Tc-99m Sestamibi Myocardial Perfusion Imaging Research Articles

Tc-99m Sestamibi Myocardial Perfusion Imaging After Coronary Artery Bypass Grafting for Ischemic Heart Failure

Heart failure (HF), a clinical syndrome most commonly occurring due to ischemic heart disease, causes significant morbidity and mortality. The benefits of revascularization versus medical treatment for ischemic heart failure remain controversial. Thus, we assessed a patient diagnosed with ischemic heart failure before and 3 months after coronary artery bypass grafting by myocardial radionuclide imaging. Findings of Tc-99m sestamibi myocardial perfusion imaging revealed that the degree and area of ischemia were significantly reduced, and the systolic function of the left ventricle improved compared with the preoperative value. This suggests the benefit of revascularization in cases of ischemic heart failure.

Correction of hysteretic respiratory motion in SPECT myocardial perfusion imaging: Simulation and patient studies.

Amplitude-based respiratory gating is known to capture the extent of respiratory motion (RM) accurately but results in residual motion in the presence of respiratory hysteresis. In our previous study, we proposed and developed a novel approach to account for respiratory hysteresis by applying the Bouc-Wen (BW) model of hysteresis to external surrogate signals of anterior/posterior motion of the abdomen and chest with respiration. In this work, using simulated and clinical SPECT myocardial perfusion imaging (MPI) studies, we investigate the effects of respiratory hysteresis and evaluate the benefit of correcting it using the proposed BW model in comparison with the abdomen signal typically employed clinically. The MRI navigator data acquired in free-breathing human volunteers were used in the specially modified 4D NCAT phantoms to allow simulating three types of respiratory patterns: monotonic, mild hysteresis, and strong hysteresis with normal myocardial uptake, and perfusion defects in the anterior, lateral, inferior, and septal locations of the mid-ventricular wall. Clinical scans were performed using a Tc-99m sestamibi MPI protocol while recording respiratory signals from thoracic and abdomen regions using a visual tracking system (VTS). The performance of the correction using the respiratory signals was assessed through polar map analysis in phantom and 10 clinical studies selected on the basis of having substantial RM. In phantom studies, simulations illustrating normal myocardial uptake showed significant differences (P<0.001) in the uniformity of the polar maps between the RM uncorrected and corrected. No significant differences were seen in the polar map uniformity across the RM corrections. Studies simulating perfusion defects showed significantly decreased errors (P<0.001) in defect severity and extent for the RM corrected compared to the uncorrected. Only for the strong hysteretic pattern, there was a significant difference (P<0.001) among the RM corrections. The errors in defect severity and extent for the RM correction using abdomen signal were significantly higher compared to that of the BW (severity=-4.0%, P<0.001; extent=-65.4%, P<0.01) and chest (severity=-4.1%, P<0.001; extent=-52.5%, P<0.01) signals. In clinical studies, the quantitative analysis of the polar maps demonstrated qualitative and quantitative but not statistically significant differences (P=0.73) between the correction methods that used the BW signal and the abdominal signal. This study shows that hysteresis in respiration affects the extent of residual motion left in the RM-binned data, which can impact wall uniformity and the visualization of defects. Thus, there appears to be the potential for improved accuracy in reconstruction in the presence of hysteretic RM with the BW model method providing a possible step in the direction of improvement.

