JIGSAW: Joint Inhomogeneity Estimation via Global Segment Assembly for Water-Fat Separation

نویسندگان

  • Wenmiao Lu
  • Yi Lu
چکیده

Water-fat separation in magnetic resonance imaging (MRI) is of great clinical importance, and the key to uniform water-fat separation lies in field map estimation. This work deals with three-point field map estimation, in which water and fat are modelled as two single-peak spectral lines, and field inhomogeneities shift the spectrum by an unknown amount. Due to the simplified spectrum modelling, there exists inherent ambiguity in forming field maps from multiple locally feasible field map values at each pixel. To resolve such ambiguity, spatial smoothness of field maps has been incorporated as a constraint of an optimization problem. However, there are two issues: the optimization problem is computationally intractable and even when it is solved exactly, it does not always separate water and fat images. Hence, robust field map estimation remains challenging in many clinically important imaging scenarios. This paper proposes a novel field map estimation technique called JIGSAW. It extends a loopy belief propagation (BP) algorithm to obtain an approximate solution to the optimization problem. The solution produces locally smooth segments and avoids error propagation associated with greedy methods. The locally smooth segments are then assembled into a globally consistent field map by exploiting the periodicity of the feasible field map values. In vivo results demonstrate that JIGSAW outperforms existing techniques and produces correct water-fat separation in challenging imaging scenarios.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Joint estimation of water/fat images and field inhomogeneity map.

Water/fat separation in the presence of B 0 field inhomogeneity is a problem of considerable practical importance in MRI. This article describes two complementary methods for estimating the water/fat images and the field inhomogeneity map from Dixon-type acquisitions. One is based on variable projection (VARPRO) and the other on linear prediction (LP). The VARPRO method is very robust and can b...

متن کامل

Accelerated water-fat imaging using restricted subspace field map estimation and compressed sensing.

Water-fat separation techniques play an important role in a variety of clinical and research applications. In particular, multiecho separation methods remain a topic of great interest due to their ability to resolve water and fat images in the presence of B(0)-field inhomogeneity. However, these methods are inherently slow as they require multiple measurements. An accelerated technique with red...

متن کامل

Hierarchical IDEAL – robust water-fat separation at high field by multiresolution field map estimation

Introduction In recent years, IDEAL (iterative decomposition of water and fat with echo asymmetry and least-squares estimation) [1] has gained considerable popularity as a practical method for acquiring high-quality fat and water images. At the core of IDEAL is a field-map estimation process, which is needed to properly assign signal components to the water and fat images. IDEAL holds particula...

متن کامل

A joint estimation method for two-point water/fat imaging with regularized field map

INTRODUCTION A recently developed joint estimation method for water/fat separation, based on a penalized maximum likelihood (PML) formulation and graph cuts optimization, is able to perform robustly in the presence of large B0 field inhomogeneities [1]. This method requires the acquisition of at least three images with different TE shifts, because the water and fat components of the signal are ...

متن کامل

Estimation of spinal loads using a detailed finite element model of the L4-L5 lumbar segment derived by medical imaging kinematics; a feasibility study

Introduction: Low back pain is the most prevalent orthopedic disorder and the first main cause of poor working functionality in developed as wells as many developing countries. In Absence of noninvasive in vivo measurement approaches, biomechanical models are used to estimate mechanical loads on human joints during physical activities. To estimate joint loads via musculoskelet...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • IEEE transactions on medical imaging

دوره 30 7  شماره 

صفحات  -

تاریخ انتشار 2011