Tc-99m Sestamibi SPECT Research Articles

Effect of left ventricular function on diagnostic accuracy of FDG SPECT

Fluorine-18 fluorodeoxyglucose (FDG) SPECT has emerged as an alternative to dedicated PET imaging. However, it remains uncertain whether FDG SPECT is an as accurate for viability assessment as FDG PET in patients with severely reduced left ventricular function. The aim of the study was to assess the diagnostic accuracy of FDG SPECT in a head-to-head comparison with FDG PET, and divide the patients according to the severity of left ventricular dysfunction. A total of 47 patients, with a history of myocardial infarction underwent FDG/perfusion (99mTc-sestamibi or 201Tl) SPECT as well as FDG/13N-ammonia PET. The patients were divided into 2 subgroups based on the left ventricular ejection fraction (LVEF) (35% cutoff). The left ventricular myocardium was divided into 13 segments, and each segment was classified as viable or scar using a semi-quantitative scoring system based on defect severity and the presence or absence of perfusion-FDG mismatch. Of the 47 patients studied, 23 had LVEF < 35% (low LVEF group; mean 25 +/- 7%), whereas the remaining 24 had LVEF > or = 35% (high LVEF group; mean 47 +/- 6%). In the low LVEF group, 213 segments (71%) were dysfunctional, as compared to 102 (33%) in the high LVEF group. The agreement for detection of viability between PET and SPECT in the low LVEF group was 82% (kappa 0.63), which was not different from the agreement in the high LVEF group (85%, kappa 0.66, p = 0.42 versus low LVEF group). The results indicate that FDG SPECT can be used for tissue viability assessment regardless of the severity of left ventricular dysfunction.

748 Quantitative assessment of perfusion of healthy and LAD-occluded rats with myocardial contrast echocardiography and 99mTc-sestamibi SPECT

748 Quantitative assessment of perfusion of healthy and LAD-occluded rats with myocardial contrast echocardiography and 99mTc-sestamibi SPECT

Erroneous Left Ventricular Cavity Size Measurements on Myocardial Perfusion SPECT Resulting From Transient Arrhythmias

Transient ischemic dilatation (TID) of the left ventricle during stress on myocardial perfusion imaging is a sign of severe coronary artery disease. Factors other than ischemia can transiently influence left ventricular size, however, and TID ratios can be misleading if these factors are not properly identified. We describe 4 cases of stress-rest Tc-99m sestamibi SPECT myocardial perfusion imaging in which both abnormally high and low TID ratios were seen as a result of the presence of transient supraventricular tachyarrhythmias that reduced cardiac filling time and corresponding left ventricular volumes.

Assessment of Right and Left Ventricular Perfusion in Patients with Right Bundle Branch Block

Patients with conduction abnormalities may have abnormal images on perfusion scintigraphy without evidence of coronary artery disease (CAD). Based on the presence of left ventricular perfusion abnormalities in left bundle branch block and taking advantage of the Tc-99m sestamibi for the assessment of myocardial perfusion of both ventricles, we aimed to evaluate right (RV) and left (LV) myocardial perfusion in patients with right bundle branch block (RBBB). This study included 21 patients with RBBB and 21 control subjects without conduction abnormality. None had previous myocardial infarction, known CAD, left ventricular hypertrophy, LVEF <55%, congenital, pulmonary or valvular heart disease. Rest and stress SPECT images were obtained using 1-d Tc-99m sestamibi SPECT protocol. Regional perfusion of LV and RV myocardium was semiquantitatively evaluated. Also, RV/LV uptake ratio was calculated in two different ways. In patients with RBBB, the normality ratios of RV and LV myocardial perfusion were very high (both 90.5%) and not different from those of patients with normal intraventricular conduction. In the comparison of RV/LV uptake ratios, no significant difference was found between the RBBB and control groups. LV perfusion, RV perfusion or R-to-L perfusion ratio were not significantly influenced by the conduction abnormality in this selected patient population with RBBB. Tc-99m sestamibi myocardial scintigraphy could help in the exclusion of myocardial ischemia in patients with RBBB.

