| Computer # |
| 4438.
 | 113 | Amide proton transfer imaging corrected by apparent diffusion coefficient to detect response of chemotherapy in bone and soft tissue sarcomas Koji Sagiyama1, Takeshi Kamitani1, Yuzo Yamasaki1, Takuya Hino1, Kosuke Tabata1, Hidetake Yabuuchi2, Kousei Ishigami1, Makoto Endo3, Taro Mori4, and Yoshinao Oda4
1Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan, 2Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan, 3Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan, 4Department of Anatomic Pathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan Keywords: CEST / APT / NOE, CEST & MT, bone and soft tissue sarcoma Motivation: Evaluating the response to chemotherapy based on volume changes is often difficult in bone and soft tissue sarcomas; therefore, new molecular imaging techniques are required. Goal(s): To investigate whether amide proton transfer (APT) imaging combined with apparent diffusion coefficient (ADC) accurately reflects treatment efficacy in bone and soft tissue sarcomas. Approach: An MRI was performed before and after chemotherapy in 12 patients who received preoperative chemotherapy. Tumor volume, APT, and ADC were compared before and after treatment and correlated with postoperative pathology specimens. Results: Only APT imaging with ADC correction correctly reflected the effect of preoperative chemotherapy. Impact: The present study demonstrates that a new molecular imaging technique can accurately determine the efficacy of chemotherapy for bone and soft tissue sarcomas. This will help to determine the optimal course of treatment and improve patient prognosis. |
| 4439.
 | 114 | Glucose Chemical Exchange Saturation Transfer MRI for Predicting the Histological Grade of Rectal Cancer Nan Meng1, Bo Dai1, Xue Liu1, Yaping Wu1, Xuan Yu1, Zheng Li1, Zhiwei Shen2, and Meiyun Wang1
1Henan Provincial People’s Hospital, zhengzhou, China, 2Philips Healthcare, Beijing, China Keywords: CEST / APT / NOE, CEST & MT Motivation: The histological grade of rectal cancer has a considerable involvement in treatment strategies and prognosis in relevant patients. Goal(s): To evaluate the utility of glucose chemical exchange saturation transfer (glucoCEST) MRI with non-contrast injection in predicting the histological grade of rectal cancer. Approach: This prospective analysis included 60 patients with rectal cancer who underwent pelvic glucoCEST, APTWI, and DWI. Results: Elevated MTRasym (1.2 ppm), MTRasym (3.5 ppm) values and lower ADC values were observed in the high-grade group compared with low-grade cases (all P < 0.01). The AUCs of MTRasym (1.2 ppm), MTRasym (3.5 ppm), and ADC were 0.792, 0.839, and 0.855, respectively. Impact: These preliminary data demonstrate that glucoCEST MRI without contrast injection has the potential to provide a non-invasive assessment of histological grade in rectal cancer and add value to current tools used for the differentiation between high- and low-grade rectal cancer. |
| 4440.
 | 115 | Can the Relayed Nuclear Overhauser Enhancement Effect at -1.6 ppm Provide Unique Contrast in an Ischemic Stroke Model? Yee Kai Tee1, Swee Qi Pan1, and Rami Hayek1
1Department of Mechatronics and Biomedical Engineering, Lee Kong Chian Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Kajang, Malaysia Keywords: CEST / APT / NOE, CEST & MT Motivation: NOE(-1.6 ppm) may provide vital information about a different stage of the ischemic cascade, allowing for a more in-depth analysis of ischemic injury. Goal(s): To investigate whether NOE(-1.6 ppm) can uncover new insights into ischemic injury. Approach: CEST data in an ischemic stroke model were acquired to compare the information provided by NOE(-1.6 ppm) with that obtained from PWI, DWI, and APT. Results: NOE(-1.6 ppm) was observed to be lower in the ischemic region, with the deficit areas being equal to or larger than the ADC deficit areas but smaller than the AREX(3.5 ppm) deficit areas. Impact: NOE(-1.6 ppm) offers unique contrast compared to PWI, DWI, and APT imaging in
ischemic tissues. Altogether, the mismatches reveal four zones of increasing sizes within the ischemic
tissue, potentially reflecting different pathophysiological information. |
| 4441.
