Chris O’Donnell

“Buckle” rib fracture: An artifact following cardio-pulmonary resuscitation detected on postmortem CT

Buckle rib fractures are incomplete fractures involving the inner cortex alone, and are rarely detected on routine chest X-ray or at autopsy. The characteristics of these fractures have not been well evaluated in situ although they are commonly observed on postmortem CT images especially following CPR. The postmortem CT findings in 42 cases showing buckle rib fractures caused by CPR were reviewed. The cause of death in all cases was non-traumatic. The shape, number, location, and distribution of these buckle rib fractures and their relationship to other types of rib fractures were evaluated using a novel oblique axial multiplanar reconstruction technique. Almost all incomplete rib fractures associated with CPR are buckle rib fractures (90.5%). All rib fractures were distributed from the second to ninth ribs with over 95% being within the second to seventh ribs. Buckle rib fractures are dominant in the seventh to ninth ribs and the proportion of buckle rib fractures located in the vicinity of the costochondral junctions increases with the lower ribs. Over 97% of all CPR associated rib fractures are located in the anterior one third of the ribs based on a new measurement method utilizing oblique axial multiplanar reconstruction of the CT data. When recognition of incomplete or buckle rib fractures on postmortem CT is taken into account, detection of symmetry and continuity of rib fractures typically associated with CPR is improved compared with the detection of complete fractures alone. Recognition of buckle rib fractures and their characteristics on postmortem CT is of benefit to the forensic pathologist in evaluating the possibility of CPR and the differentiation of resuscitative artifact from forensically significant visceral injury observed at autopsy.

Non-invasive visualisation and volume estimation of maggot masses using computed tomography scanning

There is limited understanding of the actual temperatures that maggots experience during growth. The impact of maggot mass heating on their growth rates cannot be properly factored into maggot growth rate models, thus limiting the accuracy of forensic entomology estimates. One of the major factors contributing to mass heating is the mass size; however, measuring mass volume is problematic as masses quickly become disturbed when probing them to measure their depth and width. Furthermore, many masses are deep within the body cavity and are inaccessible. This study examined the development of a non-invasive means for measuring mass volume using computed tomography (CT) scanning. It was found that CT can be used to visualise and measure the volume of maggot masses, and a series of rules for doing so were established. The level of agreement between mass measurements made by four ‘judges’ using CT volumetric analysis tools produced excellent reliability (ICC > 0.95). This high level of reliability was maintained when applied to masses of different sizes in experimental cups of meat and natural masses of mixed species on human bodies. Entomological features of mortuary CT scans are now routinely reported in forensic entomology casework in Victoria, Australia, as a result of our work.

Lethal hemorrhage from a ureteric–arterial–enteric fistula diagnosed by postmortem CT angiography

Fistula formation following pelvic surgery and radiotherapy, including ureteric–arterial fistulas (UAF), is well documented, however, ureteric–arterial–enteric fistula is extremely rare. Conventional autopsy is usually required for the definitive diagnosis of pelvic vascular fistulas although an accurate diagnosis can still be complicated and challenging. The role of post-mortem computed tomography (PMCT) as an adjunct to conventional autopsy is well documented in the literature. One of the limitations of PMCT is the diagnosis of vascular conditions. Post-mortem computed tomography angiography (PMCTA) is a recently introduced technique that can assist in detecting such pathology. We present a case of post-radiotherapy ureteric–arterial–enteric fistula presenting as massive rectal and vaginal bleeding diagnosed prior to autopsy on PMCTA. The role of PMCTA in the diagnosis of such a UAF has not previously been reported in the literature.

Post-mortem CT findings in a case of necrotizing cellulitis of the floor of the mouth (Ludwig angina)

Ludwig angina is a rare but potentially lethal infection of the submandibular space that can cause significant upper airway obstruction. We report a case of undiagnosed Ludwig angina that progressed rapidly to death. Ludwig angina was suspected after post-mortem computed tomography (PMCT) found swollen mylohyoid muscle with stranding in subcutaneous fat, thickening of deep fascia, and local lymphadenopathy. Subsequently, an autopsy revealed woody induration of the submental region and liquefactive necrosis of the mylohyoid muscle, confirming the diagnosis. It is likely that the dental abscess identified on PMCT was the source of infection. Multiple invasive medical procedures were performed on the subject by the ambulance crew prior to his death. PMCT assisted further in determining procedural success.

Sudden cardiac death from aortoesophageal fistula: an autopsy case report of a rare complication of thoracic aortic aneurysm

This case of sudden cardiac death was referred to the coroner for investigation. An 80 year old man was attended by paramedics after experiencing a seizure and hematemesis. Cardiopulmonary resuscitation was unsuccessfully attempted and death was declared. A review of the patient’s past medical notes showed an ante mortem chest x-ray had an incidental finding of gross mediastinal widening and hilar enlargement. The patient elected not to have a follow up computerized tomography (CT).