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Diagnostic efficacy in medical imaging is ultimately a reflection of radiologist performance. This can be influenced by numerous factors, some of which are patient related, such as the physical size and density of the breast, and machine related, where some lesions are difficult to visualise on traditional imaging techniques. Other factors are human reader errors that occur during the diagnostic process, which relate to reader experience and their perceptual and cognitive oversights. Given the large-scale nature of breast cancer screening, even small increases in diagnostic performance equate to large numbers of women saved. It is important to identify the causes of diagnostic errors and how detection efficacy can be improved. This narrative review will therefore explore the various factors that influence mammographic performance and the potential solutions used in an attempt to ameliorate the errors made.

The purpose of this study was to introduce a continuous quality improvement (CQI) program for radiation dose optimisation during uterine artery embolisation (UAE) and assess its impact on dose reduction and image quality. The CQI program investigated the effects of optimising radiation dose parameters on the kerma-area product (KAP) and image quality when comparing a ‘CQI intervention’ group (n = 50) and ‘Control’ group (n = 50). Visual grading characteristics (VGC) analysis was used to assess image quality, using the ‘Control’ group as a reference. A significant reduction in KAP by 17% (P = 0.041, d = 0.2) and reference air kerma (Ka, r) by 20% (P = 0.027, d = 0.2) was shown between the two groups. The VGC analysis resulted in an area under the VGC curve (AUCVGC) of 0.54, indicating no significant difference in image quality between the two groups (P = 0.670). The implementation of the CQI program and optimisation of radiation dose parameters improved the UAE radiation dose practices at our centre. The dose reduction demonstrated no detrimental effects on image quality.

Diverticular disease is one of the most common causes of outpatient visits and hospitalisations across Australia, North America and Europe. According to the Gastroenterological Society of Australia (GESA, 2010), approximately 33% of Australians over 45 years of age and 66% over 85 years of age have some form of colonic diverticulosis. Patients with colonic diverticulosis are known to develop subsequent complications such as acute colonic diverticulitis (ACD), and when more than one attack of diverticulitis occurs, there is a 70‐90% chance that the individual will experience ongoing problems and recurring infections throughout their lifetime. Medical imaging is fundamental in the diagnosis, treatment and ongoing management of ACD and its complications, with Computed Tomography (CT) identified as the prevailing gold standard in the last few decades. Cross‐database searching highlighted a large gap in the literature regarding the effectiveness of Magnetic Resonance Imaging (MRI) as a non‐ionising radiation alternative imaging tool for ACD imaging after the mid‐2000s, despite ongoing technological advancements in this modality. This narrative review identified 13 key publications (11 primary prospective cohort studies, 1 systematic review and 1 meta‐analysis) that evaluate MRI for ACD imaging, of which five were published within the last decade. Several existing MRI protocols are deemed suitable for ACD imaging, and it is recommended they be re‐evaluated in larger cohorts. Future studies should consider the rapidly growing technological improvements of MRI, its cost efficiency and its applicability in modern day healthcare settings when addressing ACD management. This is especially important considering the gradual rise in radiation dose among the Australian population attributable to increased CT referrals, alongside increased reporting of ACD cases in younger individuals., Diverticular disease is one of the most common causes of outpatient visits and hospitalisations. Cross‐database searching has highlighted a large gap in the literature: an absence of publications providing efficacy data on Magnetic Resonance Imaging (MRI) as a non‐ionising radiation alternative for ACD. This narrative review aims to explore available published data and provide an up‐to‐date evaluation of MRI as a tool for the diagnosis and ongoing management of ACD.

Introduction Early detection of malignant pulmonary nodules through screening has been shown to reduce lung cancer‐related mortality by 20%. However, perceptual and cognitive factors that affect nodule detection are poorly understood. This review examines the cognitive and visual processes of various observers, with a particular focus on radiologists, during lung nodule detection. Methods Four databases (Medline, Embase, Scopus and PubMed) were searched to extract studies on eye‐tracking in pulmonary nodule detection. Studies were included if they used eye‐tracking to assess the search and detection of lung nodules in computed tomography or 2D radiographic imaging. Data were charted according to identified themes and synthesised using a thematic narrative approach. Results The literature search yielded 25 articles and five themes were discovered: 1 – functional visual field and satisfaction of search, 2 – expert search patterns, 3 – error classification through dwell time, 4 – the impact of the viewing environment and 5 – the effect of prevalence expectation on search. Functional visual field reduced to 2.7° in 3D imaging compared to 5° in 2D radiographs. Although greater visual coverage improved nodule detection, incomplete search was not responsible for missed nodules. Most radiological errors during lung nodule detection were decision‐making errors (30%–45%). Dwell times associated with false‐positive (FP) decisions informed feedback systems to improve diagnosis. Interruptions did not influence diagnostic performance; however, it increased viewing time by 8% and produced a 23.1% search continuation accuracy. Comparative scanning was found to increase the detection of low contrast nodules. Prevalence expectation did not directly affect diagnostic accuracy; however, decision‐making time increased by 2.32 seconds with high prevalence expectations. Conclusion Visual and cognitive factors influence pulmonary nodule detection. Insights gained from eye‐tracking can inform advancements in lung screening. Further exploration of eye‐tracking in lung screening, particularly with low‐dose computed tomography (LDCT), will benefit the future of lung cancer screening., Early detection of malignant pulmonary nodules through screening has been shown to reduce lung cancer‐related mortality by 20%. However, perceptual and cognitive factors that affect nodule detection are poorly understood. This review examines the cognitive and visual processes during lung nodule detection.

This editorial discusses the importance of quality improvement and quality assurance in the provision of medical imaging services, by exploring two studies which aim to improve the quality of practice in emergency departments (ED). The quality of work by ED radiographers are continually planned, measured, assessed, and improved to enhance patient care outcomes – from the accurate diagnosis of patients, maintaining the consistency of diagnostic images, and to minimising radiation exposure to patients.

Introduction Uterine artery embolisation (UAE) is regarded as a safe and effective treatment for symptomatic uterine fibroids and/or adenomyosis. Dose reduction during UAE is critical for this reproductive‐age patient population to minimise the risks of radiation‐induced effects. The aim of this study was to identify the predictors of radiation dose which can be controlled and optimised for patients during UAE. Methods A total of 150 patients between June 2018 and August 2019 were included in this study. Demographic and clinical information such as age, body mass index (BMI), total number of fibroids, total fibroid volume, total uterus volume and dosimetric measurements on Dose Area Product (DAP), Air Kerma (AK) and fluoroscopy time were recorded. Total digital subtraction angiography (DSA), total conventional roadmap (CRM), total last‐image hold (LIH) and total fluoroscopy were calculated from the dose report. Multiple linear regression analysis was used to identify the independent predictor variables of total dose (DAP) using a regression model. Results Total DSA, total CRM and total LIH were identified as the determinants of dose for UAE (P, The predictors of patient radiation dose have been identified for the interventional radiology procedure known as uterine artery embolisation (UAE). A regression model entered and identified total digital subtraction angiography (DSA), total conventional roadmap (CRM) and total last‐image hold (LIH) as the determinants of dose over demographic and other angiographic variables. Control of these dose predictors can potentially minimise radiation dose exposure to this reproductive‐age patient population. Dose optimisation can be attained to reduce the risks of tissue effects and/or stochastic effects associated with irradiating the pelvis region.