37.02 Improved early post-stress TC99m-sestamibi myocardial perfusion SPECT using an energy-based scatter correction method

37.02 Improved early post-stress TC99m-sestamibi myocardial perfusion SPECT using an energy-based scatter correction method

34.22 Attenuation-corrected TC-99m sestamibi SPECT compared with RB-82 myocardial perfusion PET

34.22 Attenuation-corrected TC-99m sestamibi SPECT compared with RB-82 myocardial perfusion PET

Myocardial perfusion images (SPECT Tc99m SESTAMIBI) in heart failure patients and their association with ventricular arrhythmias profile

Myocardial perfusion images (SPECT Tc99m SESTAMIBI) in heart failure patients and their association with ventricular arrhythmias profile

Predictors of differences in left ventricular ejection fraction and volumes determined by quantitative gated rest and post-stress Tc-99m sestamibi SPECT

Predictors of differences in left ventricular ejection fraction and volumes determined by quantitative gated rest and post-stress Tc-99m sestamibi SPECT

Prognostic value of heart rate response in patients with atrial fibrillation undergoing gated SPECT Tc-99m sestamibi exercise stress testing

Prognostic value of heart rate response in patients with atrial fibrillation undergoing gated SPECT Tc-99m sestamibi exercise stress testing

Real time assessment of myocardial perfusion with intravenous contrast during adenosine stress echocardiography after percutaneous revascularization.Comparison with 99mTc-sestamibi spect imaging

Real time assessment of myocardial perfusion with intravenous contrast during adenosine stress echocardiography after percutaneous revascularization.Comparison with 99mTc-sestamibi spect imaging

Gender differences in patients who develop st segment elevation during stress myocardial perfusion imaging (MPI)

Background: There is evidence that patients with ST elevation on stress EKG coupled with reversible perfusion defects on MPI are likely to benefit from cardiac intervention. Since there is limited data regarding the frequency and significance of these findings in male and female patients we analyzed the occurrence of ST elevation according to gender in a large group of patients undergoing stress MPI. Methods: We examined stress MPI tests done on 9,273 consecutive patients undergoing MPI for routine clinical indications. Stress tests were done utilizing the Bruce protocol or pharmacologically with adenosine, dipyridamole or dobutamine infusion. MPI was performed with Tl-201 and/or Tc99m sestamibi or tetrafosmin SPECT. ST segment elevation was determined to be present if there was1mm ST segment elevation from baseline present in two contiguous leads. Myocardial perfusion defects at rest and stress were determined to be present according to standard ASNC criteria. Results: Of 9,273 total patients there were 4,357 females and 4,916 males. 74 out of 4,357(1.7%) females and 150 out of 4,916(3.1%) males developed ST segment elevation on stress EKG. MPI demonstrated that 16 out of these 74 women (22%) had reversible perfusion defects compared to 61 out of 150 men (41%) with reversible perfusion defects. 11/16 (69%) female patients underwent left heart catheterization and all 11 (100%) had critical flow limiting lesions amenable to intervention or surgery. 32/61 (52%) male patients underwent left heart catheterization and 24 (75%) had critical flow limiting lesions amenable to intervention or surgery. Of 16 women with reversible perfusion defects, 4 underwent dobutamine, 4 adenosine/dipyradimole and 8 exercise stress. Of 61 men with reversible perfusion defects, 21 underwent dobutamine, 13 dipyradimole/adenosine and 27 exercise stress. Conclusions: ST elevation on stress EKG is less common in females (1.7%) than in males (3.1%) and is likely to be associated with a reversible perfusion defect although less so than in males (22% versus 41%). These females are as likely as males to undergo left heart catheterization and have flow limiting coronary lesions.

Assessment of myocardial perfusion by novice and experienced observers: Does color scale make a difference?

Background: Myocardial perfusion images are traditionally reviewed in gray (GR) scale but various color scales are available, and popular with cardiology trainees. We examined differences in test sensitivity, specificity, and accuracy for a nuclear cardiology trainee, and an experienced observer who used different color scales for myocardial perfusion image (MPI) interpretation. Methods: 30 patients (68±12 yrs; 19 male) who underwent clinically indicated rest TL-201/stress Tc-99m sestamibi SPECT and had coronary angiography within 30 days of MPI were studied. Post-stress images were scored based on a 5-point/17-segment model in GR and Cequal (CE) in random sequence by a nuclear cardiology trainee (1), and an experienced observer (2) independently. Both observers were blinded to the angiographic data. Interobserver and intraobserver agreement were compared by kappa statistic, and McNemar's test for statistical significance (p<0.05) was used for tests' results. Results: (See table). Intraobserver kappa for GR vs. CE was 0.7 for (1), and 0.5 for (2). Interobserver kappa was 0.3 for GR, and 0.6 for CE. Conclusion: Both intraobserver and interobserver agreement was fair. There was a trend for increased sensitivity and accuracy for CE vs. GR for both observers. There was also a trend to increased specificity for an experienced observer with GR. The differences were greater for an experienced observer, resulting in higher accuracy. Sensitivity (1) Specificity (1) Accuracy (1) Sensitivity (2) Specificity (2) Accuracy (2) GR 85% 40% 70% 65% 80% 70% CE 95% 40% 76% 95% 60% 83%

Predictors of differences in left ventricular ejection fraction and volumes determined by quantitative gated rest and post-stress Tc-99m sestamibi SPECT

