• Korean Journal of Radiology
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• v.20 no.6
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• pp.985-996
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• 2019

Objective: To determine the correlation between cerebral blood flow (CBF) on arterial spin labeling (ASL) MRI and the degree of postoperative revascularization assessed on digital subtraction angiography in children with moyamoya disease (MMD). Materials and Methods: Twenty-one children (9 boys and 12 girls; mean age, 8.4 ± 3.6 years; age range, 3-16 years) with MMD who underwent both pseudocontinuous ASL MRI at 1.5T and catheter angiography before and after superficial temporal artery encephaloduroarteriosynangiosis were included in this retrospective study. The degree of revascularization in the middle cerebral artery (MCA) territory was evaluated on external carotid angiography and was graded on a 3-point scale. On ASL CBF maps, regions of interest were manually drawn over the MCA territory of the operated side at the level of the centrum semi-ovale and over the cerebellum. The normalized CBF (nCBF) was calculated by dividing the CBF of the MCA territory by the CBF of the cerebellum. Changes in nCBFs were calculated by subtracting the preoperative nCBF values from the postoperative nCBF values. The correlation between nCBF changes measured with ASL and the revascularization grade from direct angiography was evaluated. Results: The nCBF value on the operated side increased after the operation (p = 0.001). The higher the degree of revascularization, the greater the nCBF change was: poor revascularization (grade 1), -0.043 ± 0.212; fair revascularization (grade 2), 0.345 ± 0.176; good revascularization (grade 3), 0.453 ± 0.182 (p = 0.005, Jockheere-Terpstra test). The interobserver agreement was excellent for the measured CBF values of the three readers (0.91-0.97). Conclusion: The nCBF values of the MCA territory obtained from ASL MRI increased after the revascularization procedure in children with MMD, and the degree of nCBF change showed a significant correlation with the degree of collateral formation evaluated via catheter angiography.

• Journal of the Korean Society of Radiology
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• v.83 no.4
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• pp.808-829
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• 2022

Hepatocellular carcinoma (HCC) can be diagnosed noninvasively on multiphasic CT and MRI based on its distinctive imaging findings. These features include arterial phase hyperenhancement and washout on portal or delayed phase images. However, radiologists face significant diagnostic challenges because some HCCs exhibit atypical imaging characteristics. In addition to many HCC-mimicking lesions, such as arterioportal shunts, combined HCC-cholangiocarcinoma, intrahepatic cholangiocarcinoma, and hemangioma present a challenge for radiologists in actual clinical practice. The ability to distinguish HCCs from mimickers on initial imaging examinations is crucial for appropriate management and treatment decisions. Therefore, this pictorial review presents the imaging findings of atypical HCCs and HCCs mimicking malignant and benign lesions and discusses important clues that may help narrow down the differential diagnosis.

• The Journal of the Korea Contents Association
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• v.9 no.6
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• pp.178-186
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• 2009

The quality control is needed to ensure the accuracy of medical information and achieved by evaluating the performance of and maintaining the system and practicing various measurements and evaluations. The Korean Institute for Accreditation of Medical Image, therefore, have held educational program for quality control of special medical equipments. The major of programs participants, however, are radiology specialists with only small number of radiological technologists from some hospitals, furthermore, the follow-up education and the share of information between participants and non-participants are insufficient in general, thus, the knowledge level of radiological technologists, regardless of their participation, is relatively low. This study carried out the questionnaire research for the 500 radiological technologists registered in Korean Society of MRI Technology, on the basis of 2008, and performed analysis for five months from May to Oct., 2008. The questionnaires were delivered by post to each radiological technologists and the response rate was 36%(n=180). The results of this revealed that the 86.7% of respondents felt the necessity of inspection on quality management, while only the 27.8% completed the educational program for manager of special medical equipment. and only the half(53.9%) had the knowledge about inspection on quality management. The completion of educational program had no correlations with sex, age, size of occupying hospital, the number of radiological technologists in occupying site and MRI laboratory, career year of general radiologist and in MRI laboratory, and the presence of biomedical engineering department in occupying hospital. The 78.0% of participants at the educational program for quality management held by the Korean Institute for Accreditation of Medical Image had the knowledge about inspection on quality management(p<.05) whereas the 43.9% of the hospitals held such program and the 54.4% of radiological technologists from those hospitals had related knowledge, which indicated that such programs held by hospitals had not effects on the knowledge level of radiological technologists. This indicates also that the contents, methods, and other conditional factors of educational programs are important for the outcome of them.

