• Journal of the Korean Society of Radiology
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• v.85 no.3
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• pp.607-617
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• 2024

Purpose Recent studies have demonstrated the usefulness of diffusion-weighted MR neurography (DW MRN) for assessing nerve roots. This study aimed to evaluate the utility of DW MRN with a unidirectional motion-probing gradient (MPG) for the lumbar nerve roots at 1.5T MR. Materials and Methods Sixty-four lumbar spine MRI scans with DW MRN using anteroposterior unidirectional MPG were retrospectively analyzed. Any changes in the 512 lumbar spinal nerve roots from L3 to S1 were evaluated using T2-weighted imaging (T2WI), contrast-enhanced T1-weighted imaging (CE T1WI), and DW MRN, with agreement and correlation analysis. Results T2WI revealed compression of 78 nerve roots, and CE T1WI revealed 52 instances of nerve root enhancement. Sixty-seven nerve roots showed swelling and hyperintensity on DW MRN. A total of 42 nerve roots showed changes in the CE T1WI and DW MRN sequences. Moderate to substantial agreement and moderate positive correlation were observed between DW MRN and CE T1WI, as well as DW MRN and T2WI (κ = 0.59-0.65, ρ = 0.600-0.653). Conclusion DW MRN with unidirectional anteroposterior MPG can help evaluate neuritisrelated changes in spinal nerve roots and could serve as a sequence capable of complementing or substituting gadolinium CE imaging.

• Economic and Environmental Geology
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• v.47 no.3
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• pp.227-235
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• 2014

For technology level assessment of KIGAM World Class Laboratories (WCL) candidates, bibliometric and qualitative analysis was conducted on their research papers listed on the SCIE database during 2009-2012. For the six research areas of geoscience and mineral resources, a research excellence indicator was applied using a Modified Rank Normalized Impact Factor (mrnIF), which was introduced by Heo et al. (2008) and Cho (2013). The KIGAM research department in rare metals utilization had the highest score for Impact Factor (IF) per paper in 2012 but the groundwater department or the exploration geophysics department came first based on the position and the mrnIF. Applying the mrnIF, the KIGAM research department in groundwater achieved excellent results in 2009 and 2011 and the urban mine department or exploration geophysics department came first place in other years. In the groundwater area, the percentage of research papers over 80 or 90 mrnIF, using Cho (2013)'s research excellence index, was the highest in 2011. The Cho (2013)'s excellent research indicator, 20%, the ratio of over 90 mrnIF was matched in the urban mining area for the whole research period, 2009-2012, and in the groundwater area for several years except 2010. Qualitative analysis of research papers can show the technology level of research departments. KIGAM World Class Laboratories (WCL) candidates should focus on increasing the quality and the quantity of their research papers.

• Journal of Korean Neurosurgical Society
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• v.30 no.9
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• pp.1120-1126
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• 2001

Objective : The development of magnetic resonance neurography(MRN) has made it possible to produce highresolution images of peripheral nerves themselves, as well as associated intraneural and extraneural lesions. We evaluated the clinical application and utility of high-resolution MRN techniques for the diagnosis and treatment of a variety of peripheral nerve disorder(PND)s. Material and Method : MRN images were obtained using T1-weighted spin echo, T2-weighted fast spin echo with fat suppression, and short tau inversion recovery(STIR) fast spin-echo pulse sequences. Fifteen patients were studied, three with brachial plexus tumors, five with chronic entrapment syndromes, and seven with traumatic peripheral lesions. Ten patients underwent surgery. Results : In MRN with STIR sequences of axial and coronal imagings, signals of the peripheral nerves with various lesions were detected as fairly bright signals and were discerned from signals of the uninvolved nerves. Increased signal with proximal swelling and distal flattening of the median nerve were seen in all patients of carpal tunnel syndrome. Among the eight patients with brachial plexus injury or tumors, T2-weighted MRN showed increased signal intensity in involved roots in five, enhanced mass lesions in three, and traumatic pseudomeningocele in three. Other associated MRI findings were adjacent bony signal change, neuroma, root adhesion and denervated muscle atophy with signal change. Conclusion : MRN with high-resolution imaging can be useful in the preoperative evaluation and surgical planning in patients with peripheral nerve lesions.

