. Each comprised between one and seven images and case information and had been used in previous ABR Initial Certification examinations. Examining radiologists (n = 119) at the ABR oral Initial Certification examinations reviewed sets from one or more specialties on both a 2 MP LED monitor and on the iPad 3 and rated the visibility of the salient image features for each case. The Wilcoxon signed rank test was performed to compare ratings. In addition, a thematic analysis of participants' opinions was undertaken. RESULTS: When all specialties were pooled, the iPad 3 ratings were significantly higher than the monitor ratings (p = 0.0217). The breast, gastrointestinal, genitourinary, and nuclear medicine specialties also returned significantly higher ratings for the visibility of relevant image features for the iPad 3. Monitor ratings were significantly higher for the vascular and interventional specialty, although no images were rated unacceptably poor on the iPad in this specialty. CONCLUSION: The relevant image features were rated more visible on the iPad 3 than on the monitors overall. The iPad 3 was well accepted by a large majority of examiners and can be considered adequate for image display for examination in most or all specialties.

A multiobserver study of the effects of including point-of-care patient photographs with portable radiography: a means to detect wrong-patient errors.

RATIONALE AND OBJECTIVES: To evaluate whether the presence of facial photographs obtained at the point-of-care of portable radiography leads to increased detection of wrong-patient errors. MATERIALS AND METHODS: In this institutional review board-approved study, 166 radiograph-photograph combinations were obtained from 30 patients. Consecutive radiographs from the same patients resulted in 83 unique pairs (ie, a new radiograph and prior, comparison radiograph) for interpretation. To simulate wrong-patient errors, mismatched pairs were generated by pairing radiographs from different patients chosen randomly from the sample. Ninety radiologists each interpreted a unique randomly chosen set of 10 radiographic pairs, containing up to 10% mismatches (ie, error pairs). Radiologists were randomly assigned to interpret radiographs with or without photographs. The number of mismatches was identified, and interpretation times were recorded. RESULTS: Ninety radiologists with 21 ± 10 (mean ± standard deviation) years of experience were recruited to participate in this observer study. With the introduction of photographs, the proportion of errors detected increased from 31% (9 of 29) to 77% (23 of 30; P = .006). The odds ratio for detection of error with photographs to detection without photographs was 7.3 (95% confidence interval: 2.29-23.18). Observer qualifications, training, or practice in cardiothoracic radiology did not influence sensitivity for error detection. There is no significant difference in interpretation time for studies without photographs and those with photographs (60 ± 22 vs. 61 ± 25 seconds; P = .77). CONCLUSIONS: In this observer study, facial photographs obtained simultaneously with portable chest radiographs increased the identification of any wrong-patient errors, without substantial increase in interpretation time. This technique offers a potential means to increase patient safety through correct patient identification.

Number of mammography cases read per year is a strong predictor of sensitivity.

Early detection of breast cancers affects the 5-year recurrence rates and treatment options for diagnosed patients, and consequently, many countries have instituted nationwide screening programs. This study compared the performance of expert radiologists from Australia and the United States in detection of breast cancer. Forty-one radiologists, 21 from Australia and 20 from the United States, reviewed 30 mammographic cases containing two-view mammograms. Twenty cases had abnormal findings and 10 cases had normal findings. Radiologists were asked to locate malignancies and assign a level of confidence. A jackknife free-response receiver operating characteristic, figure of merit (JAFROC, FOM), inferred receiver operating characteristic, area under curve (ROC, AUC), specificity, sensitivity, and location sensitivity were calculated using Ziltron software and JAFROC v4.1. A Mann-Whitney U test was used to compare the performance of Australian and U.S. radiologists. The results showed that when experience and the number of mammograms read per year were taken into account, the Australian radiologists sampled showed significantly higher sensitivity and location sensitivity ([Formula: see text]). JAFROC (FOM) and inferred ROC (AUC) analysis showed no difference between the overall performance of the two countries. ROC (AUC) and location sensitivity were higher for the Australian radiologists who read the most cases per year.

Caudocranial scan direction and patient-specific injection protocols optimize ECG-gated and non-gated thoracic CTA.

