Week 6: Respiratory System Pathology Part 2 Flashcards
1
Q
Carcinoma of the Lungs – Bronchogenic Carcinoma
A
- primary carcinoma of the lungs arises from the mucosa of the bronchial tree
- most common lung cancer
- a broad spectrum of appearances, it even mimics other processes, like pneumonia
- precise diagnosis from biopsy, often done under CT guidance
2
Q
Bronchogenic Carcinoma Radiographic Appearance
A
- solitary pulmonary nodule/small round mass (whiter than surrounding tissue due to increased density)
- show only by secondary changes (obstructed or compressed bronchus), atelectasis, pneumonia distal to obstructed bronchus (no air bronchogram sign)
- unilateral hilum enlargement
- cavitation from necrosis of neoplasm center – looks like lung abscess with thick wall & irregular and nodular inner wall
- bronchiolar (alveolar cell) cancer = well circumscribed solitary nodule, poorly defined mass, or multiple scattered nodules throughout both lungs
3
Q
Metastases to the Lungs
A
- cancer from elsewhere in the body may metastasize to the lungs through circulatory or lymphatic channels
4
Q
Metastases to the Lungs Radiographic Appearance
A
- nodules thought the lungs (small or large)
- are round or oval, well defined masses (cannonball lesions)
- military (snowstorm of tiny metazoic deposits)
- poorly defined, coarsened interstitial markings with irregular contours
5
Q
Pulmonary Embolism
A
- embolus (clot, air bubble, fat, debris) transported but the blood stream to the lungs na becomes lodged in the pulmonary artery circulation somewhere
- most arise from DVT of leg
- may be a complication from surgery of the abdomen or pelvis, pregnancy, oral contraceptives, tumors, vascular injury, lower extremity fractures
- can cause pulmonary infarct which may produce pleural effusion
6
Q
Pulmonary Embolism Radiographic Appearance
A
- CXR appears normal or non-specific
- may show lucency in affected part of the lung
- may show enlargement of ipsilateral Ian pulmonary artery
- if infarcted: shows as area of consolidation or Hamptons Hump (pleura based, wedge shaped density with rounded apex of the lung base) or may look like pneumonia
- Ct modality of choice
7
Q
Pulmonary Arteriovenous Fistula
A
- abnormal vascular communication from pulmonary artery to a pulmonary vein
- large one may cause shunting of blood from the arteries to the veins of the lung
- decreases oxygenation which can lead to cyanosis
- may have other vascular malformations (hereditary hemorrhagic telangiectasia)
8
Q
Pulmonary Arteriovenous Fistula Radiographic Appearance
A
- round or oval lobulated mass usually in the lower lobe area
- angiography used for diagnosis
9
Q
Atelectasis
A
- a condition in which there is diminished air within the lung associated with reduced lung volume (typically only part of lung)
- air is unable to enter the part of the lung supplied but the obstructed bronchus and air is absorbed into the bloodstream which cause lung to collapse
- causes: bronchial obstruction, due to neoplasm, foreign body, mucus plug, other or compression due to pneumothorax, pleural effusion, tumour, lung abscess bullae, improper ETT placement
- reversible and preventable with hyperventilation and incentive spirometry treatment
10
Q
Atelectasis Radiographic Appearance
A
- localized increase in density seen as thin platelike streaks or lobar collapse
- displacement of lobar fissures which shift and bow to match contour of collapsed segment
- secondary signs: elevation/tenting of ipsilateral hemidiaphragm (on collapsed side)
- displacement of heart, mediastinum and hilum towards collapsed side
- compensatory overinflation of remaining part of affected lung
11
Q
Acute Respiratory Distress Syndrome (ARDS) - Adult
A
- severe, unexpected, life threatening acute respiratory distress where the lung structure breaks down and there is a massive leakage of cells and fluid into the interstitial and alveolar spaces which cause the lung to fail with fluid
- respiratory impairment causes severe hypoxemia (blood oxygen levels too low)
- from a variety of disorders such as non-thoracic trauma, drug overdose, severe pulmonary infection, aspiration or inhalation of toxins/irritants BUT not no underlying lung disease
12
Q
Acute Respiratory Distress Syndrome (ARDS) - Adult Radiographic Appearance
A
- heart size usually remains normal
- ill defined alveolar consolidation scattered thought lungs
13
Q
Foreign Bodies
A
- may be aspirated, inhaled or penetrated
- in respiratory area, usually aspirated
- intrabronchial usually in young children
- usually lower lobes, right ore than left
14
Q
Foreign Bodies Radiographic Appearance
A
- may see obstructing item if radiopaque
- may cause complete obstruction of major bronchus leading to reabsorption of trapped air, alveolar collapse and atelectasis of segment or lobe
- heart and mediastinum may shift to affected side with elevation of that hemidiaphragm (ipsilateral)
- partial bronchial obstruction maybe seen as hyperinflation (air trapping)
- heart and mediastinum shift to normal contralateral side (during deep expiration and returns to normal during inspiration) (seen if using fluoro)
