• Korean Journal of Radiology
• /
• v.20 no.1
• /
• pp.50-57
• /
• 2019

In pediatric thoracic CT, respiratory motion is generally treated as a motion artifact degrading the image quality. Conversely, respiratory motion in the thorax can be used to answer important clinical questions, that cannot be assessed adequately via conventional static thoracic CT, by utilizing four-dimensional (4D) CT. However, clinical experiences of 4D thoracic CT are quite limited. In order to use 4D thoracic CT properly, imagers should understand imaging techniques, radiation dose optimization methods, and normal as well as typical abnormal imaging appearances. In this article, the imaging techniques of pediatric thoracic 4D CT are reviewed with an emphasis on radiation dose. In addition, several clinical applications of pediatric 4D thoracic CT are addressed in various thoracic functional abnormalities, including upper airway obstruction, tracheobronchomalacia, pulmonary air trapping, abnormal diaphragmatic motion, and tumor invasion. One may further explore the clinical usefulness of 4D thoracic CT in free-breathing children, which can enrich one's clinical practice.

• Journal of the Korean Society of Radiology
• /
• v.83 no.2
• /
• pp.265-283
• /
• 2022

To develop Korean coronavirus disease (COVID-19) chest imaging justification guidelines, eight key questions were selected and the following recommendations were made with the evidence-based clinical imaging guideline adaptation methodology. It is appropriate not to use chest imaging tests (chest radiograph or CT) for the diagnosis of COVID-19 in asymptomatic patients. If reverse transcription-polymerase chain reaction testing is not available or if results are delayed or are initially negative in the presence of symptoms suggestive of COVID-19, chest imaging tests may be considered. In addition to clinical evaluations and laboratory tests, chest imaging may be contemplated to determine hospital admission for asymptomatic or mildly symptomatic un-hospitalized patients with confirmed COVID-19. In hospitalized patients with confirmed COVID-19, chest imaging may be advised to determine or modify treatment alternatives. CT angiography may be considered if hemoptysis or pulmonary embolism is clinically suspected in a patient with confirmed COVID-19. For COVID-19 patients with improved symptoms, chest imaging is not recommended to make decisions regarding hospital discharge. For patients with functional impairment after recovery from COVID-19, chest imaging may be considered to distinguish a potentially treatable disease.

• Journal of Chest Surgery
• /
• v.31 no.3
• /
• pp.298-303
• /
• 1998

Computerized tomography(CT) is an effective technique in the initial evaluation of the abdomen and head following blunt trauma. To evaluate the efficacy of CT of the thorax, a retrospective study comparing early thoracic CT scanning with initial chest roentgenogram (CXR) was carried out on 134 patients with blunt trauma on the chest. Among 134 patients, 45 patients had normal initial chest roentgenogram and 24 patients showed normal CT findings. Sensitivities of diagnosing pneumothorax and pleural effusion by CXR were low (46.2 and 62.9% respectively), whereas 71.4%(45/63) of patients had thoracostomy only by CXR. Although sometimes abused, CT of the thorax is effective in the initial diagnosis.

• Journal of Yeungnam Medical Science
• /
• v.27 no.1
• /
• pp.57-62
• /
• 2010

Pulmonary alveolar proteinosis (PAP) is a rare disorder that's characterized by accumulation of surfactant components in the alveolar space. Idiopathic PAP is recognized as an autoimmune disease that's due to impaired alveolar macrophage function and this caused by autoantibodies against granulocyte-macrophage colony-stimulating factor (GM-CSF). We report here a case of pulmonary alveolar proteinosis that was deemed interstitial lung disease at the initial diagnosis. A 61-year-old man presented with intermittent blood tinged sputum and dyspnea on exertion. The man was a painter for 30 years and he had a 10 pack-years smoking history. Chest computerized tomography (CT) revealed multifocal ground-glass opacity with interstitial thickening at both lungs. His pulmonary function tests and methacholine test revealed non specific results. He was diagnosed with interstitial lung disease on the basis of the chest CT finding and occupational history. However, seven months later, his symptoms progressed. Follow-up chest CT was performed. Wedge resection via video-assisted thoracoscopic surgery (the anterior basal segment of the left lower lobe) was done. Microscopic examination showed large groups of alveoli with excessive amounts of surfactant and a complex mixture of protein and lipid (fat) molecules. Finally, he was diagnosed as having pulmonary alveolar proteinosis.

• Journal of radiological science and technology
• /
• v.40 no.4
• /
• pp.567-573
• /
• 2017

The purpose of this study was to evaluate whether or not there was artifact when the upper limb could not be lifted to the top of the head during multi-detector computed tomography(MDCT) scans of the chest and abdomen. Contrast radiography of the human and chest phantom was performed with 128channal MDCT. Under the same conditions(120 kVp, 110 mAs, standard algorithm)both hands lifted up and put down each time in the human experiment. In the chest phantom experiment, the radiography was carried out when the upper limb phantom was adjusted at a certain distance(0, 3, 7 cm) from the chest phantom. Subsequently, the values of Noise, CT number, SNR, and CNR were measured in the field of concern. The noise value of fat, rib, and muscle increased when the arm was lifted in humans(0.79, 47.8, 27%). Furthermore, when the upper limb was lowered, the noise value of muscle and lung increased in the phantom(31.2, 9.4%). In addition, the noise value of the muscles and lung decreased by 5, 25.12% and 5.6, 15.35% as the upper limb moved about 0,3,7cm away from the chest. When the chest and abdominal radiography were performed, in the case of the presence of other parts outside the inspection area, the probability of artifact was minimal while the distance was more than 3cm away from the upper limb to the chest and abdomen.

