硝酸甘油介入99mTc-MIBI心肌断层显像评估存活心肌

目的:探讨含服硝酸甘油介入99mTc-MIBI心肌断层显像在判断心肌存活中的价值.方法:12例心肌梗死患者先行静息99mTc-MIBI心肌断层显像,48小时后在静脉注射99mTc-MIBI前5分钟舌下含服硝酸甘油0.5mg,然后再行静息心肌断层显像.结果:12例心肌梗死患者静息心肌断层显像有68个节段放射性分布异常,服硝酸甘油介入后26个节段灌注改善;42个节段无变化或有异常加重.结论:含服硝酸甘油介入99mTc-MIBI心肌断层显像对判断心肌存活有一定的临床价值,且方法简便易行,安全可靠.     

冠状动脉介入治疗后缺血心肌恢复时间观察

目的：观察分析冠状动脉介入治疗（PCI）术后7～14天、3个月运动／静息99mTc-MIBI心肌灌注显像，评估PCI术后缺血心肌完全恢复时间。方法：将冠心病不稳定心绞痛42例PCI术后7～14天、3个月分别行运动／静息99mTc—MIBI心肌灌注显像，并进行比较分析。结果：PCI术后7～14天运动／静息99mTc—MIBI心肌灌注显像比较，差异显著（P〈0．01）；而术后3个月运动／静息99mTc—MIBI心肌灌注显像比较，差异不显著（P〉0．05）。结论：PCI术后7～14天仍有部分缺血心肌未完全恢复血流灌注，而3个月后缺血心肌完全恢复血流灌注。运动／静息99mTc—MIBI心肌灌注显像是评估心肌血流灌注的有效方法。     

静脉硝酸甘油介入前后心肌显像判断存活心肌

笔者对50例冠心病患者进行静息及微量静脉泵输入硝酸甘油(NTG)介入心肌显像，测算介入显像较静息显像有明显填充区域的面积及平均放射性计数，并以经皮冠状动脉腔内成形术(PTCA)及冠状动脉内支架植入术后静息心肌显像为标准进行比较，以探讨判断存活心肌的可靠方法。     

含服硝酸甘油介入^99mTc—MIBI心肌断层层像估测心肌存活的评价

为探讨含服硝酸甘油（ＮＴＧ）介入＾９９ｍＴｃ－甲氧基异丁腈（ＭＩＢＩ）心肌肌显像在心肌存活估测中的价值，对１６例心肌梗塞患者先行常规静态态＾９９ｍＴｃ－ＭＩＢＩ心肌断层显像，４８小时后在静脉放射性药物前５分钟舌下含服ＮＴＧ０．６ｍｇ，然后再行服药静息态心肌断层显像，冠状动脉旁路移植术或经皮穿刺腔内冠状动脉成形术后３个月重复静息态心肌显像并进去对比分析。结果：１６例患者静息态心肌断层显像有１１３个节     

大剂量硝酸甘油介入~(99m)Tc-MIBI心肌SPECT判定存活心肌的研究

目的：探讨大剂量硝酸甘油介入（大剂量硝充法）99mTc-MIBI心肌SPECT对存活心肌判定的价值。材料和方法：对44例大剂量硝充组和31例小剂量硝充组的心肌梗塞患者均行静息和硝充法心肌显像。采用9节段评分法对两次显像进行了比较。其中两组中分别有18例和17例于冠脉血管再通术（PTCA或CABG）后半年内再次复查了静息心肌显像并与术前比较。结果：大剂量硝充组静息心肌显像灌注异常节段为154个，硝充后有77个节段呈现了再分布，总再分布率为50．0％（77／154）；小剂量硝充组静息心肌显像灌注异常节段为110个，硝充后有35个节段呈现了再分布，总再分布率为31．8％（35／110）。大剂量和小剂量组中18例和17例PTCA和CABG患者术后静息心肌显像与硝充法心肌显像比较阳性符合率分别为85．7％和68．8％．预测准确率为对71．9％和50．9％。结论：大剂量硝酸甘油介入99Tc-MIBI心肌SPECT具有较高的存活心肌检出率和预测准确性。     

