Doxorubicin cardiotoxicity: Prevention of congestive heart failure with serial cardiac function monitoring with equilibrium radionuclide angiocardiography in the current era

BACKGROUND: Congestive heart failure (CHF) is among the most serious toxicities of doxorubicin, a potent cancer chemotherapeutic agent. Serial left ventricular ejection fraction (LVEF) monitoring during doxorubicin therapy for preventing CHF was proposed over 20 years ago. The current utility and cost-effectiveness of this approach in the present era are not known. METHODS AND RESULTS: Clinical and follow-up data of 265 patients with cancer (age, 53 +/- 14 years; 76% women) undergoing doxorubicin chemotherapy with serial equilibrium radionuclide angiocardiography (ERNA) monitoring (> or =2 studies) were analyzed retrospectively. Patients with a normal baseline LVEF (> or =50%) and a 10% or greater point fall in LVEF to a final value of less than 50% during doxorubicin therapy were considered "at risk" for CHF (n = 41). Over 679 +/- 426 days of follow-up, 7 patients (2.6%) had CHF develop and 90 (34%) died (all cancer-related deaths, with none due to CHF). A comparison of "at-risk" (n = 41 [15%]) and "low-risk" (n = 224 [85%]) groups showed a higher incidence of CHF (12% vs 0.9%, P <.0001), lower baseline LVEF (58% +/- 8% vs 64% +/- 8%, P <.0001), lower value for the lowest LVEF (42% +/- 8% vs 57% +/- 7%, P <.0001), and higher rate of cancer-related deaths (59% vs 29%, P =.0003) in the former despite similar cumulative doxorubicin dose (304 +/- 124 mg/m(2) vs 284 +/- 110 mg/m(2), P = not significant). There were no differences in age, gender, cancer type, and co-morbidity. Cost analysis showed the overall cost of ERNA studies to be lower than the 1-year cost of caring for additional cases of CHF that would potentially be prevented by routine LVEF monitoring. CONCLUSIONS: An incipient fall in LVEF detected on serial ERNA during doxorubicin therapy provides an appropriate and cost-effective approach for predicting and preventing impending CHF. Use of this approach was associated with a low incidence of CHF (2.6%) and no CHF-related mortality in this study.     

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 left ventricular ejection fraction with quantitative gated SPECT: Accuracy and correlation with first-pass radionuclide angiography

BACKGROUND: Quantitative gated single photon emission computed tomography (SPECT [QGS]) software is widely used for the assessment of left ventricular ejection fraction (LVEF). Potentially confounding variables that may affect the accuracy of quantitative analysis of LVEF remain undefined. This study evaluated the accuracy of QGS as a means of determining LVEF in a wide range of LVEF values; evaluated the effect of extracardiac activity, count statistics, heart size, and perfusion defects on the accuracy of QGS LVEF; and compared QGS LVEF obtained at rest with that obtained after stress. METHODS AND RESULTS: QGS-derived LVEF was compared with rest first-pass radionuclide angiography (FPRNA) LVEF in 400 electrocardiographic-gated SPECT studies. The overall correlation between QGS and FPRNA LVEF was only fair (r = 0.66, SEE = 11.85%). In 35 of the patient studies (9%) with high extracardiac activity, the automated software failed, and no correlation was obtained. In the remaining 365 patient studies (91%), left ventricular contours were successfully identified. In these studies, correlation was better (r = 0.74, SEE = 9.77%). Agreement was better for images with high counts (r = 0.81, SEE = 8.66%) than for images with low counts (r = 0.61, SEE = 11.17%). Patient studies with abnormal LVEF had better correlation (r = 0.77, SEE = 6.4%) than studies with normal LVEF (r = 0.46, SEE = 10.2%). Agreement between QGS LVEF and FPRNA LVEF was better in hearts with large end diastolic volumes (>104 mL) than in hearts with small volumes. Overall, mean QGS LVEF was lower than mean FPRNA LVEF (54%+/-14% vs. 58%+/-14%, P<.0001). There was no difference between mean rest and stress QGS LVEF in the same patients, even in patients with stress-induced ischemia. CONCLUSIONS: QGS is a valuable method for assessing resting LVEF. However, QGS LVEF is often lower than FPRNA LVEF. Accuracy is affected by high extracardiac activity, low count density, and small size of the left ventricle.     

