High-Resolution Chest CT: High-Resolution Chest CT: Practical Clinical ApplicationsPractical Clinical Applications

Paul L. Molina, M.D.Department of Radiology

University of North Carolina at Chapel Hill

DisclosuresDisclosures

NoneNone

ObjectivesObjectives

• Identify current clinical indications Identify current clinical indications for the use of HRCTfor the use of HRCT

• Review proper technique forReview proper technique for performance of HRCTperformance of HRCT

• Summarize the characteristic Summarize the characteristic patterns of abnormality seen on patterns of abnormality seen on HRCT and the most commonHRCT and the most common diseases resulting in their formationdiseases resulting in their formation

HRCT - IndicationHRCT - Indication

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

HRCT - IndicationHRCT - Indication

• Further characterization of Further characterization of known or suspected diffuse known or suspected diffuse lung diseaselung disease

HRCT - IndicationHRCT - Indication

• Evaluation of patients in whomEvaluation of patients in whom radiographic findings are not radiographic findings are not in keeping with clinical findings in keeping with clinical findings or pulmonary function testsor pulmonary function tests

HRCT - IndicationHRCT - Indication

• Delineation of disease prior toDelineation of disease prior to

lung biopsy as a guide to thelung biopsy as a guide to the

optimal type and site of biopsyoptimal type and site of biopsy

HRCT TechniqueHRCT Technique

• Thin collimation (1 mm)Thin collimation (1 mm) • High spatial frequency reconstructionHigh spatial frequency reconstruction

• Windows -700/1000-1500 HUWindows -700/1000-1500 HU • Prone scans – differentiate atelectasisProne scans – differentiate atelectasis• Expiratory scans – air trappingExpiratory scans – air trapping

HRCT Findings

• Septal thickeningSeptal thickening• Reticular densitiesReticular densities• NodulesNodules• Increased lung opacityIncreased lung opacity• Decreased lung opacityDecreased lung opacity

Septal ThickeningSeptal Thickening

• Pulmonary edemaPulmonary edema• Lymphangitic carcinomatosisLymphangitic carcinomatosis• SarcoidosisSarcoidosis• AsbestosisAsbestosis• Idiopathic pulmonary fibrosisIdiopathic pulmonary fibrosis

Reticular DensitiesReticular Densities

• Idiopathic pulmonary fibrosisIdiopathic pulmonary fibrosis• Collagen vascular diseaseCollagen vascular disease• AsbestosisAsbestosis• ChronicChronic hypersensitivity pneumonitishypersensitivity pneumonitis• SarcoidosisSarcoidosis

UIPUIP

Nodular OpacitiesNodular Opacities• SarcoidosisSarcoidosis• SilicosisSilicosis• Coal worker’s pneumoconiosisCoal worker’s pneumoconiosis• Hypersensitivity pneumonitisHypersensitivity pneumonitis• TuberculosisTuberculosis• Metastatic diseaseMetastatic disease

Nodular OpacitiesNodular Opacities

• Perilymphatic nodulesPerilymphatic nodules

• Random distributionRandom distribution

• Centrilobular nodulesCentrilobular nodules

Perilymphatic NodulesPerilymphatic Nodules

• SarcoidosisSarcoidosis

• SilicosisSilicosis

• Lymphangitic CaLymphangitic Ca

SilicosisSilicosis

Random NodulesRandom Nodules

• Miliary TBMiliary TB

• Hematogenous mHematogenous mets

Metastatic adenocaMetastatic adenoca

Centrilobular NodulesCentrilobular Nodules

• Endobronchial spread of TB Endobronchial spread of TB

or other infectionor other infection• Hypersensitivity pneumonitisHypersensitivity pneumonitis• Endobronchial tumor spreadEndobronchial tumor spread

Nodular OpacitiesNodular Opacities

• Perilymphatic nodulesPerilymphatic nodules

• Random distributionRandom distribution

• Centrilobular nodulesCentrilobular nodules

Increased Lung OpacityIncreased Lung Opacity

• Ground-glass opacityGround-glass opacity

• Air-space consolidationAir-space consolidation

Ground-glass OpacityGround-glass Opacity

• Hypersensitivity pneumonitis (subacute)Hypersensitivity pneumonitis (subacute)• Desquamative interstitial pneumonitis Desquamative interstitial pneumonitis • Non-specific interstitial pneumonitisNon-specific interstitial pneumonitis• SarcoidosisSarcoidosis• Alveolar proteinosisAlveolar proteinosis

DIPDIP

Non-specific Interstitial PneumonitisNon-specific Interstitial Pneumonitis

Crazy-PavingCrazy-Paving

Alveolar Alveolar ProteinosisProteinosis

Mosaic PefusionMosaic Pefusion

ConsolidationConsolidation

• Obscures underlying vesselsObscures underlying vessels• Solid, opaqueSolid, opaque• Air bronchogramsAir bronchograms

ConsolidationConsolidation

• Chronic eosinophilic pneumoniaChronic eosinophilic pneumonia• BOOP / COPBOOP / COP• Bronchoalveolar cell carcinomaBronchoalveolar cell carcinoma• LymphomaLymphoma

Chronic Eosinophilic PneumoniaChronic Eosinophilic Pneumonia

BOOP / COPBOOP / COP

Decreased Lung OpacityDecreased Lung Opacity

• EmphysemaEmphysema• Cystic airspacesCystic airspaces• Mosaic perfusionMosaic perfusion

Cystic AirspacesCystic Airspaces

• Lymphangioleiomyomatosis (LAM)Lymphangioleiomyomatosis (LAM)

• Langerhans Cell Histiocytosis (EG)Langerhans Cell Histiocytosis (EG)

• End-stage (honeycomb) lung End-stage (honeycomb) lung

LAMLAM

EGEG

HRCT - IndicationsHRCT - Indications

• Suspected infiltrative disease but Suspected infiltrative disease but normal or nonspecific CXRnormal or nonspecific CXR

• Further characterize diffuse diseaseFurther characterize diffuse disease

• CXR findings not in keeping with CXR findings not in keeping with clinical findings or PFT’sclinical findings or PFT’s

• Guide type and site of biopsyGuide type and site of biopsy

HRCT FindingsHRCT Findings

• Septal thickeningSeptal thickening• Reticular opacitiesReticular opacities• Nodular opacitiesNodular opacities• Increased lung opacityIncreased lung opacity• Decreased lung opacityDecreased lung opacity