Rationale and Objectives To measure the effect of visual hindsight bias on radiologists’ perception during chest radiograph pulmonary nodule detection. Materials and Methods This was a prospective multi-observer study to assess the effect of hindsight bias on radiologists’ perception. Sixteen radiologists were asked to interpret 15 postero-anterior chest images containing a solitary lung nodule each consisting of 25 incremental levels of blur. Participants were requested initially to detect the nodule by reducing the blur of the images (foresight). They were then asked to increase the blur until the identified nodule was undetectable (hindsight). Participants then repeated the experiment, after being informed of the potential effects of hindsight bias and asked to counteract these effects. Participants were divided into two groups (experienced and less experienced) and the nodules were given different conspicuity ratings to determine the effect of expertise and task difficulty. Eye tracking technology was also utilised to capture visual search. Results Wilcoxon analysis demonstrated significant differences between foresight and hindsight values of the radiologists (p = 0.02). However, after being informed of hindsight bias, these differences were no longer significant (p = 0.97). Friedman analysis also determined overall significance in the hindsight ratios between nodule conspicuities for both phases (phase 1: p = 0.02; phase 2: p = 0.02). There was no significance difference between the experienced and less experienced groups. Conclusion This study demonstrated that radiologists exhibit hindsight bias but appeared to be able to compensate for this phenomenon once its effects were considered. Also, visual hindsight bias appears to be affected by task difficulty with a greater effect occurring with less conspicuous nodules.

Studies have shown that the use of artificial intelligence can reduce errors in medical image assessment. The diagnosis of breast cancer is an essential task; however, diagnosis can include ‘detection’ and ‘interpretation’ errors. Studies to reduce these errors have shown the feasibility of using convolution neural networks (CNNs). This narrative review presents recent studies in diagnosing mammographic malignancy investigating the accuracy and reliability of these CNNs. Databases including ScienceDirect, PubMed, MEDLINE, British Medical Journal and Medscape were searched using the terms ‘convolutional neural network or artificial intelligence’, ‘breast neoplasms [MeSH] or breast cancer or breast carcinoma’ and ‘mammography [MeSH Terms]’. Articles collected were screened under the inclusion and exclusion criteria, accounting for the publication date and exclusive use of mammography images, and included only literature in English. After extracting data, results were compared and discussed. This review included 33 studies and identified four recurring categories of studies: the differentiation of benign and malignant masses, the localisation of masses, cancer‐containing and cancer‐free breast tissue differentiation and breast classification based on breast density. CNN's application in detecting malignancy in mammography appears promising but requires further standardised investigations before potentially becoming an integral part of the diagnostic routine in mammography., This article explores the current research and developments in using convolutional neural networks for mammography diagnosis. Current developments are focused on four distinct categories; however, limitations of this artificial intelligence withhold it from clinical implementation.

Uterine artery embolisation (UAE) is an interventional angiography procedure for the treatment of symptomatic fibroids and/or adenomyosis in women. UAE is a less invasive and non‐surgical alternative to hysterectomy or myomectomy. However, ionising radiation is used for both fluoroscopic and angiographic image guidance to visualise and access the uterine arteries for embolisation and treatment of these benign conditions. Identifying the contributors and implementing dose reduction techniques are particularly important as UAE patients are usually of child‐bearing age. The purpose of this review was to examine the progression of literature on radiation exposure measurements and identifying the factors contributing to the total radiation exposure of female patients undergoing UAE. A Medline, ProQuest Central, ScienceDirect and Scopus database search from 2000 to 2018 was performed and forty articles were deemed acceptable for review following the inclusion and exclusion criteria set. UAE is a viable alternative to hysterectomy and myomectomy, as the reviewed literature demonstrated that the reported radiation exposure doses appear to be below the threshold for any deterministic radiation risks. The total radiation exposure of UAE patients is affected independently by multiple patient, operator expertise and technique, angiographic imaging and x‐ray unit variables. Uterus preservation can be attained post‐UAE with dose reduction and optimisation, however, a longitudinal study on UAE patients and their risk of radiation‐induced deterministic and/or stochastic effects is recommended.

Trauma to the facial area accounts for a significant number of admissions to the emergency department. Diagnostic imaging is almost always required, and is critical in determining patient management. Multi‐detector computed tomography (MDCT) appears consistently in the literature as the gold‐standard imaging modality for facial bones, but results in a high radiation dose to the patient. This makes the application and advancement of dose reduction and dose optimisation methods vital. This narrative review presents a critical analysis of the literature concerning diagnostic imaging of facial bone trauma, with an emphasis on dose reduction methods for MDCT. Databases including Pubmed, Medline, Web of Science and Scopus were used to investigate this topic, with the key words: facial bone trauma, computed tomography (CT) imaging and dose reduction. Exclusion criteria included studies on nasal bone fracturing, dental imaging, elective surgeries and paediatric imaging. The literature shows overwhelming support for MDCT, given its accuracy, efficiency and ease of operation. Noise reducing reconstruction algorithms show promise as a successful method of dose reduction in facial bone imaging. Investigations of more innovative techniques also appear within the literature, including diagnostic cone‐beam CT (CBCT), intraoperative CBCT and dual‐source CT (DSCT), but further research is required to confirm their clinical value.

Introduction Radiologists utilise mammography test sets to bench mark their performance against recognised standards. Using a validated test set, this study compares the performance of radiographer readers against previous test results for radiologists. Methods Under similar test conditions radiographer readers were given an established test set of 60 mammograms and tasked to identify breast cancer, they were measured against their ability to identify, locate and give a confidence level for cancer being present on a standard set of mammographic images. The results were then compared to previously published results for radiologists for similar or the same test sets. Results The 10 radiographer readers demonstrated similar results to radiologists and for lesion sensitivity were the highest scoring group. The study group score a sensitivity of 83; a specificity of 69.3 and lesion sensitivity of 74.8 with ROC and JAFROC scores of 0.86 and 0.74 respectively. Conclusion Under test conditions radiographers are able to identify and accurately locate breast cancer in a range of complex mammographic backgrounds. Implications for practice The study was performed under experimental conditions with results comparable to breast radiologists under similar conditions, translation of these findings into clinical practice will help address access and capacity issues in the timely identification and diagnosis of breast cancer.