Left ventricular dyssynchrony in patients with end-stage liver disease

BackgroundLimited published data suggested that patients with end-stage liver disease (ESLD) might have “cirrhotic cardiomyopathy,” which could have an earlier stage manifested by mechanical dyssynchrony before left ventricular (LV) dysfunction. Methods and ResultsWe studied consecutive patients with ESLD who had a stress-gated Tc-99m sestamibi myocardial perfusion imaging between 2008 and 2010 prior to liver transplant. Patients with LVEF < 50%, abnormal perfusion, or QRS ≥ 120 ms were excluded. Baseline demographics, co-morbidities, model for ESLD (MELD) score, LV volumes, mass, ejection fraction (EF), and dyssynchrony indices (standard deviation and bandwidth) were extracted. The phase indices were compared to a normal cohort. There were 179 patients with a mean age 53 ± 8 years, LVEF 72 ± 10%. Hepatitis C, non-alcoholic steatohepatitis, and alcohol abuse were the most common cause of liver cirrhosis (40%, 18%, and 14%, respectively). Patients with ESLD had similar standard deviation (14 ± 8° vs 15 ± 6°, P = NS) and bandwidth (41 ± 25° vs 42 ± 14°, P = NS) to the normal cohort. Only four patients (2%) had a standard deviation >27° (mean + 2 SD of the control group). The phase standard deviations and bandwidth similar in patients with MELD scores of ≤10, 11-18, 19-24, and ≥25 (P = NS for both). There was no correlation between the MELD score and standard deviation or bandwidth (r = −0.044 and −0.068, respectively, P = NS for both). Also, there was no correlation between the QTc and dyssynchrony indices. After 1-year follow-up, 22 patients died (12%). The dyssynchrony indices were similar among those who died and those who survived. ConclusionPatients with ESLD and normal EF have no evidence for LV dyssynchrony.

The impact of adenosine pharmacologic stress combined with low-level exercise in patients undergoing myocardial perfusion imaging (BIWAKO adenosine-Ex trial)

The combination of adenosine infusion with low-level exercise has become a common approach for inducing stress during stress myocardial perfusion imaging (MPI). We investigated stress MPI performed by combined low-level exercise and adenosine infusion. This combined protocol can decrease adverse reactions and reduce the effect of scattered rays from the liver. Subjects were clinically referred for a 53-min rest-stress Tc-99m Sestamibi MPI procedure using BIWAKO PROTOCOL. Ninety-eight patients (44.5%) underwent adenosine infusion with ergometer exercise testing and 122 patients (55.5%) underwent adenosine infusion without exercise testing. We evaluated the liver/heart (L/H) uptake ratio, background activity in the upper mediastinum, and adverse reactions. The L/H ratio and background activity were lower in the adenosine-exercise group than in the adenosine-non-exercise group (1.8±0.54 vs. 2.1±0.62, P<0.0056; 43.1±12.2 vs. 61.5±15.4, P<0.0001). The adenosine-exercise group had fewer adverse reactions than the adenosine-non-exercise group (11.2 vs. 19.7%). All of the adverse reactions were minor, with the exception of severe back pain in one case. The incidence of adverse reactions in our study was lower than that in previous studies for unknown reason. Adenosine infusion in combination with low-level exercise seems to result in higher-quality images and fewer adverse reactions than adenosine infusion without exercise. The combined protocol decreases adverse reactions and improves the quality of myocardial perfusion images by decreasing background activity.

Intrathoracic Gastric Activity of Tc-99m Sestamibi in a Patient With Gastric Pull-Up for Esophageal Cancer

A 69-year-old man with remote gastric pull-up was evaluated with a 2-day stress-rest dypiridamole Tc-99m sestamibi myocardial perfusion imaging, where significant tracer uptake was noted in the posterior mediastinum related to enterogastric reflux of sestamibi. These ancillary findings were suggestive of a noncardiac etiology of the patient's atypical chest pain. This case highlights the value of examining the raw projection images for incidental findings that may be present during myocardial perfusion imaging.

