Planar imaging versus gated blood-pool SPECT for the assessment of ventricular performance: a multicenter study.

Gated blood-pool SPECT (GBPS), inherently 3-dimensional (3D), has the potential to replace planar equilibrium radionuclide angiography (ERNA) for computation of left ventricular ejection fraction (LVEF), analysis of regional wall motion (RWM), and analysis of right heart function. The purpose of this study was to compare GBPS and ERNA for the assessment of ventricular function in a large, multicenter cohort of patients. METHODS: One hundred seventy-eight patients referred in the usual manner for nuclear medicine studies underwent ERNA followed by GBPS. Each clinical site followed a GBPS acquisition protocol that included 180 degrees rotation, a 64 by 64 matrix, and 64 or 32 views using single- or double-head cameras. Transverse GBPS images were reconstructed with a Butterworth filter (cutoff frequency, 0.45-0.55 Nyquist; order, 7), and short-axis images were created. All GBPS studies were processed with a new GBPS program, and LVEF was computed from the isolated left ventricular chamber and compared with standard ERNA LVEF. Reproducibility of GBPS LVEF was evaluated, and right ventricular ejection fraction (RVEF) was computed in a subset of patients (n = 33). Using GBPS, RWM and image quality from 3D surface-shaded and volume-rendered cine displays were evaluated qualitatively in a subset of patients (n = 30). RESULTS: The correlation between GBPS LVEF and planar LVEF was excellent (r = 0.92). Mean LVEF was 62.2% for GBPS and 54.1% for ERNA. The line of linear regression was GBPS LVEF = (1.04 x ERNA LVEF) + 6.1. Bland-Altman plotting revealed an increasing bias in GBPS LVEF with increasing LVEF (Y = 0.13x + 0.61; r = 0.30; mean difference = 8.1% +/- 7.0%). Interoperator reproducibility of GBPS LVEF was good (r = 0.92). RVEF values averaged 59.8%. RWM assessment using 3D cine display was enhanced in 27% of the studies, equivalent in 67%, and inferior in 7%. CONCLUSION: GBPS LVEF was reproducible and correlated well with planar ERNA. GBPS LVEF values were somewhat higher than planar ERNA, likely because of the exclusion of the left atrium.     

Effect of temporal sampling on evaluation of left ventricular ejection fraction by means of thallium-201 gated SPET: comparison of 16- and 8-interval gating, with reference to equilibrium radionuclide angiography

Gated myocardial single-photon emission tomography (SPET) allows the evaluation of left ventricular ejection fraction (LVEF), but temporal undersampling may lead to systolic truncation and ejection fraction underestimation. The aim of this study was to evaluate the impact of temporal sampling on thallium gated SPET LVEF measurements. Fifty-five consecutive patients (46 men, mean age 62±12 years) with a history of myocardial infarction (anterior 31, inferior 24) were studied. All patients underwent equilibrium radionuclide angiography (ERNA) and gated SPET 4 h after a rest injection of 185 MBq (5 mCi) of thallium-201 using either 8-interval (group 1, n=25) or 16-interval gating (group 2, n=30). In group 2, gated SPET acquisitions were automatically resampled to an 8-interval data set. Projection data were reconstructed using filtered back-projection (Butterworth filter, order 5, cut-off 0.20). LVEF was then calculated using commercially available software (QGS). A higher correlation between gated SPET and ERNA was obtained with 16-interval gating (r=0.94) compared with the resampled data set (r=0.84) and 8-interval gating (r=0.71). Bland-Altman plots showed a dramatic improvement in the agreement between gated SPET and ERNA with 16-interval gating (mean difference: –0.10%±5%). Using multiple ANOVA, temporal sampling was the only parameter to influence the difference between the two methods. When using 8-interval gating, gated SPET LVEF was overestimated in women and underestimated in men (ERNA minus gated SPET = –4.0%±9.6% in women and 3.6%±7.6% in men, P=0.01). In conclusion, 16-interval thallium gated SPET offered the best correlation and agreement with ERNA, and should be preferred to 8-interval gated acquisition for LVEF measurement.     

Effect of temporal sampling on evaluation of left ventricular ejection fraction by means of thallium-201 gated SPET: comparison of 16- and 8-interval gating, with reference to equilibrium radionuclide angiography

