PET/CT诊断肺癌的准确度及其证实偏倚校正的研究

目的:评价正电子发射断层显像(positron emission tomography/computed tomography,PET/CT)诊断肺癌的准确度,分析其证实偏倚校正后的灵敏度及特异度,为临床客观而全面地认识PET/CT诊断的结果提供依据.材料和方法:用最大似然估计值法对PET/CT诊断肺癌的灵敏度和特异度进行校正.结果:传统有偏估计的灵敏度为94.21%(95%CI:90.89%～97.53%),校正证实偏倚后的灵敏度为87.07%(95%CI:81.36%～92.78%),两者95%可信区间有交集,其差异无统计学意义;传统有偏估计的特异度为44.07%(95%CI:31.39%～56.73%),校正证实偏倚后的特异度为65.57%(95%CI:56.82%～74.31%),两者95%可信区间无交集,其差异具有统计学意义,证实偏倚校正后的特异度高于校正前.结论:PET/CT诊断肺癌的灵敏度较高.证实偏倚的存在,影响对PET/CT诊断肺癌的准确度评价.     

Fibro Touch瞬时弹性成像诊断慢性乙型肝炎合并肝癌患者肝纤维化程度应用研究

目的探讨Fibro Touch瞬时弹性成像技术在诊断慢性乙型肝炎合并肝癌患者肝纤维化程度中的应用价值。方法选取2015年5—8月第二军医大学附属东方肝胆外科医院收治的慢性乙型肝炎合并肝癌患者446例,其中,测试组288例,验证组158例。所有患者均根据病理标准诊断肝纤维化程度(S0~S4期);同时,术前接受Fibro Touch瞬时弹性成像检查,采用受试者工作特征曲线(ROC)评价Fibro Touch瞬时弹性成像技术诊断慢性乙型肝炎合并肝癌患者肝纤维化程度的敏感度与特异度。结果根据病理标准诊断,测试组患者中,肝纤维化程度S0期35例,S1期47例,S2期83例,S3期37例,S4期86例;验证组患者中,S0期27例,S1期18例,S2期45例,S3期16例,S4期53例。根据Fibro Touch瞬时弹性成像诊断,测试组中,无或轻度肝纤维化(S0/S1期)、明显肝纤维化(S2/S3/S4期)、严重肝纤维化(S3/S4期)及肝硬化(S4期)的ROC曲线下面积分别为0.89(95%可信区间0.85~0.93),0.86(95%可信区间0.82~0.90),0.84(95%可信区间0.80~0.88)及0.85(95%可信区间0.81~0.89);验证组中,则分别为0.94(95%可信区间0.90~0.97),0.91(95%可信区间0.86~0.95),0.87(95%可信区间0.81~0.92)及0.86(95%可信区间0.79~0.91)。测试组诊断≥S1期的敏感度与特异度分别为88.14(95%可信区间83.5~91.9)与77.14(95%可信区间59.9~89.6),验证组分别为84.96(95%可信区间77.7~90.6)与81.48(95%可信区间61.9~93.7);测试组诊断≥S2期的敏感度与特异度分别为82.04(95%可信区间76.1~87.0)与69.51(95%可信区间58.4~79.2),验证组分别为78.07(95%可信区间69.4~85.3)与86.96(95%可信区间73.7~95.1);测试组诊断≥S3期的敏感度与特异度分别为82.11(95%可信区间74.2~88.4)与66.06(95%可信区间58.3~73.2),验证组分别为79.71(95%可信区间68.3~88.4)与79.12(95%可信区间69.3~86.9);测试组诊断=S4期的敏感度与特异度分别为76.74(95%可信区间66.4~85.2)与72.28(95%可信区间65.6~78.3),验证组分别为71.70(95%可信区间57.7~83.2)与81.31(95%可信区间72.6~88.2)。结论 Fibro Touch瞬时弹性成像技术对诊断慢性乙型肝炎合并肝癌患者肝纤维化程度具有一定的准确性,可作为术前评估的参考。     

