• Journal of the Korean Society of Radiology
• /
• v.15 no.7
• /
• pp.991-998
• /
• 2021

The purpose of this study is to investigate the image quality of the SE-EPI and SSH-TSE technique for MR DWI. Datum were analyzed for 35 PACS transmission datum(Normal part: 12 males, 13 females, Cerebral Infarction: 10(5males and 5females), and average age 68±7.32), randomly selected patients who underwent MRDWI tests. The equipment used was Ingenia CX 3.0T, SSH_TSE and SE-EPI pulse sequence and 32 Ch. head coil were used for data acquisition. Image evaluation was performed on the paired t-test and Wilcoxon tests, and was considered significant when the p value was 0.05 or less. As a result of quantitative analysis of SNR for DWI images, the mean and standard deviation values of 4 parts (WM, GM, BG, Cerebellum) in ADC (s/mm2), Diffusion b=0, 1000 images were higher in SE-EPI techniques(ADC: 120.50 ± 40, b=0: 54.50 ± 35.91, b=1000: 91.61 ± 36.63) than in SSH-TSE techniques(ADC: 99.69 ± 31.10, b=0: 43.52 ± 25.00 , b=1000: 60.74 ± 24.85)(p<0.05). The CNR values for GM-WM, BG-WM sites were also higher in SE-EPI technique (ADC: 116.08 ± 43.30, b=0:27.23 ± 09.10, b=1000: 78.50 ± 16.56) than in SSH-TSE(ADC: 101.08 ± 36.81, b=0: 23.96 ± 07.79 , b=1000: 74.30 ± 14.22). As a visual evaluation of observers, ghost artifact, magnetic susceptibility artifacts and overall image quality for SE-TSE and SSH-TSE all yielded high results from SSH-TSE techniques(ADC:3.6 ± 0.1, 2.8 ± 0.2, b=0: 4.3 ± 0.3, 3.4 ± 0.1 b=1000: 4.3 ± 0.2, 3.5 ± 0.2, p=0.000). In conclusion, the SE-EPI technique obtained an superiority in SNR and CNR measurements using SSH-TSE, SE-EPI. In the qualitative analysis, the SSH-TSE pulse sequence was obtained a high result according to the pulse sequence characteristics.

• Journal of the Korean Society of Radiology
• /
• v.81 no.3
• /
• pp.676-687
• /
• 2020

Purpose To analyze the altered brain regions and intrinsic brain activity patterns in trauma-exposed firefighters without posttraumatic stress disorder (PTSD). Materials and Methods Resting-state functional MRI (rsfMRI) was performed for all subjects. Thirty-one firefighters over 40 years of age without PTSD (31 men; mean age, 49.8 ± 4.7 years) were included. Twenty-six non-traumatized healthy controls (HCs) (26 men; mean age, 65.3 ± 7.84 years) were also included. Voxel-based morphometry was performed to investigate focal differences in the brain anatomy. Seed-based functional connectivity analysis was performed to investigate differences in spontaneous brain characteristics. Results The mean z-scores of the Seoul Verbal Learning Test for immediate and delayed recall, Controlled Oral Word Association Test (COWAT) score for animals, and COWAT phonemic fluency were significantly lower in the firefighter group than in the HCs, indicating decreased neurocognitive function. Compared to HCs, firefighters showed reduced gray matter volume in the left superior parietal gyrus and left inferior temporal gyrus. Further, in contrast to HCs, firefighters showed alterations in rsfMRI values in multiple regions, including the fusiform gyrus and cerebellum. Conclusion Structural and resting-state functional abnormalities in the brain may be useful imaging biomarkers for identifying alterations in trauma-exposed firefighters without PTSD.

