Codice  QDD 121 
Titolo  Estimation approaches for the Apparent Diffusion Coefficient in Ricedistributed MR signals 
Data  20120402 
Autore/i  Baraldo, S.; Ieva, F.; Mainardi, L.; Paganoni, A. M. 
Link  Download full text  Pubblicato  Book of extended proceedings from SCo 2011 conference 
Abstract  The Apparent Diffusion Coefficient (ADC) is often considered in the differential diagnosis of tumors, since the analysis of a field of ADCs on a particular region of the body allows to identify regional necrosis. This quantity can be estimated from magnitude signals obtained in diffusion
Magnetic Resonance (MR), but in some situations, like total body MRs, it is possible to repeat only few measurements on the same patient, thus providing a limited amount of data for the estimation of ADCs. In this work we consider a Rician distributed magnitude signal with an exponential
dependence on the socalled bvalue. Different pixelwise estimators for the ADC, both frequentist and Bayesian, are proposed and compared by a simulation study, focusing on issues caused by low signaltonoise ratios and small sample sizes. 
