~(99m)Tc-MIBI心肌灌注显像一日和两日检查方案的效果比较

以前认为,采用一日方案做运动和静息~(99m)Tc-MIBI心肌灌注显像会形成本底过高,留存在腹部的较多放射性会妨碍心肌下壁灌注缺损的观察.本文结果表明,做~(99m)Tc-MIBI,心肌灌注显像时,采用一日和两日方案的图像质量相似,不会影响灌注缺损的检测,差别只是在于一日方案要用较大的药物剂量.方法:用~(99m)Tc-MIBI检查了34例(31～76岁)患冠心病概率低于5%的无症状志愿者.其中,17例采用一日检查方案,另17例采用两日检查方案.一日检查方案:先做静息心肌灌注显像,用370MBq(10mCi)~(99m)Tc-MIBI溶于1ml生理盐水静脉推注,再注射10～20ml生理盐水,随即用多晶体γ相机做首次通过法心血管造影.一小时后做SPECT静息心肌灌注显像,再加左前斜位45°平面显像,约需40分     

~(99m)Tc-MIBI心肌灌注显像评价心肌缺血范围和左室收缩功能的效果

为了评价的~(99m)Tc-MIBI心肌灌注显像的临床应用效果,作者检查了42例男性冠心病人:第一组22例心绞痛病人(平均58岁),作了~(99m)Tc-MIBI和~(201)Tl运动后和静息心肌灌注显像.~(99m)Tc-MIBI剂量为555MBq(15mCi),注射后1.5～2小时显像.运动和静息时的SPECT显像分别在两天进行.~(201)Tl剂量为74MBq(2mCi).第二组病人(平均56岁)有心肌梗塞史,只做静息显像,另加做~(99m)Tc标记自身红细胞作首次通过心室造影,并从该组病人的~(99m)Tc-MIBI灌注显像的冠状和矢状切面来估算左室射血分数(EF)及与心室造影的EF作比较.     

良恶性骨病摄取~(99m)Tc-MIBI与~(99m)Tc-MDP的对比研究

~(99m)Tc-MIBI是一种心肌灌注剂,但近来发现它用于骨肿瘤显像效果可靠.对73例良、恶性骨病进行~(99m)Tc-MIBI与~(99m)Tc-MDP对比显像,以评价MIBI用于各种骨病显像并观察肿瘤临床疗效的价值.病人和方法:73例(女25,男48,年龄10/12月～65岁)各种骨病患者,恶性42例,良性31例.静脉投药(~(99m)Tc-MIBI7.4mBq·kg~(-1)后,30～60分钟行全身及病灶局部显像.此后72小时行MDP骨扫描.仪器为带LEAP型准直器的γ相机.MIBI和MDP骨显像片由2名核医学医生进行双盲判读.患侧/     

急性心肌梗塞病人治疗前后的~(99m)Tc-MIBI心肌灌注显像结果变化

用三次~(99m)Tc-MIBI心肌灌注显像观察了25例急性心肌梗塞病人治疗前后的动态改变.每次显像用740～1110MBq静脉注射,注射后1～6小时做SPECT显像.计算左室心肌灌注缺损范围占整个左室的百分比表示心肌缺血严重程度.第一次在入院时诊断后注射,相当胸痛开始后84～540分钟,在开始治疗前.急性心肌梗塞的主要治疗方法有组织血浆素原激活剂,链激酶和经皮冠状动脉扩张成形术等;第二次显像在入院后18～48小时,在X线冠状动脉造影和左室造影之前;第三次在入院后6～14天,即出院前进行.     

~(99m)Tc-MIBI SPECT心肌灌注显像评价右心室灌注的效果

右心室供血减少在临床上较难评价,右室梗塞常易漏诊.用~(99m)Tc-MIBI SPECT心肌灌注显像检查25例正常人(平均36岁)和25例可疑冠心病人(平均59岁).病人都作了~(201)Tl显像和X线冠状动脉造影,确诊11例有右冠状动脉狭窄超过50%,其中3例有下壁心肌梗塞史.~(99m)Tc-MIBI运动和静息显像分两天进行,注射剂量555MBq,作45°右前斜位到45°左后斜位的180°SPECT显像,用电子计算机掩盖左室后,用肉眼观察右室灌注情况,并加用每隔6mm的右室横轴切面作靶心图(bull's-eye)行客观分析.根据~(99m)Tc-MIBI右室显像,在11例右冠状动脉     

^99mTC标记药物进行心肌显像的最新进展

~(99m)Tc标记异腈类化合物,特别是~(99m)Tc-MIBI,除无再分布外,具有与~(201)Tl相似的基本特性,而且,~(99m)Tc-MIBI心肌显像可行首次通过及门电路心肌显像,能获得比~(201)Tl更好的SRECT显像。     