Effect of acute postinfusion lipemia and free fatty acids on myocardial contractility: Assessment with radionuclide ventriculography

Equilibrium gated radionuclide ventriculography was used to evaluate the effect of intravenous fat-emulsion overload and excess of free fatty acids (FFA) on left ventricular ejection fraction (LVEF) in 20 patients with and without coronary artery disease (CAD). Fifteen of these patients had normal (>50%) baseline LVEF and 5 had low (<50%) baseline LVEF. From 100 to 150 ml of 20% artificial fat emulsion (Liposyn) was infused over 20–25 min. At the end of the infusion, triglyceridemia reached 820±220 mg% and left ventricular ejection fraction decreased from baseline 62±19% (mean±SD) to 58±16% (P<0.05, paired t-test). After completion of Liposyn infusion, 5,000 U of heparin was administered intravenously and monitoring of LVEF was continuod. One and one-half hours following heparin administration, plasma FFA levels reached 3.7+2.0 mmol/l and LVEF rose to 69±19% (P<0.001, paired t-test). Our data indicate that acute intravenous fat overload can suppress and high pathophysiologic levels of FFA can increase LVEF. This effect is more uniform and statistically more reliable in patients with normal LVEF. The study failed to demonstrate any significant difference in the effect of this pharmacologic intervention between patients with and without CAD.     

Prognostic assessment in coronary artery disease: Role of radionuclide angiography

Left ventricular function is one of the most important determinants, if not the most important determinant, of outcome in paients with coronary artery disease. The ability of radionuclide angiography to assess resting and exercise ejection fraction accurately and reproducibly has been shown to be a critical determinant of survival in large-scale studies of survivors of myocardial infarction, as well as patients with chronic stable angina. In addition, several centers have demonstrated that the exercise ejection fraction is an extremely valuable (and perhaps the most valuable) noninvasive parameter in predicting survival among patients with coronary artery disease. The prognostic insights gained from the exercise ejection fraction add incremental predictive information to the coronary anatomic information obtained from coronary arteriography, especially in patients with multivessel disease and those with left ventricular dysfunction at rest.     

Estimation of left ventricular volume and mass by magnetic resonance imaging: Comparison with quantitative biplane angiocardiography

Magnetic resonance imaging (MRI) is well suited for the delineation of cardiac anatomy. In this study an estimation of left ventricular volume and muscle mass by MRI was attempted, using an iron-shielded resistance magnet (Bruker) with 0.23 T. Images were obtained with ECG gating. For image-processing our own software program was used. Slice images were 8 mm thick and spaced 16 mm. Volumes were standardized for a “normal” LV. Muscle mass was calculated directly from the systolic image as the difference between inner and outer ventricular outline. There was a wide range of volumes and mass (100–300 ml, 200–500 g). For comparison and validation conventional biplane left ventriculography was used. Fourteen patients were studied with MRI, but satisfactory studies were obtained in only 7. Correlation of MRI and angiographic volumes was good (r=0.84). For left ventricular mass it was excellent (r=0.94). Ventricular walls and cavities were clearly outlined. Even minor details of anatomy were recognized. Limitations of MR study included a narrow space for the patient within the system and the long duration of data acquisition time. This paper is dedicated to Professor W. Wenz, Director of the Institute of Diagnostic Radiology, University of Freiburg, on the occasion of his 60th birthday.     

