Gated blood pool SPECT for measurement of left ventricular volumes and left ventricular ejection fraction: comparison of 8 and 16 frame gated blood pool SPECT

Gated blood pool SPECT (GBPS) is an alternative to planar radionuclide ventriculography (PRNV) and offers potential advantages. The aim of this study was to compare 8 and 16 frame GBPS for the determination of left ventricular ejection fraction(LVEF) and left ventricular volumes (LV) in subjects underwent two consecutive GBPS. Method: About 66 consecutive patients (30 men, 36 women; mean age 62.3 ± 10.4 years) referred for PRNV for evaluation of preoperative cardiac risk stratification (n=40), prechemotherapy cardiac function evaluation (n=18, breast cancer), and congestive heart failure patients (n=8). All patients underwent PRNV of 16 frame and GBPS with both of 8 and 16 frame. Results: The mean LVEF calculated with PRNV (58.3 ± 16.8), showed statistically lower than 8-GBPS (70.6 ± 17.7), and 16-GBPS (69.9 ± 16.8) (PRNV vs. 8-GBPS, p < 0.01; PRNV vs 16-GBPS, p < 0.01; 8-GBPS vs 16-GBPS, p > 0.05). The correlation of LVEFS between 8-GBPS and 16-GBPS showed a correlation coefficient of 0.9194 (p < 0.01, 95% CI=0.8712–0.9500). The mean left ventricular end-diastolic volumes (EDV) calculated with 8-GBPS (83.2 ± 33.5 ml), and 16-GBPS (88.4 ± 36.8 ml) showed no statistical differences (p > 0.05). The mean left ventricular end-systolic volumes (ESV) calculated with 8-GBPS (28.1 ± 31.4 ml), and 16-GBPS (30.5 ± 33 ml) showed also no statistical differences (p > 0.05). Comparison of EDV from 8 and 16-GBPS yielded a correlation coefficient of 0.7430 (p < 0.01, 95% CI=0.6108-0.8349). The correlation between ESV of 8-GBPS and 16-GBPS showed a correlation coefficient of 0.9522 (p < 0.01, 95% CI=0.9228–0.9705). Conclusion: This study demonstrated that the LVEFs of 8-GBPS correlated well with that of 16-GBPS. The LVEF of PRNV was significantly lower than those of 8 and 16-GBPS. Also, left ventricular EDV and ESV of 8-GBPS correlated well with those of 16-GBPS. Also, further studies, involving large lumber patients, should be performed to validate the usefulness of GBPS for the evaluation of left ventricular diastolic function.     

Evaluation of left ventricular volumes and ejection fraction by automated gated myocardial SPECT versus cardiovascular magnetic resonance

BACKGROUND: Electrocardiogram-gated myocardial single-photon emission computed tomography (SPECT) with (99m)Tc-tetrofosmin allows simultaneous evaluation of myocardial perfusion and function. In this study, left ventricular volumes, ejection fraction (LVEF), and left ventricular wall volume (LVWV) derived from gated SPECT were compared with measurements from cardiovascular magnetic resonance (CMR), performed within a few hours. METHODS: The study population included 55 patients with known or suspected coronary artery disease, including 13 patients with recent acute myocardial infarction. End-diastolic (EDV) and end-systolic (ESV) volumes, LVEF and LVWV were derived automatically from gated SPECT using commercially available software (QGS). In the CMR studies, manually delineated endocardial and epicardial borders on short-axis slices were used to calculate the volumes. RESULTS: Gated SPECT underestimated EDV by 35 +/- 14 ml (mean +/- SD) (P < 0.001), ESV by 10 +/- 13 ml (P < 0.001), and LVEF by 4 +/- 7 percentage points (P < 0.001). There were no systematic difference in EDV, ESV or LVEF between the methods. SPECT underestimated LVWV by 49 +/- 30 ml (P < 0.001), with a trend towards increasing underestimation by SPECT for larger wall volumes. CONCLUSION: These findings show that gated SPECT slightly underestimates EDV, ESV and LVEF compared with CMR. This underestimation is systematic, however, indicating that ventricular volumes derived from gated SPECT are robust enough to guide clinical management. Estimates of LVWV in patients with large wall volumes are less accurate.     

