Validation of Gated Blood-Pool SPECT Regional Left Ventricular Function Measurements

Abstract

Blood-pool (BP)-gated SPECT should be able to detect regional left ventricular (LV) dysfunction, as the modality is fully 3-dimensional and capable of resolving all cardiac chambers. This study investigates the hypothesis that LV segments that have abnormal regional wall motion (WM) on a cardiac MRI scan also have abnormal BP regional ejection fraction (EF) as computed by fully automated quantitation (AQ) of BP data. Methods: A total of 34 patients evaluated for coronary artery disease who underwent visual assessment of WM by review of BP cines and cardiac MRI evaluations were included in this retrospective investigation. Cardiac MRI values for these patients were compared with an institutional database of cardiac MRI values for an age-matched cohort of 10 healthy volunteers. An AQ algorithm segmented the LV BPs on the BP tomograms and subdivided volumes into 17 subregions. Count-versus-time curves were fit to third-order Fourier series for each LV subvolume to compute regional EFs. For cardiac MRI data, endocardial and epicardial drawings were performed manually for 60°sam-ples of 11-13 short-axis tomograms spanning the entire heart, from which regional WM values were computed and rebinned into 17 conventional LV segments. Results: Global EF ranged from 12% to 75% on AQ and from 14% to 75% on cardiac MRI (Pearson correlation coefficient 5 0.95, P , 0.0001). Differences were not significant between BP AQ and cardiac MRI in identifying the 12 patients with a global EF less than 35% (McNemar difference, 3%; P 5 1.0) and the 19 patients with an EF less than 50% (difference, 3%; P 5 1.0). BP AQ was more accurate than was visual assessment for identifying LV segments with abnormal cardiac MRI WM (receiver-operating-characteristic areas, 88% vs. 80%, P , 0.0001) and was more accurate for the left circumflex than for the left anterior descending coronary artery territories (95% vs. 86%, P 5 0.01). Differences were not significant between BP AQ and cardiac MRI WM for discriminating normal from abnormal LV segments (McNemar difference, 3.2%; P 5 0.14). Conclusion: AQ BP-gated SPECT assessment of regional and global LV WM agrees with independent cardiac MRI calculations and is superior to visual analysis for detecting regional WM abnormalities.

Comparison between 99mTc-sestamibi gated myocardial perfusion SPECT and echocardiography in assessment of left ventricular volumes and ejection fraction — effect of perfusion defect and small heart

“…On the other hand, in the presence of perfusion defect, in higher SRS scores and in patients with larger ventricle (ESV ≥ 25 ml), no remarkable difference was noticed between two modalities. Similarly to our study, previous studies that compared GSPECT and ECHO, reported good agreement between LVEF, EDV and ESV values [2,9,[12][13][14][15][16][17]. Zanger et al [18] reported a good agreement between ECHO and GSPECT for determination of LVEF and LVVs.…”

Left Ventricular Ejection Fraction Assessment by Tl‐201 Gated SPECT: A Comparison With Echocardiography

“…21 A study similar to ours, comparing LVEF by Tc-99 m-sestamibi and the 2-DE method of disc measurement in 201 community-based patients, obtained almost identical results. 22 One may argue that visual eyeball estimation of LVEF by 2-DE is inaccurate, and that direct measurements using published techniques such as the area-length method or the biplane method of discs (modified Simpson's rule) 13 are more reliable. However, eyeball estimation competency and its validity, especially when performed by experienced echocardiologists, are well established.…”

The expanding role of left ventricular functional assessment using gated myocardial perfusion SPECT: the supporting actor is stealing the scene

“…Subsequent studies compared the QGS results with other reference techniques, such as equilibrium radionuclide angiocardiography (ERNA), echocardiography, contrast ventriculography and magnetic resonance imaging [16, 19-21, 23, 26-36, 55]. The Emory Cardiac Toolbox (ECTb, Emory University, Atlanta, GA) has also been extensively validated by comparison with first-pass radionuclide ventriculography, ERNA, echocardiography and magnetic resonance imaging [23,25,30,34,55]. Furthermore, comparative studies with ERNA and magnetic resonance imaging have confirmed the reliability of 4D-MSPECT (University of Michigan Medical Center, Ann Arbor, MI) [32,34,55,56].…”