OBJECTIVES: Caudocranial scan direction and contrast injection timing based on measured patient vessel dynamics can significantly improve artery opacification and reduce contrast dose in the assessment of acute aortic syndrome using gated and non-gated thoracic CTA. This study aimed to investigate enhancement of the thoracic aorta using caudocranial scan direction and a patient-specific contrast regimen. METHODS: Electrocardiogram-gated (n = 120) and non-gated (n = 200) thoracic computed tomography angiography was performed on patients with nontraumatic acute aortic syndrome. Patients were assigned to one of 2 acquisition/contrast regimens, namely, regimen A, craniocaudal scan direction with 120 mL contrast, and regimen B, caudocranial scan direction using a patient-specific contrast formula. Opacity of 9 arterial and venous segments was measured, arteriovenous contrast ratio calculated, and values compared using Mann-Whitney U statistics. Receiver operating characteristic analyses and visual grading characteristic assessed diagnostic efficacy and clinical image quality. Interobserver variations were investigated using κ methods. RESULTS: Regimen B when compared to A, for both scanning/contrast techniques, demonstrated higher opacification in the aorta (P < 0.01) and lower opacification in the venous system (P < 0.0001). For protocol B, arteriovenous contrast ratio was significantly increased (P < 0.0001) and mean contrast volume reduced (P < 0.05) during gated [94 (10 mL)] and non-gated [78 (5 mL)] thoracic computed tomography angiography compared to A. Receiver operating characteristic analysis Az scores and interobserver agreement were significantly higher with regimen B than A (P < 0.05). CONCLUSIONS: Caudocranial scan direction and injection timing based on patient-specific vessel dynamics can optimize artery opacification and diagnostic efficacy while reducing contrast volumes.

The effect of JPEG2000 compression on detection of skull fractures.

RATIONAL AND OBJECTIVES: To investigate the effect of the Joint Photographic Experts Group (JPEG2000) 30:1 and 60:1 lossy compression on the detection of cranial vault fractures when compared to JPEG2000 lossless compression. MATERIALS AND METHODS: Fifty cranial computed tomography (CT) images were processed with three different level of JPEG2000 compression (lossless, 30:1 lossy, and 60:1 lossy) creating three sets of images. These were presented to five musculoskeletal specialists and five neuroradiologists. Each reader read at two of the three compression levels. Twenty-two cases contained a single fracture; the remaining 28 cases contained no fractures. Observers were asked to identify the presence or absence of a fracture, to locate its site, and rate their degree of confidence. Receiver operating characteristic (ROC), jackknife free-response receiver operating characteristic (JAFROC) and the Dorfman-Berbaum-Metz multiple reader multiple case (DBM-MRMC) analyses were used to explore differences between the lossless and lossy compressed images. RESULTS: JPEG2000 lossless and 30:1 lossy compression demonstrated no significant difference in their performance with JAFROC and DBM-MRMC analysis (P < .416); however, JPEG2000 30:1 lossy compression demonstrated significantly better performance than 60:1 lossy compression (P < .016). A significant increase in misplaced confidence ratings was also seen with 60:1 (P < .037) over 30:1 lossy and lossless compression. CONCLUSION: JPEG2000 60:1 compression degrades the detection of skull fractures significantly while increasing the confidence with which readers rate fractures compared with 30:1 lossy and lossless compression. JPEG2000 30:1 lossy compression does not significantly change performance when compared to JPEG2000 lossless for the detection of skull fractures on CT.

A reduced contrast volume acquisition regimen based on cardiovascular dynamics improves visualisation of head and neck vasculature with carotid MDCT angiography.

PURPOSE: To investigate enhancement of head and neck arteries during carotid computed tomography angiography using a reduced volume contrast regimen and craniocaudal scan acquisition. MATERIALS AND METHODS: Two hundred and two patients underwent carotid angiography using a 64 channel computed tomography scanner. Patients were allocated to one of two acquisition/contrast regimens: regimen A, the department's standard protocol, consisting of a caudocranial scan direction with 100mL of contrast intravenously; regimen B, involving a craniocaudal scan direction and approximately 50 mL of contrast using a timing dictated by patient hemodynamics. Attenuation profiles of cranial arteries and veins in 6 anatomical segments were assessed and arteriovenous contrast ratios (AVCR) calculated. Receiver operating characteristic (ROC) analysis was performed using DBM methodology. RESULTS: Arterial attenuation was up to 54% (p<0.01) higher following regimen B compared with A. Attenuation in the veins were significantly lower in regimen B than in regimen A with a maximum reduction of up to 93% (p<0.0001). With regimen B, there were significant (p<0.0001) improvements in AVCR at a variety of anatomical sites. The ROC analysis demonstrated a significantly higher Az score for the novel regimen compared with regimen A (p<0.002) with inter-neuroradiologist agreement increasing from poor to moderate. CONCLUSION: Significant improvements in visualisation of head and neck arterial vasculature can be achieved with a CT acquisition regimen using low contrast volume and injection timing based on patient specific contrast formula and craniocaudal scan direction.

