Correlation Of Computed Tomography Scan Findings With Autopsy Findings In Fatal Head Injury Cases- A One And Half Year Hospital Based Cross Sectional Study

Abstract

The injury to the head is one of the most common and important aspect in Forensic practice as it accommodates most important vital organ of human body- The Brain, Master of all organs. It has become a significant public health problem and is predicted to surpass many diseases and become a major cause of death and disability by 2020. The motor vehicle accidents are the leading cause of head injury followed by falls, physical assaults, firearm wounds and others. Since the head contains brain, the most important vital organ, trauma to this region challenges the individual because of its anatomical position, size and movements in all directions. Despite improvements in safety measures in vehicles and greater availability of emergency measures, head injuries have not declined. Some of the factors that increase the risk of road traffic accidents in India are lack of people following the traffic rules, drunk driving, rash driving, poor conditions of the road, encroachment that restricts safe areas for pedestrian and young adults trying numerous stunts on the roads. MATERIALS AND METHODS A hospital based cross sectional study of all fatal head injury cases subjected for medicolegal autopsy to the Department of Forensic Medicine and Toxicology, Jawaharlal Nehru Medical College, Belagavi with definite history of trauma where prior CT scan head was taken during the hospitalization from January 2017 to July 2018. Further a comparative evaluation of postmortem findings of the head injuries with that of the CT scan were analyzed by using SPSS software version 25 and the results were calculated in percentages. Informed expressed consent was taken and a pre-tested proforma specially designed for this purpose was used for collecting the information. RESULTS Out of 172 cases of head injury 70 cases were hospitalized, CT scan of head was done and were subjected to postmortem examination and hence these 70 cases are included in this study. The most vulnerable age group for head injury was 19-29 years. 56 (80%) were males as compared to 14 (20%) females. The most common cause of acute head trauma came out to be road traffic accidents (90%) followed by fall from height (10%). 40 cases (57.2%) were from rural background whereas 30 cases (42.8%) were from urban background. Among 63 cases of road traffic accidents, 37 cases (52.9%) were 2-wheeler riders followed by 14 cases (20%) of pillion riders while 11 (15.7%) were pedestrians. In more than half of the cases (57.2%) the head injury was suspected and CT scan was done within 4 hours of the suspected trauma to the head. In 30 cases (42.8%) survival period was 1-7 days while in 7 cases (10%) the survival period was more than a week. In 17 cases (24.3%) the patient died in less than 12 hours after doing a CT scan while in 29 cases (41.4%) they died in 2-7 days. Out of 70 cases, scalp injury was observed in 64 cases in postmortem examination but CT scan could pick scalp injury in only 31 cases so there is incongruence of 33 cases in scalp injury. Among 70 cases, skull fractures were reported in 47 cases at autopsy while CT scan could detect only 36 cases so there was disparity of 11 cases in skull fractures. 6 cases (54.5%) of exclusive basal fractures were missed alongwith 5 cases (45.5%) involving both base and vault by CT scan. The most common type of skull fractures missed by CT scan were solitary fissured fractures (5 cases) followed by 2 cases of comminuted fractures and a case of depressed fracture. 8 cases of fracture of the petrous part of temporal bone were missed alongwith 6 cases of squamous temporal bone and 3 cases of frontal bone. Anterior cranial fossa, Middle cranial fossa and Posterior cranial fossa fractures were missed in 3 cases each in CT scan as compared to Autopsy. Among the intracranial hemorrhages, subarachnoid hemorrhage was undetected in 22 cases, subdural hemorrhage was undetected in 11 cases, and extradural hemorrhage was undetected in 1 case while intracerebral hemorrhage was undetected in 3 cases. Contusions were missed in 11 cases (26.8%) by CT scan. CONCLUSION Autopsy being a direct visual examination of the lesions can detect more pathological findings compared to CT scan which is a virtual interpretation of intracranial lesions. CT scans are inadequate for courtroom testimony but they provide great help to the clinicians in the emergency conditions. If the evidence of trauma is based solely on CT scan reports, there is a high possibility of erroneous accusations and convictions.