Ddx Flashcards
Ddx mediastinal lymphadenopathy
Sarcoidosis, lymphoma, tuberculosis, lung carcinomas and other cancers
Widespread patchy alveolar infiltrates in both lungs
Broad differentials including
ARDS, fat embolization, aspiration, cardiogenic and noncardiogenic pulmonary edema, pneumoniae, pulmonary hemorrhage, primary alveolar proteinosis
Aortic coarctation
Rib notching
Aortic knuckle figure of 3
Supine radiograph
Signs of aortic injury
Roghtward displacement of the trachea and nasogastric tube
Widen upper mediastinum ( space between aortic knuckle and pul artery
Indistinct aortic knuckle
Depression of left main bronchus
Other suggestive features First or second rib fracture Left hemithorax Lots of paratracheal strip Spinal fracture
Superior mediastinum mass differentials
Adults
Lymphoma teratoma thymoma thyroid thoracic aortic aneurysm
Conditions associated with thoracic aortic aneurysm
Marfan syndrome and connective tissue disorders Hypertension Tertiary syphilis Previous trauma Infection Seronegative arthritides
Pulmonary hypertension
Peripheral pruning - Southern changing colour between the lobar premier arteries and their segmental branches, like a prune tree
Left atrial enlargement
Straightening of the left heart border
double density sign
when the right side of the left atrium pushes into the adjacent lung, and becomes visible superimposed or even beyond the normal right heart border (known asatrial escape)
a similar appearance can be caused by the right superior pulmonary vein in patients without atrial enlargement4
oblique measurement of greater than 7 cm5,6
measured from midpoint of left main bronchus to the right border of the left atrium (this requires a double density sign of course)
thought to be the most reliable sign on chest radiography
convex left atrial appendage (third mogul sign): normally the left heart border just below the pulmonary outflow track should be flat or slightly concave
Indirect signs include:
splaying of the carina, with the increase of thetracheal bifurcation angleto over 90 degrees
this refers to both the interbronchial angle (i.e.angle formed by the central axis of the left and right main bronchi) and the subcarinal angle1-3
both are inaccurate and dependant on radiographer technique, inspiration and body habitus2
the mean and range of both measurements vary widely in normal individuals2,3
interbronchial angle: normal mean 67-77° (range 34-109°)
subcarinal angle: normal mean 62-73° (range 34-90°)
posterior displacement of the left mainstem bronchus on the lateral radiograph
right and left bronchi, therefore, do not overlap, but rather form an upside down ‘V’, sometimes referred to as thewalking man sign5
superior displacement of the left mainstem bronchus on frontal view
posterior displacement of a barium-filled oesophagus or nasogastric tube
Risk factors for sternal dishisence
B/l internal mammary artery graft, diabetes, smoking, obesity, prolong post operative ventilation
Differentials for peripheral consolidation
BOOP bronchiolitis obliterans organising pneumonia Atypical infection not covered by standard ABx TB, coxiella burnetii-QFever,viral,covid Chronic eosinophilic pneumonia Hypersensitivity pneumonitis Drug reaction Vasculitis SLE, Wegener's, ChurgStrauss PE and pulmonary infarction Atypical pulmonary oedema Pul contusion Bronchoalviolar carcinoma
Clues - distribution, lymph nodes on CT
Mx
Some are steroid responsive / lung biopsy
UIP features
Honeycomb lung cyst
interlobular intralobular serial thickening
architectural distortion
Traction bronchiectasis at the lung bases
GGO = active inflammation alveolitis, some are reversible
Interlobular septa reaches pleural whereas blood vessels do not. Usually1-2.5cm long
Cardiogenic pulmonary oedema
Interlobular interstitial septal thickening
GGO
Bilateral pleural effusion
Peribronchial cuffing
No honeycombing or traction bronchiectasis
Cardiogenic pulmonary oedema
Interlobular interstitial septal thickening
GGO
Bilateral pleural effusion
Peribronchial cuffing
No honeycombing or traction bronchiectasis
Interlobular interstitial septal thickening
Broad differentials Idiopathic interstitial pneumonia PCP Pulmonary oedema Lymphanagitis carcinomatosis Dust related disease Sarcoidosis Pulmonary haemorrhage Alveolar proteinosis Chronic hypersensitivity Pneumonitis
Cardiac tamponade
Ecbho signs
Dilated IVC not collapsing with respiration
RV diastolic collapse
Reciprocal variation or RV and LV volume
Resp variation in RV and LV diastolic filling
Validated signs in spontaneously breathing patients
Otto2004
