Electrocardiograph-gated single photon emission computed tomography radionuclide angiography presents good interstudy reproducibility for the quantification of global systolic right ventricular function

BACKGROUND: Electrocardiograph-gated single photon emission computed tomography (SPECT) radionuclide angiography provides accurate measurement of right ventricular ejection fraction and end-diastolic and end-systolic volumes. AIM: In this study, we report the interstudy precision and reliability of SPECT radionuclide angiography for the measurement of global systolic right ventricular function using two, three-dimensional volume processing methods (SPECT-QBS, SPECT-35%). These were compared with equilibrium planar radionuclide angiography. METHODS: Ten patients with chronic coronary artery disease having two SPECT and planar radionuclide angiography acquisitions were included. RESULTS: For the right ventricular ejection fraction, end-diastolic volume and end-systolic volume, the interstudy precision and reliability were better with SPECT-35% than with SPECT-QBS. The sample sizes needed to objectify a change in right ventricular volumes or ejection fraction were lower with SPECT-35% than with SPECT-QBS. The interstudy precision and reliability of SPECT-35% and SPECT-QBS for the right ventricle were better than those of equilibrium planar radionuclide angiography, but poorer than those previously reported for the left ventricle with SPECT radionuclide angiography on the same population. CONCLUSION: SPECT-35% and SPECT-QBS present good interstudy precision and reliability for right ventricular function, with the results favouring the use of SPECT-35%. The results are better than those of equilibrium planar radionuclide angiography, but poorer than those previously reported for the left ventricle with SPECT radionuclide angiography. They need to be confirmed in a larger population.     

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.     

Evaluation of regurgitant fraction of the left ventricle by gated cardiac blood-pool scanning using SPECT

Regurgitant fraction (RF) of patients with and without mitral regurgitation (MR) and/or aortic regurgitation (AR) was evaluated by gated cardiac blood-pool scanning using single photon emission computed tomography (SPECT). Using the stroke count image of a short-axis tomogram to separate the right atrium and ventricle, the left ventricular stroke count (LVSC) and right ventricular stroke count (RVSC) were determined. The RF equaled (LVSC - RVSC)/LVSC. Calculated RF in 14 subjects without significant regurgitation by contrast angiography was 5.8 +/- 5.9% (mean +/- s.d.), RF of 17 cases with angiographic regurgitation was 42.5 +/- 16.8% (p less than 0.001). The sensitivity of the radionuclide method compared to angiography was 94% (16/17 cases), and specificity was 100% (14/14 cases). RF of mild Re (1+ or 2+) was 26.0 +/- 8.9% (n = 6) and RF of severe Re (3+ or 4+) was 51.5 +/- 12.7% (n = 11) (p less than 0.001). Correlation between the RF determined with the radionuclide method and with cardiac catheterization was good (y = 5.85 + 0.700 x, r = 0.821, n = 17). We conclude that RF of MR and/or AR can be accurately evaluated by gated cardiac blood-pool scanning using SPECT.     

Assessment of right ventricular afterload in mitral valve diseases with radionuclide angiography

Right ventricular function at rest and during exercise was studied in 33 patients with mitral valve disease by equilibrium gated radionuclide angiography using 99mTc in vivo labeled red blood cells. Radionuclide measurements of right ventricular ejection fraction (RVEF) were correlated with mean pulmonary arterial pressure (mPAP). RVEF decreased significantly with exercise. There was no significant correlation between RVEF at rest and mPAP. However, mPAP showed significant negative correlation with RVEF during exercise and with the changes of RVEF from rest to exercise. It is concluded that RVEF during exercise in mitral valve disease is affected by right ventricular afterload, and the measurements of RVEF at rest and during exercise by equilibrium gated radionuclide angiography is useful to assess right ventricular afterload.     

左室室壁瘤的影像学检查研究

目的：探讨诊断室壁瘤（ＶＡ）最佳方法及早期诊断ＶＡ。材料与方法：对１９９６０１～１９９８０９住院的３７例心肌梗塞（其中急性心梗２８例,陈旧性心梗９例）怀疑ＶＡ患者进行观察,男２９例,女８例,年龄３３～８０岁,平均６０．９±９．２岁,全部病例均做心电图、超声心动图、放射性核素心室显像,其中１０例做左室造影。结果：放射性核素心室显像、超声心动图、心电图对ＶＡ的检出率分别为８３．７％,６４．９％和７８．４％,放射性核素心室显像与左室造影结果一致。放射性核素心室显像发现５例位于下壁的ＶＡ,但超声心动图仅发现１例,心电图无阳性发现。结论：无创性检查对ＶＡ的检出,放射性核素心室显像较超声心动图、心电图更敏感,特别是位于下壁的ＶＡ。     

