Pleura and pleural space

Question 1

Pleural effusion

Answer 1

Cannot be distinguished on radiographs. Interlobar fissure lines are the earliest sign of excessive fliud in the pleural space and appear as thin, curved, soft tissue opacity lines between lung lobes. (Lateral)

Question 2

Pleural effusion on (DV/VD) keep in mind the _____ _____

Answer 2

mediastinal reflection (cranioventral and caudoventral)

Question 3

Fissure line difference in relation to fluid vs. pleural thickening vs. fat.

Answer 3

Fluid creates fissure lines that are wider periperally and taper toward the hilus. Pleural thickening creates lines that are uniform in thickness and do NOT taper. Fat (obese animals) can fill interlobar fissures and create lines that are wider centrally and taper peripherally. (Reverse fissure lines)

Question 4

Finding in radiographs with increased volume of pleural fluid in realation to lung boarders.

Answer 4

1. Lung borders retract from thoracic wall spine, sternum and diaphram. With large effusions, lung lobes will be small and may appear leaf like. Vascular and bronchial markings do NOT extend to thorachic wall.

Question 5

Finding in radiographs with increased volume of pleural fluid in realation to thoracic cavity contents

Answer 5

Increased opacity, costophrenic angles b/c rounded and indistinct, caudolateral lung margins appear blunted, ventral lung margins b/c scalloped and outlined by fluid, cardiac silhouette and trachea are dorsally displaced (depending on volume of fluid), cranial mediastinum may appear widened due to summation with adjacent fluid, cardiac and diaphragmatic borders b/c obscured, diaphram caudally displaced.

Question 6

Rounding of lung lobe borders suggest ______ ______, which restricts lung ______ and can lead to lung rupture during rapid ______.

Answer 6

pleural fiborsis, expansion, re-expansion

Question 7

Asymmetric or unilateral pleural effusion occurs with _____ _____, which obstruct mediastinal fenestrations and may cause a mediastinal shift ____ from fluid.

Answer 7

inflammatory conditions

AWAY

Question 8

Parietal pleura lines what?

Answer 8

1. thoracic wall
2. mediatinum
3. diaphragm

Question 9

What kind of pleura covers the lungs?

Answer 9

Pulmonary or visceral pleura

Question 10

Parietal pleura flods back on itself at ____ __ ____ to become _____ _____.

Answer 10

root of lungs

pulmonary pleura

Question 11

Types of pleura

Answer 11

• Parietal Pleura
• –Cervical Pleura
• –Thoracic Pleura
• –Diaphragmatic Pleura
• –Mediastinal Pleura
• Visceral Pleura

Question 12

Pleural fluid is continuoulsy produced by ____ ____, released into pleural space and reabsorbed by _____ _____ (75% turnover every____)

Answer 12

Parietal pleura, pulmonary pleura, hour

Question 13

Causes of DECREASED opacity of pleural space is pneumothorax. What are the top 3 causes of pneumothorax?

Answer 13

1. Trauma (common)- erforation of thoracic wall, ruptured lung or airway, tear in pulmonary pleura, ruptured esophagus.
2. Iatrogenic- thoracocentesis, lung aspirate, Thoracotomy, aggressive CPR, transthoracic biopsy of liver, hyperinflation (anesthsia)
3. Spontaneous- idiopathic, rupture from cavitary mass (bleb, bulla, cyst), neoplasia

Question 14

3 reasons for increased opacity in the pleural space and pleura

Answer 14

1. Pleural effusion
2. Pleural thickening
3. Pleural mass

Question 15

Causes for Pleural effusion- first cause for increased opacity in pleural space

Answer 15

Transudate/ modified transudate- Transudate= flid is thin, clear w/ low SG, low protein, low fibrin, and low cell count (results from pressure filtration w/o capillary damage)

Modified transudate= fluid is serous to serosanguinous, may contain a vriety of cell types (often inflammatory) and can lead to restrictive pleuritis or unilateral pleural effusion.

