Background The document “European Guidelines on Quality Criteria for Diagnostic Radiographic Images” describes the visualisation of anatomical criteria to which a radiograph of diagnostic quality should comply. This research investigates the correlation between the evaluation of anatomical structures, presented in the European guidelines, and the classification of radiographs for diagnostic acceptability. Methods Sixteen radiographers classified 22 chest radiographs in terms of diagnostic acceptability using the RadLex categories, and scored the representation of five anatomical criteria on a scale from 1 to 5. All radiographs were visualised with ViewDex on a DICOM calibrated display. Observers were recruited in Belgium and Ireland. An interclass correlation coefficient was applied to evaluate internal consistency for each observer group. A Mann–Whitney U-test was applied to investigate differences in classification between countries. The relationship with the evaluation of anatomical structures was investigated with ordinal logistic regression. Results Both groups of observers performed with acceptable consistency. The Mann–Whitney U test illustrated a significant difference in classification between the two countries. The ordinal logistic regression indicated for each country a weak correlation between the RadLex and the anatomical structures. Certain factors in the radiograph, possibly others than anatomical elements, must be significantly better before the observer will attribute a higher RadLex score. Conclusion The relationship between the evaluation of anatomical criteria and the diagnostic acceptability is weak for both countries. When assigning a radiograph to a certain category of acceptability, other factors influence the decision.
Introduction: Radiographers evaluate anatomical structures to judge clinical acceptability of a radiograph. Whether a radiograph is deemed acceptable for diagnosis or not depends on the individual decision of the radiographer. Individual decisions cause variation in the accepted image quality. To minimise these variations definitions of acceptability, such as in RadLex, were developed. On which criteria radiographers attribute a RadLex categories to radiographs is unknown. Insight into these criteria helps to further optimise definitions and reduce variability in acceptance between radiographers. Therefore, this work aims the evaluation of the correlation between the RadLex classification and the evaluation of anatomical structures, using a Visual Grading Analysis (VGA) Methods: Four radiographers evaluated the visibility of five anatomical structures of 25 lateral cervical spine radiographs on a secondary class display with a VGA. They judged clinical acceptability of each radiograph using RadLex. Relations between VGAS and RadLex category were analysed with Kendall’s Tau correlation and Nagelkerke pseudo-R². Results: The overall VGA score (VGAS) and the RadLex score correlate (rτ= 0.62, p<0.01, R2=0.72) strongly. The observers’ evaluation of contrast between bone, air (trachea) and soft tissue has low value in predicting (rτ=0.55, p<0.01, R2=0.03) the RadLex score. The reproduction of spinous processes (rτ=0.67, p<0.01, R2=0.31) and the evaluation of the exposure (rτ=0.65, p<0.01, R2=0.56) have a strong correlation with high predictive value for the RadLex score. Conclusion: RadLex scores and VGAS correlate positively, strongly and significantly. The predictive value of bony structures may support the use of these in the judgement of clinical acceptability. Considerable inter-observer variations in the VGAS within a certain RadLex category, suggest that observers use of observer specific cut-off values.
Several studies have demonstrated the importance of environmental conditions in the radiology reporting environment, with many indicating that incorrect parameters could lead to error and misinterpretation. Literature is available with recommendations as to the levels that should be achieved in clinical practice, but evidence of adherence to these guidelines in radiology reporting environments is absent. This study audited the reporting environments of four teleradiologist and eight hospital based radiology reporting areas. This audit aimed to quantify adherence to guidelines and identify differences in the locations with respect to layout and design, monitor distance and angle as well as the ambient factors of the reporting environments. In line with international recommendations, an audit tool was designed to enquire in relation to the layout and design of reporting environments, monitor angle and distances used by radiologists when reporting, as well as the ambient factors such as noise, light and temperature. The review of conditions were carried out by the same independent auditor for consistency. The results obtained were compared against international standards and current research. Each radiology environment was given an overall compliance score to establish whether or not their environments were in line with recommended guidelines. Poor compliance to international recommendations and standards among radiology reporting environments was identified. Teleradiology reporting environments demonstrated greater compliance than hospital environments. The findings of this study identified a need for greater awareness of environmental and perceptual issues in the clinical setting. Further work involving a larger number of clinical centres is recommended.
A number of different viewing distances are recommended by international agencies, however none with specific reference to radiologist performance. The purpose of this study was to ascertain the extent to which radiologists performance is affected by viewing distance on softcopy skeletal reporting. Eighty dorsi-palmar (DP) wrist radiographs, of which half feature 1 or more fractures, were viewed by seven observers at 2 viewing distances, 30cm and 70cm. Observers rated the images as normal or not on a scale of 1 to 5 and could mark multiple locations on the images when they visualised a fracture. Viewing distance was measured from the centre of the face plate to the outer canthus of the eye. The DBM MRM analysis showed no statistically significant differences between the area under the curve for the two distances (p = 0.482). The JAFROC analysis, however, demonstrated a statistically significantly higher area under the curve with the 30cm viewing distance than with the 70 cm distance (p = 0.035). This suggests that while observers were able to make decisions about whether an image contained a fracture or not equally well at both viewing distances, they may have been less reliable in terms of fracture localisation or detection of multiple fractures. The impact of viewing distance warrants further attention from both clinical and scientific perspectives.