~(99m)Tc-MIBI运动加静态心肌灌注断层显像的初步临床应用

本文报告60例运动+静态心肌灌注断层显像,其中冠心病44例,心肌梗塞16例,并与心电图作了对比,结果表明,~(99m)Tc-MIBI心肌灌注断层显像对缺血性心脏病诊断的灵敏度为86.6％,高于ECG(68.3％),差异有非常显著意义(P<0.01),同时用靶心图对异常52例病人作了定量分析,在冠心病心肌缺血及梗塞定位诊断和鉴别诊断中具有与~(201)TL相似的灵敏性及特异性,而且心/肝比值高,图像质量佳,值得临床大力推广。     

~(99m)Tc-MIBI静息与~(201)Tl静息-再分布SPECT检测心肌梗塞患者心肌存活的比较

~(201)Tl采用两次注射法可改善对心肌缺血的诊断。作为心肌灌注显像剂的~(99m)Tc-MIBI是否也为心肌存活的显像剂则意见不一,也没有直接和~(201)Tl对比,本实验的目的是确定两种示踪剂在评价陈旧性心肌梗塞病人心肌存活中的     

~(99m)Tc-MIBI SPECT显像对心肌缺血定位的诊断效果

作者给32例患心绞痛的可疑冠心病人作了~(99m)Tc-MIBI SPECT心肌灌注显像,并与冠状动脉造影内径狭窄超过50%的部位作了比较.结果表明,这种SPECT图像比~(201)Tl图像质量好,灌注缺损边界清楚,小的缺损也能看清.尽管这样,每个部位的具体灌注情况评价可分为正常,可疑(possible),很可能是(probable)和肯定的(definife)灌注缺损.采取不同的诊断指标,心肌缺血的诊断敏感性和特异性就有变异.从本组资料来看,适当扣除本底,用很可能是灌注缺损作诊断指标,可得到敏感性为78%,特异性为100%的最佳效果.     

硝酸甘油介入99Tcm-MIBI SPECT心肌显像对PTCA决策的影响

目的评价硝酸甘油(NTG)介入99Tcm-甲氧基异丁基异腈(MIBI) SPECT心肌显像对心肌梗死患者行经皮冠状动脉腔内成形术(PTCA)决策的影响.方法 51例心肌梗死患者PTCA前1周内行99Tcm-MIBI静息和NTG介入心肌显像,术后2～3个月内复查静息心肌显像,并进行对比分析.结果 51例患者共141个心肌灌注异常节段,其中术后74个节段心肌血流灌注改善,治疗有效率为52.48%.术前NTG介入显像表现为可逆性缺损79个节段,术后84.81%(67个)节段心肌灌注改善,其中有明显填充的58个节段,术后全部灌注改善.NTG介入显像表现为不可逆性缺损的62个节段,有11.29 %(7个)节段术后心肌灌注改善.NTG介入显像检测心肌存活的准确性为86.52%.结论 NTG介入99Tcm-MIBI SPECT心肌显像对患者行PTCA起重要的决策作用.     

高血压病心肌灌注及硝酸甘油介入显像与室性心律失常关系的研究

目的　探讨高血压病心肌显像异常的临床意义及与心律失常的关系。方法　对 88例高血压患者行99Tcm 甲氧基异丁基异腈心肌灌注断层显像 ,对其中 5 7例显像异常者再行硝酸甘油介入心肌显像。所有患者均行Holter检查 ,冠状动脉造影 31例。结果　运动和静息显像后仍有 6 4 8%患者灌注减低 ,6 0 2 %的灌注减低节段硝酸甘油介入显示有填充或不完全填充 ,提示合并冠心病。多因素逐步回归分析表明 ,室性心律失常与心肌灌注减低的程度及左室肥厚 (LVH)呈线性回归关系。结论　心肌灌注断层显像及硝酸甘油介入心肌显像能反映高血压患者是否合并冠心病 ,并与其他高血压性病理改变所致的灌注减低相区别。高血压合并冠心病及LVH是心律失常的重要病理基础。     

