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ISMRM 2017 华人学者传统展板选:采集、重建和分析(1)

2017-04-26 医学影像学英语


ISMRM 25th Annual Meeting & Exhibition • 22-27 April 2017 • Honolulu, HI, USA

Traditional Poster Session: Acquisition, Reconstruction & Analysis
1272 -1296
1297 -1316
1317 -1331
1332 -1366
1367 -1386
1387 -1406
1407 -1429
1430 -1476
1477 -1511
1512 -1531

 Motion Correction
Traditional PosterAcquisition, Reconstruction & Analysis
 Monday, 24 April 2017
Exhibition Hall 1272-1296 08:15 - 10:15
 

1275.   

 

Pei Huang, David Hayes, Marta Correia

Prospective motion correction for MRI has been shown to greatly improve image quality for structural scans but its impact on fMRI data is still unclear. In this work, we studied the effectiveness of prospective motion correction by analysing the accuracy of the tracking system and looking at the effects of motion correction on resting-state fMRI with no instructed subject motion. 

 

1280.   

 

Weidao Chen, Bo Peng, Yi Sun, Gang Chen, Anna Roe, Yakang Dai, Xiaotong Zhang

Accurate subject-specific 3D modeling of macaque brain with anatomical subdivisions is important for neuroscience, neurophysiology and engineering researches. In this study, we have proposed a feasible approach for automatically creating 3D models of macaque brain based on in vivo MR images. A 3D template of macaque brain, consisting of scalp, skull, grey matter, white matter, and cerebrospinal fluid, was firstly constructed from 7T T1w images over an anesthetized macaque; then, by implementing symmetric feature-based pairwise registration method, this template was used to register another in vivo 7T dataset of macaque brain, which enables automatic and subject-specific 3D macaque brain modeling.

 

1284.   

Tao Zhang, Ty Cashen, Kang Wang, André Fischer, Ersin Bayram

Stack of stars trajectory with golden angle ordering provides better motion robustness than Cartesian imaging for abdominal MRI. However, image reconstruction for non-Cartesian datasets is usually time-consuming, especially for datasets with high-density coil arrays. While additional motion correction methods can improve image quality for stack of stars, they often further increase the reconstruction time. In this work, we aim to reduce the reconstruction time for stack of stars using coil compression and improve motion robustness with a similar reconstruction time using soft gating.

 

1285.   

 Li Feng, Hersh Chandarana, Tiejun Zhao, Mary Bruno, Daniel Sodickson, Ricardo Otazo

This work compares golden-angle stack-of-stars sampling and golden-angle Cartesian sampling for free-breathing liver MRI with eXtra-Dimensional (XD) compressed sensing reconstruction. For Cartesian sampling, the phase-encoding steps in the ky-kz plane are segmented into multiple interleaves that rotate at a golden angle. Each interleave starts from the center (ky=kz=0) of k-space and follows a pseudo-radial pattern on a Cartesian grid. Results from this initial study suggest that golden-angle Cartesian sampling achieves higher effective spatial resolution than radial sampling, but it still suffers from residual ghosting artifacts due to respiratory motion for free-breathing liver imaging. 

 

1276.   

 Pei Huang, Nikolaus Kriegeskorte, Richard Henson, Arjen Alink, Marta Correia

Prospective Motion Correction (PMC) using an optical tracking system has been shown to improve data quality. We conducted a study on 18 subjects using robust visual stimuli to quantify the effectiveness of PMC on task-based fMRI. Our results show that PMC improves voxel-to-voxel registration across time and leads to better contrast-to-noise ratio. This is particularly evident in analyses which are more sensitive to inaccurate voxel registration and motion-induced noise. 

 

1287.   

 Wanyong Shin, Erik Beall, Mark Lowe

Participants in block design finger tapping fMRI have a tendency to have paradigm coherent head motion. This finding appears to be very strong in HCP data, which utilizes spatially and temporally accelerated SMS sequence. We have introduced slice-oriented motion correction method (SLOMOCO1), and found SLOMOCO removed the head motion efficiently in HCP data, especially in the case that head motion pattern is synchronized to task paradigm. In this study, we compared the various motion correction methods in finger tapping fMRI HCP data.