• Journal of the Korean Society of Radiology
• /
• v.5 no.5
• /
• pp.255-260
• /
• 2011

We wanted to evaluate the usefulness of three-dimensional reconstructive images using computed tomography for rib fracture patients. The reconstruction used in clinical multi planar reformation(MPR), volume rendering technique(VRT), and image data using quantitative methods and qualitative methods were compared. Much more, the artifact shadow was minimized to reconstruct with 3D volumetric image by using an law data in the analysis of the reconstructive image and chest CT scan of the evaluation result fractures of the thoracic patient. And we could know that the fractures of the thoracic determination and three dimension volume image reconstruction time were reduced.

• Journal of Chest Surgery
• /
• v.50 no.4
• /
• pp.308-311
• /
• 2017

A 71-year-old man was referred for an anterior chest wall mass. Chest computed tomography (CT) and positron emission tomography-CT suggested a malignant tumor. Surgical biopsy through a vertical subxiphoid incision revealed an extra-gastrointestinal stromal tumor (EGIST). En bloc resection of the tumor, including partial resection of the sternum, costal cartilage, pericardium, diaphragm, and peritoneum, was performed. Pathologic evaluation revealed a negative resection margin and confirmed the tumor as an EGIST. On postoperative day 17, the patient was discharged without any complications. At the 2-week follow-up, the patient was doing well and was asymptomatic.

• Journal of radiological science and technology
• /
• v.40 no.2
• /
• pp.229-235
• /
• 2017

In abdominal Ultrasonography, the fatty liver is diagnosed through hepatic parenchymal echo increased parenchymal density and unclear blood vessel boundary, and according to many studies, abdominal Ultrasonography has 60~90% of sensitivity and 84~95% of specificity in diagnosis of fatty liver, but the result of Ultrasonography is dependent on operators, so there can be difference among operators, and quantitative measurement of fatty infiltration is impossible. Among examinees who same day received abdominal Ultrasonography and chest computed tomography (CT), patients who were diagnosed with a fatty liver in the Ultrasonography were measured with liver Hounsfield Units (HU) of chest CT imaging to analyze the accuracy of the fatty liver diagnosis. Among 720 subject examinees, those who were diagnosed with a fatty liver through abdominal Ultrasonography by family physicians were 448, which is 62.2%. The result of Liver HU measurement in the chest CT imaging of those who were diagnosed with a fatty liver showed that 175 out of 720 had the measured value of less than 40 HU, which is 24.3%, and 173 were included to the 175 among 448 who were diagnosed through Ultrasonography, so 98.9% corresponded. This indicates that the operators' subjective ability has a great impact on diagnosis of lesion in Ultrasonography diagnosis of a fatty liver, and that in check up chest CT, under 40 HU in the measurement of Liver HU can be used for reference materials in diagnosis of a fatty liver.

• Korean Journal of Radiology
• /
• v.21 no.6
• /
• pp.736-745
• /
• 2020

Objective: To identify the initial chest computed tomography (CT) findings and clinical characteristics associated with the course of coronavirus disease 2019 (COVID-19) pneumonia. Materials and Methods: Baseline CT scans and clinical and laboratory data of 72 patients admitted with COVID-19 pneumonia (39 men, 46.2 ± 15.9 years) were retrospectively analyzed. Baseline CT findings including lobar distribution, presence of ground glass opacities, consolidation, linear opacities, and lung severity score were evaluated. The outcome event was recovery with hospital discharge. The time from symptom onset to discharge or the end of follow-up (for those remained hospitalized) was recorded. Data were censored in events such as death or discharge without recovery. Multivariable Cox proportional hazard regression was used to explore the association between initial CT, clinical or laboratory findings, and discharge with recovery, whereby hazard ratio (HR) values < 1 indicated a lower rate of discharge at four weeks and longer time until discharge. Results: Thirty-two patients recovered and were discharged during the study period with a median length of admission of 16 days (range, 9 to 25 days), while the rest remained hospitalized at the end of this study (median, 17.5 days; range, 4 to 27 days). None died during the study period. After controlling for age, onset time, lesion characteristics, number of lung lobes affected, and bilateral involvement, the lung severity score on baseline CT (> 4 vs. ≤ 4 [reference]: adjusted HR = 0.41 [95% confidence interval, CI = 0.18-0.92], p = 0.031) and initial lymphocyte count (reduced vs. normal or elevated [reference]: adjusted HR = 0.14 [95% CI = 0.03-0.60], p = 0.008) were two significant independent factors that influenced recovery and discharge. Conclusion: Lung severity score > 4 and reduced lymphocyte count at initial evaluation were independently associated with a significantly lower rate of recovery and discharge and extended hospitalization in patients admitted for COVID-19 pneumonia.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2009.01a
• /
• pp.794-798
• /
• 2009

We introduce an implementation of plug-ins on PLUTO. These plug-ins discriminate inflammatory nodules from other types of nodules in chest X-ray CT images. The PLUTO is a common platform for computer-aided diagnosis systems on Microsoft Windows series and it is easy to add new functions as plug-ins. We coded two plug-ins. One of the them calculates features based on medical knowledge. The other plug-in calculates parameters to classify the type of nodules, and it also classifies nodules into inflammatory nodules and others using SVM. These plug-ins are coded using MIST library which is produced at Nagoya University, Japan. In our previous study, the MIST library was parallelized, so that we can utilize a number of CPUs to calculate features and SVM learning/classifying depending on the amount of computation. Using these plug-ins, it became easy to extract features to discriminate inflammatory nodules from other types of nodules and to change parameters for feature extraction and SVM learning/classifying with GUI interface. The accuracy of the classifying result is 100% with 78 solid nodules which contains 43 inflammatory nodules and 35 other type of nodules.