Gated myocardial single-photon emission tomography (SPET) allows the evaluation of left ventricular ejection fraction (LVEF), but temporal undersampling may lead to systolic truncation and ejection fraction underestimation. The aim of this study was to evaluate the impact of temporal sampling on thallium gated SPET LVEF measurements. Fifty-five consecutive patients (46 men, mean age 62+/-12 years) with a history of myocardial infarction (anterior 31, inferior 24) were studied. All patients underwent equilibrium radionuclide angiography (ERNA) and gated SPET 4 h after a rest injection of 185 MBq (5 mCi) of thallium-201 using either 8-interval (group 1, n=25) or 16-interval gating (group 2, n=30). In group 2, gated SPET acquisitions were automatically resampled to an 8-interval data set. Projection data were reconstructed using filtered back-projection (Butterworth filter, order 5, cut-off 0.20). LVEF was then calculated using commercially available software (QGS). A higher correlation between gated SPET and ERNA was obtained with 16-interval gating (r=0.94) compared with the resampled data set (r=0.84) and 8-interval gating (r=0.71). Bland-Altman plots showed a dramatic improvement in the agreement between gated SPET and ERNA with 16-interval gating (mean difference: -0.10%+/-5%). Using multiple ANOVA, temporal sampling was the only parameter to influence the difference between the two methods. When using 8-interval gating, gated SPET LVEF was overestimated in women and underestimated in men (ERNA minus gated SPET = -4.0%+/-9.6% in women and 3.6%+/-7.6% in men, P=0.01). In conclusion, 16-interval thallium gated SPET offered the best correlation and agreement with ERNA, and should be preferred to 8-interval gated acquisition for LVEF measurement.     

Gated-SPECT equilibrium radionuclide angiography in right ventricular assessment of patients with repaired tetralogy of Fallot

BACKGROUND: The long-term prognosis of patients with tetralogy of Fallot (TF) who have undergone repair is determined by right ventricular dilatation resulting from residual pulmonary insufficiency. We have studied the values of right and left ventricle systolic function obtained by gated single photon emission computed tomography (SPECT) equilibrium radionuclide angiography (ERNA) in these patients. METHODS: A study population of 62 patients with surgically repaired TF underwent gated-SPECT ERNA to determine ejection fraction of the right and left ventricle and dimensions of the right ventricle and pulmonary infundibulum. Results were compared with those of a group of 11 patients without heart disease. RESULTS: RVEF (34% vs. 40%, P=0.02) and LVEF (49% vs. 54%, P=0.03) were significantly lower in patients with TF than in the control group. The RVEF and LVEF variation coefficients were 9% and 6.2%, respectively. Volumes of the right ventricle (P=0.003) were significantly greater than those of the control group, although variation coefficients were 15%. CONCLUSIONS: Gated-SPECT ERNA is a non-invasive method of assessing ejection fraction in patients with repaired TF. In these patients, the ejection fraction is decreased in both ventricles, whereas size of the right ventricle is significantly increased. Reproducibility of the RVEF calculation is good, but in the case of volumes it is suboptimal.     

Comparison of radionuclide ventriculography using SPECT and planar techniques in different cardiac conditions

PURPOSE: Accurate assessment of ventricular function is required to optimize therapeutic management of cardiac diseases. The aim of this study was to correlate planar equilibrium multigated acquisition (MUGA) with tomographic ventriculography (SPECT) in patients with diverse volumes and wall motion abnormalities. METHODS: Eighty-three studies in 80 patients (56+/-14 years; 56% women) were classified according to ventricular dilation, wall motion abnormalities and systolic dysfunction. Left and right ventricular ejection fraction (LVEF and RVEF) and end-diastolic and end-systolic left ventricular volumes (EDV and ESV) were obtained using a commercial QBS program for SPECT. On planar acquisition, LVEF and RVEF were obtained using standard techniques and volumes were determined using the count-based method, without blood sampling. RESULTS: A. Total group: With the planar method, LVEF was 44+/-17%, RVEF 42+/-13%, left EDV 147+/-97 ml (range 31-487 ml) and left ESV 93+/-85 ml (range 15-423 ml); with SPECT the corresponding values were 40+/-20%, 49+/-16%,131+/-95 ml and 91+/-89 ml, respectively (p=NS for all but RVEF). Linear correlation was 0.845 for LVEF, 0.688 for RVEF, 0.927 for left EDV and 0.94 for left ESV, with good intra-class correlation. B. Subgroups: Global and intra-class correlations between planar imaging and SPECT were high for volumes, RVEF and LVEF in all subgroups, except in patients with normal wall motion and function, who showed smaller volumes with SPECT. The group with diffuse wall motion abnormalities had a lower EDV on SPECT. In the abnormal left ventricle, RVEF was higher with SPECT. CONCLUSION: Good correlation and agreement exist between SPECT and planar MUGA with respect to LVEF and left ventricular volumes. SPECT is useful in patients with functional abnormalities, but less reliable in those with normal small cavities. A combined technique is still necessary, and RVEF should be interpreted cautiously.     

