2.Water-Fat Imaging with Automatic Field Inhomogeneity Correction Using Joint Phase Magnitude Density Function at Low Field MRI.
Journal of the Korean Society of Magnetic Resonance in Medicine 2011;15(1):57-66
PURPOSE: A new inhomogeneity correction method based on two-point Dixon sequence is proposed to obtain water and fat images at 0.35T, low field magnetic resonance imaging (MRI) system. MATERIALS AND METHODS: Joint phase-magnitude density function (JPMF) is obtained from the in-phase and out-of-phase images by the two-point Dixon method. The range of the water signal is adjusted from the JPMF, and 3D inhomogeneity map is obtained from the phase of corresponding water volume. The 3D inhomogeneity map is used to correct the inhomogeneity field iteratively. RESULTS: The proposed water-fat imaging method was successfully applied to various organs. The proposed 3D inhomogeneity correction algorithm provides good performances in overall multi-slice images. CONCLUSION: The proposed water-fat separation method using JPMF is robust to field inhomogeneity. Three dimensional inhomogeneity map and the iterative inhomogeneity correction algorithm improve water and fat imaging substantially.
Joints
;
Magnetic Resonance Imaging
;
Water
3.Radiologic Analysis of Primary Hip Replacements on the Porous: Coated Acetabular Component
Ki Chan AHN ; Jang Suk CHOI ; Young Goo LEE ; Joon Beom BAE
The Journal of the Korean Orthopaedic Association 1995;30(4):861-867
Component fixation on the acetabular side is not as much of a problem because of the simpler geometry and loading configuration. It is generally accepted that hemispheric component design is preferable and immediate implant stability can be achieved by using screws or spikes in the porous coated implants. The authors reviewed 130 primary noncemented porouscoated, press fit acetabular component in 110 patients; 84 were AML (Anatomical Medullary Locking) and 46 were HarrisGalante acetabular component. Radiologic analysis at a minimum of 3 years(average 4.5 years) was done with special regards to the vertical and medial migration, screw size and numbers, change of the radiolucent line and its zone with its fate and acetabular cup angles on the acetabular component by the 2 observers. Progressive radiolucent line at the component-bone intersurface were found in 14 cases(11%), frequently located in zone I and zone I & II. No significant vertical, medial migration and change of the acetabular cup angle were found. No screw and spike failure had occurred. No component had to be revised because of loosening. As a whole, in our 3-years experience we report excellent results with porous coated acetabular component although it dose not ensure long-term sucess.
Acetabulum
;
Hip
;
Humans
4.The Effect of Ginseng Saponin on the Dopaminergic Neurons in the Parkinson's Disease Model in Mice.
Chang Ok KIM ; Ki Sok KIM ; Young Buhm HUH ; Byeong Woo AHN ; Beom Seok HAN ; Kwang Sik CHOI ; Ki Yul NAM ; Sang Woo JUHNG
Korean Journal of Pathology 1997;31(9):805-814
Saponin has been known to be a major antioxidant component in panax ginseng. Recent experimental study suggests that some antioxidant materials prevent Parkinson's disease caused by 1-methyl-4-phenyl-1,2,3,6- tetrahydropyridine (MPTP) in an animal model. The present study was performed to demonstrate the effect of ginseng saponins in the Parkinson's disease model induced by MPTP. To verify the effect of ginseng saponin on dopaminergic neurons in the mice brain, the tyrosine hydroxylase-immunoreactive (TH-ir) neurons were observed by immunohistochemical stain and immunoelectron microscopy (preembedding method). Also, in order to estimate the immunoreactivity of dopaminergic neuropils, they were quantified by image analysis. The number of TH-ir neurons of substantia nigra was significantly increased in the high-dose (0.46 mg/kg) ginseng saponin group compared with the MPTP injected group. The immunoreactivity of TH-ir neuropils in striatum was significantly increased in both high and low-dose (0.1 mg/kg) ginseng saponin groups compared with the MPTP injected group. In immunoelectron microscopic observation, TH-ir neurons of the control and both ginseng saponin injected group showed normal nuclei and well preserved cytoplasmic organelles. In the MPTP injected group, dying dopaminergic neurons showed destroyed nuclei and cytoplasmic organelles. These results suggest that ginseng saponin has a protective effect on the Parkinson's disease model induced by MPTP.
1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine
;
Animals
;
Brain
;
Cytoplasm
;
Dopaminergic Neurons*
;
Mice*
;
Microscopy, Immunoelectron
;
Models, Animal
;
Neurons
;
Neuropil
;
Organelles
;
Panax*
;
Parkinson Disease*
;
Saponins*
;
Substantia Nigra
;
Tyrosine
;
Tyrosine 3-Monooxygenase
5.Conductive Hearing Loss with Intact Tympanic Membrane: Two Cases of Fibrous Change of the Ossicles.