Rationale and objectives: Target recall rates are often used as a performance indicator in mammography screening programs with the intention of reducing false positive decisions, over diagnosis and anxiety for participants. However, the relationship between target recall rates and cancer detection is unclear, especially when readers are directed to adhere to a predetermined rate. The purpose of this study was to explore the effect of setting different recall rates on radiologist’s performance. Materials and Methods: Institutional ethics approval was granted and informed consent was obtained from each participating radiologist. Five experienced breast imaging radiologists read a single test set of 200 mammographic cases (20 abnormal and 180 normal). The radiologists were asked to identify each case that they required to be recalled in three different recall conditions; free recall, 15% and 10% and mark the location of any suspicious lesions. Results: Wide variability in recall rates was observed when reading at free recall, ranging from 18.5% to 34.0%. Readers demonstrated significantly reduced performance when reading at prescribed recall rates, with lower sensitivity (H=12.891, P=0.002), case location sensitivity (H=12.512, P=0.002) and ROC AUC (H=11.601, P=0.003) albeit with an increased specificity (H=12.704, P=0.002). However, no significant changes were evident in lesion location sensitivity (H=1.982, P=0.371) and JAFROC FOM (H=1.820, P=0.403). Conclusion: In this laboratory study, reducing the number of recalled cases to 10% significantly reduced radiologists’ performance with lower detection sensitivity, although a significant improvement in specificity was observed.

AIM To measure the level of radiologists' performance in lung cancer detection, and to explore radiologists' performance in cancer specialised and non-specialised centres. MATERIALS AND METHODS Thirty radiologists read 60 chest computed tomography (CT) examinations. Thirty cases had surgically or biopsy-proven lung cancer and 30 were cancer-free cases. The cancer cases were validated by four expert radiologists who located the malignant lung nodules. Reader performance was evaluated by calculating sensitivity, location sensitivity, specificity, and area under the receiver operating characteristic (ROC) curve (AUC). In addition, sensitivity at fixed specificity (0.794) was computed from each reader's estimated ROC curve. RESULTS The radiologists had a mean sensitivity of 0.749, sensitivity at fixed specificity of 0.744, location sensitivity of 0.666, specificity of 0.81 and AUC of 0.846. Radiologists in the specialised and non-specialised cancer centres had the following (specialised, non-specialised) pairs of values: sensitivity=(0.80, 0.719); sensitivity for fixed 0.794 specificity=(0.752, 0.740); location sensitivity=(0.712, 0.637); specificity=(0.794, 0.82) and AUC=(0.846, 0.846). CONCLUSION The efficacy of radiologists was comparable to other studies. Furthermore, AUC outcomes were similar for specialised and non-specialised cancer centre radiologists, suggesting they have similar discriminatory ability and that the higher sensitivity and lower specificity for specialised-centre radiologists can be attributed to them being less conservative in interpreting case images.

Introduction An ideal organ‐specific insert phantom should be able to simulate the anatomical features with appropriate appearances in the resultant computed tomography (CT) images. This study investigated a 3D printing technology to develop a novel and cost‐effective cardiac insert phantom derived from volumetric CT image datasets of anthropomorphic chest phantom. Methods Cardiac insert volumes were segmented from CT image datasets, derived from an anthropomorphic chest phantom of Lungman N‐01 (Kyoto Kagaku, Japan). These segmented datasets were converted to a virtual 3D‐isosurface of heart‐shaped shell, while two other removable inserts were included using computer‐aided design (CAD) software program. This newly designed cardiac insert phantom was later printed by using a fused deposition modelling (FDM) process via a Creatbot DM Plus 3D printer. Then, several selected filling materials, such as contrast media, oil, water and jelly, were loaded into designated spaces in the 3D‐printed phantom. The 3D‐printed cardiac insert phantom was positioned within the anthropomorphic chest phantom and 30 repeated CT acquisitions performed using a multi‐detector scanner at 120‐kVp tube potential. Attenuation (Hounsfield Unit, HU) values were measured and compared to the image datasets of real‐patient and Catphan® 500 phantom. Results The output of the 3D‐printed cardiac insert phantom was a solid acrylic plastic material, which was strong, light in weight and cost‐effective. HU values of the filling materials were comparable to the image datasets of real‐patient and Catphan® 500 phantom. Conclusions A novel and cost‐effective cardiac insert phantom for anthropomorphic chest phantom was developed using volumetric CT image datasets with a 3D printer. Hence, this suggested the printing methodology could be applied to generate other phantoms for CT imaging studies.

Three‐dimensional (3D) printing technology has demonstrated a huge potential for the future of medicine. Since its introduction, it has been used in various areas, for example building anatomical models, personalising medical devices and implants, aiding in precision medical interventions and the latest development, 3D bioprinting. This commentary is provided to outline the current use of 3D printing in medical imaging and its future directions for advancing the healthcare services.

Background: Lung cancer, the leading cause of cancer death worldwide, can be survived if early detection through screening programs occurs. However if a large scale lung cancer screening program needs to be implemented, it may require a substantial increase in qualified readers’ numbers. To investigate whether senior radiology residents may potentially increase the pool of available readers in screening for lung cancer, by comparing their performance with that of board-certified radiologists. Methodology: Twenty board-certified radiologists and ten senior residents read sixty chest CT scans. Thirty cases had surgically or biopsy-proven lung cancer and the remaining thirty were cancer-free cases. The cancer cases were validated by four expert radiologists who located the malignant lung nodules. Reader performance was evaluated by calculating sensitivity, location sensitivity, specificity, area under the receiver-operating-characteristic curve (AUC) and sensitivity at fixed specificity = 0.8. Results: Readers had the following (radiologists, residents) pairs of values: sensitivity = (0.782, 0.687); location sensitivity = (0.702, 0.597); specificity = (0.8, 0.83); AUC = (0.844, 0.85) and sensitivity for fixed 0.8 specificity = (0.74, 0.73). Conclusion: Initial findings suggest that senior residents compare favorably with board-certified radiologists based on the similarity of the AUCs and the summary ROC curves in terms of the ability to discriminate between diseased and non-diseased patients. However, they have demonstrated significantly lower detection sensitivity than board-certified radiologists and may require additional training, considering the importance of having high sensitivity when screening for cancer.

