Int J Leg Med (1994) 107:90-95 © Springer-Verlag 1994 Anthony Busuttil • Jason J. Hanley A semi-automated micro-method for the histological assessment of fat embolism Received: 14 March 1994 / Received in revised form: 10 June 1994 Abstract A method of quantitatively determining the volume of fat emboli in a tissue using an image analysis system (I.B.A.S.) was developed. This procedure is an in- teractive, semi-automated tool allowing the quick and ac- curate gathering of large quantities of data from sections of different tissue samples stained by osmium tetroxide. The development of this procedure was aimed at produc- ing a system which is reliable, reproducible and semi-au- tomated thereby enabling epidemiological and serial stud- ies to be made of a large number of histological sections from different tissues. The system was tested in a study of tissue sections from a series of fatalities from an aircraft crash in an attempt at correlating the incidence of fat em- boli with the presence of multiple fractures and soft tissue injuries, the correlation to be made being between the quantitative presence of fat emboli and the extent and severity of injuries suffered. Key words Fat embolism • Image-analysis, I.B.A.S. Osmium tetroxide Zusammenfassung Mit Hilfe eines interaktiven Bild- analysen-Systems (I.B.A.S.) wurde eine Methode fiir die quantitative Bestimmung des Volumens von Fettemboli im Gewebe entwickelt. Es handelt sich um ein halbauto- matisches Verfahren, das die rasche und genaue Auswer- tung zahlreicher Daten an Schnitten yon mit Osmiumte- troxid behandelten Gewebsproben erlaubt. Das halbauto- matische System arbeitet zuverl~issig und liefert reprodu- zierbare Ergebnisse. Es erm6glicht epidemiologische Stu- dien und Serienuntersuchungen an einer groBen Anzahl histologischer Schnitte yon verschiedenen Geweben. Die A. Busuttil ( ~ ) Forensic Medicine Unit, Department of Pathology, University of Edinburgh, Medical School, Teviot Place, Edinburgh EH8 9AG, UK J. J. Hanley Department of Biology and Preclinical Medicine, Bute Medical Building, St. Andrews University, St. Andrews, Fife KY16 9TS, UK Testung des Systems erfolgte an Gewebsschnitten von Or- ganen der Opfer eines Flugzeugabsturzes, wobei die Kor- relation zwischen Ausmag der Fettembolie und Schwere der erlittenen Verletzungen tiberprtift wurde. SchliisselwSrter Fettembolie • interaktives Bildanalysen-System, I.B.A.S. • Osmiumtetroxid Introduction The vast improvement in the survival of severely and multiply injured patients has once more focused medical awareness on the contribution of the 'fat embolism syn- drome' to both early and delayed post-trauma mortality (Schien & Saadia 1990). It has been suggested that al- though in most traumatised patients fat emboli do occur, particularly when there is a combination of extensive soft tissue injury coupled with long bone and pelvic fractures (Weisz & Steiner 1971), it is the number and size of such emboli that are of major importance: the more abundant the number of such emboli and the bigger their size, the more severe is their expected impact on the patient's po- tential for survival (Goris & Draaisma 1982). The clinical importance of fat emboli was highlighted even further with the recently increasing trend of active orthopaedic intervention as part of the emergency treatment of trauma patients (Meek et al. 1981). Treatment protocols nowa- days emphasise the requirement for an early internal fixa- tion of unstable long bone fractures with the further po- tential for fat embolisation intra-operatively, but the theo- retical prevention of delayed fatal embolisation (Riska et al. 1976). To assess objectively any of these hypotheses and to alter surgical intervention regimes appropriately and soundly, it would be useful to be able to assess accurately the degree and spread of fat emboli in patients who have succumbed to their injuries and to relate these to the time elapsed after their infliction, and to the type of injuries sustained. Such an assessment by light microscopy is a painstakingly laborious process, fraught with observer er-