• Journal of the Korean Society of Radiology
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• v.13 no.4
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• pp.503-508
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• 2019

In short a binary value according to a change in the tube voltage by using one of VOLUME AXIAL MODE of scanning techniques of chest CT image quality evaluation in order to obtain high image and to present the appropriate tube voltage. CT instruments were GE Revolution (GE Healthcare, Wisconsin USA) model and Phantom used Pediatric Whole Body Phantom PBU-70. The test method was examined in Volume Axial mode using the pediatric protocol used in the Y university hospital of mass-produced material. The tube voltage was set to 70kvp, 80kvp, 100kvp, and mAs was set to smart mA-ODM. The mean SNR difference of the heart was $-4.53{\pm}0.26$ at 70 kvp, $-3.34{\pm}0.18$ at 80 kvp, $-1.87{\pm}0.15$ at 100 kvp, and SNR at 70 kvp was about -2.66 higher than 100 kvp and statistically significant (p<0.05) In the Lung SNR mean difference analysis, $-78.20{\pm}4.16$ at 70 kvp, $-79.10{\pm}4.39$ at 80 kvp, $-77.43{\pm}4.72$ at 100 kvp, and SNR at 70 kvp at about -0.77 higher than 100 kvp were statistically significant. (p<0.05). Lung CNR mean difference was $73.67{\pm}3.95$ at 70 kvp, $75.76{\pm}4.25$ at 80 kvp, $75.57{\pm}4.62$ at 100 kvp and 20.9 CNR at 80 kvp higher than 70 kvp and statistically significant (p<0.05) At 100 kvp of tube voltage, the SNR was close to 1 while maintaining the quality of the heart image when 70 kvp and 80 kvp were compared. However, there is no difference in SNR between 70 kvp and 80 kvp, and 70 kvp can be used to reduce the radiation dose. On the other and, CNR showed an approximate value of 1 at 70 kvp. There is no difference between 80 kvp and 100 kvp. Therefore, 80 kvp can reduce the radiation dose by pediatric chest CT. In addition, it is possible to perform a scan with a short scan time of 0.3 seconds in the volume axial mode test, which is useful for pediatric patients who need to move or relax.

• Journal of Korean Neurosurgical Society
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• v.30 no.5
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• pp.586-591
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• 2001

Objective : Transseptal or sublabial transsphenoidal surgery has been standard teatment for pituitary tumors for decades. However, as an alternative to this surgery endonasal endoscopic technique has been reported with encouraging results. We have started endoscopy-assisted transsphednoidal surgery from May 1998. In this paper we analyzed the methods, outcome, advantage and disadvantage of this surgical approach for the purpose of planning optimal treatment of pituitary tumors. Methods : This study consisits of 13 cases of pituitary tumors who were treated by endoscopy-assisted transsphenoidal surgery using one nostril from May 1998 to July 1999. Mean follow up period was 12.9 months. Results : There was no septal or sublabial incision and little surgical damage to nasal structure. With this technique, rapid surgical approach and short hospital day were possible, being 3-6 days in patients without CSF leakage. Using various angled endoscope, good surgical view was obtained. Initially it was difficult to use various instruments in narrow nasal cavity, but became feasible after several procedures. Among 13 cases, total removal was possible in 11 cases. One of two cases in whom tumor was incompletely removed underwent gamma-knife radiosurgery and second underwent reoperation through subfrontal approach. There were 6 cases of hormone secreting tumors and hormonal remission was achived in all of these cases. Postoperative complications were CSF leakage(6 cases), diabetes insipidus(2 cases) and panhypopituitarysm(1 case). Lumbar drainage was done in all cases of CSF leakage. Conclusion : The advantage of endoscopy-assisted transsphenoidal surgery are rapid surgical approach, low postoperative morbidity, short hospital day and good surgical view. The disadvantage of this appoach are difficulty in manupulating various instruments in narrow nostril and difficulty in distance perception but these problems can be overcome by practice and using stereoscopic endoscope.

