• Journal of the Korean Society of Radiology
• /
• v.85 no.2
• /
• pp.270-296
• /
• 2024

Coronary CT angiography (CCTA) is recognized for its role as a gatekeeper for invasive coronary angiography in patients suspected of coronary artery disease because it can detect significant coronary stenosis with high accuracy. However, heavy plaque in the coronary artery makes it difficult to visualize the lumen, which can lead to errors in the interpretation of the CCTA results. This is primarily due to the limited spatial resolution of CT scanners, resulting in blooming artifacts caused by calcium. However, coronary stenosis with high calcium scores often requires evaluation using CCTA. Technological methods to overcome these limitations include the introduction of high-resolution CT scanners, the development of reconstruction techniques, and the subtraction technique. Methods to improve reading ability, such as the setting of appropriate window width and height, and evaluation of the position of calcified plaque and residual visibility of the lumen in cross-sectional images, are also recommended.

• Journal of Life Science
• /
• v.26 no.9
• /
• pp.1088-1096
• /
• 2016

Despite that moderate hyperthermia can exert various antitumor activities such as direct cytotoxic effects on tumor cells, effects on tumor vasculatures and immunological effects, hyperthermia has been usually combined with radiotherapy or chemotherapy due to its limited efficacy in cancer treatment, showing some positive clinical benefits with generally well-tolerated side effects. Since heat shock responses itself can interfere with the anti-tumor effects of hyperthermia, not all of these studies might have demonstrated positive clinical outcomes in cancer patients. Therefore, the negative anti-tumor effect of hyperthermia should be reduced to enhance the effectiveness of hyperthermia. Although the responses to heat stress of tumor tissues containing vessels, immune cells, connective tissues as well as cancer cells, are very complicated, it is needed to study in the near future if some clinically available drugs, which can modulate heat stress responses, can improve the efficacy of hyperthermia in patients with cancer. In this review, the effect of clinical hyperthermia centered on non-invasive external hyperthermia using radiofrequency at moderate temperature will be discussed, since it is the state-of-the-art technology in the current clinical practice of hyperthermia, and a moderate operational temperature is used to increase the therapeutic effectiveness of conventional therapy without additional toxicity to normal tissues.

• Korean Journal of Clinical Laboratory Science
• /
• v.50 no.4
• /
• pp.477-483
• /
• 2018

Transcranial doppler is a non-invasive method that measures the blood flow velocity and the direction of cerebral blood vessels through the doppler principle. The pulsatility index is an index for measuring the transcranial doppler that reflects the distal vascular resistance and is used as an index for the presence and diffusion of cerebral small vessel diseases. The purpose of this study was to evaluate the risk factors affecting the basilar artery pulsatility index in ischemic stroke patients. From January 2014 to May 2015, 422 patients were selected by measuring the transcranial doppler pulsatility index, considering their basilar artery pulsatility index. Univariate analysis was performed using the basilar artery pulsatility index as a dependent variable. Multiple regression analysis was performed considering the factors affecting the pulsatility index as variables. Univariate analysis revealed age, presence of hypertension, presence of diabetes mellitus, presence of hyperlipidemia, and hematocrit (P<0.1) as factors. Multiple regression analysis showed statistically significant results with age (P<0.001), presence of diabetes (P=0.004), and presence of hyperlipidemia (P=0.041). The risk factors affecting the basilar artery pulsatility index of transcranial doppler were age, diabetes, and hyperlipidemia. Further research will be needed to increase the cerebral pulsatility index as a surrogate marker of the elderly, diabetes, and hyperlipidemia.

• Journal of the Korean Society of Radiology
• /
• v.16 no.3
• /
• pp.309-317
• /
• 2022

It is reported that social distancing caused by the corona pandemic has resulted in a decrease in physical activity, and a decrease in muscle mass due to this increases the risk of vascular disease. Therefore, in this study, the risk of carotid intima media thickness was evaluated by measuring the thickness of CIMT, and the differences in variables according to gender were analyzed. From January 2022 to May 2022, a total of 220 people (121 males, 99 females) who performed blood tests, carotid ultrasound, and body composition analysis among those who visited the health check-up center of Busan H Hospital were included in this study. Significant differences in risk factors according to gender were analyzed using the chi-square test. The cut-off values of variables that can predict the risk of carotid intima media thickness were calculated, and the accuracy was evaluated by calculating the area under the curve, sensitivity, and specificity. As a result of the difference analysis, the higher the total cholesterol in men and the appendicular skeletal muscle index in women, the higher the risk of carotid intima media thickness. The cut-off value for predicting the risk of carotid intima media thickness was calculated to be greater than 199 mg/dL of total cholesterol in the male group and less than 5.9 kg/m² of the appendicular skeletal muscle index in the female group. As a result of this study, the higher the total cholesterol in men and the lower the appendicular skeletal muscle index in women, the higher the risk of increased CIMT. Therefore, in women, the appendicular skeletal muscle index is expected to serve as an indicator to predict and prevent vascular changes at an early stage.

