Early Detection of Fractures With Low-Dose Digital X-Ray Images in a Pediatric Trauma Unit

A comparison of computed tomography, X-ray and Lodox® scans in assessing pediatric skull fractures using piglets

Skull fractures are common in children both due to abuse and accidental incidences. The accurate detection of these fractures may therefore be critical. The aim of this study was to investigate the reliability of CT, X-ray, and Lodox^® scans, the latter which has not previously been evaluated and is commonly employed in South Africa, in detecting the number, location and type of pediatric skull fractures. Blunt force trauma was inflicted with a mallet on ten piglet skulls, which were CT, X-ray, and Lodox^® scanned and then macerated. The number, location, and type of skull fractures visible using each imaging modality, and on the cleaned skulls, were recorded. Sensitivities and specificities of each method were calculated. For fracture number and location, CTs had a sensitivity of 47.3%, X-rays 22.4% and Lodox^® 23.3%. For fracture type, sensitivities were 46.1%, 16.6%, and 17.8% for CT, X-ray, and Lodox^® , respectively. Specificities were high (92.5%-100%) which reduces the risk of incorrectly diagnosing fractures. However, low sensitivities increase the risk of failing to identify fractures and possible victims of abuse. Osteological analysis should preferably be the method of choice when evaluating pediatric skull trauma, and CTs should be used when osteological analysis is not feasible. If CT scanners are not available, X-rays and Lodox^® may have to be used. In these cases, additional radiographic views of the skull are imperative and may increase the sensitivity of these methods, although they are not recommended to detect exact pediatric skull fracture number, location, and type.

Filtration to reduce paediatric dose for a linear slot-scanning digital X-ray machine

This paper describes modelling, application and validation of a filtration technique for a linear slot-scanning digital X-ray system to reduce radiation dose to paediatric patients while preserving diagnostic image quality. A dose prediction model was implemented, which calculates patient entrance doses using variable input parameters. Effective dose is calculated using a Monte Carlo simulation. An added filter of 1.8-mm aluminium was predicted to lower the radiation dose significantly. An objective image quality study was conducted using detective quantum efficiency (DQE). The PTW Normi 4FLU test phantom was used for quantitative assessment, showing that image contrast and spatial resolution were maintained with the proposed filter. A paediatric cadaver full-body imaging trial assessed the diagnostic quality of the images and measured the dose reduction using a 1.8-mm aluminium filter. Assessment by radiologists indicated that diagnostic quality was maintained with the added filtration, despite a reduction in DQE. A new filtration technique for full-body paediatric scanning on the Lodox Statscan has been validated, reducing entrance dose for paediatric patients by 36 % on average and effective dose by 27 % on average, while maintaining image quality.

Fracture Detection in Traumatic Pelvic CT Images

Fracture detection in pelvic bones is vital for patient diagnostic decisions and treatment planning in traumatic pelvic injuries. Manual detection of bone fracture from computed tomography (CT) images is very challenging due to low resolution of the images and the complex pelvic structures. Automated fracture detection from segmented bones can significantly help physicians analyze pelvic CT images and detect the severity of injuries in a very short period. This paper presents an automated hierarchical algorithm for bone fracture detection in pelvic CT scans using adaptive windowing, boundary tracing, and wavelet transform while incorporating anatomical information. Fracture detection is performed on the basis of the results of prior pelvic bone segmentation via our registered active shape model (RASM). The results are promising and show that the method is capable of detecting fractures accurately.

Detection of chest trauma with whole-body low-dose linear slit digital radiography: a multireader study

OBJECTIVE

The objective of our study was to compare the performance of low-dose linear slit digital radiography (DR) with computed radiography (CR) for the detection of trauma sequelae in the chest including rib fractures, pneumothorax, and lung contusion.

MATERIALS AND METHODS

Eighty trauma victims (62 males, 18 females; mean age, 51.5 years) with a total of 612 rib fractures and 80 consecutive patients without rib fractures (59 males, 21 females; mean age, 39.5 years) were retrospectively analyzed. All patients had undergone whole-body linear slit DR and consecutive chest CT, and 87 patients underwent follow-up CR of the chest within 24 hours of DR and CT. Four blinded readers assessed image quality, rib fracture localization with diagnostic confidence, and the presence of pneumothorax and lung contusion on linear slit DR and CR images. Sensitivity for rib fractures and image quality were compared using the Wilcoxon's test. For the detection of pneumothorax and lung contusion, the difference in the areas under the receiver operating characteristic curves were calculated.

RESULTS

The rate of correctly identified rib fractures was higher (true-positive findings per image, 2.55 vs 2.21, respectively; p = 0.02), the rate of missed fractures was lower (false-negative findings per image, 4.98 vs 6.19; p = 0.02), and the diagnostic confidence was greater (2.03 vs 1.73 on a 3-point scale; p = 0.01) with linear slit DR than with CR, respectively. Image quality and performance for detecting pneumothorax and lung contusion with both techniques were not statistically different (p = 0.22, 0.85, and 0.55, respectively).

CONCLUSION

Linear slit DR is a reliable substitute for CR in the initial evaluation of chest trauma, with better sensitivity for detecting rib fractures and similar performance in assessing pneumothorax and lung contusion.

Personal experience with whole-body, low-dosage, digital X-ray scanning (LODOX-Statscan) in trauma

Background

Lodox-Statscan is a whole-body, skeletal and soft-tissue, low-dose X-ray scanner Anterior-posterior and lateral thoraco-abdominal studies are obtained in 3-5 minutes with only about one-third of the radiation required for conventional radiography. Since its approval by the Food and Drug Administration (FDA) in the USA, several trauma centers have incorporated this technology into their Advanced Trauma Life Support protocols. This review provides a brief overview of the system, and describes the authors' own experience with the system.

Methods

We performed a PubMed search to retrieve all references with 'Lodox' and 'Stat-scan' used as search terms. We furthermore used the google search engine to identify existing alternatives. To the best of our knowledge, this is the only FDA-approved device of its kind currently used in trauma.

Results and Conclusion

The intention of our review has been to sensitize the readership that such alternative devices exist. The key message is that low dosage full body radiography may be an alternative to conventional resuscitation room radiography which is usually a prelude to CT scanning (ATLS algorithm). The combination of both is radiation intensive and therefore we consider any reduction of radiation a success. But only the future will show whether LS will survive in the face of low-dose radiation CT scanners and magnetic resonance imaging devices that may eventually completely replace conventional radiography.