双源CT和3.0T磁共振评价左心室功能的相关性研究

目的 对双源CT(dual-source CT,DSCT)和3.0T磁共振(magnetic resonance imaging,MRI)评价的左心室功能参数进行比较,评价其相关性.方法 心脏病患者20例,行双源CT和3.0T MRI检查,分别计算左心室舒张末期容积(end-diastolic volume,EDV)、收缩末期容积(end-systolic volume,ESV)及射血分数(ejection fraction,EF),以磁共振结果为标准,与双源CT结果进行对比,行相关性分析及一致性检验.结果 双源CT检查结果:EDV、 ESV和EF值分别是(118.80±19.43) ml,(43.65±18.06) ml,(63.75±10.59)%;相对的MRI结果分别是(102.39±19.41) ml,(47.82±19.25) ml,(54.34±11.15)%.DSCT测得的EDV 及EF值分别较MRI高估约16.42 ml(95%可信区间9.59～23.24)和9.41%(95%可信区间6.92～11.90),而DSCT测得的ESV较MRI低估约4.17 ml(95%可信区间-8.69～0.35);其Pearson相关系数(r)分别为EDV/ 0.718(P<0.001),ESV/ 0.868(P<0.001),EF/0.881(P<0.001 ) ;Spearman 秩相关系数 (rs)分别为 EDV/0.736(P<0.001),ESV/0.760(P<0.001),EF/0.645(P=0.002).结论 DSCT和3.0T MRI在评价左心室心功能上有很好的相关性,DSCT在一定程度上可以作为"一站式"的心脏检查工具.     

18F-FDG PET心肌代谢显像对左心室室壁瘤患者长期预后的价值

目的 评估18F-脱氧葡萄糖(FDG)PET心肌代谢显像对左心室室壁瘤患者长期预后的价值.方法 对70例左心室室壁瘤患者[超声心动图示左心室射血分数(LVEF)为(36±8)%]行99Tcm-甲氧基异丁基异腈(MIBI)SPECT心肌灌注显像和18F-FDG PET心肌代谢显像,对经冠状动脉造影确诊的左心室室壁瘤患者进行随访,计算室壁瘤部位、非室壁瘤部位以及左心室心肌灌注和代谢积分,以及灌注-代谢不匹配分(MMS).MMS≥2.0为心肌存活.室壁瘤部位心肌不存活者中,药物治疗为组1,手术治疗为组2;室壁瘤部位心肌存活者中,药物治疗为组3,手术治疗为组4.心源性死亡和心脏事件为随访终点.以Kaplan-Meier方法获得生存曲线,并用Log-rank法比较率的差异.结果 组1至组4患者例数分别为14,23,10和23例.随访1～105(72±32)个月,16例患者发生心源性死亡.组3的心源性年死亡率为11.6%,高于组4的1.5%(X2=12.87,P<0.0001),也高于组1的4.8%(X2=4.13,P<0.05)和组2的2.2%(χ2=10.46,P=0.001).Cox回归多因素分析显示室壁瘤部位的MMS[风险比(HR)1.40,95%可信区间(CI)为1.11～1.75,P=0.003]和血运重建术(HR 0.35,95%CI为0.18～0.69,P=0.002)是预测心源性死亡的独立危险因子.结论 18F-FDG PET心肌代谢显像和99Tcm-MIBI SPECT心肌灌注显像对于室壁瘤患者的治疗方案制定及长期预后估测有重要意义.     

