ECG-gated Myocardial Perfusion SPECT Research Articles

Impact of early post-stress 99mTc sestamibi ECG-gated SPECT myocardial perfusion imaging on the detection ofischemic LV dyssynchrony: an early step in the stunning cascade.

Transient alterations in ventricular conduction and synchronized cardiac performance have been reported in experimental models of myocardial ischemia. In post-stress 99mTc-sestamibi-gated-SPECT myocardial perfusion imaging (MPI), the time elapsed between tracer injection and image acquisition could influence the detection of ischemic left ventricular mechanical dyssynchrony (LVMD). We aimed at evaluating whether early vs. delayed post-stress MPI improve ischemic LVMD detection using the phase analysis parameters standard deviation (SD) and histogram bandwidth (HB) and to assess the correlation between stress-induced changes in SD and HB and other functional parameters. We prospectively studied 32 control subjects (Group-1) and 60 ischemic patients (Group-2). Stress-induced changes were calculated as stress minus rest (Δ). LVMD was defined as post-stress increases of either SD or HB. Group-2 showed higher ΔSD and ΔHB in early than in delayed images: early ΔSD: 1.63 (-0.37 to 4.83) vs. delayed ΔSD: -0.39 (-3.82 to 1.74); early ΔHB: 2.50 (-4 to 12) vs. ΔHB delayed: -4 (-15.75 to 4), all p < 0.01. ΔSD and ΔHB correlated linearly with ΔLV-ejection-fraction (EF) and ΔLV-end systolic-volume (ESV) in early images, all p < 0.01. Early images detected LVMD in more patients than delayed scans (78% vs. 38%; p < 0.01) All patients with LVEF drop in early post-stress evaluation had LVMD. Early post-stress images improve ischemic LVMD detection. Ischemic LVEF and LVESV changes correlate with ΔSD and ΔHB.

Development of Novel Algorithm for Quantitative Assessment of Left Ventricular Dyssynchrony Evaluated by ECG-gated Myocardial Perfusion SPECT Imaging

Development of Novel Algorithm for Quantitative Assessment of Left Ventricular Dyssynchrony Evaluated by ECG-gated Myocardial Perfusion SPECT Imaging

Effect of patient positioning on the evaluation of myocardial perfusion SPECT

BackgroundECG-gated SPECT myocardial perfusion imaging is usually acquired in supine position. However, some patients are not comfortable in this position for a variety of personal or medical reasons. Our aim was to investigate the effect of patient positioning on quantitative SPECT imaging results using normal supine database. Methods55 patients (mean age 58.5 ± 8.3 years) were enrolled in this prospective study. Each patient had a pair of ECG-gated stress SPECT myocardial perfusion images acquired on two gamma cameras: one in supine position and the other in upright sitting position. Left ventricular (LV) ejection fraction (EF), end-diastolic (ED), and end-systolic (ES) left ventricular volumes (V), LV mass, summed stress perfusion defect score (SSS), and total severity score (TSS) were calculated automatically relative to a supine normal reference database. ResultsThere were no significant differences in LVEF using the two cameras (0.65 ± 0.08 vs. 0.66 ± 0.10; P > 0.1). However, EDV, ESV, and LV mass were significantly smaller in sitting position than in supine position (89 vs. 80 ml; 33 vs. 29 ml and 115 vs. 109 ml, respectively, all P < 0.0001). On the other hand, SSS and TSS were significantly higher in sitting position than in supine position (5.16 vs. 8.73 and 166.82 vs. 288.27, both P < 0.0001). Overall, more studies in sitting position were interpreted as abnormal than in supine position (P < 0.05). ConclusionPatient positioning has a significant impact on quantitative gated SPECT imaging results. Using a supine normal reference database, SSS and TSS were larger in sitting position than in supine position. Thus, for imaging in sitting position, separate normal limits are required.