门控心肌显像QGS软件与心血池显像测量 左室射血分数比较

心肌灌注显像及心血池显像是临床常用的核素心脏检查,前者可提供心肌的血流灌注情况,后者可以了解心脏的功能,这两方面信息对于冠心病的诊断、治疗方案的选择及预后评价都具有重要的作用.Germeno等设计了一种三维测量心室容积及射血分数的全自动化软件--定量门电路SPECT软件(QGSPECT),采用该软件即可在一次心肌灌注断层显像采集信息的基础上,同时获得心脏功能参数[1].本研究即应用该软件测定左室射血分数(LVEF),并与平衡法心血池显像测量LVEF进行比较,以评价其临床应用价值.     

Assessment of left ventricular ejection fraction measured by quantitative gated SPECT

Purpose: The purpose of this study was to evaluate the reliability of left ventricular ejection fraction (LVEF) measured by quantitative gated SPECT (QGS). We compared the efficacy of LVEF assessment among Tc-99m tetrofosmin gated SPECT imaging, contrast left ventriculography (LVG), and first-pass radionuclide angiography (FP). Patients: One-hundred and seven patients with ischemic heart disease underwent QGS and LVG simultaneously within 3 months, and 92 of the 107 patients also underwent FP at the same time. Results: QGS progressively overestimated LVEF at the lower range of end-systolic volume (ESV), especially in patients with small hearts. Moreover, the QGS technique systemically tended to underestimate LVEF in comparison with LVG. However, linear regression analysis demonstrated a good correlation between the LVEF values measured by QGS and those measured by both LVG (p<0.0001) and FP (p<0.0001). Conclusion: Although QGS has a tendency to overestimate LVEF in patients with small hearts, and to systemically underestimate LVEF compared with LVG, this technique is still a reliable clinical tool for measurement of LVEF.     

门控心肌显像与心血池显像测量左室射血分数的比较

目的评价ECToolbox软件测量门控心肌显像左室射血分数(LVEF)的临床价值.方法 31例患者接受静息态门控心肌显像,用ECToolbox软件测量LVEF,并与一周内门控心血池显像测量的结果比较.结果全部患者用ECToolbox软件测量值与心血池显像测量值的相关性为r=0.699(P<0.001);二者无统计学差别(P＞0.05).EDV<70 ml组患者ECToolbox软件测量值与心血池显像测量值无相关性;前者高于后者(P<0.05).EDV≥70 ml组ECToolbox软件测量值与心血池显像测量值呈强相关(r=0.834,P<0.001);二者无统计学差别(P＞0.05).ECToolbox软件测量值对左室收缩功能是否正常的判断与门控心血池显像无差别(P＞0.05).结论用门控心肌显像ECToolbox软件测量LVEF与门控心血池显像比较相关性好且结果准确,但EDV<70 ml时会高估测量值.     

Normal limits for left ventricular ejection fraction and volumes determined by gated single photon emission computed tomography--a comparison between two quantification methods

To compare gender-related normal limits for left ventricular (LV) ejection fraction (EF), end-diastolic and end-systolic volumes (EDV and ESV), obtained using two myocardial perfusion-gated single photon emission computed tomography (SPECT) quantification methods. A total of 185 patients were retrospectively selected from a consecutive series of patients examined for coronary artery disease (CAD) or for management of known CAD. Patients were included in the study group if they had normal or probably normal results with stress and rest perfusion imaging and if the combined interpretation of perfusion studies and gated rest studies showed no signs or suspicion of myocardial infarction. The gated SPECT studies were performed using a 2-day stress/gated rest Tc-99m sestamibi protocol. All patient studies were processed using CAFU and quantitative-gated SPECT (QGS), the two software packages for quantification of gated SPECT images. The lower normal limits for EF were higher for CAFU compared with QGS for both women (59% versus 53%) and men (54% versus 47%). The upper normal limits for EDV were also higher for CAFU compared with QGS for both women (133 versus 107 ml) and men (182 versus 161 ml). The differences between the software packages were small for ESV (women 44 versus 44 ml; men 69 versus 74 ml). Gender-specific normal limits need to be applied for LV EF and volumes determined by gated SPECT. Separate criteria for abnormal LV EF and EDV need to be used for women and men depending on the software package used.     