256层CT心电前置门控及回顾门控冠状动脉成像质量及辐射剂量比较

目的 比较256层CT前置门控冠状动脉CTA与回顾门控检查方法的成像质量及辐射剂量,探讨256层CT前置门控冠状动脉扫描方法的临床应用价值及局限性.方法 回顾分析177例冠状动脉256层CTA检查患者,其中前置门控86例,回顾门控91例.将冠状动脉主要分支分为9个节段评价,采用4分法评价图像质量,≥3分为可评价节段.采用t检验比较两种方法组可评价节段的百分比、患者的有效辐射剂量及图像噪声.结果 前置门控组86例中98.8%节段(765/774)为可评价节段.回顾门控组91例中99.6%节段(816/819)可评价.2组图像质量差异有统计学意义(t=2.51,P=0.01).心率<75次/min时,前置门控与回顾门控组的可评价节段分别为99.8%(647/648),99.7%(718/720),图像质量的差异无统计学意义(t=1.90,P>0.05).≥75次/min时,2组的可评价节段分别为93.6%(118/126)和99.0%(98/99).2组的可评价率差异有统计学意义(t=3.57,P<0.05).前置门控组及回顾门控组的有效辐射剂量分别为(4.4±0.5)和(10.3±1.5)mSv(t=33.4,P<0.00),前置门控扫描的剂量明显小于回顾门控扫描,下降幅度达60.0%.结论 256层CT前置门控冠状动脉扫描方法较回顾门控方法剂量显著降低,两种扫描方法得到的图像质量均较好.在低心率组图像质量两种方法相近,而高心率组前置门控较回顾门控法有差距.     

门控心肌显像对心脏起搏器植入早期左心室功能和结构的研究

目的 应用门控心肌显像观察心脏起搏器植入后早期患者左心室收缩功能与结构的变化.方法 患者27例,男9例,女18例,年龄(65.1±9.5)岁.其中起搏心室感知心室R波抑制型(VVI)起搏器组15例,起搏双腔感知双腔P波或R波抑制型(DDD)起搏器组12例.采用门控心肌显像方法测定患者起搏器植入前及植入后早期[随访(4.6±1.5)个月]自身心律或起搏器工作状态下左心室功能参数值:左心室射血分数(LVEF),左心室舒张末容积(EDV),左心室收缩末容积(ESV)及左心室收缩时间.按左心室室壁活动靶心图将室壁活动度分为缺损、稀疏及正常3级.植入前后相比,有下列一项即为左心室功能重构:LVEF增加或降低10%及以上,室壁活动度改变1级及以上,左心室收缩时间延长或缩短1个时间段及以上;结构重构:EDV增加或降低10%以上.结果 (1)左心室功能重构:27例患者中,26例(96.3%;VVI组15例,DDD组11例)出现功能重构.26例中6例(23.1%;VVI组4例,DDD组2例)LVEF升高,8例(30.8%;VVI组4例,DDD组4例)LVEF降低,12例(46.2%;VVI组7例,DDD组5例)LVEF无变化.(2)结构重构:27例中13例(48.1%;VVI组10例,DDD组3例)出现结构重构.13例中4例(VVI组3例,DDD组1例)LVEF升高,3例(均为VVI组患者)LVEF降低,6例(VVI组4例,DDD组2例)LVEF无变化.结论 心脏起搏器植入后早期即可发生左心室功能重构,约半数患者出现左心室结构重构.心脏永久起搏器植入在患者心脏获得电生理学益处时,可能对左心室的功能和结构带来不利影响.     

201Tl定量门控心肌灌注体层显像与99mTc-红细胞门控心血池显像测定左心室射血分数的对比研究

目的 探讨201Tl定量门控心肌灌注体层显像与99mTc-红细胞门控心血池显像测量左心室射血分数(LVEF)的相关性.方法 72例受检者接受201Tl静息门控心肌灌注体层显像,用AUTOQUANT 4.21软件测量LVEF,并与24 h内的静息99mTc-红细胞平衡法门控心血池显像结果进行比较.结果 ①门控心肌灌注体层显像与门控心血池显像测量LVEF值的结果呈明显正相关(r=0.554,P=-0.000),两种方法无统计学差别(t=1.194,P＞0.05).②不同疾病组之间两种测量方法无统计学差异(P值均大于0.05).③门控心肌灌注体层显像及门控心血池显像测量的LVEF值分别为(64.68±10.77)%和(62.46±8.99)%,门控心肌灌注体层显像测量的LVEF值要比门控心血池显像高出3.55%.结论 201Tl门控心肌灌注体层显像与99mTc-红细胞门控心血池显像测量LVEF值的相关性好且结果准确,但门控心肌灌注体层显像的LVEF测量值要稍高于门控心血池显像.     

