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Deformable Image Registration

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https://www.readbyqxmd.com/read/29333123/evaluation-of-deformable-image-registration-dir-methods-for-dose-accumulation-in-nasopharyngeal-cancer-patients-during-radiotherapy
#1
Wannapha Nobnop, Imjai Chitapanarux, Hudsaleark Neamin, Somsak Wanwilairat, Vicharn Lorvidhaya, Taweap Sanghangthum
Introduction: Deformable image registration (DIR) is used to modify structures according to anatomical changes for observing the dosimetric effect. In this study, megavoltage computed tomography (MVCT) images were used to generate cumulative doses for nasopharyngeal cancer (NPC) patients by various DIR methods. The performance of the multiple DIR methods was analysed, and the impact of dose accumulation was assessed. Patients and methods: The study consisted of five NPC patients treated with a helical tomotherapy unit...
December 2017: Radiology and Oncology
https://www.readbyqxmd.com/read/29331575/validation-of-mri-to-trus-registration-for-high-dose-rate-prostate-brachytherapy
#2
Eric Poulin, Karim Boudam, Csaba Pinter, Samuel Kadoury, Andras Lasso, Gabor Fichtinger, Cynthia Ménard
PURPOSE: The objective of this study was to develop and validate an open-source module for MRI to transrectal ultrasound (TRUS) registration to support tumor-targeted prostate brachytherapy. METHODS AND MATERIALS: In this study, 15 patients with prostate cancer lesions visible on multiparametric MRI were selected for the validation. T2-weighted images with 1-mm isotropic voxel size and diffusion weighted images were acquired on a 1.5T Siemens imager. Three-dimensional (3D) TRUS images with 0...
January 10, 2018: Brachytherapy
https://www.readbyqxmd.com/read/29331573/deformable-image-registration-based-contour-propagation-yields-clinically-acceptable-plans-for-mri-based-cervical-cancer-brachytherapy-planning
#3
Christina Hunter Chapman, Daniel Polan, Karen Vineberg, Shruti Jolly, Katherine E Maturen, Kristy K Brock, Joann I Prisciandaro
PURPOSE: To study the dosimetric impact of deformable image registration-based contour propagation on MRI-based cervical cancer brachytherapy planning. METHODS AND MATERIALS: High-risk clinical target volume (HRCTV) and organ-at-risk (OAR) contours were delineated on MR images of 10 patients who underwent ring and tandem brachytherapy. A second set of contours were propagated using a commercially available deformable registration algorithm. "Manual-contour" and "propagated-contour" plans were optimized to achieve a maximum dose to the most minimally exposed 90% of the volume (D90) (%) of 6 Gy/fraction, respecting minimum dose to the most exposed 2cc of the volume (D2cc) OAR constraints of 5...
January 10, 2018: Brachytherapy
https://www.readbyqxmd.com/read/29324241/low-dimensional-representation-of-cardiac-motion-using-barycentric-subspaces-a-new-group-wise-paradigm-for-estimation-analysis-and-reconstruction
#4
Marc-Michel Rohé, Maxime Sermesant, Xavier Pennec
One major challenge when trying to build low-dimensional representation of the cardiac motion is its natural circular pattern during a cycle, therefore making the mean image a poor descriptor of the whole sequence. Therefore, traditional approaches for the analysis of the cardiac deformation use one specific frame of the sequence - the end-diastolic (ED) frame - as a reference to study the whole motion. Consequently, this methodology is biased by this empirical choice. Moreover, the ED image might be a poor reference when looking at large deformation for example at the end-systolic (ES) frame...
December 23, 2017: Medical Image Analysis
https://www.readbyqxmd.com/read/29306379/variation-assessment-of-deformable-registration-in-stereotactic-radiosurgery
#5
C-S Chang, R Shih, J-M Hwang, K-S Chuang
INTRODUCTION: The regular functions of CT-MRI registration include delineation of targets and organs-at-risk (OARs) in radiosurgery planning. The question of whether deformable image registration (DIR) could be applied to stereotactic radiosurgery (SRS) in its place remains a subject of debate. METHODS: This study collected data regarding 16 patients who had undergone single-fraction SRS treatment. All lesions were located close to the brainstem. CT and MRI two image sets were registered by both rigid image registration (RIR) and DIR algorithms...
