• Journal of the Korean Society of Radiology
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• v.17 no.1
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• pp.123-129
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• 2023

The purpose of this study was to analyze differences in imaging quality and dose difference between intra-venous (IV) and intra-arterial (IA) liver dynamic computed tomography (CT). Herein, retrospective, blinded analysis was conducted to analyze signal-to-noise and contrast-to-noise ratios in cases of patients who underwent IV or IA liver dynamic CT for transarterial chemoembolization (TACE), an interventional procedure for hepatocellular carcinoma. The dose length product (DLP) value stored in Picture Archive and Communication System (PACS) was used to calculate the effective dose and thereby compare differences in the dose between the two methods. The mean liver and spleen signal to noise ratio (SNR) was greater in IV-liver dynamic CT than in IA-liver dynamic CT; however, contrast to noise ratio (CNR) was higher in IA-liver dynamic CT than in IV-liver dynamic CT. However, there were no differences in DLP and effective dose between the two methods. In conclusion, our findings showed that IA-liver dynamic CT showed a similar effective dose and superior CNR compared with IV-liver dynamic CT. Further studies must analyze 3D angiography CT of the hepatic artery to clearly distinguish the feeding artery, which is the essential step in interventional procedures for hepatocellular carcinoma.

• Journal of Veterinary Clinics
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• v.30 no.2
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• pp.111-114
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• 2013

A 4-year-old spayed female Miniature Pinscher was presented with a 3.5-year history of elevated liver enzymes level. Continuous elevation of liver enzymes was found on repeated blood examinations and the dog was referred for further evaluation. The abdominal ultrasonography revealed that the gallbladder could not be visualized in any plane. The absence of gallbladder was suspected on ultrasonography. Computed tomography (CT) confirmed gallbladder agenesis (GBA). This is the first reported case of diagnosis of GBA in Miniature Pinscher by using CT.

• Journal of the Korean Society of Radiology
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• v.11 no.6
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• pp.453-458
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• 2017

Computed Tomography (CT) provides information on the Diagnostic Reference Level Computed Tomography Dose Index (CTDI) and Dose Length Product (DLP) for accurate diagnosis of patients. However, it does not provide a dose change according to the table height for the diagnostic reference level provided by the CT equipment. The purpose of this study was to evaluate the image and dose according to the table height change using phantom (PMMA: Polymethyl Methacrylate) in order to find the optimal image and the minimum dose during computed tomography examination. When examining using a 32 cm PMMA phantom with the same thickness as the abdomen of an adult, there was little change in dose with table height. However, the noise evaluation of the image caused a high fluctuation of noise depending on the table height. and in the case of the 16 cm PMMA phantom, the change of the noise was small, but the dose change was about 30%. In conclusion, the location of the patient and the center of the detector are important during computed tomography (CT) examinations. In addition, table height setting is considered to be important for examinations with optimized image and minimum dose.

• Journal of the Korean Society of Radiology
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• v.15 no.3
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• pp.293-299
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• 2021

In order to reduce the irresistible radiation exposure of patients who perform periodic examinations using a CT among various scan parameters a method to reduce patient dose was investigated through changes in the tube voltage close to X-ray penetrating power. As a result of the experiment 100 kVp was applied instead of 120 kVp which is commonly used in clinical practice and CTDI decreased by about 41% during scan. In addition the degree of change in image quality was measured as 1046.1±3.7 HU for CT value and 71.4±7.9 for Pixel value and statistical analysis showed no significant difference (0.05

• Progress in Medical Physics
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• v.9 no.1
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• pp.47-53
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• 1998

Nuclear Medicine Images have comparatively poor spatial resolution, making it difficult to relate the functional information which they contain to precise anatomical structures. Anatomical structures useful in the interpretation of SPECT /PET Images were radiolabelled. PET/SPECT Images Provide functional information, whereas MRI mainly demonstrate morphology and anatomical. Fusion or Image Registration improves the information obtained by correlating images from various modalities. Brain Scan were studied on one or more occations using MRI and SPECT. The data were aligned using a point pair methods and surface matching. SPECT and MR Images was tested using a three dimensional water fillable Hoffman Brain Phantom with small marker and PET and MR Image was tested using a patient data. Registration of SPECT and MR Images is feasible and allows more accurate anatomic assessment of sites of abnormal uptake in radiolabeled studies. Point based registration was accurate and easily implemented three dimensional registration of multimodality data set for fusion of clinical anatomic and functional imaging modalities. Accuracy of a surface matching algorithm and homologous feature pair matching for three dimensional image registration of Single Photon Emission Computed Tomography Emission Computed Tomography (SPECT), Positron Emission Tomography (PET) and Magnetic Resonance Images(MRD was tested using a three dimensional water fill able brain phantom and Patients data. Transformation parameter for translation and scaling were determined by homologous feature point pair to match each SPECT and PET scan with MR images.

