1.The value of 2-D echocardiography in diagnosis of CHD.
Sang Kyung YUN ; Young Woon BAEK ; Hyun Ki JUNG
Journal of the Korean Pediatric Society 1991;34(5):662-667
No abstract available.
Diagnosis*
;
Echocardiography*
2.The experiments on the infectivity to mice of the Ascaris eggs irradiated with Cobalt(60).
Ok Ran LEE ; Baek Hyun YUN ; Won Young CHOI
The Korean Journal of Parasitology 1970;8(3):90-95
In order to find out a valuable control measure for soil-transmitted parasties, the infectivity in mice of Ascaris eggs irradiated with Cobalt(60) were examined. The results were summarised as follows. In vitro, Ascaris eggs irradiated with larger doses of Cobalt(60) developed poorly, and no difference was found between fresh eggs and those cultured for a few days. Ascaris eggs irradiated with doses of 200,000 rad. developed at the rate of 90 percent after 4 weeks, whereas those irradiated with 1,000,000 rad. developed 28 percent. Ascaris eggs irradiated with Cobalt(60) after 2 weeks of culture were poor in development compared with those of 4 week culture. Eggs cultured for 5 weeks showed weaker infectivity in mice than those cultured for 8 weeks. In the control groups, the infectivity in mice of Ascaris eggs was remained the same between 5 and 8 weeks. The minimum dose of Cobalt(60) irradiation effective for preventing infectivity in mice was estimated to be 200,000 rad.
parasiotology
;
radiology
;
prevention
;
Ascaris suum
;
nematode
;
Cobalt(60)
;
irradiation
3.Correction of facial asymmetry using various vascularized free tissue transfers.
Yong Hyun YUN ; Rong Min BAEK ; Jae Ock OH ; Joon CHOE ; Se Min BAEK
Journal of the Korean Society of Plastic and Reconstructive Surgeons 1993;20(5):1014-1022
No abstract available.
Facial Asymmetry*
4.Correction of the buttonhole deformity.
Moon Sang CHUNG ; Jun Oh YUN ; Kwang Hyun LEE ; Goo Hyun BAEK ; Sug Jun KIM
The Journal of the Korean Orthopaedic Association 1993;28(3):1041-1050
No abstract available.
Congenital Abnormalities*
5.Spontaneous Testicular Hemorrhagic Necrosis Masquerading as a Testis Tumor .
Seung Hyun BAEK ; Jun Baek PARK ; Yun Hyung JANG ; Yeon Won PARK ; Jin Hyung LEE ; Seung Ki MIN
Korean Journal of Urology 2004;45(9):962-965
Spontaneous testicular hemorrhagic necrosis is a rare disease usually associated with testicular torsion. Partially involved and suspicious testis tumor cases are also defined from orchiectomy specimens. Herein, a spontaneous hemorrhagic necrosis, without any testicular torsion, but with involvement of the whole testicle and epididymis, is reported. A 21 year old patient, who presented with a painless left testicular enlargement of several days duration was believed, based on physical examination, ultrasonography and elevation of serum LDH, to have a testicular tumor. Diagnosis was made only after radical orchiectomy and histopathological examination.
Diagnosis
;
Epididymis
;
Hemorrhage
;
Humans
;
Male
;
Necrosis*
;
Orchiectomy
;
Physical Examination
;
Rare Diseases
;
Spermatic Cord Torsion
;
Testis*
;
Ultrasonography
;
Young Adult
6.A comparison of the efficiency of the three egg count techniques.
Ok Ran LEE ; Won Koo LEE ; Baek Hyun YUN ; Kyu Myon LEE
The Korean Journal of Parasitology 1972;10(2):90-94
Usually egg count technique has been employed to know the intensity of infestation of human intestinal helminths and to elucidate the effects of anthelmintics. Comparing the three egg count methods - Stoll's egg dilution method, Beaver's direct smear method and FHK counting board method - the authors reached the following results: As the result of application of the three methods to 75 Ascaris egg positives and 95 Trichocephalus egg positives, in the case of Ascaris eggs, the egg detection rate was 99 per cent by Stoll's method, 97 per cent by Beaver's method and was lowest by FHK method at 79 percent. Meanwhile, in Trichocephalus eggs, Stoll's method revealed 92 percent, Beaver's method 95 percent, and FHK method 95 percent, there being no noticeable differences. With regard to EPG, in counting Ascaris eggs, Stoll's method showed a value closest to the actual number of eggs, and the value revealed by FHK method was smaller than the actual number. As the result of comparing the coefficiencies of variation of the three egg counting methods, both in Ascaris eggs and Trichocephalus eggs, the FHK method showed the smallest, followed by Stoll's method and Beaver's method.
parasitology-helminth-nematoda
;
Ascaris lumbricoides
;
Trichuris trichiura
;
diagnosis
7.Two Cases of Fetal Bilateral Renal Agenesis.