• Journal of Veterinary Clinics
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• v.31 no.3
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• pp.237-240
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• 2014

A 12-year-old, intact, female Alaskan malamute presented with severe spinal pain and hind limb lameness. On radiographs, a round, demarcated lytic lesion was identified in the central fifth lumbar vertebra. On magnetic resonance imaging (MRI), the lesion involving the spinal cord appeared hypointense on T1 weighted, hyperintense on T2 weighted, heterogeneously enhanced on post-contrast T1 weighted, and hypointense on GE images. A focal, small, ill-defined, lytic lesion was also observed radiographically in the sixth lumbar vertebra, it appeared as a focal hyperintense lesion on T1 weighted, T2 weighted, and GE images and showed focal enhancement on post-contrast T1 weighted images. She was euthanized owing to extreme pain and severe and progressive clinical signs; a plasmacytoma was histopthologically diagnosed. This report presents an unusual type of spinal tumor, plasmacytoma. MRI is a useful modality to evaluate the anatomic location and extension of spinal lesions.

• Journal of the Korean Society of Radiology
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• v.83 no.2
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• pp.432-438
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• 2022

Colonic angiosarcoma is an extremely rare and aggressive malignant tumor with poor prognosis. We report a case of colonic epithelioid angiosarcoma with colonic obstruction and rapidly progressive hepatic metastasis in a 44-year-old female. Abdominal CT revealed a heterogeneously enhancing irregular mass in the ascending colon, causing proximal bowel distension. The patient underwent surgery, and histopathological examination revealed a poorly differentiated carcinoma. A follow-up liver dynamic MRI after 4 months revealed newly developed diffusely scattered numerous small nodules in both hepatic lobes with peripheral and nodular marked arterial hyperenhancement, raising the suspicion of hepatic angiosarcoma. A pathologic second opinion was obtained, and additional immunohistochemistry revealed colonic epithelioid angiosarcoma. The patient showed progressive hepatic metastasis on follow-up abdominal CT after 6 months and died 8 months after initial diagnosis. We describe an educational case of colonic angiosarcoma, a rare malignant tumor, with rapidly progressive hepatic metastasis that showed radiologic findings suggestive of angiosarcoma and enabled a re-diagnosis for proper treatment and prognosis prediction.

• Journal of the Korean Society of Radiology
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• v.85 no.2
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• pp.421-427
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• 2024

Ectopic breast tissue can develop along the mammary ridge from the axilla to the groin, and the most common site is the axillae. Primary carcinoma of ectopic breast tissue is extremely rare. We report a rare case of a 61-year-old woman with a palpable mass in her left axilla who had a history of surgical excision of accessory breast tissue in the same area. Mammography (MMG), including axillary tail view, ultrasound (US), and breast MRI were performed. We evaluated the extent and characteristics of the microcalcifications in the axillary tail view. A US-guided biopsy was done, and histopathology revealed an invasive ductal carcinoma. Enhanced abdominal CT revealed multiple hepatic masses consistent with metastases, and the patient received palliative chemotherapy. Herein, we present a rare case of breast cancer arising from accessory breast tissue in the axilla, best appreciated on the axillary tail view of the patient's MMG.

• Journal of the Korean Society of Radiology
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• v.85 no.2
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• pp.381-393
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• 2024

Purpose Metabolic abnormalities in hepatic encephalopathy (HE) cause brain edema or demyelinating disease, resulting in symmetric regional cerebral edema (SRCE) on MRI. This study aimed to investigate the usefulness of the clustering analysis of SRCE in predicting the development of brain failure. Materials and Methods MR findings and clinical data of 98 consecutive patients with HE were retrospectively analyzed. The correlation between the 12 regions of SRCE was calculated using the phi (φ) coefficient, and the pattern was classified using hierarchical clustering using the φ² distance measure and Ward's method. The classified patterns of SRCE were correlated with clinical parameters such as the model for end-stage liver disease (MELD) score and HE grade. Results Significant associations were found between 22 pairs of regions of interest, including the red nucleus and corpus callosum (φ = 0.81, p < 0.001), crus cerebri and red nucleus (φ = 0.72, p < 0.001), and red nucleus and dentate nucleus (φ = 0.66, p < 0.001). After hierarchical clustering, 24 cases were classified into Group I, 35 into Group II, and 39 into Group III. Group III had a higher MELD score (p = 0.04) and HE grade (p = 0.002) than Group I. Conclusion Our study demonstrates that the SRCE patterns can be useful in predicting hepatic preservation and the occurrence of cerebral failure in HE.

