Sung Shine Shim

Thoracic Actinomycosis: CT Features with Histopathologic Correlation

OBJECTIVE Thoracic actinomycosis is a chronic suppurative pulmonary or endobronchial infection caused by Actinomyces israelii, a gram-positive anaerobic organism. We present the CT features of thoracic actinomycosis with histopathologic correlation. CONCLUSION The typical CT feature of parenchymal actinomycosis is a chronic segmental air-space consolidation containing necrotic low-attenuation areas with frequent cavity formation. A broncholith can be secondarily infected with Actinomyces organisms, resulting in endobronchial actinomycosis. It usually manifests as a proximal endobronchial calcification associated with distal obstructive pneumonia.

Efficacy of Helical Dynamic CT Versus Integrated PET/CT for Detection of Mediastinal Nodal Metastasis in Non-Small Cell Lung Cancer

OBJECTIVE The purpose of our study was to compare the diagnostic efficacies of helical dynamic CT and integrated PET/CT for the prediction of mediastinal nodal metastasis in stage T1 non-small cell lung cancer (NSCLC). MATERIALS AND METHODS One hundred forty-three patients with stage T1 NSCLC underwent both helical dynamic CT and integrated PET/CT followed by surgical nodal staging. In helical dynamic CT, patients were regarded to have stage N2 disease when a nodule showed a peak enhancement > or = 110 H or a net enhancement > or = 60 H. In integrated PET/CT, nodes were regarded as positive for malignancy when they showed > or = 3.5 in maximum standardized uptake value with a discrete margin and more 18F-FDG uptake than mediastinal structures. Sensitivities, specificities, and accuracies for mediastinal nodal metastasis detection were compared for helical dynamic CT and integrated PET/CT using the McNemar test. RESULTS Of the 143 patients, 34 (24%) had positive mediastinal nodes. The sensitivity, specificity, and accuracy for mediastinal nodal metastasis prediction on helical dynamic CT were 65% (22 of 34 patients), 89% (97 of 109), and 83% (119 of 143), respectively, whereas those on integrated PET/CT were 56% (19 of 34), 100% (109 of 109), and 90% (128 of 143). The p values were 0.664, < 0.001, and 0.015. CONCLUSION In stage T1 NSCLC, contrast-enhanced helical dynamic CT better predicts, but not significantly so, mediastinal nodal metastasis than PET/CT, whereas PET/CT shows perfect specificity and higher accuracy than helical dynamic CT.

Integrated PET/CT and the dry pleural dissemination of peripheral adenocarcinoma of the lung: diagnostic implications.

Objective: The aim of this study was to describe retrospectively the CT findings of dry pleural dissemination of peripheral lung adenocarcinoma, and to compare the mutual roles of PET and CT components of integrated PET/CT in the diagnosis of the disease. Methods: The authors analyzed retrospectively the CT findings of pathologically proved dry pleural dissemination in 8 of 172 patients with peripheral adenocarcinoma of the lung. Subsequently, one radiologist and one nuclear medicine physician (unaware of the CT and pathologic results) evaluated together in a random order the integrated PET/CT of 172 adenocarcinoma patients (8 with dry pleural dissemination and 164 without). They recorded the presence of pleural dissemination using PET images only and using both PET and CT images. The diagnostic accuracies with respect to the presence of pleural dissemination were evaluated. Results: The CT findings of dry pleural dissemination were pleural small nodules (n = 8, 100%) (≥6 in number in all patients; 198/204 nodules were <5 mm in diameter and 6/204 were 5-10 mm) and uneven (n = 4, 50%) or band-like (n = 3, 38%) fissural thickening. By PET only, the sensitivity, specificity, and accuracy of dry pleural dissemination were 25% (2/8), 90% (147/164), and 87% (149/172), respectively; by PET plus CT these were 100% (8/8), 100% (164/164), and 100% (172/172), respectively. Conclusions: The CT findings of dry pleural dissemination are multiple small pleural nodules and uneven pleural thickening. Dry pleural dissemination should be diagnosed using CT findings at integrated PET/CT because lesions causing pleural dissemination without pleural effusion are usually beyond PET resolution.

Combined Fluoroscopy- and CT-Guided Transthoracic Needle Biopsy Using a C-Arm Cone-Beam CT System: Comparison with Fluoroscopy-Guided Biopsy