脂质体携载前列地尔介入心肌灌注显像评价心肌梗死患者心肌活性

目的对比分析脂质体携载前列地尔（Lipo—PGE1）与硝酸异山梨酯（ISDN）介入^99Tc^m-甲氧基异丁基异腈（MIBI）心肌灌注显像检测梗死节段心肌活性的差异。方法32例急性或陈旧性心肌梗死患者分别行静息、ISDN介入及Lipo—PGE1介入心肌灌注显像；将左心室划分为16个节段，半定量分析3种心肌灌注显像图。结果静息心肌灌注显像时共有216个心肌节段（42．2％）灌注异常；ISDN介入心肌显像时共有178个节段（34．8％）灌注异常，ISDN介入后89个节段（41．2％，89／216）放射性摄取改善；Lipo—PGE1介入心肌显像时共有184个节段（35．9％）灌注异常，Lipo—PGE1介入后81个节段（37．5％，81／216）放射性摄取改善。2种介入心肌显像诊断符合率为89．8％。静息显像心肌放射性摄取得分为（15．3±3．3）分，ISDN介入后减少为（10．5±1．4）分（P〈0．01），Lipo—PGE1介入后减少为（10．7±1．6）分（P〈0．01）。结论与ISDN介入心肌灌注显像一样，Lipo—PGE1介入心肌灌注显像可提高梗死节段存活心肌的检出率，且2种介入心肌显像具有相似的灵敏度。     

99mTc-MIBI硝酸甘油介入心肌显像预测PTCA治疗效果

目的 :预测经皮腔内冠状动脉成形术 (PTCA)的治疗效果。材料和方法 :2 7例患者在PTCA治疗前后分别进行静态和硝酸甘油 (NTG)介入99mTc MIBI心肌显像研究。结果 :PTCA治疗前 ,静态显像 83个稀疏或明显稀疏节段中 ,NTG介入后有 45个变为正常 ,其余大部分节段99mTc MIBI摄取量不同程度增加 ,静态 13个缺损节段中有 4个缺损范围缩小 ;PT CA治疗后 ,静态显像与PTCA治疗前NTG介入显像结果基本一致 ,NTG介入显像 ,又有 13个分布稀疏的节段变为正常。结论 :NTG介入99mTc MIBI心肌显像可以预测PTCA治疗效果 ;PTCA治疗后NTG介入显像有助于了解存活心肌状况。     

核素显像识别存活心肌的临床应用进展

存活心肌的判断对冠心病患者治疗方案的选择及预后十分重要。^201Tl再注射法、硝酸甘油介入的静息^99Tc^m-sestamibi法增强了心肌灌注核素体层显像对存活心肌的检测能力，门控SPECT技术能在评估心肌灌注的同时计算LVEF(左心室射血分数)、局部室壁运动和局部室壁增厚率，具有符合线路的SPECT可以进行心肌代谢显像及灌注显像，其对存活心肌的检测能力可能接近于PET，而检查费用可大大降低。     

核素显像识别存活心肌的临床应用进展

存活心肌的判断对冠心病患者治疗方案的选择及预后十分重要。201Tl再注射法、硝酸甘油介入的静息99Tcm-sestamibi法增强了心肌灌注核素体层显像对存活心肌的检测能力,门控SPECT技术能在评估心肌灌注的同时计算LVEF(左心室射血分数)、局部室壁运动和局部室壁增厚率,具有符合线路的SPECT可以进行心肌代谢显像及灌注显像,其对存活心肌的检测能力可能接近于PET,而检查费用可大大降低。     

