Read first the text book: Computed Tomography and Magnetic resonance of the Thorax by Nadich et all

Then go through this exercise to assess your comprehension

Q!: List Central airways

Answer

Q!: List Central airways

• Trachea

• Carina

• Main-stem bronchi

• Lobar

• Sub segmental bronchi

Q2: Central airways are easily definable with  CT. How are they useful in reading the film?

Answer

Q2: Central airways are easily definable with  CT. How are they useful in reading the film?

• Bronchi are important sites for disease

• Provide road map into the lung parenchyma

• Point of orientation for interpretation of hilum (Bronchi serve as a lattice on which pulmonary arteries and veins drape)

Q3: Describe extent and relationships of Trachea.

Answer

Q3: Describe extent and relationships of Trachea.

• Larynx (C6) to Carina (T5)

• Courses antero-posterior obliquely, hence the position will vary depending on the level of sections

• Progressive caudal sections will show trachea more posteriorly

• Lies anterior and slightly to right of Esophagus

• In contact with mediastinal pleural reflection of RUL (right Para tracheal stripe)

• Potential space between trachea and esophagus and is occupied by lungs (retro tracheal recess) (posterior tracheal band in lateral chest)

Q4: Describe the appearance of Trachea .

Answer

Q4: Describe the appearance of Trachea .

• Cartilaginous and membranous tube

• Cross sectional appearance varies from rounded, oval to horseshoe shaped with a flatter posterior wall

• Thin wall , well defined internally by air and externally by fat

Q4: List  Tracheal Abnormalities

Answer

Q4: List  Tracheal Abnormalities

• Saber sheath trachea: Coronal narrowing associated with sagittal widening

• Squamous cell carcinoma

• Adenocystic carcinoma

  • Propensity for local invasion

• Secondary neoplastic involvement (Cancer esophagus) (Marked irregularity of the wall and lumen)

• Metastases

• Displacement or narrowing by mediastinal masses

• Tracheal stenosis

• Inflammatory diseases (Uniform thickening of tracheal wall)

  • Sarcoid

  • Wegener's

  • Tuberculosis

  • Amyloid

  • Relapsing polychondritis)

• Tracheobronchopathia

• Tracheoesophageal fistula

• Functional evaluation by fluoroscopy in patients with tracheomalacia

 Bronchial anatomy :Ability to visualize depends on

• Size

• Orientation

 Q5: List Bronchi with horizontal orientation

Answer

Q5: List Bronchi with horizontal orientation

• RUL

• Anterior segment

• Posterior segment

• LUL

• Anterior segment

• Middle lobe

• Medial segment

• Lateral segment

• Superior segmental bronchus of Lower lobes

Q6: Bronchi with vertical course (Circular lucencies)

Answer

Q6: Bronchi with vertical course (Circular lucencies)

• Apical segment of RUL

• Apical-posterior segment of LUL

• Bronchus intermedius

• Proximal portion of both lower lobes beyond superior segmental bronchus

Q7: Bronchi with oblique course (difficult to visualize) (oval or elliptical in shape)

Answer

Q7: Bronchi with oblique course (difficult to visualize) (oval or elliptical in shape)

• Lingular bronchus

• Superior segment

• Inferior segment

• Lateral and medial segments of  middle lobe

Q8: Is visualization of bronchi in the periphery normal?

Answer

Q8: Is visualization of bronchi in the periphery normal?

Visualization of bronchi in the periphery of lung is abnormal suggesting thickening of wall or parenchymal disease

Right Lung bronchial segmental anatomy

Five characteristic sections

• Distal trachea carina

• RUL bronchus

• Bronchus intermedius

• Middle lobe bronchus

• Lower lobe bronchus

Q9: At level of distal trachea 

Answer

Q9: At level of distal trachea 

• Apical segmental bronchus of RUL : Circular lucency in association with artery and vein

Q10: At or just below carina

Answer

Q10: At or just below carina

• RUL course horizontally

  • RUL bronchus originates more cephalad than LUL bronchus

  • Above the right main pulmonary artery

  • Posterior wall is in contact with either posterior segment of RUL or superior segment of RLL

• Proximal portions of anterior and posterior segments are visualized

• Origin of apical segment of upper lobe superimposed on the distal portion of RUL as rounded decreased density