Objective The aim of this study was to evaluate the usefulness of combined fluoroscopy- and CT-guided transthoracic needle biopsy (FC-TNB) using a cone beam CT system in comparison to fluoroscopy-guided TNB (F-TNB). Materials and Methods We retrospectively evaluated 74 FC-TNB cases (group A) and 97 F-TNB cases (group B) to compare their respective diagnostic accuracies according to the size and depth of the lesion, as well as complications, procedure time, and radiation dose. Results The sensitivity for malignancy and diagnostic accuracy for small (< 30 mm in size) and deep (≥ 50 mm in depth) lesions were higher in group A (91% and 94%, 92% and 94%) than in group B (73% and 81%, 84% and 88%), however not statistically significant (p > 0.05). Concerning lesions ≥ 30 mm in size and < 50 mm in depth, both groups displayed similar results (group A, 91% and 92%, 80% and 87%; group B, 90% and 92%, 86% and 90%). Pneumothorax occurred 26% of the time in group A and 14% for group B. The mean procedure time and patient skin dose were significantly higher in group A (13.6 ± 4.0 minutes, 157.1 ± 76.5 mGy) than in group B (9.0 ± 3.5 minutes, 21.9 ± 15.2 mGy) (p < 0.05). Conclusion Combined fluoroscopy- and CT-guided TNB allows the biopsy of small (< 30 mm) and deep lesions (≥ 50 mm) with high diagnostic accuracy and short procedure times, whereas F-TNB is still a useful method for large and superficial lesions with a low radiation dose.

Transthoracic needle biopsy using a C-arm cone-beam CT system: diagnostic accuracy and safety

OBJECTIVE The purpose of this study was to evaluate the diagnostic accuracy and safety of performing transthoracic needle biopsy (TNB) under combined fluoroscopy and CT guidance using a C-arm cone-beam CT (CBCT) system. METHODS We evaluated the diagnostic accuracy and safety of performing TNB using a C-arm CBCT system. We retrospectively evaluated 99 TNB cases performed in 98 patients using a C-arm CBCT system with an 18-gauge automated cutting needle. We reviewed the diagnostic accuracy according to the size and depth of the lesion, incidence of complications, additional treatment for complications, procedure time, number of needle passes per biopsy and radiation dose. RESULTS The final diagnoses revealed 72 malignant and 27 benign lesions. The overall malignancy sensitivity, malignancy specificity and diagnostic accuracy were 95.8%, 100% and 97.0%, respectively, and those for small pulmonary nodules <20 mm in size were 94.1%, 100% and 96.6%, respectively. There was no significant difference in the correct diagnosis of malignancy according to lesion size (p = 0.634) or depth (p = 0.542). For benign lesions, a specific diagnosis was obtained in 14 cases (51.9%). TNB induced complications in 19 out of 99 procedures (19.2%), including pneumothorax (16.2%), immediate haemoptysis (2.0%) and subcutaneous emphysema (1.0%). Among these, four patients with pneumothorax required chest tube insertion (2.0%) or pig-tail catheter drainage (2.0%). The mean procedure time, number of needle passes and radiation doses were 11.9 ± 4.0 min, 1.2 ± 0.5 times and 170.0 ± 67.2 mGy, respectively. CONCLUSION TNB using a C-arm CBCT system provides high diagnostic accuracy with a low complication rate and a short procedure time, particularly for small pulmonary nodules.

Coronary Artery Disease in Asymptomatic Young Adults: Its Prevalence According to Coronary Artery Disease Risk Stratification and the CT Characteristics

Objective We aimed at evaluating the prevalence and CT characteristics of occult coronary artery disease (CAD) in young Korean adults under 40 years of age by performing coronary CT angiography (CCTA). Materials and Methods We retrospectively enrolled 112 consecutive asymptomatic subjects (90 men, mean age: 35.6 ± 3.7 years) who underwent CCTA as part of a general health evaluation. We classified the subjects into three National Cholesterol Education Program risk categories and we assessed the plaque characteristics on CCTA according to the number of involved vessels, the location and type of plaques and vascular remodeling. Results Twelve individuals had CAD (11%, 11 men). The prevalence of CAD was significantly higher in the subgroups with moderate (22%) or high (25%) risk than that in the low risk subgroup (5%) (p < 0.05). Nine patients had single-vessel disease and three patients had two-vessel disease. The most common location for plaque was the proximal left anterior descending coronary artery (60%). All the patients had non-significant stenosis and plaque, including the non-calcified (27%), mixed (47%) and calcified (27%) types. Positive vascular remodeling was identified in all the patients with non-calcified or mixed plaques. Conclusion The prevalence of occult CAD was not negligible in the asymptomatic young adults with moderate to high risk, and this suggests the importance of management and risk factor modification in this population. All the patients had non-significant stenosis, and one fourth of the plaques did not show calcification.

Thoracic Complications of Liver Cirrhosis: Radiologic Findings

Patients with chronic liver disease exhibit various cardiovascular and pulmonary complications. Hepatopulmonary syndrome results in dyspnea due to intrapulmonary arteriovenous shunting and ventilation-perfusion mismatch. Portopulmonary hypertension occurs in patients with portal hypertension. Intrathoracic portosystemic collateral vascular pathways develop in patients with portal hypertension to allow decompression of the portal vein into the systemic circulation. Hepatic hydrothorax may develop in patients with cirrhosis and ascites. Massive necrosis of the liver from any cause may be associated with acute hypoxic respiratory failure, necessitating ventilatory support. Bacterial infection is common in cirrhotic patients because of a compromised host defense system. Hepatocellular carcinoma may produce hematogenous lung metastases, intrathoracic lymph node metastases, direct intracardiac extension, and pulmonary embolism. Interferon therapy for treatment of chronic active hepatitis C may disturb cellular immune activation in some patients and contribute to the onset and progression of sarcoidosis. Awareness of the various thoracic manifestations in chronic liver disease can be helpful for making a differential diagnosis and planning proper management.

