lower respiratory system and mediastinum- abnormal appearances

Question 1

what is Chilaiditi sign?

Answer 1

Is the anterior interposition of the colon to the liver reaching the under surface of the right hemi-diaphragm
One of the cause of pseudopneumoperitonuem
Can have Chilaiditi syndrome where patients experience pain

Question 2

Breast implants- assumptions

Answer 2

Makes it look like patients got a chest infection on general x-ray whereas MRI shows it clearly.

Question 3

What is Dextrocardia?

Answer 3

In dextrocardia, the heart is positioned on the right side of the chest instead of its normal position on the left side. Dextrocardia on its own does not usually cause problems, but it tends to occur with other conditions that can have serious effects on the heart, lungs and other vital organs.

Question 4

Hiatus hernia: Description, causes, symptoms, diagnosis, complications, treatment and differential diagnosis

Answer 4

Occurs when there is herniation of the abdominal contents through the oesophageal hiatus of the diaphragm

Causes: Increases with age and slight female predilection

Symptoms: May be symptomatic
Chest / abdominal pain
Nausea and vomiting
Sometimes GORD (gastro-oesophagel reflux disease)

Diagnosis:
Plain film- retrocardiac opacity with air fluid level.
CT- fat collection in middle mediastinum, may see hernia or widened oesophageal hiatus

Complications: Volvulus of stomach

Treatment: Surgery in severe cases

Differential diagnosis: Can make the heart difficult to assess or look like a collection or abscess (mass behind the heart)

Question 5

Pulmonary embolic disease: Description, causes, symptoms, diagnosis, complications, treatment and differential diagnosis

Answer 5

Description
Most commonly a blood clot (which oftenstarts in the leg), which travels through the circulatory system and then causes a blockage in the pulmonary artery – can be partial or complete

Stops blood getting to your lungs.
Lung tissue ventilated but no perfusion.
Struggle to breathe as there is no gas exchange which leads to breathing problems.
Less area of lung to oxygenate.
Which can lead to cardiac arrest.

Causes:
Recent surgery
Immobility
Diseases with a risk of thrombus formation e.g. lupus, HIV, Covid
Drugs such as the contraceptive pill,
Pregnancy
Malignancy

Symptoms:
History fitting any of the causes above
Tachycardia, dyspnea (difficulty breathing), chest pain, hemoptysis
Signs of a DVT

Treatment:
Anticoagulation
CPR if necessary
Differential diagnosis
Movement
Slow flow contrast – poor opacification

Diagnosis
Elevated d dimer
Positive scoring on Wells or other scoring system

Complications
PEA in the case of a cardiac arrest
Right ventricular strain
Pulmonary infarction
Pulmonary hypertension

Question 6

What occurs in Pulmonary embolic disease?

Answer 6

In PE lung tissue is ventilated but not perfused, producing an intra-pulmonary dead space and resulting in impaired gas exchange
After several hours, alveolar collapse occurs which worsens hypoxemia
This leads to a reduction in the cross sectional area of the pulmonary arterial bed which results in elevation of pulmonary artery pressure and a reduction in cardiac output.

The area of lungs that is no longer perfused by the pulmonary artery may infarct but often doesn’t because oxygen is still supplied by the bronchial circulation and the airways

Large or multiple emboli can abruptly increase pulmonary arterial pressure to a level of afterload which cannot be matched by the right ventricle – sudden death may occur, or the patient may suffer from hypotension or syncope which can progress to shock or death due to acute right ventricular failure.

Most common source of PE is DVT in the lower limbs
Chronic thromboembolic pulmonary hypertension (CTEPH) occurs in 0.5-5% of people with treated PE – emboli are replaced by fibrous tissue which can lead to chronic obstruction of the pulmonary arterial vasculature. This leads to progressive increases in pulmonary arterial pressures leading to right heart failure.

