硝酸甘油酯介入~(99m)Tc-MIBI心肌断层显像与多巴酚丁胺负荷超声心动图判定存活心肌的比较

为比较硝酸甘油酯（ＮＴＧ）介入９９ｍＴｃ甲氧基异丁基异腈（ＭＩＢＩ）心肌断层显像与小剂量多巴酚丁胺负荷超声心动图（ＤＳＥ）在判断急性心肌梗塞（ＡＭＩ）后病人存活心肌中的一致性，对３６例ＡＭＩ病人分别进行了ＮＴＧ介入９９ｍＴｃＭＩＢＩ心肌断层显像和小剂量（＜１０μｇ·ｋｇ－１·ｍｉｎ－１）的ＤＳＥ检查，所有检查均在病人入院后２～３周内完成。结果：在心肌静态显像示梗塞的１０９个节段中，ＮＴＧ显像４３个为存活节段，存活心肌检出率为３９％；在基础状态下超声心动图示梗塞的９４个节段中，ＤＳＥ检查３５个为存活节段，其存活心肌检出率为３７％，两者间差异无显著性（χ２＝０１０５，Ｐ＞００５）。在两法共同检出的９２个梗塞节段中，均存活的节段为２９个，均未存活的节段为４９个，两法的一致性为８４８％（７８／９２，Κ＝０６８）。因此，ＮＴＧ介入９９ｍＴｃＭＩＢＩ心肌断层显像与ＤＳＥ检查均为判断ＡＭＩ后病人存活心肌的安全、可靠的方法，两法具有良好的一致性。     

Comparison of exercise-rest-reinjection Tl-201 imaging and rest sublingual isosorbide dinitrate Tc-99m MIBI imaging for the assessment of myocardial viability

Purpose  Nitrate administration has been proposed to enhance the detection of myocardial viability when performing myocardial perfusion imaging. In this study, we aimed to compare Tl-201 exercise-rest-reinjection protocol with rest isosorbide dinitrate (ISDN)-Tc99m MIBI study in the same population examined for the myocardial viability. Methods  Twenty-six patients with coronary artery disease who had fixed segmental defects on exercise-rest-Tl-201 imaging were studied. All of them underwent Tl-201 reinjection study. Within 1 week of Tl-201 imaging, rest-Tc99m MIBI imaging was performed after sublingual 5 mg ISDN administration (2-day protocol). For each study, tomograms were divided into 20 segments based on three short-axis slices, one vertical long-axis representing the totality of the left ventricle and regional tracer uptake was quantitatively analyzed. Regional tracer uptake was evaluated in 20 myocardial segments for all patients. Viability was defined as presence of tracer uptake ≥50% of peak activity on each study. A total 520 myocardial segments were assessed by semi quantitative analysis. Result  On the baseline rest Tl-201 studies, 211 segments of the 520 segments that were analyzed had <50% of peak activity. Of these segments, 42 (20%) showed reversibility after reinjection Tl-201 imaging and 55 segments (27%) described as viable on the rest ISDN-Tc99m MIBI imaging. There was 89% concordance between the ISDN-Tc99m MIBI study and Tl-201 reinjection study regarding viable myocardial segments. Of the 23 segments with discordant results, 18 were irreversible on Tl-201 reinjection study, but showed ≥50% uptake on ISDN-Tc99m MIBI. Conclusion  Observation of good agreement between Tl-201 reinjection and ISDN-Tc99m MIBI study studies led us to suggest the use of ISDN enhanced imaging in the evaluation of myocardial viability.     

Tc-99m MIBI SPECT in the assessment of myocardial reperfusion after percutaneous transluminal coronary angioplasty.

Tc-99m MIBI SPECT was used to assess the early benefits of successful percutaneous transluminal coronary angioplasty (PTCA) in nine consecutive patients. SPECT stress studies were done by artificial cardiac pacing just prior to PTCA and 16-20 hours later, with perfusion images obtained 2-3 hours after pacing stress and Tc-99m MIBI injection. Angiographic restenosis was demonstrated in three patients at a later date, and all of these showed no significant improvement on the perfusion study after PTCA. All four patients asymptomatic at 7 months following PTCA had an average 15% improvement in segmental perfusion after the procedure. In two patients symptomatic after PTCA, one showed angiographic patency and had greater than 15% improvement in perfusion, while the second showed no scintigraphic improvement (no angiographic data obtained). This preliminary study suggests that Tc-99m MIBI is an important adjunct to angiography in estimating the amount of myocardium "at risk" before and after PTCA.     