• Journal of the Korean Society of Radiology
• /
• v.17 no.5
• /
• pp.693-699
• /
• 2023

Ultrasound is widely used in the medical field for non-destructive and non-invasive disease diagnosis. In order to improve the disease diagnosis accuracy of diagnostic medical images, improving spatial resolution is a very important factor. In this study, we aim to model the super resolution convolutional neural network (SRCNN) algorithm in ultrasound images and analyze its applicability in the medical diagnostic field. The study was conducted as an experimental study using Field II simulation and open source clinical liver hemangioma ultrasound imaging. The proposed SRCNN algorithm was modeled so that end-to-end learning can be applied from low resolution (LR) to high resolution. As a result of the simulation, we confirmed that the full width at half maximum in the phantom image using a Field II program was improved by 41.01% compared to LR when SRCNN was used. In addition, the peak to signal to noise ratio (PSNR) and structural similarity index (SSIM) evaluation results showed that SRCNN had the excellent value in both simulated and real liver hemangioma ultrasound images. In conclusion, the applicability of SRCNN to ultrasound images has been proven, and we expected that proposed algorithm can be used in various diagnostic medical fields.

• Radiation Oncology Journal
• /
• v.6 no.2
• /
• pp.269-276
• /
• 1988

Eight patients with intracranial tumors or arteriovenous malformation (AVM)s which were less than 3 cm in diameter were treated by a technique of stereotactic radiotherapy during the 4months period from July 1988 through October 1988 at the Division of Radiation Therapy, Kang-Nam St. Mary's Hospital, Catholic University Medical College. The patients were diagnosed as AVMs in 3 cases, acoustic neurinoma, craniopharyngiom (recurrent), hemangioblastoma, pineocytoma, and pituitary microadenoma in each case. There are several important factors in this procedure, such as localization system, portal, field size, radiation dose, and perioperative supportive care. It is suggested that stereotactic radiotherapy may be peformed safely with a radiation dose of 12-30 Gy. So this nonivasive procedure can be used to treat unresectable intracranial tumors or AVMs. Of these, clinical symptoms had been regressed in AVMs in 2 cases at 3 months and 2 months after Stereotactic radiotherapy, one of whom was confirmed slightly regressed on the follow-up angiogram. And also craniopharyngioma and pineocytoma was minimally regressed on 3 month follow-up CT.

• Journal of Chest Surgery
• /
• v.42 no.1
• /
• pp.72-78
• /
• 2009

Background: Mediastinal neurogenic tumors are generally benign lesions and they are ideal candidates for performing resection via video-assisted thoracoscopic surgery (VATS). However, benign neurogenic tumors at the thoracic apex present technical problems for the surgeon because of the limited exposure of the neurovascular structures, and the optimal way to surgically access these tumors is still a matter of debate. This study aims to clarify the feasibility and safety of the VATS approach for performing surgical resection of benign apical neurogenic tumors (ANT). Material and Method: From January 1996 to September 2008, 31 patients with benign ANT (15 males/16 females, mean age: 45 years, range: 8~73), were operated on by various surgical methods: 14 VATS, 10 lateral thoracotomies, 6 cervical or cervicothoracic incisions and 1 median sternotomy. 3 patients had associated von Recklinhausen's disease. The perioperative variables and complications were retrospectively reviewed according to the surgical approaches, and the surgical results of VATS were compared with those of the other invasive surgeries. Result: In the VATS group, the histologic diagnosis was schwannoma in 9 cases, neurofibroma in 4 cases and ganglioneuroma in 1 case, and the median tumor size was 4.3 cm (range: 1.2~7.0 cm). The operation time, amount of chest tube drainage and the postoperative stay in the VATS group were significantly less than that in the other invasive surgical group (p<0.05). No conversion thoracotomy was required. There were 2 cases of Hornor's syndrome and 2 brachial plexus neuropathies in the VATS group; there was 1 case of Honor's syndrome, 1 brachial plexus neuropathy, 1 vocal cord palsy and 2 non-neurologic complications in the invasive surgical group, and all the complications developed postoperatively. The operative method was an independent predictor for postoperative neuropathies in the VATS group (that is, non-enucleation of the tumor) (p=0.029). Conclusion: The VATS approach for treating benign ANT is a less invasive, safe and feasible method. Enucleation of the tumor during the VATS procedure may be an important technique to decrease the postoperative neurological complications.

