• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.27 no.3
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• pp.214-220
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• 2001

The clinical application of the three-dimensional radiographic technique had been limited to standard Broadbent-Bolton cephalometer with biplanar stereoradiography. We developed a new method for compensating the error of head position in ordinary non-biplanar cephalostat. It became to possible to use the three dimensional cephalogram commonly in clinical bases. 1. The method of methemetical compensation of head positioning error in non-biplanar condition was evaluated with dry skull. The error of the method of first and the second trial was $0.46{\pm}1.21$, $0.33{\pm}0.90mm$, which means the error of the head positioning correction in conventional cephalogram was within clinical acceptance. 2. The reproducibility of this system for clinical application was 0.54 mm ($-2.99{\sim}2.26mm$) which defines the absolute mean difference of the first and second trial. Compare to the The landmark identification error $1.2{\pm}1.6mm$, the error of the measurement was within the range of landmark identification error. The result indicates the adequate clinical accuracy of the computation of three-dimensional coordinates by compensation of the error of the head position in ordinary non-biplanar cephalostat.

• Journal of Korean Neurosurgical Society
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• v.30 no.9
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• pp.1079-1085
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• 2001

Objective : We analysed various surgical approaches and surgical results of 28 middle cranial base tumors for the purpose of selecting optimal surgical approach to the middle cranial base tumor. Methods : In this retrospective review, 28 patients, including 16 meningioma, 6 trigeminal neurinoma, 2 pituitary adenoma, 2 craniopharyngioma, 1 facial neurinoma, and 1 metastatic tumor, underwent surgical treatment using skull base technique. Of theses, 16 tumors were mainly confined to middle cranial fossae, 5 tumors with extension into both anterior and middle fossa, and 7 tumors with extension into both middle and posterior fossa. Tumors that confined to the middle cranial fossa or extended into the anterior cranial fossa were operated with modified pterional, orbitozygomatic or Dolen'c approach, and tumors that extended into the posterior cranial fossa were operated with anterior, posterior or combined transpetrosal approach. Completeness of tumor resection, surgical outcome, postoperative complication, and follow up result were studied. Results : Total tumor removal was achieved in 9 tumors of 10 tumors that did not extended to the cavernous sinus, and was achieved in 7 tumors of 8 tumors that extended to the lateral wall of the cavernous sinus. Of 10 tumors that extended to the venous channel of the cavernous sinus, only 2 were removed totally. Surgical outcome was excellent in 14 patients, good in 10, fair in 2 and poor in 2. There were no death in this series. Dumbell type tumor which extended into both middle and posterior fossae showed tendency of poor prognosis as compared with tumors that confined middle cranial fossa and extended into both anterior and middle cranial fossa. Postoperative dysfunctions were trieminal hypesthesia in 3, oculomotor nerve palsy in 2, abducens nerve palsy in 2, hemiparesis in 2, cerebellar sign in 1, facial palsy in 1 and hearing impairment in 1. Conclusion : Based on our findings and a review of the literature, we conclude that, when selecting the surgical approach to the middle cranial fossa tumors, the most important factors to be considered were exact location of the tumor mass and existence of the cavernous sinus invasion by tumor mass. We recommend modified pterional or orbitozygomatic approach in cases with tumors located anterior and middle cranial base, without cavernous sinus invasion. In cases with tumors invading into cavernous sinus, we recommend Dolen'c or orbitozygomatic approach. And in lateral wall mass and the cavernous sinus, it is preferred to approach the tumor extradurally. For the tumor involing with middle fossa and posterior fossa(dumbell type) a combined petrosal approach is necessary. In cases with cavernous sinus invasion and internal carotid artery encasement, we recommend subtotal resection of the tumor and radiation therapy to prevent permanent postoperative sequele.

• Progress in Medical Physics
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• v.10 no.1
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• pp.33-40
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• 1999