Ventricular ejection fraction in patients with dilated cardiomyopathy calculated by gated blood pool SPET processing software: correlation with multigated acquisition and first pass radionuclide ventriculography

This study was performed to find out the left ventricular ejection fraction (LVEF) and right ventricular ejection fraction (RVEF) in patients with dilated cardiomyopathy (DCM) by using commercially available automated gated blood pool scintigraphy (GBPS) processing software and to correlate it with first pass radionuclide ventriculography (FPRNV) and planar multigated acquisition (MUGA). However, till date, no literature exists studying the application of GBPS and planar radionuclide ventriculography techniques in the setting of patients with DCM as a single cohort. Forty-one patients having DCM were prospectively included in the study. First pass RNV and MUGA were performed at rest after in-vivo labeling of red blood cells in all patients. Immediately after obtaining the planar views, GBPS was performed and LVEF and RVEF were calculated. Our results showed that the %LVEF values (mean±SD) calculated by MUGA, GBPS and echo cardiography were 31±11, 34±12 and 32±11, respectively. The % RVEF values (mean±SD) calculated by FPRNV and GBPS were 46±14 and 43±17, respectively. The LVEF values calculated by MUGA, GBPS and echcardiography showed very good correlation r=0.924 and r=0.844, respectively and for both P <0.0001. Bland-Altman plot showed overestimation for LVEF (and a tendency for overestimation of RVEF) values calculated by GBPS compared to MUGA. Values of RVEF calculated by GBPS and FPRNV also showed good correlation (r=0.88; P< 0.0001). In conclusion, the automated GBPS for LVEF and RVEF calculation using GBPS SPET can be routinely applied in DCM patients. Given the practical difficulties with FPRNV like good bolus administration, quantitative blood pool SPET (QBPS) can be used to calculate RVEF. Similarly MUGA and GBPS can be used to calculate LVEF.     

Sixteen-slice spiral CT versus MR imaging for the assessment of left ventricular function in acute myocardial infarction

The aim of this study was to assess global left ventricular (LV) function and regional wall motion using retrospectively ECG-gated 16-slice computed tomography (CT) in comparison with magnetic resonance imaging (MRI). Twenty-one patients (18 male, 65.5±8.6 years) with acute myocardial infarction underwent multislice spiral CT (MSCT) and MRI. From manually drawn endo- and epicardial contours, LV volumes including myocardial mass, peak filling rate (PFR), peak ejection rate (PER), time to PER (TPER) and time from end-systole to PFR (TPFR) were calculated. Regional wall motion was assessed from cine loops using a 16-segment model of the left ventricle. LV function was analyzed using the Bland–Altman method, Pearsons correlation coefficient, multivariate analysis and post hoc t tests. Regional wall motion was evaluated with weighted kappa-statistics. Multivariate analysis revealed significant differences for global LV function as determined by MSCT and MRI. Post hoc t-tests showed significant differences for end-diastolic volume (EDV), PFR and TPER (P<0.05), while there was a good agreement for the LV volumes with an ejection fraction of 46.9±8.4% for MSCT and 46.9±8.9% for MRI. PER, PFR, TPER and TPFR presented a poor correlation and a wide range of scattering between MSCT and MRI. Regional wall motion scores showed a good agreement with =0.791. Sixteen-slice spiral CT allows for reliable assessment of LV volumes, but is not yet suited for the evaluation of all functional parameters. Assessment of regional wall motion at rest is feasible.     

碲锌镉SPECT平衡法门控心血池断层显像重建平面及快速显像方案的研究

目的 通过对比分析传统NaI-SPECT平衡法门控心血池平面显像（简称NaI-SPECT平面显像）与心脏专用碲锌镉（CZT）SPECT（CZT-SPECT）平衡法门控心血池断层显像（简称CZT-SPECT断层显像）及其重建平面显像（简称CZT-SPECT断层重建平面显像）所获得的左、右心室功能参数的相关性及其差异,进行CZT-SPECT断层显像的方法学研究并探讨其优势。 方法 回顾性分析2021年8月至2022年11月在泰达国际心血管病医院行放射性核素平衡法门控心血池显像的患者58例[其中,男性38例、女性20例,年龄（60.6±12.3）岁],所有患者均于同日先后行NaI-SPECT平面显像和CZT-SPECT断层显像,重建CZT-SPECT断层显像数据成平面显像数据,比较和分析NaI-SPECT平面显像（P）、CZT-SPECT断层显像（T）及其重建平面显像（re）获得的左心室射血分数（LVEF）和右心室射血分数（RVEF）。重建3、4和5 min的CZT-SPECT断层显像采集数据,将获得的LVEF（3 min）、LVEF（4 min）、LVEF（5 min）和RVEF（3 min）、RVEF（4 min）、RVEF（5 min）与原始采集数据LVEF（10 min）、RVEF（10 min）进行比较。将LVEF（10 min）和RVEF（10 min）按≥20%、≥30%、≥40%和≥50%重新分为各亚组,并与上述重建数据分别进行分析。计量资料的比较采用配对t检验（或Wilcoxon符号秩检验）,相关性采用Pearson（或Spearman）相关性分析。 结果 LVEF（re）[30.50%（20.00%,38.50%）]、LVEF（P）[31.00%（22.00%,41.00%）]与LVEF（T）[27.00%（19.75%,38.50%）]之间的差异均有统计学意义（Z=−2.645、−3.065,均P<0.05）,LVEF（re）与LVEF（P）之间的差异无统计学意义（Z=−1.057,P>0.05）;RVEF（P）（39.78%±12.16%）、RVEF（T）（41.57%±15.18%）和RVEF（re）（40.88%±13.19%）之间两两比较,差异均无统计学意义（t=−1.949、−1.721、0.883,均P>0.05）;3种显像方法获得的LVEF、RVEF比较,两两之间的相关性均为优秀（r=0.892~0.946,均P<0.001）;LVEF（3 min）、LVEF（4 min）、LVEF（5 min）和RVEF（3 min）、RVEF（4 min）、RVEF（5 min）分别与LVEF（10 min）和RVEF（10 min）比较,差异均有统计学意义（Z=−2.798、−3.288、−3.995,t=−2.187、−3.976、−5.154,均P<0.05）,且相关性均为优秀（r=0.903~0.970,均P<0.001）。亚组分析结果显示,除LVEF≥20%亚组外,其余各亚组中,LVEF（5 min）与LVEF（10 min）、RVEF（5 min）与RVEF（10 min）之间的差异均无统计学意义（Z=−1.853~−1.158,t=−1.804、−0.132,均P>0.05）。 结论 CZT-SPECT断层显像可通过重建获得平面显像数据,结合采集性能优势,可在获得可靠的数据用于后期处理和获得准确的测量结果的同时,进一步降低检查中的辐射剂量或缩短时间。     

