Value of combined assessment of global and segmental ventricular contraction with right anterior oblique ECG-gated first-pass and left anterior oblique equilibrium radionuclide ventriculography

A semi-automated, variable-region-of-interest method of analysis was used to measure both global and segmental left ventricular (LV) and global right ventricular (RV) contraction with ECG-gated first-pass and equilibrium radionuclide ventriculography. Normal values were defined in 20 healthy volunteers, and in 24 symptomatic patients, the results were compared with right anterior oblique (RAO) contrast left ventriculography. The global LV ejection fraction (LVEF) obtained by equilibrium imaging in the left anterior oblique (LAO) projection correlated closely with the results obtained by the gated first-pass method in the RAO projection (r = 0.95) and those obtained with contrast left ventriculography (r = 0.94); furthermore, the interobserver variability was small (r = 0.985). The normal values for LVEF obtained using radionuclide techniques and contrast ventriculography did not differ, but with the equilibrium radionuclide method, the RV ejection fraction (RVEF) values were underestimated in comparison to those obtained by the RAO gated first-pass technique. In five patients with localised inferior segmental akinesis at contrast angiography, the RAO first-pass cine display demonstrated a corresponding wall-motion abnormality in all cases, but LAO equilibrium cine displays did so in only one out of five patients. For segmental quantitation of LV contraction, a computer programme defined the ventricular edge, divided the RAO LV images into five segments and determined both the segmental area contraction (SAC) and the counts-based segmental ejection fraction (SEF). Radionuclide SAC measurements correlated very strongly with SEF measurements (r = 0.94-0.99). Both radionuclide SAC and radionuclide SEF correlated well with contrast angiographic SAC, except in the inferobasal segment.(ABSTRACT TRUNCATED AT 250 WORDS)     

Right anterior oblique first-pass radionuclide ejection fractions: effects of temporal smoothing and various background corrections

Thirty-seven patients undergoing contrast left ventriculography were studied by first-pass radionuclide angiography (FPRA) in the right anterior oblique view. Ejection fraction (LVEF) was calculated from FPRA using (a) a spatially and temporally varying background correction (BGC) based on a matrix of activity in lung and left atrium and (b) BGC with temporal fluctuation but with no allowance for spatial variations. The two methods were performed on both raw and temporally smoothed data. All four LVEFs correlated well with contrast LVEF (r = 0.90 - 0.94). Absolute values differed significantly from contrast values except for the method using the spatially and temporally varying BGC on smoothed data, which provided the closest overall agreement at all levels of LVEFs, despite occasional large individual variations. The same method on raw data overestimated low LVEFs and the method applying only temporal fluctuation in background underestimated high LVWFs. Allowance for spatial and temporal variations in background is therefore important when first-pass radionuclide angiography is performed in the RAO view.     

Comparison between vertical parallel hole collimator and 30° rotating slant hole collimator for assessing global and regional left ventricular function by radionuclide angiography

Left ventricular ejection fraction (LVEF) and regional wall motion abnormalities were determined in 40 patients (30 with coronary artery disease and 10 with valvular heart disease) using equilibrium radionuclide angiography. Scintigraphic acquisitions were collected in random order with 2 different collimators as follows: in anterior face (AF), left anterior oblique (25°–45° LAO) and 70° LAO, with a vertical parallel hole collimator (VTC), and in 25°–45° LAO and 65°–80° LAO with a 30° rotating slant hole collimator (RSHC), with the slant of the collimator directed towards the cardiac apex in both projections. Results were compared to contrast ventriculography (CV) performed in the 30° right anterior view (3 segments: anterior, apical, inferior) and in a 60° left anterior oblique view (3 segments: septal, apical and lateral). Radionuclide LVEF in both series was closely correlated with contrast ventriculographic LVEF (r=0.89, VTC vs CV and r=0.87, RSHC vs CV, respectively). Regional wall motion analysis was only performed among the 30 patients suffering from coronary heart disease. Eight contrast angiographic studies were normal and 22 abnormal. Global sensitivity and specificity were 100% and 63% with the VTC (3 false positives) and 91% and 87% with the 30° RSHC (2 false negatives and 1 false positive, P=ns). Agreement for the localisation of the regional wall motion abnormalities between CV and radionuclide angiography was 70.6% with the VTC and 71.2% with the RSHC (P=ns). Intensity of the regional wall motion abnormalities was assessed with the 30° RSHC as well as with the VTC (r=0.7 score CV vs score VTC and r=0.8 score CV vs score RSHC, P=ns). We conclude that the use of a rotating slant hole collimator associated with radionuclide ventriculography allows reliable determination of left ventricular ejection fraction and accurate assessment of regional wall motion abnormalities with only two projections while the vertical collimator requires three.     