Purpose: To simulate and measure the signal intensity of various tissues near bone interface in 2D and 3D neurological MR images. Materials and Methods: In neurological proton density (PD) weighted images, every component in the head including cerebrospinal fluid (CSF), muscle and scalp, with the exception of bone, are visualised. It is possible to acquire images in 2D or 3D. A 2D fast spin-echo (FSE) sequence is chosen for the 2D acquisition and a 3D gradient-echo (GE) sequence is chosen for the 3D acquisition. To find out the signal intensities of CSF, muscle and fat (or scalp) for the 2D spin-echo(SE) and 3D gradient-echo (GE) imaging sequences, the theoretical signal intensities for 2D SE and 3D GE were calculated. For the 2D fast spin-echo (FSE) sequence, to produce the PD weighted image, long TR (4000 ms) and short TE$_{eff}$ (22 ms) were employed. For the 3D GE sequence, low flip angle (8$^{\circ}$) with short TR (35 ms) and short TE (3 ms) was used to produce the PD weighted contrast. Results: The 2D FSE sequence has CSF, muscle and scalp with superior image contrast and SNR of 39 - 57 while the 3D GE sequence has CSF, muscle and scalp with broadly similar image contrast and SNR of 26 - 33. SNR in the FSE image were better than those in the GE image and the skull edges appeared very clearly in the FSE image due to the edge enhancement effect in the FSE sequence. Furthermore, the contrast between CSF, muscle and scalp in the 2D FSE image was significantly better than in the 3D GE image, due to the strong signal intensities (or SNR) from CSF, muscle and scalp and enhanced edges of CSF. Conclusion: The signal intensity of various tissues near bone interface in neurological MR images has been simulated and measured. Both the simulation and imaging of the 2D SE and 3D GE sequences have CSF, fat and muscle with broadly similar image intensity and SNR's and have succeeded in getting all tissues about the same signal. However, in the 2D FSE sequence, image contrast between CSF, muscle and scalp was good and SNR was relatively high, imaging time was relatively short.

• The Journal of Korean Society for Radiation Therapy
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• v.17 no.1
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• pp.33-40
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• 2005

Purpose : We recently perform the latest radiotheraphy (3D conformal, IMRT,etc.) with the development of 3D CT planning technology. However, in case patients with breast cancer, it is difficult to acquire the CT image with the limitation of CT hole size and tilting of breast immobilization device. The Ewha Breast Device(EBD) was constructed to improve the problem in the treatment of patients with breast cancer and we are intend to introduce the procedure of the EBD construction in this study and compare the EBD with conventional breast device in the view point of usefulness. Materials and Methods : We have constructed the EBD with acryl, analyze the skull size with CT data, consider the skin folder in SCL field and evaluated the EBD usefulness from the view point of set-up reproducibility, dose distribution, skin reaction in comparison with conventional breast device. Results : In the case of patients set-up error analysis, the EBD is superior to conventional device in portal film repetition($\%$) check (80pt.), equal to that in simulation & CT image coincidence check(5pt.). There is no difference between the two systems in dose distribution and skin reaction in SCL field is better the EBD than conventional device. Conclusions : The construction of the EBD enable us to perform the latest radiotheraphy in breast treatments, relieve the pains in simulation, and reduce, the skin reaction. In the future, we expect that modification of the EBD is useful in treating for patients with breast cancer.

• The Korean Journal of Nuclear Medicine
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• v.30 no.4
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• pp.524-531
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• 1996

Purpose : To evaluate the pattern- of skeletal metastases and to classify the pattern of renal uptakes on bone scans in renal cell carcinoma. Materials and Methods : We reviewed the bone scans of 158 patients with RCC established pathologically. In order to identify individual scan lesion as a bone metastasis, we reviewed all available correlative radiological studies, follow-up bone scans, and biopsies for each lesion. The metastatic bone lesions were divided into seven anatomic regions; skull, spine, shoulder girdle, sternum, ribs, pelvis, and long bones of extremities. The individual scan lesions were divided into two groups as the pattern of uptakes, hot and cold lesion. In addition, the contours and uptakes of kidneys with RCC were classified into 6 groups ; normal uptake, photon-deficient lesion, faint up-take with enlargement, uneven uptake with enlargement, lateralization with crescentic shape, and increased uptake. Results : Twenty out of 158(12.7%) patients with RCC at varying stages showed 71 metastatic bone lesions at presentation and on follow- up bone scans. Nearly 80% of all metastatic lesions were in the axial skeleton with predominantly increased uptake of the radioactivity However a considerable number(22.5%) showed cold lesions on bone scan. A half of bone scans revealed abnormal uptake of involved kidney and much more(82.4%) in case of bone metastases. Two common patterns of abnormal renal uptake were photon-deficient lesion (50%) and faint uptake with enlargement(24.3%). In four patients with bone pain or pathologic fracture, bone scans were useful for the serendipitious localization of previously unrecognized primary lesion of RCC as well as for the detection of bone metastases from RCC. Conclusion : The understanding of the pat-terns of skeletal metastases and renal uptakes on bone scans in RCC is important for the useful information about primary lesion(RCC) as well as detection of bone metastases.