 | 116 | A generalized QUCESOP method for amide and NOE quantification in rat brain tumor Yi Wang1, Yang Fan2, Xiaolei Song3, and Jia-Hong Gao4
1Public Health Science and Engineering College,Tianjin University of Traditional Chinese Medicine, Tianjin, China, 2MR Research China, GEHealthcare, Beijing, China, 3Center for Biomedical Imaging Research, School of Medicine, Tsinghua University, Beijing, China, 4Center for MRI Research, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China Keywords: CEST / APT / NOE, CEST & MT Motivation: Current CEST quantification methods only calculated the fractional concentration fb and the exchange rate kb for each solute pool, but consider R2b as a constant. Goal(s): To quantify the change of b, kb and R2b corresponding to the amide and NOE pool in brain tumor imaging of rats. Approach: Partial Z-spectra around the target frequency offsets were acquired using several saturation amplitudes, and the QUCESOP method was employed to fit the parameters of the amide solute and the “NOE solute” respectively. Results: Tumor exhibited higher R2b and lower fb for “NOE solute”, with a slightly-elevated amide pool size, compared with the normal tissue. Impact: Tumor displayed an increase of R2b and a decrease of fb for the “NOE solute”, that originated from the aliphatic protons on the macromolecular pool. The larger R2b may reflect the increased cell density in the tumor region. |
| 4442.
 | 117 | Multi-center comparison of whole-brain high-resolution CEST mapping at ultra-high field using PUSHUP saturation Yannik Völzke1, Daniel Löwen1, Rüdiger Stirnberg1, Eberhard Daniel Pracht1, Laurent Lamalle2, Pål Erik Goa3,4, and Tony Stöcker1,5
1German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany, 2GIGA-Cyclotron Research Centre-In Vivo Imaging, University of Liège, Liege, Belgium, 3Department of Physics, Norwegian University of Science and Technology, Trondheim, Norway, 4Clinic of Radiology and Nuclear Medicine, St.Olavs University Hospital HF, Trondheim, Norway, 5Department of Physics and Astronomy, University of Bonn, Bonn, Germany Keywords: CEST / APT / NOE, CEST & MT Motivation: CEST suffers from saturation inhomogeneities, especially at ultra-high fields. Universal pulses enable calibration-free mitigation of these inhomogeneities. However, it is not obvious how well PUSHUP translates to different scanners. Goal(s): The goal of this work is to evaluate the feasibility of PUSHUP-CEST to obtain homogeneous whole-brain, high-resolution CEST maps in multi-center studies. Approach: PUSHUP was calculated using a joined database of three sites. Multiple CEST measurements were performed at each site. The mean CEST amplitudes were compared in four brain segments. Results: The resulting CEST maps were homogeneous and without major image artifacts. No significant bias could be found between sites. Impact: PUSHUP allows for high-resolution, whole-brain CEST mapping at 7T. The feasibility of PUSHUP saturation for multi-center CEST studies and the use of joined databases for pulse calculation are demonstrated. No site-bias is found. This fosters CEST mapping in large-scale studies. |
| 4443.
 | 118 | Simultaneous Observation of Distinct Phosphocreatine and Creatine CEST Peaks in Exercised Human Skeletal Muscle at 5T Xinran Chen1,2, Xi Xu1, Chongxue Bie1, Lin Chen2, and Yang Zhou1
1Key Laboratory for Magnetic Resonance and Multimodality Imaging of Guangdong Province, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China, 2Department of Electronic Science, Xiamen University, Xiamen, China Keywords: CEST / APT / NOE, CEST & MT, Muscle, creatine, phosphocreatine, CK reaction Motivation: PCrCEST and CrCEST contrasts are weak and indiscernible in clinical settings (≤ 3 T), limiting the accuracy of quantification. Goal(s): To develop an accurate and reliable PCrCEST and CrCEST method in human skeletal muscle at 5 T. Approach: The optimal saturation scheme was investigated. Two-peak PLOF method was employed for quantification. Plantar flexion exercise was conducted to validate the performance of the proposed method. Results: Distinct PCrCEST and CrCEST peaks can be observed simultaneously at 5T. The transition between PCr and Cr was clearly observed in a volunteer during and after exercise. Impact: Improved
accuracy and reliability of PCrCEST and CrCEST in human skeletal muscle can be
obtained at 5T. The distinct CEST peak at 2.0 ppm immediately after exercise suggests
that the in vivo CrCEST is a slow-exchanging process. |
| 4444.