Background: Quantitative gated SPECT (QGS) is useful in evaluating left ventricular ejection fraction (LVEF), end systolic volume (ESV), and end diastolic volume (EDV). Less is known regarding factors potentially associated with differences in LVEF and volumes obtained from QGS at rest and post-stress. Methods: Using a 2-day protocol, SPECT data was obtained at rest and post-stress with high dose (25 mCi) Tc-99m sestamibi bolus. LVEF, ESV, and EDV were derived from automated Cedars-Sinai QGS software. Of 100 patients prospectively studied, 92 studies were technically adequate. Delta LVEF was defined as QGS rest EF minus QGS post-stress LVEF. Delta ESV and EDV were similarly defined. Results: (See table). LVEF, ESV, and EDV rest and post-stress were highly correlated. LVEF and EDV were higher at rest than post-stress. Summed difference score (SDS) >0 was significantly associated with increased delta LVEF (p=0.02). Mean LVEF post-stress in ischemic patients was 55.0% vs 61.1% in nonischemic patients (p=0.01). SDS=0 was associated with increased delta EDV (p<0.001). Mean post-stress EDV in ischemic patients was 94.4 cc vs 80.1 cc in nonischemic patients (p<0.01). SDS=0 was associated with increased delta ESV (p=0.002). Mean post-stress ESV in ischemic patients was 43.4 cc vs 32.1 cc in nonischemic patients (p<0.01). Conclusion: QGS post-stress is highly correlated with QGS rest for LVEF, EDV, and ESV. The mean QGS rest LVEF and rest EDV are significantly higher than post-stress LVEF and stress EDV. Ischemia is associated with lower QGS post-stress LVEF which may represent post-stress ischemic LV dilatation with increased post-stress ESV and EDV. Rest Post-Stress r p Mean delta p LVEF (%) 61.1 59.2 0.89 <0.001 1.9 <0.001 EDV (cc) 88.1 84.8 0.88 <0.001 3.3 <0.01 ESV (cc) 35.4 35.8 0.93 <0.001 −0.4 NS

Adenosine sestamibi SPECT post-infarction evaluation (INSPIRE) trial: A randomized, prospective multicenter trial evaluating the role of adenosine Tc-99m sestamibi SPECT for assessing risk and therapeutic outcomes in survivors of acute myocardial infarction

Background Preliminary studies indicate that adenosine myocardial perfusion single photon tomography (SPECT) can safely and accurately stratify patients into low and high risk groups early after acute myocardial infarction (AMI). Methods and results INSPIRE is a prospective, randomized multicenter trial which enrolled 728 clinically stable survivors of AMI. Following baseline adenosine sestamibi gated SPECT, patients were classified as low, intermediate or high risk based on the quantified total and ischemic left ventricular (LV) perfusion defect size (PDS). A subset of high risk patients with a LV ejection fraction ≥35% were randomized to a strategy of either intensive medical therapy or coronary revascularization. Adenosine SPECT was repeated at 6-8 weeks to determine the relative effects of anti-ischemic therapies on total and ischemic PDS (primary endpoint). All patients were followed for one year. The baseline demographic, clinical and scintigraphic characteristics of the study population are presented. Adenosine SPECT was performed within 1 day of admission in 12% of patients and in 64% by Day 4. Conclusion The unique study design features of INSPIRE will further clarify the role of adenosine sestamibi SPECT in defining initial patient risk after AMI and in monitoring the benefits of intensive anti-ischemic therapies.

Prognostic significance of normal myocardial perfusion imaging among blacks and hispanics in an inner-city population

Background: Previous studies have shown that the risk of death/MI at 1 year is less than 1% in patients with normal stress myocardial perfusion imaging. However, the racial distribution of patients enrolled in these studies is not known or very few Blacks and Hispanics were included. Hence, the prognostic value of normal stress perfusion imaging in Blacks and Hispanic patients is not well established. Our objective was to determine the incidence of all cause mortality in Blacks and Hispanics with normal myocardial stress perfusion scan and EF. Methods and Results: Retrospective review of 657 patients who had normal SPECT Tc99m sestamibi stress perfusion study utilizing attenuation and scatter correction, with gated SPECT EF ≥45 in year 2000. Blacks 34%, Hispanics 55%. All cause mortality from Social Security Death Index was 22 (3.3%) over at least 36 months period, thus an annual mortality rate of approximately 1.1%. Study population was divided in two groups those alive and those dead. Analysis showed that following characteristics were predictor for increased mortality, older age, diabetes mellitus, High resting heart rate, resting EKG abnormalities, low end point systolic and diastolic pressure. There was no significant difference amongst the two groups in gender, smoking h/o hypertension, resting systolic or diastolic blood pressure, EF by gated SPECT and transient Ischemic dilatation. Characters Alive (N = 635) Dead (N = 22) P value Age 58.3 ± 11.9 65.9 ± 12.8 0.003 Diabetes Mellitus 27% 77% 0.0000003 Resting EKG abn 44% 82% 0.0004 Resting HR 70 ± 14 82 ± 18 0.0004 Endpoint SBP 159 ± 36 137 ± 41 0.007 Endpoint DBP 75 ± 12 67 ± 11 0.002 Conclusions: This study is first of its kind study in an inner city population. The overall mortality in Black and Hispanic patients with normal stress perfusion study with EF≥45 is very low and similar to other Non-Black and Non-Hispanic population.

