Chest radiographs versus CT for the detection of rib fractures in children (DRIFT): a diagnostic accuracy observational study

Abstract

SummaryBackgroundInternationally, chest radiography is the standard investigation for identifying rib fractures in suspected physical abuse in infants. Several small observation studies in children have found that chest CT can provide greater accuracy than radiography for fracture detection, potentially aiding medicolegal proceedings in abuse cases; however, to our knowledge, this greater accuracy has not been comprehensively evaluated. We aimed to determine differences in rib fracture detection rates between post-mortem chest radiographs and chest CT images, using forensic autopsy as the reference standard.MethodsIn this retrospective diagnostic accuracy study, we searched the Great Ormond Street Hospital (London, UK) radiology information system for all children aged 0–16 years who had a post-mortem skeletal survey (ie, full-body radiography), CT, and full autopsy between Jan 1, 2012, and Jan 1, 2017, for a purpose of death investigation. Cases were excluded if the imaging was done for a reason other than a forensic investigation or if image quality was suboptimal. Radiologists were recruited as reporters on a voluntary basis via membership databases from international radiology and post-mortem imaging societies with no specific inclusion or exclusion criteria. Reporters were sent a set of chest radiographs on a password protected and encrypted USB flash drive or via a secure filesharing website and independently reported on the presence of rib fractures, fracture location, and the confidence level of their interpretation. They were masked to the clinical information of the images. 1 month later, the same reporters were sent CTs for the same cases in a random order and asked to report on the same features. The primary objective was to compare the accuracy of detection of rib fractures by use of post-mortem chest radiographs and CTs, with autopsy data as reference standard. Accuracy was assessed by comparison of diagnostic statistics, calculated using random-intercept multilevel logistic models with reporter and patient included as cross-classified random-effects.Findings25 cases of children (aged 1 month to 7 years), with 136 rib fractures at autopsy with paired post-mortem chest radiographs and CTs, were selected for analysis. 38 radiologists were recruited as reporters from 23 international centres; 12 (32%) were consultants, median experience of 14·5 years (range 6–27), and 26 (68%) were registrars, median experience of 4 years (range 2–9). Across all radiologists, three times as many rib fractures were correctly detected by use of chest CTs compared with chest radiography (sensitivity 44·9% [95% CI 31·7–58·9] vs 13·5% [8·1–21·5]; difference 31·4% [23·3–37·8; p<0·001]). Sensitivity for detection on the correct rib was higher by use of CT than by use of radiography (62·4% [95% CI 44·9–77·1] vs 23·1% [12·9–37·8]; difference 39·3% [31·9–42·2; p<0·001]), as was diagnosis of a patient with any rib fracture or fractures (81·5% [75·8–86·0] vs 64·7% [57·3–71·4]; difference 16·7% [11·5–22·2; p<0·001]). Radiologist con...

The role of the forensic anthropologist in the pediatric autopsy: Interpretations, contributions, and challenges

“…Studies show that CT imaging is more sensitive than radiography for detecting rib fractures in pediatric cases (Gorincour et al, 2015; Hong et al, 2011; Shelmerdine et al, 2018; Wootton‐Gorges et al, 2008) and more sensitive than autopsy for detecting fractures in general (Krentz et al, 2016; Sieswerda‐Hoogendoorn, Soerdjbalie‐Maikoe, de Bakker, & van Rijn, 2014; van Wijk et al, 2017). Using the number and location of rib fractures identified at autopsy as the gold standard, Shelmerdine et al (2018) were able to correctly identify three times as many rib fractures using PMCT imaging than radiography and the accuracy was greater regardless of fracture location or the radiologists' experience. Similarly, Wootton‐Gorges et al (2008) and Hong et al (2011) reported that PMCT was more sensitive than radiography for detecting rib fractures.…”

Pediatric postmortem computed tomography: initial experience at a children’s hospital in the United States

“…2 and 3). CT has been shown to be more sensitive than radiographs for assessing rib fractures [19,47,48], although radiographs might be more sensitive for phalangeal fractures [19] and metaphyseal corner fractures (classic metaphyseal lesions); more study is needed comparing CT to radiography in this setting [13]. In the absence of signs of trauma, however, finding the cause of death is more challenging because expected postmortem changes and antemortem lung and brain pathology can have a similar appearance on postmortem CT [20,34,35,43,49].…”

“…Postmortem CT is superior to autopsy in detection of fractures [33], but evidence is limited that it is superior to radiographs in the setting of skeletal dysplasia [8,12,27]. Postmortem CT has been found to be better than radiography for rib fractures [47,48]; however CT has been found to be more limited in the setting of natural death [33,50,52]. But when no cause of death is found by autopsy, concordance with CT has been shown to be very good [34,51].…”

Broken bones and irresponsible testimony?

“…The idea that certain lesions are likely to represent abuse is widely believed but is based on circular reasoning (Berthold et al, 2018;Chauvin-Klimoff, Allard-Dansereau, & Colbourne, 2018;Flaherty et al, 2014;Högberg, Andersson, Högberg, & Thiblin, 2019;Paine, Fakeye, Christian, & Wood, 2019). Indeed, much current research is directed at maximizing the evidence of abuse (Raynor, Konala, & Freemont, 2018;Shelmerdine et al, 2018;Wood et al, 2018).…”