• Journal of Chest Surgery
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• v.42 no.2
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• pp.252-255
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• 2009

We performed a hybrid procedure for a 58-year-old man with coronary artery disease and a left subclavian artery stenosis. He underwent left subclavian artery stenting and off-pump coronary artery bypass surgery, including grafting the in situ left internal mammary artery to the left anterior descending coronary artery. The post-operative coronary angiogram and computed tomography showed good patency of the graft and stent. He discharged at postoperative 8 days and he has been followed up for six month with an excellent clinical condition.

• Journal of Chest Surgery
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• v.54 no.6
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• pp.513-516
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• 2021

An 87-year-old man presented with a saccular aneurysm at the proximal descending thoracic aorta. As computed tomography revealed a shaggy aorta, we planned hybrid thoracic endovascular aortic repair (TEVAR) with embolic protection devices (EPDs) in both internal carotid arteries to prevent a cerebrovascular accident. We inserted an Emboshield NAV⁶ Embolic Protection System (Abbott Vascular, Abbott Park, IL, USA) into both internal carotid arteries before performing the TEVAR procedure. The patient was discharged from the hospital on postoperative day 4 without any neurological complications.

• Journal of Chest Surgery
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• v.43 no.4
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• pp.458-461
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• 2010

A 53-year-old woman had right aortic arch, Kommerell’s diverticulum and aberrant left subclavian artery (LSA) without any compressive symptoms. Hybrid operation was performed. This consisted of LSA bypass using a 6 mm ringed Gore-Tex graft between the left common carotid artery and aberrant LSA via a left supraclavicular incision, and stent graft insertion into the aortic arch via the right femoral artery. Postoperative computed tomography as well as intraoperative angiography demonstrated successful occlusion of Kommerell’s diverticulum and bypass of the aberrant LSA. There were no complications related to the operation or the intervention.

• Journal of Trauma and Injury
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• v.34 no.3
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• pp.191-197
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• 2021

Renal injuries occur in more than 10% of patients who sustain blunt abdominal injuries. Non-operative management (NOM) is the established treatment strategy for lowgrade (I-III) renal injuries. However, despite some evidence that NOM can be successfully applied to high-grade (IV, V) renal injuries, it remains unclear whether NOM is appropriate in such cases. The authors report two cases of high-grade renal injuries that underwent NOM after embolization in a hybrid emergency room (ER) system with a 24/7 in-house interventional radiology (IR) team. A 29-year-old male visited Wonkwang University Hospital Regional Trauma Center complaining of right abdominal pain after being hit by a rope. Computed tomography (CT) was performed 16 minutes after arrival, and the CT scan indicated a grade V right renal injury. Arterial embolization was initiated within 31 minutes of presentation. A 56-year-old male was transferred to Wonkwang University Hospital Regional Trauma Center with a complaint of right flank pain. He had initially presented to a nearby hospital after falling from a 3-m height. Thanks to the key CT images sent from the previous hospital prior to the patient's arrival, angiography was performed within 8 minutes of the patient's arrival and arterial embolization was completed within 25 minutes. Both patients were treated successfully through NOM with angioembolization and preserved kidneys. Hematoma in the first patient and urinoma in the second patient resolved with percutaneous catheter drainage. The authors believe that the hybrid ER system with an in-house IR team could contribute to NOM and kidney preservation even in high-grade renal injuries.

• Composites Research
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• v.31 no.6
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• pp.317-322
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• 2018

In various industry, the composite is tried to be applied to products and thermoplastic based composite is in the spotlight because this composite can be recycled. The use of continuous fiber thermoplastic (CFT) method increased gradually than long fiber thermoplastic (LFT). In this study, tensile, flexural, and impact test of different array types of glass fiber (GF)/thermoplastic composites were performed to compare with GF array. Impregnation property between GF mat and thermoplastic was determined using computed tomography (CT). At CFT method, thermoplastic film is not wet into GF roving and many voids are appeared into composite. This phenomenon affects to decrease mechanical properties. Plain pattern GF mat was the best mechanical and impregnation properties that distance between two roving was set closely to $100{\mu}m$.