含服硝酸甘油后99mTc-MIBI心肌显像与201Tl再注射显像检测存活心肌的比较

目的观察硝酸甘油介入后心肌显像（ＭＢＮ）在预测经皮冠状动脉成形术（ＰＴＣＡ）后心室壁活动改善中的准确性，并与２０１Ｔｌ再注射显像（ＴｌＲＲ）结果进行比较。方法３１例心肌梗塞患者在２周内分别进行２０１Ｔｌ静息及再注射显像、９９ｍＴｃ甲氧基异丁基异腈（ＭＩＢＩ）潘生丁介入及硝酸甘油介入心肌显像，将左心室心肌分成９个节段，应用周边剖面法定量分析左心室各节段放射性分布，并以左心室峰节段计数的百分率表达。结果在３１例患者共计１６２个异常节段中，ＭＢＮ及ＴｌＲＲ见有明确放射性摄取改善者分别为６１％及６４％（Ｐ＞００５）；以静息２０１Ｔｌ显像心肌各节段放射性分布值的高低分为４组，各组内ＭＢＮ及ＴｌＲＲ摄取值差异无显著性；在１３例完成显像后进行ＰＴＣＡ治疗的患者中，ＭＢＮ及ＴｌＲＲ对手术后心室壁活动改善的阳性预测率分别为８２％及７８％，阴性预测率分别为８８％及９０％，χ２检验两者差异无显著性。结论含服硝酸甘油介入９９ｍＴｃＭＩＢＩ心肌显像检测心肌梗塞区存活心肌具有与２０１Ｔｌ再注射显像相似的准确性，且方法简便实用，易于临床推广。     

Noninvasive assessment of coronary microvascular dysfunction using Tc-99m tetrofosmin SPECT in patients with acute myocardial infarction

BACKGROUND: We investigated whether technetium 99m tetrofosmin (TF) single photon emission computed tomography (SPECT) could predict coronary microvascular dysfunction in patients with acute myocardial infarction. METHODS AND RESULTS: We obtained the regional severity score index (TF-RSSI) using TF SPECT immediately after percutaneous coronary intervention in 25 patients with acute myocardial infarction. Using a Doppler guidewire, we evaluated the deceleration time of diastolic flow velocity (DDT) after percutaneous coronary intervention, and DDT of 600 milliseconds or less was suggested to be an indicator of coronary microvascular dysfunction. Moreover, the chronic regional wall motion score index (RWMSI) was obtained from echocardiography during the chronic phase. There was a good correlation between TF-RSSI and DDT (r = -0.68, P < .01). The optimal cutoff value of TF-RSSI to predict DDT of 600 milliseconds or less was defined as 1.9 or greater (sensitivity, 1.00; specificity, 0.71). The group with poor scintigraphic coronary microvascular function (TF-RSSI > or =1.9, n = 7) demonstrated a significantly shorter DDT (P = .0003), a lower frequency of early systolic retrograde flow (P = .0038), and greater chronic RWMSI (P = .0015) than the group with good scintigraphic coronary microvascular function (TF-RSSI <1.9, n = 15). CONCLUSIONS: Analysis of TF SPECT immediately after percutaneous coronary intervention in patients with acute myocardial infarction is a useful noninvasive method for evaluating coronary microvascular dysfunction.     

A trial for the quantification of regional myocardial blood flow with continuous infusion of Tc-99m MIBI and dynamic SPECT

We propose a new method to quantify regional myocardial blood flow (rMBF) by continuous infusion of Tc-99m MIBI and dynamic SPECT. METHODS: Five patients with old myocardial infarction were studied. During continuous infusion of MIBI (approximately 740 MBq) with a syringe pump in 10 min, dynamic SPECT scan was performed every minute and lasted 20 min after the start of infusion to identify myocardial uptake of MIBI. Input function was obtained from the radioactivity in the left ventricle (LV) in dynamic SPECT images. Spillover fraction between LV and myocardium (M) was corrected with phantom data. The influx constant (Ku) was calculated by Patlak plot graphical analysis, and compared with rMBF measured by PET (F) with N-13 ammonia based on Patlak plot analysis with correction for the extraction fraction. To correct the limited first-pass extraction of MIBI, linearization correction by means of the permeability-surface area (PS) product value was also applied. RESULTS: Spillover fractions of MIBI were 0.169+/-0.056 from LV to M, and 0.042+/-0.021 from M to LV. Ku was well correlated with F (Ku = 0.057 + 0.220F, r = 0.83, p < 0.01) and the slope and correlation were improved after linearizaiton (F(MIBI) = -0.131+0.858F, r = 0.94, p < 0.01). CONCLUSION: The proposed method has the potential to be a clinically feasible tool for quantitative measurement of rMBF.     

