• Journal of radiological science and technology
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• v.39 no.3
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• pp.329-336
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• 2016

The purpose of this study was to evaluate the usefulness of low-dose CT (LDCT) for emphysema compared with high-resolution CT (HRCT). Measurements of radiation dose and noise were repeated 3 times in same exposure condition which was similar with obtaining HRCT and LDCT images. We analysed reading results of 146 subjects. Six images per participants selected for emphysema grading. Emphysema was graded for all 6 zones on the left and right sides of the lungs by the consensus reading of two chest radiologists using a 4-point scale. Between the HRCT and LDCT images, diagnostic differences and agreements for emphysema were analyzed by McNemar's and unweighted kappa tests, and radiation doses and noise by a Mann-Whitney U-test, using the SPSS 19.0 program. Radiation dose from HRCT was significantly higher than that of LDCT, but the noise was significantly lower in HRCT than in LDCT. Diagnostic agreement for emphysema between HRCT and LDCT images was excellent (k-value=0.88). Emphysema grading scores were not significantly different between HRCT and LDCT images for all six lung zones. Emphysema grading scores from LDCT images were significantly correlated with increased scores on HRCT images (r=0.599, p < 0.001). Considering the tradeoff between radiation dose and image noise, LDCT could be used as the gold standard method instead of HRCT for emphysema detection and grading.

• Journal of radiological science and technology
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• v.27 no.3
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• pp.13-18
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• 2004

In most patients with facial palsy after temporal bone injury, temporal bone High Resolution CT revealed direct or indirect facial nerve canal involvement, and in complete palsy severe degeneration groups, there were direct findings in most cases. Author believe that meticulous analysis and symptom correlation of the fracture patterns seen in facial canal injury in patients with traumatic facial nerve palsy is helpful for treatment planning and prognosis.

• Tuberculosis and Respiratory Diseases
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• v.43 no.3
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• pp.367-376
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• 1996

Background : The diagnosis of emphysema during life is based on a combination of clinical, functional, and radiographic findings, but this combination is relatively insensitive and nonspecific. The development of rapid, high-resolution third and fourth generation CT scanners has enabled us to resolve pulmonary parenchymal abnormalities with great precision. We compared the chest HRCT findings to the pulmonary function test and arterial blood gas analysis in pulmonary emphysema patients to test the ability of HRCT to quantify the degree of pulmonary emphysema. Methods : From october 1994 to october 1995, the study group consisted of 20 subjects in whom HRCT of the thorax and pulmonary function studies had been obtained at St. Mary's hospital. The analysis was from scans at preselected anatomic levels and incorporated both lungs. On each HRCT slice the lung parenchyma was assessed for two aspects of emphysema: severity and extent. The five levels were graded and scored separately for the left and right lung giving a total of 10 lung fields. A combination of severity and extent gave the degree of emphysema. We compared the HRCT quantitation of emphysema, pulmonary function tests, ABGA, CBC, and patients characteristics(age, sex, height, weight, smoking amounts etc.) in 20 patients. Results : 1) There was a significant inverse correlation between HRCT scores for emphysema and percentage predicted values of DLco(r = -0.68, p < 0.05), DLco/VA(r = -0.49, p < 0.05), FEV1(r = -0.53, p < 0.05), and FVC(r = -0.47, p < 0.05). 2) There was a significant correlation between the HRCT scores and percentage predicted values of TLC(r = 0.50, p < 0.05), RV(r = 0.64, p < 0.05). 3) There was a significant inverse correlation between the HRCT scores and PaO2(r = -0.48, p < 0.05) and significant correlation with D(A-a)O2(r = -0.48, p < 0.05) but no significant correlation between the HRCT scores and PaCO2. 4) There was no significant correlation between the HRCT scores and age, sex, height, weight, smoking amounts in patients, hemoglobin, hematocrit, and wbc counts. Conclusion : High-Resolution CT provides a useful method for early detection and quantitating emphysema in life and correlates significantly with pulmonary function tests and arterial blood gas analysis.