• Applied Microscopy
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• v.35 no.3
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• pp.135-152
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• 2005

Prefrontal cortex is a psychological and metaphysical cortex, which deals with feeling, memory, planning, attention, personality, etc. And it also integrates above-mentioned events with motor control and locomotor activities. Prefrontal cortex works as a highest CNS center, since the above mentioned functions are very important for one's successful life, and further more they are upgraded every moments through memory and learning. Many of these highest functions are supposed to be generated via forebrain basal nuclei (caudate nucleus, fundus striati nucleus, accumbens septi nucleus, septal nucleus, etc.). In this experiment, prefrontal efferent terminals within basal forebrain nuclei were ultrastructurally studied. Spraque Dawley rats, weighing $250{\sim}300g$ each, were anesthetized and their heads were fixed on the stereotaxic apparatus (experimental model, David Kopf Co.). Rats were incised their scalp, perforated a 3mm-wide hole on the right side of skull at the 11mm anterior point from the frontal O point (Ref. 13, Fig. 1), suctioned out the prefrontal cortex including cortex of the frontal pole, with suction instrument. Two days following the operations, small tissue blocks of basal forebrain nuclei were punched out, fixed in 1% glutaraldehyde-1% paraformaldehyde solution followed by 2% osmium tetroxide solutions. Ultrathin sections were stained with 1% borax-toluidin blue solution, and the stained sections were obserbed with an electron microscope. Degenerating axon terminals were found within all the basal forbrain nuclei. Numbers of degenerated terminals were largest in the caudate nucleus, next in order, in the fundus striati nucleus, in the accumbens septi nucleus, and the least in the septal nucleus. Only axospinous terminals were degenerated within the caudate nucleus and the fundus striati nucleus, and they showed the characters of striatal motor control system. Axodendritic and axospinous terminals were degenerated within the accumbens septi nucleus and the lateral septal nucleus, and they showed the characters of visceral limbic system. Prefrontal role in integrating the limbic system with the striatal system, en route basal forebrain nuclei, was discussed.

• Radiation Oncology Journal
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• v.16 no.3
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• pp.325-335
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• 1998

Purpose : Since the mid cranial fossa is composed of various thickness of bone, the tissue inhomogeneity caused by bone would produce dose attenuation in cobalt-60 gamma knife irradiation. The correction factor for bone attenuation of cobalt-60 which is used for gamma knife source is -3.5$\%$. More importantly, nearly all the radiosurgery treatment planning systems assume a treatment volume of unit density: any perturbation due to tissue inhomogeneity is neglected, This study was performed to confirm the bone attenuation in mid cranial fossa using gamma knife. Materials and Methods : Computed tomography was performed after Leksell stereotactic frame had been liked to the Alderson Rando Phantom (human phantom) skull area. Kodak X-omat V film was inserted into two sites of pituitary adenoma point and acoustic neurinoma point, and irradiated by gamma knife with 14mm and 18mm collimator. An automatic scanning densitometer with a 1mm aperture is used to measure the dose profile along the x and y axis. Results : Isodose curve constriction in mid cranial fossa is observed with various ranges. Pituitary tumor point is greater than acoustic neurinoma point (0.2-3.0 mm vs 0.1-1.3 mm) and generally 14 mm collimator is greater than 18mm collimator (0.4-3.0 mm vs. 0.2-2.2 mm) Even though the isodose constriction is found, constriction of 50$\%$ isodose curve which is used for treatment reference line does not exceed 1 mm. This range is too small to influence the treatment planning and treatment results. Conclusion : Radiosurgery planning system of gamma knife does not show significant error to be corrected without consideration of bone attenuation.

• Investigative Magnetic Resonance Imaging
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• v.2 no.1
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• pp.96-103
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• 1998

