Céline Charroud¹ and Luca Turella^1
1Center for Mind/Brain Sciences - CIMeC, Mattarello, Italy

This study investigated the subcortical structural modifications associated with motor symptoms of Parkinson Disease (PD) over time.

Fifty subjects with PD performed two MRI sessions (baseline/48months). Motor symptoms were assessed using the Unified Parkinson’s Disease Rating Scale III.

Our results showed an atrophy over time in all subcortical regions linked to the progression of PD. Furthermore, a reduced volume in thalamus and an increased volume in pallidum were associated with a decline in motor skills, consistent with the model of thalamo-cortical functional loops. Finally, we confirm that VBM and volumetry are complementary tools to assess brain degeneration in PD.

Dilek Betul Arslan¹, Hakan Ibrahim Gurvit², Ozan Genc¹, Sevim Cengiz¹, Ani Kicik^3,4, Kardelen Eryurek^4,5, Emel Erdogdu^4,6, Zerrin Yildirim², Zeynep Tufekcioglu², Aziz Mufit Ulug^1,7, Basar Bilgic², Hasmet Hanagasi², Tamer Demiralp^4,8, and Esin Ozturk-Isik^1
1Biomedical Engineering, Biomedical Engineering Institution, Bogazici University, Istanbul, Turkey, ²Behavioral Neurology and Movement Disorders Unit, Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey, ³Department of Physiology, Faculty of Medicine, Demiroglu Bilim University, Istanbul, Turkey, ⁴Neuroimaging Unit, Hulusi Behcet Life Sciences Research Center, Istanbul University, Istanbul, Turkey, ⁵Department of Neuroscience, Aziz Sancar Institute of Experimental Medicine, Istanbul University, Istanbul, Turkey, ⁶Department of Psychology, Faculty of Arts and Sciences, Isik University, Istanbul, Turkey, ⁷CorTechs Labs, San Diego, CA, United States, ⁸Department of Physiology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey

The main aim of this study was to detect perfusion deficits at general executive, cognitive and visual domains of Parkinson's disease (PD) patients with mild cognitive impairment and normal cognition compared to healthy controls based on cerebral blood flow (CBF) maps obtained with arterial spin labeling MRI (ASL-MRI). CBF maps were calculated by fitting a general kinetic curve model for each pixel of ASL-MR images. A hypoperfusion pattern was observed in PD in line with general cognitive and executive dysfunction. 

Chao Zhang¹, Weiqiang Dou², and Kai Xu^1
1Department of Radiology, Xuzhou Medical University, Xuzhou, China, ²GE Healthcare,MR Research China, Beijing, China

Different functional connectivities of Basal nucleus of Meynert (BNM-FC) and the other brain regions among patients with Parkinson’s Disease (PD) accompanied and not accompanied with mild cognition impairment (PD-MCIs and PD-NCs, respectively) have been investigated in this study. A model based on Support-Vector-Machine with BNM-FC and neuropsychological results showed significantly decreased BNM-FC in the right superior parietal lobe of PD-MCIs than PD-NCs, allowing an accurate differentiation between PD-MCIs and PD-NCls. These results advanced our knowledge of the cholinergic system underpinning cognitive function in PD individuals.

Yao-Chia Shih^1,2, Bénédicte Maréchal^3,4,5, Ricardo Corredor Jerez^3,4,5, Septian Hartono^2,6, Hui-Hua Li^2,7, Isabel Hui Min Chew¹, Eng King Tan^2,6, and Ling Ling Chan^1,2
1Department of Diagnostic Radiology, Singapore General Hospital, Singapore, Singapore, ²Duke-NUS Medical School, Singapore, Singapore, ³Advanced Clinical Imaging Technology, Siemens Healthcare AG, Lausanne, Switzerland, ⁴Department of Radiology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland, ⁵LTS5, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, ⁶Department of Neurology, National Neuroscience Institute (Outram-campus), Singapore, Singapore, ⁷Health Services Research Unit, Singapore General Hospital, Singapore, Singapore