Prognostic impact of reducing myocardial ischemia identified using ECG-gated myocardial perfusion SPECT in Japanese patients with coronary artery disease: J-ACCESS 4 study

AimWhether myocardial ischemia identified using myocardial perfusion imaging (MPI) can be an alternative target of coronary revascularization to reduce the incidence of cardiac events remains unclear. Methods and resultsThis multicenter, prospective cohort study aimed to clarify the prognostic impact of reducing myocardial ischemia. Among 494 registered patients with possible or definite coronary artery disease (CAD), 298 underwent initial pharmacological stress 99mTc-tetrofosmin MPI before, and eight months after revascularization or medical therapy, and were followed up for at least one year. Among these, 114 with at least 5% ischemia at initial MPI were investigated. The primary endpoints were cardiac death, non-fatal myocardial infarction and hospitalization for heart failure. Ischemia was reduced ≥5% in 92 patients. Coronary revascularization reduced ischemia (n = 89) more effectively than medical therapy (n = 25). Post-stress cardiac function also improved after coronary revascularization. Ejection fraction significantly improved at stress (61.0% ± 10.7% vs. 65.4% ± 11.3%; p < 0.001) but not at rest (67.1% ± 11.3% vs. 68.3% ± 11.6%; p = 0.144), among patients who underwent revascularization. Rates of coronary revascularization and cardiac events among the 114 patients were significantly higher (13.6%, p = 0.035) and lower (1.1% p = 0.0053), respectively, in patients with, than without ≥5% ischemia reduction. Moreover, patients with complete resolution of ischemia at the time of the second MPI had a significantly better prognosis. ConclusionsReducing ischemia by ≥5% and the complete resolution of ischemia could improve the prognosis of patients with stable CAD.

Assessment of Left Ventricular Diastolic Function Using ECG-gated Myocardial Perfusion SPECT in Small Heart: Comparison with Ultrasound Echocardiography

Assessment of left ventricular (LV) diastolic function is important because it is possible to detect early sign of myocardial ischemia by this assessment. The purpose of this study was to compare between electrocardiogram (ECG) -gated myocardial perfusion single photon emission computed tomography (G-SPECT) and ultrasound echocardiography in assessment of LV diastolic function in the small heart (SH). The study population consisted of 144 patients who underwent both G-SPECT and ultrasound echocardiography. Peak filling rate (PFR), one-third mean filling rate (1/3 MFR) and the ratio of time to PFR to the RR interval (TPFR/RR) were calculated by quantitative gated SPECT (QGS) and heart risk view-F (HRV-F). Peak early mitral annular velocity (e') was used as the reference standard of LV diastolic function. There were 33 patients with end-systolic volume (ESV) of ≤10 ml (SH10), 51 patients with ESV of 11-20 ml (SH 20) and 60 patients with ESV of >20 ml (normal-sized heart: NH). In SH10, PFR calculated by QGS was not correlated with e'. However, that by HRV-F was significantly correlated with e' (r=0.47, p=0.006). On the other hand, 1/3 MFR and TPFR/RR calculated by QGS and HRV-F were not correlated with e' in SH10 and SH20. PFR, 1/3 MFR and TPFR/RR calculated by QGS and HRV-F were correlated with e' in NH.

Left ventricular phase entropy: Novel prognostic predictor in patients with dilated cardiomyopathy and narrow QRS

BackgroundThe prognostic impact and pathophysiology of global left ventricular mechanical dyssynchrony (LVMD), namely mechanical dyssynchrony of whole left ventricle, as assessed by phase analysis of electrocardiographically gated (ECG-gated) myocardial perfusion SPECT has not been clearly elucidated in patients with dilated cardiomyopathy (DCM) and narrow QRS complex (<120 ms). Methods and ResultsForty-six patients with DCM underwent ECG-gated myocardial 99mTc-sestamibi perfusion SPECT and endomyocardial biopsy. LV phase entropy was automatically calculated using a phase analysis of ECG-gated myocardial perfusion SPECT. The patients were divided into two groups according to the median phase entropy value: low-phase entropy (<0.61) (N = 23: LE group) and high-phase entropy (≥0.61) (N = 23: HE group). In the Kaplan-Meier survival analysis, the event-free survival rate was significantly lower in the HE group (log-rank P = 0.015). Moreover, high-phase entropy was an independent predictor of adverse cardiac events (hazard ratio, 5.77%; 95% confidence interval, 1.02-108.32; P = 0.047). Interestingly, the mRNA expression levels of sarcoplasmic reticulum Ca2+-ATPase (SERCA2a) in endomyocardial biopsy specimens were significantly lower in the HE group (P = 0.015). ConclusionLV phase entropy, which may reflect impairment of Ca2+ handling caused by decreased SERCA2a mRNA levels, is a novel prognostic predictor in patients with DCM and narrow QRS complex.