血清25-羟基维生素D水平与老年脑小血管病变相关性研究

目的探讨血清25-羟基维生素D[血清25(OH)D]水平与老年脑小血管病变的相关性。方法回顾性分析北部战区总医院2015—2016年收治的163例腔隙性脑梗死患者(腔隙性脑梗死组)、120例脑白质病变患者(脑白质病变组)及158例同年龄段健康体检者(健康组)的临床资料,比较3组研究对象的血清25(OH)D水平,记录3组研究对象血清25(OH)D充足、缺乏、不足的比例,并进行血清25(OH)D与腔隙性脑梗死、脑白质病变的相关性分析。结果腔隙性脑梗死组血清25(OH)D缺乏患者比例高于健康组(43.6%比23.4%),脑白质病变组血清25(OH)D缺乏患者比例高于健康组(39.2%比23.4%),差异均有统计学意义(P<0.05)。血清25(OH)D水平每降低10 ng/ml时,腔隙性脑梗死组回归系数为0.24(95%可信区间为0.03～0.48,P<0.05),脑白质病变组比值比为2.11(95%可信区间为1.50～3.26,P<0.05);血清25(OH)D缺乏时,腔隙性脑梗死组回归系数为0.53(95%可信区间为0.05～0.89,P<0.05),脑白质病变组比值比为2.85(95%可信区间为1.28～6.32,P<0.05)。结论血清25(OH)D水平与老年腔隙性脑梗死和脑白质病变显著相关,可通过监测血清25(OH)D水平预防腔隙性脑梗死和脑白质病变发生。     

64层CT前瞻性心电门控冠状动脉成像中重叠时间设置的合理应用

目的 评价基于前瞻性心电门控技术的重叠时间(padding time,PT)设置应用于心率<75次/min、心率变异<5次/min患者CT冠状动脉造影(CTCA)的价值.方法 本研究共选取拟行CTCA检查的病 人130例(心率<75次/min,心率变异<5次/min),依据病人体质量指数选择管电流(300～800 mA),管电压设置为120 kV.前瞻门控组(A组)分3个亚组,A1组:心率<65次/min采集期相设定为75%,PT设置为100 ms;A2组:心率<65次/min,心率变异为0～1次/min者采集期相设定为75%,PT设置为0 ms;A3组:心率为65～75次/min者采集期像设定为60%,PT为200 ms.回顾门控组(B组)采用ECG管电流调制技术,35%～85%满电流输出,非诊断期相以最低管电流输出.比较A、B组的辐射剂量及图像质量.P<0.05认为差异具有统计学意义.结果 A组与B组图像质量评分差异无统计学意义(Z=-0.783,P=0.433).前瞻门控组CTCA辐射剂量平均(4.60±1.69) mSv,回顾门控组CTCA辐射剂量平均(15.59±3.90) mSv,差异有统计学意义(F=27.88,t=-14.31,P=0.00),使用前瞻门控降低了70.49%的辐射剂量.结论 依据心率及心率变异的PT合理设置可以扩大前瞻门控技术的适用范围,然而对于0 ms的PT设置需谨慎.     