 

1289.   

 Gaojie Zhu, Xiang Zhou, Hai Luo, Bin Wang, Xia Liu, Ziyue Wu, Leping Zha, Qing-San Xiang

Patient motion produces artifacts in MRI due to k-space data corruption. Ghosted images can be considered as a combination of ghost-free images and ghost masks. If two ghosted images contain the same ghost-free image component and different ghost components, the images and the ghost components can be separated. For images fully sampled with array coils, multiple images can be produced with parallel reconstruction with differently selected raw data subsets. In this work, we propose a new motion artifacts reduction algorithm, which regenerates a new k-space dataset based on data consistency, and then decomposes images into mostly ghost-free images and ghost masks.

 

1293.   

 Bian Li, Huajun She, Shu Zhang, Jochen Keupp, Ivan Dimitrov, Albert Montillo, Ananth Madhuranthakam, Robert Lenkinski, Elena 

VinogradovIn image registration, mutual information (MI) has proved to be an effective similarity measure and is widely used for medical image registration. However, the MI algorithm does not consider spatial dependencies of voxels and introduces significant errors when registering images with large intensity changes, like in Z-spectral images of CEST-MRI. This abstract shows that by the incorporation of structural information the SMI algorithm demonstrates robust performance registering Z-spectral images with large and complex intensity variations.

 

1273.   

 Zhongbiao Xu, Mengye Lyu, Edward Hui, Yingjie Mei, Zhifeng Chen, Wufan Chen, Ed X. Wu, Yanqiu Feng

The recently proposed magnetic resonance fingerprinting (MRF) technique demonstrates to be motion insensitive, but the early motion during the acquisition can still lead to severe errors in parameter quantification. In this study, we present a novel motion correct method for MRF based on sliding-window reconstruction and image registration.

 

1272.   

 Junshen Xu, Yibo Zhao, Kui Ying

Joint Reconstruction (JR) is an important approach to utilize the similarity of PET and MRI in simultaneous PET/MR imaging. For now, almost all the JR models ignore the effect of motion during scan, leading to blurring in images. We propose a motion correction method under the framework of JR, assuming that PET images and MRI images share exactly the same motion field and using a B-spline free deformation model to describe the motion. Both simulation and patient study show that the proposed method can reduce the blurring caused by motion in PET and MR images.

 

More Motion
Traditional Poster

Acquisition, Reconstruction & Analysis

 

Monday, 24 April 2017

Exhibition Hall 08:15 - 10:15
 

1301.   

Jiaen Liu, Peter van Gelderen, Jacco de Zwart, Jeff Duyn

Subject motion is a common source of artifact in MRI scans. Various navigator techniques have been developed to monitor motion and correct motion artifacts. In this study, a new approach was developed to extract 3D motion information of the head based on three orthogonal 1D gradient-encoded echoes acquired in about 2 ms. Complementary positional information carried by the individual sensitivity profiles of a receive array was exploited. The method was evaluated in experiments. It suggested the estimated motion parameters were within ±0.5° and ±0.5 mm accuracy in reference to co-registered head images in various positions with rotations up to ±4°.

 

1302.   

Jiaen Liu, Jacco de Zwart, Peter van Gelderen, Jeff Duyn

In this study, changes of the B0 field inside the brain due to head motion were measured and analyzed. The sources contributing to this change include a static field introduced by the relative position of the head to the body and the shim coils, and a dynamic one from the head’s orientation and its susceptibility. The experimental results suggest that the component from the head and/or body has a strong magnitude and complex spatial pattern, which makes it difficult to be measured with simple navigators. This B0 field change should be properly taken into account for motion correction.

 

1308.   