• Journal of Chest Surgery
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• v.32 no.4
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• pp.383-387
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• 1999

Background: We analysed simple chest PA and high-resolution CT findings in patients with spontaneous pneumothorax in order to help selecting the kind of treatment, provide a guidline during surgical treatment, and to recognize the bulla which may not be detected by simple radiographs or may be a potential cause of recurrence. Material and Method: We retrospectively analysed the presence and number of bulla in each side, combined pulmonary disease on simple chest films and high-resolution CT, and methods and frequency of the treatment in 70 patients with spontaneous pneumothorax excluing traumatic origin. Result: 45 patients were revealed primary spontaneous pneumothorax, and the remaining 25 patients were revealed secondary spontaneous pneumothorax. All secondary spontaneous pneumothorax were from the longstanding sequelle of pulmonary tuberculosis. The patients with primary spontaneous pneumothorax group was younger(mean:26.0 years old) than secondary group (mean: 44.1 years old). On simple radiography, bulla was detected in 16 patients(30.2%). On HRCT, the bulla was detected in 53 patients(75.7%) of the total 70 patients. In 48 patients(68.6%), the bulla or bleb was noted in ipsilateral side to the pneumothorax, and 34 patients(48.6%) of them showed bulla or bleb bilaterally. 39 patients(55.7%) showed bulla or bleb in contralateral side. The number of bulla or bleb was variable. In secondary spontaneous pneumothorax group, the incidence of multiple(more than 10) bulla or bleb was higher than primary type. Most of the patients were treated by thoracostomy(36 patients) or bullectomy( 7 patients). Conclusion: HRCT was superior to detect bulla and analyse the combined pulmonary disease than simple radiography. Therefore, HRCT can help to determine the mothod of treatment, provide a guidline during surgical treatment, and notify the bulla as a possible cause of recurrent pneumothorax.

• Journal of the Korean Society of Radiology
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• v.84 no.6
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• pp.1290-1308
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• 2023

Purpose To compare the diagnostic performance of rectal CT with that of high-resolution rectal MRI and histopathology in assessing rectal cancer. Materials and Methods Sixty-seven patients with rectal cancer who underwent rectal CT with rectal distension using sonographic gel and high-resolution MRI were enrolled in this study. The distance from the anal verge/anorectal junction, distance to the mesorectal fascia (MRF), extramural depth (EMD), extramesorectal lymph node (LN) involvement, extramural venous invasion (EMVI), and T/N stages in rectal CT/MRI were analyzed by two gastrointestinal radiologists. The CT findings of 20 patients who underwent radical surgery without concurrent chemoradiotherapy were compared using histopathology. Interclass correlations and kappa statistics were used. Results The distance from the anal verge/anorectal junction showed an excellent intraclass correlation between CT and MRI for both reviewers. For EMD, the distance to the MRF, presence of LNs, extramesorectal LN metastasis, EMVI, T stage, and intermodality kappa or weighted kappa values between CT and MRI showed excellent agreement. Among the 20 patients who underwent radical surgery, T staging, circumferential resection margin involvement, EMVI, and LN metastasis on rectal CT showed acceptable concordance rates with histopathology. Conclusion Dedicated rectal CT may be on par with rectal MRI in providing critical information to patients with rectal cancer.

• Proceedings of the Korean Society of Computer Information Conference
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• 2019.01a
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• pp.465-467
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• 2019

본 논문에서는 영상생성이 가능한 딥러닝 네트워크를 이용하여 조영증강 CT 영상을 획득하는 연구를 수행하였다. CT는 고해상도 영상을 바탕으로 환자의 질병 및 암 세포 진단에 사용되는 의료영상 기법 중 하나이다. 특히, 조영제를 투여한 다음 CT 영상을 획득되는 영상을 조영증강 CT 영상이라 한다. 조영증강된 CT 영상은 물질의 구성 성분의 영상대비를 강조하여 임상의로 하여금 진단 및 치료반응 평가의 정확성을 향상시켜준다. 하지많은 수의 환자들이 조영제 부작용을 갖기 때문에 이에 해당되는 환자의 경우 조영증강 CT 영상 획득이 불가능해진다. 따라서 본 연구에서는 조영증강 영상을 얻지 못하는 환자 및 일반 환자의 불필요한 방사선의 노출을 최소화 하기 위하여 영상생성 딥러닝 기법을 이용하여 CT 영상에서 조영증강 CT 영상을 생성하는 연구를 진행하였다. 영상생성 딥러닝 네트워크는 generative adversarial network (GAN) 모델을 사용하였다. 연구결과 아무런 전처리도 거치지 않은 CT 영상을 이용하여 영상을 생성하는 것 보다 히스토그램 균일화 과정을 거친 영상이 더 좋은 결과를 나타냈으며 생성영상이 기존의 실제 영상과 영상의 구조적 유사도가 높음을 확인할 수 있다. 본 연구결과 딥러닝 영상생성 모델을 이용하여 조영증강 CT 영상을 생성할 수 있었으며, 이를 통하여 환자의 불필요한 방사선 피폭을 최소하며, 생성된 조영증강 CT 영상을 바탕으로 정확한 진단 및 치료반응 평가에 기여할 수 있을거라 기대된다.