• Journal of the Korean Society of Radiology
• /
• v.82 no.4
• /
• pp.862-875
• /
• 2021

Purpose To investigate the MRI features associated with neural foraminal stenosis (NFS) in patients older than 60 years with lumbar (L) radiculopathy. Materials and Methods This study included 133 retrospectively selected patients older than 60 years with lumbar radiculopathy who had undergone a lumbar spine MRI (from January 2018 to April 2018). For L4/L5 and L5/sacral (S)1 levels, NFS was reviewed blindly by two radiologists. Spondylolisthesis, retrolisthesis, disc height loss, disc bulging/herniation/central canal stenosis, ligamentum flavum thickening, and facet hypertrophy were evaluated separately for the NFS and non-NFS groups, and they were compared using univariate and multivariate analyses. Results The univariate analysis revealed that disc height loss (p = 0.006) was associated with NFS for L4/L5. For L5/S1, both spondylolisthesis (p = 0.005) and facet hypertrophy (p = 0.006) were associated with NFS. The multivariate logistic analysis revealed that disc height loss was associated with NFS for L4/L5 [odds ratio (OR) = 4.272; 95% confidence interval (CI) 1.736-10.514]. For L5/S1, spondylolisthesis (OR = 3.696; 95% CI 1.297-10.530) and facet hypertrophy (OR = 6.468; 95% CI 1.283-32.617) were associated with NFS. Conclusion Disc height loss was associated with NFS for L4/L5 and spondylolisthesis and facet hypertrophy were associated with NFS for L5/S1.

• Journal of the Korean Society of Radiology
• /
• v.82 no.3
• /
• pp.654-669
• /
• 2021

Purpose To evaluate the accuracy of MRI in predicting the pathological complete response (pCR) and the residual tumor size of breast cancer after neoadjucant chemotherapy (NAC), and to determine the factors affecting the accuarcy. Materials and Methods Eighty-eight breast cancer patients who underwent surgery after NAC at our center between 2010 and 2017 were included in this study. pCR was defined as the absence of invasive cancer on pathological evaluation. The maximum diameter of the residual tumor on post-NAC MRI was compared with the tumor size of the surgical specimen measured pathologically. Statistical analysis was performed to elucidate the factors affecting pCR and the residual tumor size-discrepancy between the MRI and the pathological measurements. Results The pCR rate was 10%. The diagnostic accuracy of MRI and the area under the curve for predicting pCR were 90.91% and 0.8017, respectively. The residual tumor sizes obtained using MRI and pathological measurements showed a strong correlation (r = 0.9, p < 0.001), especially in patients with a single mass lesion (p = 0.047). The size discrepancy between MRI and the pathological measurements was significantly greater in patients with the luminal type (p = 0.023) and multifocal tumors/non-mass enhancement on pre-NAC MRI (p = 0.047). Conclusion MRI is an accurate tool for evaluating pCR and residual tumor size in breast cancer patients who receive NAC. Tumor subtype and initial MRI features affect the accuracy of MRI.

• Journal of the Korean Society of Radiology
• /
• v.81 no.2
• /
• pp.365-378
• /
• 2020

Purpose This study was performed to determine whether the T1 relaxation time of gadoxetic acid-enhanced liver MR imaging is useful for detecting and staging liver fibrosis in patients with chronic liver disease. Materials and Methods One hundred and three patients with suspected focal liver lesion underwent MR imaging and Fibroscan. Fibroscan was chosen as the reference standard for classifying liver fibrosis. T1 relaxation times were acquired before (preT1), 20 minutes after (postT1) contrast administration, and reduction rate of T1 relaxation time (rrT1) on transverse 3D VIBE (volumetric interpolated breath-hold examination) sequence using 3T MR imaging. The optimal cut-off values for the fibrosis staging were determined with ROC analysis. Results PreT1 and postT1 increased and rrT1 decreased constantly with increasing severity of liver fibrosis according to the METAVIR score (F0-F4). There were statistically significant differences between F2 and F3 in preT1 (F2, 836.0 ± 74.7 ms; F3, 888.6 ± 77.5 ms, p < 0.05) and between F3 and F4 in postT1 (F3, 309.0 ± 80.2 ms; F4, 406.6 ± 147.7 ms, p < 0.05) and rrT1 (F3, 65.4 ± 7.7%; F4, 57.3 ± 11.4%, p < 0.05). ROC analysis revealed that combination test (preT1 + postT1) was the best test for predicting liver fibrosis. Conclusion PreT1 and postT1 increased constantly with increasing severity of liver fibrosis. T1 mapping in gadoxetic acid-enhanced liver MR imaging could be a helpful complementary sequence to determine the liver fibrosis stage.