Tc-99m MIBI SPECT in prediction of prognosis in patients with small cell lung cancer

PURPOSE: The purpose of this study was to evaluate whether the degree of technetium-99m methoxyisobutylisonitrile (MIBI) uptake and its retention in delayed imaging in small cell lung cancer (SCLC) was correlated with the response to multiagent chemotherapy and to investigate if there was a relationship between the survival time of patients with SCLC and Tc-99m MIBI SPECT tumor uptake parameters at the time of diagnosis. METHODS: Between 1998 and by December 2004, 40 patients with SCLC were studied with Tc-99m MIBI SPECT at the time of diagnosis. The patients were classified by a follow-up CT as good responders (complete or partial remission) and poor responders (stable disease or progressive disease). Following i.v. administration of 740 MBq Tc-99m MIBI, SPECT imaging at 30 minutes (early) and 2 hours (delayed) was performed. Regions of interests were placed over the tumors and contralateral normal lung tissue on one transverse section. The uptake ratio of the lesion to that in the contralateral normal lung was obtained from early images (early ratio; ER) as well as delayed images (delayed ratio; DR). The retention index (RI%) was measured as: RI% = [(DR-ER)/ER] x 100. Tc-99m MIBI tumor uptake parameters were compared with chemotherapeutic response and survival time. RESULTS: Of 40 patients, 29 patients were good responders (72.5%) and 11 patients were poor responders (27.5%). RI% of Tc-99m MIBI SPECT in the group of good response was significantly higher than in that with poor response (p < 0.05). On the other hand, there was no significant difference between the two groups with respect to ER or DR values. Four of 40 patients were still alive with disease (10%). The patient survival time varied from 1 to 70 months (mean survival time = 12.9 +/- 13.4 months). There was no significant difference between the survival time of patients with respect to ER or DR of Tc-99m MIBI SPECT imaging. When median RI% was accepted as a cut-off value (-3.85%), patients with higher RI% values had a longer survival time (12 months) when compared with those with low RI% (8 months), p < 0.05. CONCLUSION: Our results suggest that Tc-99m MIBI SPECT could accurately predict the chemotherapy response in patients with SCLC. RI% of Tc-99m MIBI SPECT is recommended to differentiate patients with a poor response to chemotherapy and good responders, and RI% of Tc-99m MIBI SPECT appears as the only parameter that may be useful in predicting the survival of patients with SCLC.     

Dobutamine stress electrocardiography-gated Tc-99m tetrofosmin SPECT for detection of viable but dysfunctional myocardium

BACKGROUND. Technetium-99m-labeled myocardial perfusion tracers allow simultaneous assessment of myocardial perfusion and left ventricular function by electrocardiography-gated scan. This study was performed to determine whether dobutamine stress electrocardiography-gated tetrofosmin single photon emission computed tomography (SPECT) can identify viable (as defined by positron emission tomography [PET]) but dysfunctional myocardium with contractile reserve. METHODS AND RESULTS. Thirty-five patients with myocardial infarction underwent resting electrocardiography-gated SPECT and fluorodeoxyglucose (FDG) PET. The relative uptakes of tetrofosmin (%tetrofosmin) and FDG (%FDG) were calculated. Wall motion in 9 left ventricular segments was assessed at rest and during dobutamine stress on a 3-dimensional cine-mode display created with automatic left ventricular function analysis software. A total of 129 dysfunctional segments were analyzed. Forty-five (48.9%) of 92 segments with %tetrofosmin of 50% or greater and only 4 (10.8%) of 37 segments with %tetrofosmin less than 50% had contractile reserves (P <.0001). The sensitivity, specificity, and predictive accuracy of %tetrofosmin of 50% or greater for detecting %FDG of 50% or greater were 85.7%, 74%, and 82.9%, respectively. The incidence of the presence of contractile reserve rose with increasing magnitude of %FDG. The sensitivity, specificity, and predictive accuracy of the presence of contractile reserve for detecting %FDG of 50% or greater were 43.9%, 80.6%, and 52.7%, respectively. CONCLUSIONS. Dobutamine stress electrocardiography-gated SPECT can identify viable (as defined by PET) but dysfunctional myocardium with contractile reserve.     