Evaluation of left and right ventricular functional parameters with automatic edge detection program of ECG gated blood SPET

An analysis program for ECG gated, blood pool, single photon emission tomography (SPET GBP) is available. This program permits the automatic evaluation of left and right ventricular function, but its reliability has not been thoroughly assessed. The objective of this investigation was to examine the reliability of the parameters derived from SPET GBP. Fifty-three patients who had undergone both SPET GBP and planar, ECG gated, blood pool scintigraphy (planar GBP) were enrolled in the study. Planar GBP was performed with a single-headed gamma camera. From a left anterior oblique projection, data were acquired at 24 frames/cardiac cycle with ECG gating during the equilibrium state. SPET GBP was carried out utilizing a triple-headed gamma camera, with 60 projection views over 360 degrees, with 60 s per view, in 16 frames/cardiac cycle. Left ventricular ejection fraction (LVEF) and right ventricular ejection fraction (RVEF) were calculated by using the analysis program. The reproducibility of these values and the correlation between SPET and planar GBP were assessed. To evaluate the effect of cut-off frequencies of a Butterworth filter, six different cut-off frequencies (order=8, 0.3-1.0 Nyquist) were tested with data obtained from 12 patients. The reproducibility of LVEF by SPET GBP was satisfactory (intra-observer, r=0.95; inter-observer, r=0.96), whereas reproducibility of RVEF by SPET GBP was fair (intra-observer, r=0.83; inter-observer, r=0.83). LVEF with SPET GBP was well correlated (y=1.1x+6.62, r=0.85, P<0.01) with LVEF readings of planar GBP. However, LVEF with SPET GBP was overestimated (mean difference of 12) in comparison with that of planar GBP. The RVEF derived from SPET GBP showed poor correlation (y=0.52x+33, r=0.53, P<0.01) with planar GBP. No significant effect of cut-off frequencies of Butterworth filters was evident in the calculation of LVEF and RVEF (P=0.48 and 0.67) with SPET GBP. It is concluded that SPET GBP with QBS is useful for the evaluation of LVEF. However, measurement of the RVEF showed lower reproducibility compared with measurement of the LVEF.     

Thallium-gated SPECT in patients with major myocardial infarction: effect of filtering and zooming in comparison with equilibrium radionuclide imaging and left ventriculography.