February 2018: Radiography
https://www.readbyqxmd.com/read/29305790/patient-specific-estimation-of-detailed-cochlear-shape-from-clinical-ct-images
#6
H Martin Kjer, Jens Fagertun, Wilhelm Wimmer, Nicolas Gerber, Sergio Vera, Livia Barazzetti, Nerea Mangado, Mario Ceresa, Gemma Piella, Thomas Stark, Martin Stauber, Mauricio Reyes, Stefan Weber, Marco Caversaccio, Miguel Ángel González Ballester, Rasmus R Paulsen
PURPOSE: A personalized estimation of the cochlear shape can be used to create computational anatomical models to aid cochlear implant (CI) surgery and CI audio processor programming ultimately resulting in improved hearing restoration. The purpose of this work is to develop and test a method for estimation of the detailed patient-specific cochlear shape from CT images. METHODS: From a collection of temporal bone [Formula: see text]CT images, we build a cochlear statistical deformation model (SDM), which is a description of how a human cochlea deforms to represent the observed anatomical variability...
January 6, 2018: International Journal of Computer Assisted Radiology and Surgery
https://www.readbyqxmd.com/read/29300320/free-form-deformation-approach-for-registration-of-visible-and-infrared-facial-images-in-fever-screening
#7
Yedukondala Narendra Dwith Chenna, Pejhman Ghassemi, T Joshua Pfefer, Jon Casamento, Quanzeng Wang
Fever screening based on infrared (IR) thermographs (IRTs) is an approach that has been implemented during infectious disease pandemics, such as Ebola and Severe Acute Respiratory Syndrome. A recently published international standard indicates that regions medially adjacent to the inner canthi provide accurate estimates of core body temperature and are preferred sites for fever screening. Therefore, rapid, automated identification of the canthi regions within facial IR images may greatly facilitate rapid fever screening of asymptomatic travelers...
January 4, 2018: Sensors
https://www.readbyqxmd.com/read/29297939/technical-note-the-impact-of-deformable-image-registration-methods-on-dose-warping
#8
An Qin, Jian Liang, Xiao Han, Nicolette O'Connell, Di Yan
PURPOSE: To investigate the clinical-relevant discrepancy between doses warped by pure-image based deformable image registration (IM-DIR) and by biomechanical-model based DIR (BM-DIR) on intensity homogeneous organs. METHODS AND MATERIALS: Ten patients (5Head&Neck, 5Prostate) were included. A research DIR tool (ADMRIE_v1.12) was utilized for IM-DIR. After IM-DIR, BM-DIR was carried out for organs (parotids, bladder, and rectum) which often encompass sharp dose gradient...
January 3, 2018: Medical Physics
https://www.readbyqxmd.com/read/29297607/signal-enhancement-ratio-imaging-of-the-lung-parenchyma-with-ultra-fast-steady-state-free-precession-mri-at-1-5t
#9
Orso Pusterla, Gregor Sommer, Francesco Santini, Mark Wiese, Didier Lardinois, Michael Tamm, Jens Bremerich, Grzegorz Bauman, Oliver Bieri
BACKGROUND: Lung perfusion MRI after i.v. gadolinium (Gd) contrast administration is commonly based on spoiled gradient-echo acquisitions, such as volume-interpolated breath-hold examinations (VIBE), suffering from low signal-to-noise in the parenchyma. PURPOSE: To investigate the lung signal enhancement ratio (SER) with ultra-fast steady-state free precession (ufSSFP) after Gd-administration. STUDY TYPE: Retrospective. SUBJECTS: Ten subjects with healthy lungs; nine patients with pulmonary diseases (chronic obstructive pulmonary disease [COPD], lung cancer, pulmonary fibrosis, lung contusion)...
January 3, 2018: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/29290405/ct-ventilation-imaging-derived-from-breath-hold-ct-exhibits-good-regional-accuracy-with-galligas-pet
#10
Enid M Eslick, John Kipritidis, Denis Gradinscak, Mark J Stevens, Dale L Bailey, Benjamin Harris, Jeremy T Booth, Paul J Keall
BACKGROUND AND PURPOSE: CT ventilation imaging (CTVI) derived from four dimensional CT (4DCT) has shown only moderate spatial accuracy in humans due to 4DCT image artefacts. Here we assess the accuracy of an improved CTVI using high quality exhale/inhale breath-hold CT (BHCT). MATERIALS AND METHODS: Eighteen lung cancer patients underwent exhale/inhale BHCT, 4DCT and Galligas PET ventilation scans in a single imaging session. For each BHCT and 4DCT scan, we performed deformable image registration (DIR) between the inhale and exhale phase images to quantify ventilation using three published metrics: (i) breathing induced lung density change, CTVIDIR-HU (ii) breathing induced volume change CTVIDIR-Jac and (iii) the regional air-tissue product, CTVIHU Spatial accuracy was reported as the voxel-wise Spearman correlation r between CTVI and Galligas PET...
