1.Transarterial Embolization of a Carotid Cavernous Fistula with Guglielmi Detachable Coils: A Case Report.
Seung Kug BAIK ; Hak Jin KIM ; Han Young CHOI ; Bong Gi KIM
Journal of the Korean Radiological Society 1998;38(4):585-587
In the management of carotid cavernous fistula, detachable balloon has become the treatment of choice.However, technical difficulties are not uncommon, and transarterial balloon embolization fail in 5% to 10% ofcases. Failure occurs because in some patients, the fistula orifice may be too small to allow entry. Using atracker catheter system with Guglielmi detachable coils, we achieved successful transarterial occlusion of acarotid cavernous fistula with a small fistula.
Balloon Occlusion
;
Catheters
;
Fistula*
;
Humans
2.The Usefulness of Scoring System Distinguishing between Benign and Malignant Breast Masses on Ultrasonogram.
Won Kyu PARK ; Kyoung Kug BAE ; Jong O CHOI ; Mi Soo HWANG ; Woo Mok BYUN ; Bok Hwan PARK ; Hwa Jin LEE
Journal of the Korean Radiological Society 1997;36(5):909-914
PURPOSE: To evaluate a scoring system based on ultrasonographic findings as a means of distinguishing between benign and malignant solid breast masses. MATERIALS AND METHODS: Histopathologically confirmed benign (n=102) and malignant (n=73) breast masses which ultrasonographic findings of histopathologic masses were reviewed for shape, border, internal echo, boundary echo, posterior echo, lateral echo, and ratio of transverse to anteroposterior diameter. There were statistically significant (p < 0.001 ; chi-square test) differences in each feature for benign and malignant lesions. The findings suggesting benignancy, equivocality, and malignancy of the masses were scored as 0, 1, and 2 respectively. The scores for all features were summed for each lesion. An ROC curve was obtained. RESULTS: When the score was 6, five benign and seven malignant cases were found. Scores of 0 and 1 indicated benign masses and a score above 11, malignancy. The turning point was a score of 6, so a score above 7 suggests malignancy. CONCLUSION: A ultrasonographic scoring system can be used to characterise breast masses. A score of a mass above 7 suggests probable malignancy and a score below 5 suggests benignancy.
Breast*
;
ROC Curve
;
Ultrasonography*
3.Detection of Foreign Antigen-specific CD4+Foxp3+ Regulatory T Cells by MHC Class II Tetramer and Intracellular CD154 Staining.
Immune Network 2013;13(6):264-274
The unrestricted population of CD4+Foxp3+ regulatory T (Treg) cells, which have been known to control the expression of autoimmune diseases and protective immunity to inflammatory reactions, has led to greater appreciation of functional plasticity. Detecting and/or isolating Ag-specific CD4+Foxp3+ Tregs at the single cell level are required to study their function and plasticity. In this study, we established and compared both MHC class II tetramer and intracellular CD154 staining, in order to detect CD4+Foxp3+ Treg specific for foreign Ag in acute and chronic infections with lymphocytic choriomeningitis virus (LCMV). Our results revealed that MHC class II tetramer staining showed a lower detection rate of LCMV GP66-77-specific CD4+ T cells because most of MHC class II tetramers were unbound and unstable when combined staining was performed with intracellular cytokines. In contrast, intracellular CD154 staining was revealed to be easier and simple for detecting LCMV GP66-77-specific CD4+ T cells, compared to MHC class II tetramer staining. Subsequently, we employed intracellular CD154 staining to detect LCMV GP66-77-specific CD4+Foxp3+ Tregs using Foxp3GFP knock-in mouse, and found that LCMV GP66-77-specific CD4+Foxp3+ Tregs and polyclonal CD4+Foxp3+ Tregs showed differential expansion in mice infected with LCMV Arms or Cl13 at acute (8 and 13 days pi) and chronic phases (35 days pi). Therefore, our results provide insight into the valuable use of intracellular CD154 staining to detect and characterize foreign Ag-specific CD4+Foxp3+ Treg in various models.