Question 7

Pulmonary oedema: Description, causes, symptoms, diagnosis, complications, treatment and differential diagnosis

Answer 7

Description: Accumulation of fluid in the interstitial and alveolar spaces – very broad term! it manifests in 2 types – alveolar and interstitial

causes:
Cardiogenic- (caused by heart)
Congestive heart failure
Cardiomyopathy
Arrythmias
Mitral regurgitation

Non cardiogenic (not caused by heart)
Near drowning
O2 (post intubation)
Trauma
CNS
Alveolitis (hypersensitivity pneumonitis)
Renal failure
Drugs
Inhaled toxins
Altitude- differences in oxygen levels if your high up
Contusion

symptoms: Breathlessness, distress, high heart rate due to fluid in the lungs- blocking gas exchange

diagnosis: CXR – increased cardio/thoracic ratio, upper lobe pulmonary venous diversion, alveolar signs (batwing shadowing, airspace shadowing, consolidation), interstitial signs (Kerley B lines, thickening of the fissures), pleural effusion.
CT – ground glass opacification, septal thickening
US – B lines

complications: Depends on underlying cause, but can result in large pleural effusions. Also leads to impaired gas exchange and can result in respiratory failure.

treatment: Depends on underlying cause

differential diagnosis: Pulmonary haemorrhage
pneumonia

Question 8

Aortic dissection (Type A): description, causes, symptoms

Answer 8

Description​
Separation in the aortic wall intima (tear), allowing blood to flow between the layers of the aortic wall (inner and outer walls of the media). Type A – ascending aorta with or without the aortic arch and descending aorta. Type B – mainly descending aorta and / or abdominal aorta.

Causes​
Risk factors include:
Hypertension
Marfan syndrome- connected tissue disorder
Ehlors-Danlos syndrome- connected tissue disorder

Symptoms​
Acute severe chest pain
Left right blood pressure differential
Pulse deficit
Dyspnoea

Question 9

Aortic dissection: Diagnosis __- imaging is essential to classify the dissection and decide on a treatment plan

Answer 9

CXR - _not specific and may appear normal. However, you may see:
Widened mediastinum
Irregular aortic contour
Deviation of the mediastinum and / or trachea
CT - _Investigation of choice. Sensitivity and specificity of nearly 100%. Needs to be a contrast scan, preferably a CT angiogram. Will see
Dilation of the aorta due to aortic insufficency
Double lumen
MRI - _mainly used in follow ups, but useful in patients with poor renal function. Issues with an acutely unwel patient. Similar snesitivity to CTA
US- _not often used due to availability of CT but can perform transoesophageal echocardioraphy

Question 10

Aortic dissection: complications, treatment and differential diagnosis

Answer 10

Complications __
Organ ischaemia
Stroke
Paraplegia
Aortic rupture
Mortality of 10-35% in hospital

Treatment__
Aggressive blood pressure control with beta blockers to reduce blood pressure and heart rate
Immediate surgical repair

Differential diagnosis_
CXR – any cause of mediastinal widening
CT – pseudo dissection – motion artifact, adjacent adjacent infection
Symptoms – PE, pneumonia, acute coronary syndrome (STEMI, NSTeMI, unstable angina)

Question 11

Pneumonia: Description, causes, symptoms, diagnosis, complications, treatment and differential diagnosis

Answer 11

Description: Broad term to describe acute infection on the lung parenchyma (functional tissue e.g. alveoli)

causes: Infection e.g. COVID 19, bacteria, viral or fungal

symptoms: Productive cough / breathlessness / chest pain
High temperature (pyrexia), sometimes associated with tachycardia
Malaise

diagnosis: CXR – air space opacification
CT – not generally used as the initial diagnostic tool, but useful in cases with complications or for follow up

complications: Empyema
Pulmonary abscess
Bronchopleural fistula- tract between lung and pleura

treatment: Antibiotics
Potentially follow up imaging

differential diagnosis: Consolidation Mass

Question 12

Primary lung cancer: Description, causes, symptoms, diagnosis, complications, treatment and differential diagnosis

Answer 12

Description​
Broad term referring to primary lung malignancy. You may also see the term bronchogenic.

Causes​
Tobacco smoking
Asbestos
COPD

Symptoms​
Patients may be asymptomatic in up to 50% of cases
Hemoptysis- coughing up blood
Cough and dyspnoea
Pleural effusion
Pneumonia

Diagnosis ​
CXR – may see a lung nodule – rounded or irregular area of increased attenuation. May also see a widened mediastinum, pleural effusion or consolidation
CT – nodule or mass with spiculated or irregular margins. Mat see cavitation. Or metastases.
PET-CT – assists with staging and assessment of nodal and distant metastatic spread. The Role of PET Scan in Diagnosis, Staging, and Management of Non‐Small Cell Lung Cancer - Schrevens - 2004 - The Oncologist - Wiley Online Library
MRI - Magnetic Resonance Imaging in Lung Cancer - ScienceDirect