• Korean Journal of Radiology
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• v.23 no.11
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• pp.1044-1054
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• 2022

Objective: This study aimed to investigate whether a deep learning reconstruction (DLR) method improves the image quality, stent evaluation, and visibility of the valve apparatus in coronary computed tomography angiography (CCTA) when compared with filtered back projection (FBP) and hybrid iterative reconstruction (IR) methods. Materials and Methods: CCTA images of 51 patients (mean age ± standard deviation [SD], 63.9 ± 9.8 years, 36 male) who underwent examination at a single institution were reconstructed using DLR, FBP, and hybrid IR methods and reviewed. CT attenuation, image noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and stent evaluation, including 10%-90% edge rise slope (ERS) and 10%-90% edge rise distance (ERD), were measured. Quantitative data are summarized as the mean ± SD. The subjective visual scores (1 for worst -5 for best) of the images were obtained for the following: overall image quality, image noise, and appearance of stent, vessel, and aortic and tricuspid valve apparatus (annulus, leaflets, papillary muscles, and chordae tendineae). These parameters were compared between the DLR, FBP, and hybrid IR methods. Results: DLR provided higher Hounsfield unit (HU) values in the aorta and similar attenuation in the fat and muscle compared with FBP and hybrid IR. The image noise in HU was significantly lower in DLR (12.6 ± 2.2) than in hybrid IR (24.2 ± 3.0) and FBP (54.2 ± 9.5) (p < 0.001). The SNR and CNR were significantly higher in the DLR group than in the FBP and hybrid IR groups (p < 0.001). In the coronary stent, the mean value of ERS was significantly higher in DLR (1260.4 ± 242.5 HU/mm) than that of FBP (801.9 ± 170.7 HU/mm) and hybrid IR (641.9 ± 112.0 HU/mm). The mean value of ERD was measured as 0.8 ± 0.1 mm for DLR while it was 1.1 ± 0.2 mm for FBP and 1.1 ± 0.2 mm for hybrid IR. The subjective visual scores were higher in the DLR than in the images reconstructed with FBP and hybrid IR. Conclusion: DLR reconstruction provided better images than FBP and hybrid IR reconstruction.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.15 no.2
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• pp.102-110
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• 2015

The main source of noise in computed tomography (CT) images is a quantum noise, which results from statistical fluctuations of X-ray quanta reaching the detector. This paper proposes a neural network (NN) based hybrid filter for removing quantum noise. The proposed filter consists of bilateral filters (BFs), a single or multiple neural edge enhancer(s) (NEE), and a neural filter (NF) to combine them. The BFs take into account the difference in value from the neighbors, to preserve edges while smoothing. The NEE is used to clearly enhance the desired edges from noisy images. The NF acts like a fusion operator, and attempts to construct an enhanced output image. Several measurements are used to evaluate the image quality, like the root mean square error (RMSE), the improvement in signal to noise ratio (ISNR), the standard deviation ratio (MSR), and the contrast to noise ratio (CNR). Also, the modulation transfer function (MTF) is used as a means of determining how well the edge structure is preserved. In terms of all those measurements and means, the proposed filter shows better performance than the guided filter, and the nonlocal means (NLM) filter. In addition, there is no severe restriction to select the number of inputs for the fusion operator differently from the neuro-fuzzy system. Therefore, without concerning too much about the filter selection for fusion, one could apply the proposed hybrid filter to various images with different modalities, once the corresponding noise characteristics are explored.

