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.     

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.     

Validation of planar and tomographic radionuclide ventriculography by a dynamic ventricular phantom

Although there is increasing interest in the automatic processing of tomographic radionuclide ventriculography (TRV) studies, validation is mainly limited to a comparison of TRV results with data from planar radionuclide ventriculography (PRV) or gated perfusion single photon emission computed tomography (SPECT). The aim of this study was to use a dynamic physical cardiac phantom to validate the ejection fraction (EF) and volumes from PRV and TRV studies. A new dynamic left ventricular phantom was constructed and used to obtain 21 acquisitions in the planar and tomographic mode. The directly measured volumes and EFs of the phantom during the acquisitions were considered as the gold standard for comparison with TRV and PRV. EFs were calculated from PRV by background-corrected end-diastolic and end-systolic frames. Volumes and EFs were calculated from TRV by region growing with different lower thresholds to search for the optimal threshold. EF from PRV correlated significantly with the real EF (r=0.94, P=0.00). The optimal threshold value for volume calculation from TRV in 336 cases was 50% (r=0.98, P=0.00) yielding the best slope after linear regression. When considering these calculated end-diastolic and end-systolic volumes, EF correlated well (r=0.99, P=0.00) with the real EF, and this correlation was significantly (P=0.04) higher than that of the EF from PRV. Our experiments prove that EF measured by TRV yields more accurate results compared with PRV in dynamic cardiac phantom studies.     

Comparison of biventricular ejection fractions using cadmium-zinc-telluride SPECT and planar equilibrium radionuclide angiography

Background

We compared biventricular ejection fractions (EFs) from gated blood-pool single-photon emission computed tomography (SPECT) using a cadmium-zinc-telluride camera (CZT-SPECT) with planar equilibrium radionuclide angiography (ERNA) using a NaI gamma camera (NaI-planar). We also evaluated whether imaging time can be reduced without compromising image quality using the CZT camera.

Methods

Forty-eight patients underwent NaI-planar and CZT-SPECT on the same day. CZT-SPECT datasets were re-projected at an LAO orientation similar to ERNA acquisition, forming CZT-repro planar datasets. The resulting biventricular volumetric measurements and EFs were compared.

Results

LVEF calculated from CZT-SPECT and CZT-repro correlated better with NaI-planar (r = 0.93 and 0.99, respectively) than RVEF (r = 0.76 and 0.82, respectively). Excellent intra-class correlation and low bias in intra-observer comparisons were observed for the biventricular EFs derived from three datasets. A wider limit of agreement in CZT-SPECT-derived LVEFs, lower correlation and significant bias for NaI-planar, and CZT-repro-derived RVEFs was found in the inter-observer analyses. Nonetheless, the imaging time can be reduced to 4 minutes without increasing variability in EFs using the CZT camera (P = NS).

Conclusions

LVEFs calculated from CZT-SPECT and CZT-repro correlated well with NaI-planar. CZT camera may reduce imaging time while preserving image quality in the assessment of biventricular EFs.

     

Agreement between four available algorithms to evaluate global systolic left and right ventricular function from tomographic radionuclide ventriculography and comparison with planar imaging

BACKGROUND AND AIM: Left and right ventricular ejection fractions (LVEF and RVEF) and end-diastolic and end-systolic volumes (LVEDV, RVEDV, LVESV and RVESV) can be calculated from tomographic radionuclide ventriculography (TRV). The aim of this study was to validate and compare these parameters obtained using four different TRV software programs (QBS, QUBE, 4D-MSPECT and BP-SPECT). METHODS: LVEF obtained from planar radionuclide ventriculography (PRV) was compared with LVEF obtained from TRV using the four different software programs in 166 patients. Furthermore, ventricular volumes obtained using TRV (QBS, QUBE and 4D-MSPECT) were compared with those obtained using BP-SPECT, the latter being the only method with the validation of ventricular volumes in the literature. RESULTS: The correlation of LVEF between PRV and TRV was good for all methods: 0.81 for QBS, 0.79 for QUBE, 0.71 for 4D-MSPECT and 0.79 for BP-SPECT. The mean differences+/-standard deviation (SD) were 3.16+/-9.88, 10.72+/-10.92, 3.43+/-11.79 and 2.91+/-10.39, respectively. The correlation of RVEF between BP-SPECT and QUBE and QBS was poor: 0.33 and 0.38, respectively. LV volumes calculated using QBS, QUBE and 4D-MSPECT correlated well with those obtained using BP-SPECT (0.98, 0.90 and 0.98, respectively), with mean differences+/-SD of 7.31+/-42.94, -22.09+/-36.07 and -40.55+/-39.36, respectively. RV volumes showed poorer correlation between QBS and BP-SPECT and between QUBE and BP-SPECT (0.82 and 0.57, respectively). CONCLUSION: LVEF calculated using TRV correlates well with that calculated using PRV, but is not interchangeable with the value obtained using PRV. Volume calculations (for left and right ventricle) and RVEF require further validation before they can be used in clinical practice.     