Scintigraphic imaging of a case of congenitally corrected transposition of the great vessels and an adult case of single atrium and single ventricle

We report on the clinical utility of radionuclide angiography and gated blood pool single emission computed tomography (gated blood pool SPECT) in two patients having congenital heart disease. Both conventional equilibrium radionuclide angiography and gated blood pool SPECT demonstrated the connection of the great vessels with both ventricles in a 15-year-old male patient with a congenitally corrected transposition of the great vessels. In particular, the latter procedure could provide very useful information about the ventricular morphology and inversion which is important for diagnosing this disorder. The second case is an extremely rare 42-year-old female patient with a single atrium and single ventricle. She underwent first-pass and multiple gated blood pool angiography from the anterior, right and left oblique views. The combination of these scintigraphic techniques revealed an insufficiency in anatomical correlations among the single atrium, atrioventricular valve, single ventricle and the great vessels in addition to the connection of superior vena cava with the single atrium, and the atrioventricular valve. Thus, conventional equilibrated angiography from multiple views and gated blood pool SPECT seems to be very reliable not only for anatomical evaluation but also for clinical course observation in patients with complicated congenital heart disease.     

Late Gadolinium Enhancement of Left Ventricular Papillary Muscles in Patients with Mitral Regurgitation

ObjectiveArrhythmogenic mitral valve prolapse (MVP) is an important cause of sudden cardiac death characterized by fibrosis of the papillary muscles or left ventricle (LV) wall, and an association between late gadolinium enhancement (LGE) of the LV papillary muscles and ventricular arrhythmia in MVP has been reported. However, LGE of the papillary muscles may be observed in other causes of mitral regurgitation, and it is not limited to patients with MVP. This study was to evaluate the association of LGE of the LV papillary muscles or ventricular wall on cardiac magnetic resonance imaging (CMR) and ventricular arrhythmia in patients with mitral regurgitation.Materials and MethodsThis study included 88 patients (mean age ± standard deviation, 58.3 ± 12.0 years; male, 42%) with mitral regurgitation who underwent CMR. They were allocated to the MVP (n = 43) and non-MVP (n = 45) groups, and their LGE images on CMR, clinical characteristics, echocardiographic findings, and presence of arrhythmia were compared.ResultsLV myocardial wall enhancement was more frequent in the MVP group than in the non-MVP group (28% vs. 11%, p = 0.046). Papillary muscle enhancement was observed in 7 (7.9%) patients. Of the 43 patients with MVP, 15 (34.8%) showed LGE in the papillary muscles or LV myocardium, including 12 (27.9%) with LV myocardial wall enhancement and 4 (9.3%) with papillary muscle enhancement. One patient with bilateral diffuse papillary muscle enhancement experienced sudden cardiac arrest due to ventricular fibrillation. Univariable logistic regression analysis showed that high systolic blood pressure (BP; odds ratio [OR], 1.05; 95% confidence interval [CI], 1.01–1.09; p = 0.027) and ventricular arrhythmia (OR, 6.84; 95% CI, 1.29–36.19; p = 0.024) were significantly associated with LGE of the papillary muscles.ConclusionLGE of the papillary muscles was present not only in patients with MVP, but also in patients with other etiologies of mitral regurgitation, and it was associated with high systolic BP and ventricular arrhythmia. Papillary muscle enhancement on CMR should not be overlooked.     

慢性缺血性二尖瓣关闭不全的外科治疗

目的：探讨慢性缺血性二尖瓣关闭不全（IMR）的手术治疗方法和效果。方法：2004-04~2008-09,冠脉搭桥同期外科治疗IMR 21例,其中中度反流17例,重度反流4例。二尖瓣成形术6例,其中使用人工瓣环4例。瓣膜置换术15例,其中双叶机械瓣8例、生物瓣7例。结果：全组手术死亡1例。17例术后平均随访24个月,远期死亡1例,生存者远期心功能l~Ⅱ级者16例,Ⅲ级者1例。术后超声复查左心室内径较术前明显缩小,瓣膜功能良好。结论：中度和中度以上缺血性二尖瓣关闭不全在作冠脉搭桥术时应同时手术处理病变的瓣膜,术后效果满意。而手术矫治的方法应根据瓣膜的病理改变和手术者的经验决定。     