This experiment investigated whether there might be an effect on the visual search strategy of radiologists during image interpretation of the same adult chest radiographs when given different clinical information. Each of 17 experienced radiologists was asked to interpret a set of 57 (10 abnormal) posteroanterior chest images to identify the presence of pulmonary lesions using differing clinical information (leading to unknown, low and high expectations of prevalence). Eye position metrics (search time, dwell time and time to first fixation) were compared for normal and abnormal images, as well as between conditions. For all images, there was a significantly longer search time at high prevalence expectation compared to low prevalence expectation (W = 75.19, P =

Rationale and Objectives This research investigates whether an expectation of abnormality and prior knowledge might potentially influence the decision-making of radiologists, and discusses the implications for radiological expert witness testimony. Materials and Methods This study was a web-based perception experiment. A total of 12 board-certified radiologists were asked to interpret 40 adult chest images (20 abnormal) twice and decide if pulmonary lesions were present. Before the first viewing, a general clinical history was given for all images: cough for 3 + weeks . This was called the “defendants read.” Two weeks later, the radiologists were asked to view the same dataset (unaware that the dataset was unchanged). For this reading, the radiologists were given the following information for all images: “ These images were reported normal but all of these patients have a lung tumour diagnosed on a subsequent radiograph 6 months later. ” They were also given the lobar location of the newly diagnosed tumor. This was called the “expert witness read.” Results There was a significant difference in location-based sensitivity (W = −45, P = 0.02) between the two conditions with nodule detection increasing under the second condition. Specificity increased outside the lobe of interest (W = 727, P = P = 0.03) significantly in the “expert witness” read. Case-based sensitivity and case-based specificity were unaffected. Conclusions This study showed evidence that increased clinical information affects the performance of radiologists. This effect may bias expert witnesses in radiological malpractice litigation.

Rationale and Objectives The aim of this study was to measure the effect of prevalence expectation as determined by clinical history on the diagnostic performance of radiologists during pulmonary nodule detection on adult chest radiographs. Materials and Methods A multi-observer, counter-balanced study (having half the readers in each group read a different condition initially) was performed to assess the effect of abnormality expectation on experienced radiologists' performance. A total of 33 board-certified radiologists were divided into three groups and searched for evidence of malignancy on a single set of 47 postero-anterior (PA) chest radiographs, 10 of which contained a single pulmonary nodule. The radiologists were unaware of disease prevalence. Before each viewing of the same dataset, the radiologists were allocated to two of three conditions based on the differing clinical information (previous cancer, no history, visa applicant). Location sensitivity, specificity, and jack-knife free-response receiver operator characteristics figure of merit were used to compare radiologist performance between conditions. Results A significant reduction in specificity was shown for the cancer compared to that for the visa condition (W = −41 P = 0.02). No other significant findings were demonstrated for this or the other condition comparisons. No significant difference in the performance of radiologists was noted when viewing images under the same conditions. Conclusions This study suggested that there is a reduction in specificity with high compared to low prevalence expectation following specific radiological contexts. A reduction in specificity can have important clinical consequences leading to unnecessary interventions. The results and their implications emphasize the caution that should be placed on providing accurate referral criteria.

Objectives: This work establishes the prototype of a new innovative risk model that aims to evaluate the total risk involved with screening mammography for each individual female. This has been specifically designed to accommodate any combination of lifetime screening regimes, using only the information gathered from a single mammographic examination. Methods: This model prototype was developed with the aid of a large dataset of images from the Cancer Institute New South Wales (CINSW) with over 30,000 images from over 7000 examinations. Each examination is derived from a separate female. Results: This prototype which we have called Breast Individualised Risk of Radiation-Induced Screening Cancer (Breast-iRRISC) is a novel tool for the assessment of the lifetime risk involved with screening mammography. The results demonstrate the applicability of this approach to the various screening regimes utilised around the globe, in addition to the personalised screening frequency patterns females have undergone and are likely to receive in the future. Conclusions: This unique tailored approach to risk assessment will further empower females and clinicians towards a more informed clinical decision process regarding future imaging pathways. It will also inform health policy decisions regarding alternate screening durations and intervals. Advances in knowledge: Breast-iRRISC is a novel tool that provides females, clinicians and health policymakers around the globe with the ability to quantify the lifetime risk of radiation-induced breast cancer from screening mammography on an individual level from a single exposure.

Recall rates are one of the performance measures used to evaluate the effectiveness of mammography screening programs. There is conflicting evidence regarding the link between recall rates and cancer detection rates and a variety of differing recall rates exist between countries and readers. This variability in recall rates may have important clinical and economic implications such as unnecessary follow-up procedures, additional costs to the health care system and psychological effects for the women themselves associated with false-positive mammograms results. In order to reduce the impact of false positive recall rates in screening mammography, it is essential for all multidisciplinary health care providers, especially those in medical imaging, to fully understand the factors that may contribute and affect recall rates. The multifactorial nature of recall rates is explored in this paper through the construction of a conceptual map based on a review of the current literature.

Penetrating brain injuries (PBI) are a medical emergency, often resulting in complex damage and high mortality rates. Neuroimaging is essential to evaluate the location and extent of injuries, and to manage them accordingly. Currently, a myriad of imaging modalities are included in the diagnostic workup for adult PBI, including skull radiography, computed tomography (CT), magnetic resonance imaging (MRI) and angiography, with each modality providing their own particular benefits. This literature review explores the current modalities available for investigating PBI and aims to assist in decision making for the appropriate use of diagnostic imaging when presented with an adult PBI. Based on the current literature, the authors have developed an imaging pathway for adult penetrating brain injury that functions as both a learning tool and reference guide for radiographers and other health professionals. Currently, CT is recommended as the imaging modality of choice for the initial assessment of PBI patients, while MRI is important in the sub-acute setting where it aids prognosis prediction and rehabilitation planning, Additional follow-up imaging, such as angiography, should be dependent upon clinical findings.

This study investigated whether certain mammographic appearances of breast cancer are missed when radiologists read at lower recall rates.5 radiologists read 1 identical test set of 200 mammographic (180 normal cases and 20 abnormal cases) 3 times and were requested to adhere to 3 different recall rate conditions: free recall, 15% and 10%. The radiologists were asked to mark the locations of suspicious lesions and provide a confidence rating for each decision. An independent expert radiologist identified the various types of cancers in the test set, including the presence of calcifications and the lesion location, including specific mammographic density.Radiologists demonstrated lower sensitivity and receiver operating characteristic area under the curve for non-specific density/asymmetric density (H = 6.27, p = 0.04 and H = 7.35, p = 0.03, respectively) and mixed features (H = 9.97, p = 0.01 and H = 6.50, p = 0.04, respectively) when reading at 15% and 10% recall rates. No significant change was observed on cancer characterized with stellate masses (H = 3.43, p = 0.18 and H = 1.23, p = 0.54, respectively) and architectural distortion (H = 0.00, p = 1.00 and H = 2.00, p = 0.37, respectively). Across all recall conditions, stellate masses were likely to be recalled (90.0%), whereas non-specific densities were likely to be missed (45.6%).Cancers with a stellate mass were more easily detected and were more likely to continue to be recalled, even at lower recall rates. Cancers with non-specific density and mixed features were most likely to be missed at reduced recall rates. Advances in knowledge: Internationally, recall rates vary within screening mammography programs considerably, with a range between 1% and 15%, and very little is known about the type of breast cancer appearances found when radiologists interpret screening mammograms at these various recall rates. Therefore, understanding the lesion types and the mammographic appearances of breast cancers that are affected by readers' recall decisions should be investigated.