双核素心肌显像检测存活心肌的对比研究

目的 对比多巴酚丁胺负荷201Tl/静息99Tcm-甲氧基异丁基异腈(MIBI)双核素同步心肌断层显像及多巴酚丁胺负荷-再分布/再注射201Tl心肌断层显像法检测存活心肌的作用.方法 对160例临床怀疑有冠心病的患者予静息状态下静脉注射740 MBq99Tcm-MIBI,休息15 min后进行多巴酚丁胺负荷试验,在达到终止指标时静脉注射111 MSq201TICI.注射后观察5-lO min,分别行早期(10 min)、延迟(3 h)99Tcm-MIBI和201Tl双核素同步心肌断层显像.对早期负荷201Tl图像发现放射性缺损,延迟再分布201Tl和静息99Tcm-MIBI图像未见放射性填充的患者再注射37 MBq201TICI,30min后行再注射心肌灌注显像.负荷枷201Tl图像示放射性缺损,静息99Tcm-MIBI、再分布201Tl及再注射201Tl图像中发现任何一种放射性填充者均为存活心肌.断层显像后2周内全部患者进行了冠状动脉造影.采用SAS 6.12软件进行x2检验.结果 (1) 160例患者冠状动脉造影均发现冠状动脉狭窄.其中单支病变76例、双支病变5l例、三支病变33例.(2)152例多巴酚丁胺负荷201Tl图像发现放射性缺损的患者中,63例201Tl再分布和静息99Tcm-MIBI图像均发现放射性填充,5例201Tl再分布发现放射性填充而静息99Tcm-MIBI图像未见放射性填充,9例静息99Tcm-MIBI图像发现放射性填充而2001Tl再分布未见放射性填允,75例201Tl再分布和静息99Tcm-MIBI图像均未发现放射性填充,负荷201Tl-延迟再分布显像(66.0%,68/103)和负荷201Tl/静息99Tcm-MIBI显像(69.9%,72/103)鉴别存活心肌的灵敏度差异无统计学意义(x2=O.36,P>0.05).(3)75例201Tl再分布和静息99Tcm-MIBI图像均未发现放射性填充患者中,再注射201Tl显像后有26例放射性填充,再注射201Tl显像较单纯201Tl再分布或静息99Tcm-MIBI显像多检测出34.7%(26/75)患者有存活心肌.(4)8例多巴酚丁胺负荷201Tl、201Tl再分布图像和静息99Tcm-MIBI图像均未发现放射性稀疏,为假阴性,其中3例为三支冠状动脉病变,1例为双支冠状动脉病变(狭窄分别为90%及60%),3例为单支冠状动脉病变(狭窄<75%2例,85%1例),1例冠状动脉闭塞后有充分的侧枝循环.结论 多巴酚丁胺负荷-再分布/再注射201Tl心肌断层显像鉴别存活心肌优于多巴酚丁胺负荷201Tl/静息99Tcm-MIBI双核素同步心肌断层显像,是一种有效、无创的鉴别存活心肌的方法.     

99mTc-MIBI myocardial perfusion imaging in myocarditis

Myocardial perfusion imaging with technetium-99m-labelled methoxyisobutyl isonitrile single photon emission computed tomography (99mTc-MIBI SPECT) has proven to be an important clinical procedure in assessing the severity of myocardial ischaemia. The uptake and clearance of 99mTc-MIBI by the myocardium is affected by cell viability and membrane integrity. Consequently, infectious diseases, such as myocarditis, may also affect myocardial perfusion by inducing local inflammation and necrosis. We compared 99mTc-MIBI myocardial perfusion imaging with other heart monitoring methods in order to assess its value in the diagnosis of children with Coxsackie viral myocarditis. We examined 46 patients (age, 3-12 years) with Coxsackie viral myocarditis using 99mTc-MIBI myocardial perfusion imaging and compared the perfusion data with myocardial enzymes, electrocardiographic findings and echocardiography. Regions of hypoperfusion were found in all 46 patients. Seventeen patients (37%) showed two or more areas of diminished perfusion. Myocardial hypoperfusion was mild-to-moderate (<30%) in 33 (72%) patients and severe (>30%) in 13 (28%) patients. Characteristic creatine-kinase isoenzyme (CK-MB) increases, ST-T segment changes and diminished heart function were significantly correlated with reduced myocardial perfusion (all comparisons P<0.05). The results of this study suggest that the presence of myocardial uptake of 99mTc-MIBI may be a marker of myocardial inflammation and necrosis. All 46 patients with Coxsackie viral myocarditis showed a certain degree of reduced perfusion. When the perfusion findings were compared with other parameters, it was shown that myocardial enzyme levels, ST-T segment changes and left ventricular function correlated well with the 99mTc-MIBI-established perfusion defect severity. 99mTc-MIBI SPECT imaging is therefore helpful in providing additional diagnostic information in patients with Coxsackie viral myocarditis.     

