Biomedical subjects

Young Cheol Yoon

Publications and source records attributed to Young Cheol Yoon.

9 recordsLinked to original sources

PubMed2006

Bronchial and nonbronchial systemic arteries in patients with hemoptysis: depiction on MDCT angiography.

OBJECTIVE: In this pictorial essay, we show the usefulness of MDCT angiography for visualization of the bronchial and nonbronchial systemic feeder vessels responsible for hemoptysis. CONCLUSION: By providing thin-section transaxial, multiplanar reconstruction, and 3D images, CT angiography using MDCT allows comparable or better images than conventional angiography with respect to the depiction of bronchial or nonbronchial systemic arteries. CT angiography is particularly useful for visualizing the ectopic origin of bronchial arteries and nonbronchial systemic collateral arteries.

Adult↗

PubMed2004

Hemoptysis: bronchial and nonbronchial systemic arteries at 16-detector row CT.

PURPOSE: To retrospectively evaluate 16-detector row computed tomography (CT) compared with conventional angiography in depiction of bronchial and nonbronchial systemic arteries in patients with hemoptysis. MATERIALS AND METHODS: Institutional review board approval was obtained, and informed consent was not required. Sixteen-detector row helical CT and conventional angiography of the thorax were performed in 22 patients (16 men, six women; age range, 18-75 years; mean age, 50 years) with hemoptysis. Three observers in consensus analyzed retrospectively transverse, multiplanar reconstruction, or three-dimensional CT images for visibility, traceability of bronchial arteries from their origin at the aorta or aortic branches to the hilum, and presence of nonbronchial systemic arteries. CT and angiographic findings of bronchial and nonbronchial systemic arteries causing hemoptysis were compared by two radiologists in consensus. Differences in visibility, traceability, and diameter of bronchial arteries causing and those not causing hemoptysis were tested by using generalized estimating equation method or the mixed model. RESULTS: Fifty-two (30 right and 22 left) bronchial arteries and 33 nonbronchial systemic arteries were visible at CT. Thirty-four (20 right and 14 left) of 52 bronchial arteries were traceable from their origins to the hilum. Thirty-one (16 right and 15 left) of 46 (27 right and 19 left) bronchial arteries and 26 of 64 nonbronchial systemic arteries evaluated at angiography were causing hemoptysis. Forty (87%, 23 right and 17 left) of 46 bronchial arteries seen at angiography were also detected at CT. All 31 bronchial arteries and sixteen (62%) of 26 nonbronchial systemic arteries causing hemoptysis were detected at CT. Twenty-three (74%) of 31 bronchial arteries causing hemoptysis were traceable from their origins to the hilum, and one (11%) of nine bronchial arteries not causing hemoptysis was traceable (P = .002). CONCLUSION: Sixteen-detector row CT provides depiction and traceability of the bronchial arteries in patients with hemoptysis, and in most patients it enables detection of the bronchial and nonbronchial arteries causing hemoptysis.

Adolescent↗

PubMed2003

Metastasis to regional lymph nodes in patients with esophageal squamous cell carcinoma: CT versus FDG PET for presurgical detection prospective study.

PURPOSE: To prospectively compare the accuracy of fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) and computed tomography (CT) for detection of primary tumor and metastasis to individual lymph node groups and for nodal staging. MATERIALS AND METHODS: From February 2000 to July 2001, 81 patients with squamous cell carcinoma of the esophagus (78 men and three women; age range, 31-90 years; mean age, 63 years) underwent CT and FDG PET before esophagectomy and lymph node dissection. During surgery, all visible and palpable lymph nodes in the surgical fields were removed. The accuracies of CT and FDG PET for depiction of metastasis to lymph nodes were compared. RESULTS: For depiction of malignant nodal groups in each lymph node group, the sensitivity, specificity, and accuracy, respectively, of CT were 11% (11 of 96 nodal groups), 95% (553 of 581), and 83% (564 of 677), whereas those of FDG PET were 30% (29 of 96), 90% (525 of 581), and 82% (554 of 677) (P values: < .001, .009, and .382, respectively). Twenty-eight false-positive interpretations were rendered at CT in evaluations of 11 mediastinal, four hilar, and 13 abdominal nodal groups, and 56 false-positive interpretations were rendered at FDG PET in evaluations of 23 mediastinal, 32 hilar, and one abdominal nodal group. CONCLUSION: FDG PET is more sensitive than CT for depicting nodal metastases in patients with squamous cell carcinoma of the esophagus. FDG PET is slightly less specific than CT for depicting metastases, but the difference in specificity between the two modalities is statistically significant. Both FDG PET and CT have low sensitivity for depicting nodal metastasis. The relatively low specificity of FDG PET for depiction of nodal metastasis compared with that of CT is caused mainly by a high rate of false-positive hilar node interpretations.