冷疗应用于烧伤现场急救处理现状Meta分析

目的系统评价在我国烧伤现场应用冷疗进行急救处理的现状,为提升烧伤现场急救水平提供帮助。方法检索PubMed、EMbase、中国期刊全文数据库及万方数据库,并辅以参考文献追溯和手工检索,查找我国烧伤流行病学有关现场急救方式和急救知识掌握情况的回顾性研究,时间为2000年1月至今。由两位研究员依据纳入和排除标准独立筛选文献、提取资料及纳入研究质量评价,采用R 3.5.1软件进行Meta分析。结果纳入将烧伤现场急救作为重要指标的文献17篇,共17 146例患者;将烧伤现场急救知识掌握作为重要指标的文献6篇,共5 510例患者。全国烧伤现场应用冷疗进行急救处理的患者比例为14.76%(95%可信区间11.24～18.67,P<0.05);东南沿海地区烧伤现场应用冷疗进行急救处理的患者比例为16.97%(95%可信区间10.91～21.78,P<0.05),中西部内陆地区比例为13.16%(95%可信区间8.31～18.93,P<0.05),两个地区比较,差异无统计学意义(P>0.05);2000年1月至2009年12月全国烧伤现场应用冷疗进行急救处理的患者比例为11.82%(95%可信区间7.75～16.62,P<0.05),2010年1月至今比例为19.23%(95%可信区间11.81～27.95,P<0.05),两个时间段比较,差异无统计学意义(P>0.05)。全国掌握正确烧伤现场急救知识的患者比例为6.18%(95%可信区间1.81～12.91,P<0.05)。结论针对我国居民烧伤后现场急救的研究文献数量少、质量差,冷疗应用比例低,烧伤现场急救处理在我国烧伤救治中未引起足够重视。     

82Rb PET myocardial perfusion imaging is superior to 99mTc-labelled agent SPECT in patients with known or suspected coronary artery disease

Purpose

We compared the quality, interpretive confidence and interreader agreement between SPECT and PET myocardial perfusion imaging (MPI) in the same group of patients.

Methods

The study group comprised 27 patients (age 55?±?8.5?years, 12 men) with known or suspected coronary artery disease (CAD) who had undergone gated rest/stress MPI with ^99mTc-labelled agent SPECT (with and without attenuation correction, AC), and subsequent clinical confirmation with ⁸²Rb PET. Three experienced readers blinded to the clinical information interpreted all MPI studies.

Results

Interreader agreement was significantly superior for PET studies than for SPECT studies. Following consensus interpretation, the quality of 22?% of the non-AC SPECT studies, 33?% of the AC SPECT studies and 63?% of the PET studies was assessed as excellent or good (p?=?0.016). Interpretations were definitely normal or abnormal in 7?% of non-AC SPECT studies, 30?% of AC SPECT studies and 85?% of PET studies (p?=?0.046). In 13 patients who had received either invasive coronary angiography or CT angiography with no significant CAD, the true-positive rate for significant CAD was higher for PET, and the true-negative rate was equal for PET and AC SPECT, and lower for non-AC SPECT.

Conclusion

⁸²Rb PET MPI, used as a confirmatory test after SPECT, offers improved image quality, interpretive confidence and interreader agreement.     

Paradoxical septal motion from prior coronary artery bypass graft surgery does not impact left ventricular mechanical dyssynchrony by gated myocardial perfusion imaging

Background

Phase analysis of gated myocardial perfusion imaging (MPI) provides automated and reproducible assessment of left ventricular (LV) mechanical dyssynchrony (LVMD) (phase standard deviation [SD]). Many patients undergoing gated MPI have history of prior coronary artery bypass graft surgery (CABG). The latter is often associated with paradoxical septal wall motion (PSM). The effect of prior CABG and PSM on LVMD has not been evaluated.

Methods and Results

From the single-photon emission computed tomography (SPECT) and positron emission tomography (PET) MPI clinical database maintained at the Cleveland Clinic, we identified 200 consecutive patients with SPECT (100 control with normal LV ejection fraction [EF], MPI, and QRS?<?120?ms; and 100 with LVEF?<?35%), and 631 patients with LVEF?<?35% with gated PET. Patients with QRS????120?ms, bundle branch block, ventricular pacing or isolated non-CABG surgery were excluded. There were 162 patients with gated SPECT (46 with prior CABG), and 568 with gated PET (220 with prior CABG) that were left for analysis. Phase SD was derived using Emory Cardiac Toolbox (ECTb) (for gated SPECT) and Corridor 4DM (4DM) (for gated SPECT and PET images). Multivariate linear regression analysis was performed to assess whether prior CABG was an independent predictor of worse LV mechanical dyssynchrony. After adjusting for patients?? demographics, co-morbidities, medications, and MPI data, history of prior CABG was not and independent predictor of LV mechanical dyssynchrony (P?=?.67 with 4DM, P?=?.97 with ECTb) in patients undergoing gated SPECT or among patients undergoing gated PET imaging (P?=?.18).

