HRCT in diagnosis of HRCT in diagnosis of diffuse Lung Diseasesdiffuse Lung Diseases

Dr/Ahmed BahnassyDr/Ahmed Bahnassy

Assistant Professor of Assistant Professor of RadiologyRadiology

Qassim UniversityQassim University

Technique and anatomyTechnique and anatomy

Very thin 1mm slices for chest with Very thin 1mm slices for chest with 10-20 mm intervals aiming at 10-20 mm intervals aiming at visualizing the lung interstitium. visualizing the lung interstitium.

Road map to diagnosisRoad map to diagnosis

1.1. Recognize the abnormality pattern.Recognize the abnormality pattern.

2.2. Locate it in relation to the lung and Locate it in relation to the lung and to the SPLto the SPL

3.3. Evaluate its effects on lung Evaluate its effects on lung parenchymaparenchyma

HRCT patternsHRCT patterns

Reticular patternReticular pattern Nodular pattern.Nodular pattern. Increased lung opacity.Increased lung opacity. Decreased lung opacity and cystic Decreased lung opacity and cystic

changeschanges

I-Reticular opacitiesI-Reticular opacities

Interlobular septal Interlobular septal thickening:thickening:

Causes :Causes :

1.1. Lymphangitic spread of Lymphangitic spread of tumour (asymmetrical or tumour (asymmetrical or symmetrical)symmetrical)

2.2. Pulmonary edema.Pulmonary edema.

3.3. AmyloidosisAmyloidosis

HoneycombingHoneycombing– CausesCauses::

1.1. IPFIPF2.2. Collagen vascular Collagen vascular

diseases (Rh.A. - diseases (Rh.A. - scleroderma)scleroderma)

3.3. Drug related fibrosisDrug related fibrosis4.4. End stage End stage

Hypersensitivity Hypersensitivity pneumonitispneumonitis

5.5. End Stage SarcoidosisEnd Stage Sarcoidosis6.6. Radiation.Radiation.7.7. End stage ARDSEnd stage ARDS

Traction BronchiectasisTraction Bronchiectasis

Causes :Causes :1.1. Non specific Non specific

intersitial intersitial pneumonia.pneumonia.

2.2. UIPUIP3.3. Sarcoidosis.Sarcoidosis.4.4. Hypersensitivity Hypersensitivity

pneumonitis.pneumonitis.5.5. Radiation.Radiation.6.6. End stage ARDSEnd stage ARDS

Corkscrewed Corkscrewed bronchi in IPFbronchi in IPF

I :Lymphangitic spread of I :Lymphangitic spread of tumourtumour

II-SclerodermaII-Scleroderma

III-IPFIII-IPF

Posterior lung cystsPosterior lung cysts Prone scanProne scan

IV-Rheumatoid arthritis-Dilated IV-Rheumatoid arthritis-Dilated bronchi=fibrosisbronchi=fibrosis

II-Nodules II-Nodules

Perilymphatic.Perilymphatic. Centrilobular.Centrilobular. RandomRandom

A-Perilymphatic nodulesA-Perilymphatic nodules

Causes :Causes :1.1. Sarcoidosis.Sarcoidosis.2.2. Silicosis.Silicosis.3.3. Lymphangitic Lymphangitic

spread of tumour.spread of tumour.4.4. Amyloidosis.Amyloidosis.5.5. Lymphocytic Lymphocytic

interstitialinterstitial pneumonitispneumonitis

I -SarcoidosisI -Sarcoidosis

II-Lymphangitis II-Lymphangitis carcinomatosiscarcinomatosis

B-Random nodulesB-Random nodules

causes :causes :

1.1. Miliary infectionMiliary infection

2.2. HaematogenouHaematogenous metastasis.s metastasis.

3.3. Sarcoidosis Sarcoidosis

I-Miliary TBI-Miliary TB

II-Miliary metsII-Miliary mets

C-Centrilobular nodules C-Centrilobular nodules causes :causes :1.1. Endobronchial spread of Endobronchial spread of

infection (Bacteria, virus, TB, infection (Bacteria, virus, TB, mycobacterium, fungus)mycobacterium, fungus)