Animals
;
Arm
;
Autoimmune Diseases
;
Cytokines
;
Lymphocytic choriomeningitis virus
;
Mice
;
Plastics
;
T-Lymphocytes
;
T-Lymphocytes, Regulatory*
4.Tuberculous Pneumonia: CT Findings in 20 Patients.
Mi Jeong SHIN ; Seung Kug BALK ; Bong Gi KIM ; Han Young CHOI ; Eun Joo JEON ; Tong Jin CHUN ; Woo Hyeon AHN
Journal of the Korean Radiological Society 1995;32(3):405-410
PURPOSE: To evaluate CT findings of tuberculous pneumonia mainly presenting as parenchymal consolidation. MATERIALS & METHODS: CT scans of twenty patients with tuberculous pneumonia were retrospectively reviewed. Analyses included the location, extent, and homogeneity of consolidation, presence of volume loss of involved lung and air-bronchogram, associated lesions suggesting previous tuberculous infection and evidence of bronchogenic spread. RESULTS: The location of consolidation revealed relatively even distribution without any specific predilection site. The areas of consolidation were irregular in margin (95%), inhomogeneous in attenuation (75%) including focal areas of low attenuation and multiple cavities within it. Volume loss (70%) of the involved lobe was associated. There were lesions suggesting previous tuberculous infection (95%) in the surrounding area and evidences of bronchogenic spread (100%) such as poorly-defined nodules and Iobular consolidations in the remote site from main consolidation. CONCLUSION: In tuberculous pneumonia, the areas of consolidation are irregular in margin and inhomogeneous in attenuation on CT scan. The evidences of bronchogenic spread and lesions suggesting previous tuberculous infection are almost always associated in the surrounding or remote site from main consolidation.
Humans
;
Lung
;
Pneumonia*
;
Retrospective Studies
;
Tomography, X-Ray Computed
5.Synthesis of T2-weighted images from proton density images using a generative adversarial network in a temporomandibular joint magnetic resonance imaging protocol
Chena LEE ; Eun-Gyu HA ; Yoon Joo CHOI ; Kug Jin JEON ; Sang-Sun HAN
Imaging Science in Dentistry 2022;52(4):393-398
Purpose:
This study proposed a generative adversarial network (GAN) model for T2-weighted image (WI) synthesis from proton density (PD)-WI in a temporomandibular joint (TMJ) magnetic resonance imaging (MRI) protocol.
Materials and Methods:
From January to November 2019, MRI scans for TMJ were reviewed and 308 imaging sets were collected. For training, 277 pairs of PD- and T2-WI sagittal TMJ images were used. Transfer learning of the pix2pix GAN model was utilized to generate T2-WI from PD-WI. Model performance was evaluated with the structural similarity index map (SSIM) and peak signal-to-noise ratio (PSNR) indices for 31 predicted T2-WI (pT2). The disc position was clinically diagnosed as anterior disc displacement with or without reduction, and joint effusion as present or absent. The true T2-WI-based diagnosis was regarded as the gold standard, to which pT2-based diagnoses were compared using Cohen’s ĸ coefficient.
Results:
The mean SSIM and PSNR values were 0.4781(±0.0522) and 21.30(±1.51) dB, respectively. The pT2 protocol showed almost perfect agreement (ĸ=0.81) with the gold standard for disc position. The number of discordant cases was higher for normal disc position (17%) than for anterior displacement with reduction (2%) or without reduction (10%). The effusion diagnosis also showed almost perfect agreement (ĸ=0.88), with higher concordance for the presence (85%) than for the absence (77%) of effusion.
Conclusion
The application of pT2 images for a TMJ MRI protocol useful for diagnosis, although the image quality of pT2 was not fully satisfactory. Further research is expected to enhance pT2 quality.
6.Computed tomography and magnetic resonance imaging characteristics of giant cell tumors in the temporomandibular joint complex
Yoon Joo CHOI ; Chena LEE ; Kug Jin JEON ; Sang-Sun HAN
Imaging Science in Dentistry 2021;51(2):149-154
Purpose:
This study aimed to investigate the computed tomography and magnetic resonance imaging features of giant cell tumors in the temporomandibular joint region to facilitate accurate diagnoses.
