Incremental value of left ventricular ejection fraction for detection of multivessel coronary artery disease in exercise (201)Tl gated myocardial perfusion imaging.

Assessment of reversible defects in exercise (201)Tl perfusion SPECT has low sensitivity and high specificity for detection of multivessel coronary artery disease (CAD). The goal of this study was to evaluate whether the left ventricular ejection fraction (LVEF) in exercise (201)Tl gated SPECT had incremental diagnostic value over perfusion data for detection of multivessel CAD. METHODS: One hundred eighty-two patients underwent exercise (201)Tl gated SPECT. Automated LV function analysis software was used for calculation of the postexercise and the rest LVEF. The best threshold between 0- to 1-vessel CAD and 2- to 3-vessel CAD was determined as the cutoff that on receiver-operating-characteristic analysis resulted in the best sensitivity for detection of multivessel CAD with an associated specificity of >90%. RESULTS: Only 18 (26.9%) of 67 patients with multivessel CAD had reversible defects in multiple territories. Sensitivities of the postexercise and the rest LVEF and the worsening of the LVEF by exercise did not differ from those of perfusion data alone. Sensitivities of the combination of perfusion data and the postexercise and rest LVEF did not differ from those of perfusion data alone, whereas the sensitivity of the combination of perfusion data and worsening of the LVEF (i.e., reversible defects in multiple territories or worsening of the LVEF >5.6% [or both]) was significantly greater than that of perfusion data alone (43.3% vs. 26.9%; P < 0.05), with an acceptable level of specificity (90.4%). CONCLUSION: The worsening of the LVEF by exercise has the potential to detect patients with multivessel CAD among those without multivessel patterns of reversible defects.     

A comparison of Tl-201 stress-reinjection-prone SPECT and Tc-99m-sestamibi gated SPECT in the differentiation of inferior wall defects from artifacts

The frequency of false positive results obtained from the inferior myocardial region using single photon emission computed tomography (SPECT) myocardial perfusion scintigraphy is significantly higher than that obtained from other regions. Several methods, such as prone-position imaging, have been proposed to overcome this diagnostic problem. The aim of the present study was to compare the results of Tc-99m-sestamibi gated SPECT and Tl-201 prone SPECT in the differentiation of inferior wall artifacts from true defects. For this purpose, 38 subjects, whose coronary anatomies were documented on angiography, underwent same-day stress-rest Tc-99m-sestamibi gated SPECT and Tl-201 stress-reinjection-prone (whose standard supine images demonstrated fixed defects on the inferior wall) SPECT. Gated SPECT was performed by 8 frames per cycle acquisition over a 180 degree rotation on 30 projections. Four gated SPECT slices were obtained on mid-ventricular vertical long axis, horizontal long axis and apical and basal short axis planes, and displayed in cine-format. Both Tl-201 prone imaging and Tc-99m-sestamibi gated analysis increased the specificity of inferior wall disease detection remarkably from 54% to 85% and 46% to 82%, respectively (P<0.05). The difference between diagnostic accuracies was not significant (80% and 82%, respectively) (P > 0.05). The positive predictive values for true defects were 96% for Tl-201 prone imaging and 94% for Tc-99m-sestamibi gated imaging. Based on segmental analysis, the two modalities showed fair agreement (kappa = 0.44 for standard supine protocols, kappa = 0.46 for Tl-201 prone and Tc-99m-sestamibi gated SPECT). It can be concluded that Tc-99m-sestamibi gated SPECT, requiring only two-step acquisition, may potentially increase the test specificity for coronary artery disease (CAD) of the inferior wall as well as does Tl-201 stress-reinjection-prone SPECT. By giving functional information, it seems the most practical method in daily use for supplying the most extensive information about patients with suspected or known CAD.     

Incremental value of assessment of regional wall motion for detection of multivessel coronary artery disease in exercise (201)Tl gated myocardial perfusion imaging.