Localization of exercise-induced myocardial ischemia with single view and biplanar radionuclide ventriculography: validation in single vessel coronary disease

The ability of single view and biplanar radionuclide ventriculography (RVG) to determine the location of myocardial ischemia during maximal graded supine bicycle exercise was assessed in 50 patients with chest pain, no prior myocardial infarction, and a single coronary stenosis of greater than or equal to 50% luminal diameter narrowing at coronary angiography. A biplane collimator was used so that both right anterior oblique (RAO) gated first-pass and left anterior oblique (LAO) equilibrium RVG could be performed at rest and exercise. Results were compared with those obtained using 4-view 201Tl myocardial scintigraphy in the same patients. Regional wall motion abnormalities (WMA) and 201Tl perfusion defects were detected and assigned to individual coronary vessels by agreement between at least two of three independent observers, who read all studies blinded along with those from control subjects with chest pain but no angiographically significant coronary artery disease. When scintigraphic abnormalities were detected, both biplanar RVG (36/39 = 92%) and 201Tl (25/25 = 100%) were more frequently correct in predicting the stenosed vessel than single view LAO RVG (24/32 = 75%) (P less than 0.05). At RVG only inferior WMA, in the RAO view, predicted right coronary stenosis. Only posterolateral WMA, in the LAO view, predicted left circumflex stenosis. Thus biplanar, but not single view, LAO exercise RVG is a reasonable alternative to exercise 201Tl for localizing exercise-induced ischemic abnormalities to individual coronary stenoses.     

Localization of exercise-induced myocardial ischemia with single view and biplanar radionuclide ventriculography: validation in single vessel coronary disease

The ability of single view and biplanar radionuclide ventriculography (RVG) to determine the location of myocardial ischemia during maximal graded supine bicycle exercise was assessed in 50 patients with chest pain, no prior myocardial infarction, and a single coronary stenosis of 50% luminal diameter narrowing at coronary angiography. A biplane collimator was used so that both right anterior oblique (RAO) gated first-pass and left anterior oblique (LAO) equilibrium RVG could be performed at rest and exercise. Results were compared with those obtained using 4-view ²⁰¹Tl myocardial scintigraphy in the same patients. Regional wall motion abnormalities (WMA) and ²⁰¹Tl perfusion defects were detected and assigned to individual coronary vessels by agreement between at least two of three independent observers, who read all studies blinded along with those from control subjects with chest pain but no angiographically significant coronary artery disease. When scintigraphic abnormalities were detected, both biplanar RVG (36/39=92%) and ²⁰¹Tl (25/25=100%) were more frequently correct in predicting the stenosed vessel than single view LAO RVG (24/32=75%) (P<0.05). At RVG only inferior WMA, in the RAO view, predicted right coronary stenosis. Only posterolateral WMA, in the LAO view, predicted left circumflex stenosis. Thus biplanar, but not single view, LAO exercise RVG is a reasonable alternative to exercise ²⁰¹Tl for localizing exercise-induced ischemic abnormalities to individual coronary stenoses.This work was supported by a Postgraduate Medical Research Scholarship from the National heart Foundation of Australia (Canberra), and by the Alfred Hospital Whole Time Medical Specialists (Melbourne)     

The two-view radionuclide ventriculogram. Advantages of the LPO view.