Progressive supranuclear palsy phenotypes are increasingly recognized and the Magnetic Resonance Parkinsonism Index (MRPI) useful in supporting clinical diagnosis. We examined the test-retest reliability of a landmark-based automated algorithm to derive MRPI from >2000 brain scans across different cohorts with neurodegeneration and MRI systems. We also investigated temporal changes in the MRPI derived from longitudinal scans 6–10 years apart in 53 subjects from case-control Parkinson’s disease cohorts. We found the automated MRPI fast (averaging 25s ± 2s per case) and reliable (average coefficient of variance <20%), without significant change in MRPI over time in aging and Parkinson’s disease.

xueling Liu¹, Pu-Yeh Wu², and Yuxin Li^1
1Department of Radiology, Huashan hospital affiliated to Fudan University, Shanghai, China, ²GE Healthcare, Beijing, China, Shang Hai, China

In this study, we investigated alterations of iron and NM in EPD, and correlations between them and VMAT2 binding in nigrostriatal system. Our results suggested that changes of neuromelanin and susceptibility on QSM images could quantitatively reflect the pathology of EPD and could be used as imaging biomarkers for diagnosing of EPD. The SUR measured by 18F-DTBZ images could reflect the lateralization in EPD patients. NM volume could reflect the striatal dopaminergic function, and both CR value and SUR could reflect the severity of motor impairment in EPD, which are expected to be used for monitoring the progression of EPD.

Yan Bai^1,2, Rushi Chen^1,2, Wei Wei^1,2, Rui Zhang^1,2, Zhun Huang^2,3, Xianchang Zhang⁴, Mathias Nittka⁵, Gregor Koerzdoerfer⁵, and Meiyun Wang^1,2
1Department of Radiology, Zhengzhou University People’s Hospital & Henan Provincial People’s Hospital, Academy of Medical Sciences., Zhengzhou, China, ²Henan Key Laboratory for Medical Imaging of Neurological Diseases, Zhengzhou, Henan, China, ZhengZhou, China, ³Department of Radiology, Henan University People’s Hospital & Henan Provincial People’s Hospital, School of Basic Medicine., Zhengzhou, China, ⁴MR Collaboration, Siemens Healthcare Ltd., Beijing, China, BeiJing, China, ⁵MR Pre-development, Siemens Healthcare GmbH, Erlangen, Germany, Erlangen, Germany

Conventional magnetic resonance imaging cannot reliably differentiate Parkinson’s disease (PD) from essential tremors (ET). Magnetic resonance fingerprinting (MRF) can simultaneously acquire T1 and T2 relaxometry. This study utilized MRF to obtain T1 and T2 values in substantia nigra (SN) of patients with tremor-dominant PD and ET. The T1 values of SN were significantly higher in patients with tremor-dominant PD than those with ET, whereas the T2 values showed no significant differences between groups. The findings suggest that MRF T1 mapping of the SN can potentially differentiate tremor-dominant PD from ET

Oren Solomon¹, Tara Palnitkar^1,2, Rémi Patriat¹, Henry Braun¹, Joshua Aman², Michael C Park^2,3, Guillermo Sapiro⁴, Jerrold Vitek², and Noam Harel^1,3
1Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN, United States, ²Department of Neurology, University of Minnesota, Minneapolis, MN, United States, ³Department of Neurosurgery, University of Minnesota, Minneapolis, MN, United States, ⁴Department of Electrical and Computer Engineering, Department of Biomedical Engineering, Department of Computer Science, Department of Mathematics, Duke University, Durham, NC, United States

Deep brain stimulation (DBS) surgery has been shown to improve the quality of life for patients with various motor dysfunctions. The success of DBS is directly related to the proper placement of the electrodes, which requires accurate detection and identification of the relevant target structures. We present a deep-learning based automatic, robust and accurate segmentation technique from 7 Tesla MRI acquisitions of subcortical structures for DBS surgery planning and post-operative electrode localization. DBS targets and related structures include the subthalamic nucleus, substantia nigra, red nucleus and the internal and external compartments of the globus pallidus.

