Hongyun Li¹, Zhenxiong Wang², Zhongping Zhang³, and Jie Fang^1
1Nantong University, Nantong, China, ²Guangzhou First People's Hospital, Guangzhou, China, ³Philips Healthcare China, Guangzhou, China

Gd2O3 hollow nanospheres (HNS) with tuneable size and shell thickness was prepared. The thinnest shell of 30 nm Gd2O3 HNS achieved is 2.9 nm. This ultra-thin Gd2O3 HNS show effective T1 relaxivity in MRI with the highest r1 value of 3.77 mM-1s-1. Furthermore, the Gd2O3 HNS indicate strong chemical and physical stability which will minimize the toxicity caused by released free Gd3+ ions. The monodispersed and tuneable particle size will also facilitate the particle surface modification and blood circulation time design in bio-applications.

Dayong Jin¹, Xin Li¹, Yue Qin¹, Yinhu Zhu¹, Liyao Liu¹, Yifan Qian¹, Juan Tian¹, and Shaoyu Wang^2
1Xi'an Daxing Hospital, Xi'an, China, ²Siemens Healthineers, Ltd., Xi'an, China

This study compared the image quality of MRCP before and after contrast agent injection on a 3T MRI scanner using the same respiratory-triggered 3D-SPACE sequence. Our results showed that enhancement of contrast-to-noise ratio (CNR) and background suppression will make the contour of pancreaticobiliary system more clear, which indirectly improves the imaging effect of MRCP. We performed MRCP scanning during the delayed waiting period for enhanced scans, which shortens the overall scan time for such patients. In summary, respiratory-triggered 3D-SPACE MRCP imaging with enhanced contrast injection significantly improved the imaging quality of the pancreaticobiliary duct and shorten the overall acquisition time. It is worthy of promotion and application in clinical practice. 

Lesheng Huang¹, Hong yi Li¹, Jun Chen¹, Weiyin Vivian Liu ², Kai li Cai¹, Jing hua Jiang¹, Wan chun Zhang¹, Jia hui Tang¹, Guang jun Tian³, Tao He¹, Kai lian Yang¹, Meng Hu¹, Dong Zhang³, and Dan Li^3
1Radiology, Guangdong Hospital of Traditional Chinese Medicine, Zhuhai, Zhu Hai, China, ²MR Research, GE Healthcare, Beijing, China, Beijing, China, ³Hepatology, Guangdong Hospital of Traditional Chinese Medicine, Zhuhai, Zhu Hai, China

To long-term track patients with liver disease is often carried out in clinics. It is also noted that nonspecific contrast agents change the relaxation time of tissue components, but few studies focus on the strong or weak FF alteration reflected by IDEAL-IQ derived measurements acquired before and after the contrast injection. In our study, we discovered significantly altered T1 values and fat fraction but not R2* even after the non-specific contrast agent achieved balanced condition at 3 minutes later of post-injection. Therefore, the liver non-specific contrast agent had an impact on the fat fraction measurements computed by IDEAL-IQ, and the utility of IDEAL-IQ should be performed before the injection of contrast agents to ensure the accuracy of fat fraction.

Keisuke Nitta¹, Chiaki Tominaga¹, Koji Matsumoto¹, Hajime Yokota², Yoshitada Masuda¹, and Takashi Uno^2
1Department of Radiology, Chiba University Hospital, Chiba, Japan, ²Diagnostic Radiology and Radiation Oncology, Graduate School of Medicine, Chiba, Japan

Patient anxiety could be a risk factor for adverse reaction to contrast agents. We hypothesized that a patient-friendly audiovisual system in the MR scanner room had a relaxing effect on patients and the occurrence of adverse reactions. As a result, the patient-friendly audiovisual system compared to the standard system reduced contrast agents reaction. Thus, this system may reduce adverse reaction in patients by providing a more patient-centered MRI examination environment.

Takayuki Sakai¹, Hajime Yokota², Masami Yoneyama³, Gabriele M Beck⁴, Daichi Murayama¹, Shigehiro Ochi¹, Tosiaki Miyati⁵, and Atsuya Watanabe^6,7
1Radiology, Eastern Chiba Medical Center, Chiba, Japan, ²Diagnostic Radiology and Radiation Oncology, Graduate School of Medicine, Chiba University, Chiba, Japan, ³Philips Japan, Tokyo, Japan, ⁴Philips Healthcare, Best, Netherlands, ⁵Faculty of Health Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, Japan, ⁶Orthopaedic Surgery, Eastern Chiba Medical Center, Chiba, Japan, ⁷General Medical Services, Graduate School of Medicine, Chiba University Graduate School of Medicine, Chiba, Japan

Shorter examination time might miss the appropriate timing for depicting the “delayed-enhanced” lesions, such as brain metastasis and multiple sclerosis plaques. We focused on the CENTRA-PLUS view-ordering framework and tried to modify the k-space profile ordering to enable completely timing-reversed (SLUP-ARTNEC). The purpose of this study is to demonstrate the feasibility of SULP-ARTNEC in the patients with brain metastasis. SLUP-ARTNEC is the unique approach in the post compressed sensing era that can improve the image contrast between delayed-enhanced brain metastasis lesions and background tissues in the contrast-enhanced studies without having the extra-waiting time, resulting in maintain the shorter examination time.