Ectopic parathyroid adenoma with Tc-99m MIBI washout: role of SPECT

The authors present a case of a 71-year-old woman with clinical and biochemical features of primary hyperparathyroidism and a history of right pneumonectomy. An ultrasound scan did not demonstrate any abnormality. A planar Tc-99m methoxyisobutylisonitrile (Tc-99m MIBI) scan showed an area of minimally increased uptake within the right hemithorax. However, unlike most adenomas, this demonstrated washout similar to the thyroid at 90 minutes and 3 hours. Subsequent SPECT imaging clearly showed the lesion in the superior right hemithorax. A CT scan and angiogram confirmed the presence of this mass. After surgery, histology confirmed the diagnosis of a parathyroid adenoma. Postoperatively, the calcium and PTH levels returned to normal.     

Bone uptake of Tc-99m MIBI in patients with hyperparathyroidism

Objective

The study aimed to investigate the incidence of bone uptake of tracer on Tc-99m MIBI imaging and explore its influencing factors and significance for diagnosis of metabolic bone disease (MBD) in patients with hyperparathyroidism (HPT).

Methods

Seventy-nine consecutive patients with histopathologically confirmed HPT (63 primary and 16 secondary) who had preoperative Tc-99m MIBI imaging were retrospectively evaluated. Serum calcium (Ca), phosphorus (P), and intact parathyroid hormone (iPTH) were measured for all patients, and serum alkaline phosphatase (ALP) was measured for 62 patients. Of the 79 patients, 50 underwent bone mineral density (BMD) examination and 30 underwent bone scintigraphy. The incidence and characteristics of abnormal bone uptake of MIBI were recorded. Mann–Whitney test was performed to determine if serum iPTH, Ca, P, ALP, and BMD were different between the patients with and without MIBI bone uptake. Logistic regression analysis was used to analyze the factors that influence the bone uptake of MIBI. The concordance rate between Tc-99m MIBI imaging and bone scintigraphy in delineating MBD was calculated.

Results

Tc-99m MIBI imaging disclosed the abnormal bone uptake of tracer in 22 (27.8 %) patients. Of them, 19 showed diffusely increased activity in skeleton, 2 showed focal uptake in brown tumors, and one showed both above patterns. Patients with bone uptake MIBI had higher level of serum iPTH (Z = ?4.34, P < 0.001) and ALP (Z = ?3.50, P < 0.001) than those without bone uptake. Logistic regression analysis also showed that bone uptake of MIBI was correlated with serum iPTH (OR = 4.42, P < 0.001) and ALP (OR = 3.21, P = 0.002). Among the 30 patients that underwent bone scintigraphy, 76.7 % patients showed signs of MBD, and the concordance rate between Tc-99m MIBI imaging and bone scintigraphy was 60 % for detecting MBD.

Conclusions

Bone uptake of MIBI in patients with HPT is commonly related to a high level of iPTH and ALP; it probably reflects an active stage of MBD, and it should be monitored during the conventional Tc-99m MIBI scintigraphy.     

Focal pulmonary uptake during Tc-99m myocardial perfusion SPECT imaging

PURPOSE: To evaluate the incidence and origin of abnormal focal pulmonary uptake during myocardial perfusion SPECT imaging (MSPECT). METHODS: For evaluation of chest pain, 790 men and 581 women (mean age, 56 +/- 13 years) underwent MSPECT. All of them received adenosine for pharmacologic stress and Tc-99m tetrofosmin (TF, n = 817) or Tc-99m sestamibi (MIBI, n = 554) for myocardial perfusion imaging. RESULTS: Review of chest radiography with or without computed tomography revealed 111 (8.1%) focal pulmonary diseases. Among them, 38 (34.2%) showed focal pulmonary uptake (TF, 22; MIBI, 16); 27 (30.7%) of 88 showed previous pulmonary tuberculosis; 2 of 10 (20%) benign pulmonary nodules; 4 of 5 (80%) metastatic lung cancers; 2 of 4 (50%) primary lung cancers; and 3 of 4 (75%) pneumonias. No difference in uptake was noted for the two imaging agents. Intensity of uptake did not vary with origin of the uptake. Focal abnormal pulmonary uptake was found in 2.8% of patients undergoing MSPECT and in 34.2% of patients in whom radiological examinations showed regional pulmonary disease. In patients with abnormal pulmonary uptake on MSPECT, 16% had a malignant lesion, whereas 75% of patients with a pulmonary nodule shown on radiography and focal pulmonary uptake on MSPECT had a malignant lesion. CONCLUSIONS: Although the incidence of abnormal pulmonary uptake during MSPECT was very low, the incidence of malignant lesions in the patients with nodular pulmonary uptake was relatively high.     