Impact of radionuclide ventriculography prior to elective abdominal aortic reconstruction

We evaluated how preoperative radionuclide ventriculography (RNV) influences the clinical management of 96 patients referred for elective infrarenal abdominal aortic surgery. Of these, 11 had aortoiliac occlusive disease and 85 an abdominal aortic aneurysm. In 89 patients (93%), there was a known history or clinical evidence of coronary artery disease prior to RNV. The scan was abnormal in half the patients. There were 56 patients with left ventricular ejection fraction (LVEF) > 50% and 40 with LVEF < or = 50%. The LVEF ranged between 10% and 88% with a mean of 52.8+/-14.1%. There was normal wall motion in 56 patients and wall abnormalities were present in 40, including four LV aneurysms. After initial assessment, 19 patients did not proceed to surgery for a variety of reasons. Cardiology consultation was requested in 11 patients, six of which were delayed or turned down for surgery mainly on cardiac grounds. Only one of these underwent cardiac catheterization. Of the remaining 77 patients who underwent surgery, 15 were seen by a cardiologist and one was delayed in order to optimize his cardiac status. No patient underwent prophylactic coronary angioplasty/stenting or revascularization preoperatively. In addition, based on the RNV results and in conjunction with the clinical findings, six patients had pulmonary artery catheters inserted either the night prior to operation (n = 3) or after induction to anaesthesia (n = 3). This is the largest reported British series of cardiac testing using RNV prior to abdominal aortic surgery. Coronaryartery disease is very common amongst such patients. RNV influences our decision-making and patientselection. An abnormal result may alter the clinical management, lead to a cardiology referral (26/96, 27% in this series) and have anaesthetic implications.     

Intravenous streptokinase therapy in acute myocardial infarction: Assessment of therapy effects by quantitative 201Tl myocardial imaging (including SPECT) and radionuclide ventriculography

To evaluate a potential beneficial effect of systemic streptokinase therapy in acute myocardial infarction, 36 patients treated with streptokinase intravenously were assessed by radionuclide ventriculography and quantitative ²⁰¹Tl myocardial imaging (including SPECT) in comparison with 18 conventionally treated patients. Patients after thrombolysis had significantly higher EF, PFR, and PER as well as fewer wall motion abnormalities compared with controls. These differences were also observed in the subset of patients with anterior wall infarction (AMI), but not in patients with inferior wall infarction (IMI). Quantitative ²⁰¹Tl imaging demonstrated significantly smaller percent myocardial defects and fewer pathological stress segments in patients with thrombolysis compared with controls. The same differences were also found in both AMI and IMI patients. Our data suggest a favorable effect of intravenous streptokinase on recovery of left ventricular function and myocardial salvage. Radionuclide ventriculography and quantitative ²⁰¹Tl myocardial imaging seem to be reliable tools for objective assessment of therapy effects.     

Right ventricular ejection fraction measured by multigated planar equilibrium radionuclide ventriculography is an independent prognostic factor in patients with ischemic heart disease

Background

The number of studies on the prognostic value of the right ventricular ejection fraction (RVEF) in patients with ischemic heart disease (IHD) is limited, whereas it is widely accepted that the left ventricular ejection fraction (LVEF) is a strong prognostic factor. We assessed whether RVEF measured by multigated planar equilibrium radionuclide ventriculography (RNV) is an independent prognostic factor in patients with IHD.

Methods and Results

We retrospectively identified 347 consecutive patients with IHD (mean age 71?±?11?years; 18% women) who underwent multigated planar equilibrium RNV between 2004 and 2008 to determine the LVEF, which also provided the RVEF (mean 44.7%?±?11.0%). We categorized patients according to RVEF in ??40% (n?=?240) and <40% (n?=?107). Patients were followed for a median of 826?days (range 3-2,400) for the occurrence of events [all-cause mortality (n?=?60), cardiac mortality (n?=?33), and cardiac hospitalization (n?=?78)]. Cox regression analysis with significant univariate predictors [coronary artery revascularization (P?=?.003), diuretics (P?=?.03), and statins (P?<?.001)] showed that an RVEF <40% was associated with a 2.90 (1.68-5.00)-fold higher risk of all-cause death. Accordingly, a decreased RVEF was associated with a 2.15 (1.34-3.43)-fold increase in the risk of cardiac hospitalization and a 5.11(2.32-11.23)-fold risk of cardiac death.