• Journal of the Korean Society of Radiology
• /
• v.84 no.5
• /
• pp.1066-1079
• /
• 2023

Purpose Distinguishing intradural extramedullary (IDEM) spinal ependymoma from myxopapillary ependymoma is challenging due to the location of IDEM spinal ependymoma. This study aimed to investigate the utility of clinical and MR imaging features for differentiating between IDEM spinal and myxopapillary ependymomas. Materials and Methods We compared tumor size, longitudinal/axial location, enhancement degree/pattern, tumor margin, signal intensity (SI) of the tumor on T2-weighted images and T1-weighted image (T1WI), increased cerebrospinal fluid (CSF) SI caudal to the tumor on T1WI, and CSF dissemination of pathologically confirmed 12 IDEM spinal and 10 myxopapillary ependymomas. Furthermore, classification and regression tree (CART) was performed to identify the clinical and MR features for differentiating between IDEM spinal and myxopapillary ependymomas. Results Patients with IDEM spinal ependymomas were older than those with myxopapillary ependymomas (48 years vs. 29.5 years, p < 0.05). A high SI of the tumor on T1W1 was more frequently observed in IDEM spinal ependymomas than in myxopapillary ependymomas (p = 0.02). Conversely, myxopapillary ependymomas show CSF dissemination. Increased CSF SI caudal to the tumor on T1WI was observed more frequently in myxopapillary ependymomas than in IDEM spinal ependymomas (p < 0.05). Dissemination to the CSF space and increased CSF SI caudal to the tumor on T1WI were the most important variables in CART analysis. Conclusion Clinical and radiological variables may help differentiate between IDEM spinal and myxopapillary ependymomas.

• Journal of the Korean Society of Radiology
• /
• v.8 no.6
• /
• pp.317-323
• /
• 2014

This study aims to suggest and test methods using an orally inserted guiding device in order to improve a motion artifact by involuntary oral motor such as removing one's dentures and swallowing saliva clinically structured cervical spine scan and to make the optimal image by minimizing motion artifact. A cervical spine test was conducted with 30 patients who wore dentures among those who had a cervical spinal disease from January 1, 2014 through June 30, 2014. As for testing methods, after removing denture, T1-TSE-Sagittal, T2-TSE-Sagittal, T1-TSE-Axial and T2-TSE-Axial were obtained in a normal position and a supine position; the orally inserted guiding device was inserted in patients' mouth; and then T1-TSE-Axial and T2-TSE-Axial were retested. As a result, in SNR, T1-TSE-Axial before inserting an orally inserted guiding device was $22.33{\pm}8.59$; T1-TSE-Axial after inserting the orally inserted guiding device was $25.21{\pm}7.93$; T2-TSE-Axial before inserting the orally inserted guiding device was $14.49{\pm}5.74$; and T2-TSE-Axial after inserting the orally inserted guiding device was $16.61{\pm}6.72$. In CNR, T1-TSE-Axial was measured at $0.23{\pm}0.01$ while T2-TSE-Axial at $0.21{\pm}0.01$. As a result of the qualitative analysis, T1-TSE-Axial before inserting the orally inserted guiding device was $3.49{\pm}0.11$; T1-TSE-Axial after inserting the orally inserted guiding device was $3.95{\pm}0.14$; T2-TSE-Axial before inserting the orally inserted guiding device was $3.25{\pm}0.18$; and T2-TSE-Axial after inserting the orally inserted guiding device was $3.68{\pm}0.09$. As a result of using an orally inserted guiding device, the resolution and contrast of the images improved as the patients' involuntary artifact decreased because of removing dentures and swallowing saliva, and it was found that the interpretation of the images and identification of the diseases improved.

