Simple quantification of paracardial and epicardial fat dimensions at low-dose chest CT: correlation with metabolic risk factors and usefulness in predicting metabolic syndrome.

PURPOSE: To assess the usefulness of simple axial bi-dimensional diameters of pericardial fat tissues at low-dose chest CT, in correlation with metabolic parameters in predicting metabolic syndrome. MATERIALS AND METHODS: Subjects were 373 asymptomatic individuals who performed both low-dose chest CT and abdominal fat CT for medical check-up. Maximum bi-dimensional axial diameters of paracardial fats at right (RPF) and left (LPF) cardiophrenic angle portions, and epicardial fats around right (REF) and left (LEF) coronary arteries, and coronary sinus (SEF) were measured. Correlation between pericardial fat diameters and metabolic parameters were statistically analyzed. RESULTS: RPF, LPF, REF, LEF, and SEF diameters were moderately correlated with abdominal visceral fat (AVF) area (R = 0.74, 0.70, 0.48, 0.41, and 0.53, respectively, p < 0.01) in Pearson's correlation analysis. In multiple linear regression analysis, coefficient of RPF for AVF showed highest value. Means of each PF and EF diameters in subjects with metabolic syndrome were significantly larger than those without metabolic syndrome (p < 0.001). All PF and EF diameters were well-discriminated for prediction of metabolic syndrome in ROC analysis (AUC values, from 0.696 to 0.795). CONCLUSION: RPF diameter at low-dose chest CT would be a simple method for prediction of metabolic syndrome.

Are Lung Imaging Reporting and Data System Categories Clear to Radiologists? A Survey of the Korean Society of Thoracic Radiology Members on Ten Difficult-to-Classify Scenarios.

OBJECTIVE: To evaluate possible variability in chest radiologists' interpretations of the Lung Imaging Reporting and Data System (Lung-RADS) on difficult-to-classify scenarios. MATERIALS AND METHODS: Ten scenarios of difficult-to-classify imaginary lung nodules were prepared as an online survey that targeted Korean Society of Thoracic Radiology members. In each question, a description was provided of the size, consistency, and interval change (new or growing) of a lung nodule observed using annual repeat computed tomography, and the respondent was instructed to choose one answer from five choices: category 2, 3, 4A, or 4B, or "un-categorizable." Consensus answers were established by members of the Korean Imaging Study Group for Lung Cancer. RESULTS: Of the 420 answers from 42 respondents (excluding multiple submissions), 310 (73.8%) agreed with the consensus answers; eleven (26.2%) respondents agreed with the consensus answers to six or fewer questions. Assigning the imaginary nodules to categories higher than the consensus answer was more frequent (16.0%) than assigning them to lower categories (5.5%), and the agreement rate was below 50% for two scenarios. CONCLUSION: When given difficult-to-classify scenarios, chest radiologists showed large variability in their interpretations of the Lung-RADS categories, with high frequencies of disagreement in some specific scenarios.

Depth of Pleural Effusion in Thoracentesis: Comparison of Lateral, Posterolateral and Posterior Approaches in the Supine Position.