Influence of respiratory motion correction on quantification of myocardial perfusion SPECT

BackgroundRespiratory-related cardiac motion could have considerable effects on myocardial perfusion imaging, leading to misinterpretation of the images. In this study, we examined the influence of respiratory correction on ECG-gated myocardial perfusion SPECT (RC-GSPECT) concerning regional myocardial perfusion and function. Materials and MethodsUsing the NCAT phantom, a typical torso phantom was generated. SimSET, a Monte Carlo simulator, was used to image the photon emerging from the phantom. Twenty-six patients underwent a 2-day stress-rest ECG-gated myocardial perfusion SPECT (GSPECT) imaging. A separate study was also performed by simultaneous respiratory and cardiac triggering with the real-time position management (RPM) for respiratory correction (RC). ResultsIn simulation study, count density in the inferior and inferoseptal walls increased in the lower bin of the respiratory cycle. On the other hand, there was a higher correlation between RC-GSPECT and echocardiography for left ventricular ejection fraction (LVEF) (r = 0.95, P < .01 vs r = 0.88, P < .01 for GSPECT). ConclusionWe proposed a new approach for respiratory and cardiac-gated SPECT to eliminate respiratory motion artifacts. RC-GSPECT is a feasible method in MPI studies and may play an important role to improve the quality of MPI images, particularly in the inferior wall.

Bilateral coronary artery to pulmonary trunk fistulae detected by coronary angiography and evaluated by ECG-gated SPECT myocardial perfusion imaging: report of two cases.

Coronary artery fistulae (CAF) are anomalies related to coronary artery abnormal termination. This is a very rare congenital malformation accounting for about 0.2-0.4% of congenital cardiac anomalies, but in some patients it can be haemodynamically important. Single-photon emission computed tomography or positron emission tomography myocardial perfusion imaging (MPI) using radioactive agents is widely used in clinical practice for cardiac ischaemia detection as a very sensitive and non-invasive tool. We are going to present 2 patients with bilateral CAFs to the pulmonary trunk without signs of the rest or stress ischaemia in MPI.

Rationale and design of J-ACCESS 4: Prognostic impact of reducing myocardial ischemia identified using ECG-gated myocardial perfusion SPECT in Japanese patients with coronary artery disease

BackgroundThe findings of our recent study entitled, “Japanese Assessment of Cardiac Events and Survival Study by Quantitative Gated SPECT (J-ACCESS)” showed that myocardial perfusion single photon emission computed tomography (MPS) can detect coronary artery disease (CAD) and help to predict future cardiac events in patients with suspected or extant CAD. However, the extent of the benefit conferred by percutaneous coronary intervention (PCI) as an initial management strategy compared with optimal medical therapy remains controversial. Little evidence supports the notion that myocardial ischemia identified using MPS is an alternative target of coronary revascularization to reduce the likelihood of developing cardiac events. MethodsThe multicenter, prospective cohort J-ACCESS 4 study aims to clarify the prognostic impact of reducing myocardial ischemia determined using electrocardiogram-gated MPS in Japanese patients with coronary artery disease. We started to register patients in J-ACCESS 4 at 74 facilities during June 2012 and will continue to do so until December 2013 or until the cohort comprises 500 patients who will participate in the study from one month before, until two months after stress/rest MPS assessment. Imaging data, the background of the patients including coronary risk factors and treatment before MPS assessments will be analyzed. The patients will undergo coronary revascularization within two months after MPS and/or receive appropriate medical therapy. The second stress/rest MPS will be performed from 4 to 10 months after coronary revascularization or registration. They will be followed up for over one year after the second MPS assessment. The primary endpoints will be cardiac death, sudden death of unknown cause, non-fatal myocardial infarction, and hospitalization for heart failure. The secondary endpoints will comprise death due to all causes including non-cardiac death and any cardiovascular events.This study will be completed in 2015. Here, we describe the design of the J-ACCESS 4 study.

Novel algorithm for quantitative assessment of left ventricular dyssynchrony with ECG-gated myocardial perfusion SPECT: useful technique for management of cardiac resynchronization therapy