Flexible image evaluation: iPad versus secondary-class monitors for review of MR spinal emergency cases, a comparative study.

RATIONALE AND OBJECTIVES: Studies have highlighted the potential of handheld viewing devices for rapid diagnosis and increased smartphone usage among physicians and radiologists is known as is the clinical applicability of hand-held devices for computed tomography (CT) spinal injury cases. Magnetic resonance (MR), however, is the accepted gold standard for spinal imaging, providing visualization of both ligament and spinal cord pathology. This study investigated the diagnostic accuracy of the iPad, the most probable alternative display device outside the radiology environment and financially viable alternative, when reviewing emergency spinal MR images, in comparison with secondary-class LCD devices in the case of the interpretation of CT and MR imaging examinations. MATERIALS AND METHODS: In total 31 MR cases including both positives (n = 13) containing one of four possible presentations: spinal cord compression, cauda equine syndrome, spinal cord hemorrhage, or spinal cord edema and controls (n = 18) were reviewed. Ziltron iPad software facilitated the display of cases and the receiver operating characteristic (ROC) analysis. Thirteen American Board of Radiology board-certified radiologists reviewed all cases on both displays. Standardized viewing conditions were maintained. RESULTS: Dorfman-Berbaum-Metz multireader-multicase (DBM MRMC) analysis was performed including random readers/random cases, fixed readers/random cases and random readers/fixed cases. No differences of statistical significance (P ≤ .05) could be found in terms of area under the curve, sensitivity and specificity between the iPad and secondary-class display. CONCLUSION: The iPad performed with equal diagnostic accuracy when compared with the secondary-class LCD device after DBM MRMC analysis, demonstrating the iPad as an option to aid initial review of MR spinal emergency cases.

The "memory effect" for repeated radiologic observations.

OBJECTIVE: It is assumed that memory has a role to play in repeated radiologic observation studies. The main objective of this study was to examine this assumption and evaluate the effect that memory may have on receiver operating characteristic (ROC) methods. MATERIALS AND METHODS: A two-center observer study was performed with a total of 24 experienced radiologists. Over two viewings, chest radiographs showing the tip of a central line in either the superior vena cava or the azygos vein were presented. Half of the images were changed between the two viewings. The participants' attention was directed on the first reading to the position of the central line. At the second reading, the participants were asked to assign a confidence score on a 6-point scale about whether each image had been included in the first reading. RESULTS: For the images that were scored as "definitely included" in the first viewing, readers at our two centers recalled only an average of 2.5 and 4.9 of the 20 repeated images, which is close to a random allocation of images to each score. As the confidence levels diminished for positive identification of repeated images, the numbers of correct answers increased. For images scored as not having been previously included, the numbers of correct answers remained low suggesting that identification of nonrepeated images is poor. Images with a greater number of incidental abnormalities and with more striking abnormalities were recognized more accurately than those with fewer and less striking abnormalities. CONCLUSION: This study shows a "memory effect" when the same images are presented at a second viewing within a small interval period. This effect appears to occur mainly at low confidence levels. These results suggest that including images with obvious incidental abnormalities in reader performance studies should be avoided.

Auxin-induced leaf blade expansion in Arabidopsis requires both wounding and detachment.

