Left ventricular function assessment using 123I/99mTc dual-isotope acquisition with two semi-conductor cadmium–zinc–telluride (CZT) cameras: a gated cardiac phantom study

Abstract

BackgroundThe impact of increased energy resolution of cadmium–zinc–telluride (CZT) cameras on the assessment of left ventricular function under dual-isotope conditions (99mTc and 123I) remains unknown.The Amsterdam-gated dynamic cardiac phantom (AGATE, Vanderwilt techniques, Boxtel, The Netherlands) was successively filled with a solution of 123I alone, 99mTc alone, and a mixture of 123I and 99mTc. A total of 12 datasets was acquired with each commercially available CZT camera (DNM 530c, GE Healthcare and DSPECT, Biosensors International) using both energy windows (99mTc or 123I) with ejection fraction set to 33, 45, and 60 %. End-diastolic (EDV) and end-systolic (ESV) volumes, ejection fraction (LVEF), and regional wall motion and thickening (17-segment model) were assessed using Cedars-Sinai QGS Software. Concordance between single- and dual-isotope acquisitions was tested using Lin’s concordance correlation coefficient (CCC) and Bland–Altman plots.ResultsThere was no significant difference between single- or simultaneous dual-isotope acquisition (123I and 99mTc) for EDV, ESV, LVEF, or segmental wall motion and thickening. Myocardial volumes using single- (123I, 99mTc) and dual-isotope (reconstructed using both 123I and 99mTc energy windows) acquisitions were, respectively, the following: EDV (mL) 88 ± 27 vs. 89 ± 27 vs. 92 ± 29 vs. 90 ± 26 for DNM 530c (p = NS) and 82 ± 20 vs. 83 ± 22 vs. 79 ± 19 vs. 77 ± 20 for DSPECT (p = NS); ESV (mL) 40 ± 1 vs. 41 ± 2 vs. 41 ± 2 vs. 42 ± 1 for DNM 530c (p = NS) and 37 ± 5 vs. 37 ± 1 vs. 35 ± 3 vs. 34 ± 2 for DSPECT (p = NS); LVEF (%) 52 ± 14 vs. 51 ± 13 vs. 53 ± 13 vs. 51 ± 13 for DNM 530c (p = NS) and 52 ± 16 vs. 54 ± 13 vs. 54 ± 14 vs. 54 ± 13 for DSPECT (p = NS); regional motion (mm) 6.72 ± 2.82 vs. 6.58 ± 2.52 vs. 6.86 ± 2.99 vs. 6.59 ± 2.76 for DNM 530c (p = NS) and 6.79 ± 3.17 vs. 6.81 ± 2.75 vs. 6.71 ± 2.50 vs. 6.62 ± 2.74 for DSPECT (p = NS). The type of camera significantly impacted only on ESV (p < 0.001).ConclusionsThe new CZT cameras yielded similar results for the assessment of LVEF and regional motion using different energy windows (123I or 99mTc) and acquisition types (single vs. dual). With simultaneous dual-isotope acquisitions, the presence of 123I did not impact on LVEF assessment within the 99mTc energy window for either CZT camera.

Determination of the Heart-to-Mediastinum Ratio of 123I-MIBG Uptake Using Dual-Isotope (123I-MIBG/99mTc-Tetrofosmin) Multipinhole Cadmium-Zinc-Telluride SPECT in Patients with Heart Failure

“…As previously reported (22), the presence of 123 I did not have an impact on LVEF assessment within the 99m Tc energy window in the dual-isotope condition for DNM-530c. Accordingly, the LVEF was assessed using Quantitative Gated SPECT software (Cedars-Sinai Medical Center).…”

“…Previous studies using phantom data acquired separately for 99m Tc and 123 I showed that 99m Tc cross-talk into the 123 I window was negligible when a simultaneous CZT SPECT acquisition was performed (21,22). To ensure that different 99m Tc/ 123 I ratios did not have an impact on energy resolution, we acquired a set of energy spectra (single 123 I, single 99m Tc, and dual 123 I/ 99m Tc) using linear sources with three 99m Tc/ 123 I ratios (0.5:1, 1:1, and 5:1) and a constant activity of 123 I (24 MBq) ( Fig.…”

Single Photon Emission Computed Tomography (SPECT) Myocardial Perfusion Imaging Guidelines: Instrumentation, Acquisition, Processing, and Interpretation

“…Furthermore, the greater energy resolution of the CZT camera may allow simultaneous dual isotope imaging of 99m Tc-based and 201 Tl perfusion tracers 53 or molecular imaging agents, such as 123 I-b-methyl-iodophenyl-pentadecanoic acid (BMIPP). 54 It is important to remember that the same energy windows used in performing patient studies should be used for routine, daily QC. Some of the scanners acquire dual energy windows (120 keV for 99m Tc) to allow for scatter correction.…”

One Year of Nuclear Cardiology in France

“…RM correction had an impact on qualitative and Annals of Nuclear Cardiology Vol. showed that global and segmental LV function assessment was also feasible using 99m Tc/ 123 I dual-isotope acquisitions (9). A dynamic cardiac phantom was imaged using two commercially available CZT cameras (DNM 530c, GE Healthcare, and D-SPECT, Spectrum Dynamics) and scatter, cross-talk, and tailing effect corrections were applied when available.…”