CT rendering and mechanical analysis for rib fracture inextricable on X-ray chest film in legal medical practice / 法医学杂志

OBJECTIVE@#To explore an approach of CT rendering and mechanical analysis for rib fracture that was inextricable on X-ray film in legal medical practice.@*METHODS@#17 cases with rib fracture undetermined on X-ray chest film in legal medical practice underwent CT scans. The thin slices (0.75 mm or lmm) of images were reconstructed with smooth and sharp kernel. The multiplanar reformatted images along rib and surface shaded display were obtained to investigate rib fracture.@*RESULTS@#All rib fractures were accurately displayed by CT scan and MPR images along rib. The torque that caused rib fracture was divided presumably into vertical and rotary types. The two kinds of rib fracture, composed of vertical and rotary type, were proposed.@*CONCLUSION@#CT scan with thin slice and MPR images can definitely reveal the rib fracture unresolved on X-ray film in legal medical practice. The proposition of two kinds of torque will be help avoid misunderstanding acute rotary type of rib fracture as old healed one.

Anatermic separated epiphysis or avulsion fracture: image observation / 法医学杂志

OBJECTIVE@#To explore an approach to distinguish avulsion fracture of articular portion from anatomic separated epiphysis.@*METHODS@#21 cases with suspicioned avulsion fracture of articular portion of tubular bone were reviewed. The cortical continuity of separate small bone and contiguous bone portion was investigated. The swell of soft tissue around these small bones was observed simultaneously. Then the configuration of the fracture was researched by injury mechanics.@*RESULTS@#Continued bone cortex between separate small bone and corresponding bone was seen in 15 cases, so they were considered as a separate epiphysis. Sharp linear fracture between the separate small bone and corresponding bone were seen in 6 cases. The swell of soft tissue around the separate small bone was observed in all cases, so they were considered as a avulsion fracture.@*CONCLUSION@#The meticulous investigation of separated small bone at the articular portion by image observation is of important value for distinguishing avulsion fracture from anatomic separate epiphysis.

Inferior orbital fissure and groove: axial CT findings and their anatomic variation / 法医学杂志

OBJECTIVE@#To show imaging findings of inferior orbital fissure (IOF) and groove (IOG) on axial CT scans and to discover their anatomic variations, so as to avoid misdiagnosing them as orbital fracture.@*METHODS@#25 normal skull were used to investigate the configurations of IOF and IOG. Five skulls were performed axial CT scans. 20 normal orbital axial scans were studied as well. MPR and RT-3D reconstructions were used in this study.@*RESULTS@#Skulls scans and normal orbital images on axial CT showed three sorts of findings: (1) single bony dehiscence between lateral and inferior walls; (2) first type of double bony dehiscence between lateral and inferior walls, among the dehiscence interposing a small bone. The long axis of the small bone was parallel to orbital wall; (3) second type of double bony dehiscence between lateral and inferior walls, but the long axis of the small bone was in anteroposterior direction. Anatomy and variation of three sorts of CT findings were corresponded respectively to: (1) a baseball club-shaped IOF; (2) a "V"-shaped IOF, that is composed of both of lateral and internal ramus, lateral ramus situates between the zygoma and the lateral portion of greater wing of sphenoid, and internal ramus between the maxilla and the internal portion of greater wing of sphenoid, both rami intercross caudally and open upwards in a "V"-shaped configuration; (3) a deep IOG with a protuberant lateral wall.@*CONCLUSION@#Familiarity of imaging features on the axial CT scans and understanding of their anatomy of IOF and IOG would be helpful for avoiding misdiagnosis of orbital fracture.

Prospective study of lethal blood concentration of organophosphorous in humans / 法医学杂志

Total cases of organophosphorous (dichlorvos, methamidophos, dimethoate) poisoning outpatients from six hospitals during four years were collected consecutively for lethal blood concentration study. Blood samples were detected with gas chromatography. The probabilities of death, coma were analyzed with Bliss method and their linear regressive equations of probit were obtained respectively, their 50% lethal concentrations (LC50) and 50% coma concentrations(CC50) were calculated by the formulas above. As the death rate was influenced by therapy, its natural death probability has been discussed and estimated their natural LC50 were between the LC50 and CC50 themselves. Combined LC50 and CC50, their natural LC50 were calculated.