不同图像采集和处理对^67Ga显像质量及病灶探查的影响

目的分析平面显像、非衰减校正（NAC）断层显像和CT衰减校正（AC）断层显像等^67Ga显像图像采集和处理模式对图像质量和病灶判断的影响。方法用美国GE Millennium^TM VG 5型SPECT／CT仪对31例活动期肺结节病患者行^67Ga平面显像、胸部NAC断层显像;并对断层图像行CTAC。图像分析：双盲法阅片,判断平面图像、AC和NAC断层图像的图像质量及病灶数;测量病变与周围正常组织的放射性计数,并测量其比值。采用SPSS10．0软件,行配对t检验和,检验。结果图像质量按照平面显像、NAC、AC顺序依次提高（χ^2=25．880,P〈0．001）。以活动期结节病患者SPECT／CT示放射性增高的肺门、纵隔淋巴结为“病灶”,平面显像发现“病灶”70个,漏诊“病灶”8个;NAC、AC断层图像均发现“病灶”78个。NAC图像中“病灶”的放射性计数明显低于AC图像中“病灶”的放射性计数（15．240±8．865和67．241±35．049,t=-17．230,P〈0．001）。和NAC图像比较,AC图像“病灶”与肺的放射性比值增高（t=-7．520,P〈0．001）,“病灶”与肝（t=3．298,P=0．001）及“病灶”与腰椎（t=7,032,P〈0．001）的比值降低。结论^67Ga平面显像因前后组织放射性分布叠加,可能导致漏诊。^67Ga NAC断层显像能够较为准确地确定病变淋巴结的三维位置,但图像计数率低、噪声较大。AC断层图像虽未能增加检出的病灶数,但能有效提高NAC计数率,改善图像质量。     

双核素心肌灌注-代谢显像评价存活心肌对心肌梗死患者择期血运重建术后左心功能的影响

目的采用^99Tc^m-MIBI加^18F-FDG双核素心肌灌注-代谢显像（DISA）评价冠心病心肌梗死患者有无存活心肌,以判断择期血运重建后存活心肌对左心功能的影响。方法选择确诊心肌梗死患者91例,行DISA。根据超声心动图（UCG）结果将患者分为心功能不全（A组）和心功能正常（B组）2组,在行PCI术后1,3和6个月观察UCG结果。采用SPSS13．0软件进行统计学处理,2组间均值比较采用t检验,率的比较采用,检验。结果A组灌注平均缺损（9．8±3．5）个节段,B组灌注平均缺损（5．4±2．6）个节段;2组相比,t=6．87,P〈0．01。A组代谢平均缺损（7．5±3．4）个节段,B组代谢平均缺损（4．6±2．8）个节段,2组相比,t=4．46,P〈0．01。A组检出存活心肌173个节段,占37．8％（173／458）,B组检出188个节段,占61．2％（188／307）,2组相比,x2=40．61,P〈0．001。A组灌注显像总评分（SPS）为（Z8．43±11．86）分,代谢显像总评分（SMS）为（20.17±8．52）分,（代谢-灌注）总评分之差（SDS）为（0．39±3．17）分;B组SPS为（21．36±9．54）分,SMS为（15．19±5．74）分,SDS为（-12．72±4．55）分,2组相比,t=3．15,3．32和15．59,P均〈0．01。A组存活心肌≥4个节段的LVEF升高差值（ALVEF）为（12．81±2．62）％,明显高于B组的（5．90±1．91）％,t=16．33,P〈0．001;左心室舒张末期内径回缩差值（△LVEDd）为（-13．13±4．20）mm,也明显高于B组（-7．75±2．31）mm,t=6．86,P〈0．001;A组存活心肌〈4个节段的△LVEF和△LVEDd则明显低于B组,t=3．25和4．92,P均〈0．01。结论心肌梗死区是否有存活心肌及存活心肌节段数可能是择期血运重建后左心功能改善程度的重要影响因素。     

