Clinical significance of visually equivocal amyloid PET findings from the Alzheimer’s Disease Neuroimaging Initiative cohort

Oh, Minyoung,Seo, Minjung,Oh, Sun Young,Kim, Heeyoung,Choi, Byung Wook,Oh, Jungsu S.,Kim, Jae Seung Wolters Kluwer Health | Lippincott Williams Wilkin 2018 NEUROREPORT - Vol.29 No.7

<P>To evaluate the clinical and imaging characteristics of patients with visually equivocal amyloid PET images, patients from the Alzheimer's Disease Neuroimaging Initiative cohort who had fluorine-18-florbetapir PET scans both at baseline and 24 months were selected. Five nuclear medicine physicians visually assessed the PET images and classified them as either positive or negative. Images not reaching a majority agreement were classified as equivocal. Among a total of 379 patients, the number of patients in each fluorine-18-florbetapir PET negative/equivocal/positive categories was 218 (57.5%), 32 (8.4%), and 129 (34.0%). Eight to 9% of patients with normal cognition (N=12/141), mild cognitive impairment (N=20/214), and no Alzheimer's disease (N=0/24) showed equivocal PET finding for each. In negative/equivocal/positive groups, positive cerebrospinal fluid A(1-42) was observed in 25.7, 81.5, and 98.3%, respectively. Baseline standardized uptake value ratios of fluorine-18-florbetapir PET were 0.75 +/- 0.05, 0.86 +/- 0.09, and 1.01 +/- 0.09, respectively [F(2,376)=603.547; P<0.001]. After 24 months of follow-up, the standardized uptake value ratios increased by 0.81 +/- 2.62, 2.81 +/- 2.90, and 2.17 +/- 3.66%, respectively [F(2,376)=7.905, P<0.05 vs. the negative group]. Among mild cognitive impairment patients, the equivocal group showed a more rapid decline in glucose metabolism than the negative group [5.52 +/- 5.36 vs. 0.67 +/- 4.45; F(2,122)=9.028, P<0.01]. 8.4% of the patients in this study showed a visually equivocal result of amyloid PET. These patients showed a moderate amount of amyloid accumulation and a rapid rate of accumulation.</P>

Nuclear Medicine Physics: Review of Advanced Technology

Oh, Jungsu S. Korean Society of Medical Physics 2020 의학물리 Vol.31 No.3

This review aims to provide a brief, comprehensive overview of advanced technologies of nuclear medicine physics, with a focus on recent developments from both hardware and software perspectives. Developments in image acquisition/reconstruction, especially the time-of-flight and point spread function, have potential advantages in the image signal-to-noise ratio and spatial resolution. Modern detector materials and devices (including lutetium oxyorthosilicate, cadmium zinc tellurium, and silicon photomultiplier) as well as modern nuclear medicine imaging systems (including positron emission tomography [PET]/computerized tomography [CT], whole-body PET, PET/magnetic resonance [MR], and digital PET) enable not only high-quality digital image acquisition, but also subsequent image processing, including image reconstruction and post-reconstruction methods. Moreover, theranostics in nuclear medicine extend the usefulness of nuclear medicine physics far more than quantitative image-based diagnosis, playing a key role in personalized/precision medicine by raising the importance of internal radiation dosimetry in nuclear medicine. Now that deep-learning-based image processing can be incorporated in nuclear medicine image acquisition/processing, the aforementioned fields of nuclear medicine physics face the new era of Industry 4.0. Ongoing technological developments in nuclear medicine physics are leading to enhanced image quality and decreased radiation exposure as well as quantitative and personalized healthcare.

Thalamo-frontal white matter alterations in chronic schizophrenia : A quantitative diffusion tractography study

Oh, Jungsu S.,Marek, K,Gudrun, R,Sylvain, B,Levitt, James J.,McCarley, Robert W.,Carl-Fredrik, W,Shenton, Martha E. Wiley Subscription Services, Inc., A Wiley Company 2009 Human brain mapping Vol.30 No.11

<P>Diffusion tensor imaging (DTI) and fiber tractography are useful tools for reconstructing white matter tracts (WMT) in the brain. Previous tractography studies have sought to segment reconstructed WMT into anatomical structures using several approaches, but quantification has been limited to extracting mean values of diffusion indices. Delineating WMT in schizophrenia is of particular interest because schizophrenia has been hypothesized to be a disorder of disrupted connectivity, especially between frontal and temporal regions of the brain. In this study, we aim to differentiate diffusion properties of thalamo-frontal pathways in schizophrenia from normal controls. We present a quantitative group comparison method, which combines the strengths of both tractography-based and voxel-based studies. Our algorithm extracts white matter pathways using whole brain tractography. Functionally relevant bundles are selected and parsed from the resulting set of tracts, using an internal capsule (IC) region of interest (ROI) as “source”, and different Brodmann area (BA) ROIs as “targets”. The resulting bundles are then longitudinally parameterized so that diffusion properties can be measured and compared along the WMT. Using this processing pipeline, we were able to find altered diffusion properties in male patients with chronic schizophrenia in terms of fractional anisotropy (FA) decreases and mean diffusivity (MD) increases in precise and functionally relevant locations. These findings suggest that our method can enhance the regional and functional specificity of DTI group studies, thus improving our understanding of brain function. Hum Brain Mapp, 2009. © 2009 Wiley-Liss, Inc.</P>