BACKGROUND: In patients who have difficulty sitting, thoracentesis is attempted in a supine position via lateral approach. Recently, a new table has been designed for supine thoracentesis. This table has gaps that allow access to the posterolateral and posterior hemithorax. OBJECTIVES: To compare important safety-related parameters between lateral, posterolateral, and posterior approaches in supine thoracentesis. MATERIALS AND METHODS: First, two cadavers were placed supine on a table featuring gaps allowing access to the posterolateral and posterior hemithorax. Water was administered with sonographic measurement of the depth of pleural effusion (DPE) at the mid-axillary and posterior axillary line. Second, CT images were analyzed in 25 consecutive patients (32 free-shifting, moderate-to-large effusions; mean, 668 (146 - 2020 mL). DPE, craniocaudal distance that effusion can be visualized (CCD), and presence of passive atelectasis at each of the lateral, posterolateral, and posterior routes was assessed. RESULTS: In each cadaver, DPE in the posterolateral route was greater than that in the lateral route (P = 0.002, P < 0.001). The amount of pleural fluid enough to spread DPE to higher than 1 cm at the posterior axillary line was less than half the amount at the mid-axillary line (500 mL vs. 1,100 mL; 800 mL vs. 1700 mL). CT showed that the DPEs and CCDs of posterolateral and posterior routes were greater than those of the lateral route (P < 0.001). In thirteen effusions (40.6%), DPE was greater than 1 cm in both posterolateral and posterior routes but less than 1 cm in the lateral route. Frequencies of passive atelectasis in posterolateral and posterior routes (81.3% and 90.6%) were higher (P < 0.001) than that in the lateral route (28.1%). CONCLUSION: Safety-related parameters of posterolateral and posterior approaches in supine thoracentesis are far better than that of the conventional lateral approach.

First reported case of interferon-alpha-induced sarcoidosis in an Asian patient with malignant melanoma.

Anticancer agents can induce sarcoidosis. Interferon-alpha, which is used for the treatment of malignant melanoma and renal cell cancer, is one causative agent of sarcoidosis. However, there are few reports of interferon-alpha-induced sarcoidosis in patients with malignant melanoma. Clinically, it is important to consider the possibility of sarcoidosis in such patients because it could be easily regarded as a metastatic lesion due to underlying malignancy and given unnecessary treatment. Here, we report on the first case of interferon-alpha-induced sarcoidosis in an Asian melanoma patient.

Clinical experience of spontaneous pneumomediastinum: diagnosis and treatment.

BACKGROUND: Spontaneous pneumomediastinum (SPM) is a benign disease with a variety degree of severity but definite treatment modality is not clearly identified with its rarity. The purpose of this study was to review our experience and discuss the management of SPM according to the severity of disease. METHODS: From March 1996 to December 2012, total 64 patients were enrolled and classified as mild, moderate and severe groups and subsequent clinical courses were analyzed retrospectively. RESULTS: Fifty-one were males and 13 were females (M:F =3.9:1) with a mean age of 18 years old (range: 10-30 years old). Thirty-six patients were in mild, 22 in moderate and 6 in severe group. Chief complaints were chest pain (50 cases; 78.1%), neck pain (35 cases; 54.7%), dyspnea (18 cases; 28.1%), odynophagia (9 cases; 14.1%) and precipitating factors were coughing in 12 cases, feeding problems in 9 cases, and vomiting in 7 cases; however, 34 patients (53.1%) had no precipitating signs. All patients received oxygen therapy (100%), prophylactic antibiotics in 57 patients (89.1%), and pain medications in 47 patients (73.4%). The mean hospital stay was 4.6 days (range: 1-10 days). There was an increased linear trend according to time to visit (P=0.023) but clinical course demonstrated no significant trend between groups. CONCLUSIONS: These data demonstrated that there was no difference in symptom, clinical course and SPM was adequately treated with conservative management regardless of the degree of severity of SPM.

Axillary arch: detailed ultrasonographic images with multiplanar CT correlation.

The axillary arch is a common but rarely recognized anatomical variant of the axillary musculature. We report the first detailed presentation of the ultrasonographic features of the axillary arch and a correlation of these findings with multiplanar reformation CT images incorporating a schematic anatomical diagram in a 44-year-old woman complaining of a palpable non-tender mass in the axillary region due to a unilateral axillary arch. The clinical significance of the axillary arch is discussed.

Endobronchial angiofibroma in the aberrant tracheal bronchus presenting as spontaneous pneumomediastinum.

BACKGROUND: Spontaneous pneumomediastinum is a self-limiting benign disease but abnormal bronchial lesions can be rarely found incidentally, and in selected cases will require surgical resection. MATERIALS AND METHODS: A 38-year-old man presented with a spontaneous pneumomediastinum. Chest computed tomography revealed an incidental linear endobronchial tumour in the aberrant tracheal bronchus. The tumour was removed surgically and diagnosed with a rare benign tumour of endobronchial angiofibroma. CONCLUSIONS: We report a rare case of endobronchial angiofibroma in the aberrant tracheal bronchus which was detected during the evaluation of a spontaneous pneumomediastinum.

