• Journal of radiological science and technology
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• v.43 no.2
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• pp.79-85
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• 2020

The influence of metal artifact in CT image depends on the type of metal materialsm, the reconstruction algorithm, and scan parameters. The presence of metal artifacts was quantitatively evaluated by applying the standard and MAR algorithms through the phantom study. In the change of tube voltage applied the standard algorithm, metal artifact decreased to 44.9% for 80 vs 120 kVp, 24% for 100 vs 120 kVp, while the image taken at 140 kVp increased the artifact by 19% compared to 120 kVp. When the tube current was increased from 100 to 300 mA, there was no significant difference in the CT value and noise. Black band and white strike artifacts occurred up to 65.9% in the adjacent ROI of the metal driver, whereas titanium screw produced lesser metal artifact than that of the metal driver. The combination of 120kVp or higher tube voltage-standard algorithm was effective in removing black band artifacts as well as white streak by high density materials. However, MAR reconstruction algorithm was useful in improving image quality under the environment of low kVp and high density materials, without increase of radiation exposure.

• The Journal of Advanced Prosthodontics
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• v.14 no.6
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• pp.369-378
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• 2022

PURPOSE. The purpose of this in vitro study was to assess whether scanning strategies of virtual interocclusal record (VIR) affect the accuracy of VIR during intraoral scanning. MATERIALS AND METHODS. Five pairs of reference cubes were added to the digital upper and lower dentitions of a volunteer, which were printed into resin casts. Subsequently, the resin casts were articulated in the maximal intercuspal position in a mechanical articulator and scanned with an industrial computed tomography system, of which the VIR was served as a reference VIR. The investigated VIR of the upper and lower jaws of the resin master cast were recorded with an intraoral scanner according to 9 designed scanning strategies. Then, the deviation between the investigated VIRs and reference VIR were analyzed, which were measured by the deviation of the distances of six selected reference points on the upper reference cubes in each digital cast to the XY-plane between the investigated VIRs and reference VIR. RESULTS. For the deviation in the right posterior dentitions, RP group (only scanning of right posterior dentitions) showed the smallest deviation. Besides, BP group (scanning of bilateral posterior dentitions) showed the smallest deviation in the left posterior dentitions. Moreover, LP group (scanning of left posterior dentitions) showed the smallest deviation in the anterior dentitions. For the deviation of full dental arches, BP group showed the smallest deviation. CONCLUSION. Different scanning strategies of VIR can influence the accuracy of alignment of virtual dental casts. Appropriate scanning strategies of VIR should be selected for different regions of interest and edentulous situations.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.8
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• pp.417-421
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• 2018

Carboxytherapy is very similar to mesotherapy in terms of methods, conditions it treats, and outcomes. An important difference consider, however, is that carboxytherapy administers carbon dioxide gas into the subcutaneous layer, just underneath the skin, whereas mesotherapy administers a cocktail of vitamins, minerals, and drugs and into the mesoderm of the skin. There have been many previous case reports of complications of mesotherapy such as hematoma, granulomatous panniculitis, cellulitis, and abscesses. However, complications of carboxytherapy have rarely been reported because the carbon dioxide gas is absorbed within a week and is infused into the subcutaneous and superficial layers. A 27-year-old woman who had twice undergone carboxytherapy to reduce abdominal fat (3 days and 2 weeks ago) at an oriental medical clinic visited the emergency department due to high fever, myalgia, severe back pain, and subcutaneous emphysema from the buttocks to the lower chest wall area. A computed tomography (CT) scan was performed for diagnosis and treatment. We immediately started broad spectrum antibiotics and consulted with the department of radiology, which could not rule out acute peritonitis due to needle injury. A radiologist confirmed abdominal myositis and needle puncture induced acute pyelonephritis. Pyelonephritis can even lead to septicemia, which can have fatal consequences. Therefore, if the patient has costovertebral or back pain after undergoing needle puncture or acupuncture therapy, the emergency physcians need careful initial evaluation for diagnosis and treatment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.8
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• pp.84-87
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• 2017

Cerebral hyperperfusion syndrome (CHS) is a rare complication that can occur when conducting stent insertion or endarterectomy in patients with carotid artery stenosis and is known to be caused by various mechanisms when the blood volume abruptly increases. The main clinical symptoms are unilateral headache, hypertension, seizure, and focal neurologic deficit. Subarachnoid hemorrhage and parenchymal hemorrhage may lead to permanent impairment or death in severe cases. CHS can be predicted by using transcranial Doppler, perfusion magnetic resonance imaging, and single photon emission computed tomography. In our case report, a patient developed CHS subsequent to significant venous congestion caused by carotid artery stent insertion. The patient had preexisting, symptomatic bilateral carotid artery stenosis. Venous congestion occurs when the direction of blood flow changes because of increased blood volume in patients with well-developed collateral vessels. We believe that CHS can be predicted from this finding. This study reports the possibility that CHS could be confirmed by cerebral angiography after insertion of the internal carotid stent.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.7
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• pp.84-91
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• 2017

This study was performed using Somatom Definition Flash (Siemens, Enlarge, Germany) and GE 64-MDCT (Discovery 750 HD, GE HEALTHCARE, Milwaukee, USA.) using high-density medical materials that (are indispensable to?) computed tomography. We analyzed quantitatively the rate of change of the CT number of the CT reconstruction images by means of the IMAR and MAR algorithms using the phantom images acquired after scanning and previously captured raw data images. As a result, it was shown that the IMAR and MAR algorithms provided if ferent phantom images in the case of all medical high-density materials (p <0.05). The black streak artifacts were analyzed using the MAR and IMAR algorithms to determine if they corresponded to stainless steel materials (p>0.05). Also, it was found that the application of the IMAR algorithm affects the attenuation deviation, because there is a change in the image CT number compared to that before. The results suggest that, in the future, after the implant procedure, it would be useful to observe the surgical site and surrounding tissues during follow-up CT scans.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.6
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• pp.427-431
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• 2018