Reduced fronto‐callosal fiber integrity in unmedicated OCD patients: A diffusion tractography study

Oh, Jungsu S.,Jang, Joon Hwan,Jung, Wi Hoon,Kang, Do‐,Hyung,Choi, Jung‐,Seok,Choi, Chi‐,Hoon,Kubicki, Marek,Shenton, Martha E.,Kwon, Jun Soo Wiley Subscription Services, Inc., A Wiley Company 2012 Human brain mapping Vol.33 No.10

<P><B>Abstract</B></P><P>It is widely accepted that abnormalities in the frontal area of the brain underpin the pathophysiology of obsessive‐compulsive disorder (OCD). Fundamental to this investigation is the delineation of frontal white matter tracts including dorsal and ventral frontal projections of interhemispheric connections. While previous investigations of OCD have examined the dorsal and ventral frontal regions, the corresponding callosal connections have not been investigated, despite their importance. We recruited twenty patients with OCD (15 drug‐naïve and 5 currently unmedicated) and demographically similar healthy controls, and conducted fiber tractography and <I>post hoc</I> quantitative analysis using diffusion tensor imaging. We extracted fractional anisotropy (FA) of the fronto‐callosal fibers along the entire length of the tract. Function‐specific [by the Brodmann area region‐of‐interest (ROI) approach] and region‐specific (by the length‐parameterization approach) tracts were defined. In addition, we devised a new index of dorsal‐ventral imbalance (DVII) of fiber integrity. Significant FA decreases were observed in orbitofrontal and dorsolateral prefrontal projections of the corpus callosum (<I>P</I> < 0.05, false discovery rate‐corrected) with higher function/region sensitivity than voxel‐based or ROI‐based approaches. Importantly, OCD patients also exhibited significantly higher ventral‐greater‐than‐dorsal asymmetry of FA values than normal controls (<I>P</I> < 0.05, FDR‐corrected). This study is the first to investigate fiber integrity in the dorsal/ventral frontal parts of the callosal tractography in unmedicated OCD patients. Using a more quantitative method in terms of functional and regional specificity than previous studies, we report abnormalities in interhemispheric connectivity of both dorsal and ventral networks in the pathophysiology of OCD. Hum Brain Mapp 33:2441–2452, 2012. © 2011 Wiley Periodicals, Inc.</P>

Software development for ACR-approved phantom-based nuclear medicine tomographic image quality control with cross-platform compatibility

Oh, Jungsu S.,Choi, Jae Min,Nam, Ki Pyo,Chae, Sun Young,Ryu, Jin-Sook,Moon, Dae Hyuk,Kim, Jae Seung Korean Physical Society 2015 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.67 No.2

Additional Value of Early-Phase 18F-FP-CIT PET Image for Differential Diagnosis of Atypical Parkinsonism

Jin, Soyoung,Oh, Minyoung,Oh, Seung Jun,Oh, Jungsu S.,Lee, Sang Ju,Chung, Sun Ju,Kim, Jae Seung Lippincott 2017 Clinical nuclear medicine Vol.42 No.2

<P>Conclusion: F-18-FP-CIT PETs with the first 10 minutes could be useful for the differential diagnosis of atypical Parkinson disorder by providing complementary FDG-like information to the dopamine transporter binding on late-phase FP-CIT images.</P>

Neural substrates of cognitive reserve in Alzheimer's disease spectrum and normal aging

Lee, Dong Hyuk,Lee, Peter,Seo, Sang Won,Roh, Jee Hoon,Oh, Minyoung,Oh, Jungsu S.,Oh, Seung Jun,Kim, Jae Seung,Jeong, Yong ACADEMIC PRESS 2019 NeuroImage Vol. No.

