Diane C. Strollo

High-Resolution CT Scan Findings in Patients With Symptomatic Scleroderma-Related Interstitial Lung Disease

BACKGROUND Lung disease has become the leading cause of mortality and morbidity in scleroderma (SSc) patients. The frequency, nature, and progression of interstitial lung disease seen on high-resolution CT (HRCT) scans in patients with diffuse SSc (dcSSc) compared with those with limited SSc (lcSSc) has not been well characterized. METHODS Baseline HRCT scan images of 162 participants randomized into a National Institutes of Health-funded clinical trial were compared to clinical features, pulmonary function test measures, and BAL fluid cellularity. The extent and distribution of interstitial lung disease HRCT findings, including pure ground-glass opacity (pGGO), pulmonary fibrosis (PF), and honeycomb cysts (HCs), were recorded in the upper, middle, and lower lung zones on baseline and follow-up CT scan studies. RESULTS HRCT scan findings included 92.9% PF, 49.4% pGGO, and 37.2% HCs. There was a significantly higher incidence of HCs in the three zones in lcSSc patients compared to dcSSc patients (p = 0.034, p = 0.048, and p = 0.0007, respectively). The extent of PF seen on HRCT scans was significantly negatively correlated with FVC (r = - 0.22), diffusing capacity of the lung for carbon monoxide (r = - 0.44), and total lung capacity (r = - 0.36). A positive correlation was found between pGGO and the increased number of acute inflammatory cells found in BAL fluid (r = 0.28). In the placebo group, disease progression was assessed as 30% in the upper and middle lung zones, and 45% in the lower lung zones. No difference in the progression rate was seen between lcSSc and dcSSc patients. CONCLUSIONS PF and GGO were the most common HRCT scan findings in symptomatic SSc patients. HCs were seen in more than one third of cases, being more common in lcSSc vs dcSSc. There was no relationship between progression and baseline PF extent or lcSSc vs dcSSc. TRIAL REGISTRATION Clinicaltrials.gov Identifier: NCT00004563.

Non-cardiac findings on coronary electron beam computed tomography scanning.

The objective of this study was to estimate the prevalence and significance of non-cardiac findings on Electron Beam Computed Tomography (EBT) scanning when used in population screening for the quantitative measurement of coronary artery calcium and estimate of coronary risk. Clinic files of 1366 subjects who underwent EBT scanning between September 1996 and December 1998 at the University of Pittsburgh affiliated Comprehensive Heart Care Center were abstracted. The files of 1356 subjects contained the calcium score and non-cardiac findings as reported by board-certified radiologists, who interpreted the scans during the period 1996–1998. A National Death Index (NDI) Plus match was performed to ascertain cause of death. Two hundred seventy-eight of 1356 (20.5%) subjects had 1 or more non-cardiac findings on EBT scanning. Fifty-seven of 1356 (4.2%) received a recommendation for diagnostic CT follow-up. Forty-six of the 57 recommendations were for pulmonary nodules and 11 were for non-nodule, non-cardiac findings. Seven members of the cohort died during a short follow-up period. In 1 case, the non-cardiac finding was the cause of death. Non-cardiac findings in a healthy cohort referred for EBT coronary screening are relatively common. Findings range from clinically insignificant to the cause of death during a short follow-up period. EBT scanning is a frequently used coronary screening procedure. With the relatively high detection of significant, non-cardiac pathology in this increasingly common screening procedure, consideration should be given for radiologists to interpret the scans.

Treatment of Scleroderma-Interstitial Lung Disease With Cyclophosphamide Is Associated With Less Progressive Fibrosis on Serial Thoracic High-Resolution CT Scan Than Placebo: Findings From the Scleroderma Lung Study

BACKGROUND The Scleroderma Lung Study (SLS) demonstrated significant treatment-associated improvements in pulmonary function and symptoms when patients with scleroderma-related interstitial lung disease (SSc-ILD) were treated with a 1-year course of cyclophosphamide (CYC) in a randomized, double-blinded, placebo-controlled clinical trial. This study examined thoracic high-resolution CT (HRCT) scans obtained during the SLS for treatment-associated changes over time. METHODS Ninety-eight of the 158 subjects (CYC group, 49 subjects; placebo group, 49 subjects) participating in the SLS underwent thoracic HRCT scans both at baseline and after 12 months of treatment, which were available for analysis. Two independent radiologists visually scored the baseline HRCT scans for the presence of ground-glass opacities (GGOs), fibrosis (FIB), and honeycomb cysts (HCs) on a scale of 0 to 4. The treatment effect at 12 months was assessed by a blinded comparison of baseline and follow-up scans for evidence of stability and improvement (not worse) or deterioration (worse). RESULTS At the end of treatment, FIB was significantly worse in the placebo treatment group than in the CYC treatment group (p = 0.014). Furthermore, differences in the 12-month change in FIB between the CYC and placebo groups correlated significantly with other outcome measures, including the 12-month changes in FVC (p < 0.05), total lung capacity (p < 0.05), and dyspnea (p < 0.001) scores. However, no differences were noted between the two groups with respect to changes in either GGOs or HCs. CONCLUSIONS A 1-year course of treatment of SSc-ILD with CYC was associated with treatment-related changes in FIB scores on HRCT scans, which correlated with other measures of treatment response. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT00004563.

Tumors of the Thymus

Thymic neoplasms are a common cause of an anterior mediastinal mass and may be benign or malignant. Thymic cysts are congenital or acquired and may be associated with a thymic malignancy. True thymic hyperplasia and thymic lymphoid hyperplasia may enlarge the thymus and simulate a neoplasm. Thymoma and thymic carcinoma are epithelial malignancies with distinct clinicopathologic features. Thymic carcinoid is a rare aggressive neuroendocrine malignancy associated with multiple endocrine neoplasia 1. Thymolipoma is a benign neoplasm. Hodgkin and non-Hodgkin lymphoma may primarily or secondarily involve the thymus. Primary mediastinal germ cell tumors may arise primarily within the thymus and include mature teratoma, seminoma, and non-seminomatous malignant germ cell tumors.