Rationale and Objectives To investigate the impact of breast density on the performance of radiologists when mammograms are digitally acquired and displayed. Materials and Methods A total of 150 craniocaudal digital mammograms including 75 cases with cancer were examined by 14 radiologists divided into two groups: those who read more (six) and less (eight) than 2000 mammograms per year. Cases were classified as low or high mammographic density. For both types of cases, detection of cancers within and outside the dense fibroglandular tissue was investigated. The performance of radiologist was measured using jack-knife free-response receiver operating characteristic (JAFROC) figure of merit (FOM). Results Radiologists with over 2000 annual reads had significantly higher JAFROC FOM (P = .03) for high (0.76) mammographic density compared to low (0.70) mammographic density cases. When lesions overlaid the fibroglandular tissue, cases with high mammographic density compared to low mammographic density displayed increased location sensitivity for all radiologists (P = .03) and for those radiologists reading more than 2000 mammograms annually (P = .04), whereas JAFROC FOMs increased for all radiologists (P = .05). No significant changes were observed when the lesion was outside the fibroglandular region. Conclusions Increased mammographic density improves the performance of experienced radiologists when using digital mammograms. This finding, which does not align with those previously reported for film screen systems, may be because of windowing/leveling opportunities available with digital images.

This study aims to explore Australian radiologists' experiences of participating in breast cancer multi-disciplinary team (MDT) meetings to identify enablers and barriers to participation as well their perception of confidence and patient care. Qualitative methods incorporating observation and interviews were used. Twenty-one breast cancer MDT meetings were observed across Sydney to study the dynamics of the meetings, the level of participation by radiologists and their most important interactions. Qualitative semi-structured interviews were conducted with 10 radiologists participating in these meetings regarding participation, educational opportunities and improvements to work practices. Radiologists' participation in breast cancer MDT meetings is influenced by the type of meeting they attend with higher levels of participation and a more dominant ‘valued’ role being evident in pre-interventional meetings. The key themes to emerge from the data include the importance of ‘sharing experiences’, the ‘radiologist–pathologist relationship’ and the value of ‘continuing participation’. Radiologists believed their confidence in their clinical decision making increased when there was immediate feedback from pathologists. This study highlights the benefits of radiologists regularly participating in breast cancer MDT meetings in terms of continuing professional education resulting from collegial experiential learning. Radiologists' perceived patient care and workplace isolation were improved by sharing experiences with other cancer care colleagues.

To explore relationships between reader performance and reader characteristics in mammography for specific radiologist groupings on the basis of annual number of readings.The institutional review board approved the study and waived the need for patient consent to use all images. Readers gave informed consent. One hundred sixteen radiologists independently reviewed 60 mammographic cases: 20 cases with cancer and 40 cases with normal findings. Readers located any visualized cancer, and levels of confidence were scored from 1 to 5. A jackknifing free response operating characteristic (JAFROC) method was used, and figures of merit along with sensitivity and specificity were correlated with reader characteristics by using Spearman techniques and standard multiple regressions.Reader performance was positively correlated with number of years since qualification as a radiologist (P ≤ .01), number of years reading mammograms (P ≤ .03), and number of readings per year (P ≤ .0001). The number of years since qualification as a radiologist (P ≤ .004) and number of years of reading mammograms (P ≤ .002) were negatively related to JAFROC values for radiologists with annual volumes of less than 1000 mammographic readings. For individuals with more than 5000 mammographic readings per year, JAFROC values were positively related to the number of years that the reader was qualified as a radiologist (P ≤ .01), number of years of reading mammograms (P ≤ .002), and number of hours per week of reading mammograms (P ≤ .003). Number of mammographic readings per year was positively related with JAFROC scores for readers with an annual volume between 1000 and 5000 readings (P ≤ .03). Differences in JAFROC scores appear to be more related to specificity than location sensitivity, with the former demonstrating significant relationships with four of the five characteristics analyzed, whereas no relationships were shown for the latter.Radiologists' determinants of performance are associated with annual reading volumes. Ability to recognize normal images is a discriminating factor in individuals with a high volume of mammographic readings.

To establish the extent to which test set reading can represent actual clinical reporting in screening mammography.Institutional ethics approval was granted, and informed consent was obtained from each participating screen reader. The need for informed consent with respect to the use of patient materials was waived. Two hundred mammographic examinations were selected from examinations reported by 10 individual expert screen readers, resulting in 10 reader-specific test sets. Data generated from actual clinical reports were compared with three test set conditions: clinical test set reading with prior images, laboratory test set reading with prior images, and laboratory test set reading without prior images. A further set of five expert screen readers was asked to interpret a common set of images in two identical test set conditions to establish a baseline for intraobserver variability. Confidence scores (from 1 to 4) were assigned to the respective decisions made by readers. Region-of-interest (ROI) figures of merit (FOMs) and side-specific sensitivity and specificity were described for the actual clinical reporting of each reader-specific test set and were compared with those for the three test set conditions. Agreement between pairs of readings was performed by using the Kendall coefficient of concordance.Moderate or acceptable levels of agreement were evident (W = 0.69-0.73, P.01) when describing group performance between actual clinical reporting and test set conditions that were reasonably close to the established baseline (W = 0.77, P.01) and were lowest when prior images were excluded. Higher median values for ROI FOMs were demonstrated for the test set conditions than for the actual clinical reporting values; this was possibly linked to changes in sensitivity.Reasonable levels of agreement between actual clinical reporting and test set conditions can be achieved, although inflated sensitivity may be evident with test set conditions.

Introduction Optimal arterial opacification is crucial in imaging the pulmonary arteries using computed tomography (CT). This poses the challenge of precisely timing data acquisition to coincide with the transit of the contrast bolus through the pulmonary vasculature. The aim of this quality assurance exercise was to investigate if a change in CT pulmonary angiography (CTPA) scanning protocol resulted in improved opacification of the pulmonary arteries. Comparison was made between the smart prep protocol (SPP) and the test bolus protocol (TBP) for opacification in the pulmonary trunk. Methods A total of 160 CTPA examinations (80 using each protocol) performed between January 2010 and February 2011 were assessed retrospectively. CT attenuation coefficients were measured in Hounsfield Units (HU) using regions of interest at the level of the pulmonary trunk. The average pixel value, standard deviation (SD), maximum, and minimum were recorded. For each of these variables a mean value was then calculated and compared for these two CTPA protocols. Results Minimum opacification of 200 HU was achieved in 98% of the TBP sample but only 90% of the SPP sample. The average CT attenuation over the pulmonary trunk for the SPP was 329 (SD = ±21) HU, whereas for the TBP it was 396 (SD = ±22) HU (P = 0.0017). The TBP also recorded higher maximum (P = 0.0024) and minimum (P = 0.0039) levels of opacification. Conclusion This study has found that a TBP resulted in significantly better opacification of the pulmonary trunk than the SPP.