Quantification of left ventricular volumes and ejection fraction from gated 99mTc‐MIBI SPECT: MRI validation of the exini heart software package

The aim of the study was to validate the accuracy of the exini heart software (exini ) package in assessing left ventricular end‐diastolic/systolic volumes (EDV, ESV) and ejection fraction (LVEF) from gated ^99mTc‐MIBI single‐photon emission tomography (SPECT). Cardiac magnetic resonance imaging (cMRI) was used as reference. Furthermore, effects of perfusion defects and image quality in SPECT on correlation between gated SPECT and magnetic resonance imaging were investigated. Methods: Seventy patients were examined using gated SPECT (rest study, eight gates per cardiac cycle). EDV, ESV and LVEF were calculated from gated SPECT using exini . Directly before or after SPECT, cMRI (20 gates cardiac per cycle) was performed. EDV, ESV and LVEF were calculated using Simpson’s rule. Perfusion defects were quantified using the summed‐rest‐score (SRS). Total number of myocardial counts were used to rate image quality. Results: Correlation between results of gated SPECT and cMRI was high for EDV (R = 0·89) and ESV (R = 0·94) and good for LVEF (R = 0·78). ESV (exini 54 ± 31 ml versus cMRI 57 ± 34 ml) and LVEF (exini 62·9 ± 11·7% versus cMRI 60·6 ± 13·9%) did not differ significantly whereas exini overestimated EDV significantly compared with cMRI (exini 144 ± 41 ml versus cMRI 137 ± 36 ml; P<0·005). No correlation was found between absolute differences of the results given by gated SPECT and cMRI and SRS or total myocardial counts (R < 0·18). Conclusion: End‐diastolic volume, ESV and LVEF calculated from gated SPECT using exini agree with cMRI over a wide range of values. Correlation between both the methods was good for EDV and ESV, and acceptable for LVEF. No relevant influence of image quality or SRS on the accuracy of exini results was found.     

Quantification of left ventricular volumes and ejection fraction using freehand transthoracic three-dimensional echocardiography: comparison with magnetic resonance imaging.

OBJECTIVES: Our aim was to validate 3-dimensional echocardiography (3DE) for assessment of left ventricular (LV) end-diastolic volume, end-systolic volume (ESV), stroke volume, and ejection fraction (EF) using the freehand-acquisition method. Furthermore, LV volumes by breath hold-versus free breathing-3DE acquisition were assessed and compared with magnetic resonance imaging (MRI). METHODS: From the apical position, a fan-like 3DE image was acquired during free breathing and another, thereafter, during breath hold. In 27 patients, 28 breath hold- and 24 free breathing-3DE images were acquired. A total of 17 patients underwent both MRI and 3DE. MRI contours were traced along the outer endocardial contour, including trabeculae, and along the inner endocardial contour, excluding trabeculae, from the LV volume. RESULTS: All 28 (100%) breath hold- and 86% of free breathing-3DE acquisitions could be analyzed. Intraobserver variation (percentual bias +/- 2 SD) of end-diastolic volume, ESV, stroke volume, and EF for breath-hold 3DE was, respectively, 0.3 +/- 10.2%, 0.3 +/- 14.6%, 0.1 +/- 18.4%, and -0.1 +/- 5.8%. For free-breathing 3DE, findings were similar. A significantly better interobserver variability, however, was observed for breath-hold 3DE for ESV and EF. Comparison of breath-hold 3DE with MRI inner contour showed for end-diastolic volume, ESV, stroke volume, and EF, a percentual bias (+/- 2 SD) of, respectively, -13.5 +/- 26.9%, -17.7 +/- 47.8%, -10.6 +/- 43.6%, and -1.8 +/- 11.6%. Compared with the MRI outer contour, a significantly greater difference was observed, except for EF. CONCLUSIONS: 3DE using the freehand method is fast and highly reproducible for (serial) LV volume and EF measurement, and, hence, ideally suited for clinical decision making and trials. Breath-hold 3DE is superior to free-breathing 3DE regarding image quality and reproducibility. Compared with MRI, 3DE underestimates LV volumes, but not EF, which is mainly explained by differences in endocardial contour tracing by MRI (outer contour) and 3DE (inner contour) of the trabecularized endocardium. Underestimation is reduced when breath-hold 3DE is compared with inner contour analysis of the MRI dataset.     