Clinical value of attenuation correction in stress-only Tc-99m sestamibi SPECT imaging

Background Attenuation artifact remains a substantial limitation to confident interpretation of images and reduces laboratory efficiency by requiring comparison of stress and rest image sets. Attenuation-corrected stress-only imaging has the potential to ameliorate these limitations. Methods and results Ten experienced nuclear cardiologists independently interpreted 90 stress-only electrocardiography (ECG)–gated technetium 99m sestamibi images in a sequential fashion: myocardial perfusion imaging (MPI) alone, MPI plus ECG-gated data, and attenuation-corrected MPI with ECG-gated data. Images were interpreted for diagnostic certainty (normal, probably normal, equivocal, probably abnormal, abnormal, and perceived need for rest imaging). With stress MPI data alone, only 37% of studies were interpreted as definitely normal or abnormal, with a very high perceived need for rest imaging (77%). The addition of gated data did not alter the interpretations. However, attenuation-corrected data significantly increased the number of studies characterized as definitely normal or abnormal (84%, P < .005) and significantly reduced the perceived need for rest imaging (43%, P < .005). These results were confirmed by use of a nonsequential consensus interpretation of three readers. Conclusion Attenuation correction applied to studies with stress-only Tc-99m ECG-gated single photon emission computed tomography images significantly increases the ability to interpret studies as definitely normal or abnormal and reduces the need for rest imaging. These findings may improve laboratory efficiency and diagnostic accuracy.

Acute beta-blockade reduces the extent and severity of myocardial perfusion defects with dipyridamole Tc-99m sestamibi SPECT imaging

Acute beta-blockade reduces the extent and severity of myocardial perfusion defects with dipyridamole Tc-99m sestamibi SPECT imaging

816-3 Interaction of age and gender on risk stratification of diabetic patients with rest/stress ECG-gated Tc-99m sestamibi SPECT imaging

816-3 Interaction of age and gender on risk stratification of diabetic patients with rest/stress ECG-gated Tc-99m sestamibi SPECT imaging

816-2 Risk stratification of diabetic patients with rest/stress ECG-gated Tc-99m sestamibi SPECT imaging: Significance of mild perfusion abnormalities

816-2 Risk stratification of diabetic patients with rest/stress ECG-gated Tc-99m sestamibi SPECT imaging: Significance of mild perfusion abnormalities

Acute beta-blockade reduces the extent and severity of myocardial perfusion defects with dipyridamole Tc-99m sestamibi SPECT imaging

ObjectivesThe goal of this study was to examine the effect of acute beta-blockade on dipyridamole Tc-99m sestamibi myocardial perfusion imaging (DMPI). BackgroundStudies suggest that antianginal drugs may reduce the presence and severity of myocardial perfusion defects with dipyridamole stress. However, there are no data regarding specific drugs. MethodsPatients with catheterization-proven coronary artery disease (CAD) were enrolled in this prospective, double-blind, placebo-controlled study and randomly assigned to DMPI after placebo, low-dose metoprolol (up to 10 mg), and high-dose metoprolol (up to 20 mg). Patients underwent one Tc-99m sestamibi study at rest on a separate day. The interval between DMPI studies was ≤14 days. Images were interpreted by three observers blinded to clinical data using a 17-segment, five-point model. For each image, a summed stress score (SSS), summed rest score (SRS), and summed difference score (SDS) were calculated (SDS = SSS − SRS). Images with an SSS <4 were considered normal. ResultsTwenty-one patients completed all four Tc-99m sestamibi studies. The sensitivity of DMPI for detection of CAD was 85.7% with placebo versus 71.4% with low- and high-dose metoprolol. In comparison with placebo, the SSS was significantly lower (p < 0.05) with low- and high-dose metoprolol (12.0 ± 10.1 vs. 8.7 ± 9.0 and 9.3 ± 10.6, respectively). The SDS also was significantly lower (8.4 ± 8.8 with placebo vs. 5.0 ± 6.7 [p < 0.001] and 5.4 ± 7.9 [p < 0.01] with low- and high-dose metoprolol, respectively). ConclusionsThe presence and severity of CAD may be underestimated in patients receiving beta-blocker therapy undergoing dipyridamole stress myocardial perfusion imaging.