• IMMUNE NETWORK
• /
• v.1 no.1
• /
• pp.87-94
• /
• 2001

Background: Cytokine-mediated ex vivo expansion has been proposed as a means of increasing the number of cord blood (CB) hematopoietic stem cells for transplantation. As well as stem cell number, stromal cells are necessary for functional maturation of hematopoiesis. The purpose of this study was to analyze the development of stromal cells during ex vivo expansion of CB $CD34^+$ cells. Methods : $CD34^+$ cells were purified from CB by magnetic bead selection. The levels of of interleukin-3, interleukin-$1{\beta}$, interleukin-6, granulocyte macrophagecolony stimulating factor and tumor necrosis factor-${\alpha}$ were measured in culture supernatants on 0, 1, 2, and 3 weeks, using ELISA techniques. CB $CD34^+$ cells were expanded in Iscoves modified Dulbeccos medium in the presence of several cytokines. The expression of E-selectin, vascular cell adhesion molecule-1, intercellular adhesion molecule-1, platelet/endothelial cell adhesion molecule-1, von Willebrand factor, vimentin, and CD14 in newly developed stromal cells was examined by immunocytochemical method. Relevant extracellular matrix (ECM) proteins and proper cytokines were also assayed for the most suitable condition for expansion of stromal cells. Results: Several cytokines were found to have been produced by CB $CD34^+$ cells as well as bone marrow-derived $CD34^+$ cells. During ex vivo expansion of CB $CD34^+$ cells, stromal cells appeared in the culture by day 4 and expanded over the following 7-10 days before being confluent by day 2 1. These cells expressed surface markers characteristic of cells of endothelial lineage. Furthermore, these stroaml cells also expanded effectively when treated with thrombopoietin+flt-3 ligand+stem cell factor+leukemia inhibitory factor or 0.1% poly-L-lysine-coated wells. Conclusion: Stromal cells were developed during ex vivo expansion of CB $CD34^+$ cells and that this development could be enhanced further by treating the stromal cells with cytokines or ECM.

• Economic and Environmental Geology
• /
• v.49 no.6
• /
• pp.417-432
• /
• 2016

It was firstly revealed in this research that the marine terrace of the Ijin-ri (Bukpyung-myeon, Haenam-gun) was formed during the last interglacial (Marine Isotope Stage 5e; MIS 5e). The marine terrace totally ranging from 4.8 m (asl) to 8.8 m (asl) is subdivided into 4 units; Unit I ranges 4.8-5.3 m, unit II ranges 5.3-6.9 m, unit III ranges 6.9-8.3 m, and unit IV ranges 8.3-8.8 m. Strong evidences that units II and III were formed during MIS5e were obtained based on OSL dating, the physical characterizations such as particle size distribution, magnetic susceptibility and water content, principal element and trace element analyses, and quantitative clay mineral analysis for samples at the 30 cm intervals. The rounded gravels on the marine terrace are regarded to be originated from the clastic materials transported directly from the surrounding mountains toward the marine and abraded in the coastal area, without any fluvial processes. During the warmest period (125k, unit II), the increase in rainfall, along with the rapid rise in sea level, was likely caused the high amount of clastic materials transported to the upper part of the beach. As a result of comparing clay mineral ratios of study site with those derived from sediments of either tidal flats, or the Yellow Sea, it is interpreted that the sediments of study site were influenced from the marine. The results will be used to investigate the hydrological activity and sedimentary environment during the high sea level in the past.

• The Journal of the Korea Contents Association
• /
• v.9 no.12
• /
• pp.683-690
• /
• 2009

The purpose of this study is to evaluate the usefulness of high-b-values diffusion weighted magnetic resonance imaging for the preoperative detection of focal rectum cancers. 60patients with diffusion weighted imaging were evaluated for the presence of rectal cancers. Forty were male and twenty were female, and their ages ranged from 38 to 71 (mean, 56) years. Used equipment was 1.5Tesla MRI((GE, General Electric Medical System, Excite HD). Examination protocols were used the fast spin echo T2, T1 weighted imaging. All examination protocols were performed by the same location with diffusion weighted imaging for accuracy detection. The b-values used in DWI were 250, 500, 750, 1000. 1500, 2000$(s/mm^2)$. The rectum, bladder to tumor contrast-to-noise ratio (CNR) of MR images were quantitativlely analyzed using GE software Functool tool, four experienced radiologists and three radiotechnologists qualitatively evaluated image quality in terms of image artifacts, lesion conspicuity and rectal wall. These data were analysed by using ANOVA and Freedman test with each b-value(p<0.05). Contrast to noise ratio of rectum, bladder and tumor in b-value 1000 were 27.21, 24.44, respectively(p<0.05) and aADC value was $0.73\times10^{-3}$. As a qualitative analysis, the conspicuity and discrimination from the rectal wall of lesions were high results as $4.0\pm0.14$, $4.4\pm0.16$ on b-value 1000(p<0.05), image artifacts were high results as $4.8\pm0.25$ on b-value 2000(p<0.05). In conclusion, DWI was provided useful information with depicting the pre-operative detection of rectal cancers, High-b-value 1000 image was the most excellent DWI value.