Respiratory motion reduction with a dual gating approach in myocardial perfusion SPECT: Effect on left ventricular functional parameters.

BACKGROUND: Respiratory motion (RM) complicates the analysis of myocardial perfusion (MP) single-photon emission computed tomography (SPECT) images. The effects of RM on left ventricular (LV) functional variables have not been thoroughly investigated. METHODS AND RESULTS: Thoracic electrical bioimpedance and electrocardiographic signals were recorded from eighteen patients undergoing the rest phase of a 1-day stress/rest cardiac-gated MP-SPECT examination. The signals and list-mode emission data were retrospectively processed to yield standard cardiac- and dual-gated (respiratory and cardiac gating) image sets applying a novel algorithm. LV volume, MP, shape index (SI), wall motion (WM), wall thickening (WT), and phase analysis parameters were measured with Quantitative Perfusion SPECT/Quantitative Gated SPECT software (Cedars-Sinai Medical Center). Image quality was evaluated by three experienced physicians. Dual gating increased LV volume (77.1 ± 26.8 vs 79.8 ± 27.6 mL, P = .006) and decreased SI (0.57 ± 0.05 vs 0.56 ± 0.05, P = .036) and global WT (39.0 ± 11.8% vs 36.9 ± 9.4%, P = .034) compared to cardiac gating, but did not significantly alter perfusion, WM or phase analysis parameters or image quality (P > .05). CONCLUSIONS: RM reduction has an effect on LV volume, shape, and WT parameters. RM exerts no significant effect on phase analysis parameters.

Early familial dilated cardiomyopathy: identification with determination of disease state parameter from cine MR image data.

PURPOSE: To characterize early changes in cardiac anatomy and function for lamin A/C gene (LMNA) mutation carriers by using magnetic resonance (MR) imaging and to develop tools to analyze and visualize the findings. MATERIALS AND METHODS: The ethical review board of the institution approved the study, and informed written consent was obtained. The patient group consisted of 12 subjects, seven women (mean age, 36 years; age range, 18-54 years) and five men (mean age, 28 years; age range, 18-39 years) of Finnish origin, who were each heterozygotes with one LMNA mutation that may cause familial dilated cardiomyopathy (DCM). All the subjects were judged to be healthy with transthoracic echocardiography. The control group consisted of 14 healthy subjects, 11 women (mean age, 41 years; range, 23-54 years) and three men (mean age, 45 years; range, 34-57 years), of Finnish origin. Cine steady state free precession MR imaging was performed with a 1.5-T system. The volumes, wall thickness, and wall motion of both left ventricle (LV) and right ventricle were assessed. A method combining multiple MR image parameters was used to generate a global cardiac function index, the disease state parameter (DSP). A visual fingerprint was generated to assess the severity of familial DCM. RESULTS: The mean DSP of the patient group (0.69 +/- 0.15 [standard deviation]) was significantly higher than that of the control group (0.32 +/- 0.13) (P = .00002). One subject had an enlarged LV. CONCLUSION: Subclinical familial DCM was identified by determination of the DSP with MR imaging, and this method might be used to recognize familial DCM at an early stage.