Cardiac resynchronization therapy (CRT) is the established treatment for patients with chronic and severe heart failure, and it has been reported that the presence of left ventricular (LV) dyssynchrony is one of the most important factors which predict positive response of this therapy. In the present study, we developed new software algorithm for quantitative assessment of LV dyssynchrony from ECG-gated myocardial perfusion SPECT (GMPS), and evaluated its utility for the management of CRT. Thirty-three patients with chronic severe heart failure were studied. GMPS was performed with 16 frame per-cardiac-cycle before and 6 months after CRT and LV end-diastolic volume, end-systolic volume (LVESV), ejection fraction (LVEF) were calculated by QGS software. We generated the time-activity curve per-cardiac-cycle in 4 myocardial segments by Fourier transform curve-fitting of the 16 serial count values, and measured the time from R-wave to the maximum-count point [time to end-systole (TES)] in each. For the evaluation of the degree of LV dyssynchrony, we used the maximum difference in TES (ΔTES) among the 4 segments which corrected for R-R time as dyssynchrony index (DI). Moreover, DI at baseline evaluated by GMPS was compared with the echocardiographic index of LV dyssynchrony; maximum difference of time to peak velocity (ΔTPV) evaluated by tissue Doppler imaging (TDI). DI before CRT showed a significant correlation with the LV function, such as LVEF, LVESV (DI vs. LVEF; r = 0.57, P < 0.0001. DI vs. LVESV; r = 0.64, P < 0.0001). The study subjects were divided into 2 groups, responder group (R-Gp) with LVEF increase >10% or LVESV decrease >10% and non-responder group (NR-Gp). DI before CRT was significantly larger in R-Gp than in NR-Gp (25.9 ± 22.2 vs. 10.8 ± 8.9, P = 0.01). In R-Gp, DI showed a significant decrease after CRT (25.9 ± 22.2 → 13.6 ± 10.9, P < 0.05). DI at baseline measured by GMPS correlated significantly with ΔTPV at baseline measured by TDI (r = 0.38, P < 0.05). This new algorithm for the estimation of LV dyssynchrony might be comparable to TDI, and contributes to the prediction and the evaluation for the response of CRT.

Impact of image reconstruction on phase analysis of ECG-gated myocardial perfusion SPECT studies

Phase analysis (SyncTool) has been developed to assess left-ventricular (LV) dyssynchrony from gated myocardial perfusion single-photon emission computed tomography (GSPECT) studies. Conventionally, GSPECT data are reconstructed using filtered backprojection (FBP). This study is intended to determine the impact of various iterative reconstruction methods on SyncTool. Thirty consecutive patients, acquired using a Philips CardioMD system, were enrolled in this study. The GSPECT data were reconstructed using FBP, maximum likelihood expectation maximization (MLEM), MLEM with three-dimensional resolution recovery (Astonish), MLEM with Vantage attenuation correction (AC), and MLEM with Vantage AC and three-dimensional Monte Carlo-based scatter correction (ACSC), respectively. The reconstructed data were then submitted to SyncTool to measure LV dyssynchrony (phase standard deviation and histogram bandwidth). The paired t-test was used to compare the LV dyssynchrony indices given by MLEM, Astonish, AC, and ACSC, respectively, with those given by the FBP. No statistical significance was observed for any comparison between iterative reconstruction methods and the FBP. Reconstruction methods have insignificant impact on the LV dyssynchrony indices, indicating that the standard FBP reconstruction is sufficient for accurate phase analysis, supporting the widespread clinical use of SyncTool in measuring LV dyssynchrony.

Quantitative Assessment of Dyssynchrony Using ECG-Gated SPECT Myocardial Perfusion Imaging Prior to and Following Cardiac Resynchronization Therapy

Cardiac resynchronization therapy (CRT) assists patients with advanced heart failure (HF) by improving left ventricular (LV) dyssynchrony, but there are significant numbers of non-responders, 1 reason being that the QRS duration is used as the only surrogate determinant of mechanical dyssynchrony, so an effective indicator of LV dyssynchrony is required. The present patient, who had HF, underwent CRT and showed clinical improvement with marked LV reverse remodeling. The regional contraction timing in the LV was assessed with software developed in an application on ECG-gated SPECT myocardial perfusion imaging that depicts the time-volume relationship of the segmented ventricular myocardium and the dispersion of time to end-systole as an expression of dyssynchrony. It was reduced in this patient following CRT. Discordance of systole in regional myocardial segments may present as mechanical dyssynchrony in the LV and could be used as an alternative to QRS duration. Quantitative assessment of dyssynchrony may be possible using this novel method, but further evaluation of the methodology is required.

