三维SPACE磁共振序列在精确测量体内乳房硅凝胶假体体积中的应用

Application of three・dimensional SPACE magnetic resonance imaging in accurate measurement ofimplant volume in breast surgery

目的探讨应用可变反转角快速自旋回波(sampling perfection with application optimized contrast using different flip angle evolutions,SPACE)序列磁共振硅凝胶激发序列检査预估患者体内乳房硅凝胶假体体积的准确性与可靠性。方法(1)2018年10月至12月应用T2序列、SPACE水激发序列(T2-spc-H2O).SPACE硅凝胶激发序列(T2-spc-Silicone)扫描体外假体,再通过ITK-SNAP软件对体外10个乳房硅凝胶假体的体积进行测量,探究最优的体积测量方法,并研究假体形变状态及T2-spc-Silicone序列层厚对体积测量误差的影响。(2)对2017年3月至2019年5月武汉同济医院收治的13例无并发症患者及6例假体并发症患者行T2-spc-Silicone序列磁共振检査,验证其测量体内硅凝胶假体体积的准确性及一致性。并让2名具有5年以上工作经验的影像科医师和整形外科医师分别使用T2-spc-Silicone序列图像和ITK-SNAP软件测量假体体积,以验证其可重复性。利用Prism&0软件进行分析,两样本均值比较应用配对/检验,多样本均值比较应用One・Way AN0VAo P<0.05为差异具有统计学意义。结果体外假体体积测量结果:T2序列,T2-spc-H20序列、T2・spc・Silicone序列的体积测量误差分别为(42.19±2.31)ml、(23.27±1.55)ml.(6.28±1.22)ml,T2-spc-Silicone序列的体积测量误差少于前两者(F==195.3,P<0.001);在层厚为0.5 mmx 0.5 mmxO.5 mm到5.0 mmx5.0 mmx5.0 mm时,假体形变对体积测量误差没有影响(F=1.36,P=0.22)©在假体剧烈形变状态下,T2-spc-Silicone序列层厚从0.5 mmxO.5 mmxO.5 mm到5.0 mmx 5.0 mmx5.0 mm的假体体积测量误差差异无统计学意义(F=1.22,P=0.29)O无并发症患者体内假体磁共振扫描,T2-spc-Silicone序列的体积测量误差为(8.82±0.99)ml。假体并发症患者体内实际假体体积与T2-spc-Silicone序列测量体积分别为(225.9±11.94)ml和(226.4±12.76)ml,2组数据比较差异无统计学意义(/==0.31/=0.76)。2名测量者假体体积测量结果的内部相关系数ICC=0.997,大于0.8,Cronbach's a为0.993(0.986-0.997)(P<0.001)c结论SPACE磁共振硅凝胶激发序列测量体内乳房硅凝胶假体体积具有良好的准确性、一致性和可重复性。假体的形变和SPACE序列的层厚对假体体积测量误差的影响不明显。

Objective The study is to assess the accuracy and reliability of three-dimensionalsimulated magnetic resonance imaging with silicone-excitation SPACE ( sampling perfection with application optimized contrast using different flip angle evolutions) sequence for estimating implant volume. Methods(1) MRI examinations of 10 silicone implants ( Wuhan Tongji Hospital from October 2018 to December2018) were performed with T2, H20-excitation SPACE sequence ( T2-spc-H2O) and silicone-excitationSPACE sequence ( T2-spc-Silicone) to find the most accurate method to estimate implant volume by ITKSNAP.The effect of implant deformation and slice thickness of T2-spc-Silicone on volume measurementwere investigated. ( 2) 13 normal patients and 6 patients with implant complications ( Wuhan TongjiHospital from March 2017 to May 2019) were enrolled for testing the accuracy and reliability of T2-spc-Silicone for volume measurement in vivo. The data were analyzed using Prism 8. 0 software. The pairedstudent Z-test was used to compare the difference of two groups. One-way ANOVA was used to compare thedifference of multiple groups. P V 0. 05 was considered statistically significant. Results The absolutevolume differences of T2, T2-spc-H2O, T2-spc-Silicone were (42. 19±2. 31) ml, ( 23. 27± 1.55 ) ml and(6. 28± 1. 22) ml. The absolute volume differences of T2-spc-Silicone group was significantly less than T2-spc-H2O and T2 group in vitro( F= 195. 3 , P<0. 001 ). No significant difference ( F = 1.36, P = 0. 22) wasshown between the normality group and the deformation group for estimating the volume of implants with theslice thickness of SPACE increased from 0. 5 mm x 0. 5 mm x 0. 5 mm to 5. 0 mm x 5. 0 mm x 5. 0 mm.Besides, the slices thickness of SPACE from 0. 5 mmxO. 5 mmxO. 5 mm to 5. 0 mmx5. 0 mmx5. 0 mm didnot significantly affect the accuracy of volume measurement of the implants in deformation state ( F= 1. 22,P = 0. 29). The measurement error of SPACE was (& 82±0. 99) ml in normal patients. Moreover,there wasno significant difference between measured volume [ ( 226. 4 ± 12. 76 ) ml ] and actual volume of implants[(225. 9± 11. 94) ml ] ( i = 0. 31 , P = 0. 76 ) in patients with implant complications. The result showedexcellent intraobserver reliability ( ICC = 0. 997) and internal consistency ranged from 0. 986 to 0. 997 ( P<0. 001). Conclusions The method to measure implant volume by silicone-excitation SPACE sequence haddesirable accuracy and reliability. The deformation of the implant and the slice thickness of the SPACEsequence did not exhibit a significant effect on the accuracy of volume measurement.