Arteria praebronchialis found on MDCT: potentially dangerous aberrant artery supplying the left lower lobe.

PURPOSE: To describe the incidence and CT features of a rare branching pattern of the pulmonary artery, the Arteria praebronchialis (AP): According to the initial description, the AP originates as the first branch of the left pulmonary artery, crosses the front of the left mainstem bronchus and then runs along the mediastinal margin as it gives off branches to one or more of the basal segments. MATERIALS AND METHODS: Since the incidental discovery of the first patient, contrast-enhanced CT was screened by one radiologist for the presence of AP, until three more cases were identified. In those four patients, segmental and lobar branching patterns of the AP were assessed. RESULTS: The estimated incidence of the AP was 0.03%. All four patients were men. Compared to the normal interlobar artery, the AP was smaller (n = 2), larger (n = 1), or of an equal size (n = 1). The segmental branches of the AP to the upper lobe (present in three patients) were A3 and A4 (n = 1), A3 and A5 (n = 1) and A4+5 (n = 1), respectively. Regarding the supply of the left lower lobe, AP gave off A7+8 and A9 (n = 2), A7+8 (n = 1), and A7 and A10 (n = 1), respectively. In two patients, a contralateral variant of pulmonary arterial branching was found, with (right) A7 arising as the first branch of right pulmonary artery. CONCLUSION: The AP is extremely rare, but has a strong male predilection and highly diverse branching patterns in both the current study and the literature. Radiologists should familiarize themselves with the CT features of this surgically important variation, and be able to describe its lobar and segmental blood supply.

Acute pulmonary complications in patients with hematologic malignancies.

Various acute pulmonary complications may occur in patients with hematologic malignancies because they are in an immunocompromised state due to systemic disease or to chemotherapy or hematopoietic stem cell transplantation. Pulmonary complications may arise from other treatment regimens, as well, or from direct pulmonary involvement in the malignant disease process. The differential diagnosis of pulmonary opacities in patients with hematologic malignancies is broad and includes both infectious and noninfectious causes. Pulmonary hemorrhage, edema, leukostasis, and pneumonia are well-known and common acute pulmonary complications. Less common complications are now encountered with increasing frequency because of the increasing complexity of therapeutic regimens for hematologic malignancies, which may include various drugs that are in clinical trials or were recently released to market. These once uncommon acute pulmonary complications include retinoic acid syndrome, tyrosine kinase inhibitor-induced pulmonary complications, engraftment syndrome, and hemophagocytic lymphohistiocytosis. It is often difficult to differentiate between these entities. However, the clinical setting and radiologic imaging findings may provide clues for interpreting imaging findings of abnormal pulmonary opacity in patients with a hematologic malignancy. Pulmonary hemorrhage is characterized by a sudden onset of symptoms and rapid progression of pulmonary imaging abnormalities and usually occurs in patients with impaired coagulation or a predisposition to bleed. Pulmonary edema should be considered when typical findings of hydrostatic pulmonary edema are seen. Pulmonary leukostasis develops in patients with hyperleukocytosis and leads to symptoms such as a cough, fever, and dyspnea. Various types of pneumonia may develop, depending on the degree and duration of immunosuppression in the patient. Retinoic acid syndrome, tyrosine kinase inhibitor-induced pulmonary complications, and engraftment syndrome occur after specific treatments, so a detailed medical history including recent or current treatments may be helpful for diagnosis. Accurate differentiation of these entities allows their appropriate management, with resultant decreases in morbidity and mortality.

Novel supine thoracentesis bed enabling thoracentesis via the posterior axillary line.