Relationship between left ventricular function and wall motion synchrony in heart failure assessed by ECG-gated myocardial perfusion SPECT

To confirm the relationship between left ventricular (LV) function and wall motion synchrony, and to identify the difference of synchrony between an ischemic heart disease (IHD) patient group and other heart disease (OHD) patient group among classified groups in heart failure, systolic, and diastolic parameters were compared using electrocardiograph-gated single-photon emission computed tomography. Twenty IHD and 30 OHD patient groups, comprised New York Heart Association functional class I-III (IHD1-3 and OHD1-3), and 15 controls were examined. The LV functions (ejection fraction, EF; peak-filling rate, PFR) and synchrony, which was estimated from the time lag between the earliest and latest regional systolic or diastolic temporal parameters (maximum difference of regional time to end-systole, MD-TES, or maximum difference of regional time to peak filling, MD-TPF), were compared. The LV function correlated with its synchrony in IHD and OHD (EF vs. MD-TES: r = -0.86, P = 1.3 x 10(-6) in IHD and r = -0.69, P = 2.8 x 10(-5) in OHD. PFR versus MD-TPF: r = -0.67, P < 0.002 in IHD and r = -0.63, P < 0.0002 in OHD). Dyssynchronous normal EF was observed in three IHD (15%) and six OHD (20%). Dyssynchronous normal PFR was observed in six IHD (30%) and six OHD (20%). MD-TES was significantly smaller in control group (CG) than in IHD3 and OHD3 (P < 0.005), and in IHD1 than in IHD3 and OHD3 (P < 0.05). MD-TPF was significantly smaller in CG than in IHD2, IHD3, and OHD3 (P < 0.05). However, there was no significant difference between LV synchrony in IHD and OHD, or among LV synchrony of the same functional classes between these two groups. This study confirms that LV function is correlated with wall motion synchrony. No statistically significant difference was confirmed in wall motion synchrony between IHD and OHD. However, dyssynchrony appears in the patients without apparent global LV dysfunction. This feature may facilitate identification of synchronous disorder in HF patients with preserved global LV function. It is expected that detection of such a disorder may lead to the initiation of appropriate treatments for early stage HF and prevent its progression.

Temporal resolution of multiharmonic phase analysis of ECG-gated myocardial perfusion SPECT studies

Multiharmonic phase analysis (MHPA) was developed to assess left-ventricular dyssynchrony from gated myocardial perfusion single-photon emission computed tomography (GSPECT) studies. This study was intended to determine the temporal resolution of MHPA. A reference normal GSPECT study with 128 frames/cycle was simulated using NCAT, a nonuniform rational B-splines-based cardiac torso phantom. It was shifted in the time domain to insert phase delays. Realistic GSPECT studies (8 or 16 frames/cycle) were then obtained by down-sampling the reference and shifted studies. All GSPECT projections were generated with attenuation, scatter, collimator blurring, and Poisson noise. Seventeen regional phases were calculated from the GSPECT reconstructions (filtered back-projection without compensation for physical factors), using linear interpolation for the reference study, and MHPA for the realistic studies. Comparing the regional phases between the realistic studies without and with shifts determined whether MHPA could identify certain phase delays. When there were enough counts/pixel (>10 counts/pixel), MHPA with either 1, 2, or 3 harmonics could resolve a phase difference of 5.6 degrees , corresponding to 1/64 of the cardiac cycle. With clinically equivalent counts, the temporal resolution of MHPA is 1/64 of a cardiac cycle. Achieving this high temporal resolution from data with low temporal resolution demonstrates the benefit of replacing discrete points with continuous harmonic functions.

Regional left-ventricular diastolic wall motion assessed by a new program for ECG-gated myocardial perfusion SPECT in early-stage heart failure

We developed a new program for gated single-photon emission computed tomography to estimate regional left-ventricular (LV) wall motion. We classified and graded diastolic wall motion, and compared its grading with global LV functions. Forty New York Heart Association functional class I (NYHA class I) patients and 15 control subjects were examined. The global time to peak filling and the regional diastolic wall motion synchrony, as estimated by the time lag between the earliest and latest regional peak filling, were evaluated. Using the control group's mean + 2 SD, diastolic wall motions were classified into four subsets: globally normal and regionally synchronous, globally normal but regionally dyssynchronous, globally prolonged and regionally dyssynchronous, and globally prolonged but regionally synchronous. These subsets were graded 0 to 3, respectively. Grade 0 was defined as normal. Grading was compared with global LV functions. Although 67.5% of patients demonstrated abnormal motion, the global diastolic parameter less frequently detected an abnormality (22.5% to 32.5%). Grading correlated with the first-third filling fraction (Spearman's rank correlation coefficient [rs] = -0.74, P = 3.8 x 10(-6)) and the first-third filling rate (rs = -0.49, P < .005). Regional diastolic wall motion abnormality was frequently detected even in early-stage heart failure. Grading reflected early diastolic dysfunction.