Role of Tc-99m sestamibi myocardial perfusion imaging in identifying multiple myeloma

Role of Tc-99m sestamibi myocardial perfusion imaging in identifying multiple myeloma

Etiology and pathophysiology of new-onset heart failure: Evaluation by myocardial perfusion imaging

ObjectiveThe IMAGING in Heart Failure study was a prospective, multi-national trial designed to explore the role of single-photon emission computed tomographic (SPECT) myocardial perfusion imaging (MPI) as an initial investigative strategy in patients hospitalized with new-onset heart failure. MethodsWe recruited 201 patients (age 65.3 ± 14.5 years, 43% women) hospitalized with their first episode of heart failure. Rest/stress gated SPECT Tc-99m sestamibi MPI was performed during or within 2 weeks of the index hospitalization, in addition to standard care. ResultsSPECT MPI revealed a broad range of ejection fractions with preserved systolic function in 36% of patients. Forty-one percent of patients had normal perfusion. In the remaining patients, perfusion abnormalities were predominantly due to prior myocardial infarction, with extensive ischemia seen only in 6%. Among patients who underwent coronary angiography, SPECT performance characteristics revealed excellent negative predictive value (96%) for extensive coronary artery disease (CAD). In multivariable analyses, the extent of perfusion abnormality and advancing age predicted the presence of extensive CAD. ConclusionsThese preliminary data derived from a non-randomized observational cohort suggest potential diagnostic utility of MPI for ischemic LV dysfunction in new-onset HF, and sets the stage for a prospective randomized study to confirm these findings.

Comparison of Automated 4D-MSPECT and Visual Analysis for Evaluating Myocardial Perfusion in Coronary Artery Disease

The aim of this study was to assess the reproducibility and diagnostic performance for coronary artery disease (CAD) of an automated software package, 4D-MSPECT, and compare the results with a visual approach. We enrolled 60 patients without previously known CAD, who underwent dual-isotope rest Tl-201/stress Tc-99m sestamibi myocardial perfusion imaging and subsequent coronary angiography within 3 months. The automated summed stress score (A-SSS), summed rest score (A-SRS) and summed difference score (A-SDS) were obtained using a 17-segment five-point scale model with 4D-MSPECT. For intraobserver and interobserver variability assessment, automated scoring was done by a nuclear medicine physician twice and by a nuclear medicine technologist. The visual summed stress score (V-SSS), summed rest score (V-SRS), and summed difference score (V-SDS) were obtained by consensus of two nuclear medicine physicians. The intraobserver and interobserver agreements of automated segmental scores were excellent. The intraobserver and interobserver summed scores also correlated well. Agreements between visual and automated segmental scores were moderate (weighted kappa of 0.55 and 0.50 for stress and rest images, respectively). Correlations between automated and visual summed scores were high, with correlation coefficients of 0.89, 0.85 and 0.82 for SSS, SRS and SDS, respectively (all p < 0.001). The receiver operating characteristic area under the curve for diagnosis of CAD by V-SSS, V-SDS, A-SSS and A-SDS were 0.78 +/- 0.06, 0.87 +/- 0.05, 0.84 +/- 0.05 and 0.90 +/- 0.04, respectively. A-SDS had better diagnostic performance than A-SSS and V-SSS (p = 0.043 and p = 0.032, respectively), whereas there was no statistically significant difference between A-SDS and V-SDS (p = 0.56). Using V-SDS > or = 2 as a diagnostic threshold, the sensitivity, specificity, and accuracy for CAD were 83.7%, 76.5% and 81.7%, respectively. Using A-SDS > or = 3 as a diagnostic threshold, the sensitivity, specificity, and accuracy for CAD were 79.1%, 82.4% and 80.0%, respectively. In conclusion, the reproducibility of automated semiquantitative analysis with 4D-MSPECT was excellent. The diagnostic performance of automated semiquantitative analysis with 4D-MSPECT was comparable with the visual approach.