Assessment of reversible perfusion defects in exercise (201)Tl perfusion SPECT has low sensitivity and high specificity for detection of multivessel coronary artery disease (CAD). The goal of this study was to evaluate whether worsening of left ventricular regional wall motion assessed by an automated algorithm in exercise (201)Tl electrocardiography-gated SPECT had incremental diagnostic value over perfusion data for detection of multivessel CAD. METHODS: Two hundred one patients underwent exercise (201)Tl gated SPECT. Software that automatically analyzes left ventricular function was used to assess exercise and rest regional wall motion. Regional wall motion on initial images was compared with that on rest images, that is, delayed images for patients without reinjection images and reinjection images for patients with reinjection images. The left ventricle was divided into 9 segments, with individual segments assigned to 3 coronary territories. Worsening of wall motion was defined as worsening in any segment on initial images compared with rest images. RESULTS: Of 73 patients with multivessel CAD, 20 (27.4%) had reversible perfusion defects in multiple coronary territories, 26 (35.6%) exhibited worsening of regional wall motion in multiple territories, and 37 (50.7%) had reversible perfusion defects or worsening of regional wall motion in multiple territories. The sensitivity of the combination of reversible perfusion defect and worsening of regional wall motion was significantly higher than that of reversible perfusion defect alone for detection of multivessel CAD (50.7% vs. 27.4%, P < 0.05). The specificity of the combination of reversible perfusion defect and worsening of regional wall motion for detecting multivessel CAD did not differ from that of reversible perfusion defect alone and that of worsening of regional wall motion alone (94.5% vs. 99.2% and 97.7%, respectively, P = not statistically significant). CONCLUSION: Combined assessment of worsening of left ventricular regional wall motion by exercise and perfusion data in exercise (201)Tl gated myocardial SPECT was more sensitive, with acceptable specificity, than was assessment with perfusion data alone for detection of multivessel CAD.     

Accuracy of left ventricular ejection fraction determined by gated myocardial perfusion SPECT with Tl-201 and Tc-99m sestamibi: Comparison with first-pass radionuclide angiography

BACKGROUND: We compared estimates of left ventricular ejection fraction (LVEF) assessed by gated single photon emission computed tomography (SPECT), using both technetium-99m sestamibi and thallium-201, with those obtained by first-pass radionuclide angiography (FPRNA) in patients with a broad spectrum of LVEF and perfusion abnormalities. METHODS: Sixty-three patients were randomly selected to undergo a dual isotope gated SPECT study (rest Tl-201 followed by adenosine Tc-99m sestamibi scintigraphy). Studies were processed by use of the Cedars quantitative gated SPECT software. FPRNA was acquired during an intravenous bolus injection of Tc-99m sestamibi and processed with a commercially available software. RESULTS: The estimates of LVEF were similar (P = NS) with Tl-201 gated SPECT (54% +/- 15%), Tc-99m gated SPECT (54% +/- 16%), and FPRNA (54% +/- 12%). There was an excellent correlation between Tc-99m and Tl-201 gated SPECT (Pearson's r = 0.92, P < .0001). There were also good linear correlations between Tc-99m sestamibi gated SPECT and FPRNA (Pearson's r = 0.85, P < .0001), as well as between Tl-201 gated SPECT and FPRNA (Pearson's r = 0.84, P < .0001). In the 16 patients with LVEF < 50%, Tc-99m sestamibi gated SPECT and FPRNA (Pearson's r = 0.84, P < .0001) and Tl-201 gated SPECT and FPRNA (Pearson's r = 0.92, P < .0001) correlated well. CONCLUSION: LVEF can be accurately assessed by gated SPECT with either Tc-99m sestamibi or Tl-201 in properly selected patients with normal or depressed left ventricular function.     

