Chest Flashcards
What is visible on the chest x-ray (thorax)?
Heart
Lungs
Ribs
Diaphragm
Liver
Spleen
Stomach
Clavicles
Spine
Aortic Arch
Scapula
What is the thorax?
region between the abdomen inferiorly and the root of the neck superiorly. It forms from the thoracic wall, its superficial structures (breast, muscles, and skin) and the thoracic cavity. (Kudzinskas A 2021)
What is the x-ray projections of the chest?
PA Chest
Lateral Chest
AP Chest
What are the clinical indications for a chest x-ray?
Respiratory disease
Cardiac disease
Haemoptysis
Suspectedpulmonary embolism
Investigation oftuberculosis
Pneumonia
Pneumothorax
Suspected metastasis
Follow up of known disease to assess progress
Chronic dyspnoea
Trauma
Pneumoperitoneum
Evaluation of symptoms that could relate to abdominopelvic pathology
Thoracic disease processes
Monitoring of patients in intensive care units
Post-operative imaging
Pre-employment medical fitness
Immigration screening
exclude radiopaque foreign bodies (accidental aspiration,MRI safety screen)
What is the adequacy of an AP chest x -ray?
Apices down to lateral costophrenic angles should be visualised
No superimposition of the chin, arms or scapulae
SC joints are equidistant from the spinous process
Max. of 10 posterior ribs visualised above the diaphragm
The 5th-7thanterior ribs should intersect the diaphragm at midclavicular line
Ribs and thoracic cage are seen only faintly over the heart
Vascular markings of lungs should be clear
What is the Costophrenic angle on an AP Chest?
Diaphragm meets the rib laterally and should be sharp
What organ is under the right hemidiaphragm?
Liver
What organs are under the left hemidiaphragm?
Stomach and Spleen
What is the adequacy of a lateral chest x-ray?
Apices down to lateral costophrenic angles should be visualised
No superimposition of the chin
Superimposition of the anterior ribs
Sternum is seen in profile
Superimposition of the posterior costophrenic recess (think angles)
Min. of 10 posterior ribs are visualised above the diaphragm
Ribs and thoracic cage are seen only faintly over the heart
Vascular markings of lungs should be clear
What is the gold standard chest x ray view?
PA
What circumstances require an AP chest xray?
Very ill, Trauma, Mobile X-ray, immobile patient
Why do we not really use AP chest x-ray?
The heart is further away from the image receptor in an AP chest x-ray which magnifies the heart and reduces the lung field. This is why PA is used instead of AP.
What are the lines of measurement on a PA chest x-ray?
Cardiothoracic Ratio
What is the systematic approach for assessing chest x-rays?
A – Airways and Adequacy
B – Bones & Soft Tissues
C – Cardiac
D – Diaphragm
E – Edges of Heart
F – Fields & Fissures
G – Great Vessels
H – Hila & mediastinum
What is the cardiothoracic ratio?
𝑚𝑎𝑥. ℎ𝑜𝑟𝑖𝑧𝑜𝑛𝑡𝑎𝑙 𝒄𝒂𝒓𝒅𝒊𝒂𝒄 𝑑𝑖𝑎𝑚𝑒𝑡𝑒𝑟/𝑚𝑎𝑥. ℎ𝑜𝑟𝑖𝑧𝑜𝑛𝑡𝑎𝑙 𝒕𝒉𝒐𝒓𝒂𝒄𝒊𝒄 𝑑𝑖𝑎𝑚𝑒𝑡𝑒𝑟
only used on a PA Chest
Normal range is 0.42-0.50
Number outside range = abnormal, likely pathological
A low measurement = Small Heart Syndrome
What is the systematic approach for reading x - ray - Airway and Adequacy?
Airways
Start midline and look bilateral
Trace down the Trachea to the Carina:
Is it straight and midline?
Is there any narrowing?
Trace down both Bronchi:
Is the carina wide (more than 100 degrees)?
Is there bronchial narrowing or cut-off?
Is there any inhaled foreign body?
Left bronchi more horizontal than the right (normal)
Adequacy - PIER
POSITION: is this a supine AP file? PA? Lateral?
INSPIRATION: count the posterior ribs. Should see 10 to 11 ribs
EXPOSURE: well-exposed films = good lung detail and an outline of the spine
ROTATION: SC joints are equidistant from the spinous process
What is the systematic approach for reading x - ray - Bones and Soft Tissue?
Top Bottom
Bone
Shape
Size
Contour
Cortex – smooth and continuous?
Bony lesion? – ZoT - zone of transition, matrix, location etc
Density – increase or decrease
Soft Tissue
Density – increase or decrease?
Swelling/Oedema
Calcification
Air
What is the systematic approach for reading x - ray - Cardiac?
LOCATION
LV on left of image
RA border just visible on the right of the Tx
SIZE = Cardiothoracic Ratio
Normal 0.42 – 0.50
What is the systematic approach for reading x - ray - Diaphragm?
COSTOPHRENIC ANGLES
Sharp and angle inferior
Blunting > effusion
SHAPE
Dome; R higher than L; smooth and continuous
What is the systematic approach for reading x - ray - Edges of the heart?
BORDERS
Clearly visible and defined
Smooth
Not visible? Lung consolidation
What is the systematic approach for reading x - ray - Fields and Fissures?
Zones of the lungs:
Right & left –
Apical
Upper
Middle
Lower
Lung fields – symmetry?
