ABSTRACT
The three-dimensional visualization model of human body duct is based on virtual anatomical structure reconstruction with duct angiography,which realizes virtual model transferred from two-dimensional,planar and static images into three-dimensional,stereoscopic and dynamic ones repectively.In recent years,the multi-duct segmentation and division of the same specimen (or organ) is the focus of attention shared by surgeons and clinical anatomists.On the basis of 4.22 g/cm3 body bone density,this study has screened out metal oxide contract agent with different density for infusion and modeling,as well as compared and analyzed the effects of three-dimensional image of CT virtual bronchoscopy (CTVB),three-dimensional image of CT maximum intensity projection and three-dimensional model.This experiment result showed synchronously infusing multi-duct of same specimen (or organ) with contrast agent in different densities could reconstruct three-dimensional models of all ducts once only and adjust threshold to develop single or multiple ducts.It was easier to segment and observe the duct structure,anastomosis,directions and crossing in different parts,which was beyond comparison with three-dimensional image of CTVB.Although the existing three-dimensional duct reconstruction techniques still cannot be applied in living bodies temporarily,this study focused on a creative design of ducts segmentation in different density,which proposed a new experimental idea for developing multi-duct three-dimensional model in living body in the future.It will play a significant role in disease diagnosis and individual design in surgical treatment program.Therefore,this study observes the three-dimensional status of human duct with the application of contrast agent fillers in different density,combined with three-dimensional reconstruction technology.It provides an innovative idea and method for constructing three-dimensional model of digital multi-duct specimen,and the ultimate goal is to develop the digitized virtual human and precise medical treatment better and faster.
ABSTRACT
objective To observe the distribution of vitamin D receptor(VDR)gene polymorphisms in children of Han nationality and investigate the relationship between VDR gene polymorphisms and the susceptibility to children's dental fluorosis of Han nationality.Methods From October of 2008 to March of 2009,a case-control study was conducted among children between 8 and 12 years old with(n=101)and without(n=102)dental fluorosis using Dean method in Guandian countyside of Fengtai county in Anhui province.DNA was extracted from blood samples ofthese children.The Apa I,Bsm I,Fok I and raq I polymorphisms in the VDR gene were genotyped using polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP).The distribution of the genotypes in patients and the control group were analyzed. Results Different genotypes of the VDR gene existed in children of Han nationality with the highest distribution frequency of Aa, bb, Ff, TT, which respectively was 51.7% ( 105/203 ), 89.7% (182/203), 52.7% (107/203), 93.1% (189/203), followed by genotype distribution frequency of aa, Bb, FF, Tt, being 39.9% (81/203),7.9% (16/203),31.5% (64/203) ,6.9% (14/203), respectively. AA,BB, ff, tt distribution frequency was the lowest as follows, 8.4% ( 17/203 ), 2.4% (5/203), 15.8% (32/203),0 (0/203). The frequency distribution of VDR Apa I genotype was AA 7.9% (8/101), Aa 55.4% (56/101), aa 36.7%(37/101) in children with fluorosis, and AA 8.8% (9/102), Aa 48.0% (49/102), aa 43.3% (44/102) in children without fluorosis, respectively. There were no significant differences in the two groups(χ2= 1.13, P > 0.05).The frequency distribution of VDR Bsm I genotype was BB 3.0%(3/101), Bb 5.9%(6/101 ), bb 91.1% (92/101) in children with fluorosis, and BB 2.0% (2/102), Bb 9.8% (10/102), bb 88.2% (90/102) in children without fluorosis, respectively. There were no significant differences in the two groups(χ2 = 0.55, P > 0.05). The frequency distribution of VDR Fok I genotype was FF 28.7%(29/101), Ff 56.4% (57/101), ff 14.9%(15/101) in children with fluorosis, and FF 34.3% (35/102), Ff 49.0% (50/102), ff 16.7% (17/102) in children without fluorosis,respectively. There were no significant differences in the two groups(χ2 = 1.14, P > 0.05). The frequency distribution of VDR Taq I genotype was TT 93.1%(94/101), Tt 6.9%(7/101) in children with fluorosis, and TT 93.1% (95/102), Tt 6.9%(7/102) in children without fluorosis, respectively. The tt genotype was not found. There were no significant differences in the two groups (χ2 = 0.00, P > 0.05 ). Conclusions Different genotypes of the VDR gene existed in children of Han nationality. There were no correlation between VDR Apa I , Bsm I , Fok I , Taq I gene polymorphisms and children's dental fluorosis of Han nationality in this area.