• Korean Journal of Radiology
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• v.24 no.11
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• pp.1114-1130
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• 2023

Magnetic resonance neurography (MRN) is increasingly used to visualize peripheral nerves in vivo. However, the implementation and interpretation of MRN in the brachial and lumbosacral plexi are challenging because of the anatomical complexity and technical limitations. The purpose of this article was to review the clinical context of MRN, describe advanced magnetic resonance (MR) techniques for plexus imaging, and list the general categories of utility of MRN with pertinent imaging examples. The selection and optimization of MR sequences are centered on the homogeneous suppression of fat and blood vessels while enhancing the visibility of the plexus and its branches. Standard 2D fast spin-echo sequences are essential to assess morphology and signal intensity of nerves. Moreover, nerve-selective 3D isotropic images allow improved visualization of nerves and multiplanar reconstruction along their course. Diffusion-weighted and diffusion-tensor images offer microscopic and functional insights into peripheral nerves. The interpretation of MRN in the brachial and lumbosacral plexi should be based on a thorough understanding of their anatomy and pathophysiology. Anatomical landmarks assist in identifying brachial and lumbosacral plexus components of interest. Thus, understanding the varying patterns of nerve abnormalities facilitates the interpretation of aberrant findings.

• Advances in pediatric surgery
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• v.18 no.1
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• pp.12-17
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• 2012

The purpose of this study is to analyse clinical impact of specific MRI findings in liver in patients of long-term survivors after Kasai portoenterostomy (KPE). Twenty-eight patients who were underwent KPE were followed up more than 5 years. Macro-regenerative nodule (MRN) and beaded-duct dilatation (BDD) were considered as important findings in liver MRI. The association between these findings in MRI and clinical indicator, serum bilirubin level and history of cholangitis were evaluated. Sixteen patients (57.1%) were shown MRN in liver MRI. Therewere 14 patients(50%) whose MRI showed BDD. Serum total and direct bilirubin were 3.6 mg/dL and 1.8 mg/dL respectively in positive MRN group whereas 1.4 mg/dL and 0.7 mg/dL in negative MRN group (p = 0.427). Serum total and direct bilirubin level were 4.2 mg/dL and 2.1 mg/dL in patients with BDD negative group compare to 1.1 mg/dL and 0.5 mg/dL in BDD positive group (p = 0.281). The odds ratio to have cholangitis in the patient with MRN was 2.3 and 0.53 in patient with BDD in their MRI findings. MRN in liver MRI may suggest high bilirubin level and more chance to have cholangitis, but the findings of BDD may related to low bilirubin level and less change to have cholangitis.

• Journal of the Korean Society of Radiology
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• v.83 no.6
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• pp.1273-1285
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• 2022

Purpose MR neurography (MRN) is an imaging technique optimized to visualize the peripheral nerves. This review aimed to discover an optimized protocol for MRN of the lumbosacral plexus (LSP) and identify evidence for the clinical benefit of lumbosacral plexopathies. Materials and Methods We performed a systematic search of the two medical databases until September 2021. 'Magnetic resonance imaging', 'lumbosacral plexus', 'neurologic disease', or equivalent terms were used to search the literature. We extracted information on indications, MRN protocols for LSP, and clinical efficacy from 55 studies among those searched. Results MRN of the LSP is useful for displaying the distribution of peripheral nerve disease, guiding perineural injections, and assessing extraspinal causes of sciatica. Three-dimensional short-tau inversion recovery turbo spin-echo combined with vascular suppression is the mainstay of MRN. Conclusion Future work on the MRN of LSP should be directed to technical maturation and clinical validation of efficacy.

• BMB Reports
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• v.52 no.3
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• pp.208-213
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• 2019