Prediction of left ventricular wall motion recovery after acute myocardial infarction by T1-201 gated SPECT: Incremental value of integrated contractile reserve assessment

BACKGROUND: This investigation tested the application of low-dose dobutamine (LDD) gated single photon emission computed tomography (SPECT) with thallium 201 for myocardial viability detection early after acute myocardial infarction (AMI). METHODS AND RESULTS: Thirty-two hemodynamically stable post-AMI patients (aged 55 +/- 5 years [mean +/- SEM]; 20 men) who were exhibiting regional left ventricular dysfunction underwent stress-redistribution Tl-201 scanning within 4 to 8 days, followed by 2 additional gated SPECT acquisitions after Tl-201 reinjection, at rest and during LDD. A visual 5-point score was computed for segmental radiotracer uptake (0, normal; 4, absent) and a 4-point score for left ventricular wall motion (1, normal; 4, dyskinesis). Predominant viable myocardium in dyssynergic regions was predicted by a mean Tl-201 uptake score of 2 or less or ischemic area of 30% or greater. These indices showed a significant association with wall motion improvement in follow-up echocardiographic studies (overall accuracy = 0.69, sensitivity = 0.93, and specificity = 0.50). Regarding the response to LDD stimulus, an increase in mean wall motion score of 30% or greater was predictive of predominant viable myocardium. Contractile reserve assessment yielded a significant increment in the predictive accuracy for function recovery (overall accuracy = 0.84, sensitivity = 0.71, and specificity = 0.94). CONCLUSIONS: Evaluation of contractile reserve by means of LDD gated SPECT with Tl-201 is safely feasible early after AMI, with incremental value over perfusion assessment alone for myocardial viability detection.     

Intravenous dipyridamole thallium-201 SPECT imaging in patients with left bundle branch block

Tl-201 exercise imaging in patients with left bundle branch block (LBBB) has proven to be indeterminate for significant left anterior descending (LAD) coronary artery stenosis because of the presence of immediate septal perfusion defects with redistribution on delayed images in almost all cases. Tl-201 redistribution occurs regardless of the presence or absence of LAD stenosis. Nineteen patients having LBBB were evaluated with dipyridamole Tl-201 SPECT. Fourteen of these subjects had normal dipyridamole Tl-201 SPECT imaging. Three patients had normal coronary angiograms. None of the remaining 11 patients with normal dipyridamole Tl-201 SPECT images was found to have clinical coronary artery disease in a 5-11 month follow-up period. Five patients had abnormal septal perfusion. Four underwent coronary angiography. One had a significant LAD stenosis. The single patient with septal redistribution who refused to undergo coronary angiography died shortly thereafter of clinical coronary artery disease. This preliminary work suggests that dipyridamole Tl-201 SPECT may be more useful for excluding LAD stenosis in patients with LBBB than Tl-201 exercise imaging.     

Serial assessment of left ventricular function in various patient groups with Tl-201 gated myocardial perfusion SPECT

Purpose The present study was performed to assess stress-related left ventricular (LV) function variations in various patient groups and to determine if they were affected by sex or the type of stress experienced. We used thallium (Tl)-201 gated myocardial perfusion single-photon emission computed tomography (SPECT) for the analysis. Materials and methods A total of 270 patients were examined by electrocardiography-gated myocardial perfusion SPECT imaging to assess LV function. After injection of Tl-201 at a dose of 111 MBq at peak stress, SPECT scans were acquired at 10 min (after stress) and 3 h (rest) after injection on a three-headed camera. Results In the normal perfusion group, the mean LV ejection fraction (LVEF) was significantly higher, and both the end-diastolic volume index (EDVI) and end-systolic volume index (ESVI) were significantly lower in women than in men (P < 0.05). Poststress stunning occurred in 29 of 98 patients (30.0%) in the ischemia group and in 42 of 90 patients (46.7%) in the fixed group. There was a significant difference in poststress stunning between bicycle ergometer stress and dipyridamole stress (P < 0.05). Conclusion In patients with normal perfusion, LVEF, EDVI, and ESVI determined by gated Tl-201 SPECT should be corrected for sex. In addition, the influence of the type of stress should be considered when assessing stress-related LV function variations.     