~(99m)TC—MIBI心肌断层显像对心肌炎的诊断意义

本文用~(99m)TC—MIBI心肌显像对10例正常人,25例心肌炎病人的心肌断层、靶心图半定量分析结果进行了探讨,认为心肌显像对心肌炎的诊断有较高的灵敏度,阳性率达88％。心肌炎病人的图像特点为弥漫性或局限性“花斑”样放射性减低。运动试验与静息时图像大致相同,放射性减低程度无明显变化。心肌炎病人的半定量分析示,与正常人图像相比,其放射性减低约1～3个色阶。故~(99m)TC—MIBI心肌断层显像可为心肌炎的病人提供心肌受损的范围、程度。为临床治疗及预后的估价提供有意义的参考价值。     

应用门控SPECT测量左心室功能的方法学研究

目的：试用门控心肌显像测定左室功能并与心血池显像结果比较。材料和方法：61例受检者进行了Tc-99m—MIBI门控心肌显像及心血池显像．结果：门控断层心肌显像的短轴中间部左室功能结果与平衡法心血池显像有良好的相关性(r=0．82）。结论：门控心肌断层显像测定的左室功能结果方法简便可靠．能同时反映心肌直流及左室功能。     

Comparison of Technetium-99m-MIBI imaging with MRI for detection of spine involvement in patients with multiple myeloma

BACKGROUND: Recently, radiopharmaceutical scanning with Tc-99m-MIBI was reported to depict areas with active bone disease in multiple myeloma (MM) with both high sensitivity and specificity. This observation was explained by the uptake of Tc-99m-MIBI by neoplastic cells. The present investigation evaluates whether Tc-99m-MIBI imaging and magnetic resonance imaging (MRI) perform equally well in detecting myelomatous bone marrow lesions. METHODS: In 21 patients with MM, MRIs of the vertebral region TH12 to S1 and whole body scans with Tc-99m-MIBI were done. RESULTS: Tc-99m-MIBI scanning missed bone marrow infiltration in 43 of 87 vertebrae (50.5%) in which MRI showed neoplastic bone marrow involvement. In patients with disease stage I+II, Tc-99m-MIBI scanning was negative in all of 24 vertebrae infiltrated according to MRI. In patients with disease stage III, Tc-99m-MIBI scanning detected 44 of 63 (70%) vertebrae involved by neoplastic disease. CONCLUSION: Tc-99m-MIBI scanning underestimated the extent of myelomatous bone marrow infiltration in the spine, especially in patients with low disease stage.     

Tc-99m tetrofosmin tomography after nitrate administration in patients with ischemic left ventricular dysfunction: Relation to metabolic imaging by PET

BACKGROUND: In patients with ischemic left ventricular (LV) dysfunction, myocardial perfusion imaging after nitrate administration may improve the identification of dysfunctional but viable myocardium. This study was designed to assess the relationship between tetrofosmin uptake after nitrate administration and metabolic activity as assessed by positron emission tomography (PET) in patients with ischemic LV dysfunction. METHODS AND RESULTS: Thirty-six patients with chronic myocardial infarction and LV dysfunction (ejection fraction, 35% +/- 6%) underwent resting technetium 99m tetrofosmin single photon emission computed tomography (SPECT) imaging under control conditions (baseline) and after sublingual administration of 10 mg isosorbide dinitrate. Within 1 week, all patients underwent metabolic PET imaging with fluorine 18-fluorodeoxyglucose. Tetrofosmin uptake and metabolic activity were measured in 13 segments/patient. Regional LV function was assessed in corresponding segments by echocardiography. On baseline tetrofosmin imaging, 53 (40%) of the 131 akinetic or dyskinetic segments had reduced (<55% of peak activity) tracer uptake. Of these segments, 14 (26%) showed enhanced tetrofosmin uptake after nitrate administration (>/=10% vs baseline) and the remaining 38 (74%) did not change. The sensitivity and specificity of baseline tetrofosmin SPECT for detecting preserved metabolic activity were 69% and 86%, respectively. After nitrate administration, the sensitivity was higher (81%, P <.05 vs baseline) whereas the specificity was not different (86%, P = not significant). Concordance between tetrofosmin SPECT and PET in differentiating viable and necrotic myocardium was observed in 94 (72%) of the 131 akinetic or dyskinetic segments at baseline (kappa = 0.35) and in 108 segments (82%) after nitrate administration (kappa = 0.53). CONCLUSIONS: After nitrate administration, tetrofosmin uptake in dysfunctional segments correlated with metabolic activity as assessed by fluorodeoxyglucose PET imaging better than baseline. Thus tetrofosmin SPECT after nitrate administration may improve the identification of ischemic but still viable myocardium in patients with chronic ischemic LV dysfunction.     

