This is the current version of Pulmonary artery and vein 06/29/00

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

Pulmonary artery

Q: Which component is the reference landmark and why?

• Airways are the reference landmarks Air in lumen serves as a contrast agent for easy recognition

• Constant relationship of pulmonary artery and vein to airways

Aorta

Q: What is the extent, length, orientation, diameter and branches of main pulmonary artery?

• Curves upwards from right ventricle

• Forms a segment of left Heart border

• Bifurcates at the level of Carina slightly left of midline

Q: What is the extent, length, orientation and diameter of right branch of  pulmonary artery?

• Is horizontal,   Horizontal

• Divides into two major branches in mediastinum

• Lies posterior to Aorta and the superior vena cava

• Anterior to right main bronchus

• Divides into Truncus anterior and Interlobar artery

  • Truncus anterior supplies RUL

    • Curves anteriorly and superiorly over upper lobe bronchus

    • Divides into three branches corresponding to bronchial segments

  • Interlobar artery

    • Is larger and passes in front of and along lateral side of intermediate bronchus

    • Transverse diameter measures 15-16 mm during inspiration

    • Enters into oblique fissure

    • Supplies RML and segments of Lower lobe

Q: What is the extent, length, orientation and diameter of left branch of  pulmonary artery?

• Curves upwards and backwards towards hilum

• Passes over anterior and lateral to  left main bronchus

• Slightly higher and posterior than right

• Left hilum higher than right in 97% of normals

• Divides into two branches in hilum

  • Upper division supplies segments (apical-posterior and anterior) of LUL

  • Interlobar artery 

    • Curves sharply over the top of LUL and descends along lateral aspect of LLL bronchus

    • Enters Oblique fissure

    • Lingular branch arises from anterior aspect

    • Superior segmental artery from posterior aspect

    • Supplies branches to LLL basal segments

Pulmonary Veins

Q: Describe the venous drainage of lungs

• Two on either side

• Superior and inferior

• Enter the mediastinum slightly below the pulmonary arteries and anterior to them

• Right superior vein drains RUL and RML

• Right inferior vein drains RLL

• Left superior vein drains LUL and Lingula

• Left inferior vein drains LLL

Q: What are the distinguishing characteristics between veins and arteries

• Course of veins is remote from artery

• Veins begin in lung periphery

• Arteries are in center of lobules

• Veins and arteries are separated by lungs

• Veins run lateral or inferior to respective arteries

• Horizontal topography of veins while arteries have a vertical course especially in lower lobes

CT recognition 

Q: Click to look at the section at the level of Carina. Identify the labeled structures.

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

• RUL pulmonary artery. Artery lies just medial to bronchus

• Right superior pulmonary vein. Vein just lateral to bronchus

Q: You are looking at section at the level of RUL bronchus (at or just below carina).  Identify the labeled structures.

• 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

• Truncus anterior first major branch of right pulmonary artery lies anterior to RUL bronchus

• Branch of right superior pulmonary vein lies at the angle between anterior and posterior segmental bronchi

• Anterior and medial to truncus anterior lies RUL vein (the apical-anterior vein)

Q: You are looking at section at the level of  bronchus intermedius.  Identify the labeled structures.

• 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

• Inferior to bronchus right superior pulmonary vein lies alongside the lateral border of right interlobar pulmonary artery

• Multiple veins can be identified in this location

• Right main pulmonary artery at the lateral border of intermedius bronchus turns inferiorly and becomes interlobar pulmonary artery.

• At this position the artery may have a triangular configuration

Q: You are looking at section at the level of RML bronchus  Identify the labeled structures.

• Interlobar pulmonary artery is vertical and lies immediately lateral to RML and RLL bronchi

• Artery has an oval configuration at this point

• Right superior pulmonary vein lies medial to RML bronchus and can be seen entering the upper portion of left atrium

Q: You are looking at section at the levell of RLL basilar segments  Identify the labeled structures.

• Lower lobe 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

• Branches of right interlobar pulmonary artery are round and lay posterolateral to the proximal portions of basilar segments

• Inferior pulmonary veins are oriented horizontally and can be traced to right inferior pulmonary vein and subsequently into the lower portion of left atrium.

Q: You are looking at section at the level of lower trachea and carina. Identify the labeled structures.

• Apical-posterior segmental bronchus is separated from the left main bronchus by the left main pulmonary artery, which courses over LUL bronchus at this level

• LUL pulmonary artery cab be traced to its origin from the left main pulmonary artery and lies posterolateral to the left superior pulmonary vein

• Superior pulmonary vein tends to be located anteriorly

Q: Left upper lobe

• Forms a sling over which the main pulmonary artery passes

Q: You are looking at section at the level of upper portion of LUL  Identify the labeled structures.

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

• Superior segment of Lower lobe abuts the posterior portion 

• Posterior wall of LUL bronchus is slightly convex because it is indented superiorly and posteriorly by the left main pulmonary artery

  • Posterior to LUL bronchus the left pulmonary artery continues as interlobar pulmonary artery

  • Appears triangular at this level because of the change in course

• Left superior pulmonary vein lies in front of LUL bronchus and has a horizontal course

  • Distinct branching can be identified peripherally

Q: You are looking at section at the level of lower portion of LUL  Identify the labeled structures.

• Left interlobar artery has a vertical course and lies lateral to the spur

• Lateral to the origin of the lingular bronchus the pulmonary artery to lingula can be identified

• Directly anterior to LUL bronchus is the inferior portion of the left superior pulmonary vein

• Pulmonary parenchyma can be seen between pulmonary artery and descending aorta (retro bronchial stripe)

Q: You are looking at section at the level of LLL basilar segments  Identify the labeled structures.

• Branches of pulmonary artery to the lower lobe lie lateral and posterior to the basilar bronchi

• Left inferior pulmonary vein is horizontal and cab traced to left atrium

• Left inferior pulmonary vein course along the lateral border of descending aorta

Read first the text book "Synopsis of Diseases of the chest by Pare and Fraser" by W.B.Saunders company

Roentgenology of the vascular system.

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