PURPOSE: This study describes on supine thoracentesis bed (STB), which helps thoracentesis of supine patient by enabling unlimited access to the posterolateral surface of a hemithorax. MATERIALS AND METHODS: Records of 15 patients who had received US-guided supine thoracentesis on STB were reviewed. We investigated the lateral or posterolateral approaches selected by the operators. We reviewed pre-procedural CT scans (obtained within 1 day) to examine if the approach of the operators could be justified in terms of depth of effusion and overlying chest wall thickness. RESULTS: The most common rationale for the use of the supine position was back or leg pain in 6 patients and hemi-or quadriplegia in 4. The operators chose the posterolateral approach in all 15 patients. On 6 concurrent CT scans, the mean depth of effusion was significantly (p < 0.004) greater in the posterolateral approach (3.0 ± 2.2 vs. 1.5 ± 1.9 cm). There was no significant difference in the thickness of the chest wall between the two approaches (1.6 ± 0.3 vs. 1.8 ± 1.0 cm, p = 0.61). CONCLUSIONS: By using STB, supine thoracentesis can be done via the posterolateral approach, which was associated with greater depth of effusion in our study, and may be superior to the conventional lateral approach.

Solitary fibrous tumor of the pleura manifesting as an air-containing cystic mass: radiologic and histopathologic correlation.

Solitary fibrous tumor (SFT) is a rare mesenchymal neoplasm that typically presents as a well-defined lobular soft tissue mass commonly arising from the pleura. We report an extremely rare case of an SFT containing air arising from the right major fissure in a 58-year-old woman. Chest CT showed an ovoid air-containing cystic mass with an internal, homogeneously enhancing solid nodule. To our knowledge, this is the first case in the literature. The histopathologic findings were correlated with the radiologic findings, and the mechanism of air retention within the tumor is discussed.

Complications of pneumoconiosis: radiologic overview.

A wide spectrum of pulmonary complications occurs in patients with pneumoconiosis. Those complications include chronic obstructive pulmonary disease, hemoptysis, pneumothorax, pleural disease, tuberculosis, autoimmune disease, anthracofibrosis, chronic interstitial pneumonia, and malignancy. Generally, imaging workup starts with plain chest radiography. However, sometimes, plain radiography has limited role in the diagnosis of pulmonary complications of pneumoconiosis because of overlapping pneumoconiotic infiltration. Computed tomography (CT), ultrasonography (US), and magnetic resonance imaging (MRI) are potentially helpful for the detection of pulmonary complications in patients with pneumoconiosis. CT, with its excellent contrast resolution, is more sensitive and specific method than plain radiograph in the evaluation of pulmonary abnormalities. CT is useful in detecting lung parenchymal abnormalities caused by infection, anthracofibrosis, and chronic interstitial pneumonia. Also, CT is valuable in distinguishing localized pneumothorax from bullae and aiding the identification of multiloculated effusions. US can be used in detection of complicated pleural effusions and guidance of the thoracentesis procedure. MRI is useful for differentiating between progressive massive fibrosis and lung cancer. Radiologists need to be familiar with the radiologic and clinical manifestations of, as well as diagnostic approaches to, complications associated with pneumoconiosis. Knowledge of the various imaging features of pulmonary complications of pneumoconiosis can enhance early diagnosis and improve the chance to cure.

Multidetector row computed tomography quantification of bronchiolitis obliterans syndrome after hematopoietic stem cell transplantation: a pilot study.