<P><B>Abstract</B></P> <P>The concept of cognitive reserve (CR) originated from discrepancies between the degree of brain pathology and the severity of clinical manifestations. CR has been characterized through CR proxies, such as education and occupation complexity; however, such approaches have inherent limitations. Although several methods have been developed to overcome these limitations, they fail to reflect the entire Alzheimer's disease (AD) pathology. Meanwhile, graph theory analysis, one of most powerful and flexible approaches, have established remarkable network properties of the brain. The functional and structural brain networks are damaged in neurodegenerative diseases. Therefore, network analysis has been applied to clarify the characteristics of the disease or give insight. Here, using multimodal neuroimaging, we propose an intuitive model to estimate CR based on its original definition, and explore the neural substrates of CR from the perspective of networks and functional connectivity. A total of 87 subjects (21 AD, 32 mild cognitive impairment, and 34 normal aging) underwent tau and amyloid PET, 3D T1-weighted MR, and resting-state fMRI. We hypothesized CR as a residual of actual cognitive performance and expected performance to be related to quantitative factors, such as AD pathology, demographics, and a genetic factor. Then, we correlated this marker using education and occupation complexity as conventional CR proxies. We validated this marker by testing whether it would modulate the effect of brain pathology on memory function. To examine the neural substrates associated with CR, we performed graph analysis to investigate the association between the CR marker and network measures at different granularities in total subjects, AD spectrum and normal aging, respectively. The CR marker from our model was well associated with education and occupation complexity. More directly, the CR marker was revealed to modify the relationship between brain pathology and memory function among AD spectrum. The CR marker was correlated with the global efficiency of the entire network, nodal clustering coefficient, and local efficiency of the right middle-temporal pole. In connectivity analysis, one cluster of edges centered on right middle-temporal pole was significantly correlated with the CR marker. In subgroup analysis, the network measures of right middle-temporal pole still correlated with the CR marker among AD spectrum. However, right precentral gyrus was revealed to be associated with the CR marker in normal aging. This study demonstrates that our intuitive model using multimodal neuroimaging and network perspective adequately and comprehensively captures CR. From a network perspective, CR is associated with the capacity to process information efficiently in the brain. The right middle-temporal pole was revealed to be a pivotal neural substrate of CR in AD spectrum. These findings foster understanding of AD and will be useful to help identify individuals with vulnerability or resistance to AD pathology, and characterize patients for intervention or drug trials.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We generated an equation to quantify cognitive reserve (CR) reflecting overall AD neuropathology using multimodal neuroimaging techniques. </LI> <LI> CR was proved to modify the relationship between brain pathology and memory function in AD spectrum. </LI> <LI> CR was associated with global network efficiency and nodal clustering coefficient and local efficiency of the right middle-temporal pole. </LI> <LI> Graph parameters of right middle-temporal pole was revealed to modulate the effect of brain atrophy on cognition in AD spectrum. </LI> </UL> </P>

Development of a Gene-based Molecular Marker System for TYLCV and Late Blight Resistances inTomatoes

Jungsu Jung,Hyun Jung Kim,Munhui Kim,Je Min Lee,Chang Sik Oh,Inhwa Yeam 한국원예학회 2014 한국원예학회 학술발표요지 Vol.2014 No.10

토마토반신위조병과 토마토황화잎말림 바이러스 저항성 유전자 기반 CAPS 분자표지 개발

정정수(Jungsu Jung),이제민(Je Min Lee),오창식(Chang-Sik Oh),김현정(Hyun Jung Kim),염인화(Inhwa Yeam) 한국원예학회 2014 한국원예학회 학술발표요지 Vol.2014 No.5

Expression and Relationship of Male Reproductive ADAMs in Mouse1

Kim, Taewan,Oh, Jungsu,Woo, Jong-Min,Choi, Eunyoung,Im, Sin Hyeog,Yoo, Yung Joon,Kim, Do Han,Nishimura, Hitoshi,Cho, Chunghee Society for the Study of Reproduction 2006 BIOLOGY OF REPRODUCTION Vol.74 No.4

A number of a disintegrin and metalloprotease (ADAM) family members are expressed in mammalian male reproductive organs such as testis and epididymis. These reproductive ADAMs are divided phylogenically into three major groups: ADAMs 1, 4, 6, 20, 21, 24, 25, 26, 29, 30, and 34 (the first group); ADAMs 2, 3, 5, 27, and 32 (the second group); and ADAMs 7 and 28 (the third group). Previous mouse knockout studies indicate that ADAM1, ADAM2, and ADAM3 have intricate expressional relationships, playing critical roles in fertilization. In the present study, we analyzed processing, biochemical characteristics, localization, and expressional relationship of the previously-unexplored, second-group ADAMs (ADAM5, ADAM27, and ADAM32). We found that all of the three ADAMs are made as precursors in the testis and processed during epididymal maturation, and that ADAM5 and ADAM32, but not ADAM27, are located on the sperm surface. Using sperm from Adam2??/?? and Adam3??/?? mice, we found that, among the three ADAMs, the level of ADAM5 is modestly and severely reduced in Adam3 and Adam2 knockout sperm, respectively. Further, we analyzed ADAM7, an epididymis-derived sperm surface ADAM from the separate phylogenetic group, in the knockout sperm. We found that the level of ADAM7 is also significantly reduced in both Adam2 and Adam3-null sperm. Taken together, our results suggest a novel expressional relationship of ADAM5 and ADAM7 with ADAM2 and ADAM3, which play critical roles in fertilization.