Assessment of Left Ventricular Dyssynchrony During Development of Heart Failure by a Novel Program Using ECG-Gated Myocardial Perfusion SPECT

A novel program, "cardioGRAF", has been developed to analyze regional left ventricular (LV) systolic/diastolic function and dyssynchrony, so the present study aimed to use it confirm the presence of LV dyssynchrony, and to correlate LV function and dyssynchrony with plasma B-type natriuretic peptide (BNP) levels during the early to advanced stages of heart failure (HF). Fourteen control subjects (G-C) and 50 patients (New York Heart Association functional class I: G-1, 21 patients; class II: G-2, 15 patients; and class III: G-3, 14 patients) were examined by ECG-gated myocardial perfusion single-photon emission computed tomography, using the new index of dyssynchrony, maximal difference (MD), which is the difference between the earliest and latest temporal parameters among 17 segments. First-third filling rate (FR) and the MD of time to peak FR revealing diastolic dyssynchrony were significantly different between G-C subjects and G-1 patients. Ejection fraction, peak ejection rate, peak FR, MD of time to end-systole, and MD of time to peak ejection rate were significantly correlated with plasma BNP levels. Diastolic dyssynchrony was demonstrated even in the early stage of HF, but, although not correlated with the plasma BNP level, systolic dyssynchrony might affect it.

Incremental Prognostic Value of Cardiac Function Assessed by ECG-Gated Myocardial Perfusion SPECT for the Prediction of Future Acute Coronary Syndrome

The prognostic value of ECG-gated rest 201Tl/stress 99mTc-tetrofosmin myocardial perfusion single-photon emission computed tomography for the prediction of acute coronary syndrome (ACS: myocardial infarction (MI) and unstable angina (UA)) and the implications of ejection fraction (EF) has not yet been defined in Japanese. The 1,895 patients were followed up for the occurrence ACS. The mean follow-up interval was 26.9+/-15.5 months. The 142 patients with revascularization within 60 days were censored. Summed stress score (SSS) and summed difference score (SDS) were calculated. The 19 MI and 29 UA occurred (1.1% and 1.6%, respectively). Univariate Cox analysis showed that hypertension (Wald 5.09, p<0.05), poststress EF (Wald 10.9, p<0.01), SSS (Wald 12.4, p<0.001) and SDS (Wald 18.7, p<0.001) were significant predictors of ACS. Multivariate Cox analysis showed that hypertension (Wald 4.27, p<0.05) and SDS (Wald 8.59, p<0.01) were independent predictors. When multiple clinical risk factors (number of coronary risk factors > or =2), significant ischemia (SDS > or =4) and low EF (EF <45%) were applied to multivariate Cox analysis, the combination of significant ischemia and low EF showed the highest predictive value (Wald 11.9; p<0.001) for future ACS. Poststress EF added incremental prognostic value for the prediction of ACS.

Caracterização do aneurisma apical da cardiopatia chagásica crônica mediante uso de corregistro de imagens cintilográficas

.Recent clinical trials have shown that the presence of this cardiac lesion is an independent risk factor for cardioembolic stroke in patients with chronic Chagas’ heart disease 3-5 . Therefore, early detection of the aneurysm using several diagnostic imaging methods is clinically relevant because of its therapeutic implications. ECG-gated SPECT myocardial perfusion imaging has been recently validated for assessing left ventricular function, and is now widely used 6 . Visual analysis of tomographic slices displayed in cine mode allows the identification of dyskinetic areas, including left ventricle aneurysms, associated with ischemic heart disease 7 . Nevertheless, while many Chagasic patients undergo myocardial perfusion imaging due to symptoms suggestive of myocardial ischemia, there is no report on characterization of the apical aneurysm of chronic Chagas’ disease by gated-SPECT. Multi-gated blood pool SPECT (MUGA-SPECT), which produces images of the ventricular cavity, and gated-SPECT (which produces images of the ventricular walls) provide complementary information for better characterization of this form of ventricular lesion in chronic Chagas’ heart disease. Recent computational techniques allow these images to be aligned and co-registered, with simultaneous visualization of these structures. This report describes the anatomical and functional characteristics of apical aneurysms in chronic Chagas’ heart disease patients using different modalities of three-dimensional cardiac image co-registration, most specifically, myocardial perfusion and labeled blood pool images.

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