外科治疗冠心病合并中度以上缺血性二尖瓣反流的早期效果分析

目的 探讨冠状动脉粥样硬化性心脏病伴中度以上缺血性二尖瓣反流经外科治疗后的早期疗效.方法 回顾性分析1999年12月-2010年12月行冠状动脉旁路移植术(CABG)治疗的175例冠心病合并中度以上缺血性二尖瓣反流患者的临床资料,根据手术方式分为单纯CABG组(108例)、CABG同期行二尖瓣成形/置换组(同期手术组,67例).比较两组的年龄、性别、搭桥支数、主动脉内球囊反搏(IABP)和心室辅助装置(VAD)使用情况、围术期死亡率、同时行其他手术(主动脉瓣置换、室壁瘤切除、室间隔缺损修补等)情况,并分析两组手术前后左房内径(LA)、左室舒张末内径(LVEDD)、左室射血分数(LVEF)、二尖瓣反流程度、肺动脉收缩压(sPAP)、心功能NYHA分级等的变化.结果 两组年龄、性别、搭桥支数、使用IABP和VAD、围术期死亡率、同时行其他手术情况差异均无统计学意义(P＞0.05).两组术后LA、LVEDD、二尖瓣反流程度、sPAP、心功能NYHA分级等均较术前明显改善(P＜0.01),而LVEF与术前比较差异无统计学意义(P＞0.05).结论 对于冠心病伴中度以上缺血性二尖瓣反流患者,全面而积极的手术干预并未带来更理想的早期手术效果;在充分再血管化的基础上,可选择简单而安全有效的手术方式.     

心肌梗死伴二尖瓣返流影响因素的心脏MR研究

目的:采用心脏磁共振成像探究伴或不伴二尖瓣返流的心肌梗死患者的左心室结构和功能差异,并分析可能促使心肌梗死患者发生二尖瓣返流的影响因素.方法:回顾性分析心肌梗死患者131例,并将其分为不伴二尖瓣返流组(56例)以及伴二尖瓣返流组(75例),分析比较两组的一般临床资料、左心室结构功能数据及钆对比剂延迟强化数据.结果:与不...     

Follow-up examination of 12 heart transplant recipients with cardiac CT

ObjectiveThe aims of this study were to observe the changes of a transplanted heart with cardiac computed tomography (CT) and to evaluate the clinical application of the examination.MethodsCardiac CT was performed on 12 heart transplant recipients, of which 4 cases were also examined by echocardiography. Coronary arteries, the cardiac chamber, and the wall were shown with three-dimensional imaging techniques, and their changes were analyzed and discussed.ResultsTwelve heart transplant recipients were successfully examined by CT. All transplanted hearts were found with good anastomosis at the great vessels and atria. Coronary allograft vasculopathy was found in 7 cases, of which 4 cases were found with ventricular dilation or ventricular septum thickening and 1 with tricuspid regurgitation. Ventricular dilation was found in other 3 cases, of which 1 was found with ventricular septum thickening and 1 with tricuspid regurgitation. No abnormality was found by cardiac CT in the rest 2 cases, which were found with mitral regurgitation by echocardiography.ConclusionCardiac CT can clearly and directly display the changes in the shape of a transplanted heart and coronary artery abnormalities. It will become an ideal noninvasive follow-up method for the heart transplant recipients.     

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.     

Quantification of three-dimensional left ventricular segmental wall motion and volumes from gated tomographic radionuclide ventriculograms

Tomographic radionuclide ventriculograms may be used for three-dimensional wall motion analysis. We propose that automatic quantification of these images is possible, and here we describe the implementation and validation of a method to perform this task. Automatic computer methods were developed to locate the left ventricular (LV) endocardial surfaces in all time frames of the cardiac cycle. Global, regional, and local motion and volume were computed. Results were displayed using three-dimensional graphics. The methods were validated using phantom, canine, and human studies. Actual phantom values correlated well with experimentally determined volumes, y = 1.01x + 1.29ml, r = 0.99. In the canine model, the LV endocardial surfaces were located to within an average of 1.9 mm and 3.7 mm at end-diastole and end-systole, respectively. Areas of obvious wall motion abnormalities in automatically processed patient studies corresponded well with angiographically documented coronary artery disease. End-diastolic and end-systolic volumes computed automatically from single photon emission computed tomography averaged errors of 9% and 38%, respectively, when compared with contrast ventriculographic volumes. These results indicate that it is possible to automatically identify the left ventricular endocardial surface in gated tomographic radionuclide ventriculograms. The location of these surfaces corresponds well with the location of implanted endocardial markers, and global volume computed from these surfaces corresponds well with known volumes.     