^99Tc^m—MIBI静息门控心肌灌注显像在心肌梗死干细胞移植治疗中的价值

目的用^99Tc^m-甲氧基异丁基异腈（MIBI）静息门控心肌灌注显像的方法,评价急性心肌梗死（AMI）患者自体骨髓间质干细胞（MSC）移植术治疗的疗效。方法AMI患者31例,均行经皮冠状动脉介入治疗（PCI）术,其中18例患者作为试验组,于PCI术后行自体MSC移植术治疗,PCI术后拒绝行细胞移植治疗的13例患者作为对照组。于PCI术前,术后1,3和6个月进行^99Tc^m-MIBI静息门控心肌灌注断层显像,评价心肌血流灌注及心功能改善程度。统计学处理采用SPSS11．0软件,行t检验。结果所有患者术后1个月放射性稀疏节段数明显减少,术后3个月和6个月放射性缺损节段数试验组（2．37±1．09和2．21±0．93）较对照组（3．24±0．93和3．21±1．05）明显减少（t=2．32,2．79,P均〈0．05）;与术前[（35．4±16．7）％和（32．8±15．9）％]相比,术后6个月试验组[（57．2±14．3）％]和对照组[（44．8±11．7）％]患者左心室射血分数（LVEF）均显著升高（t=4．27,2．18,P均〈0．05）,试验组患者LVEF明显高于对照组（t=2．58,P〈0．05）。结论心肌梗死患者自体MSC移植术后,应用^99Tc^m-MIBI静息门控心肌灌注显像随访和评价疗效有一定临床价值。     

SPECT门控心肌灌注显像相位图在冠状动脉慢性闭塞病变患者中的应用价值

目的分析冠状动脉慢性闭塞病变（CTO）患者SPECTG—MPI相位图,探讨其在CTO患者中的应用价值。方法回顾性分析2012年中国CTO俱乐部的21例CTO患者[均为男性,年龄37～77（平均56．6）岁]。患者术前完成^99Tc^m-MIBIG—MPI和^18F—FDG心肌代谢显像。应用G—MPI所测LVEF评价左心室功能,并将患者分为2组：正常组（11例,LVEF〉60％）和非正常组（10例,LVEF≤60％）。采用两样本t检验或Wilcoxon秩和检验比较2组患者的LVEF、灌注／代谢缺损、左心室收缩同步性参数,分析CTO患者中同步性参数[峰相位,相位标准差（SD）,相位图带宽、偏斜及陡度]与LVEF的线性相关性。结果21例CTO患者闭塞时间为3—60个月,相位SD和相位图带宽均高于健康参考值,分别为（30．8±28．3）°与（14．2±5．1）°,t=3．09;（58．1±39．4）°与（38．7±11．8）°,t=2．61,均P〈0．05。这2个参数与LVEF均呈负相关（r=-0．785、-0．883,均P〈0．01）,而相位图偏斜和陡度与LVEF均呈正相关（r=0．755、0.666,均P〈0．01）。正常组患者LVEF高于非正常组患者：（69．3±4．7）％与（44．7±13．0）％,t=-5．65,P〈0．01;灌注缺损比例低于非正常组：4．0％与16．0％;Z=-2．23,P〈0．05;代谢缺损比例差异无统计学意义（Z=-1．82,P〉0．05）。正常组相位SD及相位图带宽显著低于非正常组,分别为（18．7±19．0）°与（44．2±31．6）°,t=2．21;（36．4±12．7）°与（82．1±45．4）°,t=3．08,均P〈0．05。相位图偏斜、陡度正常组高于非正常组-5．11±0．75与3．55±1．05,t=-3．89;30．77±10．49与15．66±10．12．t=-3．35,均P〈0．01。结论CTO患者左心室收缩同步性较健康人差,核素显像相位图同步性参数可有效预测左心室泵功能。     