门控心肌显像在测定左心室射血分数中的应用

目的:应用单光子发射计算机体层摄影(SPECT)技术同时测定不同采集条件下左心室射血分数(LVEF)值,并与超声LVEF值比较,研究其一致性和相关性。方法:选择172例受试者,利用SPECT共行门控显像技术,用99mTc-MIBI作为示踪剂,同时将心动周期设定8和16等份,在一次采集中得到两种条件的LVEF值,并与1周时间所得超声LVEF值作比较,研究门控心肌显像在LVEF测定中的影响因素,以及与常规超声法有无相关性。结果:统计分析显示,心动周期分成8和16等份所得的LVEF值大小是不同的,后者LVEF值较大,但两种方法所得结果存在相关关系。另一方面,SPECT所得的LVEF值均较超声心动图(UCG)所得值大,但与UCG所得结果具有很好一致性。结论:门控心肌显像在心肌活力判断时,利用共行显像技术可同时得到LVEF等心功能参数,其LVEF大小与超声结果有很大相关性,但其值存在显著差异,其正常参考范围尚需进一步研究。     

Rapid freehand scanning three-dimensional echocardiography: accurate measurement of left ventricular volumes and ejection fraction compared with quantitative gated scintigraphy.

This study was performed to assess clinical feasibility of rapid freehand scanning 3-dimensional echocardiography (3DE) for measuring left ventricular (LV) end-diastolic and -systolic volumes and ejection fraction using quantitative gated myocardial perfusion single photon emission computed tomography as the reference standard. We performed transthoracic 2-dimensional echocardiography and magnetic freehand 3DE using a harmonic imaging system in 15 patients. Data sets (3DE) were collected by slowly tilting the probe (fan-like scanning) in the apical position. The 3DE data were recorded in 10 to 20 seconds, and the analysis was performed within 2 minutes after transferring the raw digital ultrasound data from the scanner. For LV end-diastolic and -systolic volume measurements, there was a high correlation and good agreement (LV end-diastolic volume, r = 0.94, P <.0001, standard error of the estimates = 21.6 mL, bias = 6.7 mL; LV end-systolic volume, r = 0.96, P <.0001, standard error of the estimates = 14.8 mL, bias = 3.9 mL) between gated single photon emission computed tomography and 3DE. There was an overall underestimation of volumes with greater limits of agreement by 2-dimensional echocardiography. For LV ejection fraction, regression and agreement analysis also demonstrated high precision and accuracy (y = 0.82x + 5.1, r = 0.93, P <.001, standard error of the estimates = 7.6%, bias = 4.0%) by 3DE compared with 2-dimensional echocardiography. Rapid 3DE using a magnetic-field system provides precise and accurate measurements of LV volumes and ejection fraction in human beings     

Comparison of gated single-photon emission computed tomography with magnetic resonance imaging for evaluation of left ventricular volumes and ejection fraction in patients with idiopathic dilated cardiomyopathy

