^(18)F-FDG PET/CT心房显像的方法学研究及在心房颤动患者中的初步应用

Methodological study on atrial ^(18)F-FDG PET/CT imaging and preliminary application in atrial fibrillation

目的探讨适合心房^(18)F-FDG PET/CT显像的方法,并分析心房颤动(简称房颤)患者心房异常摄取的特征。方法前瞻性入组2017年8月至2018年8月间北京朝阳医院69例房颤患者[男43例,女26例,年龄(64±11)岁]行60及120 min ^(18)F-FDG PET/CT双时相显像。另招募10名健康志愿者为对照组[男3名,女7名,年龄(66±4)岁]行60 min ^(18)F-FDG PET/CT显像。采用美国核医学与分子影像学会/美国核心脏病学会/美国心血管计算机断层扫描学会(SNMMI/ASNC/SCCT)指南推荐的方法抑制心肌生理性摄取。图像分析:(1)左心室心肌^(18)F-FDG摄取情况定性分析:0级,左心室心肌摄取低于或等于心血池;1级,轻度高于心血池;2级,明显高于心血池。另观察左心房、左心耳和右心房的^(18)F-FDG摄取情况,高于心血池判定为异常摄取;采用配对χ^(2)检验比较早期相与延迟相各心房及心耳结构异常摄取的比例。(2)定量分析:测定左心房、左心耳、右心房的SUV_(max),并测定左右心房腔的SUV_(mean),计算左心房、左心耳及右心房的靶本比(TBR);采用Wilcoxon符号秩检验分析各心房及心耳结构早期相与延迟相TBR间的差异。采用χ^(2)检验及Mann-Whitney U检验比较房颤患者和对照组心房各结构^(18)F-FDG摄取差异。结果84.8%(67/79)的受试者左心室心肌生理性摄取被有效抑制,仅1例由于左心室摄取较高而影响对左心耳的判读。定性分析结果表明,左心房、右心房及左心耳延迟相异常摄取的比例均高于早期相,其中左心耳差异有统计学意义[27.9%(19/68)与42.6%(29/68);χ^(2)=8.10,P=0.020]。定量分析示,左心房、左心耳及右心房延迟相TBR均高于早期相TBR[左心房:1.1(1.0,1.3)与1.1(1.0,1.2);左心耳:1.2(1.0,1.5)与1.0(0.9,1.2);右心房:1.4(1.1,1.9)与1.3(1.0,1.5);z值:-6.81~-3.42,均P<0.05]。87.0%(60/69)的房颤患者存在心房异常摄取,明显高于对照组[0(0/10);χ^(2)=31.50,P<0.001],其中左心耳、右心房异常摄取比例均明显高于对照组[左心耳:30.4%(21/69)与0(0/10);χ^(2)=4.10,P=0.042;右心房:53.6%(37/69)与0(0/10);χ^(2)=8.00,P=0.001]。结论采用SNMMI/ASNC/SCCT指南推荐的方法抑制心肌的生理性摄取并适当延长采集间隔,有利于观察心房的^(18)F-FDG异常摄取。房颤患者心房^(18)F-FDG摄取增加。

Objective To explore suitable strategies for atrial ^(18)F-FDG PET/CT imaging and analyze the characteristics of abnormal atrial uptake in patients with atrial fibrillation(AF).Methods From August 2017 to August 2018,69 AF patients(43 males,26 females,age(64±11)years)in Beijing Chaoyang Hospital were prospectively enrolled and underwent dual-phase ^(18)F-FDG PET/CT imaging(60 and 120 min postinjection).Additionally,10 healthy controls(3 males,7 females,age(66±4)years)were prospectively enrolled and underwent ^(18)F-FDG PET/CT imaging(60 min postinjection).A comprehensive strategy recommended by the Society of Nuclear Medicine and Molecular Imaging/American Society of Nuclear Cardiology/Society of Cardiovascular Computed Tomography(SNMMI/ASNC/SCCT)guideline was followed to suppress myocardial uptake.Image analysis:(1)^(18)F-FDG uptake of left ventricle was qualitatively analyzed and classified into 3 levels:grade 0,the activity of blood pool exceeded or was equal to myocardial activity;grade 1,myocardial activity was mildly higher than blood pool activity;grade 2,myocardial activity was obviously higher than blood pool activity.^(18)F-FDG uptake in the left atrium(LA),left atrial appendage(LAA)and right atrium(RA)higher than that in blood pool were defined as abnormal.Pairedχ^(2) test was used to compare the rates of abnormal uptake in atrial structures between two phases.(2)Quantitative analysis:^(18)F-FDG uptake in all atrial structures were quantitatively analyzed by measuring SUV_(max),and left atrial cavity and right atrial cavity were quantitatively analyzed by measuring SUV_(mean).The target to background ratio(TBR)was calculated.Differences of TBR between two phases were analyzed by Wilcoxon signed rank test.Differences of ^(18)F-FDG uptake in atrial structures between patients with AF and healthy controls were analyzed by Mann-Whitney U test andχ^(2) test.Results Most subjects(84.8%,67/79)achieved sufficient myocardial suppression.In one patient,the interpretation of LAA was affected by left ventricle uptake.The incidence of abnormal uptake of LA,LAA and RA in delayed phase were higher than those in early phase,but only the difference of LAA was significantly different(27.9%(19/68)vs 42.6%(29/68);χ^(2)=8.10,P=0.020).TBR of LA,LAA and RA in delayed phase were all significantly higher than those in early phase(LA:1.1(1.0,1.3)vs 1.1(1.0,1.2);LAA:1.2(1.0,1.5)vs 1.0(0.9,1.2);RA:1.4(1.1,1.9)vs 1.3(1.0,1.5);z values:from-6.81 to-3.42,all P<0.05).There were 87.0%(60/69)of AF patients with abnormal atrial FDG accumulation,which was significantly higher than that of the control group(0/10;χ^(2)=31.50,P<0.001).In LAA and RA,the incidences of abnormal accumulation were significantly higher in AF than those in the control group(LAA:30.4%(21/69)vs 0(0/10);χ^(2)=4.10,P=0.042;RA:53.6%(37/69)and 0(0/10);χ^(2)=8.00,P=0.001).Conclusions Using the method recommended by the SNMMI/ASNC/SCCT guideline to suppress the physiological uptake of the left ventricle and appropriately extending the interval is conducive to observing the abnormal ^(18)F-FDG uptake in the atrium.The uptake of ^(18)F-FDG in the atrium of patients with AF is increased.