Fissures
Horizontal
Oblique
What is the systematic approach for reading x - ray - Great Vessels?
Right pulmonary artery
Left pulmonary artery
Aortic arch - around T4/T5
Pulmonary trunk
Aortopulmonary window - between aortic arch and pulmonary artery
What is the systematic approach for reading x - ray - Hila and Mediastinum?
Each hilum contains major bronchi and pulmonary vessels
Hilar lymph nodes are not visible unless abnormal
The left hilum is commonly higher than the right
Check the position, size and density of each hilum
Check for widening of mediastinum - could be abnormal - aortic dissection and tracheal deviation
What are Anatomical variants, congenital and acquired abnormalities associated with the chest?
Pectus Excavatum
Eventration
Accessory Fissures
Dextrocardia
Dextrocardia with Situs inversus
Right sided Aortic Arch
Costochondral Calcification
Rib Abnormalities
What is pectus excavatum?
What is it?
Chest wall deformity (m/c)
Concave depression of thesternum
What causes it?
Congenital
How is pectus excavatum diagnosed?
How is it diagnosed?
X-ray: Blurring of right heart border; Increased density of the infero-medial lung zone; Horizontal posterior ribs; Vertical anterior ribs (heart shaped); Displacement of heart towards the left; Widening of cardiac silhouette (due to compression of heart)
Clinical Significance
Usually objectively asymptomatic – BUT most report inability to sustain physical activity
Body-image issues
Can be associated with Marfan’s Syndrome and occur alongside scoliosis, also associated with mitral valve prolapse, cardiac functional abnormalities and restrictive pulmonary function
What is Eventration?
What is it?
abnormal elevation of the dome of diaphragm
What causes it?
Congenital
Failure of muscular development of part or all of one or both hemidiaphragms
M/c anteromedial portion of the right hemidiaphragm
Acquired
Surgery or trauma
Birth trauma – phrenic nerve paralysis
m/c left hemidiaphragm
How is Eventration diagnosed?
X-ray: PA CXR - Elevated portion is usually seen as a smooth dome/bump
Unaffected segments of hemi-diaphragm appear normal.
‘double diaphragmatic contour’, (easily confirmed on a lateral projection)
Clinical Significance
Ddx = paralysis/weakness of complete hemidiaphragm
Different = eventration typically only affects one segment of diaphragm
Can be misdiagnosed as consolidation, lung mass, pulmonary infarction, diaphragmatic mass/rupture or a liver/stomach mass
What are the accessory fissures of the lungs?
Azygos Fissure
M/C accessory fissure
Azygos fissure = laterally displaced azygos vein
Creates Azygos lobe (congenital)
M:F = 2:1
R sided
Left Horizonal (minor) Fissure (LMF)
8% of population on CT
L Lung (only 2 lobes so usually no horizontal fissure)
Dome shaped on projection
Inferior Accessory Fissure (IAF)
12% of population
Commonly incomplete
R lung 5x > L Lung
Superior Accessory Fissure (SAF)
5% of population
May be complete or incomplete
R lung > L Lung
Less common than IAF
What is Dextrocardia?
What is it?
Apex of heart is on the right side of thorax
Cardiac malrotation
What causes it?
Rare Congenital condition
1 in 12,000 pregnancies
How is Dextrocardia diagnosed?
How is it diagnosed?
X-ray: make sure the anatomical marker is correct and you are reading the image the right way round!
The apex of the heart appears in the right side of the thorax, other organs in normal position.
Clinical Significance
On it’s own usually asymptomatic – an incidental finding
Dextrocardia with situs inversus may be symptomatic
What is Dextrocardia with Situs Inversus?
Abnormal positioning of the heart and abdominal organs (totalis)
The positions have flipped
What causes it?
Rare congenital condition
Autosomal recessive
How is Dextrocardia with Situs Inversus diagnosed?
How is it diagnosed?
X-ray: Apex of heart on the right, R-sided Aortic Arch; Gastric air bubble on right (stomach); Left hemidiaphragm higher than right (liver)
Mirror image!
Clinical Significance
20% Kartagener Syndrome
Congenital heart malformations
A lot of the time – asymptomatic and incidental finding
What is a right-sided aortic arch?
What is it?
Right sided placement of the aortic arch (typically a left sided structure)
What causes it?
Rare – Congenital
3 types
How is a right-sided aortic arch diagnosed?
How is it diagnosed?
X-ray: aortic arch silhouette appears on the right side of the trachea; tracheal bowing to the left at the level of the right aortic arch; soft tissue indentation on the right side of the distal trachea
Clinical Significance
Usually asymptomatic – incidental finding
If symptoms – associated with vascular anomalies (vascular ring) due to compression of the oesophagus and/or trachea.
What is Costochondral Calcification?
What is it?
Calcification of the costal cartilage on the anterior rib cage
What causes it?
Increased incidence with advancing age
Age related changes to cartilage composition
Premature calcification <40 years old
malignancy, autoimmune disorders, chronic renal failure, or thyroid disease (Graves disease)
How is Costochondral Calcification diagnosed?
How is it diagnosed?
X-ray: sclerotic appearance of the costochondral cartilage (not normally visualised), may affect all or some of the ribs
Clinical Significance
Potential decrease in inspiration volume
Not to be mistaken for malignant processes
What are rib abnormalities?
FUSED RIBS
1st and 2nd right ribs congenitally fused
BIFID RIB
4th right rib bifid anteriorly
HYPOPLASTIC RIB
4th right rib is small