Carcinoma, Squamous Cell↗

PubMed2003

Reversed halo sign on high-resolution CT of cryptogenic organizing pneumonia: diagnostic implications.

OBJECTIVE: The aim of our study was to evaluate the usefulness of the reversed halo sign on high-resolution CT in the diagnosis of cryptogenic organizing pneumonia. MATERIALS AND METHODS: Between 1996 and 2001, we saw 31 patients with biopsy-proven cryptogenic organizing pneumonia. During the same period, we also saw 30 patients with non-cryptogenic organizing pneumonia diseases, from which cryptogenic organizing pneumonia should be differentiated: Wegener's granulomatosis (n = 14), diffuse bronchioloalveolar carcinoma (n = 10), chronic eosinophilic pneumonia (n = 5), and Churg-Strauss syndrome (n = 1). Two independent observers analyzed CT findings and recorded how frequently the so-called reversed halo sign (central ground-glass opacity and surrounding air-space consolidation of crescentic and ring shape) was seen on high-resolution CT. RESULTS: The most common patterns of parenchymal abnormalities of cryptogenic organizing pneumonia were ground-glass opacity (28/31 patients, 90%) and consolidation (27/31, 87%). The ground-glass opacity pattern showed random distribution, and the consolidation pattern showed subpleural or peribronchovascular (20/27 patients, 74%) distribution with predominance in the middle or lower lung zone. The reversed CT halo sign was seen in six (19%) of 31 patients with cryptogenic organizing pneumonia and in none of the patients with the diseases that needed to be differentiated from cryptogenic organizing pneumonia on CT. CONCLUSION: The reversed halo sign, although seen only in one fifth of patients with the disease, appears relatively specific to make a diagnosis of cryptogenic organizing pneumonia on CT.

Adult↗

PubMed2003

Imaging-guided percutaneous radiofrequency ablation of pulmonary metastatic nodules caused by hepatocellular carcinoma: preliminary experience.

OBJECTIVE: The purpose of our study was to evaluate the efficacy of imaging-guided percutaneous radiofrequency ablation of metastatic pulmonary nodules caused by hepatocellular carcinoma. CONCLUSION: Percutaneous radiofrequency ablation is feasible and can be a promising method for the local control of metastatic pulmonary nodules caused by hepatocellular carcinoma, especially when they are limited in number.

Adult↗

PubMed2002

Intrapulmonary bronchogenic cyst: CT and pathologic findings in five adult patients.

OBJECTIVE: The purpose of our study was to describe the CT and pathologic findings of intrapulmonary bronchogenic cysts in five adult patients. CONCLUSION: Intrapulmonary bronchogenic cysts in adults appear on CT as well-defined ovoid lesions with the attenuation of soft tissue or water, similar to their mediastinal counterparts. Associated with these cysts are areas of mosaic low attenuation and bandlike linear attenuation representing histopathologically confirmed emphysema and bronchiolization or fibrotic change or both in the surrounding lung.

Adult↗

PubMedDate not supplied

Benign bronchopulmonary tumors: radiologic and pathologic findings.

According to the new World Health Organization classification, benign bronchopulmonary tumors can be classified into epithelial tumors, mesenchymal tumors, and tumor-like conditions. Imaging findings of benign tumors of large airways are nonspecific and overlapping. Some benign pulmonary tumors show characteristic imaging findings. On CT, bronchioloalveolar adenomas appear as a small nodular area of ground-glass opacity. Metastasizing leiomyomas are seen as well-circumscribed solitary or multiple pulmonary nodules ranging in size from a few millimeters to several centimeters. Pulmonary hamartomas or lipomas are recognized specifically when fat deposits of CT number in the -80 HU to -120 HU range are identified. Enhancement of tumor with administration of contrast medium with or without foci of calcification may be seen in sclerosing hemangiomas and hemangiopericytomas. Awareness of the various imaging findings of these tumors can help narrow down the differential diagnosis on daily practice among the long lists of bronchopulmonary tumors.