 | 119 | A unified framework of tumor segmentation and response assessment in patients with malignant gliomas using structural and APT-weighted MRI Puyang Wang1, Qianqi Huang2, Jingpu Wu3, Mingchao Liu4, Keyi Chai5, Yunfan Zou5, Jinyuan Zhou1, and Shanshan Jiang1
1Department of Radiology, Johns Hopkins University, Baltimore, MD, United States, 2Department of Computer Science, Johns Hopkins University, Baltimore, MD, United States, 3Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD, United States, 4Department of Applied Mathematics and Statistics, Johns Hopkins University, Baltimore, MD, United States, 5Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States Keywords: CEST / APT / NOE, CEST & MT Motivation: Amide protein transfer-weighted (APTw) MRI has been validated to accurately detect recurrent malignant gliomas across different studies. However, APTw image interpretation is time consuming and requires professional knowledge. Goal(s): Our goal was to develop a reliable, automated imaging diagnostic tool to assess malignant glioma response to therapies are urgently needed. Approach: We developed and verified a unified CNN-based deep-learning framework for both tumor segmentation and tumor progression assessment by adding APTw MRI data to structural MR images as model input. Results: The use of APTw images can improve not only diagnostic accuracy but also segmentation performance to structural MRIs. Impact: The proposed deep-learning method could be a
highly efficient solution that could help clinical experts to make precise
diagnoses for patients with post-treatment gliomas. |
| 4445.
 | 120 | Cell Surface Mannose Overexpression as New CEST MRI Biomarker for Glioblastoma Aggressiveness Behnaz Ghaemi1, Shreyas Kuddannaya1, Hernando Lopez Bertoni2, John Joseph Laterra2, Guanshu Liu3, and Jeff W.M Bulte4
1Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, Johns Hopkins University, Baltimore, MD, United States, 2Department of Oncology, Department of Neurology, Johns Hopkins University, Baltimore, MD, United States, 3Russell H. Morgan Department of Radiology and Radiological Science, F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Inc., Johns Hopkins University, Baltimore, MD, United States, 4Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, Department of Oncology, F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Inc., Johns Hopkins University, Baltimore, MD, United States Keywords: CEST / APT / NOE, CEST & MT, Glioblastoma, Cancer stem cells, Label-free CEST Motivation: Non-invasive grading of glioblastoma (GBM) aggressiveness is critical for choosing a proper treatment paradigm Goal(s): To develop a label-free MRI technique that can probe the presence of cancer stem cells (CSCs) in GBM. Approach: To detect high mannose N-linked glycans overexpressed on mesenchymal CSCs with mannose-weighted (MANw) CEST MRI. Results: MANw CEST MRI was able to produce a distinct signal for highly aggressive GBM tumor spheres but not for low aggressive ones, which corresponded to the histoptahological presence or absence of mannose expression. Impact: We present a simple, non-invasive diagnostic approach for assessment of glioblastoma aggressiveness, which can be immediately implemented as an add-on to current MRI protocols. |
| 4446.
 | 121 | Lorentzian fitting of Average Rotation of Saturation Effects (AROSE) CEST spectra for quantification in stroke Julius Juhyun Chung1,2 and Tao Jin1
1Radiology, University of Pittsburgh, Pittsburgh, PA, United States, 2Emory National Primate Research Center, Emory University, Atlanta, GA, United States Keywords: CEST / APT / NOE, CEST & MT Motivation: Fitting of CEST spectra is obscured by MT, direct water saturation, and broad fast exchange peaks which result in contamination of quantified signals. Goal(s): Using AROSE spectra for fitting simplifies CEST quantification by reducing the need for isolation of CEST signals due to preemptive filtering. Approach: Fitting was first performed on simulated spectra at different exchange rates and then applied to in vivo data. Results: Our results in MCAO rodents showed that quantification of CEST signal from AROSERRex spectra resulted in low fitting residuals with robust peaks at 3.6, 2.6, and 2 ppm and minimal contamination from MT and fast exchanges. Impact: Fitting using AROSE-CEST spectra improves
quantification of CEST exchange by minimizing contributions from broad fast
exchanges and other contaminations such as MT which have been challenges for
traditional fitting methods such as multiple -pool Lorentzian fitting. |
| 4447.