Effects of diltiazem on myocardial perfusion abnormalities during exercise in patients with hypertrophic cardiomyopathy

The effect of diltiazem on myocardial ischemia in patients with hypertrophic cardiomyopathy (HCM) was evaluated by exercise myocardial²⁰¹Tl single photon emission computed tomography (SPECT). Exercise myocardial SPECT was performed before and 8 weeks after oral administration of diltiazem (180 mg/day) in 20 patients with HCM who showed transient perfusion defects on exercise myocardial²⁰¹Tl SPECT under control conditions. SPECT images were divided into 17 segments. The²⁰¹Tl perfusion defects were visually scored and evaluated as the defect score. The transient dilation index was calculated as an index of subendocardial ischemia. Improvement of the defect score was demonstrated in 15 patients after the administration of diltiazem. The mean defect score decreased significantly from 9.90± 5.17 to 5.50±4.89 (p < 0.0001). Although 16 of 20 patients showed an abnormal transient dilation index before diltiazem treatment, 16 showed improvement and 13 of these normalized after diltiazem therapy. The mean transient dilation index decreased from 1.16 + 0.10 to 1.02 ± 0.09 (p < 0.0001). In conclusion, diltiazem prevents or diminishes myocardial ischemia in patients with HCM.     

Prognostic value of combined assessment of regional left ventricular function and myocardial perfusion by dobutamine and rest gated SPECT in patients with uncomplicated acute myocardial infarction.

Gated SPECT allows combined assessment of regional myocardial perfusion and left ventricular function. The aim of this study was to address the prognostic value of gated SPECT performed during dobutamine stress testing and during rest on patients with acute myocardial infarction treated with thrombolysis. METHODS: Eighty-eight consecutive patients with uncomplicated acute myocardial infarction who underwent predischarge (3-7 d after admission) dobutamine (5-40 microg/kg of body weight per minute in 3-min dose increments) and rest gated (99m)Tc-sestamibi SPECT were followed for a mean of 48 mo (range, 4-64 mo). RESULTS: Eighteen cardiac events (8 cardiac deaths and 10 nonfatal myocardial infarctions) occurred. Ischemia at dobutamine SPECT imaging (summed difference score or=>or= 1) was present in 60% of the patients. In patients without ischemia, there was a lower event rate (11%), compared with patients with mild ischemia (18%) and moderate-to-severe ischemia (40%) (P < 0.05). Patients with events showed also a higher summed difference score, compared with patients without events (2.3 +/- 1.6 vs. 1.3 +/- 1.6, P < 0.05). Independent predictors of events were the number of segments with preserved (99m)Tc-sestamibi uptake at rest and the number of akinetic or dyskinetic segments with preserved (99m)Tc-sestamibi uptake and preserved wall thickening (global chi(2) of the model, 13.6; P < 0.01). The assessment of the incremental prognostic value of variables added sequentially showed that the addition of the summed difference score added information to perfusion status at rest (P < 0.05). Combined assessment of regional myocardial perfusion and left ventricular function at rest further improved the model (P < 0.05). CONCLUSION: The present study indicated that predischarge (99m)Tc-sestamibi gated SPECT gives prognostic information on patients recovering from acute myocardial infarction. Patients with preserved systolic wall thickening should be regarded as a high-risk subgroup, requiring closer follow-up for appropriate treatment.     

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.     

Clinical significance of diastolic function as an indicator of myocardial ischemia assessed by 16-frame gated myocardial perfusion SPECT

Objective  Studies have suggested that ischemia-induced diastolic dysfunction persists longer than systolic dysfunction. We examined whether global left ventricular (LV) diastolic function during stress testing assessed by 16-frame gated myocardial perfusion single-photon emission computed tomography (SPECT) is useful as an indicator of myocardial ischemia. Methods  Thirty-nine patients underwent 16-frame technetium-99m (Tc-99m) quantitative gated SPECT (QGS), including treadmill exercise testing for suspected ischemic heart disease. Diastolic parameters of the first-third filling fraction (1/3FF), and the peak filling rate (PFR) were calculated by a time-volume curve from the QGS data. Results  The patients were divided into four groups, namely, IS, NL, DN, and DD, on the basis of tracer accumulation and the LV ejection fraction (LVEF) at rest. In the IS group (reversible tracer uptake reduction suggesting ischemia; n = 11), LVEF, 1/3FF, and PFR after stress were significantly lower than those at rest, whereas in the NL group (normal perfusion; n = 10) and DN group (fixed tracer uptake reduction with normal systolic function; EF ≥ 60% at rest; n = 10), LVEF, 1/3FF, and PFR after stress did not differ from those at rest. However, in the DD group (fixed tracer uptake reduction with cardiac dysfunction; EF < 60%, average 47.1%; n = 8), LVEF, 1/3FF, and PFR were significantly altered after stress. Conclusions  Altered global LV diastolic function during stress assessed by 16-frame gated myocardial perfusion SPECT is useful for the detection of myocardial ischemia. However, similar findings are observed in patients with cardiac dysfunction but without detectable ischemia. Our findings do suggest that tests should be performed with caution to determine whether ischemia exists on the basis of altered global LV function after stress in patients with cardiac dysfunction.     