Conclusions

Although paradoxical septal wall motion is commonly seen after cardiac surgery, prior CABG does not affect or impact LV mechanical dyssynchrony indices measured from gated SPECT or PET images. Whether dyssynchrony measurements with echocardiography that has higher temporal resolution might uncover intraventricular delays, remains to be determined.     

Adenosine stress rubidium-82 PET/computed tomography in patients with known and suspected coronary artery disease

BACKGROUND: Integrated positron emission tomography/computed tomography (PET/CT) is increasingly being utilized for myocardial perfusion imaging (MPI). However, there is a potential for increased imaging artifact compared with standard PET due to the different temporal resolution of PET and CT. We reviewed the diagnostic accuracy of adenosine stress Rb myocardial perfusion PET/CT to detect obstructive coronary artery disease (CAD) on invasive angiography at our institution. METHODS AND RESULTS: Seventy-five patients were included, 23 (13 men, mean age 55.8+/-11.8 years) with low likelihood of CAD and 52 (28 men, mean age 67.1+/-11.4 years) with intermediate to high pretest probability of disease. Coronary angiography was performed only in the latter 52 patients on average within 17 days of the MPI study. The test characteristics of PET/CT MPI were assessed using a threshold of >or=50 and >or=70% stenosis in one or more major coronary artery on invasive angiography. Dedicated software was used for registration, processing, and interpretation. Consensus interpretation of the tomographic PET slices using a 4-point scale (1=definitely normal, 2=probably normal, 3=probably abnormal, 4=definitely abnormal) was done by two readers blinded to clinical information. RESULTS: All MPI studies in the 23 low likelihood patients were normal. In the remaining 52 patients using a stenosis severity>or=50%, global sensitivity and specificity, negative and positive predictive value for detection of CAD were 86, 100, 57, and 100%. Using a stenosis severity>or=70%, these values changed to 90, 83, 71, and 87%. CONCLUSION: Adenosine stress Rb MPI using PET/CT with manual registration demonstrates diagnostic accuracy comparable with that of traditional PET MPI.     

Improvement in PET myocardial perfusion image quality and quantification with flurpiridaz F 18

Rubidium-82 (⁸²Rb), the currently commercially available radiotracer for positron emission tomography (PET) myocardial perfusion imaging (MPI), has led to wide availability of PET-MPI for stress-rest imaging. Compared to SPECT MPI, myocardial perfusion PET images have higher spatial and contrast resolution, are less affected by radiotracer scatter, benefit from more precise attenuation correction, and allow dynamic first pass imaging. In addition, PET imaging allows assessment of myocardial function at peak stress and measurement of absolute myocardial blood flow, thus providing critical data not available with SPECT imaging. Further enhancements of the high quality of PET perfusion images may be realized by technologies under development such as respiratory gating, combined respiratory, and ECG gating to generate “motion-frozen” cardiac images, automated patient motion correction software, and high-definition PET, which reduces distortions introduced by the circular geometry of the scanner. Early studies indicate that the experimental PET radiopharmaceutical flurpiridaz F 18 provides high-quality, high-resolution myocardial perfusion images that may enable improved clinical MPI, and has properties well suited to optimized performance by application of these quantitative analytic technologies.     

Automated quantitative Rb-82 3D PET/CT myocardial perfusion imaging: Normal limits and correlation with invasive coronary angiography

Background

We aimed to characterize normal limits and to determine the diagnostic accuracy for an automated quantification of 3D 82-Rubidium (Rb-82) PET/CT myocardial perfusion imaging (MPI).