腺苷负荷99Tcm—MIBI心肌显像在冠状动脉造影慢血流患者中的应用

目的探讨腺苷负荷99Tcm-甲氧基异丁基异腈（MIBI）心肌显像与冠状动脉（简称冠脉）造影慢血流现象的关系。方法44例患者均经冠脉造影及腺苷负荷99TcmMIBI心肌血流灌注显像,分析比较冠脉造影阳性组（P—CAG）12例,冠脉慢血流组（CSF）22例以及冠脉正常血流组（NCF）10例患者临床资料、腺苷心肌负荷显像改变、冠脉造影结果与腺苷负荷心肌显像的关系。结果采用方差分析、t检验或X^2检验比较。结果3组临床资料（包括年龄、性别和危险因素：高血压史、高脂血症及糖尿病发病率）差异均无统计学意义（年龄：t=0．27,0．54和0．59;性别：矿：0．92;危险因素：X^2=1．23;P均〉0．05）;CSF组冠脉心肌梗死溶栓疗法（TIMI）血流帧数明显多于NCF组（33．7±5．5和17．6±3．9,t=-9．58,P〈0．001）。P—CAG组12例,腺苷负荷心肌显像阳性率100％（12／12）;CSF组22例,阳性率77．3％（17／22）;NCF组10例,2例阳性。半定量靶心图分析示腺苷负荷试验心肌缺血范围（人均缺血节段数）CSF组多于NCF组（1．06±0．77和0．91±0．80,t=-2．02,P〈0．05）,少于P—CAG组（2．41±0．79,t=4．54,P〈0．001）。靶心图记分心肌缺血程度显示CSF组大于NCF组（8．01±6．06和2．73±2．60,t=-2．07,P〈0．05）,小于P—CAG组,但差异无统计学意义（14．07±12．77,t=1．44,P〉0．05）。结论腺苷负荷心肌灌注阳性显像中部分患者伴有冠脉造影慢血流现象,这为有明显胸痛症状但冠脉造影阴性的患者提供了诊断和治疗依据。     

特发性扩张型心肌病合并甲状腺功能减退加重心肌损伤的影像学评价

目的通过^99Tcm-MIBI心肌灌注SPECT／^18F—FDG心肌代谢PET显像和心脏MRI延迟增强成像（cMRI—LGE）,探讨特发性扩张型心肌病（IDC）合并甲状腺功能减退（简称甲减）与心肌损伤的关系。方法2010年10月至2012年12月诊断为IDC的连续病例63例[男42例,女21例,平均年龄（52±11）岁]入选,患者均进行血浆TT3、TT4、FT3、FT4和TSH全自动化学发光免疫法测定、^99Tcm-MIBI心肌灌注SPECT／^18F—FDG心肌代谢PET显像和cMRI—LGE。利用标准17节段模型进行心肌节段分析,灌注／代谢图像分成4种类型：正常灌注／代谢、灌注／代谢不匹配、灌注／代谢轻中度匹配、灌注／代谢完全匹配;cMRI-LGE图像分为无延迟强化、壁间强化和透壁强化。通过x^2检验进行分组数据的比较。结果根据所测血浆激素水平,患者被分成甲状腺功能（简称甲功）正常组（53例）和甲减组（10例）。甲功正常组正常灌注／代谢的心肌节段数所占的比例明显高于甲减组：71.8％（647／901）和57．6％（98／170）,x^2=13．50,P〈0．001;而灌注／代谢不匹配的心肌节段比例则低于甲减组：17．8％（160／901）和31．2％（53／170）x^2=16．20,P〈0．001。甲功正常组cMRI—LGE无延迟强化的心肌节段比例明显高于甲减组,分别为88．0％（793／901）和69．4％（118／170）,x^2=35．70,P〈0．001;但壁间强化的心肌节段比例则低于甲减组,分别为4．8％（43／901）和24．1％（41／170）,x^2=74．70,P〈0．001。结论^99Tc^m-MIBI心肌灌注SPECT／^18F—FDG心肌代谢PET显像和cMRI—LGE证实甲减能够加重IDC患者的心肌损伤。SPECT／PET可以检测出更多的慢性缺血／存活心肌,而cMRI-LGE可以检测出更多的心肌纤维化病变,两者结合能提供更全面的心肌损伤信息。     