Chemoresistance is the primary obstacle in the treatment of locally advanced and metastatic nasopharyngeal carcinoma (NPC). Recent evidence suggests that the transcription factor forkhead box M1 (FoxM1) is involved in chemoresistance. Our group previously confirmed that FoxM1 is overexpressed in NPC. In this study, we investigated the role of FoxM1 in cisplatin resistance of the cell lines 5-8F and HONE-1 and explored its possible mechanism. Our results showed that FoxM1 and NBS1 were both overexpressed in NPC tissues based on data from the GSE cohort (GSE12452). Then, we measured FoxM1 levels in NPC cells and found FoxM1 was overexpressed in NPC cell lines and could be stimulated by cisplatin. MTT and clonogenic assays, flow cytometry, ${\gamma}H2AX$ immunofluorescence, qRT-PCR, and western blotting revealed that downregulation of FoxM1 sensitized NPC cells to cisplatin and reduced the repair of cisplatin-induced DNA double-strand breaks via inhibition of the MRN (MRE11-RAD50-NBS1)-ATM axis, which might be related to the ability of FoxM1 to regulate NBS1. Subsequently, we demonstrated that enhanced sensitivity of FoxM1 knockdown cells could be reduced by overexpression of NBS1. Taken together, our data demonstrate that downregulation of FoxM1 could improve the sensitivity of NPC cells to cisplatin through inhibition of MRN-ATM-mediated DNA repair, which could be related to FoxM1-dependent regulation of NBS1.

• Journal of the Korean Society of Radiology
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• v.81 no.1
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• pp.81-100
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• 2020

Magnetic resonance neurography (MRN) has been increasingly used in recent years for the assessment of peripheral neuropathies. Fat suppression T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI) have typically been used to provide high contrast MRN. Isotropic 3-dimensional (3D) sequences with fast spin echo, post-processing imaging techniques, and fast imaging methods, among others, allow good visualization of peripheral nerves that have a small diameter, complex anatomy, and oblique course within a reasonable scan time. However, there are still several issues when performing high contrast and high resolution MRN including standard sequence; fat saturation techniques; balance between resolution, field of view, and slice thickness; post-processing techniques; 2D vs. 3D image acquisition; different T2 contrasts between proximal and distal nerves; high T2 signal intensity of adjacent veins or joint fluid; geometric distortion; and appropriate p-values on DWI. The proper understanding of these issues will help novice radiologists evaluate peripheral neuropathies using MRN.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2019.11a
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• pp.94-97
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• 2019

자율운항선박, 스마트 항만 등 4차 산업혁명 기술이 해상 환경에 확산되고 있는 상황에서 해상 광역인프라인 항로표지를 정보의 디지털화, 정보교환 체계의 표준화, 정보수집의 다양화, 통합 DB 구축 및 첨단 ICT 기술을 접목하여 스마트함으로써 정보의 생산·수집·가공·공유를 위한 플랫폼 체계를 구축하여 미래 해상환경 수요에 충족하고자 한다.

• Korean Journal of Radiology
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• v.21 no.4
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• pp.483-493
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• 2020

Objective: To evaluate the distribution and characteristics of peripheral nerve abnormalities in chronic inflammatory demyelinating polyneuropathy (CIDP) using magnetic resonance neurography (MRN) and to examine the diagnostic efficiency. Materials and Methods: Thirty-one CIDP patients and 21 controls underwent MR scans. Three-dimensional sampling perfections with application-optimized contrasts using different flip-angle evolutions and T1-/T2- weighted turbo spin-echo sequences were performed for neurography of the brachial and lumbosacral (LS) plexus and cauda equina, respectively. Clinical data and scores of the inflammatory Rasch-built overall disability scale (I-RODS) in CIDP were obtained. Results: The bilateral extracranial vagus (n = 11), trigeminal (n = 12), and intercostal nerves (n = 10) were hypertrophic. Plexus hypertrophies were observed in the brachial plexus of 19 patients (61.3%) and in the LS plexus of 25 patients (80.6%). Patterns of hypertrophy included uniform hypertrophy (17 [54.8%] brachial plexuses and 21 [67.7%] LS plexuses), and multifocal fusiform hypertrophy (2 [6.5%] brachial plexuses and 4 [12.9%] LS plexuses) was present. Enlarged and/or contrast-enhanced cauda equina was found in 3 (9.7%) and 13 (41.9%) patients, respectively. Diameters of the brachial and LS nerve roots were significantly larger in CIDP than in controls (p < 0.001). The largest AUC was obtained for the L5 nerve. There were no significant differences in the course duration, I-RODS score, or diameter between patients with and without hypertrophy. Conclusion: MRN is useful for the assessment of distribution and characteristics of the peripheral nerves in CIDP. Compared to other regions, LS plexus neurography is more sensitive for CIDP.