多肽受体靶向放射治疗:现状与进展

临床前及临床多中心试验结果已证实应用放射性核素标记的生长抑素类似物进行多肽受体靶向放射治疗(PRRT)的有效性,不同治疗手段联合治疗能进一步提高PRRT的临床疗效,177Lu与90Y标记的生长抑素类似物联合治疗可以获得更好的疗效,其受体在前列腺与乳腺癌等常见肿瘤细胞上表达的蛙皮素和神经肽Y类似物正在研究中。联合放射性核素标记的蛙皮素和神经肽Y类似物进行多受体肿瘤靶向治疗对于乳腺癌及其淋巴结转移灶的诊断与PRRT也很有希望。     

Operator-interactive method for simultaneous measurement of left and right ventricular volumes and ejection fraction by tomographic electrocardiography-gated blood pool radionuclide ventriculography

BACKGROUND: A method that uses single photon emission computed tomography (SPECT) equilibrium radionuclide angiocardiography (ERNA) to measure right ventricular (RV) and left ventricular (LV) volumes (in milliliters) and ejection fraction (EF) is described. METHODS AND RESULTS: We recorded 35 paired SPECT ERNA and electron beam computed tomography (EBCT) cardiac studies in 27 patients; for comparison with EBCT, a method for measurement of RV and LV volumes and EF with SPECT ERNA was developed in 18 paired studies and was validated and assessed for reproducibility in 17. Validation indicated that SPECT ERNA and EBCT were similar for measurement of RV volume (end-systolic and end-diastolic volumes in a combined analysis) and EF (180+/-74 mL vs 182+/-80 mL and 0.44+/-0.11 vs 0.43+/-0.11, respectively) and for measurement of LV volume and EF (88+/-36 mL vs 84+/-43 mL and 0.53+/-0.081 vs 0.59+/-0.07, respectively). The SPECT ERNA method was quite reproducible. CONCLUSIONS: RV and LV volumes and EF can be measured readily via SPECT ERNA.     

Repeatability of treadmill exercise ejection fraction and wall motion using technetium 99m-labeled sestamibi first-pass radionuclide ventriculography

Background  

Peak treadmill exercise radionuclide ventriculography (RVG) with technetium 99m has recently been validated for determination of left ventricular ejection fraction (LVEF). However, the repeatability of this technique for determination of both LVEF and regional wall motion has not been reported.     

Development and validation of a novel technique for murine first-pass radionuclide angiography with a fast multiwire camera and tantalum 178

BACKGROUND: The use of genetically altered mice as a model system to study cardiovascular disease has created a need for accurate and quantitative assessment of murine ventricular function. To address this very challenging problem, we have developed a technique of murine first-pass radionuclide angiography using pinhole imaging and the short-lived isotope tantalum 178 (Ta-178) with a high-speed multiwire proportional camera (MPC). METHODS AND RESULTS. An MPC was fitted with a pinhole lens of 2-mm-diameter aperture positioned 15 cm from the camera face. The short-lived isotope Ta-178 (half-life 9.3 minutes) was generated from the tungsten 178 (W-178) (half-life 21.7 days)/Ta-178 generator and concentrated on site to an injection volume of 15 to 20 microL. Mice were imaged in the supine position with the chest wall 3 mm from the camera pinhole aperture, and images were acquired at 160 frames per second after a rapid bolus injection of Ta-178. In the absence of a true gold standard, the technology was validated with measurements in control mice and mice with surgically ligated left anterior descending arteries (LADs). In addition, the effects of pharmacologic intervention with verapamil and with dobutamine were observed. Finally, peak aortic velocity measurements obtained with this technology were compared with those obtained with echocardiographic Doppler ultrasonography, the only available quantitative comparator. There was a significant decrease in the mean left ventricular ejection fraction (LVEF) between normal mice (62% +/- 4.6% [mean +/- SEM], n = 12) and mice with experimentally induced myocardial infarction produced by surgical LAD ligation (22% +/- 2.0%, n = 41; P <.01). The LVEF decreased from 51% +/- 5.8% to 37% +/- 3.5% in a group of normal mice receiving verapamil (P <.05, n = 8) and increased from 34% +/- 2.2% to 43% +/- 2.3% in a group of LAD-ligated mice receiving dobutamine (P <.01, n = 48). Peak camera sensitivity during first pass was 25,000 cps/mCi injected. Intraobserver and interobserver variability of LVEF was studied, yielding r = 0.9639 and 0.9529 and SE of the estimate 2.6% and 3.1%, respectively. Reproducibility in serial studies was excellent (r = 0.92, SE of the estimate 5.18). CONCLUSIONS: This study demonstrates the development and use of a promising new method that uses the short-lived radioisotope Ta-178 and MPC for noninvasive quantification of murine ventricular function, that produces accurate and highly reproducible results, and that can be applied in multiple serial studies.     

