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Lee J.-H.,Korea Veterans Hospital | Lee J.-H.,Hallym University | Lee H.-K.,Soonchunhyang University | Cho J.-H.,Hallym University | Cheon M.,Korea Veterans Hospital
Journal of Magnetics | Year: 2014

The purpose of the study is to investigate how uptake counts of 201Tl of radioisotopes in the human body could change, when taking computed tomography and magnetic resonance imaging right after injecting contrast media. 201Tl radioisotope substances of iodine contrast medium, which is a computed tomography contrast medium, and paramagnetic contrast medium, which is an magnetic resonance imaging contrast medium, were used as study materials. First, 201Tl was put into 4 cc of normal saline in test tube, and then a computed tomography contrast medium of Iopamidol® or Dotarem®, was put into 2 cc of normal saline in test tube. An magnetic resonance imaging contrast medium of Primovist® or Gadovist® was also put into 2 cc of normal saline in test tube. Each contrast medium was distributed to make 201Tl as 3 mCi, with a total of 4 cc. Gamma camera, low energy high resolution collimator, and pinhole collimator were used to obtain images. The uptake count of 201Tl was measured with 1000 frames of images, and obtained after 10 times of repetition. This study revealed that the use of Gadovist®, which is an magnetic resonance imaging contrast medium, showed the smallest number of uptake count, after measuring 201Tl uptake count by low energy high resolution collimator. On the other hand, the use of Iopamidol®, which is a computed tomography contrast medium, showed the biggest difference in uptake count, when measuring 99mTc uptake count by Pinhole collimator. When examining with gamma camera, using contrast medium and 201Tl, identifying the changes of uptake count is very important for improving the value of diagnosis. © The Korean Magnetics Society. All rights reserved.


Cho J.-H.,Hallym University | Lee J.-H.,Hallym University | Lee J.-H.,Korea Veterans Hospital | Park C.-S.,Hallym University | And 4 more authors.
Journal of Magnetics | Year: 2014

The purpose of this study is to figure out how uptake counts of technetium (99mTc) among radioisotopes in the human body are affected if computed tomography (CT), magnetic resonance imaging (MRI) and isotope examination are performed consecutively.99mTc isotope material, iodinated contrast media for CT and paramagnetic contrast media for magnetic resonance (MR) were used as experimental materials. First,99mTc was added to 4 cc normal saline in a test tube. Then, 2 cc of CT contrast media such as Iopamidol® and Dotarem® were diluted with 2 cc normal saline, and 2cc of MRI contrast media such as Primovist® and Gadovist® were diluted with 2 cc normal saline. Each distributed contrast media was a total of 4 cc and included 10m Ci of99mTc. A gamma camera, a LEHR (Low energy high resolution) collimator and a pin-hole collimator were used for image acquisition. Image acquisition was repeated a total of 6 times and 120 frames were obtained and uptake counts of99mTc were measured (from this procedure). In this study, as a result of measuring the uptake counts of99mTc using the LEHR collimator, the uptake counts were less measured in all contrast media than normal saline as a reference. In particular, the lowest uptake counts were measured when Gadovist®, contrast media for MRI, was used. However, the result of measuring the uptake counts of99mTc using the pin-hole collimator showed higher uptake counts in all contrast media, except for Iopamidol®, than normal saline as a reference. The highest uptake counts were measured particularly when Primovist®, contrast media for MRI, was used. In performing the gamma camera examination using contrast media and99mTc, it is considered significant to check the changes in the uptake counts to improve various diagnosis values. © The Korean Magnetics Society. All rights reserved.


Bae J.-H.,Inje University | Bae J.-H.,Korea University | Paik N.H.,Inje University | Park G.-W.,Inje University | And 5 more authors.
Arthroscopy - Journal of Arthroscopic and Related Surgery | Year: 2013

Purpose: The purpose of this study was to determine the accuracy, sensitivity, specificity, and predictive values of a single event of painful popping in the presence of a posterior root tear of the medial meniscus in middle-aged to older Asian patients. Methods: We conducted a retrospective review of medical records of 936 patients who underwent arthroscopic surgeries for an isolated medial meniscus tear between January 2000 and December 2010. There were 332 men and 604 women with a mean age of 41 years (range, 25 to 66 years). The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of a painful popping sensation for a posterior root tear of the medial meniscus were calculated. Results: Arthroscopy confirmed the presence of posterior root tears of the medial menisci in 237 of 936 patients (25.3%). A single event of a painful popping sensation was present in 86 of these 936 patients (9.1%). Of these 86 patients with a painful popping sensation, 83 (96.5%) were categorized as having an isolated posterior root tear of the medial meniscus. The positive predictive value of a painful popping sensation in identifying a posterior root tear of the medial meniscus was 96.5%, the negative predictive value was 81.8%, the sensitivity was 35.0%, the specificity was 99.5%, and the diagnostic accuracy was 77.9%. Conclusions: A single event of painful popping can be a highly predictive clinical sign of a posterior root tear of the medial meniscus in the middle-aged to older Asian population. However, it has low sensitivity for the detection of a posterior root tear of the medial meniscus. Level of Evidence: Level IV, therapeutic case series. © 2013 by the Arthroscopy Association of North America.