Objective To identify specific mammographic appearances that reduce the mammographic detection of breast cancer. Materials and Methods This study received institutional board review approval and all readers gave informed consent. A set of 60 mammograms each consisting of craniocaudal and mediolateral oblique projections were presented to 129 mammogram Breastscreen readers. The images consisted of 20 positive cases with single and multicentric masses in 16 and 4 cases, respectively (resulting in a total of 24 cancers), and readers were asked to identify and locate the lesions. Each lesion was then ranked according to a detectability rating (ie, the number of observers who correctly located the lesion divided by the total number of observers), and this was correlated with breast density, lesion size, and various descriptors of lesion shape and texture. Results Negative and positive correlations between lesion detection and density (r = −0.64, P = .007) and size (r = 0.65, P = .005), respectively, were demonstrated. In terms of lesion size and shape, there were significant correlations between the probability of detection and area (r = 0.43, P = .04), perimeter (r = 0.66, P = .0004), lesion elongation (r = 0.49, P = .02), and lesion nonspiculation (r = 0.78, P Conclusions The results of this study have identified specific lesion characteristics associated with shape that may contribute to reduced cancer detection. Mammographic sensitivity may be adversely affected without appropriate attention to spiculation.

This study measured reading workstation monitors and the viewing environment currently available within BreastScreen New South Wales (BSNSW) centres to determine levels of adherence to national and international guidelines. Thirteen workstations from four BSNSW service centres were assessed using the American Association of Physicists in Medicine Task Group 18 Quality Control test pattern. Reading workstation monitor performance and ambient light levels when interpreting screening mammographic images were assessed using spectroradiometer CS-2000 and chroma meter CL-200. Overall, radiologic monitors within BSNSW were operating at good acceptable levels. Some non-adherence to published guidelines included the percentage difference in maximum luminance between pairs of primary monitors at individual workstations (61.5 % or 30.8 % of workstations depending on specific guidelines), maximum luminance (23.1 % of workstations), luminance non-uniformity (11.5 % of workstations) and minimum luminance (3.8 % of workstations). A number of ambient light measurements did not comply with the only available evidence-based guideline relevant to the methodology used in this study. Larger ambient light variations across sites are shown when monitors were switched off, suggesting that differences in ambient lighting between sites can be masked when a standard mammogram is displayed for photometric measurements. Overall, BSNSW demonstrated good adherence to available guidelines, although some non-compliance has been shown. Recently updated United Kingdom and Australian guidelines should help reduce confusion generated by the plethora and sometimes dated nature of currently available recommendations.

Rationale and Objectives: This study will investigate the link between radiologists’ experience in reporting mammograms, their caseloads and the decision to give a classification of Royal Australian and New Zealand College of Radiologists (RANZCR) category ‘3’ (indeterminate or equivocal finding). Methods: A test set of 60 mammograms comprising of 20 abnormal and 40 normal cases were shown to 92 radiologists. Each radiologist was asked to identify and localize abnormalities and provide a RANZCR assessment category. Details were obtained from each reader regarding their experience, qualifications and breast reading activities. ‘Equivocal fractions’ were calculated by dividing the number of ‘equivocal findings’ given by each radiologist in the abnormal and normal cases by the total number of cases analyzed: 20 and 40 respectively. The ‘equivocal fractions’ for each of the groups (normal vs abnormal) were calculated and independently correlated with age, number of years since qualification as a radiologist, number of years reading mammograms, number of mammograms read per year, number of hours reading mammograms per week and number of mammograms read over lifetime (the number of years reading mammograms multiplied by the number of mammograms read per year). The non-parametric Spearman test was used. Results: Statistically negative correlations were noted between ‘equivocal fractions’ for the following groups: • For abnormal cases: hours per week (r= -0.38 P= 0.0001) • For normal cases: total number of mammograms read per year (r= -0.29, P= 0.006); number of mammograms read over lifetime (r= -0.21, P= 0.049)); hours reading mammograms per week (r= - 0.20, P= 0.05). Conclusion: Radiologists with greater reading experience assign fewer RANZCR category 3 or equivocal classifications. The findings have implications for screening program efficacy and recall rates. This work is still in progress and further data will be presented at the conference.

Purpose: For pregnant patients the imaging choice between computed tomography pulmonary angiography (CTPA) and ventilation-perfusion scintigraphy (VQ) in the investigation of pulmonary emboli (PE) is clouded by perceptions of radiation dose levels reaching the foetus. There is also uncertainty amongst medical professionals regarding the subsequent need to implement measures directed at reducing this dose. The aim of this article is to clarify the various theories surrounding CTPA of the pregnant patient and provide radiographers and medical professionals with a clear, concise understanding of how to reduce the radiation dose to the foetus during CTPA scanning. Methods: In a review of the current data surrounding foetal doses in relation to CTPA this paper is able to compare CTPA and VQ foetal doses. By collating information from the limited number of studies performed on foetal dose reduction techniques for CTPA a number of conclusions were drawn in order to formulate a scanning guide for radiographers. Results: Current opinion suggests that the benefits of CTPA outweigh those of VQ with respect to foetal radiation dose. Survey evidence suggests that oft en no foetal dose reduction strategies are implemented when scanning a pregnant woman for CTPA. Recently published studies have shown that simply by altering the CTPA scanning parameters, such as kVp, mAs, and scan length, using lead protection on the abdomen, and even ingesting barium sulphate solution the dose received by the foetus can be reduced by at least half. Conclusion: Since the stochastic effects of radiation are relatively unknown it is prudent to use any practical techniques aimed at reducing the foetal dose during a CTPA study. Since most of the measures investigated are practical and cause little patient discomfort the authors suggest that consideration should be given to integrating these modifications into current routine scanning protocols.

Adverse delayed reactions (ADRs) to the intravenous injection of non-ionic iodinated contrast media (NICM) were fi rst recognised in the mid-1980s and a growing number of articles in the literature have described such reactions as increasingly common. Th e aim of this article is to increase the understanding of the risk factors, frequency, signs and symptoms of ADRs amongst healthcare staff especially radiographers, nurses, radiologists and physicians who regularly use contrast media (CM). A literature review of multiple studies assessing ADRs performed from 1990-2010 has revealed various misconceptions, particularly in the frequency of ADRs and the infl uence of ethnic background most likely due to methodological limitations. Th erefore, the use of improved research methods and design has the potential to increase our knowledge in this area. Furthermore, new areas of study such as blood testing as a screening tool can assist in risk assessment and prevention of ADRs.

To measure the effect of abnormality-prevalence expectation on experienced radiologists' performance during pulmonary nodular lesion detection on a chest radiograph.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.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).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.