Correlation of functional parameters derived by equilibrium radionuclide angiocardiography and left ventricular size in patients with old myocardial infarction

A total of 131 patients with old (over 6 months) myocardial infarction (MI) and 18 normal subjects underwent equilibrium radionuclide angiocardiography at rest (rERNA). The following rERNA parameters were assessed: left ventricular ejection fraction (LVEF), peak ejection rate (PER), peak filling rate (PFR), regional wall motion and a left ventricular size index. The patients with old MI were divided into four groups (I to IV) according to increasing left ventricular (LV) size, and the behaviour of the numerical parameters (LVEF, PER, PFR) was evaluated in each group. LVEF proved to be the most sensitive numerical parameter of overall LV performance. PFR decreased significantly from group I to group III but not from group III to group IV, suggesting that for extreme degrees of left ventricular enlargement some compensatory mechanism acts to prevent a too large fall in LV compliance. The effects of the site of the previous MI on LV performance were also evaluated. Both LV size and performance were least affected by postero-inferior MI. The LVEF was, however, a better predictor of LV size than the site of the MI.Supported in part by grant no. 71260 by Ministero della Publica Istruzione     

Clinical relevance of radionuclide angiography and antimyosin immunoscintigraphy for risk assessment in epirubicin cardiotoxicity

Background. Cardiotoxicity is the major limiting factor in anthracycline chemotherapy of advanced neoplastic disease. Epirubicin shows a more favorable therapeutic index than does doxorubicin, but it is still cardiotoxic. Limited data regarding epirubicin cardiotoxicity are available, and suggested guidelines for doxorubicin with left ventricular ejection fraction (LVEF) measurement may not be empirically useful for epirubicin therapy. This study evaluates the diagnostic role of antimyosin immunoscintigraphy for early identification of patients at risk for late pump dysfunction from cardiotoxicity induced by high-dose administration of epirubicin up to high cumulative dosages.Methods and Results. Chemotherapy with epirubicin was administered to 36 patients with cancer at a dosing rate of 160 mg/m² as a bolus injection every 21 days to a cumulative dosage of 960 mg/m². Radionuclide angiography (LVEF) and antimyosin immunoscintigraphy with heart-lung ratio (HLR) measurements were performed before chemotherapy, at intermediate cumulative epirubicin dosages, at the end of treatment, and during the follow-up. LVEF decreased significantly at the end of the treatment and after therapy discontinuation. HLR values were significantly increased at intermediate epirubicin dosage levels and continued to increase to the end of the treatment but thereafter remained substantially unmodified for 3 to 6 months after therapy discontinuation. A value of HLR>1.85 at intermediate epirubicin dosage level showed a sensitivity of 95% and a specificity of 57% as a predictor of late LVEF impairment.Conclusions. LVEF appears more useful at high cumulative dosages and during follow-up to monitor late pump dysfunction, whereas HLR may be effective during the early phase of the therapy in determining which patients are at risk for development of late cardiac dysfunction.     