• Journal of Veterinary Clinics
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• v.29 no.2
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• pp.190-193
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• 2012

A 2-month-old, intact female Alaskan Malamute was presented for evaluation of dyspnea and subcutaneous emphysema of the neck following biting wound. Two small punctured skin lesions and crepitus on the neck were found during physical examination. Radiographs revealed pneumomediastinum and subcutaneous emphysema. Confirmative diagnosis of tracheal laceration was made by identifying the tracheal wall discontinuity on the computed tomography. CT is a valuable tool to diagnose an external traumatic tracheal injury, and more specifically, to assess the location and the extent of laceration, and it leads to early definitive treatment and reduction of the incidence of complications.

• Journal of Chest Surgery
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• v.36 no.1
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• pp.39-42
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• 2003

Endobronchial lipomas are rare benign tumors that arise from the lung. They partially or totally obstruct the bronchial lumen, producing a variable degree of collapse, irreversible bronchiectasis, and pulmonary damage. Although bronchoscope, CT and MR are reported to be helpful in establishing the diagnosis, CT is highly specific and sensitive in detecting fatty tumor. They may be removed by endoscope or thoracotomy or lobectomy. We present a case of endobronchial lipoma completely obstructing the right middle lobe and postobstructive irreversible pulmonary change with review of literatures.

• Journal of Veterinary Clinics
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• v.31 no.5
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• pp.376-381
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• 2014

In this study, we analyzed the computed tomography (CT) measurements of lung volume and density in dogs with relation to body weight, age, sex, and breed. The multi-detector CT examination of the thorax was performed on dogs without respiratory or cardiovascular diseases. Three-dimensional reconstruction of CT images facilitated measurement of lung volume and density. There was a statistical significant correlation between body weight and lung volume (p < 0.0001). Lung density significantly decreased with an increase in body weight (p = 0.0078). However, no correlation was seen between these lung parameters and either sex or age of the dogs. In conclusion, this study shows that body weight is an important factor to consider when interpreting total lung volume and density values measured by quantitative CT. We highlight the need for further study using quantitative CT in identifying the potential effects of sex, age, and disease status on these parameters.

• Journal of the Korean Society of Radiology
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• v.16 no.5
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• pp.619-625
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• 2022

In the field of imaging medicine, computed tomography is one of the most common test methods and one of the most frequently used test methods in hospitals. However, it is accompanied by a very high radiation exposure compared to other test methods. In order to reduce exposure, CT scans should be performed only when absolutely necessary, and even if the tests are performed because they are absolutely necessary, a protocol that serves the purpose of the test and allows the test to be performed in a small dose should be used. In this study, we wanted to learn about the most up-to-date radiation dose usage information used by the region's leading general hospitals and develop a diagnostic reference level (DRL). In the experimental results, the Head CT and Abdomen CT tests showed that DLP was higher than the NRPB (U.K) and Korean DRL. The DLP values used by Chest CT were low for all 3 types of CT devices. The hospital found that efforts to reduce exposure should be made during CT examinations, and in particular, Head CT and Abdomen CT determined that efforts to reduce exposure were necessary.

• Journal of Chest Surgery
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• v.42 no.2
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• pp.226-232
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• 2009

Background: Blunt chest trauma accounts for 90% of all chest traumas in Europe and the United States and this causes 20% of all trauma-related deaths. The major cause of morbidity and mortality after blunt chest trauma is undetected injuries. For this reason, chest computerized tomography has gained popularity for the evaluation of trauma, but it is expensive and it exposes patients to radiation. This study identified the clinical features associated with the diagnosic information obtained on a CT chest scan, as compared with a standard chest X-ray, for patients who sustained blunt trauma to the chest. This study also evaluated the role of a routine computed tomographic (CT) scan for these patients. The patients who had chest computed tomography done after the initial chest x-ray were analyzed separately for the presence of occult injuries. Material and Method: We studied 100 consecutive patients from November 2006 to July 2007: 74 patients after motor vehicle crashes and 26 patients after a fall from a height >2m. Simultaneous with the initial clinical evaluation, an anteroposterior chest radiograph and a helical chest CT scan were obtained for all the patients. The data extracted from the medical record included the vital signs, the interventions and the type and severity of injury (RTS). Result: Among the 100 cases, 79 patients showed at least more than one pathologic sign on their chest radiograph, and 21 patients had a normal chest radiograph. For 17 of the patients who had a normal chest X ray, the CT scan showed multiple injuries, which were pneumothorax, hemothorax, lung contusion, sternal fracture etc. This represents that a CT scan is statistically superior to a chest radiograph to diagnose the pathologic signs. But on the other hand, as for treatment, only 31 patients were diagnosed by CT scan and they were treated with chest tube insertion ect. 42 patients needed ony conservative management without invasive thoracosurgical treatment such as chest tube insertion or open thoracotomy. 27 patients were treated based on the diagnosis made by the chest radiograph and physical examination. Conclusion: Chest computerized tomography was significantly more effective than routine chest X-ray for detecting lung contusion, pneumothorax and mediastinal hematoma, as well as fractured ribs, scapula and, sternum. Although the occult findings increased, the number of patients who needed treatment was small. Therefore, we suggest making selective use of a CT scan to avoid its overuse in ERs.