Purpose : To assess the clinical utility of turbo contrast-enhanced magnetic resonance angiography(CE MRA) in the evaluation of the aortic arch and its major branches and to compare the image quality of CE MRA among different coils used. Materials and Methods : Turbo three-phase dynamic CE MRA encompassing aortic arch and its major branches was prospectively performed after manual bolus IV injection of contrast material in 29 patients with suspected cerebrovascular diseases at 1.0T MR unit. the raw data were obtained with 3-D FISH sequence (TR 5.4ms, TE 2.3ms, flip angle 30, slab thickness 80nm, effective slice thickness 4.0mm, matrix size $100{\times}256$, FOV 280mm). Total data acquisition time was 4. to 60 seconds. We subjectively evaluated the imge quality with three-rating scheme : "good" for unequivocal normal finding, "fair" for relatively satisfactory quality to diagnose 'normal' despite intravascular low signal, and "poor" for equivocal diagnosis or non-visualization of the origin or segment of the vessels due to low signal or artifacts which needs catheter angiography. At the level of the carotid bifurcation, it was compared with conventional 2D-TOF MRA image. Overall image quality was also compared visually and quantitatively by measuring signal-to-noise ratios (SNRs) of the ascending aorta, the innominate artery and both common carotid arteries among the three different coils used(CP body array(n=12), CP neck array(n=9), and head-and-neck(n=8). Results : Demonstration of the aortic arch and its major branches was rated as "good" in 55% (16/29) and "fair" in 34%(10/29). At the level of the carotid bifurcation, image quality of turbo CE MRA was same as or better than conventional 2D-TOF MRA in 65% (17/26). Overall image quality and SNR were significantlygreater with CP body array coil than with CP neck array or head-and-neck coil. Conclusions : Turbo CE MRA can be used as a screening exam in the evaluation of the major branches of the aortic arch from their origin to the skull base. Overall imagequality appears to be better with CP body array coil than with CP neck array coil or head-and-neck coil.

• The korean journal of orthodontics
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• v.27 no.1
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• pp.129-140
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• 1997

Conventional cephalometrics have inherent errors because their evaluation is performed in two-dimension for threedimensional object. To compensate these errors, three-dimensional cephalograms - derivation of three-dimensional data from conventional lateral and postero-anterior cephalograms - were developed. In this study, the accuracy and precision of three dimensional cephalograms were determined by means of 10 linear and 12 angular measurements on 36 acrylic skull models and by the comparison of conventional lateral cephalograms. The results were as follows 1. Mean difference between three-dimensional cephalograms and actual models in linear measurements was $0.94{\pm}0.62mm$ and mean rate of magnification of three-dimensional cephalograms was $100.31{\pm}0.91%$. There were no statistically significant differences between three-dimensional cephalograms and actual models in linear measurements(${\alpha}=0.1$). 2. Mean difference between conventional lateral cephalograms and actual models in linear measurements was $6.44{\pm}1.48mm$ and mean rate of magnification of lateral cephalograms was $106.99{\pm}1.45%$. There were statistically significant differences between lateral cephalograms and actual models in linear measurements(P<0.005). 3. Mean difference between three-dimensional cephalograms and actual models in angular measurements was $1.22{\pm}0.82^{\circ}$ and mean rate of magnification of three-dimensional cephalograms was $105.71{\pm}12.07%$. There were no statistically significant differences between three-dimensional cephalograms and actual models in angular measurements(${\alpha}=0.1$). 4. Mean difference between conventional lateral cephalograms and actual models in angular measurements was $1.70{\pm}0.94^{\circ}$ and mean rate of magnification of lateral cephalograms was $106.35{\pm}15.70%$. There were no statistically significant differences between lateral cephalograms and actual models in angular measurements(${\alpha}=0.1$). There were similarity between three-dimensional and lateral cephalograms in angular measurements.

• Korean Journal of Ichthyology
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• v.6 no.2
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• pp.132-159
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• 1994

The taxonomic revision of the family Congridae was made based on the specimens collected from the south-western coasts of the Korea from June 1988 to Oct. 1993. The family Congridae was classified into 8 species belonging to 6 genera. based on the external and internal morphological characters : Anago anago, Ariosoma anagodies, Ariosoma shiroanago shiroanago, Conger myriaster, Conger japonicus, Gnathophis nystromi nystromi, Rhechias retrotincta and Uroconger lepturus. Among the species reported as the congrid eels from Korea until now, four species were transferred into different generic or specific name Conger flavirostris into Ariosoma anagoides ; Astroconger myriaster into Conger myriaster ; Congrina retrotincta into Rhechias retrotincta and Rhynchocymba nystromi into Gnathophis nystromi nystromi. A Korean congrid eel, Ariosoma shiroanago shiroanago, was reported for first time in Korea. Intergeneric characters of the family Congridae were the form of the lateralline scales, the state of the tip of tail, the segmented state of the dorsal and anal fin rays, the existance of the supraoccipital bone and of lateral ethmoid process of the skull, the origin of dorsal fin and the forms of upper labial flange. The interspecific classification was made according to the characters such as the numbers of sensory pores of head part and in front of vent, teeth rows and numbers of upper and lower jaw, the numbers of vertebrae, the body color, the shapes of the head part, the color of intestine, the size of eye, the structure of air bladder and the number of branchiostegal rays. A new key on the taxonomical characteristics to the genera and species of the family Congridae has been estabilished and their distribution in Korea is described.