• Journal of Korean Neurosurgical Society
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• v.59 no.6
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• pp.637-642
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• 2016

Objective : Although many treatment modalities have been introduced for trigeminal neuralgia (TN), the long-term clinical results remain unsatisfactory. It has been particularly challenging to determine an appropriate treatment strategy for patients who have responded poorly to initial therapies. We analyzed the surgical outcomes in TN patients who failed prior treatments. Methods : We performed a retrospective analysis of 37 patients with recurrent or persistent TN symptoms who underwent surgery at our hospital between January 2010 and December 2014. Patients with follow-up data of at least one year were included. The prior treatment modalities of the 37 patients included microvascular decompression (MVD), gamma knife radiosurgery (GKRS), and percutaneous procedures such as radiofrequency rhizotomy (RFR), balloon compression, and glycerol rhizotomy (GR). The mean follow-up period was 69.9 months (range : 16-173). The mean interval between the prior treatment and second surgery was 26 months (range : 7-123). We evaluated the surgical outcomes using the Barrow Neurological Institute (BNI) pain intensity scale. Results : Among the 37 recurrent or persistent TN patients, 22 underwent MVD with partial sensory rhizotomy (PSR), 8 received MVD alone, and 7 had PSR alone. Monitoring of the surgical treatment outcomes via the BNI pain intensity scale revealed 8 (21.6%) patients with a score of I, 13 (35.1%) scoring II, 13 (35.1%) scoring III, and 3 (8.2%) scoring IV at the end of the follow-up period. Overall, 91.8% of patients had good surgical outcomes. With regard to postoperative complications, 1 patient had transient cerebrospinal fluid rhinorrhea (2.7%), another had a subdural hematoma (2.7%), and facial sensory changes were noted in 8 (21.1%) patients after surgery. Conclusion : Surgical interventions, such as MVD and PSR, are safe and very effective treatment modalities in TN patients who failed initial or prior treatments. We presume that the combination of MVD with PSR enabled us to obtain good short- and long-term surgical outcomes. Therefore, aggressive surgical treatment should be considered in patients with recurrent TN despite failure of various treatment modalities.

• Journal of the Korean Society of Radiology
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• v.11 no.4
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• pp.235-240
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• 2017

The purpose of this study is to confirm the safety of the clinical application of image co - registration in steteotactic radiosurgery by evaluating the 3D positioning of magnetic resonance imaging using image co-registration. We performed a retrospective study using three-dimensional coordinate measurement of 32 patients who underwent stereotactic radiosurgery and performed magnetic resonance imaging follow-up using image co-registration. The 3 dimensional coordinate errors were $1.0443{\pm}0.5724mm$ (0.10 ~ 1.89) in anterior commissure and $1.0348{\pm}0.5473mm$ (0.36 ~ 2.24) in posterior commissure. The mean error of MR1 (3.0 T) was lower than that of MR2 (1.5 T). It is necessary to minimize the error of magnetic resonance imaging in the treatment planning using the image co - registration technique and to confirm it.

• Journal of the Korean Society of Radiology
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• v.14 no.5
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• pp.577-584
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• 2020

In this study, the number of non-English speaking visitors is increasing day by day, and accordingly, there was a limitation in language communication and communication during radiographic examination. To this end, after distributing the handbook produced for inspection, the improvement effect of before and after explanation was examined. The score scale was not statistically significant as to whether it was the test site or not, and the degree of discomfort of the test, the degree of understanding of the breathing guidelines, and the satisfaction of the test description were improved and the score scale was improved before and after the description of the guide. Non-English-speaking foreign visitors were more satisfied with explanations in their own text than in English or Korean, and the method was also able to conduct effective inspections by informing the foreign guests when to control their breathing by using the lighting signals in the laboratory. In the future, the quality of medical services and imaging medical examinations can be improved only when communication methods are implemented from various perspectives, such as developing various language interpretation programs, developing guides for various test sites, and developing tools and improving foreign language skills of radiologists and medical staff. There will be. In the future, it may be used as a basic resource to prepare a manual that can be used to examine non-English speaking foreigners who do not understand English or Korean in other radiology labs.

• Journal of Korean Neurosurgical Society
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• v.66 no.6
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• pp.672-680
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• 2023

