Cardiac Magnetic Resonance–Derived Extracellular Volume Mapping for the Quantification of Hepatic and Splenic Amyloid

Background: Systemic amyloidosis is characterized by amyloid deposition that can involve virtually any organ. Splenic and hepatic occurs in certain types, some patients but not others, may influence prognosis treatment. SAP (serum P component) scintigraphy uniquely able to identify quantify the liver spleen, thus informing clinical management, it only available 2 centers globally. The aims of this study were examine potential for extracellular volume (ECV) mapping performed during routine cardiac magnetic resonance to: (1) detect spleen (2) estimate load these sites using as reference standard. Methods: Five hundred thirty-three referred National Amyloidosis Centre, London, between 2015 2017 with suspected systemic who underwent T1 studied. Results: diagnostic performance ECV splenic was high both organs (liver: area under curve, −0.917 [95% CI, 0.880–0.954]; cutoff, 0.395; sensitivity, 90.7%; specificity, 77.7%; <0.001; spleen: −0.944 0.925–0.964]; 0.385; 93.6%; 87.5%; <0.001). There good correlation assessed (r=0.504, r=0.693, <0.001, respectively). interobserver agreement (ECV intraclass coefficient, 0.991 0.984–0.995]; 0.995 0.991–0.997]; <0.001) little bias across a wide range values. Conclusions: Our demonstrates measurements obtained scans measure magnitude infiltration providing important clues type offering noninvasive visceral burden help guide track