HOW READ CHEST CT -3

ANAS SAHLE ,MD

Basic elements

Ct interpreta

tion

Patient dataAppearance

patternDistribution pattern

clinical

pathology

Radiology

FIGURE 17.3. HRCT Findings in Interstitial Lung Disease

1- Interlobular (Septal) Lines2-Intralobular Lines3-Thickened Fissures4-Thickened bronchovascular structures

5-Centrilobular (Lobular Core) Abnormalities

6- Subpleural lines7-Parenchymal bands8-Honeycombing9-Thin-walled cysts10-Irregularity of Lung Interfaces11-Ground-Glass or Hazy Increased Density

12-Architectural Distortion and Traction Bronchiectasis

13-Conglomerate Masses14-Consolidation

Dot liktree-in-budlldefined

Appearance pattern

Increased lung attenuation

Decreased lung attenuation Nodular opacities Linear opacities

Increased lung attenuation

Ground-glass opacity

Consolidation

Nodular pattern

Size

Appearance

Attenuation

Distribution

WHAT IS DOMINANT PATTERN ?

B-Nodules

Fig. 6.21a,b. (Peri)lymphatic (a) vs centrilobular (b) distribution ofdisease. (a) Patient with sarcoidosis showing numerous subpleural and fissural nodules. Since nodules are also found in other areas where lymphatics are located (peribronchovascularinterstitium, interlobular septa and centrilobular) diagnosisof disease with a (peri)lymphaticdistribution can be made. (b) Patient with infectious bronchiolitis (tuberculosis) showing centrilobularchanges (nodules, branching lines and tree-in-bud), suggesting disease that predominantly involves theairways

1-Dotlike

DOTLIKE :1- pulmonary edema, 2-lymphangitic carcinomatosis, 3-UIP

B-Nodules

FIGURE 17.7. Centri-lobular Ground-Glass Nodules in Sub-acute Hypersensitivity Pneumonitis. HRCT shows the typical poorly defined centri-lobular nodules (arrows) of subacute hypersensitivity pneumonitis (bird-fancier's lung).Caption: Picture 5. High-resolution chest CT scan of a patient with hypersensitivity pneumonitis demonstrates centrilobular nodules. These nodules are unlike those of sarcoidosis, in which the nodules are subpleural and along peribronchovascular interstitium

2- Ill-defined (Ground-Glass) centri-lobular nodules

Ill-defined (Ground-Glass) centri-lobular nodules represent disease of the bronchiole and adjacent parenchyma : 1- subacute hypersensitivity pneumonitis 2-cryptogenic organizing pneumonia (COP),

B-Nodules

Figure 2.  Postprimary active tuberculosis in a 66-year-old woman with a chronic cough. High-resolution CT scans of the right lung show peripheral, poorly defined, small (2–4-mm-diameter) centrilobular nodules and branching linear opacities of similar caliber originating from a single stalk (the tree-in-bud pattern) in the lower lobe (arrow)

3-tree-in-bud appearance B-Nodules

Centri-lobular (Lobular Core) AbnormalitiesTree-in-bud almost always indicates the presence of:

1. Endobronchial spread of infection (TB, MAC, any bacterial bronchopneumonia).

2. Airway disease associated with infection (cystic fibrosis, bronchiectasis).

3. less often, an airway disease associated primarily with mucus retention (allergic bronchopulmonary aspergillosis, asthma).

(Mycobacterium Avium Complex Disease)

Typical Tree-in-bud appearance in a patient with active TB.

B-Nodules

Nodules

Dot-like• pulmonary edema.

• lymphangitic carcinomatosis.

• UIP

tree-in-bud appearance

• Tree-in-bud almost always indicates the

presence of: • Endobronchial spread of

infection (TB, MAC, any bacterial

bronchopneumonia) • Airway disease

associated with infection (cystic fibrosis,

bronchiectasis) • less often, an airway

disease associated primarily with mucus

retention (allergic bronchopulmonary

aspergillosis, asthma).

Ill-defined centrilobular nodulesrepresent disease of the bronchiole and adjacent parenchyma: • in subacute

hypersensitivity pneumonitis

• cryptogenic organizing pneumonia (COP).

Nodular distribution

B-Nodules

B-Nodules

Algorithm for nodular pattern B-Nodules

Sarcoidosis: typical presentation with nodules along the bronchovascular bundle and fissures Notice the partially calcified node in the left hilum.

B-Nodules

•Nodules predominating in the peribronchovascular, interlobular, and subpleural regions those portions of the interstitium where the lymphatics lie are said to have a perilymphatic distribution

sarcoidosis

sarcoidosis

2- Where is it distribution within lung

1-WHAT IS DOMINANT PATTERN ?

LEFT: miliary TB

RIGHT: metastases

4-Conglomerate Masses FIGURE 17.10. Nodules and a Conglomerate Mass in Silicosis. A. Posteroanterior radiograph of a 79-year-old patient with silicosis shows diffuse nodules as well as a conglomerate mass in the right upper lobe (arrow). B. HRCT scan through the upper lobes shows peribronchovascular and subpleural micronodules (small arrows), larger nodules (curved arrow), and a conglomerate mass representing progressive massive fibrosis in the right upper lobe (large arrow). The pleural effusions are caused by concomitant congestive heart failure.

These conglomerate masses are most often seen in patients with end-stage sarcoidosis but can occur in complicated silicosis with progressive massive fibrosis (PMF) (Fig. 17.10) or radiation fibrosis

B-Nodules

Conglomerate Masses:

1- Sarcoidosis 2-Silicosis  3-CWP  4-Radiation fibrosis

NODULAR PATTERN

Sub-pleural nodules

Centri-lobular distributionTree in

bud absent

Peri-bronchiol

ar diseases

peri-vascu

lar disea

ses

Tree in bud

presentPeri-bronchiolar

diseses

Random , uniform distribution

Random distribution

ALSO

Peri-lymphaatic distribution

Peri-bronchovascularSeptalCentri-lobularIn patchy distribution

Absent Present

Regional distribution (nodular pattern)

Upper lung• Histiocytosis • Sarcoidosis• Silicosis

•Pneumocoinosis• Tuberculosis

• RB-ILD

Lower lung• Asbestosis• Organising

pneumonia• Hematogenous

metastases• Alveolar

hemorrhage

Diffuse • Hypersensitivity

pneumonitis• Diffuse pneumonia• Lymphangitic spread

of tumor• Hematogenous

metastases• Sarcoidosis

Regional distribution (nodular pattern)

Central lung• Sarcoidosis

• Silicosis• Pneumocoinosis

•Lymphangitic spread of tumor

Peripheral lung

• Asbestosis• Organising pneumonia

• Hematogenous metastases• Hypersensitivity pneumonitis

• NSIP• Septic emboli

• Small airway disease

Regional distribution (nodular pattern)

Posterior lung

• Sarcoidosis• Silicosis

• Pneumocoinosis• Asbestosis

• Hypersensitivity pneumonitis

Uni-lateral\asymetric• Pneumonia• Sarcoidosis

• Lymphangitic spread of tumor