Jong Beom LIM ; Seong Ki AHN ; Sea Yuong JEON ; Jin Pyeong KIM
Korean Journal of Otolaryngology - Head and Neck Surgery 2003;46(12):1077-1079
In general, causes of conductive hearing loss with the intact tympanic membrane and external auditory canal are known as congenital anomaly of the ossicular chain, otosclerosis, and head trauma-induced ossicular discontinuity. But it may also occur due to fibrotic change by potential inflammation of the ossicular chain as a result of otitis media in the infancy or childhood. We report two cases of fibrous change of the ossicles by probable middle ear inflammation with a review of the related literature.
Ear Canal
;
Ear Ossicles
;
Head
;
Hearing Loss, Conductive*
;
Inflammation
;
Otitis Media
;
Otosclerosis
;
Tympanic Membrane*
6.Analysis of Nasalance according to Pattern of Phonation.
Cheol Min AHN ; Won Keun WOO ; Ki Hyung KIM ; Moon Sun SEO ; Beom Suk SEO
Korean Journal of Otolaryngology - Head and Neck Surgery 2005;48(7):899-903
BACKGROUND AND OBJECTIVES: Various phonation patterns yield various voice characteristics. Voice therapy using nasal stimulatory sounds seems to facilitate phonation in voice disodered patients. Under the hypothesis that nasalance may be influenced by the pattern of phonation, we studied the relationship between nasalance and voice disorders by observing abnormal supraglottic movements and vocol cord gaps in phonation. SUBJECTS AND METHOD: There were 143 patients who complained of voice problems and showed abnormal false vocal cord movements under stroboscopy. In addition to the four previously described types of MTD (muscle tension dysphonia), we described two more types of MTD (V: false vocal cord contracted posteriorly, VI: false vocal cord dilated laterally). We measured the vocal cord gaps in phonation and analyzed nasalance. RESULTS: Among those groups showing the pattern of false vocal cord (MTD 1, 2, 4), the vocal cord gaps in phonation were increased and nasalance was significantly decreased in MTD types, III and IV, and showed a tendency to decrease in MTD types, II and V, compared to the normal group. CONCLUSION: The supraglottis has a tendency to contract as the vocal cord gap in phonation increases, and this movement reduces nasalance.
Dysphonia
;
Humans
;
Phonation*
;
Stroboscopy
;
Vocal Cords
;
Voice
;
Voice Disorders
7.Two Cases of Peripheral Facial Nerve Neurilemmoma.
Jong Beom LIM ; Jin Pyeong KIM ; Seong Ki AHN ; Sea Yuong JEON
Korean Journal of Otolaryngology - Head and Neck Surgery 2002;45(10):1010-1013
Neurilemmomas are benign tumors that arise from the nerve sheath. Facial nerve neurilemmomas are uncommon, slow-growing neoplasms that occur anywhere along the course of the facial nerve. The majority of facial nerve neurilemmomas are intratemporal, with a few cases arising from the intraparotid portion. The clinical presentations are generally insidious and the nature of the disease depends on the location and extent of the tumor. They are difficult to diagnose preoperatively and are frequently misdiagnosed because of the variety of their clinical manifestations. Therefore, early and correct diagnosis and evaluation are necessary. Recently, we experienced two cases of facial nerve neurilemmoma with relatively good surgical result, involving the mastoid segment of the facial nerve and the main trunk of the facial nerve in the parotid gland. We reviewed the diagnosis, pathology, and treatement of this case, and report the cases with reviews of literature.
Diagnosis
;
Facial Nerve*
;
Mastoid
;
Neurilemmoma*
;
Parotid Gland
;
Pathology
8.Efficacy of a Combination with Pranlukast and Cetirizine in the Treatment of Allergic Rhinitis.
Dong Ju KIM ; Sea Young JEON ; Jin Pyeong KIM ; Seong Ki AHN ; Beom Gyu KIM
Korean Journal of Otolaryngology - Head and Neck Surgery 2004;47(9):863-867
BACKGROUND AND OBJECTIVES: It has been suggested that the combination of a leukotriene receptor antagonist with an antihistamine may have beneficial effects in the treatment of allergic rhinitis. The aim of this study were to evaluate the effects of combining a leukotriene receptor antagonist, pranlukast, and an antihistamine, cetirizine, to treat nasal symptoms of allergic rhinitis and the quality of life of the patients. SUBJECTS AND METHOD: Thirty-three patients with allergic rhinitis were enrolled in this study. The control group (n=12) received 5 mg cetirizine plus 120 mg pseudoephedrine twice a day while the study group (n=21) received 5 mg cetirizine plus 225 mg pranlukast twice a day. Patients completed a daily symptom-score list for nasal obstruction, rhinorrhea, sneezing, nasal itching during the 7-day treatment period. They also answered the quality of life questionnaire before and after the completion of 7-day treatment. RESULTS: There were significant improvements in the nasal symptoms after the treatment in the control and the study group. However, there was no significant difference between the control and the study group on the improvement of nasal symptom-scores except for the rhinorrhea symptom-score. There were significant improvements in the quality of life domain after the treatment in the control group and the study group. However, there was no significant difference between the control and the study group on the improvement in quality of life domain except for activity limitations. CONCLUSION: A combination of pranlukast and cetirizine is as effective as a combination of pseudoephedrine and cetirizine in treating allergic rhinitis. Therefore, a combination of pranlukast and cetirizine may be another therapeutic alternative for allergic rhinitis patients who are not tolerable of pseudoephedrine.