Tc-99m sestamibi myocardial perfusion imaging after undisclosed I-131 therapy

Tc-99m sestamibi myocardial perfusion imaging after undisclosed I-131 therapy

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Attenuation correction reveals gender-related differences in the normal values of transient ischemic dilation index in rest-exercise stress sestamibi myocardial perfusion imaging

Transient ischemic dilation (TID) has been established as an important independent marker of severe and extensive coronary artery disease (CAD) in myocardial perfusion imaging (MPI). The accuracy of the TID index is dependent on a well-determined threshold (normal limits) between normal and abnormal values for each study protocol. To date, the effects of neither gender nor attenuation correction (AC) on TID normal limits have been established. Thus, the objectives of this study were to determine if AC processing changes the normal value of the TID index and if there were gender-related differences in the TID index of normal patients who had undergone rest/exercise-stress technetium-99m sestamibi MPI. Seventy-five patients (33 women, 42 men; mean age, 57.7 +/- 11.7 y and 55.9 +/- 10.0 y, respectively) with less than a 5% likelihood of CAD, who had undergone low-dose rest/high-dose exercise-stress Tc-99m sestamibi MPI, were studied. All studies were acquired using simultaneous emission/transmission scans and were corrected for attenuation, scatter, and resolution effects using the ExSPECT II method. Both the AC and non-AC studies were analyzed using the Emory Cardiac Toolbox (ECTb; Syntermed, Inc, Atlanta, Ga) quantitative software. The TID index was calculated automatically as the ratio of stress mean left ventricular volumes to rest mean left ventricular volumes by ECTb. Patients were grouped by gender and the TID indices from AC and non-AC studies were compared. Linear regressions of the TID index and body mass index were analyzed to exclude differences in body size between male and female patients as a confounding factor in gender-related differences in TID. The TID index upper normal limits were calculated as the mean value plus 2 standard deviations (SDs). AC processing did not change the TID index significantly whether the genders were combined or separated (AC TID = 0.97 +/- 0.14 vs non-AC TID = 0.98 +/- 0.12 for all patients). Female patients showed higher mean TID indices than male patients in both AC (1.01 +/- 0.15 vs 0.95 +/- 0.12) and non-AC studies (1.00 +/- 0.15 vs. 0.97 +/- 0.10), but this difference was statistically significant only in AC studies (p = .03). TID indices remained constant across the range of body mass index studied. The TID index upper normal limit was 1.31 for female and 1.18 for male patients. TID normal values for rest/exercise-stress Tc-99m sestamibi MPI are gender-dependent and not affected by AC processing. Thus, diagnosticians should take into account these gender-related differences, as compared with the traditional value generated from mostly male populations, to ensure both men and women have the same overall accuracy of using the TID index in the diagnosis and prognosis of CAD.

Effect of prone position and attenuation correction on test characteristics of myocardial perfusion imaging in female patients with breast shadow artifacts

Background: Anterior wall defects due to breast decrease specificity of myocardial perfusion imaging (MPI) in female patients (pts.). We compared prone position uncorrected (PRN), supine uncorrected (NO AC), and attenuation corrected (AC) MPI for perfusion scores, sensitivity, specificity, and diagnostic accuracy in women. Methods: 68 female pts. (70±12 yrs) with (+) or without (-) left anterior descending (LAD) coronary artery stenosis ≥ 70% underwent rest TL-201/stress Tc-99m sestamibi MPI as follows: NO AC + simultaneous AC. 45/68 pts. also had PRN. All pts. had: breast shadow on the raw data; anterior, anteroseptal, or apical defects in the LAD distribution as per AHA/ASNC position statement; no anterior wall infarct; diagnostic angiography within 30 days of MPI. Summed stress perfusion scores were based on a 5-point/17-segment model, and % myocardium in the LAD territory perfusion defects (% LV) was calculated from the scores. Friedman rank test was used for %LV, and McNemar's test for statistical significance (p<0.05) between tests' results. Results: See Table %LV ALL % LV LAD(−) %LV LAD(+) Sensitivity Sensitivity Accuracy PRN (n = 45) 4% 3% (n = 33) 6% (n = 12) 50% 94% 82% NO AC (n = 68) 6% 4% (n = 46) 9% (n = 22) 86% 61% 68% AC (n = 68) 8% 5% (n = 46) 12% (n = 22) 83% 79% 80% p 0.0001 0.005 0.007 ns 0.001 PRN and AC vs. NO AC 0.02 PRN and AC vs. NO AC Conclusion: %LV was lowest with PRN, and highest with AC MPI. Compared with NO AC, AC and PRN MPI had increased specificity and accuracy but a trend to a lower sensitivity was observed for PRN.