Elevation of leaf auxin (indole-3-acetic acid; IAA) levels in intact plants has been consistently found to inhibit leaf expansion whereas excised leaf strips grow faster when treated with IAA. Here we test two hypothetical explanations for this difference in growth sensitivity to IAA by expanding leaf tissues in vivo versus in vitro. We asked if, in Arabidopsis, IAA-induced growth of excised leaf strips results from the wounding required to excise tissue and/or results from detachment from the plant and thus loss of some shoot or root derived growth controlling factors. We tested the effect of a range of exogenous IAA concentrations on the growth of intact attached, wounded attached, detached intact, detached wounded as well as excised leaf strips. After 24 h, the growth of intact attached, wounded attached, and detached intact leaves was inhibited by IAA concentrations as little as 1 µM in some experiments. Growth of detached wounded leaves and leaf strips was induced by IAA concentrations as low as 10 µM. Stress, in the form of high light, increased the growth response to IAA by leaf strips and reduced growth inhibition response by intact detached leaves. Endogenous free IAA content of intact attached leaves and excised leaf strips was found not to change over the course of 24 h. Together these results indicate growth induction of Arabidopsis leaf blade tissue by IAA requires both substantial wounding as well as detachment from the plant and suggests in vivo that IAA induces parallel pathways leading to growth inhibition.

The effect of abnormality-prevalence expectation on expert observer performance and visual search.

PURPOSE: To measure the effect of abnormality-prevalence expectation on experienced radiologists' performance during pulmonary nodular lesion detection on a chest radiograph. MATERIALS AND METHODS: A multiobserver receiver operating characteristic (ROC) and eye-position analysis study was performed to assess the effect of prevalence expectation on observer performance. Twenty-two experienced radiologists were divided into three groups and each was asked to interpret 30 (15 abnormal) identical posteroanterior chest images twice and decide if pulmonary lesions were present. Before each viewing, the radiologists were told that the images contained a specific number of abnormal images: group 1: 9 and 15; group 2: 15 and 22; and group 3: 15 and not told. RESULTS: ROC analysis demonstrated that no significant effect could be measured as a function of prevalence expectation (P > .05). However, eye-position analysis showed significant increases in eye movements at higher prevalence expectation rates in terms of the number of fixations per image (group 1: P = .0001; group 2: P = .0001; group 3: P = .001) and the total scrutiny time of each image (group 1: P = .0001; group 2: P = .0283; group 3: P = .028). CONCLUSION: Overall, findings of this study showed no evidence that the accuracy of expert radiologists is altered due to changing prevalence expectation rates. However, the time spent interpreting each image and the number of fixations increased at higher prevalence rates. Maintenance of diagnostic efficacy has been shown even when circumstances challenge normal observer behavior.

Variations in performance of LCDs are still evident after DICOM gray-scale standard display calibration.

OBJECTIVE: Quality assurance in medical imaging is directly beneficial to image quality. Diagnostic images are frequently displayed on secondary-class displays that have minimal or no regular quality assurance programs, and treatment decisions are being made from these display types. The purpose of this study is to identify the impact of calibration on physical and psychophysical performance of liquid crystal displays (LCDs) and the extent of potential variance across various types of LCDs. MATERIALS AND METHODS: Three display types were evaluated from Hewlett Packard, Viewsonic, and NEC, which totalled 36 LCDs. These displays were calibrated to the DICOM gray scale standard display function using a VeriLum photometer and associated software under the same ambient room conditions. The American Association of Physicists in Medicine Task Group 18 test patterns were used to measure minimum and maximum luminance, contrast ratios, luminance response, veiling glare (physical and psychophysical), psychophysical noise, spatial resolution, and display uniformity. RESULTS: Improvements after calibration were noted in all display types for luminance response and psychophysical evaluations of veiling glare. Minimum luminance, contrast ratios, and display uniformity improvements were noted in two separate display types. The only significant reduction in performance was noted for physical evaluations of veiling glare. CONCLUSION: The data presented show that calibration has a significant impact on the brightness and contrast of displays, and other display parameters are influenced by this. The amount of variation in performance that was still evident after calibration is of concern.

Diagnostic efficacy of handheld devices for emergency radiologic consultation.