Complications ​
Metastatic spread
Pleural effusions and infections leading to difficulty in breathing

Treatment​
Surgery, chemotherapy, radiotherapy depending on status of tumour
Molecular testing can help with targeted treatments
Differential diagnosis
Consolidation
TB

Question 13

Pleural effusion: Description, causes, symptoms, diagnosis, complications, treatment and differential diagnosis

Answer 13

Description: Is any accumulation of fluid in the pleural cavity – this could be simple fluid, blood, pus etc. Results from many pathological processes which overwhelm the pleura’s ability to reabsorb fluid.

causes: Most common are cardiac failure and malignancy

symptoms: Small amount may have no symptoms
As volume increases symptoms include breathlessness especially when active
Causes are generally split into transudate and exudate. See next slide

diagnosis: US – allows detection of small amounts (3-5ml) and can help guide for pleural taps or drainage.
CT – excellent in detecting small amounts.
CXR – most commonly used imaging method. BUT needs as much as 250mls – 600mls of fluid to see.
Will see blunting of the costo and cardiophrenic angles, fluid within the horizontal fissure, fluid level and may see some mediastinal shift if large.

complications: Lung collapse
Fibrotic changes- scarring

treatment: Targeted to underlying cause
May drain- if it is large

differential diagnosis: Elevated hemidiaphragm
Collapse or conslidation
Pleural thickening

Question 14

Pleural effusion: transudate and exudate

Answer 14

Transudate
Lower protein content (<30g/L)
Occurs when there is an increase in hydrostatic pressure
Cardiac failure
Cirrhosis
Trauma
Post coronary surgery

Exudate
Higher protein content (>30 g/L)
Occurs due to an alteration in the pleural space drainage to lymph nodes
Bronchial cancer
Lung metastases
PE
Pneumonia
TB
Mesothelioma

Question 15

Pleural effusion – AP / Pa erect

Answer 15

Erect films are insensitive to small amounts of fluid
May see blunting of the costophrenic angle
Blunting of the cardiophrenic angle
Fluid within the horizontal or oblique fissure
Eventually a meniscus will be seen, (not with a hydropneumothorax)
Lateral images can identify a smaller amount of fluid

Question 16

Pleural effusion - supine

Answer 16

• Large amounts of fluid can be present on supine image with minimal imaging changes, as the fluid is dependant and collects posteriorly.
• There is no meniscus and only a veil like increased density of the hemithorax may be visible.
• Can be very difficult to identify bilateral effusions as the density will be similar.

Question 17

Pneumothorax: Description, causes, symptoms, diagnosis, complications, treatment and differential diagnosis

Answer 17

Description​
Air in the pleural space

Causes​
Many! Primary generally in younger patients, secondary in older/
Primary spontaneous – no underlying lung disease
Secondary spontaneous – underlying lung disease is present eg COPD older patients
Iatrogenic / traumatic- eg biopsy- tools used for treatment have caused this or trauma.

Symptoms​
Pain and breathlessness

Diagnosis ​
See next slide for plain film findings
CT – considered the gold standard.
Point of care US is more accurate than a supine CXR

Complications ​
Tension pneumothorax
Treatment​
Observation- if it is small
Aspiration- to take out fluid
Chest drain-
Surgery- stitch top of lungs for prevention

Differential diagnosis
Artifacts and monitoring leads
Overlapping breast margin
Pulmonary bullae- alveoli become expanded
Calcified pleural plaques
Pneumomediastinum or pneumopericardium

Question 18

Pneumothorax - more causes

Answer 18

Air entry through the chest wall (outer chest wall)

Trauma
Iatrogenic (biopsy, ventilator)

Air entry through the visceral pleura

Many pulmonary diseases predispose you to pneumothorax including
Cystic lung disease
Bullae
Emphysema, asthma
End stage interstitial lung disease (honeycombing)
Cystic fibrosis
Lung changes from ankylosing spondylitis
Lung abscess – necrotic pneumonia, septic emboli, TB
Cavitating neoplasm
Radiation necrosis

Question 19

Pneumothorax: imaging appearances

Answer 19

AP/PA erect CXR:
Visible visceral pleural edge seen as a very thin sharp white line
No lung markings seen peripheral to this line
Peripheral space is radiolucent compared to adjacent lung
Lung may completely collapse
Mediastinum should not shift unless there is a tension pneumothorax
May also see subcutaneous emphysema or a pneumomediastinum