The effect of filtering and zooming on 201TI-gated SPECT was evaluated in patients with major myocardial infarction. METHODS: Rest thallium (TI)-gated SPECT was performed with a 90 degrees dual-head camera, 4 h after injection of 185 MBq 201TI in 32 patients (mean age 61 +/- 11 y) with large myocardial infarction (33% +/- 17% defect on bull's eye). End diastolic volume (EDV), end systolic volume (ESV) and left ventricular ejection fraction (LVEF) were calculated using a commercially available semiautomatic validated software. First, images were reconstructed using a 2.5 zoom, a Butterworth filter (order = 5) and six Nyquist cutoff frequencies: 0.13 (B5.13), 0.15 (B5.15), 0.20 (B5.20), 0.25 (B5.25), 0.30 (B5.30) and 0.35 (B5.35). Second, images were reconstructed using a zoom of 1 and a Butterworth filter (order = 5) (cutoff frequency 0.20 [B5.20Z1]) (total = 32 x 7 = 224 reconstructions). LVEF was calculated in all patients using equilibrium radionuclide angiocardiography (ERNA). EDV, ESV and LVEF were measured with contrast left ventriculography (LVG). RESULTS: LVEF was 39% +/- 2% (mean +/- SEM) for ERNA and 40% +/- 13% for LVG (P = 0.51). Gated SPECT with B5.20Z2.5 simultaneously offered a mean LVEF value (39% +/- 2%) similar to ERNA (39% +/- 2%) and LVG (40% +/- 3%), optimal correlations with both ERNA (r = 0.83) and LVG (r = 0.70) and minimal differences with both ERNA (-0.9% +/- 7.5% [mean +/- SD]) and LVG (1.1% +/- 10.5%). As a function of filter and zoom choice, correlation coefficients between ERNA or LVG LVEF, and gated SPECT ranged from 0.26 to 0.88; and correlation coefficients between LVG and gated SPECT volumes ranged from 0.87 to 0.94. There was a significant effect of filtering and zooming on EDV, ESV and LVEF (P < 0.0001). Low cutoff frequency (B5.13) overestimated LVEF (P < 0.0001 versus ERNA and LVG). Gated SPECT with 2.5 zoom and high cutoff frequencies (B5.15, B5.20, B5.25, B5.30 and B5.35) overestimated EDV and ESV (P < 0.04) compared with LVG. This volume overestimation with TI-gated SPECT in patients with large myocardial infarction was correlated to the infarct size. A zoom of 1 underestimated EDV, ESV and LVEF compared with a 2.5 zoom (P < 0.02). CONCLUSION: Accurate LVEF measurement is possible with TI-gated SPECT in patients with major myocardial infarction. However, filtering and zooming greatly influence EDV, ESV and LVEF measurements, and TI-gated SPECT overestimates left ventricular volumes, particularly when the infarct size increases.     

Left ventricular ejection fraction and volumes from gated single photon emission tomographic myocardial perfusion images: Comparison between two algorithms working in three-dimensional space

Objective. Two different algorithms operating in three-dimensional space, one dependent on surface detection developed at Cedars-Sinai Medical Center (CS) and another dependent on statistical parameters and developed at Stanford University Medical School (SU), were compared in the same patients to assess the left ventricular volumes and the left ventricular ejection fractions (LVEFs) from gated single-photon emission tomography (SPECT) myocardial perfusion images.Methods. Perfusion SPECT images gated in eight time bins were recorded in 40 patients with coronary artery disease 60 minutes after the injection of 925 MBq^99mTc-labeled tetrofosmin at rest. The LVEF values were validated against planar gated ^99mTc-labeled blood pool studies (ERNA).Results. The software success rates were 95% (38/40 patients) for CS and 100% for SU. Agreement between LVEFs measured with CS and SU and agreement between both methods and ERNA were excellent (LVEF_CS = 0.89LVEF_SU + 6.21, r = 0.93; LVEF_SU = 0.92LVEF_ERNA + 0.99, r = 0.94; and LVEF_CS = 0.88LVEF_ERNA + 4.58, r = 0.93). Bland-Altman plots showed that differences between LVEFs from SU and CS and from ERNA were similar across a wide range (20% to 80%) of LVEF values. No relationship between these differences and the severity of perfusion defects was observed. For left ventricular volumes, linear regression analysis showed an excellent correlation between both methods (end-diastolic volume R = 0.97 end-systolic volume R = 0.98), but systematically higher values were obtained with SU (p = 0.013).Conclusion. Measurements of LVEF obtained with CS and SU correspond well with those from the standard, ERNA, even in patients with severe perfusion defects. A close relationship is observed between SU and CS when left ventricular volumes are considered. Measurements of LVEF (and left ventricular volumes) should be considered as an integral part of myocardial perfusion studies whenever possible.     

Left ventricular function and visual phase analysis with equilibrium radionuclide angiography in patients with biventricular device

Purpose Cardiac resynchronisation therapy (CRT) is a technique indicated in patients with moderate to severe heart failure and ventricular dyssynchrony. To evaluate left ventricular ejection fraction (LVEF) and synchronisation changes after CRT with a biventricular pacing implant, we used an equilibrium radionuclide angiography (ERNA). Methods Fifty patients were studied. An ERNA was made 72 h and 6 months after the implant. Two acquisitions were performed: with the CRT device connected and after disconnecting it. In the follow-up, responders were defined as those who had improved in accordance with various clinical variables. Quantitative changes in LVEF and visual changes in synchronisation (phase analysis) were studied comparing the two studies and also comparing the connected and disconnected modes. Results At 6 months, 30 patients were defined as responders. LVEF increased significantly at 6 months compared with the 72-h study only in responders. At 72 h, the number of patients showing a decrease in LVEF (p < 0.05) or a synchronisation worsening after disconnecting the device was higher in responders than in nonresponders. At 6 months, 57% of responders had no synchronisation changes between the connected and disconnected modes, suggesting a resynchronisation process. Conclusions ERNA permits the study of resynchronisation patients, showing a statistical LVEF improvement at 6 months. Moreover, visual phase analysis permits the study of the mechanism involved in the response, with an important number of responders with no changes between the two modes at 6 months. In the 72-h study, after disconnection of the device, LVEF and resynchronisation worsening can predict patient improvement at 6 months.     