Dmytro Pylypenko¹, Yuhui Xiong¹, Lanxin Ji¹, Le He¹, Yu Ma², and Hua Guo^1
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University, Beijing, China, ²Department of Neurosurgery, Tsinghua University Yuquan Hospital, Beijing, China

This study aimed to perform an evaluation of the vascular geometry in PD patients vs. healthy control group to quantify the structural changes in the cerebral vasculature by analyzing SWI MRA data. Findings show,  that the PD’s vasculature network was found to have a higher tortuosity, fractality, and branching, yet lower volume and total length as well as smaller average diameter. It is also important to state that aging has a great impact on vascular impairment in PD patients.

Yong Zhang¹, Chang-Peng Wang², Jian Wang², Li-Rong Jin², and Bing Wu^3
1GE Healthcare, Shanghai, China, ²Zhongshan Hospital, Shanghai, China, ³GE Healthcare, Beijing, China

We aimed to investigate the patterns of cerebral perfusion changes in early drug-naive PD patients with mild cognitive impairment (PD-MCI). Voxel-wise cerebral blood flow (CBF) were compared among PD-MCI patients, PD patients with normal cognition (PD-NC) and healthy controls. Increased CBF was detected in the right anterior cingulate cortex in the PD-MCI group as compared to the controls, as well as higher perfusion in the right middle frontal gyrus and superior frontal gyrus relative to PD-NC. Cerebral hyper-perfusion in frontal lobe might be associated with cognitive decline in early de novo PD.

Yu Shen¹, Xianchang Zhang², Yan Bai¹, Yaping Wu¹, Ewart Mark Haacke³, Bo Wu⁴, Yongsheng Chen⁴, Rui Zhang¹, Rushi Chen¹, Wei Wei¹, and Meiyun Wang^1
1Department of Medical Imaging, Henan Provincial People’s Hospital & Zhengzhou University, Zhengzhou, China, ²MR Collaboration, Siemens Healthcare Ltd. Beijing China, Beijing, China, ³Wayne State University, Detroit, MI, United States, ⁴Shanghai Zhuyan Medical Technology Company, Shanghai, China

Scanning patients with Parkinson’s disease (PD) is challenging because of tremors. Strategically acquired gradient echo (STAGE) imaging can acquire seven quantitative images relatively quickly. This method could provide comprehensive evaluations of cerebral alterations in PD patients while reducing motion artifacts. This study compared T1, T2*, R2*, and susceptibility-weighted imaging mapping (SWIM) acquired with STAGE imaging between 15 PD patients and 15 healthy controls (HC). Significant differences were found for the T1 and T2* values in several brain areas between PD and HC, suggesting that STAGE imaging is a convenient and powerful tool to investigate PD. 

Jae-Hyuk Shim¹ and Hyeon-Man Baek^1
1Gachon University, Incheon, Korea, Republic of

The MNI PD25 subcortical atlas, which consists of key structures involved in Parkinson’s disease, was automatically segmented on each 3T control and Parkinson’s disease diffusion data obtained from the Parkinson’s disease Progression Marker Initiative (PPMI) database. Diffusion measures such as FA, AD, RD, MD and QA were obtained from each segmented ROI and interconnectivity for comparison between controls and Parkinson’s disease patients to observe for significant biomarkers that occur in basal ganglia due to Parkinson’s disease.

Ting-Chieh Chen¹, Yu-Chun Lo², Yi-Chen Lin¹, Ssu-Ju Li¹, Ting-Chun Lin¹, Ching-Wen Chang¹, Yao-Wen Liang¹, Hsiao-Chi Chuang³, and You-Yin Chen^1,2
1Biomedical Engineering, National Yang-Ming University, Taipei, Taiwan, ²Ph.D. Program for Neural Regenerative Medicine, Taipei Medical University, Taipei, Taiwan, ³School of Respiratory Therapy, College of Medicine, Taipei Medical University, Taipei, Taiwan

Exposure to air pollution was demonstrated to be correlated with the neurodegenerative disease showing the cognitive deficits, but the impacts on motor function has yet to be investigated. The motor behavioral test and diffusion magnetic resonance imaging (MRI) tractography analysis were applied to the traffic-related particulate matter (PM)-exposed models in this study. We found the decline in motor function and the destruction of the microstructure after exposed to traffic-related PM for 3 months, in which the structural alterations of motor control circuit were similar to the characteristic of the Parkinson's disease (PD).