Objective : We evaluated the diagnosis, treatment, and long-term results of patients with dural arteriovenous fistula (dAVF), which is a very rare cause of posterior fossa hemorrhage. Methods : This study included 15 patients who underwent endovascular, surgical, combined, or Gamma Knife treatments between 2012 and 2020. Demographics and clinical features, angiographic features, treatment modalities, and outcomes were analyzed. Results : The mean age of the patients was 40±17 years (range, 17-68), and 68% were men (11/15). Seven of the patients (46.6%) were in the age group of 50 years and older. While the mean Glasgow coma scale was 11.5±3.9 (range, 4-15), 46.3% presented with headache and 53.7% had stupor/coma. Four patients (26.6%) had only cerebellar hematoma and headache. All dAVFs had cortical venous drainage. In 11 patients (73.3%), the fistula was located in the tentorium and was the most common localization. Three patients (20%) had transverse and sigmoid sinus localizations, while one patient (6.7%) had dAVF located in the foramen magnum. Eighteen sessions were performed on the patients during endovascular treatment. Sixteen sessions (88.8%) were performed with the transarterial (TA) route, one session (5.5%) with the transvenous (TV) route, and one session (5.5%) with the TA+TV route. Surgery was performed in two patients (14.2%). One patient (7.1%) passed away. While there were nine patients (64.2%) with a Rankin score between 0 and 2, the total closure rate was 69.2% in the first year of control angiograms. Conclusion : In the differential diagnosis of posterior fossa hemorrhages, the differential diagnosis of dAVFs, which is a very rare entity, should be considered, even in the middle and elderly age groups, in patients presenting with good clinical status and pure hematoma. The treatment of such patients can be done safely and effectively in a multidisciplinary manner with a good understanding of pathological vascular anatomy and appropriate endovascular treatment approaches.

• Proceedings of the KOSOMBE Conference
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• v.1992 no.05
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• pp.27-47
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• 1992

Engineers have developed new instruments that aid in diagnosis and therapy Ultrasonic imaging has provided a nondamaging method of imaging internal organs. A complex transducer emits ultrasonic waves at many angles and reconstructs a map of internal anatomy and also velocities of blood in vessels. Fast computed tomography permits reconstruction of the 3-dimensional anatomy and perfusion of the heart at 20-Hz rates. Positron emission tomography uses certain isotopes that produce positrons that react with electrons to simultaneously emit two gamma rays in opposite directions. It locates the region of origin by using a ring of discrete scintillation detectors, each in electronic coincidence with an opposing detector. In magnetic resonance imaging, the patient is placed in a very strong magnetic field. The precessing of the hydrogen atoms is perturbed by an interrogating field to yield two-dimensional images of soft tissue having exceptional clarity. As an alternative to radiology image processing, film archiving, and retrieval, picture archiving and communication systems (PACS) are being implemented. Images from computed radiography, magnetic resonance imaging (MRI), nuclear medicine, and ultrasound are digitized, transmitted, and stored in computers for retrieval at distributed work stations. In electrical impedance tomography, electrodes are placed around the thorax. 50-kHz current is injected between two electrodes and voltages are measured on all other electrodes. A computer processes the data to yield an image of the resistivity of a 2-dimensional slice of the thorax. During fetal monitoring, a corkscrew electrode is screwed into the fetal scalp to measure the fetal electrocardiogram. Correlations with uterine contractions yield information on the status of the fetus during delivery To measure cardiac output by thermodilution, cold saline is injected into the right atrium. A thermistor in the right pulmonary artery yields temperature measurements, from which we can calculate cardiac output. In impedance cardiography, we measure the changes in electrical impedance as the heart ejects blood into the arteries. Motion artifacts are large, so signal averaging is useful during monitoring. An intraarterial blood gas monitoring system permits monitoring in real time. Light is sent down optical fibers inserted into the radial artery, where it is absorbed by dyes, which reemit the light at a different wavelength. The emitted light travels up optical fibers where an external instrument determines O2, CO2, and pH. Therapeutic devices include the electrosurgical unit. A high-frequency electric arc is drawn between the knife and the tissue. The arc cuts and the heat coagulates, thus preventing blood loss. Hyperthermia has demonstrated antitumor effects in patients in whom all conventional modes of therapy have failed. Methods of raising tumor temperature include focused ultrasound, radio-frequency power through needles, or microwaves. When the heart stops pumping, we use the defibrillator to restore normal pumping. A brief, high-current pulse through the heart synchronizes all cardiac fibers to restore normal rhythm. When the cardiac rhythm is too slow, we implant the cardiac pacemaker. An electrode within the heart stimulates the cardiac muscle to contract at the normal rate. When the cardiac valves are narrowed or leak, we implant an artificial valve. Silicone rubber and Teflon are used for biocompatibility. Artificial hearts powered by pneumatic hoses have been implanted in humans. However, the quality of life gradually degrades, and death ensues. When kidney stones develop, lithotripsy is used. A spark creates a pressure wave, which is focused on the stone and fragments it. The pieces pass out normally. When kidneys fail, the blood is cleansed during hemodialysis. Urea passes through a porous membrane to a dialysate bath to lower its concentration in the blood. The blind are able to read by scanning the Optacon with their fingertips. A camera scans letters and converts them to an array of vibrating pins. The deaf are able to hear using a cochlear implant. A microphone detects sound and divides it into frequency bands. 22 electrodes within the cochlea stimulate the acoustic the acoustic nerve to provide sound patterns. For those who have lost muscle function in the limbs, researchers are implanting electrodes to stimulate the muscle. Sensors in the legs and arms feed back signals to a computer that coordinates the stimulators to provide limb motion. For those with high spinal cord injury, a puff and sip switch can control a computer and permit the disabled person operate the computer and communicate with the outside world.