Assessment of biventricular function using gated blood pool SPECT with QBS software: comparison with planar radionuclide ventriculography

Quantitative blood pool SPECT (QBS) is a new application for the quantitative assessment of biventricular function from gated blood pool SPECT (TMUGA). In this study, we compared biventricular function between planar radionuclide ventriculography and TMUGA. The reproducibility of measuring biventricular ejection fraction with QBS was also evaluated. MATERIALS AND METHODS: Thirty-five patients with cardiac disease were enrolled. Following intravenous bolus injection of 740 MBq of 99mTc human serum albumin-DTPA, first-pass radionuclide angiography (FP) and 25-gated interval planar multi-gated blood pool scintigraphy (PMUGA) were performed for the measurement of right ventricular ejection fraction (RVEF; %) and left ventricular ejection fraction (LVEF; %), respectively. Subsequently TMUGA data set was acquired with a dual-head gamma camera (16 gated intervals). Then, alternative LVEF and RVEF were measured using TMUGA with QBS. Regional left ventricular wall motion for both PMUGA and TMUGA were assessed with a 4-point scoring system respectively. RESULTS: Automatic biventricular border detection using QBS was feasible in 27 of 35 patients (70.7%). Measurements of TMUGA LVEF and RVEF were well reproducible, with interobserver correlation coefficient of 0.98 and 0.97, respectively. TMUGA LVEF showed excellent correlation with PMUGA LVEF (r = 0.98, SEE = 3.92%). The agreement of LV wall motion score between TMUGA and PMUGA was 88.1% (214 of 243 segments), with a kappa value of 0.82. On the other hand, RVEF determined by QBS had a 12.4% average overestimate compared to the same value obtained by FP. Moreover 95% confidential interval of TMUGA RVEF (-28.8 to +4.0%) was wider than that of TMUGA LVEF (-10.7 to +10.7%). CONCLUSION: TMUGA with QBS analysis provided accurate and reproducible data for global and regional left ventricular function. However, the results of RVEF with TMUGA were not satisfying as a replacement for those with FP and modifying the algorithm were needed to improve accuracy of quantification.     

Assessment of left ventricular function by 201Tl SPECT using left ventricular cavity-to-myocardium count ratio

Equilibrium radionuclide angiography (ERNA) is the 'gold standard' for assessing left ventricular ejection fraction (LVEF). The aim of the study was to determine whether the left ventricular cavity-to-myocardium count ratio (LVCMR) from 201Tl myocardial single photon emission computed tomography (SPECT) correlated with LVEF assessed by ERNA. The study group included 159 consecutive patients (117 male, 42 female), aged 59+/-12 years, who underwent both 201Tl SPECT and ERNA at rest on the same day. The LVCMR was calculated from a mid-ventricular short axis slice on redistribution studies, using two regions of interest (ROIs). One ROI was placed in the centre of the left ventricular cavity (C) and the other was placed in the myocardium with maximum uptake (Mmax): LVCMR= (C/Mmax) x 100. The correlation between LVCMR and LVEF was r = 0.85 (y = 0.943x+5.002; P < 0.0001). The mean calculated values +/- 1 SD were LVCMR=54+/-16% and LVEF=52+/-15%. In conclusion, LVCMR from 201Tl SPECT studies was closely correlated with LVEF from ERNA studies and can be used to easily and rapidly estimate left ventricular function.     

201Tl gated single photon emission computed tomographic myocardial perfusion imaging in the assessment of global and regional left ventricular function. Would it be favoured over equilibrium radionuclide angiography?

BACKGROUND: This study investigates the clinical performance of routine 201Tl gated single photon emission computed tomographic (201Tl GSPECT) myocardial perfusion imaging. Equilibrium radionuclide angiography (ERNA) was used as the standard for comparison. METHODS AND RESULTS: One hundred and seventy-two consecutive patients were submitted to both myocardial 201Tl GSPECT imaging, at stress and in redistribution, and ERNA. Left ventricular ejection fractions (LVEF) and regional wall motion were assessed from both stress and redistribution 201Tl GSPECT datasets, and from ERNA. Linear regression analysis showed a good correlation between LVEF calculated by ERNA and 201Tl GSPECT (r=0.73 at stress, r=0.75 in redistribution, P<0.0001). However, the 95% prediction intervals of 201Tl GSPECT LVEF from ERNA LVEF were wide (minimum 35.4% at stress and 33.2% in redistribution). Moreover, a difference in LVEF > or =10% between ERNA and 201Tl GSPECT was found in 26.4% of cases at stress and 28.6% of cases in redistribution. A fair agreement between ERNA and 201Tl GSPECT was found in regional wall motion assessment in segments with normal or mildly reduced tracer uptake (kappa=0.32 at stress and kappa=0.33 in redistribution). In segments with moderately to severely reduced tracer uptake, a moderate agreement was found in regional wall motion assessment between ERNA and 201Tl GSPECT (kappa=0.44 at stress and kappa=0.42 in redistribution). CONCLUSIONS: Left ventricular function may be misinterpreted in a significant proportion of patients if the calculation of LVEF is based on 201Tl GSPECT. Moreover, the evaluation of regional wall motion by 201Tl GSPECT appears unsatisfactory.     

