RT Journal Article SR Electronic T1 Preliminary Study on the Diagnostic Value of 11C-PIB PET/MR in cardiac amyloidosis JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 103 OP 103 VO 60 IS supplement 1 A1 Bi, Xiao A1 Liu, Jiajin A1 Dong, Wei A1 Guan, Zhiwei A1 Zhang, Xiaojun A1 An, Jing A1 Xu, Baixuan A1 Tian, Jiahe YR 2019 UL http://jnm.snmjournals.org/content/60/supplement_1/103.abstract AB 103Introduction: Cardiac amyloidosis (CA) is a group of diseases caused by extracellular accumulation of insoluble misfolded fibrillar proteins with featuring clinical manifestations of restrictive cardiomyopathy. To demonstrate amyloid fibril deposition by Congo-red staining in myocardial biopsy sample is still gold standard for precise diagnosis of CA. However, endomyocardial biopsy is relatively invasive and can not be performed routinely. 11C-Pittsburgh B (PiB) as a derivative of thioflavin-T, has been successfully used for Alzheimer’s disease imaging as it could combine with the β-amyloid protein deposit in brain. This study preliminarily investigated the value of 11C-PIB PET/MR in the diagnosis of CA. Methods: 12 patients suffering from heart failure and suspected of CA based on echocardiographic findings were included in this prospective study. All patients completed cardiac 11C-PIB PET/MR (Biograph mMR, Siemens Healthcare, Erlangen, Germany) and non-cardiac biopsywithin one week. MRI sequences included cine, late gadolinium enhancement (LGE) and native T1 mapping. 6 normal volunteers were enrolled in the cardiac 11C-PIB PET/MR as a contral group. PET scan was performed 40 minutes after 11C-PIB administration for 20 minutes. LVEF, IVSD, LVPW, Native T1 value and maximum uptake of myocardial tissue-to-blood background ratio (TBRmax)were measured. The diagnostic efficacy of TBRmax was analyzed by ROC curve, and nonparametric Mann-Whitney U test was used to compare the measured values between the CA patients and the normal controls. Results: Among 12 patients, 8 patients were clinically diagnosed as CA and the other 4 cases as dilated cardiomyopathy, valvular heart disease, hypertensive heart disease, and hypertrophic heart disease. All the CA patients had diffused transmural LGE pattern different from those of DCM, VHD, HHD and HCM. When the cut-off value was 0.975, the diagnostic sensitivity and specificity of TBRmax were 75% and 100%, respectively. There was significant difference between the CA patients and normal controls in terms of LVEF(44.43±12.69 VS 65.15±1.86, P=0.005), IVSD(13.38±3.21 VS 8.32±0.53, P=0.001), LVPW(11.41±3.12 VS 7.62±0.81, P=0.043), Native T1 value(1550.5±31.29 VS 1233.51±46.73, P=0.001)and TBRmax(2.44±1.90 VS 0.85±0.06, P=0.001). Conclusions: 11C-PIB PET/MR may be valuable in the noninvasive diagnosis of CA. Further study with a larger cohort of patients would be needed to confirm it.