Choi Y.-S.,Hallym University | Cho J.-H.,Hallym University | Namgung J.-S.,Hallym University | Namgung J.-S.,Korea Veterans Hospital | And 4 more authors.
Journal of the Korean Physical Society | Year: 2013

This study performed a comparative analysis of cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT), and mean time-to-peak (TTP) obtained by changing the region of interest's (ROI) anatomical positions, during CT brain perfusion. We acquired axial source images of perfusion CT from 20 patients undergoing CT perfusion exams due to brain trauma. Subsequently, the CBV, CBF, MTT, and TTP values were calculated through data-processing of the perfusion CT images. The color scales for the CBV, CBF, MTT, and TTP maps were obtained using the image data. Anterior cerebral artery (ACA) was taken as the standard ROI for the calculations of the perfusion values. Differences in the hemodynamic average values were compared in a quantitative analysis by placing ROI and the dividing axial images into proximal, middle, and distal segments anatomically. By performing the qualitative analysis using a blind test, we observed changes in the sensory characteristics by using the color scales of the CBV, CBF, and MTT maps in the proximal, middle, and distal segments. According to the qualitative analysis, no differences were found in CBV, CBF, MTT, and TTP values of the proximal, middle, and distal segments and no changes were detected in the color scales of the the CBV, CBF, MTT, and TTP maps in the proximal, middle, and distal segments. We anticipate that the results of the study will useful in assessing brain trauma patients using by perfusion imaging. © 2013 The Korean Physical Society.


Cho J.-H.,Hallym University | Lee H.-K.,Soonchunhyang University | Kim H.-J.,Soonchunhyang University | Heo Y.-C.,Hallym University | And 4 more authors.
Japanese Journal of Radiology | Year: 2014

Purpose: The purpose of this study was to use various radiation-permeable and radiation-impermeable materials, used to facilitate the observation of a lesion during a rectal computed tomography (CT) scan, in order to determine the best material to use.Materials and methods: In regard to the study method, the radiation-permeable and radiation-impermeable materials of physiological saline, methylcellulose, contrast medium, ultrasound gel, and air were used to perform scanning with scan parameters that were used in general abdominal scanning. The GSI mode was used for material analysis.Results: According to the results of the phantom study, the average CT value was 25.5 ± 5.9 HU for physiological saline, 77.6 ± 7.3 HU for methylcellulose, 3,070 ± 0.1 HU for contrast medium, 74.1 ± 11.9 HU for ultrasound gel, and −954.1 ± 10.3 HU for air. According to the analysis of materials by energy, contrast medium and physiological saline showed a dramatic decrease in the CT value as energy increased. Methylcellulose showed a gradual decrease in CT value, whereas air showed a small change in CT value according to the graph.Conclusions: Out of these materials, methylcellulose had the advantage of reducing discomfort in patients, and was more convenient for examiners before and after the rectal CT scan. © Japan Radiological Society 2014.


Jin Y.-J.,University of Ulsan | Shim J.H.,University of Ulsan | Chung Y.-H.,University of Ulsan | Kim J.A.,University of Ulsan | And 7 more authors.
Journal of Clinical Gastroenterology | Year: 2012

Goals:: We intended to analyze the relationship between specific human leukocyte antigen (HLA)-DRB1 alleles and development of hepatocellular carcinoma (HCC) in chronic hepatitis B (CHB) patients. Study:: A database of 468 consecutive CHB patients who received lamivudine for more than 12 months between July 1996 and February 2011 was retrospectively analyzed. Sera and buffy coats samples were obtained between April 2008 and April 2010. Six-digit HLA-DRB1 genotyping was performed with sequence-based typing. Serum α fetoprotein levels and ultrasonography or computed tomography image studies were assessed every 3 to 6 months for surveillance of HCC. Results:: At baseline, median age was 43 years (range, 16 to 71) [male: 359 (76.7%); HBeAg positivity: 385 (82.3%)]. Among the 27 HLA-DRB1 alleles identified, HLA-DRB1*090102, *080302, and *070101 were the most frequent (>10%). HCC was diagnosed in 36 (7.7%) patients during the median follow-up of 69 months. The frequency of the HLA-DRB1*140101 allele was 9.0% and significantly higher in patients of the HCC group than those of the non-HCC group (19.4 vs. 8.1%, P=0.014). The 2-year, 4-year, and 6-year cumulative rates of HCC development were markedly higher in patients with HLA-DRB1*140101 than those without HLA-DRB1*140101 (2.4, 8.2, and 25.1% vs. 1.9, 4.7, and 7.4%, respectively, P=0.011). No other HLA-DRB1 alleles were associated with HCC development. Baseline clinical characteristics did not differ between patients with and without HLA-DRB1*140101. Conclusions:: The HLA-DRB1*140101 allele may be potentially associated with increased risk of HCC development in CHB patients, irrespective of the replicative activity of hepatitis B virus and antiviral responsiveness. © 2012 by Lippincott Williams & Wilkins.