• Tuberculosis and Respiratory Diseases
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• v.43 no.5
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• pp.746-754
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• 1996

Objective: Diffuse interstitial lung disease (DILD) is a group of diverse diseases that share conUTIon clinical, radiologic, and pulomonary function features. Open lung biopsy (OLB) has been regarded as gold standard in differential diagnosis of DILD. However open lung biopsy is a invasive diagnostic tool not free of its own risk or complications. These days, high-resolution computed tomography (HRCf) has become an important diagnostic tool in DILD through its precise image analysis. In many instances, HRCT could provide specific diagnosis or, at least, provide infonnation on the disease activity of DILD. The authors re-evaluate the role of open lung biopsy in this "HRCT era" by investigating the additional diagnostic gain and impacts on the treannent plan in patients who have undergone high-resolution CT. Method : Diagnoses obtained by high-resolution CT and open lung biopsy were compared and changes of treatment plans were evaluated retrospectively in 30 patients who had undergone open lung biopsy for the purpose of diagnosis of diffuse interstitial lung disease from March 1988 to June 1994. Results : High-resolution cr suggeted specific diagnoses in 22 out of 28 patients (78.6%) and the diagnoses were confinned (0 be correct by open lung biopy in 20 of those 22 cases (91%). Open lung biopsy could not give specific diagnosis in 5 out of 30 cases (16.7%). In 5 out of 6 cases (83.3%) in whom high reolution cr was not able to suggest specific diagnosis, open lung biopsy gave specific diagnoses. Treatment plan was altered by the result of open lWlg biopsy in only 2 cases. Conclusion: The aoove fmdings suggest that in "HRCT era", when HRCT could suggest specific diagnosis, the need for open lung biopsy should be re-evaluated.

• Investigative Magnetic Resonance Imaging
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• v.13 no.2
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• pp.190-194
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• 2009

Generalized lymphangiomatosis is a rare congenital malformation of the lymphatics. CT and MR scan have been used to evaluate lymphangiomas, which appear as large multicystic fluid-filled masses. CT and MR Imaging findings are often helpful in distinguishing lymphangiomas from various vascular disorders. We report the findings of CT, MRI and bone scan in a patient with generalized cystic lymphangiomatosis. Whole body 3.0-T MR scan using STIR sequence with a larger FOV could detect the additional lesions that were not seen at other imaging modalities. We believe that whole body 3.0 T MR imaging is a good modality to evaluate the extent of the disease and following up the patients with the generalized cystic lymphangiomatosis.

• Tuberculosis and Respiratory Diseases
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• v.47 no.1
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• pp.66-76
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• 1999

Background : To assess the utility of HRCT in the evaluation of visceral pleural invasion and to determine whether visceral pleural invasion and bronchovascular bundle thickening on the same lobe could be related to the recurrence and survival in non-small cell lung cancer (NSCLC) Method: Eighty one patients, which were fulfilled long-term follow-up at least 18 months (maximum 103 months) among which 434 patients had underwent curative surgical resection for NSCLC from 1986 to 1995, were studied. They were analyzed to evaluate whether the prognostic factors such as the recurrence and survival depend on visceral pleural invasion and bronchovascular bundle thickening to the same lobe. Thirty two patients adjacent to a chest wall or a fissure were evaluated for visceral pleural invasion by HRCT. CT criteria included abutting pleura along the chest wall, abutting and/or compressing fissure, croosing fissure, and pleural tail. Results: The positive predictive value and the negative predictive value of crossing fissure were 100% and 100%, respectively. Two patients showing spiculated interface between a mass and abutting fissure were confirmed to have visceral pleural invasion at surgery. Visceral pleural invasion confirmed at surgery was significant to local recurrence and survival (p<.05. p<.05, respectively). Brochovascular bundle thickening to the same lobe on CT scan was significant to survival (p<.05) but was not significant to local and distant recurrence (p>.05). Conclusion : Visceral pleural invasion and bronchovascular bundle thickening to the same lobe have a role in predicting prognosis such as recurrence and survival in NSCLC. Therefore, the analysis of visceral pleural invasion on CT scan and the pathological analysis of bronchovascular bundle thickening to the same lobe may be necessary to predict the prognosis in NSCLC.

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