December 28, 2017: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
https://www.readbyqxmd.com/read/29290025/a-hybrid-optimization-strategy-for-registering-images-with-large-local-deformations-and-intensity-variations
#11
Zhang Li, Lucas J van Vliet, Jaap Stoker, Frans M Vos
PURPOSE: To develop a method for intra-patient registration of pre- and post-contrast abdominal MR images with large local deformations and large intensity variations. METHOD: A hybrid method is proposed to deal with this problem. It consists of two coupled techniques: (1) descriptor matching (DM) at the original resolution using a discrete optimization strategy to avoid getting trapped in a local minimum; (2) continuous optimization to refine the registration outcome based on autocorrelation of local image structure (ALOST)...
December 30, 2017: International Journal of Computer Assisted Radiology and Surgery
https://www.readbyqxmd.com/read/29285519/characterization-and-correction-of-intraoperative-soft-tissue-deformation-in-image-guided-laparoscopic-liver-surgery
#12
Jon S Heiselman, Logan W Clements, Jarrod A Collins, Jared A Weis, Amber L Simpson, Sunil K Geevarghese, T Peter Kingham, William R Jarnagin, Michael I Miga
Laparoscopic liver surgery is challenging to perform due to a compromised ability of the surgeon to localize subsurface anatomy in the constrained environment. While image guidance has the potential to address this barrier, intraoperative factors, such as insufflation and variable degrees of organ mobilization from supporting ligaments, may generate substantial deformation. The severity of laparoscopic deformation in humans has not been characterized, and current laparoscopic correction methods do not account for the mechanics of how intraoperative deformation is applied to the liver...
April 2018: Journal of Medical Imaging
https://www.readbyqxmd.com/read/29283466/improved-segmental-myocardial-strain-reproducibility-using-deformable-registration-algorithms-compared-with-feature-tracking-cardiac-mri-and-speckle-tracking-echocardiography
#13
Jie Wang, Weihao Li, Jiayu Sun, Hong Liu, Yu Kang, Dan Yang, Liuyu Yu, Andreas Greiser, Xiaoyue Zhou, Yuchi Han, Yucheng Chen
BACKGROUND: Segmental myocardial strain using feature tracking (FT) cardiac MRI is not acceptable due to poor reproducibility. PURPOSE: To assess the reproducibility of left ventricle (LV) segmental myocardial strain measured by deformation registration algorithm (DRA). STUDY TYPE: Prospective clinical trial. SUBJECTS: Sixteen healthy volunteers and 28 hypertrophic cardiomyopathy (HCM) patients. FIELD STRENGTH/SEQUENCE: Retrospective ECG gating cardiac MRI imaging was performed at 3...
December 28, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/29278582/computer-assisted-surgery-virtual-and-augmented-reality-displays-for-navigation-during-urological-interventions
#14
Matthias N van Oosterom, Henk G van der Poel, Nassir Navab, Cornelis J H van de Velde, Fijs W B van Leeuwen
PURPOSE OF REVIEW: To provide an overview of the developments made for virtual- and augmented-reality navigation procedures in urological interventions/surgery. RECENT FINDINGS: Navigation efforts have demonstrated potential in the field of urology by supporting guidance for various disorders. The navigation approaches differ between the individual indications, but seem interchangeable to a certain extent. An increasing number of pre- and intra-operative imaging modalities has been used to create detailed surgical roadmaps, namely: (cone-beam) computed tomography, MRI, ultrasound, and single-photon emission computed tomography...
December 22, 2017: Current Opinion in Urology
https://www.readbyqxmd.com/read/29276808/efficient-groupwise-registration-for-brain-mri-by-fast-initialization
#15
Pei Dong, Xiaohuan Cao, Jun Zhang, Minjeong Kim, Guorong Wu, Dinggang Shen
Groupwise image registration provides an unbiased registration solution upon a population of images, which can facilitate the subsequent population analysis. However, it is generally computationally expensive for performing groupwise registration on a large set of images. To alleviate this issue, we propose to utilize a fast initialization technique for speeding up the groupwise registration. Our main idea is to generate a set of simulated brain MRI samples with known deformations to their group center. This can be achieved in the training stage by two steps...
