The Application Of Three-dimensional Reconstruction And 3D Printing In The Diagnosis And Treatment Of Tetralogy Of Fallot

BackgroundIn the early,three dimensional reconstruction and 3D printing is mainly applied in the development of new products and mass production of some simple materials.Its application in the medical field can be derived from the 1990 s when researchers used CT to produce the model that shows a complete skull internal anatomical.This represents the beginning of the era of medical 3D printing.And then with the development of economy and the constant innovation of science and technology,three dimensional reconstruction and 3D printing was further applied in medical apparatus and instruments,medical organs in vitro model and the replacement of human organs.The clinical application of 3D model was well received by medical workers because of the great help.ObjectiveThe pathological model of tetralogy of fallot(TOF)with equal proportion was printed ccording to the preoperative CT data.To explore the value of three dimensional reconstruction and 3D printing in the diagnosis and treatment of TOF,Which provides a new perspective for the clinical diagnosis and treatment of TOF.MethodsTwenty patients with TOF diagnosed by echocardiography admitted to the Seventh People's Hospital of Zhengzhou City from January 2016 to July 2017 were selected,including 12 males and 8 females,aged from 1year and 2 months to 3 years and 6 months,the average age is 2 years and 4 months,weight is between 7 and 12 kg,the average weight is 9.5 ± 2.6 kg.Preoperative children have shortness of breath,history of cyanosis and clubbing and some other symptoms.Five cases have atrial septal defect(ASD).Twenty cases of TOF were admitted to hospital for routine examination.The location and size of ventricular septal defect,the degree of aorta riding,the presence or absence of collateral circulation,the presence or absence of collateral circulation and the coronary arteries were examined with color echocardiography.To Improve the above inspection result 256 CT enhanced cardiac imaging examination was conducted,the examination equipment was provided by the Zhengzhou No.7 People's Hospital,equipmet mode: Philips Brilliance iCT of the Netherlands,layer thickness 0.45 mm.Then we got the image data of 256 CT continuous tomography medical Digital Imaging and Communications in Medicine(DICOM).After that,the DICOM image data was imported into Mimics19.0 software(Materialise medical company in Belgium)to optimize the image to reduce the shadow caused by factors such as 256 CT,respiratory motion and heartbeat.Based on 256 CT imaging principle we determined the threshold of cardiac contrast media,myocardium,fat range,and marked.The medical area Mimics software reuse area growth and dynamic area growth algorithm to segment the target area,the Mimics software editing masked,with editorial instructions to split,separate of the internal contrast agent while retaining the normal structure with the abnormal,so we got the data model and they were consistent with the heart and lesions of 20 patients.Finally based on the three-dimensional reconstruction data model using the United States 3DP Unlimited X1000 industrial printer to print a 1: 1 3D solid model.All the twenty patients exposured their heart under general anesthesia,hypothermia,cardiopulmonary bypass and so on.The external cardiac structure was observed and compared with the three-dimensional solid model.After revealing the internal structure of the heart,the size of ventricular septal defect was measured and the data were recorded,we completed the operation.Then collect 20 cases of children with preoperative aortic riding on the degree of coronary artery deformity,collateral circulation and the size of ventricular septal ultrasound reports,and compared with the three-dimensional solid model and intraoperative real situation,record the results.ResultsAll of the 20 cases got the ideal three-dimensional solid model.The reconstructed model was coincident with the heart disease and the size which were seen in the operation.3 cases were right ventricle double outlet which were diagnosed with TOF by preoperative color doppler ultrasound.One case had coronary artery malformations and 2 case had collateral,all of whom were not shown with preoperative color doppler ultrasound.The size of ventricular septal defect in 3D printing group was [(10.98 ± 1.56)mm],compared with preoperative color doppler ultrasound [(9.28 ± 1.66)mm],P<0.05,and when compared with operation group [(11.24 ± 1.45)mm],P>0.05.3D printing showed more accuracy for other vascular malformations.Twenty patients underwent surgery successfully and preoperatively through three-dimensional solid model preoperatively.No postoperative right ventricular outflow tract morphological changes,valve insufficiency,residual shunt complications were found.ConclusionsThree dimensional reconstruction and 3D printing technology can print the threedimensional physical model of the diseased organs,including the internal structure of the heart cavity,the thickness of the wall of the room and the anatomical position and structural relationship of each vessel,can provide intuitive,accurate data information for preoperative communication and medical teaching;Three dimensional reconstruction and 3D printing technology of TOF complex cardiovascular disease diagnosis and treatment was better than heart colour to exceed.It is helpful to plan the operation method,reduce the operation time and the misdiagnosis rate,and increase the success rate of surgery.