2.2. Endobronchial spread of Endobronchial spread of tumor (BAC)tumor (BAC)

3.3. Hypersensitivity pneumonitis.Hypersensitivity pneumonitis.4.4. BOOPBOOP5.5. Silicosis and coal miner Silicosis and coal miner

pneumoconiosis pneumoconiosis

Centrilobular nodulesCentrilobular nodulesI-BronchopneumoniaI-Bronchopneumonia

II-Hypersensitivity II-Hypersensitivity pneumonitispneumonitis

Tree – in – bud appearance Tree – in – bud appearance

Causes :Causes :

1.1. Endobronchial spread of Endobronchial spread of infection(bacteria,TB ,fungi)infection(bacteria,TB ,fungi)

2.2. Airway disease with Airway disease with infection(CF ,bronchiectasisinfection(CF ,bronchiectasis))

3.3. Mucous Mucous plugging(asthma ,ABPA)plugging(asthma ,ABPA)

4.4. BAC .BAC .

I-Cystic fibrosis I-Cystic fibrosis

II-Air way infectionII-Air way infection

III-Pseudomonas III-Pseudomonas bronchopneumoniabronchopneumonia

III-Increased lung opacityIII-Increased lung opacity

Consolidation.Consolidation. Ground Glass opacification Ground Glass opacification

Consolidation causes. Consolidation causes.

Acute Symptoms:Acute Symptoms:– PneumoniaPneumonia– Pulmonary Pulmonary

edema,He.edema,He.– ARDSARDS

Chronic Chronic Symptoms :Symptoms :– Chronic eosinophilic Chronic eosinophilic

pneumoniapneumonia– BOOPBOOP– Interstitial Interstitial

pneumoniapneumonia– Lipoid pneumonia.Lipoid pneumonia.– BACBAC

Consolidation-I-Chronic Consolidation-I-Chronic eosinophilic pneumonia: eosinophilic pneumonia:

multifocal,patchy subpleural multifocal,patchy subpleural areas of consolidationareas of consolidation

II-BOOP:patchy GG opacity in II-BOOP:patchy GG opacity in peribronchial distribution. (Here peribronchial distribution. (Here post transplant graft versus host post transplant graft versus host

disease)disease)

Ground Glass Opacity Ground Glass Opacity causescauses

Acute Symptoms :Acute Symptoms :– Pulmonary edema, Pulmonary edema,

He.He.– Pneumonia.Pneumonia.– DADDAD– AIPAIP– Acute Acute

Hypersensitivity Hypersensitivity pneumonitis.pneumonitis.

Chronic Symptoms :Chronic Symptoms :– NSIPNSIP– UIPUIP– DIPDIP– Hypersensitivity Hypersensitivity

pneumonitis.pneumonitis.– Alveolar proteinosis.Alveolar proteinosis.– Sarcoidosis.Sarcoidosis.– Lipoid pneumonia.Lipoid pneumonia.– BACBAC

I-Pulmonary edemaI-Pulmonary edema

II-CMV infection:GG opacities II-CMV infection:GG opacities with centrilobular noduleswith centrilobular nodules

III-Pneumocystis carinii III-Pneumocystis carinii infectioninfection

IV-Hypersensitivity IV-Hypersensitivity pneumonitispneumonitis

Crazy-paving patternCrazy-paving pattern Combination of GG Combination of GG

opacity with interlobular opacity with interlobular septal thickening.septal thickening.

Non specific.Non specific. Causes Causes :: PCP , viral PCP , viral

pneumonia ,edema , pneumonia ,edema , hemorrhage ,ARDS .hemorrhage ,ARDS .