Purpose: This study investigated advanced practices carried out by radiographers in New South Wales (NSW). Background: Due to a chronic shortage of radiologists, radiographers in the United Kingdom have extended their clinical roles. These additional responsibilities have increased professional accountability, as well as improved the quality of care provided to patients. While it is likely that such professional role extension occurs in Australia, no known study has been performed to date on this topic. Methods: Questionnaires were mailed to Chief Radiographers of medical imaging departments (MIDs) across NSW. Questions related to MIDs demographics and advanced practices of radiographers including triage systems, formal and informal reporting, cannulation, intravenous contrast media administration, roles during diagnostic enemas, and involvement in research. Returned questionnaires were analysed. Results: A total of 69 questionnaires were returned from 115 distributed (60%). Seventeen percent of MIDs with an Emergency department had radiographers involved in the triage process; 39% of MIDs utilised a radiographer-reported abnormality detection system, whilst 30% provided a verbal report. Radiographer-performed cannulations and intravenous contrast media administration occurred in 77% and 79% of MIDs respectively. A total of 40% reported radiographers performing roles other than image acquisition during diagnostic enemas, radiographers participated in research in 13% of MIDs while radiographer clinical presentations, journal club participation and conference organisation occurred in 45%, 7%, and 38% of MIDs respectively. Conclusions: This exploratory study provides important baseline information on the extended roles of radiographers in NSW. The results could be used for future planning of radiographer roles and health service delivery techniques.

Rationale and Objectives To determine the relationship between heightened levels of reader performance and reader practice in terms of number of cases read and previous experience. Materials and Methods A test set of mammograms was developed comprising 50 cases. These cases consisted of 15 abnormals (biopsy proven) and 35 normals (confirmed at subsequent rescreen). Sixty-nine breast image readers reviewed these cases independently and their performance was measured by recording their individual receiver operating characteristic score (area under the curve), sensitivity, and specificity. These measures of performance were then compared to a range of factors relating to the reader such as years of certification and reporting, number of cases read per year, previous experiences, and satisfaction levels. Correlation analyses using Spearman methods were performed along with the Mann-Whitney test to detect differences in performance between specific reader groups. Results Improved reader performance was found for years certified (P = .004), years of experience (P = .0001), and hours reading per week (P = .003) shown by positive statistical significant relationships with Az values (area under receiver operating characteristic curve). Statistical comparisons of Az values scored for individuals who read varying number of cases per year showed that those individuals whose annual mammographic case load was 5000 or more (P = .03) or between 2000 and 4999 (P = .05), had statistically significantly higher scores than those who read less than 1000 cases per year. Conclusion The results of this study have shown variations in reader performance relating to parameters of reader practice and experience. Levels of variance are shown and potential acceptance levels for diagnostic efficacy are proposed which may inform policy makers, judicial systems and public debate.

Coronary angioplasties can be performed with either single-plane or biplane imaging techniques. The aim of this study was to determine whether biplane imaging, in comparison to single-plane imaging, reduces radiation dose and contrast load and shortens procedural time during (i) primary and elective coronary angioplasty procedures, (ii) angioplasty to the main vascular territories and (iii) procedures performed by operators with various levels of experience. This prospective observational study included a total of 504 primary and elective single-vessel coronary angioplasty procedures utilising either biplane or single-plane imaging. Radiographic and clinical parameters were collected from clinical reports and examination protocols. Radiation dose was measured by a dose-area-product (DAP) meter intrinsic to the angiography system. Our results showed that biplane imaging delivered a significantly greater radiation dose (181.4+/-121.0 Gycm(2)) than single-plane imaging (133.6+/-92.8 Gycm(2), p

A method was sought by which to measure the cortical thickness of long bones, as a prelude to a large comparative study of cortical bone thickness. Radiography presents a simple, non-destructive method for visualising internal features of bones. Radiogrammetry, though frequently used for cortical bone measurements, has predominantly focused on the metacarpals in the literature, while studies examining the method for large long bones are less plentiful. The tibia was used in this study, with samples from humans, kangaroos, sheep, dogs, pigs and cattle. Digital radiographs were obtained from the anterior and medial sides of the bone; images were then displayed on screen, magnified and measured. Bone diameter, medulla diameter and cortical thickness were measured for each projection, at the midpoint of the tibia. Some difficulty was encountered due to the lack of clarity of the endosteal border of the cortex, though intra-observer tests found the method to be largely reproducible. Magnification and distortion of the image were observed, particularly on larger bones as they were situated a greater distance above the film surface. These factors were not considered too limiting; furthermore, the simplicity of the method means it would be generally suitable for the proposed study.

Purpose: Through a study of the literature this paper aims to investigate the imaging pathway which should be undertaken by patients presenting to the emergency department with renal colic and flank pain. Method: The British Journal of Radiology, Journal of Endourology, Radiology, RadioGraphics, American Journal of Radiology and Adult Urology were searched to find any previous studies into this area through the use of keywords: calculi, renal, computed tomography (CT), plain imaging, abdominal, ultrasound, intravenous urogram (IVU) and x-ray. Conclusion: This literature review determined that the use of non-enhanced helical CT scanning of the abdomen and pelvis should be utilised as the initial imaging technique. CT is able to demonstrate all stones, can be performed rapidly and can diagnose other pathologies which may be mimicking renal colic. Plain film and contrast imaging studies including intravenous urography (IVU) are seen as being of little diagnostic value for frontline identification due to their inability to demonstrate a large number of stones due to size, location and composition. Ultrasound has been shown to be of use as a tool for pregnant or paediatric patients, however its inability to accurately demonstrate the ureters and diagnose extra-urinary pathology limits its use for the general population. The use of low-dose CT is also discussed, and its use advocated for patients with repeat presentation of these symptoms. As more education is provided into this area, the authors believe this will become the modality and technique of choice. An imaging pathway flowchart devised by this review is provided.

Higher recall rates have been related to increased false positive decisions, causing significant psychological and economical costs for both screened women and the mammography screening service respectively. This study compares breast readers' performance in a laboratory setting under varying levels of recall rates. Four experienced radiologists volunteered to read a single test set of 200 mammographic cases over three separate conditions. The test set contained of 180 normal and 20 abnormal cases and the participants were asked to identify each case that required to be recalled in line with three different target recall rates: control unspecified or free recall first read, 15i¾?% second read and 10i¾?% third read. Readers were required to mark the location of any malignancies using custom made detection software. The recall rates for the control condition ranged between 18.5i¾?% and 34i¾?%. Statistically significant differences were observed in sensitivity for control mediani¾?=i¾?0.85 vs 15i¾?% mediani¾?=i¾?0.65, zi¾?=i¾?-2.381, Pi¾?=i¾?0.017, 15i¾?% vs 10i¾?% mediani¾?=i¾?0.55, zi¾?=i¾?-2.428, Pi¾?=i¾?0.015 and control vs 10i¾?% zi¾?=i¾?-2.381, Pi¾?=i¾?0.017. ROC AUC was significantly different for control mediani¾?=i¾?0.84 vs 15i¾?% mediani¾?=i¾?0.79, zi¾?=i¾?-2.381, Pi¾?=i¾?0.017 and 15i¾?% vs 10i¾?% mediani¾?=i¾?0.75, zi¾?=i¾?-2.381, Pi¾?=i¾?0.017. Specificity significantly improved at lower recall rate of 10i¾?% mediani¾?=i¾?0.95 vs 15i¾?% mediani¾?=i¾?0.92, zi¾?=i¾?-2.428, Pi¾?=i¾?0.017. Setting specific target recall rates for readers significantly limited their performance in correctly identifying cancers. In this study, decreasing the number of recalled cases down to 10i¾?%, significantly reduced cancer detection, with a significant improvement in specificity Pi¾?≤i¾?0.05.