门控心肌灌注显像评价肥厚型心肌病心肌缺血的临床价值

目的探讨门控心肌灌注显像评价肥厚型心肌病患者心肌缺血情况的临床应用价值。方法选取核素心肌灌注显像均为阳性的69例临床确诊的肥厚型心肌病住院患者,分为冠状动脉造影阳性（管腔狭窄／〉50％）和阴性（管腔狭窄〈50％）2组,对比其心肌缺血的门控心肌灌注显像特点,并进行两样本t检验。结果冠状动脉造影阳性组19例,其中9例表现为可逆性心肌缺血,10例表现为不可逆性心肌缺血;8例射血分数（EF）升高,为（69．1±2．8）％,11例下降,为（42．8±2．1）％。冠状动脉造影阴性组50例,其中37例表现为可逆性心肌缺血,13例表现为不可逆性心肌缺血;38例EF值升高,为（70．8±4．0）％,12例下降,为（48．9±2．7）％。2组缺血范围[（29．7±17．8）％与（24．1±16．0）％]、缺血严重程度和EF值组间差异均有统计学意义（t=9．28,16．51和2．65,P〈0．001,〈0．001和〈0．01）。结论门控心肌灌注显像发现肥厚型心肌病合并冠心病患者心肌缺血情况要严重于无合并冠心病患者;冠心病对于改变肥厚型心肌病的病理生理过程、自然病程和预后可能起重要作用。     

脑SPECT显像对高压氧治疗脑外伤后脑缺血疗效判断的价值

目的探讨SPECT脑血流灌注显像对高压氧（HBO）治疗脑外伤继发脑缺血患者疗效判断的价值。方法将65例脑外伤继发脑缺血患者按随机数字表法分为HBO治疗组和常规治疗组,在治疗前后分别进行脑血流灌注SPECT显像,应用计算机感兴趣区（ROI）技术,在横断面图像上采用局部镜像比值（Ra）法判断脑缺血病灶,Ra≤0．9视为异常。对治疗前后的脑血流灌注减低区Ra值进行比较。数据间的比较行t检验。结果HBO治疗组治疗前后局部脑血流（rCBF）减低区Ra值分别为0．58±0．11和0．82±0．12（t=7．327,P〈0．01）,常规治疗组治疗前后rCBF减低区Ra值分别为0．61±0．13和0．73±0．12（t=2．153,P=0．038）;HBO治疗组和常规治疗组缺血灶rCBF增加值分别为0．24±0．08和0．12±0．06（t=2．571,P=0．015）。结论SPECT脑血流灌注显像可灵敏地反映HBO治疗脑外伤后脑缺血前后rCBF变化,可用于HBO治疗疗效的评价。     