If chronic lung disease it If chronic lung disease it is often :alveolar is often :alveolar proteinosis proteinosis

Alveolar ProteinosisAlveolar Proteinosis

Fine reticular pattern + GG opacityFine reticular pattern + GG opacity

IV-Decreased lung opacity and IV-Decreased lung opacity and cystic lesions .cystic lesions .

1.1. Emphysema Emphysema (centrilobular ,(centrilobular ,panlobular ,parpanlobular ,paraseptal )aseptal )

2.2. Mosaic Mosaic perfusion.perfusion.

3.3. Air trapping .Air trapping .

4.4. Lung cysts .Lung cysts .

I-Centrilobular EmphysemaI-Centrilobular Emphysema

II-Panlobular EmphysemaII-Panlobular Emphysema

III-Paraseptal Emphysema III-Paraseptal Emphysema

Lung cysts –causes Lung cysts –causes

Common Common causes :causes :– BullaeBullae– Honeycombing.Honeycombing.– PneumatocekesPneumatocekes

..– Cystic Cystic

bronchiectasis.bronchiectasis.– Cysts in Cysts in

hypersensitivty hypersensitivty pneumonitispneumonitis

Uncommon:Uncommon: LymphangioleiomyLymphangioleiomy

omatosis.omatosis. LCHLCH TSTS Sjogren syndrome.Sjogren syndrome. LIPLIP PapillomatosisPapillomatosis

I-Lymphangiomyomatosis I-Lymphangiomyomatosis

II-LCHII-LCH

Mosaic appearanceMosaic appearance causes :causes : Airway Disease:Airway Disease:

– Large air way Large air way (CF ,Bronchiectasis)(CF ,Bronchiectasis)

– Small air way Small air way (BOOP ,small air (BOOP ,small air way way infection ,mucous infection ,mucous plugging)plugging)

Vascular diseases :Vascular diseases :– Chronic PEChronic PE– vasculitisvasculitis

Common Interstitial Common Interstitial lung diseaseslung diseases

UIP/IPFUIP/IPF

Reticular opacities, traction Reticular opacities, traction bronchiectasis + HCbronchiectasis + HC

NSIP=GG opacities NSIP=GG opacities +reticulations +reticulations

COP- Peribronchial COP- Peribronchial consolidations-GG opacity consolidations-GG opacity

COP=Irregular nodular COP=Irregular nodular opacities opacities

DIPDIP

LIPLIP

Golden rules for HRCT Golden rules for HRCT interpretation. interpretation.

Honeycombing with a basal and subpleural Honeycombing with a basal and subpleural redominance is highly suggestive of UIP.Lung biopsy redominance is highly suggestive of UIP.Lung biopsy is rarely performed when HRCT shows these findings.is rarely performed when HRCT shows these findings.

Concentric lower lobe GG opaity without Concentric lower lobe GG opaity without honeycombing suggests NSIP.In a patient with honeycombing suggests NSIP.In a patient with collagen vascular disease ,biopsy is uncommoly collagen vascular disease ,biopsy is uncommoly performed.performed.

Patchy or noular subpleural or peribronchial Patchy or noular subpleural or peribronchial consolidation is typical of COP.consolidation is typical of COP.

Cystic air spaces or GG opacity may represent LIP.LIP Cystic air spaces or GG opacity may represent LIP.LIP is usually associated with other diseases.is usually associated with other diseases.