To prospectively compare the left ventricular end-diastolic volume (LVEDV), end-systolic volume (LVESV), and ejection fraction (LVEF) obtained from gated perfusion single photon emission computed tomography (GSPECT) with those obtained from cardiac magnetic resonance imaging (MRI) in patients with idiopathic dilated cardiomyopathy (IDC). Twenty-one patients with IDC (6 females) with a median age of 45 years (range 17–65) were scheduled for ^99mTc-tetrofosmin-GSPECT and MRI within a 3 h interval. In both methods LV volumes were analyzed with the Simpson method. Both GSPECT and MRI were successfully completed in 90% of patients. Close linear correlations were observed between the two methods in LVEDV (R = 0.918; P < 0.001) and LVESV (R = 0.946; P < 0.001), but correlations were significantly weaker in LVEF (R = 0.323; P = 0.082). LVEDV and LVESV were smaller in GSPECT than in MRI (161 ± 73 vs. 214 ± 87 ml, P < 0.001, and 116 ± 64 vs. 138 ± 72 ml, P < 0.001, respectively). In 4 patients (21%) the LVEDV index was considered normal by GSPECT and increased by MRI, if MRI-derived normal values were used. No difference was found between GSPECT and MRI when LVEF_MRI was ≤40%, but GSPECT showed smaller LVEF when LVEF_MRI was over 40% (33 ± 11 vs. 50 ± 5%; P < 0.05). The finding of increased LVEDV in GSPECT is reliable compared with MRI. However, LV volumes were underestimated by GSPECT and no direct comparisons can be made between methods in follow up studies. Abnormal results should be confirmed by another imaging modality, such as MRI, if these findings have therapeutic consequences.     

Left ventricular aneurysm in the scope of gated perfusion SPECT: accuracy of detection and ejection fraction calculation

PURPOSE: The objective of this trial was to investigate the capacity of gated perfusion SPECT (GPS) to detect left ventricular aneurysm (ANV) by comparing QGS and 4D-MSPECT (4DM) algorithms with radionuclide ventriculography (RVG). Secondarily, the comparison of GPS ejection fraction (EF) measurements with those of contrast left ventriculography (LVG) and RVG was aimed. METHODS: Twenty-five patients with ANV confirmed by LVG were studied. The patients underwent RVG and rest Tc-99m-tetrofosmin GPS 1 week after LVG. A 9-segment model was used both in RVG and GPS evaluation. Aneurysm was defined by scoring the wall motion (WM) and phase analysis in RVG; perfusion, wall thickening and WM in GPS. RESULTS: The detection rate of ANV was 96%, 84% and 52% for RVG, QGS and 4DM, respectively. The LVG mean EF (43.52% +/- 16.93%) was significantly higher (P < 0.01) than those of RVG (29.40% +/- 10.90), QGS (30.04% +/- 13.25%) and 4DM (34.92% +/- 13.01%). Moderate to high EF correlation values were obtained between LVG and GPS (r = 0.71-0.79) and GPS-RVG (r = 0.69). There was no significant EF difference between the radionuclide methods except between 4DM-EF and RVG-EF (5.52%, P < 0.05). Wide Bland-Altman limits were observed between the radionuclide methods in EF comparisons (range: 30.5-38.5%). CONCLUSION: GPS seems to have a role in the non-invasive investigation of ANV. QGS-GPS proved to be more reliable (84%) than 4DM-GPS (52%) in the ANV detection. The localization and the extent of the aneurysm itself as well as perfusion and function of adjacent segments may affect aneurysm diagnosis by means of GPS. RVG, QGS-GPS and 4DM-GPS seem not to be interchangeable for routine EF calculation in ANV patients.     

Clinical relevance of left ventricular volumes and function assessed by gated SPECT in paediatric patients

Left ventricular (LV) end-diastolic and end-systolic volumes (EDV, ESV) and ejection fraction (EF) can be measured by echocardiography and gated single photon emission computed tomography (G-SPECT). The literature is rich in works on G-SPECT in adults, but lacks data for children. This work evaluates the accuracy of G-SPECT in children, compared to echocardiography. PATIENTS AND METHODS: The study comprised 60 children. Eighteen with history of sickle cell disease, 5 dilated cardiomyopathy, 12 valvular heart disease and one with hyperlipidaemia. Other 24 children free from cardiac problems were included. All patients were given 185-370 MBq (5-10 mCi) of 99mTc-MIBI or 99mTc-Myoview. Resting G-SPECT was acquired 45-60 min after injection. LV volumes and EF were measured by G-SPECT and echocardiography. RESULTS: In all 60 cases, the correlation coefficients between both methods were 0.66 for EDV, 0.73 for ESV and 0.42 for EF. The 36 diseased children yielded fair to weak correlations for EDV, ESV and EF (r = 0.69, 0.74 and 0.41 respectively). The EDV was larger by echocardiography than G-SPECT (81.95 +/- 28.87 vs. 65.91 +/- 31.59 ml, p < 0.01). The ESV was also larger by echocardiography (39.13 +/- 15.96 vs. 23.44 +/- 18.04 ml, p < 0.01). The EF by G-SPECT (67.32 +/- 11.63%) was higher than by echocardiography (52.65 +/- 11.77%), (p < 0.01). The 24 normal subjects yielded almost the same level of weak correlation between both methods for EDV, ESV and EF (r = 0.59, 0.69, and 0.44 respectively). CONCLUSION: LV volumes and EF computed by G-SPECT correlated poorly with echocardiography in small ventricles. Consequently, G-SPECT has a limited clinical usefulness in paediatrics.     