Conclusion

RVEF measured by multigated planar equilibrium RNV is an independent prognostic factor in patients with chronic IHD.     

A technique for the simulation of planar radionuclide images of the kidney

BACKGROUND: Although Tc-dimercaptosuccinic acid (DMSA) scans are routinely used to quantify relative renal function, no quantification method is universally adopted. Audits using real patient data indicate reasonable consistency but, as the true relative function is unknown, accuracy cannot be assessed. The aim was to simulate realistic DMSA images that can be used to assess accuracy. METHODS: Anatomical models were created from computed tomography (CT) scans of a patient who had also undergone DMSA imaging. Organs that take up DMSA were outlined on CT and each assigned an activity concentration (with renal cortex and medulla modelled separately). The simulated images were visually compared to the patient's clinical images and subtracted to identify differences. Iteration was used on the posterior image to find the organ activities that produced the most realistic simulated image. The optimal activity distribution was then used to also simulate an anterior image. To assess the simulations, the percentage difference was calculated between the counts in each kidney on the real and simulated images. RESULTS: Visually, the clinical and simulated images appear similar and the subtracted images indicate only small differences. The percentage difference in kidney counts between the images was less than 1% for both kidneys on the posterior image and less than 5% on the anterior image. The cortex and medulla activity concentrations were approximately equal. CONCLUSION: A technique for realistic simulation of DMSA images has been devised and should prove useful for evaluating image analysis software.     

Accuracy of commercially available processing algorithms for planar radionuclide ventriculography using data for a dynamic left ventricular phantom

BACKGROUND: Automatic and semi-automatic algorithms to calculate ejection fraction (EF) from planar radionuclide ventriculography (PRV) have been used for many years in nuclear medicine. Validation of these algorithms is scarce and often performed on outdated versions of the software. Nevertheless, clinical trials where PRV is being used as the 'gold standard' for EF are numerous. Because of the importance attributed to the EF calculated by these programs, the accuracy of the resulting EF was assessed with a dynamic left ventricular physical phantom. METHODS: A dynamic left ventricular phantom was used to simulate 21 combinations of various ejection fractions (7-66%) and end diastolic volumes (27-290 ml). For each combination, a planar radionuclide ventriculograph was acquired, converted to an interfile format and transferred into processing stations with 10 different contemporaneously available commercial algorithms. The gold standard was the 'real' EF of the phantom, derived from the exact volume of the ventricle in end diastolic and end systolic position. Correlation and Bland-Altman analysis was performed between the real EF and the calculated EF. RESULTS: The correlation for all data was excellent (r=0.98), the mean difference was very acceptable (0.98%). Nevertheless, Bland-Altman analysis showed a significant trend in the difference between real and calculated EF, with a growing underestimation for higher ranges of EF, due to an overestimation of background in larger volumes compared to smaller ones. CONCLUSION: The determination of EF from PRV, calculated with commercially available algorithms, correlates closely to the real EF of a dynamic left ventricular phantom. This phantom can be used in the development and validation of algorithms for PRV studies, in software audits and in quality assurance procedures.     

Identification of right ventricular rupture by radionuclide ventriculography

Right ventricular rupture is rare. We report its identification by radionuclide ventriculography and subsequent confirmation by contrast angiography and at operation. The aetiology in this case was a primary cardiac malignancy.     

Role of radionuclide ventriculography in evaluating cardiac function

The role of nuclear cardiology techniques for evaluating cardiac function has become increasingly important among other diagnostic techniques. The current status of radionuclide imaging of left and right ventricular function allows accurate diagnosis of cardiac patients with both coronary and noncoronary disease. The combination of gated first-pass and equilibrium radionuclide ventriculography makes it possible to assess more completely cardiac function than by either technique alone. Of particular interest to most imaging physicians is the current position of exercise ventriculography in the diagnostic setting, especially since this test has undergone new scrutiny in its application to broader patient segments. This technique and issues related to its place in the diagnostic environment are discussed in this review article, with emphasis on relevance to the clinical laboratory.     