Improved detection of myocardial perfusion reversibility by rest-nitroglycerin Tc-99m-MIBI: Comparison with Tl-201 reinjection

BACKGROUND: The role of nitroglycerin (NTG) in Tc-99m-methoxyisobutil isonitrile (MIBI) studies to improve the assessment of myocardial viability in patients with coronary artery disease and its comparison with TI-201 reinjection has not yet been clarified. This study aimed to test whether sublingual administration of NTG could improve the capability of Tc-99m-MIBI to detect reversibility in exercise-induced perfusion defects and to compare it with the TI-201 stress-redistribution-reinjection protocol. METHODS AND RESULTS: Thirty-eight patients (33 men, 5 women; mean age 49.3 +/- 8.2 years with previous myocardial infarction [mean evolution 7.1 +/- 3.9 months]) underwent exercise, redistribution, and reinjection TI-201 imaging, as well as exercise, rest, and NTG MIBI myocardial scintigraphy (3-day protocol). A total of 494 myocardial segments were assessed by quantitative analysis. Of the 136 myocardial segments with fixed defects on exercise-rest sestamibi imaging, 109 (80%) did not change after NTG MIBI study, and 27 (20%) demonstrated enhanced uptake. In the 140 myocardial segments with fixed defects on exercise-redistribution thallium imaging, 112 (80%) did not improve after TI-201 reinjection study, and 28 (20%) showed increased activity. The observed agreement on reversibility detection between NTG MIBI and TI-201 reinjection, with the 210 segments with perfusion defects used for this analysis on both studies, was 78%, with a significant kappa = .56 +/- .07 SE. CONCLUSION: Our data suggest that the use of an NTG MIBI protocol results in an incremental improvement for detecting exercise-induced perfusion defect reversibility and achieves results similar to those from a TI-201 reinjection protocol.     

Nitrate administration increases blood flow in dysfunctional but viable myocardium, leading to improved assessment of myocardial viability: A PET study.

SPECT with 99mTc-labeled agents is better able to detect viability after nitrate administration. Nitrates induce vasodilation and may increase blood flow to severely hypoperfused but viable myocardium, thereby enhancing tracer delivery and improving the detection of viability. Quantitative data on the changes in blood flow are lacking in SPECT but can be provided by PET. The aim of the present study was to use PET to evaluate whether nitrate administration increases blood flow to chronically dysfunctional but viable myocardium. METHODS: 13N-Ammonia PET was used to quantitatively assess blood flow, and 18F-FDG PET was used as the gold standard to detect viable myocardium. Twenty-five patients with chronic ischemic left ventricular dysfunction underwent 13N-ammonia PET at rest and after nitrate administration. RESULTS: A significant increase in nitrate-enhanced blood flow was observed in viable segments (from 0.55 +/- 0.15 to 0.68 +/- 0.24 mL/min/g, P < 0.05). No statistically significant change in blood flow was observed in nonviable segments (0.60 +/- 0.20 vs. 0.55 +/- 0.18 mL/min/g). A ratio of at least 1.1 for nitrate-enhanced flow to resting flow allowed optimal detection of viable myocardium, yielding a sensitivity of 82% with a specificity of 100%. CONCLUSION: 13N-Ammonia PET showed a significant increase in nitrate-enhanced blood flow in viable myocardium, whereas blood flow remained unchanged after nitrate administration in nonviable myocardium. Nitrate use during myocardial perfusion imaging will lead to improved assessment of myocardial viability.     

