• Korean Journal of Radiology
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• v.22 no.6
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• pp.867-879
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• 2021

Objective: To compare the screening performance of diffusion-weighted (DW) MRI and combined mammography and ultrasound (US) in detecting clinically occult contralateral breast cancer in women with newly diagnosed breast cancer. Materials and Methods: Between January 2017 and July 2018, 1148 women (mean age ± standard deviation, 53.2 ± 10.8 years) with unilateral breast cancer and no clinical abnormalities in the contralateral breast underwent 3T MRI, digital mammography, and radiologist-performed whole-breast US. In this retrospective study, three radiologists independently and blindly reviewed all DW MR images (b = 1000 s/mm² and apparent diffusion coefficient map) of the contralateral breast and assigned a Breast Imaging Reporting and Data System category. For combined mammography and US evaluation, prospectively assessed results were used. Using histopathology or 1-year follow-up as the reference standard, cancer detection rate and the patient percentage with cancers detected among all women recommended for tissue diagnosis (positive predictive value; PPV2) were compared. Results: Of the 30 cases of clinically occult contralateral cancers (13 invasive and 17 ductal carcinoma in situ [DCIS]), DW MRI detected 23 (76.7%) cases (11 invasive and 12 DCIS), whereas combined mammography and US detected 12 (40.0%, five invasive and seven DCIS) cases. All cancers detected by combined mammography and US, except two DCIS cases, were detected by DW MRI. The cancer detection rate of DW MRI (2.0%; 95% confidence interval [CI]: 1.3%, 3.0%) was higher than that of combined mammography and US (1.0%; 95% CI: 0.5%, 1.8%; p = 0.009). DW MRI showed higher PPV2 (42.1%; 95% CI: 26.3%, 59.2%) than combined mammography and US (18.5%; 95% CI: 9.9%, 30.0%; p = 0.001). Conclusion: In women with newly diagnosed breast cancer, DW MRI detected significantly more contralateral breast cancers with fewer biopsy recommendations than combined mammography and US.

• The Journal of the Korea Contents Association
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• v.9 no.4
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• pp.247-253
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• 2009

PACS(Picture archiving communication system) is a system that enables medical images such as X -ray, CT, MRI, PET to be stored electronically viewed on computer screens so that doctors and other authorized people can access search the information as needed. But if they are not in hospital area for example on holiday or at night, that are not able to access the PACS system instantly. We have to solve this problem for more efficient patient care. So we try to suggest a method that use the PDA system that wireless LAN and CDMA cellular phone are equipped. This system may help to access easier to PACS system regardless of the location and can also attribute the development of telemedicne.

• Investigative Magnetic Resonance Imaging
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• v.10 no.2
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• pp.121-125
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• 2006

A 48-year-old man presented with a dermatofibrosarcoma protuberans (DFSP) of the scalp associated with local recurrence. Axial T1- and T2-weighted images demonstrated a well-circumscribed hypointense and intermediate hyperintense mass in the skin and subcutaneous layer of the scalp, respectively. Contrast-enhanced T1-weighted images showed the strongly enhanced mass invasion to the skin, subcutaneous layer and adjacent galeal layer. Scalp DFSP is very uncommon but is an aggressive tumor, so MR imaging diagnosis of the extent of the lesion to underlying structures, and initial wide local resection is important to prevent recurrence.

• The Transactions of the Korea Information Processing Society
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• v.3 no.5
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• pp.1046-1058
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• 1996

In this paper, we describe an abvanced medical diagnostic system using multimedia technologies in netwok environments. In the system, docotors in remote sites perorm medicl diagnosis by exchanging information about patients and 3-D medicl images of malfunctioning body parts, which are reconstructed from 2-D images such as MRI, CT, CR, Angio. The diagnosic conferencing system controls the conferencing process by exchanging audio, information about patients, 3-D medical images and control data. 3-D medicl images are reconstructed by a ray casting method that uses an nalytical integration. Medical databae conists of absic information about patients, Information about medicl images, users, results of dianosis.

• Journal of Biomedical Engineering Research
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• v.23 no.2
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• pp.101-107
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• 2002

This paper presents a segmentation algorithm to extract endocardial contour and epicardial contour of left ventricle in MR Cardiac images. The algorithm is based on a generalized gradient vector flow(GGVF) snake and a prediction of initial contour(PIC). Especially. the proposed algorithm uses physical characteristics of endocardial and epicardial contours, cross profile correlation matching(CPCM), and a mixed interpolation model. In the experiment, the proposed method is applied to short axis MR cardiac image set, which are obtained by Siemens, Medinus, and GE MRI Systems. The experimental results show that the proposed algorithm can extract acceptable epicardial and endocardial walls. We calculate quantitative parameters from the segmented results, which are displayed graphically. The segmented left vents role is visualized volumetrically by surface rendering. The proposed algorithm is implemented on Windows environment using Visual C ++.