This report is a prospective study of 33 male patients who underwent both contrast ventriculography (CVG) and radionuclide ventriculography (RVG) within a 24-hour period. Expert, blinded observers graded the left ventricle's regional wall motion (RWM) in the left anterior descending (LAD), left circumflex (LCx), and posterior descending arterial (PDA) distributions on right anterior oblique (RAO), and left anterior oblique (LAO) CVGs, and on anterior (ANT), LAO, 70 degrees left anterior oblique (LAO70), and left posterior oblique (LPO) RVGs. When statistically compared with CVG RWM standard data, RVG studies composed of LAO and LPO views were equal to the RVG studies composed of ANT, LAO, and LAO70 views in assessment of the LAD and LCx distributions. The RVG with LAO and LPO views was superior to the RVG with ANT, LAO, LAO70 in the detection of the posterior descending artery RWM. The authors conclude that accurate assessment of RWM is efficiently performed with the RVG composed of LAO and LPO views.     

Videodensitometric ejection fractions from intravenous digital subtraction left ventriculograms: correlation with conventional direct contrast and radionuclide ventriculography

Forty-three patients who had undergone direct-contrast ventriculography were submitted to intravenous digital subtraction ventriculography and first-pass radionuclide ventriculography to compare the left ventricular ejection fractions obtained by each method. Ejection fractions were calculated by the area-length method from the direct contrast ventriculograms, by both area-length and videodensitometric methods from the digital subtraction ventriculograms, and by count densitometry from the radionuclide ventriculograms. Satisfactory correlations were found between values obtained by the late mask resubtracted videodensitometric method and the radionuclide method (r = 0.85) and by the digital ventriculographic area length method and direct-contrast method (r = 0.88). Videodensitometric methods may be an alternative way to estimate left ventricular ejection fractions accurately without reliance on geometric assumptions about the shape of the left ventricular cavity.     

Radionuclide ventriculography: evaluation of automated and visual methods for regional wall motion analysis

Regional wall motion (RWM) abnormalities are sensitive indicators of left ventricular (LV) dysfunction, but quantitation of RWM with gated radionuclide ventriculography (RVG) has been limited, particularly in the left anterior oblique (LAO) projection. Regional LV performance was studied in 18 patients undergoing LAO RVG immediately prior to contrast ventriculography (CVG). Wall motion was analyzed by semiautomated and visual methods using several coordinate systems. For semiautomated methods, RVG and CVG wall motion were closely related in the two 90 degrees polar sectors at the apex and posterior wall (r = .85) and in the five 45 degrees polar sectors from midseptum through posterior wall (r = .82). The basal sectors on RVG had weak relationship to CVG, due to adjacent vascular structures. Semiautomated and visual grades for polar sectors on both CVG and RVG were closely related (r = .88- .94). Measured regional wall motion on LAO RVG compared favorably with near-simultaneous CVG in nonoverlapping portions of the LV and allowed objective quantitation of regional LV performance.     

Evaluation of left ventricular wall motion and function in patients with previous myocardial infarction by three-dimensional99mTc-HSAD multigated cardiac pool imaging

To evaluate left ventricular (LV) wall motion stereoscopically from all directions and to calculate the LV volume by three-dimensional (3D) imaging,^99mTc-DTPA human serum albumin-multigated cardiac pool-single photon emission computed tomography (^99mTc-MUGA-SPECT) was performed. A new data processing program was developed with the Application Visualization System-Medical Viewer (AVS-MV) based on images obtained from^99mTc-MUGA-SPECT. In patients with previous myocardial infarction, LV function and LV wall motion were evaluated by 3D-^99mTc-MUGA imaging. The LV end-diastolic volume (LVEDV) and end-systolic volume (LVESV) were obtained from 3D-^99mTc-MUGA images by the surface rendering method, and the left ventricular ejection fraction (LVEF) was calculated at thresholds of 35% (T1), 40% (T2), 45% (T3), and 50% (T4). There was a strong correlation between the LV volume calculated by 3D-^99mTc-MUGA imaging at a threshold of 40% and that determined by contrast left ventriculography (LVEDV: 194.7 ± 36.0ml vs. 198.7 ± 39.1ml, r = 0.791, p < 0.001; LVESV: 91.6 ± 44.5ml vs. 93.3 ± 41.3ml, r = 0.953, p < 0.001), respectively. When compared with the LVEF data obtained by left ventriculography, significant correlations were found for 3D images reconstructed at each threshold (T1: r = 0.966; T2: r = 0.962; T3: r = 0.958; and T4: r = 0.955). In addition, when LV wall motion obtained by 3D-^99mTc-MUGA imaging (LAT and LAO views) was compared with the results obtained by left ventriculography (RAO and LAO views), there was good agreement. 3D-^99mTc-MUGA imaging was superior in allowing evaluation of LV wall motion in all directions and in assessment of LV function, since data acquisition and image reconstruction could be done within a short time with the three-detector imaging system and AVS-MV. This method appears to be very useful for the observation of both LV wall motion and LV function in patients with ischemic heart disease, because it is a noninvasive examination.     