• Progress in Medical Physics
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• v.32 no.2
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• pp.40-49
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• 2021

Purpose: This study aimed to develop a surface-guided radiosurgery system customized for a neurosurgery clinic that could be used as an auxiliary system for improving the accuracy, monitoring the movements of patients while performing hypofractionated radiosurgery, and minimizing the geometric misses. Methods: RGB-D cameras were installed in the treatment room and a monitoring system was constructed to perform a three-dimensional (3D) scan of the body surface of the patient and to express it as a point cloud. This could be used to confirm the exact position of the body of the patient and monitor their movements during radiosurgery. The image from the system was matched with the computed tomography (CT) image, and the positional accuracy was compared and analyzed in relation to the existing system to evaluate the accuracy of the setup. Results: The user interface was configured to register the patient and display the setup image to position the setup location by matching the 3D points on the body of the patient with the CT image. The error rate for the position difference was within 1-mm distance (min, -0.21 mm; max, 0.63 mm). Compared with the existing system, the differences were found to be as follows: x=0.08 mm, y=0.13 mm, and z=0.26 mm. Conclusions: We developed a surface-guided repositioning and monitoring system that can be customized and applied in a radiation surgery environment with an existing linear accelerator. It was confirmed that this system could be easily applied for accurate patient repositioning and inter-treatment motion monitoring.

• Journal of Trauma and Injury
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• v.36 no.4
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• pp.435-440
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• 2023

Mesenteric injury occurs rarely in cases associated with blunt abdominal trauma. Despite its low incidence, mesenteric injury can lead to fatal outcomes such as hypovolemic shock due to hemoperitoneum or sepsis due to intestinal ischemia, or perforation-related peritonitis. For mesenteric injuries, especially those involving massive bleeding, intestinal ischemia, and perforation, the standard treatment is surgery. However, in the case of operative management, it should be borne in mind that there is a possibility of complications and mortality during and after surgery. The usefulness of transcatheter arterial embolization (TAE) is well known in solid organs but is controversial for mesenteric injury. We present a 75-year-old man with mesenteric injury due to blunt abdominal trauma. Initial abdominal computed tomography showed no hemoperitoneum, but a mesenteric contusion and pseudoaneurysm with a diameter of 17 mm were observed near the origin of the superior mesenteric artery. Since there were no findings requiring emergency surgery such as free air or intestinal ischemia, it was decided to perform nonoperative management with TAE using microcoils in hybrid emergency room system. TAE was performed successfully, and there were no complications such as bleeding, bowel ischemia, or delayed bowel perforation. He was discharged on the 23rd day after admission with percutaneous catheter drainage for drainage of mesenteric hematoma. The authors believe that treatment with TAE for highly selected elderly patients with mesenteric injuries has the positive aspect of minimally invasive management, considering the burden of general anesthesia and the various avoidable intraoperative and postoperative complications.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.2
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• pp.98-111
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• 2008

This review introduces advances in clinical and pre-clinical single photon emission computed tomography (SPECT) and positron emission tomography (PET) providing noninvasive functional images of biological processes. Development of new collimation techniques such as multi-pinhole and slit-slat collimators permits the improvement of system spatial resolution and sensitivity of SPECT. Application specific SPECT systems using smaller and compact solid-state detector have been customized for myocardial perfusion imaging with higher performance. Combined SPECT/CT providing improved diagnostic and functional capabilities has been introduced. Advances in PET and CT instrumentation have been incorporated in the PET/CT design that provide the metabolic information from PET superimposed on the anatomic information from CT. Improvements in the sensitivity of PET have achieved by the fully 3D acquisition with no septa and the extension of axial field-of-view. With the development of faster scintillation crystals and electronics, time-of-flight (TOF) PET is now commercially available allowing the increase in the signal-to-noise ratio by incorporation of TOF information into the PET reconstruction process. Hybrid PET/SPECT/CT systems has become commercially available for molecular imaging in small animal models. The pre-clinical systems have improved spatial resolution using depth-of-interaction measurement and new collimators. The recent works on solid state detector and dual modality nuclear medicine instrumentations incorporating MRI and optical imagers will also be discussed.