Comparison of left ventricular volumes and ejection fraction by monoplane cineventriculography, unenhanced echocardiography and cardiac magnetic resonance imaging

Right-anterior-oblique (RAO) monoplane cineventriculography is usually applied in cardiac catheter labs to assess the left ventricular (LV) function. However, it is uncertain whether this technique is reliable in clinical routine. Unenhanced two-dimensional echocardiography was reported to underestimate left ventricular volumes. The aim of this study was to compare these two conventional techniques with cardiac magnetic resonance imaging (MRI), the present gold standard for the determination of LV function, to evaluate whether the results from the conventional techniques are reliable and in accordance with each other. Seventy-two patients were retrospectively recruited and analysis of the three techniques was performed. Compared with MRI, RAO cineventriculography underestimated LV end-systolic volumes (ESV), and overestimated LV ejection fraction (EF); two-dimensional echocardiography underestimated LV end-diastolic volume (EDV) and EF. Correlation coefficients on EDV, ESV, and EF were 0.8806, 0.9201, and 0.8864 between echocardiography and MRI (P < 0.01, for all), followed by 0.7718, 0.8835, and 0.7785, between cineventriculography and MRI (P < 0.01, for all), and 0.7006, 0.7680, and 0.7644 between cineventriculography and echocardiography (P < 0.01, for all). Echocardiography and MRI showed the highest inter-technique correlation coefficients, and the narrowest Bland-Altman limits of agreement for EDV, ESV and EF. EDV, ESV and EF determined by RAO monoplane cineventriculography, unenhanced two-dimensional echocardiography and MRI were in high accordance with each other, with wide variances between the techniques. Although not interchangeable, RAO monoplane cineventriculography, unenhanced two-dimensional echocardiography, and cardiac MRI are reliable tools in clinical routine for the assessment of LV volumes and function.     

Feasibility and accuracy of left ventricular volumes and ejection fraction determination by fundamental, tissue harmonic, and intravenous contrast imaging in difficult-to-image patients.

The need to enhance the echocardiographic determination of left ventricular ejection fraction is greatest in patients with suboptimal images. Intravenous contrast (CON) and tissue harmonic imaging (THI) are 2 important methods for enhancing endocardial border definition. However, the comparative feasibility and accuracy of THI and contrast-enhanced power harmonic imaging in difficult-to-image patients have not been examined. We assessed the comparative accuracy of THI and CON in determining EF and ventricular volumes in patients with suboptimal fundamental images. We demonstrated that CON is feasible and exhibits a greater correlation with ejection fraction and ventricular volumes determined by radionuclide angiography (standard of comparison) than THI in this difficult-to-image population, with no reported side effects. For both ejection fraction and ventricular volumes, the observer variability was least for CON, intermediate with THI, and greatest for fundamental imaging.     

门控心肌显像评价冠心病左心室舒张末期瞬间缺血扩张的价值

目的:探讨左心室舒张末期瞬间扩张比(TID)与血管狭窄程度和累及范围关系。方法:收集2004年5月至2006年12月在我院行99mTc-MIBI心肌灌注运动和负荷检查的患者183例,按冠状动脉造影结果所示的血管狭窄程度和累及范围及核素灌注显像的缺血程度分类,比较不同程度的狭窄和缺血TID值。结果:在无狭窄组和无缺血组的TID值分布为0.9～1.1,狭窄组和缺血组TID值随累及范围扩大和严重程度加重而增加,但在轻度缺血及狭窄组与正常组的比较中未见明显统计学差异,而狭窄程度大于70%或心肌灌注呈不可逆的缺血组TID值均有显著改变。结论:门控心肌灌注显像的TID计算可反映心功能状况,对评估心肌缺血造成的心功能损害具一定参考意义。     

Single and biplane TrueFISP cardiovascular magnetic resonance for rapid evaluation of left ventricular volumes and ejection fraction.