放射性核素显像及心血管造影对Fontan术后肺血流灌注的随访

目的通过放射性核素显像和心血管造影,观察心外全腔静脉一肺动脉连接（ETCPC）手术后完全旷置右心对肺血流灌注的长期影响。方法回顾性分析1990年3月至2005年12月间行ETCPC手术的53例[男29例,女24例,平均年龄（10．8±6．1）岁]患者资料。其中43例随访资料完整的患者均于术后1个月内（早期）及5年（中期）随访时行”1rcmIMAA肺灌注显像和心血管造影检查,并分别计算各肺段灌注比值、PVR及肺动脉指数。采用配对t检验分析患者早、中期的肺血流分布变化。结果”TcmMAA肺灌注显像结果示,中期随访与早期随访患者的肺总放射性计数值差异无统计学意义[（701．91±8．26）×10^3计数／s和（698．93±12．0）×103计数／s;t=0．38,P〉0．05],右肺／左肺灌注比值（1．06±0．01和1．03±0．03;t=1．12,P〉0．05）及下腔静脉右肺灌注比值（0．61±0．06和0．60±0．06;t=0．74,P〉0．05）无有意义的改变,全肺上段／下段比值下降（0．72±0．20和0．75±0．01;t=2．54,P〈0．05）,肺下叶背段灌注比例升高（0．12±0．00和0．10±0．03;t=2．16,P〈0．05）。中期随访患者的PVR下降[（142．98±2．61）dyn·s·cm-5（1dyn·S·cm-5=0．1kPa·S·L-1）和（146．95±2．54）dyn·s·cm-5;t=2．08,P〈0．05],腔静脉压下降[（9．35±0．24）mmHg（1mmHg：0．133kPa）和（9．95±0．23）mmHg;t=2．69,P〈0．05],动脉血氧饱和度未见明显改变[（92．70±0．30）％和（92．86±0．29）％;t=1.12,P〉0．05]。5例患者术后早期存在肺动脉造影与核素显像明显不匹配。结论在研究功能性肺血流灌注方面,放射性核素显像效果优于心血管造影。Fontan循环的长期弱动力、无搏动血流会引起肺血流坠积性重新分布。     

^18F-FDG肿瘤显像前低碳水化合物饮食对心肌放射性摄取的影响

目的探讨^18F—FDG肿瘤显像前采用低碳水化合物饮食以减少心肌放射性摄取的可行性。方法选取2011年4月至2012年1月行^18F—FDG肿瘤显像患者70例,按完全随机法将其分为对照组（34例）和实验组（36例）。对照组显像前一天晚餐为正常饮食,实验组为低碳水化合物饮食。所有患者检查当天空腹,并在注射^18F—FDG前抽血检测血糖、血清游离脂肪酸、胰岛素及酮体水平。行双探头符合线路显像,目测分析心肌FDG摄取程度,进行分级评分：0分,不显影;1分,摄取低于肝脏;2分,摄取与肝脏相当;3分,摄取高于肝脏;4分,显著摄取。计算心肌与肝脏放射性摄取比值（H／L）。采用两样本t检验、Wilcoxon秩和检验和直线相关分析处理数据。结果实验组心肌^18F—FDG摄取明显低于对照组,H／L分别为0．94±0．57和1．50±1．04,差异有统计学意义（t=-2．75,P〈0．05）。实验组血清游离脂肪酸和酮体水平[（0．671±0．229）mmol／L、（0．88±0．60）mmol／L]较对照组[（0．547±0．207）mmol／L、（0．57±0．32）mmol／L]显著升高（t=2．38和2．67,均P〈0．05）;2组血糖和胰岛素水平分别为（5．28±1．06）mmol／L、（35．16±33．70）pmol／L和（5．19±0．78）mmol／L、（41．64±35．13）pmol／L,差异均无统计学意义（t=0．39和-0．79,均P〉0．05）。心肌摄取^18F-FDG程度与血清游离脂肪酸和酮体水平均呈负相关（r=-0．40和-0．33,均P〈0．01）,但与血糖和胰岛素水平相关性均无统计学意义（r=-0．02和0．13,均P〉0．05）。结论^18F-FDG肿瘤显像前采用低碳水化合物饮食可以降低心肌对^18F—FDG的摄取,从而减少其对周围病灶检出的干扰。     