2017: Machine Learning in Medical Imaging
https://www.readbyqxmd.com/read/29276135/-external-beam-radiotherapy-cone-beam-computed-tomography-based-dose-calculation
#16
A Barateau, M Céleste, C Lafond, O Henry, S Couespel, A Simon, O Acosta, R de Crevoisier, N Périchon
In external beam radiotherapy, the dose planning is currently based on computed tomography (CT) images. A relation between Hounsfield numbers and electron densities (or mass densities) is necessary for dose calculation taking heterogeneities into account. In image-guided radiotherapy process, the cone beam CT is classically used for tissue visualization and registration. Cone beam CT for dose calculation is also attractive in dose reporting/monitoring perspectives and particularly in a context of dose-guided adaptive radiotherapy...
December 21, 2017: Cancer Radiothérapie: Journal de la Société Française de Radiothérapie Oncologique
https://www.readbyqxmd.com/read/29276002/intensity-based-volumetric-registration-of-magnetic-resonance-images-and-whole-mount-sections-of-the-prostate
#17
Are Losnegård, Lars Reisæter, Ole J Halvorsen, Christian Beisland, Aurea Castilho, Ludvig P Muren, Jarle Rørvik, Arvid Lundervold
OBJECTIVE: Magnetic Resonance Imaging (MRI) of the prostate provides useful in vivo diagnostic tissue information such as tumor location and aggressiveness, but ex vivo histopathology remains the ground truth. There are several challenges related to the registration of MRI to histopathology. We present a method for registration of standard clinical T2-weighted MRI (T2W-MRI) and transverse histopathology whole-mount (WM) sections of the prostate. METHODS: An isotropic volume stack was created from the WM sections using 2D rigid and deformable registration combined with linear interpolation...
December 15, 2017: Computerized Medical Imaging and Graphics: the Official Journal of the Computerized Medical Imaging Society
https://www.readbyqxmd.com/read/29262513/-calculating-the-hausdorff-distance-based-on-the-scripting-in-raystation-treatment-planning-system
#18
F B Guo, C S Cai, W J Zhang, J S Hong, L Z Lan, X Y Chen
Objective: To calculate out the Hausdorff distance based on the scripting in RayStation treatment planning system, which was then applied in measuring the deformation error of brain stem during image automatic registration between CT and MR. Methods: Scripting was edited in RayStation system (version 4.7) by using IronPython. The set of point coordinates on the contour of any two region of interest (ROI) had been found firstly, then the Hausdorff distance between the two point sets was calculated out. A graphical user interface (GUI) was designed by using XAML to acquire the visualized output of Hausdorff distance...
December 23, 2017: Zhonghua Zhong Liu za Zhi [Chinese Journal of Oncology]
https://www.readbyqxmd.com/read/29259943/a-robust-and-accurate-non-rigid-medical-image-registration-algorithm-based-on-multi-level-deformable-model
#19
Yanli Wan, Hongpu Hu, Yanli Xu, Quan Chen, Yan Wang, Dongping Gao
Background: Compared to the rigid image registration task, the non-rigid image registration task faces much more challenges due to its high degree of freedom and inherent requirement of smoothness in the deformation field. The purpose was to propose an efficient coarse-to-fine non-rigid medical image registration algorithm based on a multilevel deformable model. Methods: In this paper, a robust and efficient coarse-to-fine non-rigid medical image registration algorithm is proposed...
December 2017: Iranian Journal of Public Health
https://www.readbyqxmd.com/read/29251777/an-adaptive-motion-regularization-technique-to-support-sliding-motion-in-deformable-image-registration
#20
Yabo Fu, Shi Liu, H Harold Li, Hua Li, Deshan Yang
PURPOSE: Isotropic smoothing has been conventionally used to regularize deformation vector fields (DVFs) in deformable image registration (DIR). However, the isotropic smoothing method enforces global smoothness and therefore cannot accurately model the complex tissue deformation, such as sliding motion at organ boundaries. To accurately model and estimate sliding tissue motion, an adaptive direction-dependent DVF regularization technique was developed in this study. METHODS: A DVF is computed and updated iteratively by minimizing the intensity differences between the images...
December 18, 2017: Medical Physics
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