• Journal of the Korean Society of Radiology
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• v.79 no.6
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• pp.337-339
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• 2018

Parovarian cyst is usually simple cyst, and accounts for 10%-20% of adnexal masses. Borderline or malignant parovarian tumor is rare, and it contains papillary projection at the smooth inner wall. We report the ultrasonography, CT and MRI findings of a parovarian serous borderline tumor in 19-year-old female presenting left lower quadrant abdominal discomfort for 2 days.

• Journal of the Korean Society of Radiology
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• v.82 no.5
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• pp.1321-1327
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• 2021

Neurofibromatosis type 1 (NF1) is a relatively common inherited disorder characterized by the formation of neurofibromas, pigmentary abnormalities of the skin, Lisch nodules of the iris, and skeletal abnormalities. Multiple cutaneous neurofibromas are benign nerve sheath tumors and the main manifestation of NF1. Cardiac neurofibroma associated with NF1 is very rare, and few cases have been reported in the literature. Herein, we present the CT and MRI findings of a surgically confirmed left ventricular neurofibroma in a 32-year-old female with NF1.

• Journal of the Korean Society of Radiology
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• v.82 no.5
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• pp.1287-1291
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• 2021

Testicular lymphoma is an uncommon testicular tumor that usually presents as a painless mass. It usually shows hypervascularity on color Doppler ultrasound (US) and a mild enhancement on enhanced CT or MRI. We present an unusual case of a testicular lymphoma mimicking a missed testicular torsion in a 67-year-old male patient with right scrotal swelling and intermittent pain for 2 months. Color Doppler US demonstrated the absence of vascularity in the enlarged right testis, and the initial diagnosis was a missed testicular torsion. CT demonstrated a poorly enhancing mass rather than a missed testicular torsion with enhanced small nodular foci at the periphery. The final pathological diagnosis was testicular lymphoma.

• Journal of the Korean Society of Radiology
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• v.83 no.5
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• pp.1147-1152
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• 2022

Presumed idiopathic intracranial hypertension (IIH) is a disorder of elevated intracranial pressure with unknown etiology, and 10% of cases occur secondarily to cerebral venous sinus thrombosis (CVST). CVST may be underestimated when findings of IIH are missed in a normal-weight patient without risk factors of coagulopathy. Here, we present a case of CVST that mimics a neurogenic tumor in the hypoglossal canal in a normal-weight patient without risk factors of coagulopathy.

• Investigative Magnetic Resonance Imaging
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• v.5 no.1
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• pp.57-65
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• 2001

Purpose : $T_2$-weighted half courier Echo Planar Imaging (T2HEPI) method is proposed to reduce measurement time of existing EPI by a factor of 2. In addition, high $T_2$ contrast is obtained for clinical applications. High resolution single-shot EPI images with $T_2$ contrast are obtained with $128{\times}128$ matrix size by the proposed method. Materials and methods : In order to reduce measurement time in EPI, half courier space is measured, and rest of half courier data is obtained by conjugate symmetric filling. Thus high resolution single shot EPI image with $128{\times}128$ matrix size is obtained with 64 echoes. By the arrangement of phase encoding gradients, high $T_2$ weighted images are obtained. The acquired data in k-space are shifted if there exists residual gradient field due to eddy current along phase encoding gradient, which results in a serious problem in the reconstructed image. The residual field is estimated by the correlation coefficient between the echo signal for dc and the corresponding reference data acquired during the pre-scan. Once the residual gradient field is properly estimated, it can be removed by the adjustment of initial phase encoding gradient field between $70^{\circ}$ and $180^{\circ}$ rf pulses. Results : The suggested T2EPl is implemented in a 1.0 Tela whole body MRI system. Experiments are done with the effective echo times of 72ms and 96ms with single shot acquisitions. High resolution($128{\times}128$) volunteer head images with high $T_2$ contrast are obtained in a single scan by the proposed method. Conclusion : Using the half courier technique, higher resolution EPI images are obtained with matrix size of $128{\times}128$ in a single scan. Furthermore $T_2$ contrast is controlled by the effective echo time. Since the suggested method can be implemented by software alone (pulse sequence and corresponding tuning and reconstruction algorithms) without addition of special hardware, it can be widely used in existing MRI systems.