核素心肌断层显像诊断瓣膜病人合并冠状动脉病变的价值

为了解瓣膜病患者是否合并冠状动脉病变，对６３例经临床确诊为瓣膜疾病的病人在外科手术前行＾９９ｍＴｃ－甲氧基异丁基异腈（ＭＩＢＩ）心肌断层显像，其中５５例做运动或药物负荷试验，８例单纯行静息心肌显像；２７例行冠状动脉造影；５７例行瓣膜外科手术。所有病人手术前、后均作超声心动图检查。结果：２７例心肌ＳＰＥＣＴ显像与冠状动脉造影结果对比，符合率为９６．３％（２６／２７）；与冠状动脉造影、外科手术后临床及     

Comparison of Tc-99m HMPAO fast SPECT with Tc-99m HMPAO conventional SPECT in patients with acute stroke.

Tc-99m HMPAO SPECT is more likely to detect a stroke in early stages than CT. However, a conventional HMPAO SPECT study takes at least 30 minutes to complete. This paper compares fast Tc-99m HMPAO SPECT scans and conventional Tc-99m HMPAO SPECT scans with respect to spatial resolution and diagnostic efficacy in vitro and in a small series of patients, respectively. The spatial resolution of fast Tc-99m HMPAO SPECT did not match that of images obtained from conventional SPECT, though the difference proved to be of no clinical significance. Since fast SPECT requires only one-fourth to one-fifth the time necessary for conventional SPECT, it may be more suitable for investigating cases of acute stroke in critical clinical situations.     

Prognostic assessment of uncomplicated first myocardial infarction by exercise echocardiography and Tc-99m tetrofosmin gated SPECT

BACKGROUND: We evaluate the prognostic value of stress echo and gated single photon emission computed tomography (SPECT) after a first uncomplicated acute myocardial infarction. METHODS AND RESULTS: We used predischarge maximal subjective exercise echocardiography and gated SPECT with technetium 99m tetrofosmin to prospectively study 103 patients younger than 70 years with a first acute myocardial infarction. During a 12-month follow-up period, 2 patients died, 9 had heart failure, and 29 had ischemic complications (4 reinfarction and 25 angina). Predictive variables for heart failure in multivariate analysis were ejection fraction evaluated by echocardiography (odds ratio [OR] 8.5, P =.016) or by gated SPECT (OR 10.7, P =.009). Predictive variables for ischemic complications in multivariate analysis were less than 5 metabolic equivalents (METS) in exercise test (OR 5.2, P =.007) and greater than 15% ischemic extent in the polar map (OR 3.6, P =.04) of SPECT. CONCLUSIONS: Exercise echocardiography and Tc-99m tetrofosmin gated SPECT were predictive for heart failure, but exercise SPECT was the only test with predictive power for ischemic complications.     

The prognostic value of ECG-gated SPECT imaging in patients undergoing stress Tc-99m sestamibi myocardial perfusion imaging

BACKGROUND: The ability of stress radionuclide myocardial perfusion imaging to predict adverse cardiac events is well accepted. As left ventricular systolic function has also been shown to be an important prognostic indicator, the objective of this study was to determine whether electrocardiography (ECG)-gated single photon emission computed tomography (SPECT) functional data add additional power. METHODS AND RESULTS: In this study 3207 patients who underwent stress myocardial perfusion imaging with ECG gating, without early (相似文献   

Prognostic value of stress Tc-99m tetrofosmin SPECT in patients with previous myocardial infarction: Impact of scintigraphic extent of coronary artery disease