 | 122 | Altered amide in substantia nigra is concordant with motor asymmetry in Parkinson's disease: a multipool CEST study Yaotian Tian1,2, Xinyang Li1, Xiaonan Wang1, Dandan Shang1, Dandan Zheng3, Chunmei Li1, and Min Chen1
1Department of Radiology, Department of Radiology, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, China, 2Graduate School of Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China, 3Clinical & Technique Support, Philips Healthcare, Beijing, China Keywords: CEST / APT / NOE, CEST & MT, Parkinson's Disease Motivation: The pathophysiological changes associated with motor asymmetry within midbrain nucleus in Parkinson’s Disease (PD) remains unclear. Goal(s): We aimed to explore the mesencephalic change by using four-pool model-based chemical exchange saturation transfer (CEST) analysis in asymmetrical PD. Approach: The difference of four-pool model-based CEST parameters in more and less affected side of mesencephalic region were compared, and its associations with motor asymmetry were estimated. Results: Our data revealed the inherent asymmetry on nigral amide and relayed nuclear Overhauser effect (rNOE) in asymmetric PD patients, and the substantial consistency between imaging laterality of nigral amide and motor laterality in significant asymmetrical PD. Impact: Our findings could benefit a
better understanding of the mechanisms contributing to the asymmetry of PD and
provide promising no-invasive neuroimaging biomarkers related to lateralization
in PD. |
| 4448.
 | 123 | The impact of deep learning based image reconstruction on CEST MRI for distinguishing inactive from active thyroid-associated ophthalmopathy Yunmeng Wang1,2, Yuanyuan Cui2, Jiankun Dai3, Qingqing Wen3, and Yi Xiao2
1Graduate School of Bengbu Medical College,, Bengbu, China, 2Department of Radiology, Second Affiliated Hospital of Naval Medical University, Shanghai, China, 3MR Research, GE Healthcare, Beijing, China Keywords: CEST / APT / NOE, CEST & MT, thyroid-associated ophthalmopathy, diffusion weighted imaging, deep learning reconstruction Motivation: Thyroid-associated ophthalmopathy (TAO) is characterized by accumulation of collagen in extraocular muscle. CEST-MRI can evaluate the collagen content by focusing on amide compound. However, CEST effect is small and sensitive to low image SNR. A vendor-provided deep learning reconstruction (DLR) algorithm can dramatically increase image SNR. Goal(s): Investigate if CEST-MRI can distinguish inactive from active TAO and the impact of DLR on its diagnostic performance. Approach: 11 active and 12 inactive TAO were enrolled. CEST imaging was reconstructed with DLR and conventional reconstruction. Results: DLR can significantly increase SNR of CEST imaging and improved the diagnostic performance for discriminating inactive from active TAO. Impact: The treatment of TAO depends on the disease phase. DLR image reconstruction improved the performance of CEST in differentiation between inactive and active TAO. It would help in the evaluation and management of TAO patients. |
| 4449.
 | 124 | APTw/CEST-MRI for body oncology with SPIR fat suppression using improved Z-spectral modeling for olefinic fat components Jochen Keupp1, Holger Eggers1, Ivan E Dimitrov2,3, and Elena Vinogradov3,4
1Philips Research, Hamburg, Germany, 2Philips Healthcare, Gainesville, FL, United States, 3Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States, 4Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX, United States Keywords: CEST / APT / NOE, CEST & MT, Z-spectral fitting, olephinic fat, aliphatic fat Motivation: Fat-artifacts are challenging in CEST-MRI for body applications as they overlap spectrally with clinically relevant signals like amide or hydroxyl. Goal(s): Improve the quality of in vivo fat correction based on previously explored Z-spectral fitting of data obtained with SPIR fat suppression. Approach: Olefinic fat is modeled separately while scaling and inverting aliphatic components. Fitting was tested on Z-spectral data from breast ROIs with variable fat content. Results: The new model is accurate for a large range of fat fractions. The opposite phase of aliphatic and olefinic fat components provides a better explanation for the observed Z-spectra in vivo. Impact: Understanding and accurate modeling of fat signals in fat-suppressed APT/CEST-MRI
will allow unbiased assessment of CEST effects in body-oncology (breast, kidney
cancer). |
| 4450.