Hemothorax- fluid resembles peripheral blood, but may not clot and is rapidly reabsorbed

Pyothorax or emyema - fluid is exudative w/ lg # of neutrophils

Chylothorax- fluid appears milky due to chylomicrons (small fat globules) and lymphcytes

Pseuro-chylous effusion- (fluid is sterile and inflammatory)

Pyogranulomatous effusion- fluid is thick, viscous, strw colored, exudative w/ very high protein, high SG, few inflammatory cells, fluid may clot

Unilateral or asymmetic PE

Conditions that may mimic PE

Question 16

Effusion types visual-

Answer 16

1. Straw
2. Blood
3. Purulent
4. Chylous

Question 17

Causes of transudate

Answer 17

hypoprteinemia (nephrotic syndrome- glomerulonephritis, protein-losing nephropathy, protein-losing enteropathy, hepatic insufficiency), Iatrogenic fluid overload, CHF (right ventricular fail, pericardial effusion), Lymphatic neoplasia (lymphoma), fibrosis, adhesions

Question 18

Causes of hemothorax

Answer 18

1. Trauma
2. Neoplastic erosion (hemangiosarcoma)
3. Coagulopathy (rodenticide)
4. Autoimmune disease
5. Heartworm disease (errosion through vessel)
6. Sp[irocercosis (errosion through vessel)

Question 19

Causes for pyothorax or empyema

Answer 19

1. systemic infection (most common)- Bacterial, viral, mycotic, nocardiosis, Tuberculosis
2. Foreign material
3. Pneumonia
4. Lung abscess
5. Autoimmune dz (lupus erythematosus, Rheumatoid arthritis)

Question 20

Causes for chylothorax ​

Answer 20

1. MOST COMMON Thoracic duct rupture (iatorgenic, trauma, idiopathic)
2. Thoracic duct blockage (neoplasia, thrombosis, fibrosis, conginital malformation)
3. Lymphangiectasia- is the dilation (expansion) of the lymphatic vessels in thegastrointestinal tract, which includes the stomach, small intestines, and large intestines. Lymphangiectasia is an obstructive disorder of the lymphatic system of the gastrointestinal tract, resulting in the loss of body proteins through the intestines.
4. Heart failure (cats)

Question 21

Causes of Pseudo-chylous effusion (sterile inflammitory fluid)

Answer 21

1. Idopathic (dog)
2. Lymphosarcoma (cat)
3. Cardiomyopathy (cat)

Question 22

Causes for pyogranulamatous effusion

Answer 22

1. MOST COMMON - Feline infectious peritonitis
2. meoplasia (mesothelioma)

Question 23

Causes of unilateral or asymmetrical pleural effusion

Answer 23

1. Functionally complete mediastinum
2. Sever pulmonary dz and altered lung compliance
3. Trapped fluid (unequal distribution, but moves with gravity)
4. Encapsulated fluid (does not move with gravity and retains it’s shape)

Question 24

Conditions that mimic pleural effusion

Answer 24

1. Underexposed radiographs
2. Body conformation- chondrodystrophic breeds (Bassett Hounds, Dachshund) Cats- epaxial musculature in dorsocaudal thorax on lateral radiograph.
3. Obesity- excessive fat along sternum, in mediastinum, and b/t lung lobes

Question 25

Causes if pleural thickening (the second reason for increased opacity in plureal space.

Answer 25

1. previous pleural dz/ aging change
2. Pleural inflammation (pleuritis), systemic- septicemia, viral infection). local dz (pneumonia, trauma, parasitic infection, mediastinitis
3. Pleural fibrosis- “pleural peel”, scarring, or adhesions- exudative pleural effusion (pyo, chylo, hemo, throax)
4. Pleural edema- acute heart failure, sudden trauma

Question 26

Causes of pleural mass - the third cause of increased opacity in the pleura

Answer 26

1. Diaphragmatic hernia (common pleural mass)
2. Primary neoplasia (mesothelioma)
3. Secondary neoplasia (metastatic carcinoma)
4. Abscess or granuloma (FO, parasite, chronic inflammation)
5. Hematoma

6 Mineral or metol opacity

Question 27

Pleural masses and nodules may be caused by rib lesions, pleural masses, or trapped pleural fluid.

Margins of ______ ____ taper cranially and _____ to blend with the thoracic wall.

Answer 27

extrapleural mass caudally

Question 28

Masses in the thoracic wall (extrapleural) bulges into the throacic cavity and create an ______ angle. While nodules inside the lung form _____ angles with the thoracic wall.

Answer 28

obtuse

acute