• Journal of Chest Surgery
• /
• v.37 no.12
• /
• pp.992-998
• /
• 2004

Background: The decision of staging of esophageal cancer have great effect on the resectability of the lesion and estimation of the patient's prognosis. Today, CT is one of the most popular modality for staging of esophageal cancer. However, it has some limitations because of false-positive or false-negative findings on cancer staging. The purpose of this study was to analyze the efficacy of CT in preoperative staging of esophageal cancer. Material and Method: We retrospectively analysed the difference of staging of esophageal cancer between CT and histopathological findings for the 114 patients with histologically proven esophageal cancer who underwent operation at the department of thoracic and cardiovascular surgery, Chonnam national university hospital, between January 1999 and June 2003. We evaluated the efficacy of chest CT in the staging of esophageal cancer compared to postoperative histopathologic findings by calculating sensitivity, specificity, accuracy, and reproducibility of chest CT to detect abnormality. Result: The reproducibilities between chest CT and histopathologic findings were 0.32 (p<0.01) for primary tumor (T), 0.36 (p<0.01) for lymph node invasion (N), and 0.62 (p<0.01) for distant metastasis (M). The reproducibilities between chest CT and histopathologic findings for lymph node invasion (N) and distant metastasis (M) were superior to that of primary tumor (T). The accuracy of primary tumor (T) was 65.8% and 98.2% in group III and IV, which was significantly higher than that of group I and II (78.9% and 62.3%). In general, specificity of chest CT for TNM staging was superior to sensitivity. Conclusion: In conclusion, preoperative CT scanning can provide important information on lymph node invasion and metastasis of lesion than primary tumor invasion.

• Journal of Chest Surgery
• /
• v.41 no.5
• /
• pp.598-604
• /
• 2008

Background: The improvements in endoscopic equipment and surgical robots has encouraged the performance of minimally invasive cardiac operations. Yet only a few Korean studies have compared this procedure with the sternotomy approach. Material and Method: Between December 2005 and July 2007, 48 patients (group A) underwent minimally invasive cardiac surgery with AESOP through a small right thoracotomy. During the same period, 50 patients (group B) underwent conventional surgery. We compared the operative time, the operative results, the post-operative pain and the recovery of both groups. Result: There was no hospital mortality and there were no significant differences in the incidence of operative complications between the two groups. The operative $(292.7{\pm}61.7\;and\;264.0{\pm}47.9min$, respectively; p=0.01) and CPB times ($128.4{\pm}37.6\;and\;101.7{\pm}32.5min$, respectively; <0.01) were longer for group A, whereas there was no difference between the aortic cross clamp times ($82.1{\pm}35.0\;and\;87.8{\pm}113.5min$, respectively; p=0.74) and ventilator times ($18.0{\pm}18.4\;and\;19.7{\pm}9.7$ hr, respectively; p=0.57) between the groups. The stay on the ICU $(53.2{\pm}40.2\;and\;72.8{\pm}42.1hr$, respectively; p=0.02) and the hospitalization time ($9.7{\pm}7.2\;and\;14.8{\pm}11.9days$, respectively; p=0.01) were shorter for group A. The Patients in group B had more transfusions, but the difference was not significant. For the overall operative intervals, which ranged from one to four weeks, the pair score was significantly lower for the patients of group A than for the patients of group B. In terms of the postoperative activities, which were measured by the Duke Activity Scale questionnaire, the functional status score was clearly higher for group A compared to group B. The analysis showed no difference in the severity of either post-repair of mitral ($0.7{\pm}1.0\;and\;0.9{\pm}0.9$, respectively; p=0.60) and tricuspid regurgitation ($1.0{\pm}0.9\;and\;1.1{\pm}1.0$, respectively; p=0.89). In both groups, there were no valve related complications, except for one patient with paravalvular leakage in each group. Conclusion: These results show that compared with the median sternotomy patients, the patients who underwent minimally invasive surgery enjoyed significant postoperative advantages such as less pain, a more rapid return to full activity, improved cosmetics and a reduced hospital stay. The minimally invasive surgery can be done with similar clinical safety compared to the conventional surgery that's done through a median sternotomy.

• Clinical and Experimental Pediatrics
• /
• v.48 no.12
• /
• pp.1362-1369
• /
• 2005

Purpose : This study aimed to investigate the correlation between the plasma level of N-terminal pro-B-type natriuretic peptide(pro-BNP) and several known risk factors influencing outcomes after Fontan operations, and to assess whether pro-BNP levels can be used as predictive risk factors in Fontan operations. Methods : Plasma pro-BNP concentrations were measured in 35 patients with complex cardiac anomalies before catheterization. Cardiac catheterization was performed in all subjects. Mean right atrium pressure, mean pulmonary artery pressure(PAP), and ventricular end-diastolic pressure(EDP) were obtained. Cardiac output and pulmonary vascular resistance were calculated by Fick method. Results : Plasma pro-BNP levels exhibited statistically significant positive correlations with mean PAP(r=0.70, P<0.001), pulmonary vascular resistance(r=0.57, P<0.001), RVEDP(r=0.63, P<0.001), LVEDP(r=0.74, P<0.001), and cardiothoracic ratio(r=0.71, P<0.001). The area under the ROC curve using pro-BNP level to differentiate risk groups in Fontan operations was high : 0.868(95 percent CI, 0.712-1.023, P<0.01). The cutoff value of pro-BNP concentrations for the detection of risk groups in Fontan operations was determined to be 332.4 pg/mL(sensitivity 83.3 percent, specificity 82.7 percent). Conclusion : These data suggest that plasma pro-BNP levels may be used as a predictive risk factor in Fontan operations, and as a guide to determine the mode of therapy during follow-up after Fontan operations.