Adult↗

PubMedDate not supplied

Additional coronal images using low-milliamperage multidetector-row computed tomography: effectiveness in the diagnosis of bronchiectasis.

PURPOSE: The aim of our study was to evaluate the effectiveness of additional coronal images using low-milliamperage multidetector-row computed tomography (CT) in the diagnosis of bronchiectasis. METHODS: Helical volumetric CT scans (120 kVp, 70 mA, 2.5-mm collimation, table speed of 15 mm/s, table rotation time of 1 second) using low-milliamperage multidetector-row CT were obtained through the thorax in 110 patients who were suspected of bronchiectasis. Both axial (2.5-mm section thickness) and coronal (1.3-2.0-mm section thickness) reformatted images were made and sent to picture archiving and communication system (PACS) monitors. Two independent observers assessed CT scans twice; with axial images only and with both axial and coronal images. The detection rates of bronchiectasis were compared between readings with axial images only and with both axial and coronal images by using a nonparametric method of clustered data. Confidence grades were given to the distribution and type of bronchiectasis. RESULTS: With axial images only, the detection rates of bronchiectasis on a per-patient basis were 97% (213/220 patients, kappa = 0.888) whereas with both axial and coronal images, the detection rates were 100% (220/220 patients, kappa = 1.000) (P = 0.0001). Confidence to the distribution of bronchiectasis was greater with both axial and coronal images than with axial images only (P = 0.008). CONCLUSIONS: Additional coronal images using low-milliamperage multidetector-row CT are effective in the diagnosis of bronchiectasis by providing enhanced detection rates and confidence to the distribution of lesions.

Adult↗

PubMedDate not supplied

Evaluation of small pulmonary arteries by 16-slice multidetector computed tomography: Optimum slab thickness in condensing transaxial images converted into maximum intensity projection images.

OBJECTIVE: The purpose of this study was to determine the optimal slab thickness for condensing transaxial images into maximum intensity projection (MIP) images in the evaluation of small pulmonary arteries using 16-slice multidetector-row computed tomography (MDCT). METHODS: Helical computed tomography (CT) scans were obtained from lung apices to bases using 16-slice MDCT [120 kV(peak), 180 mA, beam width of 10 mm, beam pitch of 1.375, and reconstruction thickness of 1.25 mm] in 29 patients suspected of having a pulmonary embolism. Four kinds of image series (1.25-mm thick original transaxial source images and 3 kinds of reconstructed images using the MIP technique with slab thicknesses of 2.5 mm, 5 mm, and 10 mm) were obtained from each patient and forwarded to monitors of a picture archiving and communication system for analysis by 2 independent observers. The observers recorded the name of the segmental (20 total; 10 in each lung) and subsegmental (40 total; 20 in each lung) arteries that were traceable in each image series. Image quality of the 4 image types were graded into 5 scales based on their degree of vascular opacification, the sharpness of the vascular margins of the contrast-enhanced CT angiograms, and the visibility of lung parenchyma (excellent [5] to nondiagnostic [1]) and compared. RESULTS: In both the 1.25-mm thick original transaxial and 2.5-mm thick MIP images, a higher percentage of subsegmental arteries was traceable (91.3% [2119/2320 observations] and 87.2% [2023/2320 observations], respectively; P <0.05) than in the 5-mm and 10-mm thick MIP images (66.4% [1540/2320] and 40.5% [940/2320], respectively). No statistically significant difference was observed between the 1.25-mm thick transaxial and 2.5-mm thick MIP images in this respect. Image quality of 2.5-mm thick MIP images was superior to that of the 5-mm and 10-mm thick MIP images (P < 0.0001). No statistically significant difference was found between the scores of the image quality of the 1.25-mm thick original transaxial images and the 2.5-mm thick MIP images. CONCLUSION: After reducing the image number by one half, 2.5-mm thick MIP images using 16-slice MDCT are found to provide satisfactory images, which are comparable to 1.25-mm thick transaxial images for the analysis of subsegmental pulmonary arteries in patients suspected of pulmonary embolism.

Adult↗