Assessment of left ventricular function by ECG-gated myocardial perfusion scintigraphy with image inversion technique: Comparison with equilibrium radionuclide angiography

BACKGROUND: Inversion of gated myocardial perfusion imaging has been proposed for the evaluation of left ventricular function. This study compared the results of inversion technique of gated left anterior oblique 45 degrees images (G-LAO 45 degrees) with those provided by equilibrium radionuclide angiography in the assessment of global left ventricular function in the same patients with suspected or known coronary artery disease. METHODS AND RESULTS: A total of 107 patients (85 men and 22 women, mean age 59 +/- 9 years) with suspected or documented coronary artery disease were studied. Eighty-seven underwent a 2-day stress/rest technetium-99m sestamibi single photon emission computed tomography with acquisition of G-LAO 45 degrees images on the day of rest, and 20 underwent thallium-201 stress/redistribution single photon emission computed tomography with G-LAO 45 degrees image acquisition immediately after redistribution imaging. An excellent correlation (P < .001) with no significant differences was found between left ventricular ejection fraction values provided by inversion G-LAO 45 degree and radionuclide angiography in 87 patients studied with Tc-99m sestamibi and 20 patients studied with TI-201. The Bland-Altman analysis demonstrated the difference in absolute ejection fraction values obtained by inversion G-LAO 45 degree images and radionuclide angiography as <8%. The inversion G-LAO 45 degrees left ventricular ejection fraction distinguishes the patients with myocardial infarction (ejection fraction = 43% +/- 13%) and without myocardial infarction (ejection fraction = 60% +/- 5%) (P < .001). In patients with left ventricular ejection fraction <40%, inversion G-LAO 45 degree images provide evaluation of left ventricular function comparable with that obtained by RNA. CONCLUSIONS: Semiautomated myocardial perfusion gated inversion technique analyzed with a count-based method is useful in the evaluation of left ventricular function and provides similar results to those of radionuclide angiography.     

Relationship between right ventricular ejection fraction and maximum exercise oxygen consumption: A methodological study in chronic heart failure patients

BACKGROUND: Peak oxygen consumption at maximum exercise (peak VO(2)) predicts survival in chronic heart failure (CHF) patients. Right ventricular ejection fraction (RVEF) at rest has been reported to correlate with peak VO(2). We evaluated the strength and consistency of the association between peak VO(2) and RVEF measured by different radionuclide ventriculography (RNV) techniques in a prospective cohort study. METHODS AND RESULTS: In 58 consecutive CHF patients (mean age, 53 years; 39 patients with dilated cardiomyopathy; 48 men), upright symptom-limited bicycle ergometry was performed. During exercise, ventilatory and gas exchange data were recorded and peak VO(2) was calculated. RVEF was calculated by use of first-pass (FP) RNV with single and dual region of interest (ROI) acquisition and planar multigated acquisition (MUGA). Irrespective of the method used, RVEF showed no relevant correlation with the corresponding peak VO(2) value (r = 0.11 for FP single ROI, r = 0.06 for FP dual ROI, r = 0.16 for MUGA). Peak VO(2) or changes in peak VO(2) after 6 and 12 months of follow-up were not determined by RVEF measurements. CONCLUSION: In CHF patients no association was found between peak VO(2) at maximum exercise and RVEF at rest with different RNV techniques. Changes in exercise capacity are not reliably reflected by changes in RVEF measurements at rest.     

Influence of left ventricular hypertrophy on infarct size and left ventricular ejection fraction in ST-elevation myocardial infarction

Background

Left ventricular hypertrophy (LVH) predisposes to larger infarct size, which may be underestimated by the left ventricular ejection fraction (LVEF) due to supranormal systolic performance often present in patients with LVH. The aim of the study was to compare infarct size and LVEF in patients with ST-segment elevation myocardial infarction (STEMI) and increased left ventricular mass on cardiac magnetic resonance (CMR).