INTRODUCTION: Cardiovascular magnetic resonance (CMR) allows very accurate, but time-consuming, volume assessment by the short-axis slice summation technique. The single and biplane methods of volume assessment are used less, partly because FLASH cine imaging provides poor blood-myocardium contrast in long-axis views. TrueFISP gives excellent blood-myocardium contrast, even in patients with heart failure. We hypothesized that the single plane and biplane methods of volume assessment in TrueFISP images might provide an acceptable degree of accuracy and be quicker than the short axis method, and that single and biplane left ventricular volume assessment would be more accurate with TrueFISP than with FLASH in patients with impaired ventricular function. METHODS: Short- and long-axis CMR images were obtained by FLASH and TrueFISP with a 1.5-T scanner. We determined the accuracy of both single and biplane long-axis methods for left ventricular volume and ejection fraction (EF) measurements compared with the conventional short-axis method in 10 heart failure patients using both FLASH and TrueFISP and in 9 healthy subjects using TrueFISP. RESULTS: No difference in volumes and EF was found between the single plane method, the biplane method, and the short-axis method using TrueFISP for image acquisition, in both patients and healthy subjects. The same was true of the results obtained by FLASH in the patients with heart failure. CONCLUSIONS: The single and biplane methods, regardless of whether TrueFISP or FLASH is used, are a reasonable and rapid alternative to the conventional short-axis approach for left ventricular volume and EF assessment in patients with heart failure and impaired ventricular function.     

A comparison of visual and quantitative assessment of left ventricular ejection fraction by cardiac magnetic resonance

To determine the accuracy of visual analysis of left ventricular (LV) function in comparison with the accepted quantitative gold standard method, Cardiac Magnetic Resonance (CMR). Cine CMR imaging was performed at 1.5 T on 44 patients with a range of ejection fractions (EF, 5–80%). Clinicians (n = 18) were asked to visually assess EF after sequentially being shown cine images of a four chamber (horizontal long axis; HLA), two chamber (vertical long axis; VLA) and a short axis stack (SAS) and results were compared to a commercially available analysis package. There were strong correlations between visual and quantitative assessment. However, the EF was underestimated in all categories (by 8.4% for HLA, 8.4% for HLA + VLA and 7.9% for HLA + VLA + SAS, P all < 0.01) and particularly underestimated in mild LV impairment (17.4%, P < 0.01), less so for moderate (4.9%) and not for severe impairment (1%). Assessing more than one view of the heart improved visual assessment of LV, EF, however, clinicians underestimated EF by 8.4% on average, with particular inaccuracy in those with mild dysfunction. Given the important clinical information provided by LV assessment, quantitative analysis is recommended for accurate assessment.     

Cardiac resynchronization therapy: effects on left and right ventricular ejection fraction during exercise

In patients with heart failure and wide QRS complex, cardiac resynchronization therapy (CRT) is associated with improvement of symptoms and cardiac function. This study examined the effects of a 3-month period of CRT on left ventricular (LV) and right ventricular (RV) ejection fraction (EF) and on LV volumes, both at rest and during exercise. A CRT system was implanted in 15 patients with severe heart failure and wide QRS. Before implant and 3 months later, all patients underwent assessment of cardiac performance with equilibrium Tc(99) radionuclide angiography with imaging in the best septal left anterior oblique view. Exercise was performed on a bicycle ergometer. At 3 months, a significant improvement in New York Heart Association functional class was observed, and radionuclide angiography showed a significant decrease in LV volumes and a significant increase in LVEF at rest, as well as a significant increase in LVEF during exercise. The remodeling processes associated with CRT did not appear to include RV function, since RVEF did not improve, and changes in RVEF did not correlate with changes in LVEF, neither at rest nor during exercise.