Adan Jafet Garcia¹, Shao Ying Huang^2,3, Nevrez Imamoglu⁴, and Wenwei Yu^1,5
1Medical systems, Chiba University, Chiba, Japan, ²Department of Surgery, National University of Singapore, Singapore, Singapore, ³Engineering Product Development, Singapore University of Technology and Design, Singapore, Singapore, ⁴Digital Architecture Research Center, National Institute of Advanced Industrial Science and Technology, Tokyo, Japan, ⁵Center for Frontier Medical Engineering, Chiba University, Chiba, Japan

Magnetic Resonance Electrical Property Tomography (MREPT) could provide important contrast for non-calcified tumors. However, MREPT relies on numerical differentiation, which is noise sensitive and prone to artifacts near boundaries.

In this work, physics-informed neural networks (PINN), NN empowered automatic differentiation is proposed to improve MREPT by mitigating artifacts and reducing noise sensitivity. Instead of calculating partial derivatives numerically, is obtained by backpropagation through PINNs.

For clinical MREPT, reduction of ground-truth information to guide PINNs was investigated. Results show that above 25% collocation points, reconstruction can be made at 100 SNR. PINNs enable noise-robust and artifact-free MREPT from less ground-truth information.

Xue Ren¹, Jiazheng Wang², Liangjie Lin², Lihua Chen¹, Qingwei Song¹, Renwang Pu¹, Ying Zhao¹, Tao Lin¹, Qihao Xu¹, and Ailian Liu^1
1Department of Radiology, the First Affiliated Hospital of Dalian Medical University, Dalian, China, ²Philips Healthcare, Beijing, China

The quantitative MR dynamic contrast-enhanced (DCE) and mDIXON-Quant imaging were used in this study for differentiation between benign and malignant liver lesions. The combination of DCE and mDIXON-Quant showed significantly improved diagnostic efficacy between benign liver tumors and primary malignant tumors, as well as between primary and secondary malignant tumors.

Yang Gao¹, Zhuang Xiong ¹, Amir Fazlollahi², Peter J Nestor², Viktor Vegh³, G. Bruce Pike⁴, Stuart Crozier¹, Feng Liu¹, and Hongfu Sun^1
1School of ITEE, University of Queensland, Brisbane, Australia, ²Queensland Brain Institute, University of Queensland, Brisbane, Australia, ³Centre for Advanced Imaging, University of Queensland, Brisbane, Australia, ⁴Departments of Radiology and Clinical Neurosciences, University of Calgary, Calgray, AB, Canada

Deep learning frameworks are emerging methods for solving QSM problems these days. However, most previous deep neural networks designed for QSM requires phase unwrapping and background field removal preprocessing procedures. This work presents a novel end-to-end network, namely Lap-Unet, for instant QSM and tissue field mapping from the raw phase in a single run. Comparative results find that the proposed method resulted in more accurate and robust reconstructions than previously established single- and multi-step methods, particularly for QSM of intracranial hemorrhages, which has been challenging due to fast signal decays.

Ziyi Pan¹, Jianxiong Hu², Hai Luo², Simin Liu¹, Sisi Li¹, Ziyue Wu², and Hua Guo^1
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China, ²Marvel Stone Healthcare Co., Ltd., Wuxi, China

Low field MR-guided thermotherapy can provide some key advantages over the high-field alternative, including reduced cost, decreased susceptibility artifacts, and improved safety of interventional devices. However, both the accuracy and the speed of PRF temperature measurement suffer at the low field due to the reduced SNR, limited receive channels, and declined temperature-induced phase changes, making it unreliable for clinical MRgLITT treatments. In this study, we demonstrate that the multi-echo thermometry together with the view-sharing acceleration can be utilized to achieve high-quality PRF thermometry at 0.5T with satisfactory temperature measurement precision and temporal resolution.  

Changxiang Wang¹, Yongsheng Ao², Lihua Qiu², Lan Mu³, Junhui Huang¹, Shuheng Zhang⁴, Shimin Yang⁴, Xin Liu¹, Hairong Zheng¹, and Na Zhang^1
1Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China, ²Department of Radiology, The Second People’s Hospital of Yibin, Yibin, China, ³Department of Radiology,Pidu District People's Hospital, Chengdu, China, ⁴United Imaging Healthcare, Shanghai, China

Diffusion-Weighted Imaging (DWI) and T2-weighted imaging (T2WI) are two necessary sequences in breast MRI which of great significance for breast cancer. They are usually performed before contrast agent injection in the conventional breast MRI protocol. Recently, some studies have proposed simplified and fast breast scanning protocol, of which, DWI and T2WI are performed after contrast agent injection. This study evaluated the clinical value of DWI and T2WI after contrast agent in the diagnosis of breast cancer. The results showed that contrast injection has no effect on DWI, but it can improve the signal-to-noise ratio and contrast-to-noise ratio of T2WI.