Clinical utility of a multigated modified anterior projection in the detection of left ventricular inferior and apical wall motion abnormalities

Recent evidence indicates that the left anterior oblique projection (LAO) multigated radionuclide ventriculogram (RVG) underestimates presence and extent of apical and inferior left ventricular (LV) wall motion abnormalities. We investigated, prospectively, the sensitivity and specificity of a modified anterior projection (MAP), which incorporates cephalad tilting. Thirty-three consecutive patients undergoing cardiac catheterization suspected to have coronary artery disease were studied with RVG, using both the MAP and LAO views. LAO views were analyzed using the ejection fraction image (REFI), and the regional ejection fraction (REF) of the inferoapical region. The MAP studies were analyzed using stroke volume image (SVI) to evaluate apical and inferior LV regions. Results were as follows: (Formula: see text), Both intraobserver and interobserver variabilities were comparable to those of conventional angiographic studies used in detection of apical and inferior asynergy. It is concluded that the multigated MAP offers additional information about abnormalities of the LV inferior and apical regions.     

Left ventricular dimensions during isometric exercise in aortic valve incompetence assessed by M-mode echocardiography and gated equilibrium radionuclide angiography

We compared M-mode echocardiographic and gated equilibrium radionuclide angiography assessement of the left ventricular (LV) dimensions at rest and during isometric exercise in 18 patients with chronic aortic valve incompetence. The two methods showed a satisfactory correlation when comparing LV size at rest and during exercise (LV end-diastolic dimension in echocardiography vs LV end-diastolic volume in radionuclide angiography, r=0.80, P0.01 at rest and r=0.81, P0.01 during exercise; LV end-systolic dimension in echocardiography vs LV end-systolic volume in radionuclide angiography, r=0.81, P0.01 at rest and r=0.75; P0.01 during exercise), but fractional shortening in echocardiography and ejection fraction in radionuclide angiography did not correlate (r=0.27, not significant (NS) at rest and r=0.34, NS during exercise). Thus echocardiography and radionuclide angiography describe LV dimensions at rest and during handgrip exercise in a similar fashion, documenting the concordance of these noninvasive methods to describe LV size in aortic incompetence at rest and during exercise.     

Detection of a false left ventricular aneurysm by first-pass radionuclide ventriculography

A false left ventricular aneurysm complicating an inferior myocardial infarction was successfully identified by computerized first-pass radionuclide ventriculography using a multicrystal gamma camera. The aneurysmal chamber exhibited paradoxical systolic expansion, a pattern of contraction confirmed by contrast cineangiography. Because of the propensity of false aneurysms to rupture, early noninvasive firm diagnosis is desirable and may be accomplished by first-pass radionuclide angiography.     

EANM/ESC guidelines for radionuclide imaging of cardiac function

Radionuclide imaging of cardiac function represents a number of well-validated techniques for accurate determination of right (RV) and left ventricular (LV) ejection fraction (EF) and LV volumes. These first European guidelines give recommendations for how and when to use first-pass and equilibrium radionuclide ventriculography, gated myocardial perfusion scintigraphy, gated PET, and studies with non-imaging devices for the evaluation of cardiac function. The items covered are presented in 11 sections: clinical indications, radiopharmaceuticals and dosimetry, study acquisition, RV EF, LV EF, LV volumes, LV regional function, LV diastolic function, reports and image display and reference values from the literature of RVEF, LVEF and LV volumes. If specific recommendations given cannot be based on evidence from original, scientific studies, referral is given to “prevailing or general consensus”. The guidelines are designed to assist in the practice of referral to, performance, interpretation and reporting of nuclear cardiology studies for the evaluation of cardiac performance.     

