Research On Computer-Aided 3D Frontal Sinus Human Identification For Chinese Han Population

ObjectiveAfter exhausting conventional individual identification technologies,such as DNA and fingerprint comparison,the comparison of ante-mortem(AM)imaging and post-mortem(PM)imaging data can be used as an effective supportive technology.Especially in recent years,the popularity of post-mortem image examination technology can provide available PM data.The anatomical uniqueness of the frontal sinus morphology has been widely used for comparative forensic identification using various techniques,mostly including 2D X-rays or one fixed slice of an axial Computed Tomography(CT)scan image.However,few studies have assessed the usefulness of a three-dimensional(3D)model of the frontal sinus for human identification.This paper aims to explore the ability of three-dimensional frontal sinus for forensic individual identification.Based on the intact three-dimensional model of the frontal sinus,the following studies are carried out: 1)develop standardized code system to classify the frontal sinus according to its 3D morphological metrics and discover the usefulness of the 3D frontal sinus model in identification of Chinese Han population;2)develop a computer-aided comparative paradigm based on the 3D-3D frontal sinus model superimposition process and further assesses the anatomical uniqueness of frontal sinuses using a large Chinese Han sample;3)The ellipse Fourier analysis is performed on the three-dimensional frontal sinus contour to calculate the similarity to evaluate the accuracy of individual identification of the frontal sinus.Methods1.One hundred and ninety-four computed tomography(CT)scans of patients older than 20 years(82 males and 110 females)were collected.A 3D frontal sinus digital model was segmented using Dolphin Imaging software.The following morphological metrics of the 3D frontal sinus were used to develop the coding system: bilateral or unilateral,spatial relationships of the two sides,number of septations,superior volume side,the shape of the 3D model of each side,shape of the medial surface and frontal ostium on each side,number of accessory septations on each side,number of supra-orbital cells of the medial surface and lateral surface on each side,and number of the arcades on each side.2.The study proposes use of a computer-aided comparative paradigm based on the 3D-3D frontal sinus model superimposition process and further assesses the anatomical uniqueness of frontal sinuses.Three hundred thirty-six patients older than20 years with two multi-slice CT scans were collected.Frontal sinus 3D models were semiautomatically segmented through Dolphin Imaging software.Automatic pairwise comparisons of 336 matched pairs from the same person and 336 mismatched pairs from different individuals with an analysis of average root mean square(RMS)point-to-point distance were performed using Geomagic Studio Qualify software.3.Extract 336 matched pairs and 336 mismatched pairs of frontal sinus outline which presented in in posterior view 2D images.The study applied the Shape software to do the Elliptical Fourier analysis,and explored the Fourier descriptor for the frontal sinus outline.Based on the Fourier descriptor we calculated the Correlation coefficient,Euclidean distance and Adjust the cosine distance for the matched pairs and mismatched pairs.Finally,the study explored the accuracy for the formal sinus human identification by calculating the AUC value based on the ROC.Results1.The new coding system accurately identified all of our research individuals.This study discovered a number of individual variations in the 3D frontal sinus morphology patterns.Most individuals(73.7%)had one complete middle septation.Twenty-three cases had another septation.The frontal sinus in 56.3% individuals had superiority of left area.size.The left sinus was bigger in volume for 45.1% of males and 60% of females.Most frequently,males(79.4%)and females(84.7%)had a fan-shaped left and right frontal sinus.Regarding the shape of the medial surface viewed laterally,the multi-surface of the left and right sinus in males was 73.4% and76.3%,respectively,while in females,it was 70.9% and 87%,respectively.The taper ostium was the most popular,55.5% in the total samples.The frontal sinus in35.7% of males and 28.7% of females had at least one accessory septation.The frontal sinus in 23% of males and 37.8% of females had at least one supra-orbital cells.Males most commonly had seven arcades(20.2%)two sides altogether.Arcades with six of two sides in females(18.5%)were most popular.2.RMSE ranged between 0.005 and 1.032(mean RMSE 0.390±0.25 mm)in the group of matches and between 1.107 and 19.363(mean RMSE 4.49±2.69 mm)in the group of mismatches.On average,the RMSE value was over ten-fold greater in mismatches than in matches.Statistically significant differences in RMSE between the group of matches and mismatches were assessed using the Mann-Whitney U test(p < 0.05).3.Fourier descriptor with the 10 harmonics can be used to descript the outline of the frontal sinus images.For the matched pairs the average Correlation coefficient is 0.99±0.009,the average Euclidean distance is 0.09856±0.059458;the average adjusted cosine distance is 0.1698±0.0829.For the mismatched pairs the average Correlation coefficient is 0.9416±0.0281,the average Euclidean distance is0.00317±0.041718;the average adjusted cosine distance is 0.4755±0.1222.And the accuracy based on the Correlation coefficient,Euclidean distance and Adjust the cosine distance was 98%,98% and 95%,respectively.ConclusionA coding system exposes the morphological variants of frontal sinuses and presents the usefulness of 3D frontal sinus model for human identification.This study supports the value of the frontal sinus with a 3D computer-aided superimposition method for human identification with large samples when DNA,fingerprints and dental materials are not accessible.