Relationship between contractile reserve,Tl-201 uptake,and collateral angiographic circulation in collateral-dependent myocardium: Implications regarding the evaluation of myocardial viability

BACKGROUND: The aim of this study was to compare collateral angiographic circulation (CC), thallium 201 single photon emission computed tomography (SPECT), low-dose dobutamine echocardiography (LDDE), and their combination in identifying viable myocardium beyond a chronic occlusion. METHODS AND RESULTS: We studied 33 consecutive patients with a chronic occluded coronary artery and regional ventricular dysfunction who underwent dobutamine infusion (5-10 microg x kg(-1) x min(-1)), Tl-201 SPECT, and coronary revascularization (15 patients underwent coronary artery bypass grafting and 18 patients percutaneous transluminal coronary angioplasty). Echocardiography and Tl-201 SPECT at rest were repeated 90 +/- 48 days after revascularization. For viability assessment, Tl-201 SPECT showed the best sensitivity and accuracy (77% and 72%, respectively) compared with LDDE (64% and 63%, respectively) and CC (74% and 55%, P < .05 vs Tl-201 SPECT). Specificity was significantly better for both Tl-201 SPECT (65%) and LDDE (62%) compared with collateral circulation (27%, P < .001 vs Tl-201 SPECT and LDDE). Furthermore, combined Tl-201 SPECT and LDDE data improved specificity (from 88% to 92%) and positive predictive power (from 75% to 78%) but not global accuracy. A direct relationship between the number of viable segments and global functional recovery after revascularization was found only in the case of Tl-201 SPECT (r = 0.48, P = .04). CONCLUSIONS: This study demonstrates that CC has a very low specificity in the evaluation of viability in collateral-dependent myocardium and that LDDE has a very low sensitivity, whereas Tl-201 SPECT is the most reliable method, particularly in akinetic segments, and optimally identifies patients who will mostly benefit from revascularization in terms of ventricular functional improvement. No additional advantages in terms of accuracy were found when Tl-201 SPECT and LDDE data were combined.     

Left ventricular ejection fraction and volumes on rest gated 201Tl perfusion SPECT: comparison with two-dimensional echocardiography

BACKGROUND: Rest gated 201Tl images are considered to be of poor count statistics due to lower energy and low photon flux of 201Tl in addition to increased attenuation and low dose that can be administered. We compared the left ventricular ejection fraction (LVEF), end diastolic (EDV) and end systolic volume (ESV) obtained on 4 h gated rest 201Tl myocardial perfusion single photon emission computed tomography (SPECT) with those obtained by two-dimensional echocardiography (2-D ECHO) in patients with known or suspected coronary artery disease (CAD). METHODS: Eighty-two consecutive patients who underwent gated 201Tl stress-rest myocardial perfusion SPECT and 2-D ECHO were studied. The gated thallium images were processed with Siemens e-soft autocardiac processor and LVEF, EDV and ESV were evaluated using Emory Cardiac Toolbox. The same parameters were also assessed on the 2-D ECHO using the modified Simpson method for comparison. RESULTS: Out of 82 rest gated images, one study was excluded because of poor count statistics. In 81 (99%) patients there was good linear correlation with 2-D ECHO values and rest gated 201Tl SPECT images for EDV, ESV and LVEF. Pearson's correlation co-efficient (r value) for EDV, ESV and LVEF between the two methods was 0.78, 0.79 and 0.88, respectively. A Bland-Altman plot showed close agreement with LVEF but not for EDV and ESV. CONCLUSION: These results suggest that the 4 h rest gated 201Tl study gives a reliable value for the LVEF compared to 2-D ECHO and can be used in routine clinical practice.     