Diffuse or centrilobular GG opacity in a smoker is Diffuse or centrilobular GG opacity in a smoker is typical of DIP or RB-ILDtypical of DIP or RB-ILD

ReferencesReferences 1 - HOGG JH. Chronic interstitial lung disease of unknown cause: a new classification 1 - HOGG JH. Chronic interstitial lung disease of unknown cause: a new classification

based on pathogenesis. A J R 1991; 156: 225-233. based on pathogenesis. A J R 1991; 156: 225-233. 2 - BERGIN C, ROGGLI V, COBLENTZ C, CHILES C. The secondary pulmonary lobule: 2 - BERGIN C, ROGGLI V, COBLENTZ C, CHILES C. The secondary pulmonary lobule:

normal and abnormal CT appearances. AJR 1988; 151:21-25. normal and abnormal CT appearances. AJR 1988; 151:21-25. 3 - WEBB WR, STEIN MG, FINKBEINER WE,JUNG GI I et coll. Normal and diseased 3 - WEBB WR, STEIN MG, FINKBEINER WE,JUNG GI I et coll. Normal and diseased

isolated lungs: high-resolution CT. Radiology 1988; 166: 81-87. isolated lungs: high-resolution CT. Radiology 1988; 166: 81-87. 4 - MURATA K, ITOH H, TODO G, KANAOKA M, NOMA S et coll. Centrilobular lesions of 4 - MURATA K, ITOH H, TODO G, KANAOKA M, NOMA S et coll. Centrilobular lesions of

the lungs: demonstration by high-resolution CT and pathologic correlation. Radiology the lungs: demonstration by high-resolution CT and pathologic correlation. Radiology 1986; 161: 641-645. 1986; 161: 641-645.

5 - REMY-JARDIN M, REMY J, GIRAUD F, WATTINNE L, GOSSELIN B. Computed 5 - REMY-JARDIN M, REMY J, GIRAUD F, WATTINNE L, GOSSELIN B. Computed tomography assessment of ground glass opacity : Semiology and significance. J tomography assessment of ground glass opacity : Semiology and significance. J Thorac Imaging 1993; 8 : 249-264. Thorac Imaging 1993; 8 : 249-264.

6 - BRAUNER MW, GRENIER Ph, MOMPOINT D, LENOIR S, De CREMOUX H. Pulmonary 6 - BRAUNER MW, GRENIER Ph, MOMPOINT D, LENOIR S, De CREMOUX H. Pulmonary sarcoidosis: evaluation with high-resolution CT. Radiology 1989; 172: 467-471. sarcoidosis: evaluation with high-resolution CT. Radiology 1989; 172: 467-471.

7 - MULLER NL, MILLER RR, WEBB WR, EWANS KG, OSTROW DN. Fibrosing alveolitis: 7 - MULLER NL, MILLER RR, WEBB WR, EWANS KG, OSTROW DN. Fibrosing alveolitis: Pathologic-CT correlation. Radiology 1986; 160: 585-588. Pathologic-CT correlation. Radiology 1986; 160: 585-588.

8 - WESTCOTT JL, COLE SR. Traction bronchiectasis in end-stage pulmonary fibrosis. 8 - WESTCOTT JL, COLE SR. Traction bronchiectasis in end-stage pulmonary fibrosis. Radiology 1986; 161: 665-669. Radiology 1986; 161: 665-669.

9 - MUNK PL, MULLER NL, MILLER RR, OSTROW DN. Pulmonary lymphangitic 9 - MUNK PL, MULLER NL, MILLER RR, OSTROW DN. Pulmonary lymphangitic carcinomatosis: CT and pathologic findings. Radiology 1988; 166: 705-709. carcinomatosis: CT and pathologic findings. Radiology 1988; 166: 705-709.

10 - HANSELL DM, MOSKOVIC. High resolution computed tomography in extrinsic 10 - HANSELL DM, MOSKOVIC. High resolution computed tomography in extrinsic allergic alveolitis. Clin Radiol 1991; 43: 8-12. allergic alveolitis. Clin Radiol 1991; 43: 8-12.

11 - MULLER NL, MILLER RR. State-of-the art: Computed tomography of chronic 11 - MULLER NL, MILLER RR. State-of-the art: Computed tomography of chronic diffuse infiltrative lung diseaseI Am Rev Respir Dis 1990; 142: 1206-1215. diffuse infiltrative lung diseaseI Am Rev Respir Dis 1990; 142: 1206-1215.