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
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