Assessment of ejection fraction with Tl-201 gated SPECT in myocardial infarction: Precision in a rest-redistribution study and accuracy versus planar angiography

BACKGROUND. Viability and left ventricular ejection fraction (LVEF) are essential measures for the assessment of myocardial infarction (MI). These 2 variables may be evaluated simultaneously by means of thallium-201 gated single photon emission computed tomography (SPECT); however, the precision and accuracy of LVEF measurements with this isotope remain controversial, particularly in cases of extended perfusion defects and poor count densities. METHODS AND RESULTS. Fifty patients with a history of MI underwent a 20-minute rest and a 4-hour redistribution Tl-201 gated SPECT viability protocol, immediately followed by a technetium-99m planar equilibrium radionuclide angiography (ERNA). On gated SPECT images, various count statistics were calculated, and perfusion was automatically quantified by means of CardioMatch, which provided both the size and severity of MI defects. Rest and redistribution LVEFs were determined from gated SPECT with Germano's algorithm, whereas LVEFs were calculated from ERNA using the manufacturer's software. Mean LVEF values calculated with rest gated SPECT, redistribution gated SPECT, and planar ERNA were 30% +/- 13%, 30% +/- 13% and 33% +/- 13%, respectively. Significant differences between repeated gated SPECT LVEFs were not shown by means of the paired t test. Correlation coefficients were high between 20-minute and 4-hour scans (r = 0.89) and between gated SPECT and ERNA (r = 0.88 and r = 0.92 at 20 minutes and 4 hours, respectively). Additionally, close agreement between gated SPECT and ERNA was shown by means of the Bland-Altman plot, despite an underestimation of 3 units. Finally, neither the technical conditions (count density, heart rate, lung uptake, etc) nor the perfusion alteration (size, severity, redistribution) appeared to interfere with the precision and accuracy of gated SPECT LVEF measurement. CONCLUSION. Tl-201 gated SPECT is a precise method for assessing LVEF within the same patient at 4-hour intervals, even with a substantial count decay, and it gives accurate results compared with planar ERNA, even in the case of large perfusion defects.     

Comparative performance of gated perfusion SPECT wall thickening, delayed thallium uptake, and F-18 fluorodeoxyglucose SPECT in detecting myocardial viability

To evaluate the comparative abilities of gated single photon emission computed tomography (SPECT) wall thickening, delayed thallium-201 (Tl-201) SPECT, and F-18 fluorodeoxyglucose (FDG) SPECT in detecting myocardial viability, 23 patients with previous myocardial infarction and clinically suspected viability were studied. Each patient had at least 1 extensive fixed perfusion defect on rest/stress technetium-99m sestamibi SPECT. A total of 41 major vascular territories had fixed defects. The mean (+/- 1 SD) left ventricular ejection fraction determined from gated perfusion SPECT was 26% +/- 11%. Wall thickening was assessed in a semiquantitative fashion by the regional increase in myocardial intensity during systole and was considered normal when a > or = 20% increase was observed. Tl-201 SPECT was acquired 4 hours after resting tracer injection was administered. Viability was considered present when regional defect Tl-201 count density, determined by quantitative analysis, was > 20% greater than that on the resting sestamibi scan. FDG SPECT was performed independently with a 10 mCi F-18 FDG dose after oral glucose loading was performed. A camera equipped with ultrahigh energy collimation was used. Quantitative criteria for viability were the same as for Tl-201. In the 23 patients viability within the fixed sestamibi defects was manifest by preserved wall thickening in 8 patients, delayed Tl-201 uptake in 10 patients, and FDG uptake in 18 patients. Nine major vascular territories with fixed defects were judged viable by wall thickening, 11 by Tl-201 SPECT, and 24 by FDG SPECT (P = .0009). We conclude that FDG SPECT demonstrates more evidence of myocardial viability than either gated sestamibi wall thickening or delayed Tl-201 SPECT.     