- may be inhalation/exhalation (insp/exp) CXR for aspiration because forced expiration shows the uncontracted lung well
15
Q
Mediastinal Emphysema (Pneumomediastinum)
A
- are within mediastinal space (space between lungs)
- may be spontaneous due to alveolar rupture and dissection of air along blood vessels to interstitial space in hilum and mediastinum (eg. coughing, vomiting, straining that increases intra-alveolar pressure) OR chest trauma (perforation, tracheobronchial tree, or spreading from other places)
- may cause spontaneous emphysema
16
Q
Mediastinal Emphysema (Pneumomediastinum) Radiographic Appearance
A
- air may outline pulmonary arterial trunk and aorta, and dissect into soft tissue of neck
- AP/PA projection: Lateral displacement of mediastinal pleura due to air, looks like long linear opacity parallel to heart border, but separated by air (vessel dissection)
- lateral projection: collection of air behind sternum, streaking down and anterior to heart
- in infants, thymus elevated and may look like a sail if unilateral or angel wings if bilateral mediastinum
17
Q
Subcutaneous Emphysema
A
- caused by penetrating or blunt injuries that disrupt the lung and parietal pleura
- force air into the tissues of the chest wall
- can feel / hear crepitation if palpate skin (crackling sensation/ sound) in chest, arms, neck
18
Q
Subcutaneous Emphysema Radiographic Appearance
A
Streaks of lucency (air) outlining muscle bundles of chest wall
19
Q
Pneumothorax
A
- air in the pleural space which cause politic pressure on the lung (compresses lung) and collapses lung (partial or complete)
- symptoms: sudden severe chest pain and dyspnea
- causes: due to rupture of subdural bulla from emphysema, spontaneously, penetrating injury (this cause tension pneumothorax), iatrogenic, or hyaline membrane disease in infants
- treat with chest tube
20
Q
Pneumothorax Radiographic Appearance
A
- hyper lucent areas in which all pulmonary markings are absent
- ca see visceral pleural line (lung border)
21
Q
Pleural Effusion
A
- accumulation of fluid in the pleural space (fluid is outside lungs)
- causes: congestive heart failure, pulmonary embolism, infection, pleurisy, neoplasms or abdominal origin (surgery, ascites, subphrenic abscess, pancreatitis)
- may need to increase technical factors
22
Q
Pleural Effusion Radiographic Appearance
A
- blunting of sharp costophrenic angle
- upward concave border of fluid level (meniscus sign)
- white, radiopaque area at angles
- may displace heart and mediastinum to other side if large
- subpulmonic effusion (fluid collected below inferior surface of lung) may appear to elevate hemidiaphragm
- small pleural effusions best seen on lateral than PA/AP but best seen on lateral decubitus
23
Q
Empyema
A
- presence of infected liquid or pus in the pleural space
- causes: spread from a nearby infection, thoracic surgery or trauma
- rare now because of antibiotics
24
Q
Empyema Radiographic Appearance
A
- loculated fluid lesion
- possible air-fluid level if communicates with bronchus or skin surface
- may be discrete mass
- looks like pleural effusion in early stages, then lobulations appear, and maybe air fluid levels
25
Q
Pulmonary Edema
A
- abnormal accumulation of fluid in the lung tissue (fluid is inside lungs) due to decreases pulmonary pressure
- main cause is congestive heart failure
- fluid passes into interstitial spaces (between cells/tissues)
- advances to alveolar and pleural transudates
- alveolar fluid can leak into lungs
- may need to increase technical factors
26
Q
Pulmonary Edema Radiographic Appearance
A
- initially, fuzziness of pulmonary vascular markings
- accentuation of vascular markings about the hila
- alveolar transudates appear as butterfly or bat’s wing pattern of bilateral fan shaped infiltration
- may produce pleural effusion, usually on right side
- cardiomegaly (due to heart failure)
27
Q
Pulmonary Infarct
A
- death (necrosis) of a small area of lung caused by ischemia
- most often due to a pulmonary embolism
- may cause pain in chest or back, hemoptysis, dyspnea or may be asymptomatic presentation
28
Q
Pulmonary Infarct Radiographic Appearance
A
Wedge shaped appearance on CXR and CT scan; often in lower lobe (Hampton’s Hump)
29
Q
Hemothorax
A
- presence of blood in pleural space
- can be from penetrating trauma, disease, iatrogenic or spontaneous causes
30
Q
Hemothorax Radiographic Appearance
A
- looks much like pleural effusion on x-ray image
- blunted costophrenic angle with meniscal fluid shape
- CT can use ROI to determine nature of fluid
31
Q
Sinusitis
A
- inflammation of the mucous membrane of one or more paranasal sinuses (maxillaries, frontals, ethmoids and sphenoid)
- due to blocked sinus drainage
- can be caused by upper respiratory tract infection, microbial infection, allergies, nasal polyps or deviated septum
32
Q
Sinusitis Radiographic Appearance
A
- acute or chronic sinusitis causes mucosal thickening, which appears as a soft tissue density lining the walls of the sinuses
- mucus shows as white area
Horizontal beam required to demonstrate air fluid levels - CT can also be used to evaluate sinuses
