Chapter 30 - Mediastinum Flashcards
What are the different types of parietal pleural?
Parietal: costal, diaphragmatic, mediastinal
What are the different types of parietal pleural?
Parietal: costal, diaphragmatic, mediastinal
Describe the pareital and visceral pleura and how it borders the mediastinum?
There is a parietal mediastinal layer on the medial aspect of both (right and left) pleural sacs.
Cranially and caudally, there is a reflection of the mediastinum that can be seen radiographically. At this reflection, the parietal reflects onto the surface of the lungs (visceral pleura)
What is the difference between parietal and visceral pleura?
Parietal - borders everything outside of the lung.
Visceral - lies on top of the lungs
Where are the mediastinal reflections seen radiographically on the lateral view?
Cranioventral - ‘bubble’ present in the cranioventral thorax.
This is due to the right cranial lung pushing across midline twoards the left - pushing the cranial mediastinal reflection towards the left side
Where is the mediastinal reflection seen on the DV/VD view?
Cranioventral reflection - separation between right and left. Curvilinear line extending from the cranial aspect of the left heart towards midline. Off of midline due to the right cranial lung.
Caudoventral - extension from the caudolateral aspect of the heart on the left side towards the diaphragm. Displaced off of midline due to the accessory lung lobe.
What structures make up the caudoventral mediastinal reflection?
visceral pleura of the accessory lobe
mediastinal parietal pleura of the right pleural sac
mediastinal parietal pleura of the left pleural sac
visceral pleura of the left caudal lobe
How wide should the cranial mediastinum be on the VD view?
3 types of mediastinal abnormalities?
mediastinal shift
mediastinal mass
pneumomediastinum
Most common cause of mediastinal shift?
atelectasis/decreased lung volume
True/false
Pneumomediastinum can progress to a pneumothorax?
TRUE
True/false
Pneumothorax can progress to pneumomediastinum?
FALSE
What is it called when alveolar rupture leads to dissection of gas into the mediastinal space?
Macklin effect
Difference between sternal lymphadenopathy and mediastinal cyst?
Sternal lymphadenopathy - more cranially located
Mediastinal cyst - incidental findings
What does the sternal lymph node drain?
abdominal structures including peritoneal space, abdominal wall, mammary glands
Differentials for a cranioventral mediastinal mass?
mediastinal lymphadenopathy sternal lymphadenopathy thymoma mediastinal cyst (branchial cyst) ectopic thyroid tumor mediastinal abscess
Differentials for a craniodorsal mass?
Esophageal mass/enlargement (vascular ring, myasthenia, foreign body)
Neurogenic tumor
paraspinal tumor
Differentials for a caudodorsal mediastinal mass?
spirocerca lupi caudal esophageal mass/foreign body hiatal hernia tracheobronchial lymphadenopathy **always take three views to help differentiate between caudodorsal mediastinal mass and a lung mass
What do the cranial mediastinal lymph nodes drain?
muscles of the neck, thorax and abdomen, the last cervical vertebrae, thoracic vertebrae, ribs, trachea, esophagus, thyroid, thymus, mediastinum, heart and aorta
Enlarged tracheobronchial lymph nodes cause ___ displacement of the tracheal carina
cranioventral
Differentials for a caudoventral mediastinal mass?
Something associated with the diaphragm: hernia
Dfiferentials for pneumomediastinum?
Trauma - bite wound from neck, blunt thoracic trauma with rupture of alveoli and Macklin effect
Iatrogenic - overinflation of ET cuff, PPV
Esophageal or tracheal rupture - trauma, foreign body, inflammation, neoplasia
Infection by gas producing bacteria
Describe the pareital and visceral pleura and how it borders the mediastinum?
There is a parietal mediastinal layer on the medial aspect of both (right and left) pleural sacs.
Cranially and caudally, there is a reflection of the mediastinum that can be seen radiographically. At this reflection, the parietal reflects onto the surface of the lungs (visceral pleura)
What is the difference between parietal and visceral pleura?
Parietal - borders everything outside of the lung.
Visceral - lies on top of the lungs
Where are the mediastinal reflections seen radiographically on the lateral view?
Cranioventral - ‘bubble’ present in the cranioventral thorax.
This is due to the right cranial lung pushing across midline twoards the left - pushing the cranial mediastinal reflection towards the left side
Where is the mediastinal reflection seen on the DV/VD view?
Cranioventral reflection - separation between right and left. Curvilinear line extending from the cranial aspect of the left heart towards midline. Off of midline due to the right cranial lung.
Caudoventral - extension from the caudolateral aspect of the heart on the left side towards the diaphragm. Displaced off of midline due to the accessory lung lobe.
What structures make up the caudoventral mediastinal reflection?
visceral pleura of the accessory lobe
mediastinal parietal pleura of the right pleural sac
mediastinal parietal pleura of the left pleural sac
visceral pleura of the left caudal lobe
How wide should the cranial mediastinum be on the VD view?
Less than 2 times the width of the vertebral column
3 types of mediastinal abnormalities?
mediastinal shift
mediastinal mass
pneumomediastinum
Most common cause of mediastinal shift?
atelectasis/decreased lung volume
True/false
Pneumomediastinum can progress to a pneumothorax?
TRUE
True/false
Pneumothorax can progress to pneumomediastinum?
FALSE
What is it called when alveolar rupture leads to dissection of gas into the mediastinal space?
Macklin effect
Difference between sternal lymphadenopathy and mediastinal cyst?
Sternal lymphadenopathy - more cranially located
Mediastinal cyst - incidental findings
What does the sternal lymph node drain?
abdominal structures including peritoneal space, abdominal wall, mammary glands
Differentials for a cranioventral mediastinal mass?
mediastinal lymphadenopathy sternal lymphadenopathy thymoma mediastinal cyst (branchial cyst) ectopic thyroid tumor mediastinal abscess
Differentials for a craniodorsal mass?
Esophageal mass/enlargement (vascular ring, myasthenia, foreign body)
Neurogenic tumor
paraspinal tumor
Differentials for a caudodorsal mediastinal mass?
spirocerca lupi caudal esophageal mass/foreign body hiatal hernia tracheobronchial lymphadenopathy **always take three views to help differentiate between caudodorsal mediastinal mass and a lung mass
What do the cranial mediastinal lymph nodes drain?
muscles of the neck, thorax and abdomen, the last cervical vertebrae, thoracic vertebrae, ribs, trachea, esophagus, thyroid, thymus, mediastinum, heart and aorta
Enlarged tracheobronchial lymph nodes cause ___ displacement of the tracheal carina
cranioventral
Differentials for a caudoventral mediastinal mass?
Something associated with the diaphragm: hernia
What do the tracheobronchial lymph nodes drain
lungs and bronchi primarily (smaller contributions from aorta, esophagus, trachea, heart)
Dfiferentials for pneumomediastinum?
Trauma - bite wound from neck, blunt thoracic trauma with rupture of alveoli and Macklin effect
Iatrogenic - overinflation of ET cuff, PPV
Esophageal or tracheal rupture - trauma, foreign body, inflammation, neoplasia
Gas producing bacteria
