[Magnetic Resonance Imaging Tissue Feature Tracking for Cardiac Amyloidosis].

OBJECTIVE: To detect cardiac amyloidosis (CA) using cardiac magnetic resonance feature tracking(CMR-FT). METHODS: Forty-three CA patients and 24 healthy volunteers underwent steady-state free precession cine sequence on 3.0T MRI after injection of Magnevist. Software cvi 42 was used for analyzing the left ventricular function including left ventricular mass (diastole) (LVMD), left ventricular mass (systole) (LVMS), left ventricle end-diastolic volume (LVEDV), left ventricle end-systolic volume (LVESV), left ventricle stroke volume (LVSV), and left ventricular ejection fraction (LVEF), as well as myocardial strains including 3D global longitudinal strain (GLS), global circumferential strain (GCS), and global radial strain (GRS), and 2D endocardial and epicardial longitudinal strain, circumferential strain, and radial strain (ENDO-LS, EPI-LS, ENDO-CS, EPI-CS, ENDO-RS, and EPI-RS). The global and layer-specific strains were compared between the CA patients with LVEF >50%, the CA patients with LVEF ≤50%, and the healthy controls. RESULTS: For the left ventricular function, the CA patients had greater myocardial mass than the healthy controls (P < 0.05); the CA patients with LVEF ≤50% had greater LVESV and lower LVSV than those with LVEF >50% (P < 0.05). For the global strains, significant differences also appeared in GLS and GCS among the three groups (all P < 0.05). The CA patients had lower GRS than the healthy controls (P < 0.05), while no significant difference was found in GRS between the CA patients with LVEF >50% and those with LVEF ≤50% (P>0.05). For the layer-specific strains, significant differences in ENDO-LS, EPI-LS, ENDO-CS, EPI-CS, ENDO-RS, and EPI-RS were found among the three groups (all P < 0.05). There were significant correlations between GLS and LVEF (r=-0.404, P=0.016), and between GCS and LVEF (r=-0.602, P < 0.001) in the CA patients. CONCLUSION: CMR-FT can assess not only global strains but also layer-specific strains for the myocardial function of CA patients.

[Establishment of Bone Metastasis Model of Prostate Cancer in Mice with Monitoring of 18F-NaF PET-CT].

OBJECTIVES: To establish a mouse model bearing human prostate cancer xenograft with bone metastasis by the monitoring with X-Ray, Micro CT, and ¹8F-NaF PET/CT. METHODS: Sixteen male Balb/c nude mice were allocated into control (6 mice) and experimental group (10 mice). In experimental group, the mice were subjected to percutaneous injection of 2×105PC-3 cells into tibial plateau, bone defects were assessed after 21 d by X-ray, Micro-CT and ¹8F-NaF PET/CT, and bone damages were evaluated by HE staining. In control group, equal volume of saline was injected into the mice. RESULTS: At 21 d post modeling, the significant radioactive ¹8F--NaF signals were found in the tibial intramedullary cavity of all 10 mice in experimental group. The ROI value evaluation showed that SUVmaxin control group was 0.62±0.14, but SUVmaxin tumor group was 2.10±0.13, which indicated abnormal bone metabolism. The serum alkaline phosphate level and HE staining results also confirmed that tumor mediated bone destruction and osteogenesis. However, X-ray and Micro-CT did not indicate precise diagnostic bone defect. CONCLUSION: Bone metastasis model of prostate PC-3 cancer cells were successfully established by intratibial injection. ¹8F-NaF PET/CT could detect tumor invasion and bone osteogenesis in the early stage of modeling.