Optimal pinhole techniques for preoperative localization with Tc-99m MIBI for primary hyperparathyroidism.

PURPOSE: Technetium-99m-labeled 2-methoxyisobutylisonitrile (Tc-99m MIBI) has been used extensively to localize parathyroid adenomas before operation. Imaging techniques vary widely, and the aim of this study was to determine the optimal time of delayed imaging and the value of routine correlative pertechnetate thyroid imaging. MATERIALS AND METHODS: In this study, preoperative parathyroid localization was performed using pinhole anterior and oblique images (15 minutes and 2 and 4 hours after injection) with correlative pertechnetate thyroid images. Ninety-seven patients underwent dual- or triple-phase Tc-99m MIBI imaging and correlative pertechnetate thyroid imaging before surgery. Two nuclear medicine physicians blinded to the surgical findings interpreted all available images and various Tc-99m MIBI image combinations at 15 minutes alone; 15 minutes and 2 hours, 15 minutes and 4 hours; and 15 minutes and 2 and 4 hours each with and without correlative pertechnetate thyroid imaging. RESULTS: Ninety parathyroid adenomas were detected in 86 patients. The optimal results were achieved with 15-minute and 2- and 4-hour Tc-99m-MIBI images, with correlative thyroid scans resulting in a sensitivity rate of 88%. Fifteen-minute and 2-hour Tc-99m-MIBI images and correlative thyroid scans and 15-minute and 4-hour Tc-99m MIBI images and correlative thyroid scans produced similar results (sensitivity rate, 86% and 83%, respectively; P = not significant). Compared with all Tc-99m MIBI image combinations alone, the addition of the routine correlative thyroid scan significantly improved sensitivity and also improved reporter confidence in 45% of studies. CONCLUSIONS: Of the pinhole techniques compared, 15-minute and 2-hour Tc-99m MIBI images with correlative thyroid scanning may be the preferred imaging protocol, because this yields results similar to imaging for as long as 4 hours after injection in a shorter, more logistically acceptable imaging time.     

Reproducibility of Tl-201 and Tc-99m sestamibi gated myocardial perfusion SPECT measurement of myocardial function

BACKGROUND: We compared the reproducibility of thallium 201 and technetium 99m sestamibi (MIBI) gated single photon emission computed tomography (SPECT) measurement of myocardial function using the Germano algorithm (J Nucl Med 1995;36:2138-47). METHODS AND RESULTS: Gated SPECT acquisition was repeated in the same position in 30 patients who received Tl-201 and in 26 who received Tc-99m-MIBI. The quantification of end-diastolic volume (EDV), end-systolic volume (ESV), and ejection fraction (EF) on Tl-201 and Tc-99m-MIBI gated SPECT was processed independently with Cedars-Sinai QGS (Quantitative Gated SPECT) software. The reproducibility of the measurement of ventricular function on Tl-201 gated SPECT was compared with that of Tc-99m-MIBI gated SPECT. Correlation between the 2 measurements for volumes and EF was excellent for the repeated gated SPECT studies of Tl-201 (r = 0.928 to 0.986, P <.05) and Tc-99m-MIBI (r = 0.979 to 0.997, P <.05). However, Bland-Altman analysis revealed the 95% limits of agreement (2 SDs) for volumes and EF were narrower by repeated Tc-99m-MIBI gated SPECT (EDV 14.1 mL, ESV 9.4 mL, EF 5.5%) than by repeated Tl-201 gated SPECT (EDV 24.1 mL, ESV 18.6 mL, EF 10.3%). The root-mean-square values of the coefficient of variation for volumes and EF were smaller by repeated Tc-99m-MIBI gated SPECT (EDV 2.1 mL, ESV 2.7 mL, EF 2.3%) than by repeated Tl-201 gated SPECT (EDV 3.2 mL, ESV 3.5 mL, EF 5.2%). CONCLUSIONS: QGS provides an excellent correlation between repeated gated SPECT with Tl-201 and Tc-99m-MIBI. However, Tc-99m-MIBI provides more reproducible volumes and EF than Tl-201. Tc-99m-MIBI gated SPECT is the preferable method for the clinical monitoring of ventricular function.     