心肌灌注显像对症状性冠状动脉心肌桥患者的临床应用价值

目的 探讨心肌灌注显像对症状性冠状动脉(以下简称冠脉)心肌桥患者的临床应用价值.方法 回顾性分析19例因胸痛、胸闷等症状行冠脉造影排除阻塞性冠脉狭窄,诊断为心肌桥并接受运动-静息99Tcm-甲氧基异丁基异腈(MIBI)心肌灌注显像的患者资料,分析心肌灌注显像结果,并与运动心电图、冠脉造影结果比较.应用Stata 7.0软件,对符合正态分布的计量资料行t检验比较,用χ2检验分析组间频数差别.结果 19例症状性心肌桥患者冠脉造影示收缩期冠脉狭窄程度为(65.4±22.1)%,18例为左前降支肌桥、1例为左前降支合并左回旋支肌桥.运动-静息心肌灌注显像示心肌缺血10例、正常9例,其中心肌缺血位于前壁和(或)心尖部8例、下壁1例、后侧壁和后间壁1例;心肌灌注显像诊断心肌缺血的阳性率为52.6%(10/19),明显高于运动心电图的21.1%(4/19)=4.07,P<0.05.19例心肌桥患者按Nobel分级法,Ⅰ级狭窄5例、Ⅲ级狭窄6例、Ⅲ级狭窄8例;Ⅰ级狭窄患者中1例心肌灌注显像心肌缺血阳性,Ⅱ级狭窄患者中2例阳性,Ⅲ级狭窄患者中7例阳性.心肌桥患者心肌灌注显像心肌缺血组收缩期冠脉狭窄明显高于心肌灌注显像正常组[(78.0±4.7)%与(52.8±6.7)%,t=3.06,P<0.01],2组肌桥长度差异无统计学意义[(15.1±2.1)mm与(11.8±1.0)mm,t=1.43,P>0.05].结论 运动-静息心肌灌注显像能有效评价症状性心肌桥患者所致心肌缺血,明确心肌桥与临床症状的关系及其临床意义.     

Reduction of infracardiac intestinal activity by a small amount of soda water in technetium-99m tetrofosmin myocardial perfusion scintigraphy with adenosine stress

Background  In technetium (Tc)-99m myocardial perfusion imaging (MPI), intestinal activity often interferes with the assessment of myocardial perfusion of the inferior wall. We examined whether a small amount of soda water prevents intestinal activity and improves image quality of the inferior wall in Tc-99m tetrofosmin MPI. Methods and Results  Ninety-five patients referred for 1-day rest/stress Tc-99m tetrofosmin MPI were assigned to one of two groups automatically, according to the data when they underwent MPI: the soda water group (n=63) ingested 100 mL soda water just before image acquisition after adenosine stress, and the control group (n=32) underwent no intervention. The frequency of intestinal activity was assessed visually on planar images. The inferior myocardial wall and the abdominal activity adjacent to the myocardium were assessed quantitatively on three different planar images during stress, and the mean inferior wall-to-abdomen (1/A) count ratio was calculated. The frequency of intestinal activity was 69.8% in the soda water group, and 90.6% in the control group (P=.038). The I/A count ratio was significantly higher in the soda water group than in the control group (1.98±0.51 vs 1.50±0.35, respectively, P<.0001, ±SD). Conclusions  The intake of 100 mL of soda water improves intestinal activity and improves the image quality of the inferior wall.     

Simultaneous assessment of left ventricular wall motion and myocardial perfusion with technetium-99m-methoxy isobutyl isonitrile at stress and rest in patients with angina: comparison with thallium-201 SPECT

The newly developed technetium-99m (99mTc) isonitriles can be used for the simultaneous evaluation of ventricular function and myocardial perfusion. We compared technetium-99m hexakis-2-methoxy isobutyl isonitrile [( 99mTc] MIBI) derived first-pass left ventricular wall motion at stress and rest with simultaneous myocardial perfusion defined by [99mTc]MIBI SPECT. These results were then compared with 201TI SPECT. We examined 28 patients with coronary artery disease; 25 had a previous myocardial infarction. We found concordance between segmental wall motion and myocardial perfusion imaging in defining normal, ischemic, and infarcted myocardium in 68% and 69% of segments using [99mTc]MIBI and 201TI respectively. The best agreement between wall motion and myocardial perfusion was seen in the inferior wall, while most of the discrepancies were found at the apex. Agreement between [99mTc]MIBI and 201TI SPECT myocardial perfusion was seen in 93% of segments. Technetium-99m-MIBI appears to be an ideal radiopharmaceutical for the simultaneous evaluation of ventricular function and myocardial perfusion during stress and at rest.     