BACKGROUND: Our objective was to assess the prognostic value of the scintigraphic extent of coronary artery disease on stress technetium 99m tetrofosmin single photon emission computed tomography in patients with previous myocardial infarction. METHODS AND RESULTS: We studied 383 patients (280 men and 103 women; mean age, 60 +/- 11 years) more than 3 months after an acute myocardial infarction by exercise bicycle or dobutamine (up to 40 mug . kg -1 . min -1 ) stress Tc-99m tetrofosmin myocardial perfusion tomography. Stress images were acquired 1 hour after stress, and rest images were acquired 24 hours after stress testing. An abnormal study was defined as one demonstrating a reversible or fixed perfusion abnormality. Myocardial segments were assigned to corresponding coronary arteries as follows: the apex, anterior wall, and anterior septum were assigned to the left anterior descending coronary artery; the posterolateral wall was assigned to the left circumflex artery; and the basal posterior septum and inferior wall were assigned to the right coronary artery. During a mean follow-up of 4.3 +/- 2.1 years, 48 cardiac events occurred (36 cardiac deaths and 12 nonfatal myocardial infarctions). Myocardial perfusion was normal in 51 patients, abnormal in a single-vessel distribution in 170 patients, and abnormal in a multivessel distribution in 162 patients. The annual cardiac event rates in these groups were 0.4%, 2.6%, and 4%, respectively. In a multivariate analysis model, independent predictors of cardiac events were diabetes mellitus (odds ratio [OR], 2.3; 95% confidence interval [CI], 1.4-4.5), history of congestive heart failure (OR, 2.7; 95% CI, 1.4-4), age (OR, 1.05; 95% CI, 1.01-1.08), and scintigraphic extent of coronary artery disease (OR, 4.2; 95% CI, 1.8-9.1). CONCLUSION: Stress Tc-99m tetrofosmin myocardial perfusion imaging provides independent prognostic information for the risk stratification of patients with previous myocardial infarction. The event rate is directly related to the scintigraphic extent of coronary artery disease. Patients with normal perfusion have an excellent event-free survival rate.     

Estimation with Tc-99m tetrofosmin SPECT of salvaged myocardial mass after emergent reperfusion therapy in acute myocardial infarction

OBJECTIVES: The purpose of this study was to validate a new quantitative index of salvaged myocardial mass calculated from Tc-99m tetrofosmin SPECT for evaluating the therapeutic effect of emergent reperfusion therapy in acute myocardial infarction (AMI). METHODS: Tc-99m tetrofosmin SPECT was performed before and after emergent percutaneous transluminal coronary angioplasty (PTCA) in eight patients with AMI. In the pre-PTCA study, Tc-99m tetrofosmin was injected before emergent PTCA. Two weeks after the PTCA, post-PTCA study was performed. As a quantitative index of salvaged myocardial mass, salvaged myocardial volume (SMV) was defined as the difference of myocardial functional volume between the SPECT studies before and after the PTCA. To investigate the clinical significance of SMV, SMV was compared with the grade of therapeutic efficacy determined visually from pre- and post-PTCA SPECT images and clinical parameters, namely peak creatine phosphokinase level (pCK) and the time from the onset of the AMI to reperfusion (RPT). RESULTS: SMV showed a significant correlation with the visual grade of therapeutic efficacy (r = 0.737, p < 0.037) and a trend toward significant correlation with pCK (r = -0.622, p < 0.1). SMVs in early- and late-reperfusion groups (RPT < or = 6 hr and RPT > 6 hr) were 30.0 +/- 14.0 and -6.2 +/- 25.5 ml, showing a greater mean SMV value in the early-reperfusion group (p < 0.07). CONCLUSION: SMV could be used as a quantitative index of salvaged myocardial mass for evaluating the therapeutic effect of emergent reperfusion therapy.     

99Tcm-HL91 SPECT探测缺血存活心肌的初步应用研究

目的 研究99Tcm-4,9-二氮-3,3,10,10-四甲基十二烷-2,11-二酮肟(99Tcm-HL91)在缺血心肌中的显像表现,探讨99Tcm-HL91探测缺血但存活心肌的价值.方法 18例已确诊为心肌缺血或心肌梗死的患者均行99Tcm-甲氧基异丁基异腈(99Tcm-MIBI)与99Tcm-HL91心肌灌注显像.在心脏短轴图像上通过感兴趣区技术获取缺血区与正常心肌组织的平均放射性计数,获得99Tcm-MIBI与99Tcm-HL91在局部缺血区与正常心肌组织的放射性比值.结果 10例患者在99Tcm-MIBI显像的放射性稀疏或缺损区而在99Tcm-HL91 SPECT可见到明显的放射性充填;其余8例患者99Tcm-HL91显像心肌摄取不高.结论 99Tcm-HL91可选择性地被存活乏氧心肌摄取,与99Tcm-MIBI SPECT联合应用,可望有效提高检测存活心肌的效能.