Temporal Fourier analysis applied to equilibrium radionuclide cineangiography importance in the study of global and regional left ventricular wall motion

Regional and global left ventricular wall motion was assessed in 120 patients using radionuclide cineangiography (RCA) and contrast angiography. Functional imaging procedures based on a temporal Fourier analysis of dynamic image sequences were applied to the study of cardiac contractility. Two images were constructed by taking the phase and amplitude values of the first harmonic in the Fourier transform for each pixel. These two images aided in determining the perimeter of the left ventricle to calculate the global ejection fraction. Regional left ventricular wall motion was studied by analyzing the phase value and by examining the distribution histogram of these values. The accuracy of global ejection fraction calculation was improved by the Fourier technique. This technique increased the sensitivity of RCA for determining segmental abnormalities especially in the left anterior oblique view (LAO).     

Thick maximum intensity projections for the assessment of left ventricular function with 64-slice computed tomography

OBJECTIVE: The objective of this study was to assess the accuracy of thick maximum intensity projections (MIP) from computed tomography (CT) data sets mimicking projection images from biplane ventriculography for evaluation of left ventricular (LV) parameters. MATERIALS AND METHODS: Fifty-eight patients underwent 64-slice CT. Multiphase images were reconstructed in 10% steps of the RR interval. MIP images (70-mm thickness) of the contrast-enhanced LV in fixed 30 degrees right anterior oblique (RAO)/60 degrees left anterior oblique (LAO) and in adapted short-/long-axis planes were reconstructed. LV parameters were calculated using the area-length method formula. Three-dimensional assessment with semiautomated software served as reference standard. RESULTS: Use of thick MIP reconstructions had a high intermethod reliability (86-94%) compared with the 3-dimensional approach. Smaller measurement errors were found for thick MIP reconstructions in adapted short-/long-axis planes. A significant projection error (3.0%, P < 0.001) of thick MIP reconstructions was found using fixed 30 degrees RAO/60 degrees LAO compared with adapted short-/long-axis reconstructions. CONCLUSION: Thick MIP reconstructions with adapted short-/long-axis planes allow an accurate assessment of LV parameters compared with the established 3-dimensional method.     

The radionuclide ejection fraction: a comparison of three radionuclide techniques with contrast angiography

Left-ventricular ejection fraction (EF) can be measured by several radionuclide methods. The EFs determined by three such methods (first-transit time-activity, equilibrium blood-pool time-activity, and equilibrium blood-pool area-length) were compared in 30 patients with EFs measured by area-length analysis of x-ray contrast angiograms. Both time-activity methods (first-transit and blood-pool) yielded EFs that correlated well with x-ray contrast EFs (r=0.86 and 0.84, respectively). Area-length analysis of blood-pool images yielded EFs that agreed less well with x-ray contrast EFs (r=0.73 in the RAO view, 0.70 in the LAO view). We conclude that first-transit and blood-pool techniques are equally accurate methods for determining EF when the time-activity method of analysis is employed.     

Comparison between vertical parallel hole collimator and 30 degrees rotating slant hole collimator for assessing global and regional left ventricular function by radionuclide angiography

Left ventricular ejection fraction (LVEF) and regional wall motion abnormalities were determined in 40 patients (30 with coronary artery disease and 10 with valvular heart disease) using equilibrium radionuclide angiography. Scintigraphic acquisitions were collected in random order with 2 different collimators as follows: in anterior face (AF), left anterior oblique (25 degrees-45 degrees LAO) and 70 degrees LAO, with a vertical parallel hole collimator (VTC), and in 25 degrees-45 degrees LAO and 65 degrees-80 degrees LAO with a 30 degrees rotating slant hole collimator (RSHC), with the slant of the collimator directed towards the cardiac apex in both projections. Results were compared to contrast ventriculography (CV) performed in the 30 degrees right anterior view (3 segments: anterior, apical, inferior) and in a 60 degrees left anterior oblique view (3 segments: septal, apical and lateral). Radionuclide LVEF in both series was closely correlated with contrast ventriculographic LVEF (r = 0.89, VTC vs CV and r = 0.87, RSHC vs CV, respectively). Regional wall motion analysis was only performed among the 30 patients suffering from coronary heart disease. Eight contrast angiographic studies were normal and 22 abnormal. Global sensitivity and specificity were 100% and 63% with the VTC (3 false positives) and 91% and 87% with the 30 degrees RSHC (2 false negatives and 1 false positive, P = ns). Agreement for the localisation of the regional wall motion abnormalities between CV and radionuclide angiography was 70.6% with the VTC and 71.2% with the RSHC (P = ns).(ABSTRACT TRUNCATED AT 250 WORDS)     