Materials and Methods:
From October 2007 to June 2020, 6 patients (2 men and 4 women) at Yonsei University Dental Hospital had histopathologically proven giant cell tumors in the temporomandibular joint. Their computed tomography and magnetic resonance imaging findings were reviewed retrospectively, and the cases were classified into 3 types based on the tumor center and growth pattern observed on the radiologic findings.
Results:
The age of the 6 patients ranged from 25 to 53 years. Trismus was found in 5 of the 6 cases. One case recurred. The mean size of the tumors, defined based on their greatest diameter, was 32 mm (range, 15–41 mm). The characteristic features of all cases were a heterogeneously-enhancing tumorous mass with a lobulated margin on computed tomographic images and internal multiplicity of signal intensity on T2-weighted magnetic resonance images. According to the site of origin, 3 tumors were bone-centered, 2 were soft tissue-centered, and 1 was peri-articular.
Conclusion
Computed tomography and magnetic resonance imaging yielded a tripartite classification of giant cell tumors of the temporomandibular joint according to their location on imaging. This study could help clinicians in the differential diagnosis of giant cell tumors and assist in proper treatment planning for tumorous diseases of the temporomandibular joint.
7.Efficacy of corticosteroid ductal irrigation in acute salivary gland inflammation induced in a rat model
Chena LEE ; Ari LEE ; Hak-Sun KIM ; Yoon Joo CHOI ; Kug Jin JEON ; Sang-Sun HAN
Imaging Science in Dentistry 2022;52(1):61-66
Purpose:
This study aimed to compare the therapeutic effects of corticosteroid irrigations and normal saline irrigations in the early inflammatory state of the salivary gland.
Materials and Methods:
Adult male Wistar rats were divided into experimental (n=6) and control (n=3) groups. Inflammation was induced in the experimental subjects on both sides of the submandibular gland with ligation. After 14 days, both sides of the glands were de-ligated and retroductal irrigation using saline (n=3) and a corticosteroid (n=3) was performed on the left sides only. The controls (n=3) were used to normalize the gland state for the effects of diet and aging. Magnetic resonance imaging was performed to confirm inflammation and post-irrigation gland recovery by measuring relative signal intensity (SI). The glands were excised for histological examination.
Results:
All experimental animals showed inflamed glands with increased SI and subsequent recovery of the gland with decreased SI to varying degrees. The SI of the controls showed no significant changes during the overall period. The mean SI change of the irrigated gland was higher than that of the non-irrigated side, without a significant difference. The corticosteroid-irrigated glands showed a greater change in SI than that of the saline-irrigated glands. Histology revealed that inflammation was not observed in most of the irrigated glands, while mild to moderate quantities inflammatory cells were found in non-irrigated glands.
Conclusion
Corticosteroid irrigation mitigated the early stages of salivary gland inflammation more effectively than normal saline.
8.Image quality-based dose optimization in pediatric cone-beam computed tomography:A pilot methodological study
Hak-Sun KIM ; Yoon Joo CHOI ; Kug Jin JEON ; Sang-Sun HAN ; Chena LEE
Imaging Science in Dentistry 2024;54(3):264-270
Purpose:
This study aimed to propose a methodological approach for reducing the radiation dose in pediatric conebeam computed tomography (CBCT), focusing exclusively on balancing image quality with dose optimization.
Materials and Methods:
The dose-area product (DAP) for exposure was reduced using copper-plate attenuation of an X-ray source. The thickness of copper (Cu) was increased from 0 to 2.2 mm, and 10 different DAP levels were used. The QUART DVT_AP phantom and pediatric radiologic dentiform were scanned under the respective DAP levels. The contrast-to-noise ratio (CNR), image homogeneity, and modulation transfer function (MTF) were analyzed using the QUART DVT_AP phantom. An expert evaluation (overall image grade, appropriateness of field of view, artifacts, noise, and resolution) was conducted using pediatric dentiform images. The critical DAP level was determined based on phantom and dentiform analysis results.