Clinical correlation between increased lung to heart ratio of tecnetium-99m sestamibi and multivessel coronary artery disease

Background: An increased lung to heart ratio (LHR) on thallium-201 (Tl-201) stress myocardial perfusion imaging (MPI) is a predictor of adverse cardiac events and identifies people with extensive coronary artery disease (CAD). The implications of increased LHR in patients undergoing stress technetium-99m (tc-99m) sestamibi are developing. Our aim is to evaluate the relationship between increased LHR and extent of CAD in patients undergoing tc-99m sestamibi MPI. Methods: We reviewed the records and images of 530 consecutive subjects who underwent exercise or adenosine tc-99 m sestamibi MPI. One hundred thirty-two had transient or partially reversible myocardial perfusion defects and 79 (exercise=34, adenosine=45, male=43, female=36, mean age=61 years) of these underwent coronary angiography (study population). The average LHR of these 79 subjects was compared to 79 patients (control population) with normal scans (exercise=50, adenosine=29, male=34, female=45, mean age=60 years). Results: The mean LHR (±SE) in subjects with normal scans was 0.30±0.01. The mean LHR for those with abnormal scans and single vessel CAD who underwent exercise was 0.32±0.01 and pharmacological stress was 0.31±0.01. There was no statistically significant difference between the LHR of those with a normal scan and those with single vessel disease and an abnormal scan. However, there was a statistically significant association between the elevated LHR and multi-vessel CAD. The mean LHR for subjects with multi-vessel CAD with exercise was 0.39±0.01 ( p=0.000) and for adenosine was 0.39±0.02 ( p=0.000). Conclusion: An elevated LHR in patients undergoing exercise or pharmacological tc-99m MPI correlates with multi-vessel CAD.

Clinical correlation between increased lung to heart ratio of tecnetium-99m sestamibi and multivessel coronary artery disease

<h2>Abstract</h2> <i>Background:</i> An increased lung to heart ratio (LHR) on thallium-201 (Tl-201) stress myocardial perfusion imaging (MPI) is a predictor of adverse cardiac events and identifies people with extensive coronary artery disease (CAD). The implications of increased LHR in patients undergoing stress technetium-99m (tc-99m) sestamibi are developing. Our aim is to evaluate the relationship between increased LHR and extent of CAD in patients undergoing tc-99m sestamibi MPI. <i>Methods:</i> We reviewed the records and images of 530 consecutive subjects who underwent exercise or adenosine tc-99 m sestamibi MPI. One hundred thirty-two had transient or partially reversible myocardial perfusion defects and 79 (exercise=34, adenosine=45, male=43, female=36, mean age=61 years) of these underwent coronary angiography (study population). The average LHR of these 79 subjects was compared to 79 patients (control population) with normal scans (exercise=50, adenosine=29, male=34, female=45, mean age=60 years). <i>Results:</i> The mean LHR (±SE) in subjects with normal scans was 0.30±0.01. The mean LHR for those with abnormal scans and single vessel CAD who underwent exercise was 0.32±0.01 and pharmacological stress was 0.31±0.01. There was no statistically significant difference between the LHR of those with a normal scan and those with single vessel disease and an abnormal scan. However, there was a statistically significant association between the elevated LHR and multi-vessel CAD. The mean LHR for subjects with multi-vessel CAD with exercise was 0.39±0.01 (<i>p</i>=0.000) and for adenosine was 0.39±0.02 (<i>p</i>=0.000). <i>Conclusion:</i> An elevated LHR in patients undergoing exercise or pharmacological tc-99m MPI correlates with multi-vessel CAD.

