Evaluation of PET quantitation accuracy among multiple discovery IQ PET/CT systems via NEMA image quality test oleh Delphine Vallot, Elena De Ponti, Sabrina Morzenti, Anna Gramek, Anna Pieczonka, Gabriel Reynés Llompart, Jakub Siennicki, Paul Deak, Chiranjib Dutta, Jorge Uribe, Olivier Caselles