Aim: To investigate the perceptions of radiographers in the Greater Sydney metropolitan area concerning the performance of intravenous contrast media injections by radiographers. Methods: 90 radiographers (corresponds to a 40.9% return) from five randomly selected private radiology practices and five randomly selected public hospitals within the Greater Sydney metropolitan area were surveyed. The survey was structured such that each section of the survey related to a specific objective of the study. This study focuses on training, departmental workflow and medicolegal issues. Results: Radiographers from private practices were more in favour of performing intravenous contrast media administration, although the majority of the radiographers surveyed felt that it should be performed as part of their normal duties. They felt that it would greatly aid department workflow and patient throughput. However, there were concerns about the medicolegal implications of this added responsibility. Conclusions: Most respondents were in favour of radiographers performing contrast media injections. Standardised and accredited training, including education on the medicolegal coverage available to them, may be needed to allay their concerns and adequately prepare them to take on this extended role. (author abstract)

The aim of this systematic review is to evaluate the radiation dose reduction achieved using iterative reconstruction (IR) compared to filtered back projection (FBP) in coronary CT angiography (CCTA) and assess the impact on diagnostic image quality. A systematic search of seven electronic databases was performed to identify all studies using a developed keywords strategy. A total of 14 studies met the criteria and were included in a review analysis. The results showed that there was a significant reduction in radiation dose when using IR compared to FBP (P 0.05). The mean and standard deviation (SD) difference of CTDIvol and dose-length-product (DLP) were 14.70 ± 6.87 mGy and 186 ± 120 mGy.cm respectively. The mean ± SD difference of effective dose (ED ) was 2.9 ± 1.7 mSv with the range from 1.0 to 5.0 mSv. The assessment of diagnostic image quality showed no significant difference (P 0.05). The mean ± SD difference of image noise, signal-noise ratio (SNR) and contrast-noise ratio (CNR) were 1.05 ± 1.29 HU, 0.88 ± 0.56 and 0.63 ± 1.83 respectively. The mean ± SD percentages of overall image quality scores were 71.79 ± 12.29% (FBP) and 67.31 ± 22.96% (IR). The mean ± SD percentages of coronary segment analysis were 95.43 ± 2.57% (FBP) and 97.19 ± 2.62% (IR). In conclusion, this review analysis shows that CCTA with the use of IR leads to a significant reduction in radiation dose as compared to the use of FBP. Diagnostic image quality of IR at reduced dose (30-41%) is comparable to FBP at standard dose in the diagnosis of CAD.

The task of identifying fragments of long bone shafts as human or non-human is difficult but necessary, for both forensic and archaeological cases, and a fast simple method is particularly useful. Previous literature suggests there may be differences in the thickness of the cortical bone between these two groups, but this has not been tested thoroughly. The aim of this study was not only to test this suggestion, but also to provide data that could be of practical assistance for future comparisons. The major limb bones (humerus, radius, femur and tibia) of 50 Caucasoid adult skeletons of known age and sex were radiographed, along with corresponding skeletal elements from sheep, pigs, cattle, large dogs and kangaroos. Measurements were taken from the radiographs at five points along the bone shaft, of shaft diameter, cortical bone thickness, and a cortical thickness index (sum of cortices divided by shaft diameter) in both anteroposterior and mediolateral orientations. Each variable for actual cortical bone thickness as well as cortical thickness indices were compared between the human group (split by sex) and each of the non-human groups in turn, using Student's t-tests. Results showed that while significant differences did exist between the human groups and many of the non-human groups, these were not all in the same direction. That is, some variables in the human groups were significantly greater than, and others were significantly less than, the corresponding variable in the non-human groups, depending on the particular non-human group, sex of the human group, or variable under comparison. This was the case for measurements of both actual cortical bone thickness and cortical thickness index. Therefore, for bone shaft fragments for which the skeletal element is unknown, the overlap in cortical bone thickness between different areas of different bones is too great to allow identification using this method alone. However, by providing extensive cortical bone thickness data for a range of bones, this study may be able to assist in the identification of some bone fragments by providing another piece of evidence that, used in conjunction with other clues, can provide a likely determination of the origin of a bone fragment.

Rationale and Objectives: To investigate the effect of inserting obvious cancers into a screening set of mammograms on the visual search of radiologists. Previous research presents conflicting evidence as to the impact of priming in scenarios where prevalence is naturally low, such as in screening mammography. Materials and Methods: An observer performance and eye position analysis study was performed. Four expert breast radiologists were asked to interpret two sets of 40 screening mammograms. The Control Set contained 36 normal and 4 malignant cases (located at case # 9, 14, 25 and 37). The Primed Set contained the same 34 normal and 4 malignant cases (in the same location) plus 2 “primer” malignant cases replacing 2 normal cases (located at positions #20 and 34). Primer cases were defined as lower difficulty cases containing salient malignant features inserted before cases of greater difficulty. Results: Wilcoxon Signed Rank Test indicated no significant differences in sensitivity or specificity between the two sets (P > 0.05). The fixation count in the malignant cases (#25, 37) in the Primed Set after viewing the primer cases (#20, 34) decreased significantly (Z = -2.330, P = 0.020). False-Negatives errors were mostly due to sampling in the Primed Set (75%) in contrast to in the Control Set (25%). Conclusion: The overall performance of radiologists is not affected by the inclusion of obvious cancer cases. However, changes in visual search behavior, as measured by eye-position recording, suggests visual disturbance by the inclusion of priming cases in screening mammography.

Rationale and Objectives: To identify parameters linked to higher levels of performance in screening mammography. In particular we explored whether experience in reading digital cases enhances radiologists’ performance. Methods: A total of 60 cases were presented to the readers, of which 20 contained cancers and 40 showed no abnormality. Each case comprised of four images and 129 breast readers participated in the study. Each reader was asked to identify and locate any malignancies using a 1-5 confidence scale. All images were displayed using 5MP monitors, supported by radiology workstations with full image manipulation capabilities. A jack-knife free-response receiver operating characteristic, figure of merit (JAFROC, FOM) methodology was employed to assess reader performance. Details were obtained from each reader regarding their experience, qualifications and breast reading activities. Spearman and Mann Whitney U techniques were used for statistical analysis. Results: Higher performance was positively related to numbers of years professionally qualified (r= 0.18; P Conclusion: This study suggests suggestion that readers with experience in digital images reporting may exhibit a reduced ability to correctly identify normal appearances requires further investigation. Higher performance is linked to number of cases read per year.