Comparison of interstudy reproducibility of equilibrium electrocardiography-gated SPECT radionuclide angiography versus planar radionuclide angiography for the quantification of global left ventricular function

BACKGROUND: Electrocardiography-gated single photon emission computed tomography (SPECT) radionuclide angiography (RNA) provides accurate measurement of both left ventricular (LV) ejection fraction (EF) and end-diastolic and end-systolic volumes. In this study we studied the interstudy precision and reliability of SPECT RNA as compared with planar RNA for the measurement of global systolic LV function. METHODS AND RESULTS: The population included 10 patients with chronic coronary artery disease having 2 sets of acquisitions, each consisting of planar and SPECT RNA. SPECT RNA was processed with SPECT-QBS and SPECT-35%. (For SPECT-35%, a manual segmentation method based on the 35% threshold of the maximum LV cavity activity is used to provide estimates of the number of voxels and the activity included in the LV cavity. The calculated LV number of voxels is then used to calculate LV volume measurement. The LV EF is calculated as the ratio of LV end-diastolic and end-systolic activity.) For LV EF, end-diastolic volume, and end-systolic volume, the interstudy precision, as reflected by the correlation coefficient, coefficient of variability, coefficient of repeatability, and within-subject coefficient of variation, and the interstudy reliability, as reflected by the intraclass correlation coefficient, were best with SPECT-35%, followed by planar RNA and then SPECT-QBS, respectively. The sample size needed to objectify a change in a parameter of LV function is lowest with SPECT-35%, followed by planar RNA and then SPECT-QBS, respectively. CONCLUSIONS: The SPECT-35% processing method provides excellent interstudy precision and reliability for LV function measurement. In this aspect it seems to be better than planar RNA and SPECT-QBS. These results need to be confirmed in a larger patient population.     

Assessment of left ventricular diastolic function: comparison of contrast ventriculography and equilibrium radionuclide angiography.

Twenty-two patients with coronary artery disease were studied first by radionuclide angiography (RNA) and then by contrast ventriculography. Cardiac medications were discontinued at least 72 hr before study. The patients were studied during atrial pacing at heart rates close to their spontaneous sinus rhythm. Contrast ventriculography was performed at 50 frames/sec in the 30 degrees right anterior oblique projection using 40 ml of a nonionic contrast medium (iopamidol) at a flow rate of 10-12 ml/sec. The contours of the left ventricular silhouette at contrast ventriculography were traced, frame by frame, on a graphic table with a digitizing penlight. Equilibrium 99mTc RNA was performed in the best septal 45 degrees left anterior oblique projection, acquiring 150,000 cts/frame, at 50 frames/sec and with a 5% gate tolerance. Time-activity curves from both end-diastolic and end-systolic ROIs were built and interpolated. Both RNA and contrast ventriculography volume curves were filtered with Fourier five harmonics. A close relationship was found between RNA and contrast ventriculography measurements of peak filling rate normalized to end-diastolic cps (r = 0.87, p less than 0.001) and stroke count (r = 0.87, p less than 0.001), ejection fraction (r = 0.94, p less than 0.001). Thus, in patients with coronary artery disease, LV filling can be accurately assessed using RNA.     

Quantitative evaluation of the phase image in radionuclide ventriculography

A functional image is a representation that enhances a particular characteristic of organ behaviour (feature enhancement) with a concomitant reduction or elimination of other informations. The functional image of phase (PI), obtained by Fourier analysis, may be interpreted to represent the onset of counts reduction or contraction in each region of the heart. Phase Spreading (PS), is a parameter derived from PI and represents ventricular temporal behaviour including some spatial information. Phase analysis and PS are very sensitive tools in the diagnosis and characterization of cardiac pathology. PS is a specific indicator of CAD, allows the introduction of normal ranges and is an example of quantitative evaluation of functional images.     

放射性核素心脏显像对SLE患者的临床应用

目的评价系统性红斑狼疮（ＳＬＥ）患者左心室功能。方法用平衡法门电路心室显像及心肌显像测定２０例正常人和３０例ＳＬＥ患者左室收缩和舒张功能。结果ＳＬＥ患者左室射血分数、相角程、高峰射血率、高峰充盈率分别为０５２±０１１、６０８９±１２１２°、３０８±０４８ＥＤＶ／ｓ和２８８±０４７ＥＤＶ／ｓ；正常对照组分别为０６８±００２、５３２５±５２６°、３６６±０５１ＥＤＶ／ｓ和３３４±０８８ＥＤＶ／ｓ。两组比较，ｔ值分别为４５０、３１１、５８０和４６０，Ｐ均＜００１。阳性率为４８６％，心肌显像阳性率为６４％；放射性核素心脏显像检测ＳＬＥ心肌损害的灵敏度为６３％，特异性为８５％。结论放射性核素心脏显像可以客观评价ＳＬＥ患者左心室功能，对发现ＳＬＥ心肌损害及指导治疗有一定意义。