The Valuation Of MRI For Filling Displacement Extravasation After Facial Polyacrylamide Injection

Part one: the value of IDEAL technique in the application of polyacrylamide hydrophilic gel injectionObjective: To observe the MRI features of extravasation of polyacrylamide hydrogel facial shift after surgery,compared with frequency selective saturation method(FS),IDEAL(Iterative Dixon water-fat separation technology with echo asymmetry and least-squares estimation),short TI inversion recovery(STIR)inhibitory effect on the detection rate of filler and the surrounding soft tissue facial fat,evaluate the value of MRI.Methods: The clinical data of 60 patients with facial injection in our hospital from October 2012 to December 2016 were collected and analyzed.All patients had been injected or filled with polyacrylamide hydrophilic gel in the face,and the injection time was 7-10 years.At the same time by using a frequency selective saturation method,IDEAL technology,short inversion time inversion recovery scan on image quality and fat suppression effect for subjective evaluation,and the measurement of the signal-to-noise ratio and contrast to noise ratio,the objective evaluation of image quality and fat suppression effect,finally the data were analyzed by statistics.Results:By polyacrylamide as water soluble material,mixed with a certain proportion of water to form a hydrogel,so rich in water,and water in magnetic resonance is similar in T1 FLAIR showed low signal,signal with surrounding muscle and soft tissue are similar;but in IDEAL and T2 WI frequency selective saturation method and short inversion time reversal to recover this fat suppression sequences showed marked high signal on,can clearly show the shift in polyacrylamide hydrogel injected clearance,gland.Three kinds of calculation technique showed that rate of polyacrylamide hydrogel,by 2 test,T2 WI frequency selective saturation method and IDEAL technique were statistically significant(χ2=8.93,P=0.01),T2 WI frequency selective saturation method and STIR sequence were statistically significant(χ2=6.28,P=0.01),IDEAL technology and STIR sequence comparison was not statistically significant(χ2=0,P=1).The nasal root morphology showed that the rules of the subjective evaluation methods,is located in the center of the coil position,T2 WI frequency selective saturation method,IDEAL technology,short inversion time inversion recovery can be fat suppression,there was no statistically significant difference(P>0.05),clear image quality,contrast showed significant,but in the cheeks,chin,temporal the anatomic structure of curved frequency selective saturation method and short inversion time inversion recovery fat suppression effect than IDEAL method(P<0.05),the difference was statistically significant.In the objective evaluation method,calculate the signal-to-noise ratio and contrast to noise ratio,the data obtained from the t test,the T2 WI frequency selective saturation method and IDEAL technique were statistically significant(P=0.00),T2 WI frequency selective saturation method and STIR sequence were statistically significant(P=0.00),IDEAL and STIR sequences were statistically significant(P=0.00),showed that IDEAL technology in fat suppression effect is obviously superior to the T2 WI frequency selective saturation method and short inversion time inversion recovery sequence.Conclusion: Polyacrylamide hydrogel(polyacrylamide hydrophilic gel)in magnetic resonance has characteristic display,IDEAL technology on the detection rate of facial prosthesis and the surrounding fat suppression effect is superior to the T2 WI frequency selective saturation method and short inversion time inversion recovery,contribute to the clinical diagnosis to provide better information,to determine whether prosthesis displacement,extravasation.The second part of the SFOF-VR in the application of polyacrylamide hydrogel injectionObjective: To evaluate the clinical value of SFOF-VR and VR technique in the treatment of facial polyacrylamide hydrogel injection by reconstruction of the surface of the prosthesis.Methods: The clinical data of 60 patients with facial injection in our hospital from October 2012 to December 2016 were collected and analyzed.All patients were injected or filled with polyacrylamide hydrogel in the face,injection time of 7~10 years.Formulate appropriate scanning sequence,the image postprocessing on AW4.5 workstation,using SFOF-VR(separating,fusing,opacifying and false-coloring-volume rendering,decomposition,fusion,transparent,pseudo color volume reconstruction(volume)technology and VR rendering technology,volume rendering),respectively,3D reconstruction of the 60 sets of images.Results: The SFOF-VR image processing technology and VR technology are divided into 4 levels(0,1,2,3),the total score of VR technology for 51 points,the average score was 1.62 + 0.58,the total score of SFOF-VR technology for 178 points,the average score was 2.83 + 0.22,Mann-Whitney test was used for statistical analysis,the data of the two groups of P<0.01.There was statistical significance.SFOF-VR technology can independently or fuse with the facial soft tissue to show the position and the boundary of the prosthesis,and can reconstruct the image in the multi angle and omni-directional,which is more clear and intuitive than the VR image.Conclusion: SFOF-VR technique can display the position of the prosthesis on the face in an intuitive way,and it can be used as the first choice for the image processing of magnetic resonance imaging after the injection of polyacrylamide hydrogel.