TY - GEN

T1 - A maximum-likelihood approach for ADC estimation of lesions in visceral organs

AU - Jha, Abhinav K.

AU - Rodríguez, Jeffrey J.

PY - 2012

Y1 - 2012

N2 - Accurate estimation of the apparent diffusion coefficient (ADC) of lesions in diffusion-weighted magnetic resonance imaging (DWMRI) is important to predict and monitor anticancer therapy response. The task of ADC estimation of lesions is complicated due to noise in the image, different variances in signal strengths at different b values and other random phenomena. In organs that have visceral motion, due to motion across scans, estimating the ADC becomes even more complex. To get rid of inaccuracies due to motion, only a single ADC value of the lesion is estimated, conventionally using a linear-regression (LR) approach. The LR approach is based on an inaccurate noise model and also suffers from other deficiencies. In this paper, we propose an easy-to-implement and computationally-fast maximum-likelihood (ML) method to estimate the ADC value of heterogeneous lesions in visceral organs. The proposed method takes into account the Rician distribution of noise in DWMRI. In the process, we also derive the statistical model for the measured mean signal intensity in DWMRI. We show using Monte-Carlo simulations that that the proposed method is more accurate than the LR method.

AB - Accurate estimation of the apparent diffusion coefficient (ADC) of lesions in diffusion-weighted magnetic resonance imaging (DWMRI) is important to predict and monitor anticancer therapy response. The task of ADC estimation of lesions is complicated due to noise in the image, different variances in signal strengths at different b values and other random phenomena. In organs that have visceral motion, due to motion across scans, estimating the ADC becomes even more complex. To get rid of inaccuracies due to motion, only a single ADC value of the lesion is estimated, conventionally using a linear-regression (LR) approach. The LR approach is based on an inaccurate noise model and also suffers from other deficiencies. In this paper, we propose an easy-to-implement and computationally-fast maximum-likelihood (ML) method to estimate the ADC value of heterogeneous lesions in visceral organs. The proposed method takes into account the Rician distribution of noise in DWMRI. In the process, we also derive the statistical model for the measured mean signal intensity in DWMRI. We show using Monte-Carlo simulations that that the proposed method is more accurate than the LR method.

KW - ADC estimation

KW - Maximum-likelihood method

KW - Mean of Rician distributed random variables

UR - http://www.scopus.com/inward/record.url?scp=84862750200&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84862750200&partnerID=8YFLogxK

U2 - 10.1109/SSIAI.2012.6202443

DO - 10.1109/SSIAI.2012.6202443

M3 - Conference contribution

AN - SCOPUS:84862750200

SN - 9781467318303

T3 - Proceedings of the IEEE Southwest Symposium on Image Analysis and Interpretation

SP - 21

EP - 24

BT - 2012 IEEE Southwest Symposium on Image Analysis and Interpretation, SSIAI 2012, Proceedings

T2 - 2012 IEEE Southwest Symposium on Image Analysis and Interpretation, SSIAI 2012

Y2 - 22 April 2012 through 24 April 2012

ER -