Methods

We studied 125 consecutive patients undergoing Rb-82 PET/CT MPI, including patients with suspected coronary artery disease (CAD) and invasive coronary angiography, and 42 patients with a low likelihood (LLk) of CAD. Normal limits for perfusion and function were derived from LLk patients. QPET software was used to quantify perfusion abnormality at rest and stress expressed as total perfusion deficit (TPD).

Results

Relative perfusion databases did not differ in any of the 17 segments between males and females. The areas under the receiver operating characteristic curve for detection of CAD were 0.86 for identification of ??50% and ??70% stenosis. The sensitivity/specificity was 86%/86% for detecting ??50% stenosis and 93%/77% for ??70% stenosis, respectively. In regard to normal limits, mean rest and stress left ventricular ejection fraction (LVEF) were 67%?±?10% and 75%?±?9%, respectively. Mean transient ischemic dilation ratio was 1.06?±?0.14 and mean increase in LVEF with stress was 7.4%?±?6.1% (95th percentile of 0%).

Conclusion

Normal limits have been established for 3D Rb-82 PET/CT analysis with QPET software. Fully automated quantification of myocardial perfusion PET data shows high diagnostic accuracy for detecting obstructive CAD.     

Prognostic significance of dipyridamole-induced ST depression in patients with normal 82Rb PET myocardial perfusion imaging.

Recent studies have shown that vasodilator-induced ischemic electrocardiographic (ECG) changes have incremental prognostic value over normal SPECT myocardial perfusion imaging (MPI) and identify patients at higher risk for cardiac events. The prognostic value of vasodilator-induced ischemic ECG changes in the setting of normal PET MPI has yet to be determined. We sought to determine the prognostic importance of dipyridamole-induced ischemic ECG changes in patients with normal 82Rb PET myocardial perfusion images. METHODS: Between 2000 and 2003, 2,029 consecutive patients undergoing dipyridamole stress 82Rb PET at the University of Ottawa Heart Institute were evaluated. Patients with normal PET MPI and interpretable ECGs were enrolled. Electrocardiograms were assessed for ST depression or elevation and patients were categorized into those with and without dipyridamole-induced ischemic ECG changes. Images were graded using the 17-segment model. Follow-up information was obtained by telephone interview, from hospital records, or from treating physicians. All cardiac events (cardiac death, nonfatal myocardial infarction [MI], percutaneous coronary intervention, coronary artery bypass grafting, or angiography) were verified with hospital records. RESULTS: Of the 629 enrolled patients with normal PET MPI, 72 patients had dipyridamole-induced ischemic ECG changes. There was no significant difference between the 2 groups in the combined endpoint (cardiac death, nonfatal MI, and revascularization) at follow-up (mean +/- SD, 27.1 +/- 13 mo). There were no cardiac deaths in either group. One (1.4%) patient with ischemic ECG changes had a nonfatal MI (0.6% annual event rate). Two (2.8%) patients with ischemic ECG changes required revascularization compared with 11 (2.0%) in the nonischemic ECG group. CONCLUSION: Normal 82Rb PET confers an excellent prognosis regardless of dipyridamole-induced ST depression.     

Day-to-day variability of global left ventricular functional and perfusional measurements by quantitative gated SPECT using Tc-99m tetrofosmin in patients with heart failure due to coronary artery disease