Integrated cardio-thoracic imaging with ECG-Gated 64-slice multidetector-row CT: initial findings in 133 patients

The purpose of this study was to investigate the possibility of assessing the underlying respiratory disease as well as cardiac function during ECG-gated CT angiography of the chest with 64-slice multidetector-row CT (MDCT). One hundred thirty-three consecutive patients in sinus rhythm with known or suspected ventricular dysfunction underwent an ECG-gated CT angiographic examination of the chest without β-blockers using the following parameters: (1) collimation: 32×0.6 mm with z-flying focal spot for the acquisition of 64 overlapping 0.6-mm slices (Sensation 64; Siemens); rotation time: 0.33 s; pitch: 0.3; 120 kV; 200 mAs; ECG-controlled dose modulation (ECG-pulsing) and (2) 120 ml of a 35% contrast agent. Data were reconstructed: (1) to evaluate the underlying respiratory disease (1-mm thick lung and mediastinal scans reconstructed at 55% of the R-R interval; i.e., “morphologic scans”) and (2) to determine right (RVEF) and left (LVEF) ventricular ejection fractions (short-axis systolic and diastolic images; Argus software; i.e., “functional scans”). The mean heart rate was 73 bpm (range: 42–120) and the mean scan time was 18.11±2.67 s (range: 10–27). A total of 123 examinations (92%) had both lung and mediastinal images rated as diagnostic scans, whereas 10 examinations (8%) had non-diagnostic images altered by the presence of respiratory-motion artifacts (n=4) or cyclic artifacts related to the use of a pitch value of 0.3 in patients with a very low heart rate during data acquisition (n=6). Assessment of right and left ventricular function was achievable in 124 patients (93%, 95% CI: 88–97%). For these 124 examinations, the mean RVEF was 46.10% (±9.5; range: 20–72) and the mean LVEF was 58.23% (±10.88; range: 20–83). In the remaining nine patients, an imprecise segmentation of the right and left ventricular cavities was considered as a limiting factor for precise calculation of end-systolic and end-diastolic ventricular volumes. The mean (±SD) DLP value of the examinations was 279.86 (±117.50) mGy.cm. Assessment of underlying respiratory disease and cardiac function from the same data set was achievable in 92% of the patients with ECG-gated 64-slice MDCT.     

Accuracy of multi-slice computed tomography for measurement of left ventricular ejection fraction compared with cardiac magnetic resonance imaging and two-dimensional transthoracic echocardiography: a systematic review and meta-analysis

Background

Multi-slice computed tomography (MSCT) allows non-invasive assessment of the coronary arteries and simultaneously can provide measurement of left ventricular ejection fraction (LVEF). The accuracy of newer MSCT generations (64-slice or more) for assessment of LVEF compared with magnetic resonance imaging (MRI) and two-dimensional transthoracic echocardiography (TTE) has not been evaluated in a meta-analysis.

Purpose

To evaluate, via a systematic literature review and meta-analysis, whether MSCT can assess LVEF with high accuracy compared with MRI and TTE.

Methods

Electronic databases and reference lists for relevant published studies were searched. Twenty-seven eligible studies provided mean LVEF% with its standard deviation (SD) measured by MSCT versus MRI and TTE. Meta-analysis of weighted mean difference (WMD) and Bland–Altman method were used to quantify the mean difference and agreement between MSCT compared with MRI and TTE.

Results

The results of combining 12 studies showed no significant difference in LVEF% between MSCT and MRI with a WMD of −0.11 (−1.48, 1.26, 95% CI), p = 0.88. Bland–Altman analysis showed excellent agreement between MSCT and MRI with a bias of 0.0 (−3.7, 3.7 ± 1.96SD) with 95% CI. The results of combining 15 studies showed no significant difference in LVEF between MSCT versus TTE measurements with a WMD of 0.19 (−1.13 to 1.50; 95% CI), p = 0.87. Bland–Altman analysis showed excellent agreement between MSCT and TTE with a bias of 0.3 (−4.7, 5.7 ± 1.96SD) with 95% CI.