Comparison of the prognostic value of SPECT after nitrate administration and metabolic imaging by PET in patients with ischaemic left ventricular dysfunction

Purpose We compared the prognostic value of ^99mTc-tetrofosmin single-photon emission computed tomography (SPECT) after nitrate administration and positron emission tomography (PET) with ¹⁸F-fluorodeoxyglucose (FDG) in patients with ischaemic left ventricular (LV) dysfunction. Methods Eighty-nine patients with previous myocardial infarction and LV dysfunction (LV ejection fraction 33 ± 10%) underwent ^99mTc-tetrofosmin SPECT under control conditions (baseline) and after sublingual administration of 10 mg of isosorbide dinitrate (nitrate). Within 1 week, all patients underwent PET imaging with ¹⁸F-FDG. Four patients were excluded because of inadequate FDG uptake caused by severe diabetes. Follow-up data were obtained by phone contact with patients and by review of hospital or physicians’ records. Cardiac death, myocardial infarction and late revascularisation for unstable angina were considered as events. Follow-up data were not available in three patients. Follow-up was 96% complete at a mean period of 29 ± 19 months. Results At baseline SPECT, 59 (72%) patients had evidence of viable myocardium, while 23 did not. Of these latter patients, 12 (52%) demonstrated viable myocardium after nitrate and 13 (56%) had preserved metabolic activity. Cardiac events (cardiac death, myocardial infarction and late revascularisation for unstable angina) occurred in 24 (29%) patients. Event-free survival was similar in patients with and patients without viable myocardium at baseline SPECT (p = 0.8). In contrast, event-free survival was lower in patients with viable myocardium at nitrate SPECT and PET compared to those without viable myocardium (both p<0.05). Conclusion In patients with ischaemic LV dysfunction, the prognostic value of SPECT imaging after nitrate is comparable to that of PET metabolic imaging.     

Reverse redistribution of Tc-99m-tetrofosmin in exercise myocardial SPECT in patients with hypertrophic cardiomyopathy

We examined the usefulness of Tc-99m-tetrofosmin in detecting exercise induced perfusion abnormalities in patients with hypertrophic cardiomyopathy (HCM) and to clarify time-related changes in myocardial distribution of Tc-99m-tetrofosmin after a single injection. We studied 44 consecutive patients with HCM by means of exercise/rest Tc-99m-tetrofosmin single photon emission computed tomography (SPECT). After injecting 370 MBq of Tc-99m-tetrofosmin at the peak exercise, the early SPECT imaging was performed at 30 min (EX-30) and the delayed imaging at 180 min (EX-180). Immediately after the delayed imaging, 740 MBq of Tc-99m-tetrofosmin was injected in the resting state, and the rest SPECT imaging was performed 30 min later. Exercise-induced regional perfusion defects and/or apparent reversible left ventricular cavity dilation were identified in 26 (68.2%) of the 44 patients. When EX-30 images and EX-180 images were compared, reverse redistribution was confirmed in 36 patients (81.8%). Reverse redistribution was detected most frequently in the septal portion of the anterior wall, followed by the septal portion of the posterior wall and the septum. Exercise/rest Tc-99m-tetrofosmin myocardial imaging was a useful method for assessing myocardial perfusion abnormalities in patients with HCM. Reverse redistribution was detected very frequently on early and delayed images of exercise. We assumed that reverse redistribution may reflect a retention disorder of Tc-99m-tetrofosmin caused by some metabolic dysfunction of myocytes.