Methods

The study included unselected group of 52 patients (61 ± 11 years, 69% male) with first STEMI who had CMR after median 5 days from the onset of the event. Left ventricular hypertrophy (LVH) was defined as left ventricular mass index exceeding 95th percentile of references values for age and gender. Infarct size was assessed with means of late gadolinium enhancement (LGE).

Results

LVH was found in 16 patients (31%). In comparison to the rest of the group, patients with LVH had higher absolute and relative infarct mass (p = 0.002 and p = 0.02, respectively). LVH was related to higher prevalence of microvascular obstruction and myocardial haemorrhage and higher number of LV segments with transmural necrosis (p = 0.02, p = 0.01 and p = 0.01, respectively). Despite marked difference in the infarct size between both studied subgroups there was no difference in LVEF and mean number of dysfunctional LV segments.

Conclusions

Patients with LVH undergoing STEMI have larger infarct size underestimated by the LV systolic performance in comparison to patients without LVH.     

Gated SPECT assessment of left ventricular function is sensitive to small patient motions and to low rates of triggering errors: A comparison with equilibrium radionuclide angiography

BACKGROUND: Patient displacements and errors in R-wave detection are the main causes of inaccurate acquisition for gated single photon emission computed tomography (SPECT) and equilibrium radionuclide angiography (RNA). This study aimed to compare the influences of both factors between gated SPECT and RNA determinations of left ventricular ejection fraction. METHODS AND RESULTS: On gated SPECT and RNA acquisitions, recorded in 20 patients with coronary artery disease, we simulated the consequences of (1) 3-dimensional patient displacements of low (6.7 mm), moderate (13.4 mm), and high amplitude (20.1 mm) and (2) an erroneous triggering on T waves in 10% to 40% of recorded beats. Absolute values of left ventricular ejection fraction changes from baseline were higher with gated SPECT compared with RNA for patient displacements of low amplitude (5.0% +/- 3.8% vs 1.2% +/- 0.9%, P < .001) or moderate amplitude (10.0% +/- 6.2% vs 3.0% +/- 2.3%, P = .001) but not for patient displacements of high amplitude (12% +/- 9% vs 9% +/- 7%, P = not significant) and inaccurate triggering (for 20% T-wave triggering, 8.9% +/- 3.6% vs 7.9% +/- 3.0%; P = not significant). CONCLUSION: Contrary to RNA, gated SPECT is vulnerable to small patient displacements, and thus, specific efforts might be useful for limiting this potential cause of erroneous results. Both techniques may be affected by low rates of triggering errors, suggesting that small acceptance windows on cycle length should be recommended not only for RNA but also for gated SPECT.     

Variability of left ventricular ejection fraction and volumes with quantitative gated SPECT: influence of algorithm,pixel size and reconstruction parameters in small and normal-sized hearts