Does not display classical signs when a patient is supine. May see:
Relative lucency of the involved hemithorax
Deep sulcus sign
Increased sharpness of the adjacent mediastinal margin and diaphragm
Increased sharpness of the cardiac borders
Double diaphragm sign
Depression of the ipsilateral hemidiaphragm

Question 20

Supine CXR- pneumothorax

Answer 20

Deep sulcus sign: The costophrenic angle is abnormally deepened when the pleural air collects laterally

Double diaphragm sign: With apneumothorax air outlines the anterior portions of the hemidiaphragm outlining the anterior costophrenic sulcus – you see the diaphragmatic dome and the anterior portion of the diaphragm

Question 21

What is Pneumoperitoneum?

Answer 21

Gas within the peritoneal cavity
Generally, from a perforated hollow viscus, post operative, from peritoneal dialysis, due to mechanical ventilation, pneumothorax or pneumomediastinum, and many diseases
Patient will often be very ill
On CXR (most sensitive):
Sub diaphragmatic free gas
Continuous diaphragm sign

Question 22

COPD (Chronic Obstructive Pulmonary Disease): Description, causes, symptoms, diagnosis, complications, treatment and differential diagnosis

Answer 22

Description: Is a general term with 2 key disease features – chronic bronchitis and emphysema

causes: Smoking – most common
Cystic fibrosis
Industrial exposure e.g. mining

symptoms: Dyspnoea on extertion
Wheezing
Productive cough

diagnosis: CT – may be as for CXR and also fibrotic changes and bronchial wall thickening for bronchitis and for emphysema – airspace enlargement and possible bulla
CXR – broncitis predominent - increased bronchovascularmarkings and enlarged heart
Emphysema predominent - Hyperinflation of the lungs with flattening of the hemidiaphragms and small heart

complications: Exacerbation – infection, and acute breathlessness
Pulmonary hypertension

treatment: Condition is irreversible, but can manage symptoms and delay progression

differential diagnosis: Pneumothorax if bulla are seen

Question 23

Rib fractures: Description, causes, symptoms, diagnosis, complications, treatment and differential diagnosis

Answer 23

Description: Most commonly due to trauma. When rib is fractured twice it is termed a floating rib. When there are 3 or more, this is a flail chest which indicates severe chest trauma

causes: Trauma
Osteoporosis
Pathological fracture

symptoms: Relevant clinical history
Pain on inspiration or movement

diagnosis: CXR – fracture and displacement seen
CT – better at diagnosing a flail chest

complications: Fracture of 1st rib is an indicator for severe chest trauma as this is protected by the clavicle and scapula.

treatment: O2 therapy as infection is a common complication
Surgery is rare

differential diagnosis: Confusion between pathological and traumatic fracture

Question 24

Goitre: Description, causes, symptoms, diagnosis, complications, treatment and differential diagnosis

Answer 24

Description: Enlargement of the thyroid gland. It can be caused by multiple conditions including – iodine deficiency, thyroid cancer, Hasimotos

causes: It can be caused by multiple conditions including – iodine deficiency, thyroid cancer, Hashimotos.

symptoms: Visible swelling
Tight feeling in throat
Coughing
Difficulty in swallowing or breathing

diagnosis: US can give accurate measurements
CXR – may see deviation of the trachea and a soft tissue mass in the upper mediastinum
CT – as for chest. Also mixed density mass

complications: Difficulty in swallowing and breathing
May need thyroid surgery

treatment: May need surgery if large

differential diagnosis: Enlarged lymph nodes

Question 25

Mesothelioma: Description, causes, symptoms, diagnosis, complications, treatment and differential diagnosis

Answer 25

Description​
Raremalignancy that mostly arises from the pleura

Causes​
Asbestos exposure

Symptoms​
Vague
Dyspnoea
Back pain
Pleural effusion

Diagnosis ​
PET CT is often used for staging as metastases are common
CXR – non specific. Will see pleural thickening with / without a pleural effusion. May see rib destruction.
CT – most commonly used for diagnosis. Will see a pleural, nodular mass. May see invasion into chest wall lung or bones. May see metastases in lung and lymphadenopathy
MRI – not commonly used but may provide more accurate staging

Complications ​
From metastases
Pleural effusion- harder to breathe

Treatment​
Long term survival is poor. Surgery, chemotherapy and radiotherapy can be used.
Differential diagnosis
Pleural effusion
Pleural mass