Novel influenza A (H1N1) infection: chest CT findings from 21 cases in Seoul, Korea

AIM To retrospectively evaluate the computed tomography (CT) appearances of novel influenza A (H1N1) infection. MATERIALS AND METHODS Chest CT images obtained at clinical presentation in 21 patients (eight men, 13 women; mean age, 37 years; age range, 6-82 years) with confirmed novel influenza A (H1N1) infection were assessed. The radiological appearances of pulmonary parenchymal abnormalities, distribution, and extent of involvement on initial chest CT images were documented. The study group was divided on the basis of age [group 1, patients <18 years old (n=8); group 2, patients ≥ 18 years old (n=13)]. Medical records were reviewed for underlying medical conditions and laboratory findings. The occurrence of recognizable CT patterns was compared for each group using the images from the initial CT examination. RESULTS The most common CT pattern observed in all patients was ground-glass attenuated (GGA) lesions (20/21, 95%). Bronchial wall thickening (9/21, 43%) was the second most common CT finding. Other common CT findings were consolidation (6/21, 29%), pleural effusion (6/21, 29%), pneumothorax or pneumomediastinum (5/21, 24%), and atelectasis (5/21, 24%). Among these, atelectasis and pneumomediastinum (pneumothorax) were only observed in group 1. The GGA lesions showed predilections for diffuse multifocal (10/20, 50%) or lower zone (8/20, 40%) distribution. Involvement of central lung parenchyma (12/20, 60%) was more common than a mixed peripheral and central pattern (6/20, 30%) or a subpleural pattern (2/20, 10%) at the time of presentation. Patchy GGA lesions were more frequent (18/20, 90%) than diffuse GGA lesions, and 75% (15/20) of these lesions had a bronchovascular distribution. Bilateral disease was present in all patients with GGA lesions. Bronchial wall thickening was predominantly centrally located and the distribution of the consolidation was non-specific. CONCLUSION The predominantly centrally located GGA lesions, with common multifocal or bilateral involvement, peribronchovascular distribution, and patchy appearance are the more distinctive CT findings of novel influenza A (H1N1) infection. Pneumomediastinum and atelectasis resulting from this disease are more common in young patients under the age of 18 years.

Risk factors for pulmonary complications, including pulmonary embolism, after total knee arthroplasty (TKA) in elderly Koreans

There has been a steady increase in elective TKA in elderly Koreans. However, there are few reports about the incidence of and risk factors for pulmonary complications, including pulmonary thromboembolism in these patients. We evaluated retrospectively 338 patients aged 60 years and over (290 females, median age 69 years) to assess the incidence and predictive factors for pulmonary complications, including pulmonary thromboembolism after TKA. Of these patients, 264 underwent simultaneous bilateral TKA (78%) by two surgeons and 56 (17%) had general anesthesia. No patient received thromboprophylaxis. There were 49 postoperative pulmonary complications in the 338 patients (14.2%, 49/338). Of the 49 patients, 27 developed atelectasis (27/49), six developed pneumonia (6/49), and four had pleural effusions (4/49) within 7 days of the surgery; 12 patients had a pulmonary thromboembolism (12/49) during their hospitalization. No pulmonary complication was fatal. Multivariate analysis revealed that pulmonary hypertension (right ventricular systolic pressure≥35 mmHg on transthoracic echocardiography; odds ratio (OR)=3.0, p=0.016) was independently associated with pulmonary complications. A resting PaCO(2)≥45 mmHg (OR=22.9, p=0.004) was the only independent predictor of the development of a pulmonary thromboembolism. Pulmonary hypertension may thus predict pulmonary complications and a PaCO(2) greater than 45 mmHg may be a risk factor for pulmonary thromboembolism following TKA. Preoperative blood gas analysis and transthoracic echocardiography can identify those patients at high risk for pulmonary complications, including pulmonary thromboembolism, after TKA in elderly Korean patients.

Pleuropulmonary and abdominal paragonimiasis: CT and ultrasound findings.

OBJECTIVES The purpose of this study was to review radiological images of patients with Paragonimus westermani (PW) that simultaneously involved the chest and abdomen. METHODS Our study included four patients with serologically and histopathologically confirmed paragonimiasis. Abdomen CT (n=3) and chest CT (n=3) scans were available, and abdominal wall ultrasonography was performed in all patients. We retrospectively reviewed the clinical, radiological and histopathological findings of these patients. RESULTS The most common abdominal CT findings were ascites and intraperitoneal or abdominal wall nodules. Low-attenuated serpentine lesions of the liver were another common and relatively specific feature. CONCLUSION Radiologists should consider the possibility of PW when these abdominal CT findings are noted, especially with pleural effusion or subpleural nodules in patients with initial abdominal symptoms.