Q11: Section at the level of bronchus intermedius

Answer

Q11: Section at the level of bronchus intermedius

• Extends from RUL bronchus to RML bronchus

• Lies directly behind right main pulmonary artery

• Medial to right intralobar pulmonary artery

• Posterior wall in contact with superior segment of RLL

• Azygoesophageal recess is along posteromedially separated by lung tissue

Q12: Section at the level of middle lobe

Answer

Q12: Section at the level of middle lobe

• Middle lobe bronchus origin also marks beginning of right lower lobe

• Extends anteriorly at a slightly oblique angle

• Divides into medial and lateral segments

• Since RML extends inferiorly the medial and lateral segments may be located in a lower plane

• Triangular spur at the site of bifurcation

• Superior segment of RLL arises at the same level as RML or at a slightly lower level

• Superior segment of RLL courses posteriorly and runs in a horizontal plane

Q13: Section at Lower lobe level

Answer

Q13: Section at Lower lobe level

• Lower lobe beyond superior segment is vertical and is recognized as a circular lucency

• Lies medial and anterior to lower lobe pulmonary artery

• Appears suspended by superior portion of the inferior pulmonary ligament

• Medial basilar segment arises first, anterior to inferior pulmonary vein

• Anterior , lateral and posterior basilar bronchi course towards the anticipated positions

Left Lung bronchial segmental anatomy

Q14: Lower trachea and Carina

Answer

Q14: Lower trachea and Carina

• Apical segment

• Posterior segment

Seen as circular lucencies.

Q15: Left upper lobe

Answer

Q15: Left upper lobe

• LUL bronchus originates lower than RUL bronchus

• Forms a sling over which the main pulmonary artery passes

• The LUL bronchus is large

Q16: Section through upper portion

Answer

Q16: Section through upper portion

• Posterior wall is smooth and slightly concave caused by the left pulmonary artery

• The origin of the apical-posterior segmental bronchus can be recognized as area of increased lucency on the distal portion of LUL

• Superior segment of Lower lobe abuts the posterior portion 

Q17: Section through lower portion

Answer

Q17: Section through lower portion

• Left upper lobe spur is the landmark Triangular in shape.

• Spur marks the origin of LLL (secondary carina)

• The lingular bronchus arises from the undersurface of the distal portion of LUL

• Courses obliquely inferiorly

• Can be recognized by increased radiolucency at the distal portion of LUL similar to apical-posterior segment

Q18: Section below LUL bronchus

Answer

Q18: Section below LUL bronchus

• Lingular bronchus is oval or elliptical  separated spatially from LLL bronchus

• Superior and inferior segments originate at a considerable distance from origin of lingular bronchus and often not recognized

Anterior segment of LUL is the only segment coursing anteriorly in a horizontal plane

Highly variable in origin from LUL

Q19: Left Lower lobe

Answer

Q19: Left Lower lobe

• Superior segment of LUL is similar to right side

• Proximal portion of LLL below the superior segment is suspended by the inferior pulmonary ligament

• Basal segments of LLL are similar to right side

• Medial and anterior basal segments arise as a common trunk

Q20: Carcinoid

Answer

Q20: Carcinoid

• Central

  • Well defined tumor, smooth and round or irregular and lobulated

  • Either narrowing, deforming or obstructing an adjacent airway

  • Either with diffuse or punctate calcification

  • Significant homogenous enhancement with contrast

• Peripheral

Atypical carcinoid

• Irregular or spiculated lesion

• Marked heterogeneous enhancement

• Hilar or mediastinal adenopathy

Q21: Bronchiectasis

Answer

Q21: Bronchiectasis

Irreversible dilatation of the bronchial tree

Pneumonia gives reversible dilatation of bronchi

• Localized

  • Infectious

  • Airway obstruction

  • Heat lung transplantation

• Diffuse

  • Mucus inherited abnormalities

Q22: Characteristic findings

Answer

Q22: Characteristic findings

• Crowding and loss of definition of vascular markings due to peribronchial fibrosis and loss of volume

• Discrete cystic spaces

• Cystic spaces with air-fluid levels

• Thickened walls

• Visualization of bronchi in peripheral third of lungs

• When horizontal recognizable as tramlines

• When vertical thick walled, circular lucencies

• Mucus filled airways: mucoid impaction

• Honeycombing caused by fibrosis and emphysema and not by dilated bronchi

Q23: Varieties

Answer

Q23: Varieties

• Cylindrical bronchiectasis: 

• Varicose bronchiectasis : Beaded

• Cystic bronchiectasis: dilated bronchi, air fluid levels, strings and clusters of cysts

• Central bronchiectasis: ABPA

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