Kim S.-B.,Kyung Hee University | Lee J.-H.,Korea Veterans Hospital | Lee J.-H.,Soonchunhyang University | Ahn J.-O.,Soonchunhyang University | Cho J.-H.,Hallym University
Journal of Magnetics | Year: 2015

The purpose of the study was to identify how isotope and magnetic resonance imaging (MRI) contrast media impact on noise to computed tomography (CT) examination. For the study, divide the phantoms to two groups: 1) saline, saline + different kinds of contrast agent without 99mTc administration; 2) 99mTc administration: saline, saline + different kinds of contrast agent with 99mTc administration. CT contrast agent was used for Iopamidol® and Dotarem. And MRI contrast agent was used for Primovist® and Gadovist®. To obtain an image, we used CT scanner. With an obtained image, we set the 1 cm2 region of interest in the middle of bottle to measure the noise and CT number. As a result, there was no difference in CT number before and after inserting 99mTc into all contrast media including Normal Saline. However, when it comes to Noise, there was a difference before and after inserting 99mTc into every contrast media except MRI contrast media such as Primovist® and Gadovist®. © The Korean Magnetics Society. All rights reserved.


Jin Y.-J.,University of Ulsan | Shim J.H.,University of Ulsan | Chung Y.-H.,University of Ulsan | Kim J.A.,University of Ulsan | And 7 more authors.
Digestion | Year: 2011

Background/Aims: We intended to evaluate the association between specific human leukocyte antigen (HLA)-DRB1 gene polymorphism and antiviral response to lamivudine (LAM) therapy in chronic hepatitis B (CHB) patients. Methods: Six-digit HLA-DRB1 genotypes were determined using sequence-based typing in 334 CHB patients initially treated with LAM for at least 12 months. Antiviral response was evaluated every 3-6 months during LAM therapy. Results: Median age of the subjects was 43 years (range, 16-72). Median duration of LAM therapy was 69 months (range, 13-140). Median baseline serum hepatitis B virus (HBV DNA) level was 7.0 log 10 copies/ml (range, 5.5-9.1). At 12 months of LAM therapy, serum HBV DNA was undetectable by solution hybridization method in 308 (88%) patients. Among 25 HLA-DRB1 alleles identified, HLA-DRB1*090102, *080302, and *070101 were the most frequent alleles (>10%). HLA-DRB1*010101 was identified in 5.4% (18/334). The frequency of the HLA-DRB1*010101 allele was significantly lower in patients with virological response at 12 months of LAM therapy than in patients without it (4.2 vs. 19.2%, p = 0.025). The other HLA-DRB1 alleles were not associated with virological response. HBeAg loss/seroconversion and alanine aminotransferase normalization were not associated with HLA-DRB1 alleles. Conclusion: The HLA-DRB1*010101 allele is closely associated with poor virological response to initial LAM therapy in CHB patients. Copyright © 2011 S. Karger AG, Basel.


Lee J.-H.,Korea Veterans Hospital | Lee J.-H.,Hallym University | Lee H.-K.,Soonchunhyang University | Cho J.-H.,Hallym University
Applied Magnetic Resonance | Year: 2015

The purpose of the study is to find out the changes of the signal-to-noise ratio (SNR) of magnetic resonance imaging (MRI) when performing MRI, computed tomography (CT), and isotope examination using99mTc. For the study, divide the phantoms into two groups: (1) saline, saline + different kinds of contrast agent without99mTc administration; (2)99mTc administration: saline, saline + different kinds of the contrast agent with99mTc administration. The CT contrast agent was used for Iopamidol® and Dotarem. And MRI contrast agent was used for Primovist® and Gadovist®. To obtain image, we used 3.0 T MR System, and obtained T1 and T2 images. Using obtained image, we compared an average value of SNR of T1 and T2 before and after distributing99mTc. As a result, SNR in T1 images had a significant difference before and after putting99mTc to every contrast media except normal saline. Also SNR in T2 mages had a significant difference before and after putting99mTc in every contrast media except Gadovist®. © 2015, Springer-Verlag Wien.

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