Automated ejection fraction determination from gated myocardial FDG-PET data

BACKGROUND: The aim of this study was to determine the potential of the automated calculation of the left ventricular ejection fraction from gated myocardial positron emission tomography (PET) scans. METHODS: We retrospectively analyzed the data of 20 patients who underwent both gated fluorine 18 deoxyglucose (FDG)-PET and equilibrium radionuclide angiography (ERNA). Gated PET data were analyzed by 2 independent programs (ie, quantitative gated single photon emission computed tomography [QGS]) originally developed for gated single photon emission computed tomography studies and functional polarmap (FPM) originally developed for the analysis of (functional) dynamic PET studies. ERNA data were used as the gold standard. RESULTS: Both QGS and FPM left ventricular ejection fraction results correlated highly with ERNA (y = 0.90 x x-5.9, r = 0.86, P < .0001; y = 0.80 x x+3.3, r = 0.84, P < .0001, respectively). The correlation between FPM and QGS left ventricular ejection fraction results was even higher (y = 0.89 x x+8.6, r = 0.97, P < .0001). Bland-Altman plots showed systematic differences in the left ventricular ejection fraction of -9.6% +/- 7.5% (QGS vs ERNA), -3.8% +/- 7.8% (FPM vs ERNA), and -5.8% +/- 3.5% (QGS vs FPM). Further comparison of the left ventricular volumes revealed systematic difference between QGS and FPM. Our results indicate that the correlation between the different left ventricular ejection fractions shows little sensitivity to errors in the left ventricular volumes; however, the exact relationship is influenced by these errors. CONCLUSION: It is concluded that the automated determination of the left ventricular ejection fraction from gated PET data has significant potential; its results are highly and significantly correlated with ERNA. However, the methods presented here require additional calibration before final accuracy and clinical applicability can be determined.     

Factor analysis of gated cardiac blood-pool data: application to patients with congenital heart disease.

Ventricular emptying was evaluated in patients with congenital heart disease (CHD) with left-to-right (L-R) shunt by factor analysis of gated equilibrium radionuclide angiography. In 36 (95%) of 38 ventricular septal defect patients and 20 (95%) of 21 atrial septal defect patients with small L-R shunt (pulmonary to systemic blood flow, Qp/Qs less than or equal to 2.5), as well as all patent ductus arteriosus patients, two significant cardiac factors corresponding to the ventricles (ventricular factor) and the atria plus large vessels (atrial factor) were extracted. However, in all of nine ventricular septal defect patients with large L-R shunt (Qp/Qs greater than 2.5), two different ventricular factors were determined which corresponded to the right and left ventricles (RV and LV). The RV factor showed a delay of ejection phase compared with the LV factor, and the delay was correlated with the value of Qp/Qs (r = 0.82, P less than 0.01). In eight (80%) of 10 ASD patients with large L-R shunt (Qp/Qs greater than 2.5), RV was described by the two different ventricular factors located in the septal and free-wall regions. The LV was extracted in the same factor as that located in the septal region of RV. This study demonstrates the capability of factor analysis in the pathophysiological investigation of CDH with L-R shunt.     

Quantification of mitral valve regurgitation by left ventricular volume and flow measurements using electron beam computed tomography: comparison with magnetic resonance imaging

PURPOSE: This study was designed to evaluate electron beam computed tomography (CT) for quantifying mitral regurgitation in comparison with magnetic resonance (MR) imaging as a reference method. METHOD: Forty-three patients, among them 33 with known mitral regurgitation, underwent electron beam CT and MR imaging. Total left ventricular stroke volume (TSV), antegrade stroke volume (ASV), and mitral regurgitation volume (MRV) and fraction (MRF) were determined and compared between the two modalities. Additionally electron beam CT measurements were compared with the corresponding echocardiographic findings. RESULTS: Significant differences between electron beam CT and MR imaging were found for measurements of TSV and MSV but not for ASV and MRF. There was a close linear correlation between both modalities for all parameters. Furthermore, there was good agreement between electron beam CT and echocardiography, although electron beam CT shows a tendency to overestimate mitral regurgitation slightly. CONCLUSION: The results indicate that electron beam CT offers an additional procedure for quantifying mitral regurgitation and that it may be used as an alternative to MR imaging.     