Zijing Dong, Fuyixue Wang, Yishi Wang, Hua Guo

Readout-segmented EPI (RS-EPI) and interleaved-EPI (iEPI) are the two most widely used multishot EPI techniques for high resolution DWI. Many methods have been proposed to correct the motion-induced phase variations and rigid-motion in RS-EPI and iEPI. To compare the performance of motion correction in RS-EPI and iEPI, DWI and DTI simulations were designed. The correction methods we implemented for RS-EPI and iEPI take account of motion-induced phase variation, bulk motion and altered diffusion gradient orientation due to rotation. In our test, iEPI show less artifacts, however the b-matrix correction of RS-EPI is more straightforward with better accuracy.

 

1309.   

Wei Liu, Kun Zhou, Fang Dong

The 2D-PACE technique has been proved to be superior to conventional respiratory triggering techniques for imaging the abdominal region because it could detect more accurate respiratory waveform, which is already widely used in single shot EPI for high quality abdominal diffusion weighted imaging. The readout-segmented EPI features much shorter echo spacing compared with single shot EPI and consequently enjoys less distortion. In this study, the 2D-PACE technique is integrated into a readout-segmented EPI sequence and makes high resolution abdominal diffusion images with less distortion and image blurring.


 

1310.   

Chang Gao, Chao Ma, Yibo Zhao, Kui Ying, Yoann Petibon, Jerome Ackerman, Chuan Huang, Georges El Fakhri, Jinsong Ouyang

Head motion degrades image quality through loss of resolution in brain PET/MR. This work presents a wireless MR active marker based method to track and correct head motion for both PET and MRI. The proposed rigid motion correction method has been validated using a phantom study on a clinical PET/MR scanner.

 
 

RF Pulse Design
Traditional Poster

Acquisition, Reconstruction & Analysis

 

Monday, 24 April 2017

Exhibition Hall 08:15 - 10:15


1327.   

Qing Li, Congyu Liao, Huihui Ye, Ying Chen, Hongjian He, Qiuping Ding, Jianhui Zhong

A squeezed variable density spiral (SVDS) trajectory was proposed to reduce SAR and peak RF power in 2D RF pulse design using parallel transmission (pTX). SVDS was generated by applying a pointwise squeezing factor to conventional variable density spiral (CVDS) trajectory. Compared to CVDS, SVDS can reduce peak RF and SAR by close to 40%, with minimal increase in the normalized root mean square error (NRMSE) of the excitation profile and pulse duration.

 

1325.   

Li Zhao, David Alsop

Fast spin echo acquisition plays an essential role in a worthy of MRI applications. But the flip angles of refocus pulses are conventionally designed intuitively. In this work, we proposed a global scheme that can provide a comprehensive framework for flip angled design and proposed the requirement with a well-proposed optimization problem. The performance of the proposed method was demonstrated on the correction of T2 blurring with numerical simulation.

 

Multimodal & Multiparametric
Traditional Poster

Acquisition, Reconstruction & Analysis

 

Monday, 24 April 2017

Exhibition Hall 08:15 - 10:15


1337.   

Chang Gao, Junshen Xu, Bowen Fan, Jiajin Liu, Kui Ying

In simultaneous PET/MR imaging, PET attenuation correction is based on MRI, unlike PET/CT systems, which directly use CT measurements. Various approaches have been developed based on templates, atlas information, direct segmentation of T1-weighted MR images. In the present study, we introduced two approaches of UTE-based attenuation correction for simultaneous PET/MR imaging focusing on children’s brain, including segmentation-based method and Support Vector Machine (SVM) regression method. The results have been compared with Gaussian Mixture Regression (GMR) model method.

 

1345.   

Zhiyang Fu, Zhitao Li, Mahesh Keerthivasan, Diego Martin, Maria Altbach, Ali Bilgin

Quantitative MRI requires accurate parameter estimation but long acquisition time limits the use of conventional techniques in the clinic. Recently, several T1 and T2 mapping methods based on highly accelerated radial trajectories have been proposed. The reconstruction problems in these works are formulated as unconstrained optimizations and solved using the non-linear conjugate gradient method. We propose an alternative formulation based on the alternating direction method of multipliers which reduces reconstruction time without compromising reconstruction quality.