心肌灌注断层显像与运动心电图ST段移位检测心肌缺血部位比较

目的　探讨运动心肌灌注断层显像与运动心电图ST段移位检测心肌缺血部位的一致性。方法　心肌灌注异常和ST段移位患者 3 0 2例 ,将ST段移位所在心肌部位与灌注异常部位进行相关性比较。结果　 40例ST段抬高的患者常有心绞痛史 ,并且易为运动诱发 ,运动持续时间较短(P <0 .0 5 )。ST段压低的部位与灌注异常的部位之间存在弱一致性 (Κ =0 .3 6,P <0 .0 1) ;左前降支(LAD)支配节段的灌注异常最常伴有前壁ST段压低 (χ2 =60 6.5 ,P <0 .0 5 ) ;ST段抬高与心肌灌注异常在病变定位上完全一致 (Κ =1.0 0 ,P <0 .0 1)。结论　ST段压低与灌注异常的定位一致性差 ,而ST段抬高则与灌注异常定位显著一致。     

MRI detection of myocardial perfusion defects due to coronary artery stenosis with MS-325

PURPOSE: To assess the value of an intravascular, albumin-targeted contrast agent, MS-325, in visualizing myocardial ischemia with magnetic resonance imaging (MRI). MATERIALS and METHODS: Left anterior descending coronary artery (LAD) stenosis was created in 19 pigs using a closed-chest modified angioplasty technique. Myocardial ischemia was detected by first-pass, contrast-enhanced MRI at peak dipyridamole stress and was compared to Technetium-99m (Tc-99m) sestamibi single photon emission computed tomography (SPECT). Regional coronary blood flow was determined using microspheres. RESULTS: Inducible myocardial ischemia with >40% reduction in stress myocardial blood flow was created in eight animals. An MRI defect, classified as > or=75% reduction in peak myocardial signal intensity in the affected territory, was detected in 92.3% of these animals. In the presence of mild coronary stenosis, there was uniform enhancement with MRI and tracer uptake by SPECT. Concordance of MRI and SPECT for detecting perfusion defects was 85%. CONCLUSION: The pattern of prolonged and persistent MR hypoenhancement of the ischemic myocardial bed using MS-325, which is retained primarily in the vascular bed due to its albumin-binding properties, facilitates the detection of myocardial perfusion defects.     

Prognostic value of myocardial ischemia in patients with uncomplicated acute myocardial infarction: direct comparison of stress echocardiography and myocardial perfusion imaging.

This study directly compared the prognostic value of predischarge dobutamine stress echocardiography (DSE) and dobutamine myocardial SPECT perfusion imaging in patients with prior myocardial infarction. METHODS: The study population consisted of 146 consecutive patients who underwent predischarge DSE and SPECT with (99m)Tc-sestamibi after a first acute uncomplicated myocardial infarction treated with thrombolysis. Fifty patients who underwent revascularization within 90 d from the imaging studies were excluded. Cardiac death and nonfatal myocardial infarction were considered events. Follow-up was 98% complete in a mean period of 44 +/- 19 mo. RESULTS: Myocardial ischemia was detectable in 55 (58%) patients at SPECT and in 63 (67%) patients at DSE. Concordance between SPECT and DSE in detecting ischemia was observed in 68 (72%) of the 94 patients (kappa value, 0.41). During the follow-up, there were 20 cardiac events (9 deaths and 11 nonfatal myocardial infarctions). Ischemia at SPECT was a significant predictor of events (hazards ratio = 4.8; 95% confidence interval, 1.4-16.3; P < 0.01). However, ischemia at DSE (biphasic or worsening patterns) was not associated with events, whereas biphasic pattern alone was associated with a poor outcome compared with direct worsening (P < 0.05). Finally, at Cox multivariate analysis, ischemia at SPECT but not biphasic pattern at DSE was a significant independent predictor of events (P < 0.01). CONCLUSION: These results indicate that, after uncomplicated myocardial infarction, ischemia at SPECT is associated with an increased risk of cardiac events at long-term follow-up. However, ischemia at DSE was unable to stratify patients after myocardial infarction.