BACKGROUND: Although myocardial gated single photon emission computed tomography (SPECT) is routinely used for functional measurements in patients with coronary artery disease (CAD) and heart failure, day-to-day variability of left ventricular ejection fraction (LVEF), left ventricular (LV) volumes, and global perfusion scoring has not yet been investigated. METHODS AND RESULTS: In 20 consecutive patients with CAD and an LVEF lower than 40% who routinely underwent a resting tetrofosmin gated SPECT study, we performed an additional gated SPECT study at rest 1 to 5 days later under the same circumstances. LV volumes and LVEF were calculated from the gated SPECT data by commercially available software (QGS). Myocardial perfusion was scored visually by use of a 20-segment, 5-point scoring method. For global LV function and perfusion, agreement between data was investigated by use of Bland-Altman plotting. The 95% limits of agreement found by Bland-Altman analysis were -0.9% +/- 6.0% for LVEF, 3 +/- 20 mL for LV end-diastolic volume, and 4 +/- 20 mL for LV end-systolic volume. CONCLUSION: In CAD patients with an LVEF lower than 40%, day-to-day variability of measurements of global myocardial function and perfusion is quite similar to interobserver and intraobserver variability. Day-to-day variability of global LV functional parameters obtained by gated cardiac SPECT is fairly small, which indicates that myocardial gated SPECT can be used in daily clinical practice to determine changes in global LV function and perfusion over time in patients with diminished LV function.     

Prediction of functional recovery after primary PCI using the estimate of myocardial salvage in gated SPECT early after acute myocardial infarction

Purpose

Primary percutaneous coronary intervention (PCI) in acute myocardial infarction (AMI) aims to achieve myocardial salvage (MS). Because the reference method for measuring MS requires myocardial perfusion imaging (MPI) after tracer injection before PCI, alternative approaches have been proposed, but none has gained wide acceptance. Gated SPECT MPI can assess infarct size (IS), but can also show myocardial stunning. Thus, we compared functional and perfusion abnormalities early after AMI to estimate MS, and to predict left ventricular ejection fraction (LVEF) recovery at follow-up.

Methods

We studied 120 patients with AMI. Gated SPECT MPI was performed early (before hospital discharge) and at 6 months after AMI to measure IS, MS and functional outcome. MS was defined as the difference between the number of segments with abnormal thickening (i.e. the stunned area or area at risk) and the number of segments with abnormal perfusion (i.e. the final IS), expressed as a percentage of the total number of segments in the AHA model. LVEF was calculated using quantitative gated SPECT.

Results

The area at risk was 40?±?25%, IS was 17.3?±?16% and MS was 22?±?19%. Early LVEF was 46.6?±?11.6% and late LVEF was 51.4?±?11.6%, with 54 patients showing at least an increase in LVEF of more than 5 units. ROC analysis showed that MS was able to predict LVEF recovery with an area under the curve (AUC) of 0.79 (p?<?0.0001), and using a cut off >23% detected LVEF recovery with 74% sensitivity and 71% specificity. Conversely, IS was associated with an AUC 0.53 (not significant).

Conclusion

MS assessed by a single early gated SPECT MPI study can accurately predict LVEF evolution after primary PCI for AMI.

     

Comparison of gated PET with MRI for evaluation of left ventricular function in patients with coronary artery disease.

The aim of this study was to compare left ventricular (LV) volumes and regional wall motion determined by PET with those determined by the reference technique, cardiovascular MRI. METHODS: LV end-diastolic volume (LVEDV), LV end-systolic volume (LVESV), and LV ejection fraction (LVEF) were measured and regional wall motion was scored in 38 patients with chronic coronary artery disease by both gated (18)F-FDG PET and MRI. A 9-segment model was used for PET and MRI to assess regional wall motion. RESULTS: Good correlations were observed between MRI and gated PET for all parameters (r values ranging from 0.91 to 0.96). With PET, there was a significant but small underestimation of LVEDV and LVEF. Mean +/- SD LVEDV, LVESV, and LVEF for MRI were 131 +/- 57 mL, 91 +/- 12 mL, and 33% +/- 12%, respectively, and those for gated PET were 117 +/- 56 mL, 85 +/- 51 mL, and 30% +/- 11%, respectively. For regional wall motion, an agreement of 85% was found, with a kappa-statistic of 0.79 (95% confidence interval, 0.70-0.89; SE, 0.049). CONCLUSION: LV volumes, LVEF, and regional wall motion can be assessed with gated (18)F-FDG PET and correlate well with these parameters assessed by MRI.