 

1356.   

Yang Li, SHUAI Wang, Edward Hui, Di Cui, Hing-Chiu Chang, Yik-Chung Wu

Magnetic resonance fingerprinting (MRF) is a novel and efficient method for the estimation of MR parameters, such as off-resonance (DB­0), proton density (PD), T1 and T2. Because of the highly undersampled readout that is conventionally used, large number of dynamics (e.g. <1000) are often acquired for maintaining the fidelity of MR parameter estimations (a.k.a. dictionary matching). In this study, we propose a new algorithm, MRF reconstruction using majorization-minimization (mmMRF), such that fidelity of dictionary matching can remain similar even when significantly less number of dynamics are available. 

 

1357.   

Kun Yang, Yun Jiang, Mark Griswold, Vikas Gulani, Debra McGivney

An important issue in magnetic resonance fingerprinting (MRF) is the precision of pattern matching.  The sensitivity of inner product between the signal and dictionary can be corrupted by closely spaced dictionary entries.  In order to make MRF more sensitive and precise, four modifications of the MRF dictionary are proposed. The performance of each method is tested and compared over 30 repetitions in a phantom scan.  Some of the methods demonstrate a significant reduction in the error over the original MRF dictionary. 

 

1363.   

Zhengyang Zhou, Jian He, Weibo Chen

Twenty-six NPC patients underwent serial T1rho-weighted imaging to evaluate the dynamic changes of parotid glands in patients undergoing intensity-modulated radiation therapy. Parotid volumes, T1rho values, mean radiation doses, and xerostomia degrees were recorded. Change rates of T1rho values were correlated with atrophy rates, mean radiation doses and xerostomia degrees. During RT, parotid volume decreased and parotid T1rho values increased significantly. The change rate of T1rho value correlated with the atrophy rate significantly at post-RT. Intra- and interobserver reproducibility of T1rho measurements were excellent. Dynamic changes of radiation-induced parotid damage in NPC patients underwent IMRT could be evaluated by T1rho-weighted imaging.

 
 

Elastography
Traditional Poster

Acquisition, Reconstruction & Analysis

 

Monday, 24 April 2017

Exhibition Hall 08:15 - 10:15
 

1373.   

Lumeng Cui, Paul Babyn, Francis Bui, Niranjan Venugopal

MRE has the ability to distinguish between elastic properties of the tissue. Furthermore, it is maturing as a technique to differentiate normal and cancerous tissue. In this work we present a strategy to establish  MRE data, and present a method to incorporate this information into a radiation treatment planning framework. This new information is used to evaluate the efficacy of dose escalation to dominant intraprostatic lesions using a volumetric modulated arc therapy technique.    

 

1379.   

Hui Wang, Suraj Serai, Tom Cull, Jonathan Dillman, Charles Dumoulin, Andrew Trout

While MRE based on 2D gradient recalled echo (GRE) MRI is FDA approved at 1.5T, the utility of 2D GRE MRE in the liver at 3T is limited by susceptibility effects and relatively long echo times that results in less SNR.  MRE performance, particularly at 3T, can be improved by developing a faster technique that is less sensitive to liver T2* effects. In this work, we describe the development of SE-EPI MRE and its validation with respect to 2D GRE MRE in phantoms and healthy volunteers.


 

1384.   

Luyao Cai, Claus Pedersen, Corey Neu

We developed an inverse modeling approach for magnetic resonance elastography of tissues undergoing finite (large) deformations at physiologically-relevant loading rates. Inverse modeling was designed to directly incorporate displacement-encoded MRI with topology optimization to reveal stiffness distributions. The approach was validated using forward simulations with known material properties and boundary conditions, and sensitivity analyses. Inverse modeling may enable noninvasive characterization of material stiffness for complex tissues like articular cartilage in disease and repair.


 


From:http://www.ismrm.org/17/program_files/TP01.htm#more

ISMRM 2017 ANNUAL MEETING DAILY FEATURE——Saturday 22 April

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