In February 2011 the University of Chicago Medical School distributed iPads to its trainee doctors for use when
reviewing clinical information and images on the ward or clinics. The use of tablet computing devices is becoming
widespread in medicine with Apple™ heralding them as "revolutionary" in medicine. The question arises, just because
it is technical achievable to use iPads for clinical evaluation of images, should we do so? The current work assesses the
diagnostic efficacy of iPads when compared with LCD secondary display monitors for identifying lung nodules on chest
x-rays.
Eight examining radiologists of the American Board of Radiology were involved in the assessment, reading chest images
on both the iPad and the an off-the-shelf LCD monitor. Thirty chest images were shown to each observer, of which 15
had one or more lung nodules. Radiologists were asked to locate the nodules and score how confident they were with
their decision on a scale of 1-5. An ROC and JAFROC analysis was performed and modalities were compared using
DBM MRMC.
The results demonstrate no significant differences in performance between the iPad and the LCD for the ROC AUC
(p<0.075) or JAFROC FOM (p<0.059) for random readers and random cases. Sample size estimation showed that this
result is significant at a power of 0.8 and an effect size of 0.05 for ROC and 0.07 for JAFROC.
This work demonstrates that for the task of identifying pulmonary nodules, the use of the iPad does not significantly
change performance compared to an off-the-shelf LCD.
The hazards associated with ionizing radiation have been documented in the literature and therefore justifying the need
for X-ray examinations has come to the forefront of the radiation safety debate in recent years1. International legislation
states that the referrer is responsible for the provision of sufficient clinical information to enable the justification of the
medical exposure. Clinical indications are a set of systematically developed statements to assist in accurate diagnosis and
appropriate patient management2. In this study, the impact of clinical indications upon fracture detection for
musculoskeletal radiographs is analyzed. A group of radiographers (n=6) interpreted musculoskeletal radiology cases
(n=33) with and without clinical indications. Radiographic images were selected to represent common trauma
presentations of extremities and pelvis. Detection of the fracture was measured using ROC methodology. An eyetracking
device was employed to record radiographers search behavior by analysing distinct fixation points and search
patterns, resulting in a greater level of insight and understanding into the influence of clinical indications on observers'
interpretation of radiographs. The influence of clinical information on fracture detection and search patterns was
assessed. Findings of this study demonstrate that the inclusion of clinical indications result in impressionable search
behavior. Differences in eye tracking parameters were also noted. This study also attempts to uncover fundamental
observer search strategies and behavior with and without clinical indications, thus providing a greater understanding and
insight into the image interpretation process. Results of this study suggest that availability of adequate clinical data
should be emphasized for interpreting trauma radiographs.
Digital radiography poses the risk of unnoticed increases in patient dose. Manufacturers responded to this by offering
an exposure index (EI) value to clinicians. Use of the EI value in clinical practice is encouraged by the American
College of Radiology and American Association of Physicists in Medicine. This study assesses the impact of
processing delay on the EI value. An anthropormorphic phantom was used to simulate three radiographic examinations;
skull, pelvis and chest. For each examination, the phantom was placed in the optimal position and exposures were
chosen in accordance with international guidelines. A Carestream (previously Kodak) computed radiography system
was used. The imaging plate was exposed, and processing was delayed in various increments from 30 seconds to 24
hours, representing common delays in clinical practice. The EI value was recorded for each exposure. The EI value
decreased considerably with increasing processing delay. The EI value decreased by 100 within 25 minutes delay for
the chest, and 20 minutes for the skull and pelvis. Within 1 hour, the EI value had fallen by 180, 160 and 100 for the
chest, skull and pelvis respectively. After 24 hours, the value had decreased by 370, 350 and 340 for the chest, skull
and pelvis respectively, representing to the clinician more then a halving of exposure to the detector in Carestream systems. The assessment of images using EI values should be approached with caution in clinical practice when delays in processing occur. The use of EI values as a feedback mechanism is questioned.
Introduction
The American Association of Medical Physicists is currently standardizing the exposure index (EI) value. Recent studies
have questioned whether the EI value offered by manufacturers is optimal. This current work establishes optimum EIs
for the antero-posterior (AP) projections of a pelvis and knee on a Carestream Health (Kodak) CR system and compares
these with manufacturers recommended EI values from a patient dose and image quality perspective.
Methodology
Human cadavers were used to produce images of clinically relevant standards. Several exposures were taken to achieve
various EI values and corresponding entrance surface doses (ESD) were measured using thermoluminescent dosimeters.
Image quality was assessed by 5 experienced clinicians using anatomical criteria judged against a reference image.
Visualization of image specific common abnormalities was also analyzed to establish diagnostic efficacy.
Results
A rise in ESD for both examinations, consistent with increasing EI was shown. Anatomic image quality was deemed to
be acceptable at an EI of 1560 for the AP pelvis and 1590 for the AP knee. From manufacturers recommended values, a
significant reduction in ESD (p=0.02) of 38% and 33% for the pelvis and knee respectively was noted. Initial
pathological analysis suggests that diagnostic efficacy at lower EI values may be projection-specific.
Conclusion
The data in this study emphasize the need for clinical centres to consider establishing their own EI guidelines, and not
necessarily relying on manufacturers recommendations. Normal and abnormal images must be used in this process.
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