Agreement and precision of periprosthetic bone density measurements in micro-CT, single and dual energy CT.

The objective of this study was to test the precision and agreement between bone mineral density measurements performed in micro CT, single and dual energy computed tomography, to determine how the keV level influences density measurements and to assess the usefulness of quantitative dual energy computed tomography as a research tool for longitudinal studies aiming to measure bone loss adjacent to total hip replacements. Samples from 10 fresh-frozen porcine femoral heads were placed in a Perspex phantom and computed tomography was performed with two acquisition modes. Bone mineral density was calculated and compared with measurements derived from micro CT. Repeated scans and dual measurements were performed in order to measure between- and within-scan precision. Mean density difference between micro CT and single energy computed tomography was 72 mg HA/cm3 . For dual energy CT, the mean difference at 100 keV was 128 mg HA/cm3 while the mean difference at 110-140 keV ranged from -84 to -67 mg HA/cm3 compared with micro CT. Rescanning the samples resulted in a non-significant overall between-scan difference of 13 mg HA/cm3 . Bland-Altman limits of agreement were wide and intraclass correlation coefficients ranged from 0.29 to 0.72, while 95% confidence intervals covered almost the full possible range. Repeating the density measurements for within-scan precision resulted in ICCs >0.99 and narrow limits of agreement. Single and dual energy quantitative CT showed excellent within-scan precision, but poor between-scan precision. No significant density differences were found in dual energy quantitative CT at keV-levels above 110 keV. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1470-1477, 2017.

The influence of a continuing education program on the image interpretation accuracy of rural radiographers.

INTRODUCTION: In regional, rural and remote clinical practice, radiographers work closely with medical members of the acute care team in the interpretation of radiographic images, particularly when no radiologist is available. However, the misreading of radiographs by non-radiologist physicians has been shown to be the most common type of clinical error in the emergency department. Further, in Australia few rural radiographers are specifically trained to interpret and report on images. This study aimed to evaluate the accuracy of a group of rural radiographers in interpreting musculoskeletal plain radiographs, and to assess the effectiveness of continuing education (CE) in improving their accuracy within a short time frame. METHODS: Following ethics approval, 16 rural radiographers were recruited to the study. At inception a purpose-designed 'test-object' of 25 cases compiled by a radiologist was used to assess image interpretation accuracy. The cases were categorised into three grades of complexity. The radiographers entered their answers on a structured radiographer opinion form (ROF) that had three levels of response - 'general opinion', 'observations' and 'open comment'. Subsequent to base-line testing, the radiographers participated in a CE program aimed at improving their image interpretation skills. After a 4 month period they were re-tested using the same methodology. The ROFs were scored by the radiologist and the pooled results analysed for statistically significant changes at all ROF levels and grades of complexity. RESULTS: While for the small number of less complex grade 1 cases there was no change in image interpretation accuracy, for the more numerous and more complex grade 2 and grade 3 cases there was a statistically significant improvement at the 'general opinion' and 'observation' levels (paired t-test, p < 0.05). Also, with the exception of the small sample of grade 1 cases, the proportion of cases correctly interpreted by the radiographers decreased as the ROF level, and therefore the amount of detail required, increased. CONCLUSIONS: This study had a number of methodological limitations but the results suggest that short-term, intensive CE programs can improve the ability of radiographers to accurately interpret plain musculoskeletal radiographic examinations. Similar, larger scale initiatives such as this could help reduce the risk of misdiagnosis in acute care settings, especially in the absence of a radiologist. However, radiographers' ability to use radiological vocabulary needs improvement. The complementary role that exists between radiographers and other members of the acute care team should be nurtured and developed in the context of declining numbers of radiologists, particularly in non-metropolitan areas. Intensive, short-term training in image interpretation may target junior medical officers, GPs and critical care nurse practitioners, as well as radiographers.