Relationship of transient ischemic dilation in dipyridamole myocardial perfusion imaging and stress-induced changes of functional parameters evaluated by Tl-201 gated SPECT

BACKGROUND: This study assessed whether transient ischemic dilation (TID) of the left ventricle is related to ischemic stunning, manifested by stress-induced decrease of left ventricular ejection fraction (LVEF) and worsening of wall motion, by use of dipyridamole-stress and redistribution thallium 201 gated single photon emission computed tomography (SPECT). METHODS AND RESULTS: Ninety-two consecutive patients undergoing dipyridamole Tl-201 gated SPECT were included. Patients with a TID ratio in the highest quartile were defined as having TID. In patients with TID, end-diastolic volume (EDV) and end-systolic volume (ESV) were both significantly greater on dipyridamole-stress images than on redistribution images (P < .001). The degree of enlargement was much greater for ESV than EDV. In patients without TID, EDV and ESV were both decreased after stress (P < .001). Patients with TID had a lower mean LVEF on dipyridamole-stress images than on redistribution images (P < .001). Patients without TID had a higher mean LVEF on dipyridamole-stress images than on redistribution images (P < .001). Patients with TID had a significant worsening of global wall motion on dipyridamole-stress images than on redistribution images (P < .001), but patients without TID did not. CONCLUSION: TID was significantly correlated with ischemic stunning, and the enlargement of ESV was an important factor resulting in TID.     

Consideration of perfusion reserve in viability assessment by myocardial Tl-201 rest-redistribution SPECT: A quantitative study with dual-isotope SPECT

BACKGROUND: To optimize the use of thallium 201 rest-redistribution study in Tl-201/technetium 99m sestamibi dual-isotope single photon emission computed tomography (SPECT), the predictability of Tl-201 rest-redistribution for viable myocardium was examined according to the degree of perfusion reserve. METHODS AND RESULTS: Twenty patients with both unstable angina and left ventricular dysfunction were enrolled. Tl-201 rest-dipyridamole stress Tc-99m sestamibi gated SPECT/Tl-201 24-hour redistribution SPECT was performed before and 3 months after coronary artery bypass grafting. Through use of a 20-segment model, segmental stress perfusion, rest perfusion, and systolic thickening were quantified on gated SPECT by means of automatic quantitation software. Perfusion was expressed as the average percentage of maximal radioactivity uptake. To represent perfusion reserve, the perfusion difference score (PDS) was defined as rest perfusion minus stress perfusion. A low PDS indicated little or no inducible ischemia, and a high PDS indicated inducible ischemia. In dysfunctional myocardium, viability was defined by the improvement of thickening after coronary artery bypass grafting. The overall predictability of Tl-201 redistribution for viability was 0.709 of the area under the curve (AUC) in receiver operating characteristic analysis. With a cutoff of 7, predictability was significantly better in the low PDS group (AUC = 0.785) than in the high PDS group (AUC = 0.582). CONCLUSIONS: The predictability of Tl-201 rest-redistribution for viability differs according to perfusion reserve. It was more reliable for dysfunctional myocardium with persistent perfusion decrease. On the basis of the continuum hypothesis of chronic stunning and hibernation, we suggest that dysfunctional myocardium with persistent perfusion decrease should be assessed by Tl-201 redistribution SPECT.     

Unilateral left pulmonary T1-201 uptake on raw data images of dual-isotope gated SPECT due to pulmonary infiltrates and atelectasis

Diffuse pulmonary thallium 201 uptake on dual-isotope gated single photon emission computed tomography (SPECT) at rest is usually bilateral and related to coronary artery disease (CAD). We present a patient who had unilateral left pulmonary T1-201 uptake and normal left ventricular (LV) perfusion and function. The abnormal diffuse pulmonary Tl-201 uptake in the left lung corresponded to infiltrates and atelectasis on the concurrent radiograph and computed tomogram of the chest.     

Dipyridamole technetium-99m-2-methoxy isobutyl isonitrile tomoscintigraphic imaging for identifying diseased coronary vessels: comparison with thallium-201 stress-rest study

