Three-dimensional printed models of the rib cage in children with non-accidental injury as an effective visual-aid tool

Value of chest CT over skeletal surveys in detection of rib fractures in pediatric patients

Recent literature has raised concerns about the sensitivity and accuracy of radiographs at diagnosing rib fractures. Studies have shown that chest computed tomography (CT) has far greater sensitivity at detecting rib fractures than radiographs. The purpose of this study was to evaluate the sensitivity of skeletal survey (SS) radiographs at diagnosis of rib fractures compared to CT in the pediatric population. This retrospective review included 57 patients who had undergone both a SS and a CT chest or CT chest/abdomen/pelvis within 30 days of each other for the indication of either non-accidental (NAT) or accidental trauma between 2009 and 2017. Images and reports were analyzed by a pediatric radiology fellow for presence/absence of fracture, evidence of healing and location of rib fracture, including rib level, location within the rib (anterior, lateral, and posterior), and side (right versus left). 225 rib fractures were identified in 25 patients on CT. 38 of those fractures were missed on the preceding SS, yielding a miss rate of 17%. Acute fractures were more likely to be missed than chronic or healing fractures (p ≤ 0.01). Location within the rib did not impact rib detection on radiographs. Left-sided rib fractures were not more common in NAT patients, compared to accidental trauma. SS miss approximately 17% of all rib fractures and CT is more sensitive modality in the detection of rib fractures, particularly acute rib fractures, regardless of location. Low-dose Chest CT could be a helpful modality in the work-up of NAT trauma.

Forensic 3D printing from micro-CT for court use- process validation

Forensic application of 3D scanning and printing technology is gaining momentum with 3D printed evidence starting to be produced for court. However, the processes for creating these forensic 3D models requires still rigorous assessment to ensure they adhere to the relevant legal standards. Although, previous work has examined the accuracy of 3D prints created from medical grade Computed Tomography (CT), no such assessment has been carried out for Micro Computed Tomography (micro-CT) which offers superior resolution and the ability to capture forensically relevant injuries. This study aimed to quantify the error rates associated with forensic 3D printed models and toolmarks, created using three different printing technologies, based on micro-CT data. Overall, 3D printed models, based on micro-CT scans, replicate bone surface geometry to sub-millimetre accuracy (<0.62mm for overall shape and <0.36mm for toolmarks). However, there were significant differences between the printing technology employed (mean errors of -0.3%, -0.8%, and 0.7% for shape geometry and -0.8%, 14.1%, and 0.7% for toolmark geometry for Printers 1-3 respectively). Where possible, the authors recommend micro-CT imaging for producing forensic 3D printed bone models particularly when injuries are present.

Temporal Pattern of Radiographic Findings of Costochondral Junction Rib Fractures on Serial Skeletal Surveys in Suspected Infant Abuse

BACKGROUND. Costochondral junction (CCJ) rib fractures pose a challenge in the radiographic detection and dating of infant abuse. OBJECTIVE. The purpose of this article was to assess the temporal pattern of radio-graphic findings of CCJ fractures on a serial skeletal survey (SS). METHODS. Reports of SSs performed for suspected infant abuse were reviewed to identify those reporting a CCJ fracture. Study inclusion required undergoing initial and approximately 2-week follow-up SSs that included anteroposterior and bilateral oblique radiographs of the reported CCJ rib fracture. Two pediatric radiologists retrospectively classified fractures in terms of the primary injury pattern (bucket-handle: visible crescentic fracture line; corner: visible triangular fracture line; other) and secondary healing pattern (growth disturbance; sclerosis; subperiosteal new bone formation [SPNBF]). Discrepant readings were resolved by consensus. RESULTS. The final cohort included 26 infants with 81 CCJ fractures. On initial SS, 59% (48/81) of fractures showed a primary pattern, most commonly a bucket-handle pattern (46%; 37/81); 6% (5/81) showed a primary pattern on follow-up SS (p < .001). On initial SS, the prevalence of a secondary pattern was 89% (72/81), most commonly a growth disturbance (85%; 69/81), followed by sclerosis (57%; 46/81); 80% (65/81) showed a secondary pattern on follow-up SS (p = .12). Overall prevalence of SPNBF was 28% (23/81). Addition of bilateral oblique views on initial SS resulted in a significant increase relative to the anteroposterior views alone in the detection of primary and secondary patterns by 15% (p = .04) and 30% (p < .001), respectively. CONCLUSION. A bucket-handle appearance is the most common primary pattern of fracture. The significantly lower prevalence of a primary pattern on follow-up vs initial SSs suggests that the CCJ fracture line is usually visible for only approximately 2 weeks. A growth disturbance of the rib end is the most common secondary pattern, followed by bony sclerosis, consistent with a healing injury. SPNBF is uncommon. Most CCJ fractures are in a healing phase at initial diagnosis. The signs of repair commonly remain visible on 2-week follow-up. The increased diagnostic yield of oblique views provides support to the inclusion of these projections in routine SS protocols. CLINICAL IMPACT. The findings will help radiologists improve the diagnosis and dating of CCJ rib fractures.

An Overview of 3D Printing in Forensic Science: The Tangible Third-Dimension

There has been a rapid development and utilization of three-dimensional (3D) printing technologies in engineering, health care, and dentistry. Like many technologies in overlapping disciplines, these techniques have proved to be useful and hence incorporated into the forensic sciences. Therefore, this paper describes how the potential of using 3D printing is being recognized within the various sub-disciplines of forensic science and suggests areas for future applications. For instance, the application can create a permanent record of an object or scene that can be used as demonstrative evidence, preserving the integrity of the actual object or scene. Likewise, 3D printing can help with the visualization of evidential spatial relationships within a scene and increase the understanding of complex terminology within a courtroom. However, while the application of 3D printing to forensic science is beneficial, currently there is limited research demonstrated in the literature and a lack of reporting skewing the visibility of the applications. Therefore, this article highlights the need to create good practice for 3D printing across the forensic science process, the need to develop accurate and admissible 3D printed models while exploring the techniques, accuracy and bias within the courtroom, and calls for the alignment of future research and agendas perhaps in the form of a specialist working group.