99Tcm-PYP延迟及断层显像诊断转甲状腺素蛋白相关心脏淀粉样变的应用价值

目的:探讨⁹⁹Tc^m-焦膦酸盐(PYP)不同采集方法在心脏淀粉样变(CA)诊断与病理分型中的应用。方法:回顾性分析2018年12月至2019年12月间北京协和医院31例临床怀疑CA的患者资料,其中男22例、女9例,年龄21~81(57.2±13.4)岁。患者注射⁹⁹Tc^m-PYP后不同时间行平面显像早期显像(注射后1 h)、延迟显像(注射后2~3 h)]和断层显像(注射后1 h)。以临床诊断为标准,分别采用视觉评分法(≥2分为阳性)和半定量法心脏与对侧肺摄取比值(H/CL)≥1.5诊断为阳性]分析⁹⁹Tc^m-PYP不同采集方法获得的CA及非CA患者的影像学特点。采用单因素方差分析和Bonferroni检验分析数据。结果:根据临床诊断,CA组15例转甲状腺素蛋白相关CA(ATTR-CA)5例、轻链型CA(AL-CA)10例],非CA组16例。5例ATTR-CA患者双时相显像和SPECT/CT显像均为阳性;10例AL-CA患者中3例早期显像阳性,延迟显像和SPECT/CT显像阴性;16例非CA患者双时相显像和SPECT/CT显像均为阴性。延迟期平面显像及断层显像灵敏度均为5/5,特异性均为10/10,阳性预测值均为5/5,阴性预测值均为10/10,准确性均为15/15。31例患者中,转甲状腺素蛋白相关(TTR)突变基因患者16例,其中4例为家族性突变型(ATTRv),表现为⁹⁹Tc^m-PYP显像阳性;12例诊断为非CA,表现为显像阴性。ATTR-CA组与AL-CA组早期显像H/CL(2.11±0.24与1.31±0.07)与延迟显像H/CL(2.02±0.19与1.30±0.05)差异均有统计学意义(F值:75.41和87.15,Bonferroni检验,均P<0.01)。结论:早期平面显像对CA分型存在误诊现象,延迟期平面显像及断层显像结果一致性好,可准确诊断ATTR-CA。⁹⁹Tc^m-PYP显像有助于发现TTR突变基因患者是否合并CA。

Application value of delay-phase 99Tcm-PYP scintigraphy and SPECT imaging for diagnosis of transthyretin-related cardiac amyloidosis

Objective To investigate the application of different imaging methods of ⁹⁹Tc^m-pyrophosphate(PYP)in the diagnosis and pathological classification of cardiac amyloidosis(CA).Methods A total of 31 patients(22 males,9 females,age 21-81(57.2±13.4)years)with suspected CA who underwent ⁹⁹Tc^m-PYP dual-phase scintigraphy(early-phase:1 h,delay-phase:2-3 h)and SPECT/CT(1 h)between December 2018 and December 2019 in Peking Union Medical College Hospital were retrospectively included.Taking clinical diagnosis as the standard,the results of visual score(≥2,positive)and semi-quantitative values(heart to contralateral lung(H/CL)≥1.5,positive)of ⁹⁹Tc^m-PYP uptake in dual-phase scintigraphy and SPECT/CT imaging were analyzed.One-way analysis of variance and Bonferroni test were used to analyze the data.Results Among 31 patients with suspected CA,15 were clinically diagnosed as CA(5 patients with transthyretin-related CA(ATTR-CA)and 10 patients with light chain CA(AL-CA))and 16 were diagnosed as non-CA.All 5 patients with ATTR-CA had positive dual-phase scintigraphy and SPECT/CT imaging results.Three out of 10 patients with AL-CA had positive early-phase scintigraphy whereas negative delay-phase scintigraphy and SPECT/CT imaging results.Sixteen patients who were clinically diagnosed as non-CA had negative dual-phase scintigraphy and SPECT/CT imaging results.The sensitivity(5/5),specificity(10/10),positive predictive value(5/5),negative predictive value(10/10)and accuracy(15/15)of delay-phase scintigraphy and SPECT/CT imaging were the same.Among 31 patients,16 patients carried transthyretin-related(TTR)gene mutation,and 4 of them who clinically diagnosed as variant ATTR(ATTRv)had positive image findings while 12 of them who not clinically diagnosed as CA had negative image findings.There were significant differences in H/CL between ATTR-CA group and AL-CA group in early-phase(2.11±0.24 vs 1.31±0.07)and delay-phase(2.02±0.19 vs 1.30±0.05;F values:75.41 and 87.15,Bonferroni test,both P<0.01).Conclusions ⁹⁹Tc^m-PYP delay-phase scintigraphy and SPECT/CT have high diagnostic efficiencies in ATTR-CA,helping to determine the pathological classification of CA;while early-phase scintigraphy has false positive results.Moreover,⁹⁹Tc^m-PYP imaging is helpful to detect CA in patients with TTR gene mutation.