HighResolution Chest CT Practical Clinical Applications Paul L

High-Resolution Chest CT: Practical Clinical Applications Paul L. Molina, M. D. Department of Radiology University of North Carolina at Chapel Hill

Disclosures None

Objectives • Identify current clinical indications for the use of HRCT • Review proper technique for performance of HRCT • Summarize the characteristic patterns of abnormality seen on HRCT and the most common diseases resulting in their formation

HRCT - Indication • Evaluation of patients with suspected infiltrative lung disease but normal or nonspecific findings on CXR

HRCT - Indication • Further characterization of known or suspected diffuse lung disease

HRCT - Indication • Evaluation of patients in whom radiographic findings are not in keeping with clinical findings or pulmonary function tests

HRCT - Indication • Delineation of disease prior to lung biopsy as a guide to the optimal type and site of biopsy

HRCT Technique • Thin collimation (1 mm) • High spatial frequency reconstruction • Windows -700/1000 -1500 HU • • Prone scans – differentiate atelectasis Expiratory scans – air trapping

HRCT Findings • Septal thickening • Reticular densities • Nodules • Increased lung opacity • Decreased lung opacity

Septal Thickening • Pulmonary edema • Lymphangitic carcinomatosis • Sarcoidosis • Asbestosis • Idiopathic pulmonary fibrosis

Reticular Densities • Idiopathic pulmonary fibrosis • Collagen vascular disease • Asbestosis • Chronic hypersensitivity pneumonitis • Sarcoidosis

UIP

Nodular Opacities • Sarcoidosis • Silicosis • Coal worker’s pneumoconiosis • Hypersensitivity pneumonitis • Tuberculosis • Metastatic disease

Nodular Opacities • Perilymphatic nodules • Random distribution • Centrilobular nodules

Perilymphatic Nodules • Sarcoidosis • Silicosis • Lymphangitic Ca

Silicosis

Random Nodules • Miliary TB • Hematogenous mets m

Metastatic adenoca

Centrilobular Nodules • Endobronchial spread of TB or other infection • Hypersensitivity pneumonitis • Endobronchial tumor spread

Nodular Opacities • Perilymphatic nodules • Random distribution • Centrilobular nodules

Increased Lung Opacity • Ground-glass opacity • Air-space consolidation

Ground-glass Opacity • Hypersensitivity pneumonitis (subacute) • Desquamative interstitial pneumonitis • Non-specific interstitial pneumonitis • Sarcoidosis • Alveolar proteinosis

DIP

Non-specific Interstitial Pneumonitis

Crazy-Paving Alveolar Proteinosis

Mosaic Pefusion

Consolidation • Obscures underlying vessels • Solid, opaque • Air bronchograms

Consolidation • Chronic eosinophilic pneumonia • BOOP / COP • Bronchoalveolar cell carcinoma • Lymphoma

Chronic Eosinophilic Pneumonia

BOOP / COP

Decreased Lung Opacity • Emphysema • Cystic airspaces • Mosaic perfusion

Cystic Airspaces • Lymphangioleiomyomatosis (LAM) • Langerhans Cell Histiocytosis (EG) • End-stage (honeycomb) lung

LAM

EG

HRCT - Indications • Suspected infiltrative disease but normal or nonspecific CXR • Further characterize diffuse disease • CXR findings not in keeping with clinical findings or PFT’s • Guide type and site of biopsy

HRCT Findings • Septal thickening • Reticular opacities • Nodular opacities • Increased lung opacity • Decreased lung opacity