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 (≤60 days) revascularization, were studied. Subsequent nonfatal myocardial infarction and cardiac death were related to perfusion and ECG-gated SPECT ventricular function parameters. Cox proportional hazards regression analysis was used to evaluate the independent predictive value of these parameters, as well as their added utility over clinical and ECG parameters. Patients with abnormal perfusion images had an annual event rate of 5.1% compared with 1.6% for patients with normal images ( P < .001). An abnormal gated SPECT wall motion score was associated with an annual event rate of 6.1% compared with 1.6% for a normal score ( P < .001), and an abnormal left ventricular ejection fraction was associated with an event rate of 7.4% compared with 1.8% for normal patients ( P < .001). Abnormal ECG-gated SPECT results worsened outcome in both patients with normal perfusion images and those with abnormal perfusion images. Cardiac death was predicted by the number of territories with a perfusion defect and an abnormal ejection fraction, whereas myocardial infarction was predicted by the number of territories with a perfusion defect but not by ejection fraction. Conclusions Ventricular function data from ECG-gated SPECT add important prognostic value to data obtained from perfusion imaging alone in predicting adverse cardiac events.

1056-157 Serial testing with rest/stress Tc-99m sestamibi myocardial perfusion imaging: Normal results provide an extended warranty

1056-157 Serial testing with rest/stress Tc-99m sestamibi myocardial perfusion imaging: Normal results provide an extended warranty

816-5 Progression of coronary artery disease in diabetics demonstrated by single isotope rest/stress Tc-99m sestamibi myocardial perfusion imaging: More rapid than nondiabetics?

816-5 Progression of coronary artery disease in diabetics demonstrated by single isotope rest/stress Tc-99m sestamibi myocardial perfusion imaging: More rapid than nondiabetics?

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.

Impact of acute chest pain Tc-99m sestamibi myocardial perfusion imaging on clinical management

Background. Previous studies have demonstrated the high sensitivity and specificity of technetium 99m sestamibi scintigraphy during acute chest pain myocardial perfusion imaging. However, no study has shown that this technique would alter clinical management in practice. Methods and Results. One hundred twenty consecutive patients were injected with Tc-99m sestamibi (22 mCi) during pain; single photon emission computed tomography was performed 1 to 6 hours later. The population included inpatients and those who arrived at the emergency department with chest pain deemed to be at intermediate risk for myocardial ischemia. The requesting physician completed a questionnaire before the study, indicating the likelihood of cardiac disease and proposed management had the test not been available. Follow-up management was evaluated from medical records. There was a 34% reduction in total admissions and 59% in planned admissions to the coronary care unit (P < .001). Conversely, 7 patients had discharge cancelled and 17 required coronary care purely because of abnormal acute rest myocardial perfusion imaging results. Coronary angiography was reduced by 40% in a selected subgroup. Conclusions. In our population, acute rest myocardial perfusion imaging reduced total admissions and altered resource utilization. This may result in more appropriate triage of individual patients in the management algorithm, as well as potential cost savings. (J Nucl Cardiol 2002;9:257-62.)

Improved Cardiac Iodine-123 Metaiodobenzylguanidine Accumulation After Drug Therapy in a Patient With Parkinson's Disease

A 72-year-old woman with Parkinson's disease and autonomic dysfunction underwent I-123 MIBG cardiac imaging to study sympathetic neuronal integrity. This revealed a defect in the infero-posterior wall. Tc-99m sestamibi myocardial perfusion imaging revealed no abnormalities. On follow-up I-123 MIBG SPECT, the defect was less prominent and the parkinsonian symptoms were ameliorated by drug therapy. Cardiac I-123 MIBG imaging may be a promising new method for evaluating drug therapy in patients with Parkinson's disease.