Conclusion

The newer MSCT generations can provide accurate LVEF measurement compared to MRI and TTE. MSCT represents a valid technique for the combined evaluation of LVEF and coronary artery disease.     

Functional assessment of the right ventricle with gated myocardial perfusion SPECT

BACKGROUND: The evaluation of right ventricular function can provide valuable information in a variety of cardiac and noncardiac conditions. Functional assessment of the right ventricle is difficult because of its anatomy and geometry. The authors describe a method for assessing right ventricular function using gated myocardial perfusion SPECT. METHODS: In 20 patients, right and left ventricular ejection fractions (RVEF, LVEF) were determined using gated blood-pool scintigraphy (GBPS) and gated myocardial perfusion SPECT (GSPECT). To avoid contamination with right atrial activity, the two-frame method was adopted for gated blood-pool data when RVEF was measured. In nine patients with normal right ventricles, an index of wall thickening for the right ventricle was derived from the peak systolic and diastolic counts in the free wall. RESULTS: Linear correlation between the two methods adopted for calculation of LVEF and RVEF was good. Bland-Altman analysis revealed good agreement between the two methods with no specific bias. The mean LVEF was 47.9 +/- 12% (GBPS) and 47.3 +/- 12.4 (GSPECT). The mean RVEF was 43.2 +/- 9.6% (GBPS) and 44.2 +/- 8.5% (GSPECT). In both cases, the values were not significantly different. The mean wall motion index was 35%. There was no correlation between the wall thickness index and ejection fraction, but the index was greater in patients with a normal right ventricle compared with those with reduced RVEF. CONCLUSIONS: Gated SPECT offers an alternative to GBPS for the functional assessment of the right ventricle. Using GSPECT will allow the simultaneous assessment of both the right and left ventricles.     

Gated first pass radionuclide ventriculography. Methods, validation, and applications

Electrocardiographic gating provides an alternative method of acquiring first pass radionuclide ventriculograms from both ventricles. This report details the methods of acquisition and analysis, provides validation and reproducibility data, and describes applications of gated first pass radionuclide ventriculography using a count-based method. Left ventricular ejection fractions measured by gated first pass were correlated quite closely with gated blood pool ventriculography (n = 43; r = 0.95) but less well with contrast angiography (n = 23; r = 0.72). The right ventricular ejection fractions measured by gated first pass compared favorably with gated blood pool ventriculography (n = 32; r = 0.93). When one observer processed the images two times, the reproducibilities of RVEF (n = 10; r = 0.99) and LVEF (n = 10; r = 0.88) were excellent. Similarly, when two observers processed the images independently, the reproducibilities of RVEF (n = 11; r = 0.99) and LVEF (n = 11; r = 0.98) were excellent. The first pass studies were obtained in a right anterior obliquity, which provided the best atrioventricular chamber separation and provided a different view of global ventricular function and segmental wall motion from that provided by the standard blood pool views.     

Accuracy of the automated assessment of left ventricular function with gated perfusion SPECT in the presence of perfusion defects and left ventricular dysfunction: Correlation with equilibrium radionuclide ventriculography and echocardiography

BACKGROUND: Gated single photon emission computed tomography (SPECT) with automated methods allows the quantitative assessment of left ventricular function and perfusion; however, its accuracy must be defined for patients with large earlier infarctions and severe rest perfusion defects, in whom the estimation of endocardial and epicardial borders might be more difficult, even with automated edge-detection techniques. METHODS AND RESULTS: We prospectively compared the automated measurements of left ventricular ejection fraction (LVEF) and volumes from rest-injected gated Technetium 99m (Tc99m) perfusion SPECT with equilibrium radionuclide angiocardiography (ERNA) in 62 patients and the assessment of regional function with echocardiography in 22 patients. Forty-six patients had an earlier myocardial infarction (mean defect size, 34% of left ventricle; SD, 12.7%; range, 8% to 56%); 27 patients had large defects (> or = 20% of left ventricle; LVEF range, 8% to 75%). LVEF, as determined with Cedars-Sinai software (quantitative gated SPECT), correlated well with ERNA (r = 0.941; y = 1.003x + 1.15; P<.0001; SE of the estimate = 6.3%; mean difference -1.3% for LVEF) in the entire study population and in the subgroups of patients with an earlier infarction, severe defects, and large infarctions (> or = 20% of the left ventricle). A correlation existed between gated SPECT and ERNA volumes (r = 0.882, y = 1.040x - 14.7, P<.0001 for end-diastolic volume; r = 0.954, y = 1.147x - 13.9, P<.0001 for end-systolic volumes with the count-ratio technique), but with wider limits of agreement. The exact segmental score agreement between gated SPECT and echocardiography for regional function was 79.8% (281 of 352, kappa = 0.682). CONCLUSIONS: Automated gated SPECT provides an accurate assessment of ejection fraction and regional function, even in the presence of an earlier myocardial infarction with large perfusion defects and significant left ventricular dysfunction.