Combined evaluation of first-pass radionuclide angiography and equilibrium radionuclide ventriculography in the diagnosis of coronary artery disease. I. Results at rest

The results of 203 patients who underwent first-pass radionuclide angiography (FP), as well as quantitative equilibrium radionuclide ventriculography (qERNV), were stored in a data base system and evaluated statistically. In patients with coronary artery disease (CAD) without previous myocardial infarction (MI), evaluation of global and regional ejection fraction (gEF, rEF) at rest revealed a poor sensitivity of 64% (Rest-qERNV) and 69% (Rest-FP), respectively. In patients with a history of one previous MI, the sensitivity of both methods was equivalent: FP 87% and qERNV 84%. In patients with several MIs, sensitivity was higher than 90%. Concerning localization of MI, remarkable differences between FP and qERNV were found. In posterior wall infarction, the FP sensitivity was 87% and qERNV only 67%, whereas in anterior wall infarction, the results were similar for both methods: 93% (FP) and 96% (qERNV), respectively. Since 30 degrees RAO camera position achieves the best visualization of the anterior and posterior wall, FP is superior to qERNV in the evaluation of posterior wall asynergies. In addition, qERNV often fails to discriminate anterior and posterior wall motion abnormalities.     

Clinical validation of fully-automated contour detection for gated radionuclide ventriculography with a slant-hole collimator

A new fully-automated method for processing gated blood-pool images is presented and its clinical validity and performance for images with various noise levels are investigated using data obtained from a slant-hole collimator. The optimal preprocessing conditions are evaluated for the images with various noise levels to obtain the accurate ejection fraction, end-diastolic and end-systolic counts. This new method has successfully detected left ventricular contour in 92% of the 61 patients. The left ventricular ejection fraction obtained by the method related closely to that of contrast ventriculography (correlation coefficient r=0.90). The end-diastolic volume also had a good correlation with contrast ventriculography (r=0.90).     

Right ventricular function in healed myocardial infarction in man. A cineangiographic assessment

To evaluate the frequency of right ventricular dysfunction following recovery from myocardial infarction (MI) and the relationship of segmental right ventricular (RV) wall motion abnormalities to left ventricular (LV) function or location of coronary arterial stenosis, biplane right and left ventricular cineangiograms were obtained in 100 consecutive patients (4 +/- 3 months post MI). Thirty (group A) had anterior MI and significant stenosis or obstruction of left anterior descending artery (LAD). The remaining 70 patients had inferior MI. They were divided into three groups according to the site of the main coronary stenosis or obstruction and corresponding LV akinesia: right coronary artery (RCA) proximal to the acute marginal artery (RMA), (group B: 32 patients), RCA distal to the RMA (group C: 18 patients), left circumflex artery (LCF), (group D: 18 patients). RV and LV end-diastolic volume index (EDV), end-systolic volume index (ESV), stroke volume (SV) and ejection fraction (EF) have been determined. RV segmental wall motion was assessed in RAO and LAO projection by determining the percentage of systolic shortening (+ delta R) along 11 hemiaxes. Mean axial shortening (delta R) of the RV inferior and free walls were considered. When compared with that in 10 normal subjects, RV end-diastolic volume (RVEDV), RV end-systolic volume (RVESV) were increased and RV ejection fraction (RVEF) was lower in patients with anterior or inferior MI. Inferior delta R exhibited comparable sequential changes in the three groups of inferior MI and similar LVEF alteration.(ABSTRACT TRUNCATED AT 250 WORDS)