Imaging of Thymic Epithelial Neoplasms

Thymic epithelial neoplasms are uncommon lesions. Affected patients may be asymptomatic or may present with thoracic complaints or paraneoplastic syndromes. Asymptomatic lesions may be discovered incidentally during chest radiography or during other chest imaging studies. This article addresses the imaging evaluation of patients who have thymic epithelial neoplasms, specifically covering the use of chest radiography, CT, MRI, and positron emission tomography.

Imaging Lung Disease in Systemic Sclerosis

Interstitial lung disease and pulmonary hypertension (PH) are the most common cardiopulmonary findings in patients with systemic sclerosis (SSc). About two thirds of patients suffering from SSc develop scleroderma interstitial lung disease. PH is present in about 20% of SSc patients and is typically associated with severe lung disease, although it may be an isolated manifestation of SSc. High-resolution CT scanning is a key method for evaluating chest involvement. There are four roles of imaging in scleroderma interstitial lung disease: 1) detection of lung involvement, 2) identification of patients likely to respond to treatment, 3) assessment of treatment efficacy, and 4) exclusion of other significant diseases to include PH and cardiac and esophageal abnormalities.

Primary mediastinal malignant germ cell neoplasms: imaging features

Mature teratomas are the most frequent primary mediastinal GCN. These are spherical multilocular cystic masses with thin, soft tissue septa and frequent internal fat attenuation. Primary mediastinal malignant GCNs are rare and should be included in the differential diagnosis of anterior mediastinal masses in young adult males. Seminomas are typically homogeneous masses indistinguishable from lymphomas. Radiologically nonseminomatous malignant germ cell neoplasms are large, locally invasive heterogeneous masses with central low-attenuation and frond-like peripheral soft tissue. Gonadal primary malignancy and intervening abdominal lymph node involvement should be excluded. Tumor markers play a crucial role in the initial evaluation of anterior mediastinal masses in these patients and in evaluating response to therapy and possible recurrence. Follow-up imaging is helpful in detection and characterization of residual neoplasm.

Imaging of the Normal Trachea

Trachea; evaluation is a fundamental part of chest imaging. Adult tracheal anatomy is well understood, but tracheal embryology is not. There have been major advances in imaging, but radiography remains the initial imaging study for most tracheal pathology. Careful radiographic analysis can yield considerable information.

Amyloidosis: Modern Cross-sectional Imaging

Amyloidosis is a rare diverse condition caused by the pathologic extracellular deposition of abnormal insoluble proteins throughout the body. It may exist as a primary disease or, more commonly, may be secondary to a wide variety of pathologic processes ranging from chronic infection or inflammation to malignancy. Hereditary forms also exist. On the basis of the structure of the protein deposits, more than two dozen subtypes of amyloidosis have been described. A single organ or multiple organ systems may be affected. The radiologic manifestations of amyloidosis are varied and often nonspecific, making amyloidosis a diagnostic challenge for the radiologist. In the chest, the lungs, mediastinum, pleura, and heart may be involved. Lung involvement may manifest as diffuse reticulonodular interstitial thickening, consolidations, or solitary or multiple parenchymal nodules that may calcify, cavitate, and slowly enlarge. Pleural involvement most commonly manifests as pleural effusions. Tracheobronchial involvement may exhibit concentric airway thickening, mural and intraluminal nodules, submucosal calcification, and airway obstruction. Mediastinal and hilar lymph nodes may enlarge and frequently calcify. At cardiac magnetic resonance (MR) imaging, the left ventricular wall is typically thickened, with associated diastolic dysfunction. Delayed contrast material-enhanced cardiac MR imaging typically shows global transmural or subendocardial enhancement. The pathophysiology, classification, treatment, and prognosis of amyloidosis are reviewed, followed by case examples of the appearance of thoracic and cardiac amyloidosis on chest radiographs, computed tomographic (CT) images, and cardiac MR images.

CT Quality Assurance in the Lung Screening Study Component of the National Lung Screening Trial: Implications for Multicenter Imaging Trials

OBJECTIVE The purpose of this study was to describe the effect of implementing an imaging quality assurance program on CT image quality in the Lung Screening Study component of the National Lung Screening Trial. MATERIALS AND METHODS The National Lung Screening Trial is a multicenter study in which 53,457 subjects at increased risk of lung cancer were randomized to undergo three annual chest CT or radiographic screenings for lung cancer to determine the relative effect of use of the two screening tests on lung cancer mortality. Of the 26,724 subjects randomized to the CT screening arm of the National Lung Screening Trial, the Lung Screening Study randomized 17,309 through 10 screening centers. The others were randomized through the American College of Radiology Imaging Network. Quality assurance procedures were implemented that included centralized review of a random sample of 1,504 Lung Screening Study CT examinations. Quality defect rates were tabulated. RESULTS Quality defect rates ranged from 0% (section reconstruction interval) to 7.1% (reconstructed field of view), and most errors were sporadic. However, a recurrently high effective tube current-time product setting at one center, excessive streak artifact at one center, and excessive section thickness at one center were detected and corrected through the quality assurance process. Field-of-view and scan length errors were less frequent over the second half of the screening period (p < 0.01 for both parameters, two-tailed, paired Students t test). Error rates varied among the screening centers and reviewers for most parameters evaluated. CONCLUSION Our experience suggested that centralized monitoring of image quality is helpful for reducing quality defects in multicenter trials.