Validation of a new counts-based gated single photon emission computed tomography method for quantifying left ventricular systolic function: Comparison with equilibrium radionuclide angiography

Background  Because myocardial wall thickness is smaller than the spatial resolution of single photon emission computed tomography (SPECT) imaging, changes in myocardial wall thickness are related to changes in maximum pixel counts via the partial volume effect, allowing for quantification of regional systolic wall thickening. We have developed a new gated SPECT method for computing the global left ventricular ejection fraction (LVEF) based entirely on changes in maximum regional myocardial counts during systolic contraction. This new method is independent of endocardial edge detection or other geometric measurements. Methods and Results  In 23 patients the gated SPECT method was validated by comparison with radionuclide angiography. The correlation between computed LVEFs was excellent (slope=0.97, r=0.91). The measurement of LVEF by gated SPECT was highly reproducible, with minimal intraoperator (slope=0.97, r=0.97) or interoperator (slope=1.00, r=0.97) variability. Measurements of regional thickening indexes were also reproducible, with a mean intraoperator correlation coefficient of 0.89±0.05 (range 0.79 to 0.95) for the 14 myocardial regions. Finally, the measurement of LVEF was not significantly influenced by changes in reconstruction filter parameters over a range of cutoff frequencies from 0.16 to 0.28. Conclusions  This new counts-based gated SPECT method for measuring global left ventricular systolic function correlates well with radionuclide angiography, is highly reproducible, and has theoretic advantages over geometric methods. Supported by a grant from the American Heart Association, Virginia Affiliate, Inc., and by a grant from DuPont Pharma Radiopharmaceuticals, N. Billerica, Mass.     

Cardiac phase contrast gradient echo MRI: characterization of abnormal left ventricular wall motion in patients with ischemic heart disease

PURPOSE: In our patient study, we examined the clinical usefulness of phase contrast velocity mapping for the detection and characterization of localized abnormalities of left ventricular motion. MATERIALS AND METHODS: Velocity encoding is based on the fact that motion in the presence of a magnetic field gradient causes a change of the phase of the MRI signal that is proportional to the velocity of tissue motion. Left ventricular motion was characterized by parameters describing rotation and contraction/dilatation, respectively. We examined 34 patients with localized abnormalities of left ventricular motion due to ischemic heart disease. RESULTS: Three patients could not be sufficiently evaluated due to technical problems including varying positions of the heart during successive breathhold periods. In 27 of the remaining 31 patients, MRI could demonstrate abnormal radial velocities that corresponded fully or partly with perfusion deficits in single photon emission computed tomography or positron emission tomography. The abnormalities were most pronounced in early diastole. Rotational velocities did not show any regional changes. CONCLUSION: Our study showed that our technique is suitable for the detection and characterization of localized abnormalities of left ventricular motion in patients with ischemic heart disease.     

Detection of pulmonary emboli in dogs: comparison of single photon emission computed tomography, gamma camera imaging, and angiography

Single photon emission computed tomography (SPECT) allows separation of radionuclide activity in front of and behind the area of interest and results in more contrast than can be achieved using conventional gamma camera imaging. To determine if this improved contrast is of value in the detection of perfusion abnormalities in the lung, the lower lobe segmental pulmonary arteries of six dogs were embolized and pulmonary perfusion was evaluated using SPECT, conventional gamma camera imaging, and angiography. Although selective segmental angiography was the most sensitive method of detecting emboli, SPECT was much more sensitive than the gamma camera examination in evaluating the effects of the emboli at two hours and one, two, and eight weeks after embolization.     

Cardiovascular system function in mitral valve prolapse in fighter pilots]

Echocardiogram examination of 250 young fighter pilots has revealed that 15 aviators had mitral valve prolapse (MVP) without symptoms of pronounced regurgitation. Their functional indexes of cardiovascular system at rest or dosed physical load at veloergometer tests were normal. Only in 3 pilots were marked rare supraventricular or ventricular extrasystoles during ECG monitoring or veloergometria. Performance capability of all pilots was sufficient. 13 pilots with MVP in examination of their tolerance to +Gz hypergravity at the levels of 6 G or more for 15 s had frequent polytop or group ventricular extrasystole. There was an ordinary aggravation of extrasystole in aviators with more deep and bilateral MVP. The article makes a conclusion that on the basis of medical flight expertise a thorough selection must be made concerning possibility of every pilot with MVP to carry out flight at high manoeuvring aircraft of new generation taking into account the gravity of prolapse and tolerance to high +Gz hypergravity more than 5 G.