Wanyao Li¹, Yanwei Miao¹, Bingbing Gao¹, Yangyingqiu Liu¹, Ailian Liu¹, and Qingwei Song^1
1First Affiliated Hospital of Dalian Medical University, Dalian, China

Type 2 diabetes melitus(T2DM) is associated with worse motor imbalance and cognitive decline in Parkinson’s disease.Abnormal cerebral iron deposition occur in extrapyramidal system in PD patients. However, whether the microscopic iron deposition will increase further in Parkinson’s patients with T2DM remains unknown. In this study, the iron deposition in extrapyramidal system measured QSM was compared between Parkinson's patients with T2DM (PDDM) and Parkinson's patients without T2DM (PDND).The increased magnetic sensitivity values (MSV) were found in most brain gray matter nucleus,especially for the left globus pallidus(GP) and bilateral substantia nigra(SN),in PDDM group rather than in PDND group.

Christina Andica¹, Koji Kamagata¹, Masahiro Abe¹, Wataru Uchida^1,2, Yuya Saito¹, Hayato Nozaki^1,2, Kaito Takabayashi¹, Masaaki Hori³, and Shigeki Aoki^1
1Department of Radiology, Juntendo University Graduate School of Medicine, Tokyo, Japan, ²Department of Radiological Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, Tokyo, Japan, ³Department of Radiology, Toho University Omori Medical Center, Tokyo, Japan

Neuropathological mechanisms of Parkinson’s disease with GBA1 mutations (GBA-PD) are still unclear. We evaluated the white and gray matter of patients with early-stage GBA-PD using free water (FW) imaging. Patients with GBA-PD showed higher FW-corrected fractional anisotropy and lower FW-corrected mean diffusivity in the anterior thalamic radiation, forceps minor, and uncinate fasciculus, reflecting compensatory reorganization of neural circuits. Meanwhile, neuroinflammation (indexed by higher FW) was detected in the substantia nigra pars compacta (SNpc; Braak stage III), temporal mesocortex (Braak stage IV), forceps major, and cingulum cingulate gyrus. Furthermore, FW in the SNpc was positively correlated with the motor assessment scale.

Giacomo Tomezzoli^1,2, Lisa Novello², Francesca Saviola², Stefano Tambalo², Beatrice Federica Luciani², Enrica Pierotti², Céline Charroud ², Alessandro Gober², Francesca Giacomoni², Pamela Narduzzi², Claudia Meli², Marika Falla², Alessandra Dodich², Luca Turella², Costanza Papagno², and Jorge Jovicich^2
1DiPSCo, Department of Psychology and Cognitive Science, University of Trento, Rovereto, Italy, ²CIMeC, Center for Mind/Brain Sciences, University of Trento, Rovereto, Italy

Executive functions (EFs) play a crucial role for intact cognitive functioning, and their decline in Parkinson’s Disease (PD) patients is associated with decreased quality of life. We investigated the relationship between tractography-derived nodal properties in 8 brain regions involved in cognitive sub-components of executive control and EFs performance. We found preliminary evidence that graph-theory-derived nodal properties reveal associations with executive scores. As part of an ongoing longitudinal project, this initial evidence suggests that nodal metrics might be useful for investigating relationships between structural-connectivity properties and cognitive profiles in Parkinson’s disease.

Alba Segura Amil^1,2 and T. A. Khoa Nguyen^1,2
1Department of Neurosurgery, Inselspital, University Hospital Bern, Bern, Switzerland, ²ARTORG Center for Biomedical Engineering Research, University of Bern, Bern, Switzerland

Deep brain stimulation in the subthalamic nucleus is an effective treatment in advanced Parkinson’s disease. The aim of the current study was to determine an activation threshold of the hyperdirect pathway that results in the control of motor symptoms while avoiding the appearance of side effects. Patient-specific whole brain tractograpy, DBS leads reconstruction, and generation of volumes of tissue activated were performed in 9 subjects. The effect threshold was at 20% of hyperdirect pathway activation, while the side effect threshold was at 2% of corticospinal tract activation. 