Jong Kuk BAEK ; Jung Hwan HYUN ; Yun Seok CHOI ; Tae Sang KIM ; Ik Su KIM
Korean Journal of Obstetrics and Gynecology 1999;42(9):2122-2125
Fetal bilateral renal agenesis is a lethal congenital anomaly. An early and reliable prenatal diagnosis is extremely important as it may offer options for pregnancy termination as early as possible. The criteria for the ultrasonographic diagnosis of bilateral renal agenesis are severe oligohydramnios, nonvisualization of the bladder, and the empty renal fossa. However, severe oligohydramnios makes it difficult to diagnose the disease because of poor sonographic resolution. We present two cases of bilateral renal agenesis, one is diagnosed by ultrasonography after amnioinfusion at 24 weeks gestation, the other is diagnosed postnatally after term delivery.
Diagnosis
;
Female
;
Oligohydramnios
;
Pregnancy
;
Prenatal Diagnosis
;
Ultrasonography
;
Urinary Bladder
8.Fine structure of Toxoplasma gondii.
Sang Hee HAN ; Won Young CHOI ; Baek Hyun YUN ; Young Kun DEUNG
The Korean Journal of Parasitology 1971;9(2):61-68
The importance of Toxoplasma gondii in human disease stimulated a number of electron microscope studies on the structure of this protozoan parasite. Gustafson et al. first studied the fine structure by means of thin sections in 1954. Many other papers havs subsequantly appeared. It is well known that Toxoplasma gondii has two stages in its life cycle-the proliferative forms and the cyst. The purpose of the electron microscopical work reported here was to study the fine structure of Toxoplasma gondii with recent techniques clarifying the correlation between the proliferative forms and cyst. RH strain and KM strain as proliferative forms on the one hand and Beverley strain as a cyst form of Toxoplasma gondii on the other hand were used throughout this study. The conoid, toxoneme, nucleus, nucleolus, osmiophilic granules, mitochondria and vacuoles were found in RH strain as wsll as in KM strain and Beverley strain. The endoplasmic reticulum was found in the cytoplasm of RH strain and KM strain. It was better developed in KM strain than in RH strain. The outside contour of the organism of Beverley strain was somewhat irregular and toxoneme of this organism was better developed than in the other two strains. Vacuoles were found in RH strain, KM strain and Beverley strain. Furthermore, tube-like bodies were observed in the vacuoles of the organism of RH strain. In KM strain, two organisms of the same size were demonstrated in the leucocytes. It was presumed that they were products of longitudinal division.
parasitology-protozoa- Toxoplasma gondii
;
electron microscopy
9.Reduced Scan Time in Multi-Echo Gradient Echo Imaging Using Two-Stage Neural Network
Ji-Su YUN ; Jong-Yun BAEK ; Dong-Hyun KIM
Investigative Magnetic Resonance Imaging 2024;28(4):174-183
Purpose:
Multi-echo gradient echo (mGRE) images are used to acquire and analyze multiple echo signals. As the number of acquired echoes increases, more information on the voxel decay changes can be obtained, facilitating myelin water fraction (MWF) mapping.However, an increase in the acquired echoes leads to an increase in scan time. In this study, we developed a workflow to reduce the scan time using a two-stage neural network approach, which extrapolates additional echo images using mGRE data.
Materials and Methods:
In Stage 1, a pseudo-T1 map was estimated using a U-net network combined with a simple signal model to correct the bias between two mGRE acquired with different scan parameters. The pseudo-T1 map was used to generate an initial echo time (TE) image from the mGRE images. In Stage 2, subsequent TE images were predicted from the initial echo image generated using a trained prediction network. The results were quantitatively compared with those obtained using a fitting algorithm. The MWF mapping results were then compared.
Results:
The proposed model exhibited better root mean square error, structural similarity index measure, and peak signal-to-noise ratio, as well as a higher correlation with the MWF analysis compared to the fitting algorithm.
Conclusion
These results demonstrate that the proposed network can effectively reduce the scan time for mGRE image acquisition.
10.Reduced Scan Time in Multi-Echo Gradient Echo Imaging Using Two-Stage Neural Network
Ji-Su YUN ; Jong-Yun BAEK ; Dong-Hyun KIM
Investigative Magnetic Resonance Imaging 2024;28(4):174-183
Purpose:
Multi-echo gradient echo (mGRE) images are used to acquire and analyze multiple echo signals. As the number of acquired echoes increases, more information on the voxel decay changes can be obtained, facilitating myelin water fraction (MWF) mapping.However, an increase in the acquired echoes leads to an increase in scan time. In this study, we developed a workflow to reduce the scan time using a two-stage neural network approach, which extrapolates additional echo images using mGRE data.
Materials and Methods:
In Stage 1, a pseudo-T1 map was estimated using a U-net network combined with a simple signal model to correct the bias between two mGRE acquired with different scan parameters. The pseudo-T1 map was used to generate an initial echo time (TE) image from the mGRE images. In Stage 2, subsequent TE images were predicted from the initial echo image generated using a trained prediction network. The results were quantitatively compared with those obtained using a fitting algorithm. The MWF mapping results were then compared.
Results:
The proposed model exhibited better root mean square error, structural similarity index measure, and peak signal-to-noise ratio, as well as a higher correlation with the MWF analysis compared to the fitting algorithm.
Conclusion
These results demonstrate that the proposed network can effectively reduce the scan time for mGRE image acquisition.