Purpose Several software packages are commercially available for quantification of left ventricular ejection fraction (LVEF) and volumes from myocardial gated single-photon emission computed tomography (SPECT), all of which display a high reproducibility. However, their accuracy has been questioned in patients with a small heart. This study aimed to evaluate the performances of different software and the influence of modifications in acquisition or reconstruction parameters on LVEF and volume measurements, depending on the heart size.Methods In 31 patients referred for gated SPECT, 64² and 128² matrix acquisitions were consecutively obtained. After reconstruction by filtered back-projection (Butterworth, 0.4, 0.5 or 0.6 cycles/cm cut-off, order 6), LVEF and volumes were computed with different software [three versions of Quantitative Gated SPECT (QGS), the Emory Cardiac Toolbox (ECT) and the Stanford University (SU-Segami) Medical School algorithm] and processing workstations. Depending upon their end-systolic volume (ESV), patients were classified into two groups: group I (ESV>30 ml, n=14) and group II (ESV<30 ml, n=17). Agreement between the different software packages and the influence of matrix size and sharpness of the filter on LVEF and volumes were evaluated in both groups.Results In group I, the correlation coefficients between the different methods ranged from 0.82 to 0.94 except for SU-Segami (r=0.77), and were slightly lower for volumes than for LVEF. Mean differences between the methods were not significant, except for ECT, with which LVEF values were systematically higher by more than 10%. Changes in matrix size had no significant influence on LVEF or volumes. On the other hand, a sharper filter was associated with significantly larger volume values though this did not usually result in significant changes in LVEF. In group II, many patients had an LVEF in the higher range. The correlation coefficients between the different methods ranged between 0.80 and 0.96 except for SU-Segami (r=0.49), and were slightly worse for volumes than for LVEF values. In contrast to group I, however, inter-method variability was quite large and most mean LVEF differences were significant. LVEF was systematically highest with ECT and lowest with SU-Segami. With QGS, changes in matrix size from 64² to 128² were associated with significantly larger volumes as well as lower LVEF values. Increasing the filter cut-off frequency had the same effect. With SU-Segami, a larger matrix was associated with larger end-diastolic volumes and smaller ESVs, resulting in a highly significant increase in LVEF. Increasing the filter sharpness, on the other hand, had no influence on LVEF though the measured volumes were significantly larger. Conclusion In patients with a normal-sized heart, LVEF and volume estimates computed from different commercially available software packages for quantitative gated SPECT are well correlated. LVEF and volumes are only slightly sensitive to changes in matrix size. Smoothing, by contrast, is associated with significant changes in volumes but usually not in LVEF values. However, owing to the specific characteristics of each algorithm, software should not be interchanged for follow-up in an individual patient. In small hearts, on the other hand, both the used software and the matrix size or smoothing significantly influence the results of quantitative gated SPECT. LVEF values in the higher range are frequently observed with all the studied software except for SU-Segami. A larger matrix or a sharper filter could be suggested to enhance the accuracy of most commercial software, more particularly in patients with a small heart.     

Quantification of global left ventricular function: comparison of multidetector computed tomography and magnetic resonance imaging. a meta-analysis and review of the current literature

Cardiac morbidity and mortality are closely related to cardiac volumes and global left ventricular (LV) function, expressed as left ventricular ejection fraction. Accurate assessment of these parameters is required for the prediction of prognosis in individual patients as well as in entire cohorts. The current standard of reference for left ventricular function is analysis by short-axis magnetic resonance imaging. In recent years, major extensive technological improvements have been achieved in computed tomography. The most marked development has been the introduction of the multidetector CT (MDCT), which has significantly improved temporal and spatial resolutions. In order to assess the current status of MDCT for analysis of LV function, the current available literature on this subject was reviewed. The data presented in this review indicate that the global left ventricular functional parameters measured by contemporary multi-detector row systems combined with adequate reconstruction algorithms and post-processing tools show a narrow diagnostic window and are interchangeable with those obtained by MRI.     

门控心肌灌注断层显像、平衡法心血池显像和心动超声图测定左室射血分数的比较

目的：探讨门控心肌灌注断层显像（GMPT）、平衡法心血池显像（GBPI）与心动超声（UCG）测定左室射血分数（LVEF）的差别。材料和方法：入选冠心病患者10例，非冠心病患者12例，在72h内完成GMPT、GBPI和UCG检查，获得LVEF值。结果：三种方法测得的LVEF存在显著差异，UCG测得的LVEF明显高于GBPI和GMPT（P均小于0．01）。三种方法测得的LVEF有很好的相关性（P均小于0．01）；GMPT—GBPI之间和GBPI—UCG之间的相关性在冠心病组明显低于非冠心病组（r值分别为：0．640对0．912和0．670对0．892）。结论：GMPT、GBPI和UCG三种方法测定的LVEF在数值上存在差异，GBPI在冠心病患者中应用价值高于另外两种方法。