Bingxue Cheng¹, Chenfei Ye², and Ting Ma^1,2,3
1Department of Information and Electronics, Harbin Institute of Technology at Shenzhen, GuangDong Province, China, ²Peng Cheng laboratory, Guangdong Province, China, ³National Clinical Research Center for Geriatric Disorders, Beijing, China

Our study integrated a high angular resolution diffusion imaging (HARDI) and Quantitative susceptibility mapping (QSM) to clarify whether the disease-specific patterns of the associated between iron deposits and the progress of PD are affected by the structural network. In brain sturctural network of PD, we observed that the increased small-worldness and decreased rich-club coefficients significantly mediate the association between the mean QSM value in left putamen and H&Y scale by using the causal mediation analysis.

Junlan Zhu¹, Guanxun Cheng¹, Qiaoling Zeng¹, Chao Lai¹, Jiao Li¹, and Shuwen Dong^1
1Department of Medical Imaging, Peking University Shenzhen Hospital, Shenzhen, China

By applying group information guided independent component analysis to fMRI data, the dFNCs of each subject were estimated using a sliding window method and k-means clustering. Four dynamic functional states were identified. Interestingly, our study found that dwell time in State I was positively correlated with resting tremor scors in TD-PDs dFNC strength between BG and vSMN in State3 had significant positive correlation with MDS-UPDRS-III score in PD patients. Our study indicates that tremor in Parkinson’s disease is characterized by altered dFNC strength and temporal properties in dynamic connectivity, which provides a new insight into the pathological of Parkinsonian tremor.

Silvia Basaia¹, Federica Agosta^1,2,3, Alessandro Francia¹, Camilla Cividini^1,3, Tanja Stojkovic⁴, Iva Stankovic⁴, Rosita Di Micco¹, Luigi Albano¹, Elisabetta Sarasso¹, Noemi Piramide^1,3, Vladana Markovic⁴, Elka Stefanova⁴, Vladimir S. Kostic⁴, and Massimo Filippi^1,2,3,5,6
1Neuroimaging Research Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy, ²Neurology Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy, ³Vita-Salute San Raffaele University, Milan, Italy, ⁴Clinic of Neurology, Faculty of Medicine, University of Belgrade, Belgrade, Italy, ⁵Neurorehabilitation Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy, ⁶Neurophysiology Service, IRCCS San Raffaele Scientific Institute, Milan, Italy

We investigated the functional neural organization of the motor cerebro-cerebellar system in Parkinson’s disease (PD) patients with tremor-dominant (TD) or postural instability and gait disorder (PIGD) variant. A seed-cerebellar region (lobule VI of cerebellum) was defined based on motor task-based functional MRI in healthy controls. Functional connectivity was found to be disrupted in both PD subgroups between cerebellum, thalamus and default-mode regions. We identified different localization of functional over‐connectivity, PD-PIGD within inferior frontal gyrus and insula, while PD-TD in orbitofrontal gyrus. This study might provide novel insight into the underlying pathophysiological mechanism in PD subtypes.

Yan Li¹, Yu Liu¹, Naying He¹, Chencheng Zhang², Yijie Lai², Hongyang Li², Qing Li³, Caixia Fu⁴, Fuhua Yan¹, and Ewart Mark Haacke^1,5
1Department of Radiology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China, ²Department of Neurosurgery, Center for Functional Neurosurgery, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China, ³MR Collaborations, Siemens Healthcare Ltd., Shanghai, China, ⁴MR Application Development, Siemens Shenzhen Magnetic Resonance Ltd., Shenzhen, China, ⁵Department of Radiology, Wayne State University, Detroit, MI, United States

Preliminary evidence supports the safety of diffusion weighted tractography in postoperative patients with deep brain stimulation. Here we further test the feasibility in both DBS-on and DBS-off status. Both DBS ON and OFF diffusion weighted imaging are safe and the tractography results are significantly comparable. Furthermore, we found that the nigrostriatal pathway's deterministic tractography is feasible. Our results highlight that DBS ON DTI is particularly fitting for those patients who cannot control their disease symptoms without stimulation but need MRI.