A same-day double injection protocol employing 99mTc-methoxyisobutyl isonitrile (MIBI) and myocardial single-photon emission computed tomography (SPECT) for detecting coronary artery disease (CAD) was assessed in 30 patients. SPECT was performed 1 hr after a first injection (250 MBq) of 99mTc-MIBI, given after 0.56 mg/kg dipyridamole (DPD) infusion. Patients were then reinjected at rest (750 MBq) and were reimaged 1 hr later. Within 1 wk, all patients underwent a complete stress-rest SPECT thallium study. Of the 330 myocardial segments evaluated, 25 were judged ischemic by both techniques, while persistent defects were demonstrated in 50 and in 47 with 99mTc-MIBI and 201TI, respectively. Six regions were considered for diseased vessels identification. Sensitivity and specificity for CAD were 100% and 75%, respectively, for both 201TI and 99mTc-MIBI. Sensitivity for identification of diseased vessels by 201TI was 68% for LAD, 89% for RCA, and 80% for LCX as opposed to 75%, 89% and 80%, respectively, by 99mTc-MIBI. Specificity was 93% in both cases for LAD, 73% and 63% for RCA, and 53% and 46% for LCX.     

99Tcm-NOET门控心肌灌注SPECT评价冠心病的价值

目的评价99Tcm--双（N-乙氧基,N-乙基-二硫代氨基甲酸酯）氮化锝（99Tcm-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925MBq 99Tcm-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99Tcm-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=42．60：4,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）％1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99Tcm-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?     

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.     

Effects of dipyridamole on left ventricular function

BACKGROUND: Changes induced by dipyridamole infusion on left ventricular function in healthy individuals have not been investigated by gated myocardial perfusion single photon emission computed tomographic (SPECT) imaging. METHODS AND RESULTS: This study examined the amplitude and duration of changes induced by dipyridamole infusion on left ventricular function as assessed by technetium 99m sestamibi gated SPECT in 18 subjects with a low likelihood of coronary artery disease. Twenty mCi (740 MBq) of Tc-99m sestamibi were injected at rest. Three different consecutive gated SPECT images were performed 60 minutes later: baseline at rest, during the infusion of 0.76 mg/kg of dipyridamole, and 1 hour later. No patient received aminophylline. Left ventricular ejection fraction (LVEF), end-diastolic volume, and end-systolic volume were automically computed. Heart rate (HR) and blood pressure were regularly monitored. Mean LVEF was 63.2% +/- 8.0% baseline at rest, increased to 73.8% +/- 8.2% (P = .0001) during dipyridamole infusion, and returned to baseline values (63.0% +/- 7.5%) 1 hour later. End-diastolic volume did not vary significantly, and end-systolic volume decreased (from 32.2 +/- 19.5 to 26.6 +/- 17.9 u, P = .002) and returned to baseline values (32.7 +/- 15.6 u) 1 hour later. Dipyridamole induced moderate HR acceleration (from 80.2 +/- 15.0 to 96.5 +/- 9.6 beats/min, P < .001) and a slight decrease in diastolic blood pressure (from 80.6 +/- 8.1 to 70.1 +/- 9.0 mm Hg, P < .001). However, 1 hour later, HR and blood pressure had returned to baseline values. CONCLUSIONS: Dipyridamole increases LVEF and HR and decreases diastolic blood pressure slightly in healthy individuals. Because dipyridamole gated SPECT imaging acquisition is usually started 60 minutes after dipyridamole infusion, LVEF is in fact estimated at rest.     

Comparative evaluation of Tc-99m MIBI and Tl-201 chloride SPECT in non-small-cell lung cancer mediastinal lymph node metastases

PURPOSE: To compare the utility of Tc-99m MIBI SPECT and Tl-201 chloride SPECT for presurgical assessment of lung cancer mediastinal lymph node metastases. METHODS: Forty-one patients with non-small-cell lung cancer underwent dual-isotope imaging with Tl-201 chloride and Tc-99m MIBI and were evaluated for mediastinal lymph node involvement. RESULTS: The sensitivity rates of early and delayed Tc-99m MIBI SPECT and of early and delayed Tl-201 chloride SPECT for detecting mediastinal nodal metastases were 69%, 69%, 92%, and 92%, respectively. The corresponding specificity rates were 96%, 96%, 93%, and 96%. CONCLUSION: Tl-201 chloride SPECT is superior to Tc-99m MIBI SPECT when used to detect mediastinal lymph node metastases in patients with non-small-cell lung cancer.     

~(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.