Groupwise image registration describes the problem of simultaneously aligning a series more than two images through individual spatial deformations and it is common task in processing medical sequences. Variational methods with data fidelity terms based on robust PCA (RPCA) have proven successful accounting for structural changes intensity stemming, e.g., from uptake contrast agent functional i...

Deformable medical image registration plays a vital role in applications, such as placing different temporal images at the same time point or modality into coordinate system. Various strategies have been developed to satisfy increasing needs of deformable registration. One popular method is estimating displacement field by computing optical flow between two images. The motion (flow field) compu...

In this paper, we present a new approach to tackle simultaneously linear and deformable registration between two images. Our combined formulation avoids the bias created when linear registration is performed independently before a deformable registration. Our registration problem is formulated as a discrete Markov Random Field and a higher order objective function. Usually, a grid is superimpos...

Deformable (non-rigid) registration is an essential tool in both adaptive radiation therapy and image-guided radiation therapy to account for soft-tissue changes during the course of treatment. The evaluation method most commonly used to assess the accuracy of deformable image registration is qualitative human evaluation. Here,we propose a method for systematically measuring the accuracy of an ...

PURPOSE Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) shows high sensitivity in detecting breast cancer. However, its performance could be affected by patient motion during the imaging. To overcome this problem, it is necessary to correct patient motion by deformable registration, before using the DCE-MRI to detect breast cancer. However, deformable registration of DCE-MR image...

The purpose of this study is to evaluate the performance variations in commercial deformable image registration (DIR) tools for adaptive radiation therapy and further to interpret the differences using clinically available terms. Three clinical examples (prostate, head and neck (HN), and cranial spinal irradiation (CSI) with L-spine boost) were evaluated in this study. Firstly, computerized def...

PURPOSE The aim of this study was to evaluate the appropriateness of using computed tomography (CT) to cone-beam CT (CBCT) deformable image registration (DIR) for the application of calculating the "dose of the day" received by a head and neck patient. METHODS NiftyReg is an open-source registration package implemented in our institution. The affine registration uses a Block Matching-based ap...

The purpose of this study was to propose and evaluate a method of creating a synthetic CT (S-CT) from MRI simulation for dose calculation and daily CBCT localization. A pair of MR and CT images was obtained in the same day from each of 10 prostate patients. The pair of MR and CT images was preregistered using the deformable image registration (DIR). Using the corresponding displacement vector f...