 | 125 | Improved Differentiation of Glioma Grades through Fluid Exponential Suppression in Chemical Exchange Saturation Transfer (CEST) Imaging Longjie Zhou1, Hongxi Zhang2, Xingwang Yong1, Haichun Zhou2, Jing Guo2, Weibo Chen3, Zhipeng Shen4, and Yi Zhang1
1Key Laboratory for Biomedical Engineering of Ministry of Education, Department of Biomedical Engineering, College of Biomedical Engineering & Instrument Science, Zhejiang University, Hangzhou, Zhejiang, China, 2Department of Radiology, Children’s Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China, 3Philips Healthcare, Shanghai, China, 4Department of Neurosurgery, Children’s Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China Keywords: CEST / APT / NOE, CEST & MT Motivation: Fluid-induced artifacts often hamper differentiation between high- and low-grade gliomas in CEST imaging. Goal(s): Our goal was to develop a novel fluid exponential suppression factor to eliminate fluid-related artifacts. Approach: We extended the original linear correction factor into a nonlinear exponential factor. The metrics with and without fluid suppression factors were compared using a dataset of 140 glioma patients. Results: CEST metrics combined with the fluid exponential suppression factor substantially reduced the fluid-related artifacts and yielded higher AUCs for grading gliomas than linear correction and no correlation. Impact: The novel
fluid exponential suppression strategy can substantially improve the quality of
CEST maps and enhance the performance of diagnosing gliomas. The proposed
method is easy to adopt and can be applied to existing data retrospectively. |
| 4451.
 | 126 | Mutli-modal MRI confirms HIV-1-linked neurometabolomic impairments in humanized mice Gabriel Gauthier1, Aditya Bade2, Balasrinivasa Sajja1, Mariano Uberti1, Santhi Gorantla2, Micah Summerlin2, and Yutong Liu1
1Department of Radiology, University of Nebraska Medical Center, Omaha, NE, United States, 2Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, United States Keywords: CEST / APT / NOE, CEST & MT, HIV Motivation: While anti-retroviral therapy (ART) is essential for combating the type-one human immunodeficiency virus (HIV-1), patients with undetectable viral load still experience HIV-associated neurocognitive disorders. Goal(s): We aimed to use the chemical exchange saturation transfer (CEST) effects of brain metabolites with MRI to elucidate HIV-associated neurocognitive outcomes on ART patients. Approach: Humanized mice were infected with HIV-1, then given daily treatment of ART or vehicle. CEST-MRI and MRS were used to evaluate brain metabolites at four key timepoints. Results: Untreated mice showed declining 2ppm and 3ppm CEST signal in key brain regions, alongside increasing NOE signal. This was partially validated with MRS. Impact: The metabolic insights that CEST-MRI offers to HIV immunological care may aid in the development of increasingly effective ART drugs, such as long-acting injectables. Increased efficacy of ART will allow for increased quality of life for people living with HIV. |
| 4452.
 | 127 | Renal Metabolic CEST-MRI Based on Golden-Angle Radial Sampling Under Free Breathing Quan Tao1,2,3, Zelong Chen4, Zhigang Wu5, Kan Deng6, Yizhe Zhang2,3,7, Qianqian Zhang2,3,7, Wenyan Zhang2,3,7, Ting Lin8, and Yanqiu Feng1,2,3,7
1Department of Rehabilitation Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, China, 2Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, China, 3Guangdong Provincial Engineering Laboratory for Medical Imaging and Diagnostic Technology, Guangzhou, China, 4Medical Imaging Center, Nanfang Hospital, Southern Medical University, Guangzhou, China, 5Philips Healthcare, Shenzhen, China, 6Philips Healthcare, Guangzhou, China, 7School of Biomedical Engineering, Southern Medical University, Guangzhou, China, 8Department of Radiology, Zhujiang Hospital, Southern Medical University, Guangzhou, China Keywords: CEST / APT / NOE, Kidney Motivation: Respiration motion may induce artifact in CEST image and the in-accurate quantization of CEST signal. Goal(s): We aimed to develop clinical motion-insensitive CEST imaging of kidney. Approach: Here, we used turbo filed echo (TFE) based on golden-angle radial sampling to readout renal CEST image under free breathing of three normal volunteers and also evaluated its effectiveness for motion artifact suppression. Results: The renal Z-spectrum is float and there is no motion artifact in CEST images. This motion in-sensitive sequence showed high repeatability for renal CEST imaging. Impact: It
may provide a motion in-sensitive CEST imaging sequence for renal imaging in
clinical nephropathy patients under free breathing, and improve the accuracy of
injury detection. |