• Radiation Oncology Journal
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• v.15 no.3
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• pp.207-213
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• 1997

Purpose : Intracranial germinoma is the most radiocurable tumor of theprimary intracranial neoplasm. But, the optimum radiation dose and target volume remain controversial In this retrospective study, we analysed the spreading pattern at presentation and the pattern of the failure and survival of intracranial germinoma, Materials and Methods : From 1989 to 1996, 23 Patients were treated for intracranial germinoma at Department of Radiation Oncology, Twenty-one Patients were treated at their initial Presentation and 2 Patients were treated for recurrent disease. Six patients had multiple tumor masses on MRI and 7patients had ventricular seeding on MRI. The examination of cerebrospinal fluid cytology was done in 15 patients and 3 out of 15 patients had positive cerebrospinal cytology. In tumor marker study of $\alpha-FP\;and\;\beta-hCG$, 6 patients had mildly elevated $\beta-hCG$ in serum or cerebrospinal fluid. Twentyone Patients were treated with whole craniospinal axis irradiation and 2 Patients were given whole ventricular radiation therapy. The total dose was ranged between 4500cGy and 5600cGy to primary tumor site (median 5580cGy) Dose to the entire ventricular system ranged from 1980cGy to 3960 cGy (median 2700cGy) and dose to the spinal axis ranged from 2160cGy to 3900cGy (median 2700cGy) Results : Of 23 patients, 21 Patients are alive without evidence of diseasefor median 4 years follow-up. One Patient who had markedly elevated $\alpha-FP\;and\;\beta-hCG$, suffered from Persistent disease after radiation therapy and received 2 cycles of chemotherapy. She died 9 months after chemotherapy One patient who developed ventricular seeding after gamma-knife was treated with whole craniospinal irradiation, he died after 1 year due to probably brain necrosis. The hematologic toxicity of 3 or 4 grade were seen in 7 patients and patient's endocrinologic dysfunction was not deteriorated after radiation therapy. One patient had been treated with growth hormone replacement due to short stature. Conclusions : This retrospective study has confirmed the excellent result of radiation therapy in intracranial germinoma. The complication rate during or after radiation therapy is considered within acceptable range. ft is necessary to further investigate the optimal dose and treatment volume of radiation therapy. The role of chemotherapy in the treatment of intracranial germinoma should be further investigated.

• Radiation Oncology Journal
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• v.27 no.3
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• pp.163-168
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• 2009

Purpose: This study was a retrospective evaluation of the efficacy of stereotactic radiosurgery (SRS) in patients with >4 metastases to the brain. Materials and Methods: Between January 2004 and December 2006, 68 patients with $\geq$4 multiple brain metastases were included and reviewed retrospectively. Twenty-nine patients received SRS and 39 patients received whole brain radiotherapy (WBRT). Patients with small cell lung cancers and melanomas were excluded. The primary lesions were non-small cell lung cancer (69.0%) and breast cancer (13.8%) in the SRS group and non-small cell lung cancer (64.1%), breast cancer (15.4%), colorectal cancer (12.8%), esophageal cancer (5.1%) in the WBRT group. SRS involved gamma-knife radiosurgery and delivered 10~20 Gy (median, 16 Gy) in a single fraction with a 50% marginal dose. WBRT was delivered daily in 3 Gy fractions, for a total of 30 Gy. After completion of treatment, a follow-up brain MRI or a contrast-enhanced brain CT was reviewed. The overall survival and intracranial progression-free survival were compared in each group. Results: The median follow-up period was 5 months (range, 2~19 months) in the SRS group and 6 months (range, 4~23 months) in the WBRT group. The mean number of metastatic lesions in the SRS and WBRT groups was 6 and 5, respectively. The intracranial progression-free survival and overall survival in the SRS group was 5.1 and 5.6 months, respectively, in comparison to 6.1 and 7.2 months, respectively, in the WBRT group. Conclusion: SRS was less effective than WBRT in the treatment of patients with >4 metastases to the brain.