We report a case of a patient with necrotizing fasciitis followed by liver abscess. A 51-year-old man was admitted to our hospital with a 5-day history of fever and chills with painful swelling of the right thigh. A magnetic resonance imaging (MRI) scan showed fluid collection with numerous dark signal intensities considered as air-bubbles between the posteromedial and posterolateral groups of the right thigh, resulting in presumptive diagnosis of necrotizing fasciitis. At the time of admission, an ultrasonograph of the abdomen showed increased parenchymal echogenicity of both kidneys and no liver abscess. Ten days after fasciotomy, an abdominal computed tomography (CT) scan showed intrahepatic abscess. Sonography-guided percutaneous drainage was performed. Both cultures of pus specimens from the liver abscess and right thigh yielded Klebsiella pneumoniae (K. pneumoniae). The patient was treated with fasciotomy several times and parenteral antibiotics, after which he began to improve. After 5 weeks, liver abscess size was reduced, and after 10 weeks, liver abscess disappeared. To the best of our knowledge, this is the first case of K. pneumoniae-necrotizing fasciitis followed by liver abscess.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.208-212
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• 2017

A urinary calculus in the urethra is rarely seen and usually encountered in men with a urethral stricture or diverticulum. Herein, we report a rare case of a giant calculus in the urethra of a 42-year-old male patient with paraplegia after spinal cord injury due to car accident 20 years ago. A recent urologic consultation from the emergency room was performed since the patient had multidisciplinary symptoms during the day without any urination and presented with urinary difficulties due to hematuria and pain symptoms occurring with a mass in the bottom of the testicles. Abdomen and pelvic computed tomography (CT) was performed to examine the tumor mass, which was found to be absent. In addition, urethral stones were observed in the CT. Cystostomy was performed after the first urethroplasty, and the stone was removed from the urethra. Two weeks later, the patient was subjected to urethrography to remove the Foley catheter. No specific finding in voiding was detected. Giant urethral stones sometime require differentiation from tumor status. Treatment may vary according to size and location, requiring careful examination.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.188-193
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• 2019

Transarterial chemoembolization (TACE) is a commonly used and rapidly evolving non-invasive treatment for hepatocellular carcinoma (HCC). It is important that understanding individual anatomical variants and planning for tumor-feeding artery access to acquire adequate treatment effectiveness. In this study, we will report acquired arteriovenous malformation which interferes with TACE for HCC. A 72-year-old man with persistent abdominal pain for 2 days visited our hospital. The patient was chronic hepatitis B carrier and had a history of HCC treated with conventional TACE 10 years ago. Hypervascular nodular HCC in the liver segment 8 and aberrant right hepatic artery from the superior mesenteric artery were detected on computed tomography (CT). When first TACE was performed, the tumor-feeding artery originating from the left hepatic artery was found and embolized. There was no tumor-feeding artery from the right hepatic artery but arteriovenous malformation was found. After a month, follow up CT showed necrotic lesion and residual HCC and we performed secondary TACE. On secondary TACE, we selected the right hepatic artery and passed through arteriovenous malformation. Superselective-angiogram showed remnant tumoral staining and remnant tumor was embolized using drug-eluting bead and Adriamycin. Final angiogram showed no remnant tumoral staining and the patient was discharged without complication. We found the rare case of arteriovenous malformation adjacent to HCC, and we performed superselective TACE beyond arteriovenous malformation to treat HCC.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.423-428
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• 2019

The role of angioembolization has increased because of increases in nonoperative treatment for traumatic splenic injury. We report here a case of successful treatment of iatrogenic pseudoaneurysm of the femoral artery by thrombin injection with coil embolization. A 55-year-old female was admitted to our hospital because of blunt trauma. Computed tomography (CT) revealed a grade V splenic injury with contrast extravasation; therefore, angioembolization was performed. Three days after admission, follow-up CT scan revealed rebleeding from the spleen, and repeat angioembolization was performed. Seven days after admission, an approximately $7.0cm{\times}4.0cm-sized$ pseudoaneurysm was found on follow-up CT scan and there was no bleeding from the spleen. Although thrombin was injected into the aneurysmal sac, there was still inflow of blood, as observed on color-doppler ultrasound. Therefore, coil embolization to the neck of the aneurysm was performed. On angiography, there was no contrast filling into the sac. The size of the pseudoaneurysmal sac had decreased on follow-up CT scan, and the patient was discharged to home without complications. We successfully treated a giant pseudoaneurysm of the femoral artery using thrombin and coil embolization.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.371-375
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• 2019

The role of resuscitative endovascular balloon occlusion of the aorta (REBOA) in hemodynamically unstable pancreatic trauma is unclear. We report here a case of traumatic pancreatic bleeding controlled with REBOA and angioembolization of the splenic artery before surgery. A 65-year old man experienced blunt trauma upon falling from a height of 20 m. Computed tomography (CT) revealed distal pancreatic trauma (grade III) and contrast extravasation around the splenic artery. Shortly after CT, his systolic blood pressure was 60 mmHg and REBOA was performed for hemodynamic stability. His systolic pressure increased to 130 mmHg after balloon inflation and angioembolization of the splenic artery was performed. On angiography, no further arterial bleeding was identified and the balloon was removed. Subsequently, the patient underwent emergent laparotomy with distal pancreatectomy. There was no active bleeding during surgery and distal main pancreatic duct injury was identified. After surgery, the patient recovered without complication. In this case, hemodynamically unstable hemorrhagic pancreatic trauma was treated effectively and safely with distal pancreatectomy after REBOA with angioembolization.