• Journal of the Korean Society of Radiology
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• v.85 no.1
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• pp.240-246
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• 2024

Epithelioid angiosarcoma is a rare variant of angiosarcoma characterized by an epithelioid morphology that mimics carcinoma. Therefore, multicentric epithelioid angiosarcoma is easily misdiagnosed as bone metastasis from carcinoma and has an aggressive clinical course. Here, we present a rare case of a 61-year-old male with multicentric epithelioid angiosarcoma of the bone. Plain radiography, CT, and MRI revealed multiple osteolytic lesions in both femurs; some lesions showed soft tissue extension with cortical bone destruction. Interestingly, PET-CT revealed that the lesions were only distributed along the bones of the lower extremities, including the pelvic bones, femurs, and tibiae. Despite histological analysis initially suggesting metastatic carcinoma, after additional immunohistological staining, including that for vascular markers (CD31 and ERG), the final diagnosis was epithelioid angiosarcoma. A better understanding of the clinicoradiological features of this disease may help eliminate diagnostic confusion and provide better management.

• The Korean Journal of Nuclear Medicine
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• v.34 no.6
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• pp.445-455
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• 2000

Purpose: We evaluated the distribution of hypoperfusion in patients with traumatic brain injury (TBI) and the relationship of thalamic hypoperfusion to severity of cognitive and behavioral sequelae. Materials and Methods: Tc-99m ECD SPECT and MRI were performed in 103 patients (M/F=81/22, mean age $34.7{\pm}15.4$ yrs) from 0.5 to 55 months (mean 10.3 months) after TBI. The patients were divided into three groups showing no abnormalities (G1), focal (G2) and diffuse injury (G3) on MRI. Psychometric tests assessed 11 cognitive or behavioral items. In all patients, we evaluated the distribution of hypoperfused areas in SPECT, and in 57/103 patients, neuropsychological (NP) abnormalities in patients with thalamic hypoperfusion were compared with those of patients without thalamic hypoperfusion. Results: The perfusion deficits were most frequently located in the frontal lobe (G1, 42.3%: G2 34.5%: G3 33.3%), temporal lobe ($24{\sim}26%$) thalami ($21{\sim}22.4%$), parietal and occipital lobe (${\leq}10%$). Numbers of NP abnormalities in the cases of cortical hypoperfusion with or without concomitant thalamic hypoperfusion were following: the former $4.7{\pm}1.5$ and the latter $3.2{\pm}1.4\;in\;G1,\;5.0{\pm}1.1\;and\;4.8{\pm}1.2\;in\;G2,\;6.8{\pm}1.8\;and\;6.3{\pm}1.1\;in\;G3$, respectively. This difference according to thalamic hypoperfusion was significant in G1 (p=0.002), but was not significant in G2 or G3. Conclusion: SPECT in patients with TBI had demonstrated hypoperfusion mostly involving the frontal, temporal and thalami. In normal group on MRI, frontal hypoperfusion was more prominent than that of any other group, Furthermore in this group, SPECT could predict severity of NP outcome by concomitant thalamic hypoperfusion with cerebral cortical abnormalities.

• Journal of radiological science and technology
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• v.40 no.1
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• pp.109-120
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• 2017

In order to examine how Radiological Technologists perceive the oriental doctor's use of Medical Imaging Equipment, surveys were conducted for the members of the Korean Radiological Technologists Association. The total number of respondents were 515 and 481, with 34 insincere responses removed caused of nonvalidated answer. The results of the analysis are as follows. Although there were no statistical significance in the difference in perception by location of residence, work place, and educational background, respondents with higher education showed a tendency to agree on the use of comprehensive medical imaging equipment, but tended to oppose the use of special medical imaging equipment. Differences in perception by gender showed a greater negative perception toward the oriental doctor's use of medical imaging equipment by women than men. In particular, women showed more negative tendency for oriental doctor's use of special medical imaging equipment such as MRI, CT, and ultrasound equipment compared to men, and this was statistically significant. The difference in perception by age showed that the oriental doctor's use of medical imaging equipment was negative in the 20~30s, neutral in the 40~50s, and positive in the 60s, which were statistically significant. The difference in perception by work experience showed that the longer the work experience was, the more positive it was toward oriental doctor's use of medical imaging equipment. Specifically, the most favorable tendency was found with work experience of more than 30 years, which was statistically significant. The results of this study revealed the Radiological Technologists' perceptions on the oriental doctor's use of Medical Imaging Equipment and this can contribute to the direction of public health promotion in the future.