PURPOSE: To evaluate multidetector row computed tomographic indexes to quantify bronchiolitis obliterans syndrome (BOS) after hematopoietic stem cell transplantation by correlation with pulmonary function tests (PFT). MATERIALS AND METHODS: Eighteen patients with BOS after hematopoietic stem cell transplantation and 18 age-matched healthy volunteers were included. They underwent multidetector row computed tomography including inspiration and expiration scans. The patients also underwent PFTs. Mean lung density (MLD), relative areas (RAs) of lung with attenuation coefficients below specific thresholds, and 9 percentiles of the distribution of attenuation coefficients were computed. These parameters and PFT results were correlated. RESULTS: Mean MLD on inspiration (MLDin), MLD on expiration (MLDex), and the difference between the 2 (ΔMLD) were -858.5 HU, -788.6 HU, and 69.9, respectively, for the patients and -815.9 HU, -691.8 HU, and 124.1, respectively, for the volunteers. These parameters showed significant differences between the 2 groups (P<0.001) and strongly correlated with patients' residual forced expiratory volume in 1 second (FEV1) (r=0.71, 0.92, and 0.85, P≤0.001, respectively). RA with attenuation coefficients <-800 HU (RA800e) and the 80th percentile (80the) on expiration correlated most highly with the patients' residual FEV1 (r=-0.94, P<0.001). CONCLUSIONS: RA with attenuation coefficients <-800 HU (RA800e) and the 80th percentile (80the) on expiration are valid indexes of the patients' residual FEV1 in BOS.

Multidetector computed tomography detection of absent right superior vena cava and persistent left superior vena cava in an adult.

We report a rare case of the absence of the right superior vena cava and a persistent left superior vena cava in a 46-year-old man. This congenital venous anomaly was incidentally found on low-dose chest computed tomography and was clearly demonstrated by 3-dimensional volume-rendering image of multidetector computed tomography. Prior to computed tomography scanning, the scan range, optimal contrast enhancement, and reconstruction methods should be carefully planned to obtain the best diagnostic image of the venous anomalies using multidetector computed tomography.

Dynamic CT and MRA findings of a case of portopulmonary venous anastomosis (PPVA) in a patient with portal hypertension: a case report and review of the literature.

Portopulmonary venous anastomosis (PPVA), which has been rarely reported in conventional CT and MR studies, is an unusual collateral pathway in patients with portal hypertension. It has clinical implications related to right-to-left shunt that are different from the clinical implications related to other more usual portosystemic shunts in portal hypertensive patients. Here, we report the dynamic CT and MRA findings of a case of PPVA in a patient with portal hypertension, directly demonstrating the shunt flow from the paraesophageal varix to the left atrium via the right inferior pulmonary vein.

MDCT abnormalities of small- and medium-sized bronchus in active tuberculosis: a new angle on an old disease.

BACKGROUND: The incidence and findings of tuberculous invasion of the peripheral bronchus have not been fully investigated with MDCT. Purpose To evaluate the prevalence and findings of MDCT abnormalities of small- and medium-sized bronchus (SMB) in active pulmonary tuberculosis (TB). MATERIAL AND METHODS: Using multiplanar reformation, 35 consecutive MDCT scans (follow-up exams available in 14 patients with a mean interval of 8.1 months) were assessed for following abnormalities of SMB: bronchial impaction (BI), wall thickening, dilatation, peribronchial cuff of soft tissue, and bronchocavitary fistula. It was also assessed whether tree-in-buds (TIB) have a tendency to distribute in the territories of diseased SMB, and whether SMB abnormalities are present in patients with relatively mild disease. RESULTS: SMB abnormalities were observed in 23 (65.7%) patients with active TB. The most frequent finding was wall thickening (n = 18, 51.4%), followed by BI (n = 13, 37.1%; zigzag-shaped in four), dilatation (n = 11, 31.4%), amputated appearance of air column (n = 11, 31.4%), peribronchial cuff of soft tissue (n = 10, 28.6%), and bronchocavitary fistula (n =8, 22.9%). TIB (n = 29; absent in two patients with SMB) was mainly within (n = 14) or close to (n = 4) the territory of diseased SMB. Follow-up CT frequently showed improvement of wall thickening (11/12) and persistence of bronchial dilatation (11/13). SMB abnormality was present in all of six patients with mild disease. CONCLUSION: MDCT shows that tuberculous invasion of the peripheral bronchus may be more frequent than previously thought, of which findings include wall thickening, BI, dilatation, amputated appearance of air column, peribronchial cuff of soft tissue and bronchocavitary fistula.