OBJECTIVE: Orthopedic injury and intracranial hemorrhage are commonly encountered in emergency radiology, and accurate and timely diagnosis is important. The purpose of this study was to determine whether the diagnostic accuracy of handheld computing devices is comparable to that of monitors that might be used in emergency teleconsultation. SUBJECTS AND METHODS: Two handheld devices, a Dell Axim personal digital assistant (PDA) and an Apple iPod Touch device, were studied. The diagnostic efficacy of each device was tested against that of secondary-class monitors (primary class being clinical workstation display) for each of two image types-posteroanterior wrist radiographs and slices from CT of the brain-yielding four separate observer performance studies. Participants read a bank of 30 wrist or brain images searching for a specific abnormality (distal radial fracture, fresh intracranial bleed) and rated their confidence in their decisions. A total of 168 readings by examining radiologists of the American Board of Radiology were gathered, and the results were subjected to receiver operating characteristics analysis. RESULTS: In the PDA brain CT study, the scores of PDA readings were significantly higher than those of monitor readings for all observers (p < or = 0.01) and for radiologists who were not neuroradiology specialists (p < or = 0.05). No statistically significant differences between handheld device and monitor findings were found for the PDA wrist images or in the iPod Touch device studies, although some comparisons approached significance. CONCLUSION: Handheld devices show promise in the field of emergency teleconsultation for detection of basic orthopedic injuries and intracranial hemorrhage. Further investigation is warranted.

Evaluation of off-the-shelf displays for use in the American Board of Radiology maintenance of certification examination.

PURPOSE: To prospectively compare high-, mid-, and low-resolution off-the-shelf displays currently employed by commercial testing centers, in terms of visibility of lesion features needed to render a diagnostic decision when possible diagnoses are provided in a multiple-choice format during a maintenance of certification (MOC) examination. MATERIALS AND METHODS: The Psychometrics Division of the American Board of Radiology (ABR) approved the studies (human subjects and HIPAA compliant). One study compared 1280 x 1024 displays with 1024 x 768 displays; the second, 1600 x 1200 with 1280 x 1024 displays. Images from nine subspecialties were used. In each study, observers viewed images twice-once on each display. Diagnoses were provided, and observers rated visibility of diagnostic features. RESULTS: Of 7977 data pairs analyzed in study 1, the 1024 and 1280 displays received the same ratings for 5726 data pairs (72% of the time), with the 1024 display receiving a higher rating for 679 data pairs (9% of the time) and the 1280 receiving a higher rating for 1572 data pairs (19% of the time) (P < .0001). When rating differences existed, all subspecialties except nuclear medicine had significantly more high-visibility ratings with the 1280 display. Of 1090 data pairs analyzed in study 2, the 1280 and 1600 displays received the same ratings for 689 data pairs (63% of the time), with the 1280 receiving a higher rating for 162 data pairs (15% of the time) and the 1600 receiving a higher rating for 239 data pairs (22% of the time) (P = .0001). When rating differences existed, only cardiopulmonary and musculoskeletal images had significantly more high-visibility ratings with the 1600 display. CONCLUSION: For the ABR MOC examinations, 1280 x 1024 displays should be used, compared to 1024 x 768 displays; 1600 x 1200 displays may be necessary for some images. Good-quality images must be used on the examinations, so digital rather than digitized film images should be used to ensure high-quality images.

Ambient lighting: effect of illumination on soft-copy viewing of radiographs of the wrist.

OBJECTIVE: The aim of the work was to establish optimum ambient light conditions for viewing radiologic images of the wrist on liquid crystal display monitors. MATERIALS AND METHODS: Five ambient light levels were investigated: 480, 100, 40, 25, and 7 lux. Seventy-nine experienced radiologists were asked to examine 30 posteroanterior wrist images and decide whether a fracture was present. All images were displayed on liquid crystal display monitors. Receiver operating characteristic analysis was performed, and the numbers of false-positive and false-negative findings were recorded. RESULTS: For all the radiologists, greater area under the receiver operating characteristic curve and lower numbers of false-positive and false-negative findings were recorded at 40 and 25 lux compared with 480 and 100 lux. At 7 lux, the results were generally similar to those at 480 and 100 lux. The experience and knowledge of radiologists specializing in imaging of musculoskeletal trauma appeared to compensate in part for inappropriate lighting levels. CONCLUSION: Typical office lighting and current recommendations on ambient lighting can reduce diagnostic efficacy compared with lower levels of ambient lighting. If, however, no light other than that of the monitor is used, results are similar to those with excessive levels of lighting. Careful control of ambient lighting is therefore required to ensure that diagnostic accuracy is maximized, particularly for clinicians not expert in interpreting posteroanterior wrist images.