Assessment of cardiac abnormalities in Duchenne's muscular dystrophy by (99m)Tc-MIBI gated myocardial perfusion imaging

Cardiac abnormalities in Duchenne's muscular dystrophy (DMD) are often detected in adult patients and their early detection is warranted. Studies have suggested that myocardial damage may be detected by cardiovascular magnetic resonance imaging or by echocardiography at the early stage of DMD. We aimed to identify early changes of cardiac abnormalities in children with DMD by technetium 99m-methoxyisobutylisonitrile ((99m)Tc-MIBI) gated myocardial perfusion imaging (GMPI). Forty-three boys aged 3 to 14 years (mean age 8.2±3.6 years) with DMD and 12 age-matched normal boys as control were studied by G-MPI. These patients were at early stage according to previous studies on DMD. Uptake of (99m)Tc-MIBI in 7 regional walls and 17 segments of the left ventricle were visually analyzed. Quantitative gated single photon emission tomography (QGSSPET) analysis of myocardium was performed to evaluate left ventricular function (LVEF). Gated myocardial perfusion imaging revealed cardiac abnormalities in 81.4% of all patients. Regional perfusion decrease involving multiple walls of LV was present. Four of the patients demonstrated mild abnormalities (11.4%), 7 moderate (20.0%) and 24 severe abnormalities (68.6%). Evident LV ejection fraction (EF) decrease (42.1±6.4%) and dilation with globally poor perfusion were found in three patients, aged 10 to 14, which had significant difference compared with the control group (EF=58.4±4.7%, P=0.001). The rest cases, aged 3 to 9 years, had normal LVF. In conclusion, from the 35 cases of DMD patients (aged 3 to 14 years), regional myocardial perfusion decrease was detected in multiple walls by (99m)Tc-MIBI G-MPI at an early stage, while left ventricular function decrease (3/35, 8.6%) appeared late at about 10 years of age or older as compared with the control group in this study.     

Assessing the effect of increasing injection activity for myocardial perfusion imaging in overweight patients

In our previous publication, we proposed to increase the injection activity for overweight patients. We have now implemented this for our patients, i.e. increasing the activity for patients above 99 kg. In the present study, we audited whether this increased activity for overweight patients improved the myocardial counts effectively and also whether it improved the image quality for these patients. 125 consecutive normal myocardial perfusion studies were included into the study. The total left ventricular myocardial count was calculated, as was the total left ventricular myocardial volume using the Cedar Sinai QPS program. The myocardial count per millilitre of the myocardium (c ml(-1)) was correlated with patient weight using regression analysis. There was no significant difference (p = 0.120) among the mean myocardial counts for patients over 99 kg (n = 40, 1548 c ml(-1)) compared with patients in the 70-79 kg range (n = 26, 1746 c ml(-1)). This indicates that the previously proposed algorithm for adjusting injection activity maintains the count density in the myocardium and should be used for all patients over 99 kg. There was, however, a significant steady decrease with increased weight in the myocardial counts for patients under 100 kg (p<0.001), a range in which injection activity was not adjusted for weight. To correct for this, we now propose that the injection activity should be adjusted for all patients over 80 kg, using the previously proposed algorithm.     

The effects of solid food in prevention of intestinal activity in Tc-99m tetrofosmin myocardial perfusion scintigraphy