Results:
CNR and image homogeneity decreased as the DAP was reduced; however, there was an inflection point of image homogeneity at Cu 1.6 mm (DAP = 138.00 mGy·cm2 ), where the value started increasing. The MTF showed constant values as the DAP decreased. The expert evaluation of overall image grades showed “no diagnostic value” for dentiform images with Cu 1.9-2.2 mm (DAP = 78.00-103.33 mGy·cm2 ). The images with Cu 0-1.6 mm (DAP = 138.00-1697.67 mGy·cm2 ) had a “good,” “moderate,” or “poor but interpretable” grade.
Conclusion
Reducing DAP beyond a 1.6-mm Cu thickness degraded CBCT image quality. Image homogeneity and clinical image grades indicated crucial decision points for DAP reduction in pediatric CBCT scans.
9.Image quality-based dose optimization in pediatric cone-beam computed tomography:A pilot methodological study
Hak-Sun KIM ; Yoon Joo CHOI ; Kug Jin JEON ; Sang-Sun HAN ; Chena LEE
Imaging Science in Dentistry 2024;54(3):264-270
Purpose:
This study aimed to propose a methodological approach for reducing the radiation dose in pediatric conebeam computed tomography (CBCT), focusing exclusively on balancing image quality with dose optimization.
Materials and Methods:
The dose-area product (DAP) for exposure was reduced using copper-plate attenuation of an X-ray source. The thickness of copper (Cu) was increased from 0 to 2.2 mm, and 10 different DAP levels were used. The QUART DVT_AP phantom and pediatric radiologic dentiform were scanned under the respective DAP levels. The contrast-to-noise ratio (CNR), image homogeneity, and modulation transfer function (MTF) were analyzed using the QUART DVT_AP phantom. An expert evaluation (overall image grade, appropriateness of field of view, artifacts, noise, and resolution) was conducted using pediatric dentiform images. The critical DAP level was determined based on phantom and dentiform analysis results.
Results:
CNR and image homogeneity decreased as the DAP was reduced; however, there was an inflection point of image homogeneity at Cu 1.6 mm (DAP = 138.00 mGy·cm2 ), where the value started increasing. The MTF showed constant values as the DAP decreased. The expert evaluation of overall image grades showed “no diagnostic value” for dentiform images with Cu 1.9-2.2 mm (DAP = 78.00-103.33 mGy·cm2 ). The images with Cu 0-1.6 mm (DAP = 138.00-1697.67 mGy·cm2 ) had a “good,” “moderate,” or “poor but interpretable” grade.
Conclusion
Reducing DAP beyond a 1.6-mm Cu thickness degraded CBCT image quality. Image homogeneity and clinical image grades indicated crucial decision points for DAP reduction in pediatric CBCT scans.
10.The Analysis of Incidental Findings on Temporomandibular Joint Magnetic Resonance Imaging
Yoon Joo CHOI ; Chena LEE ; Kug Jin JEON ; Sang-Sun HAN
Journal of Korean Dental Science 2020;13(1):21-27
Purpose:
The aim of this study was to investigate the types and frequency of the various incidental findings (IFs) on magnetic resonance images (MRI) taken from the patients with temporomandibular disorder (TMD) symptoms.
Materials and Methods:
Temporomandibular joint (TMJ) MRI taken from 1,013 patients with TMD symptoms were evaluated retrospectively. IF was defined as imaging features that were accidentally or unexpectedly found, rather than degenerative bony changes of TMJ complex or disc derangement. They were classified into two groups as TMJ site-specific findings and unexpected findings at other regions. The frequency of the sub groups was analyzed.Result: A total of 26 (2.57%) cases with IFs were classified into 13 cases with TMJ site-specific findings and 13 cases with unexpected findings at other region. TMJ site-specific findings included synovial chondromatosis in 6 cases, synovial cyst in 6 cases and osteochondroma in one case. Unexpected findings included salivary gland tumor in 3 cases, developmental cyst in 3 cases, vascular malformation in 2 cases, mastoiditis in 4 cases and sialadenitis on parotid gland in one case.
Conclusion
When diagnosing TMD through TMJ MRI, clinicians should carefully read the image, considering the possibility of IFs because TMJ MRI can provide pathologic information in TMJ region and other oral and maxillofacial region.