Cetirizine*
;
Histamine Antagonists
;
Humans
;
Hypersensitivity
;
Leukotrienes
;
Nasal Obstruction
;
Pruritus
;
Pseudoephedrine
;
Quality of Life
;
Surveys and Questionnaires
;
Receptors, Leukotriene
;
Rhinitis*
;
Sneezing
9.Clinical Analysis of Orbital Subperiosteal Abscesses as a Complication of Acute Sinusitis.
Jae Won KIM ; Seong Ki AHN ; Sea Yuong JEON ; Jin Pyeong KIM ; Beom Gyu KIM
Korean Journal of Otolaryngology - Head and Neck Surgery 2003;46(7):575-579
BACKGROUND AND OBJECTIVES: Orbital complications of sinusitis are uncommon but can result in significant morbidity if not appropriately managed. We have experienced 8 cases of orbital subperiosteal absces- ses (SPA) as a complication of acute sinusitis. The purposes of our study are to assess the clinical features, diagnosis, isolated bacteria, and therapeutic results. MATERIALS AND METHOD: Eight patients with acute rhinosinusitis and orbital SPA who had been treated between April 1989 and September 2002 were retrospectively studied with medical records and CT. RESULTS: The most common symptoms and signs were proptosis and opthalmoplegia, and five patients (62%) complained of ocular pain or periorbital erythema. Seven patients (87%) complained of diplopia. We carried out medical treatment in 4 cases and surgical intervention in 4 cases. All patients were cured without complications. Streptococcus intermedius was isolated from 1 case and peptostreptococcus species from another but there was no growth of bacteria in 2 cases. CONCLUSION: Conservative treatment with intravenous antibiotics, topical nasal decongestants are the appropriate initial management in orbital SPA. In cases of medially located SPA of orbit, we recommend endoscopic surgical drainage because it does not require an external incision and has less postoperative edema.
Abscess*
;
Anti-Bacterial Agents
;
Bacteria
;
Diagnosis
;
Diplopia
;
Drainage
;
Edema
;
Erythema
;
Exophthalmos
;
Humans
;
Medical Records
;
Nasal Decongestants
;
Orbit*
;
Peptostreptococcus
;
Retrospective Studies
;
Sinusitis*
;
Streptococcus intermedius
10.Biases in the Assessment of Left Ventricular Function by Compressed Sensing Cardiovascular Cine MRI
Jong Hyun YOON ; Pan Ki KIM ; Young Joong YANG ; Jinho PARK ; Byoung Wook CHOI ; Chang Beom AHN
Investigative Magnetic Resonance Imaging 2019;23(2):114-124
PURPOSE: We investigate biases in the assessments of left ventricular function (LVF), by compressed sensing (CS)-cine magnetic resonance imaging (MRI). MATERIALS AND METHODS: Cardiovascular cine images with short axis view, were obtained for 8 volunteers without CS. LVFs were assessed with subsampled data, with compression factors (CF) of 2, 3, 4, and 8. A semi-automatic segmentation program was used, for the assessment. The assessments by 3 CS methods (ITSC, FOCUSS, and view sharing (VS)), were compared to those without CS. Bland-Altman analysis and paired t-test were used, for comparison. In addition, real-time CS-cine imaging was also performed, with CF of 2, 3, 4, and 8 for the same volunteers. Assessments of LVF were similarly made, for CS data. A fixed compensation technique is suggested, to reduce the bias. RESULTS: The assessment of LVF by CS-cine, includes bias and random noise. Bias appeared much larger than random noise. Median of end-diastolic volume (EDV) with CS-cine (ITSC or FOCUSS) appeared −1.4% to −7.1% smaller, compared to that of standard cine, depending on CF from (2 to 8). End-systolic volume (ESV) appeared +1.6% to +14.3% larger, stroke volume (SV), −2.4% to −16.4% smaller, and ejection fraction (EF), −1.1% to −9.2% smaller, with P < 0.05. Bias was reduced from −5.6% to −1.8% for EF, by compensation applied to real-time CS-cine (CF = 8). CONCLUSION: Loss of temporal resolution by adopting missing data from nearby cardiac frames, causes an underestimation for EDV, and an overestimation for ESV, resulting in underestimations for SV and EF. The bias is not random. Thus it should be removed or reduced for better diagnosis. A fixed compensation is suggested, to reduce bias in the assessment of LVF.
Bias (Epidemiology)
;
Compensation and Redress
;
Diagnosis
;
Magnetic Resonance Imaging
;
Magnetic Resonance Imaging, Cine
;
Noise
;
Stroke Volume
;
Ventricular Function, Left
;
Volunteers