BACKGROUND: The aim of this study was to investigate the effect of a standardized meal on intestinal activity in technetium 99m tetrofosmin myocardial perfusion scintigraphy. METHODS AND RESULTS: The study population consisted of 60 patients (42 men and 18 women; mean age, 56 +/- 8 years) referred for myocardial perfusion imaging. All patients underwent same-day exercise-rest Tc-99m tetrofosmin single photon emission computed tomography (SPECT) imaging. All patients were given 200 mL of milk 15 minutes after the injection for the exercise SPECT study and just after the injection for the first rest SPECT study. None of the patients ate or drank between the exercise and the first rest SPECT studies. After the first rest SPECT study, 30 patients (meal group) were given a standardized meal of solid food and liquid to increase the volume of the stomach, and a second rest SPECT image was obtained 30 minutes after the end of the first rest SPECT study. In 30 patients (control group) a second rest SPECT image was obtained 30 minutes after the end of the first rest SPECT study, but this group did not eat or drink in this interval. The effect of the meal on intestinal activity was evaluated both visually and quantitatively. Frequency of intestinal activity was assessed visually on SPECT images. Inferior myocardial wall and abdominal activity adjacent to the myocardium was quantitatively assessed on 3 different planar projections in the rest studies, and the mean inferior wall-to-abdomen count ratio was calculated. In the meal group, inferior wall-to-abdomen count ratios in the first and second rest studies were 1.48 +/- 0.3 and 2.09 +/- 0.4, respectively (P <.0001), and in the control group, 1.41 +/- 0.2 and 1.40 +/- 0.2 (P >.05), respectively. The frequency of intestinal activity was 63% (n = 19) in the first rest SPECT study and 10% (n = 3) in the second study in the meal group (P <.0001); it was 66% (n = 20) in the first rest SPECT study and 76% (n = 23) in the second study in the control group (P >.05). CONCLSUIONS: Our results indicate that filling of the stomach with a meal of solid food and liquid before rest acquisition may provide a high target-to-nontarget ratio. This simple modification may reduce the frequency of intestinal activity of Tc-99m-labeled radiopharmaceuticals in myocardial perfusion imaging.     

~(99)Tc~m-NOET门控心肌灌注SPECT评价冠心病的价值

目的 评价~(99)Tc~m-双(N-乙氧基,N-乙基-二硫代氨基甲酸酯)氮化锝(~(99)Tc~m-NOET)静息门控断层心肌灌注显像对冠心病患者的诊断价值.方法 疑诊为冠心病的45例患者注射925 MBq~(99)Tc~m-NOET后1h用SPECT行静息门控心肌灌注显像,获得舒张未期容积(EDV)、收缩未期容积(ESV)、左室射血分数(LVEF)等心功能参数和舒张末期容积灌注、局部射血分数、局部室壁活动和室壁增厚度4个靶心图.所有患者在1周内行冠状动脉造影,将冠状动脉狭窄≥50%定为病变血管.根据冠状动脉造影结果将其分为心肌梗死组、心肌缺血组和对照组三组.结果 ~(99)Tc~m-NOET静息门控SPECT诊断冠心病的灵敏度和特异度分别为68.42%和83.33%.心肌梗死组的心功能参数[EDV=(129.32±9.14)ml,ESV=(80.97±9.49)ml,LVEF=(40.15±3.28)%]与对照组[EDV=(80.91±3.12)ml,ESV=(30.12±1.79)ml,LVEF=(63.51±1.04)%]相比,统计学差异有显著性(EDV:F=22.103,ESV:F=32.277,LVEF:F=42.604,均为P＜0.01),心肌缺血组的心功能参数[(EDV=(70.83±3.46)ml,ESV=(25.13±2.85)ml,LVEF=(65.55±2.62)%]与对照组相比,统计学差异无显著性意义.心肌梗死组左室心肌共分为460个节段,其中209个节段局部灌注、局部射血分数、局部室壁活动和室壁增厚度4个靶心图均异常.局部灌注异常的节段共328个节段.伴有局部射血分数、局部室壁活动和室壁增厚度异常分别有250个、240个和276个节段.局部灌注异常的节段与局部射血分数、局部室壁活动和室壁增厚度异常的节段不完全匹配.结论 ~(99)Tc~m-NOET静息门控心肌灌注显像对冠心病的诊断有较大临床应用价值,所获得的整体心室功能参数在心肌梗死的评价中有优越性,但对心肌缺血的诊断价值不大.心肌梗死中存在有不少的局部灌注与心肌室壁功能异常节段的不匹配,对心肌存活的评价有帮助.