JC Block C - Diagnostic Radiology - Chest Flashcards
Label
Label
3 main vessel from aortic arch
- Brachiocephalic trunk (right subclavian artery, right common carotid artery)
- Left common carotid artery
- Left subclavian artery
Label
Label
Oblique view: Oblique fissure (X-ray beam tangential to structure) Trachea (slopes backwards) Hilum Diaphragms
Approach to CXR
- How to assess adequacy of CXR
1) Identify name and date of CXR (esp private films)
2) Identify R and L labels
3) Assess technical factors for adequacy:
a) Inspiration: 6 anterior ribs or 10 posterior ribs bisecting hemidiaphragm
When counting posterior, note that the 1st rib is a ring
b) Rotation: medial ends of clavicles equidistant from vertebral spinous process = centrally positioned
c) Penetration: retrocardiac T-spine outline (see-through effect = adequate penetration)
Evaluation checklist for anatomical structures seen on CXR
Check position of the trachea and mediastinum (central?)
Evaluation of lungs: Three zones:
Upper (above anterior end of 2 nd rib)
Middle (between 2nd & 4th ribs)
Lower (below 4th rib)
Compare R and L lungs
Extrapulmonary evaluation Bony rib cage Scapulae and clavicle Supraclavicular fossa Axillary folds (masses) +/- breast shadows
Areas for detailed review on CXR
- ABCDE
Review areas (mnemonic ABCDE): Apex (can have tumor, opacities) Behind the heart Cardiophrenic angles (should be acute) Costophrenic angles (pleural effusion) Diaphragm Edge of film
Areas for detailed review on lateral CXR
Retrocardiac window (occupied by lower lobe containing lung tissue, should be radiolucent)
Retrosternal window (occupied by lung tissue, should be radiolucent)
Diaphragms
Clarity of vertebrae
Posterior cardiac border
Posterior costophrenic sulcus
Causes of mediastinal and tracheal PULL
Ipsilateral (volume loss = pull)
Collapse
Fibrosis
Surgery (pneumonectomy, lobectomy)
Fibrosis – radiological features: Opacification Ipsilateral tracheal deviation Ipsilateral elevation of hilum and diaphragm (normally right hilum lower than left)
Causes of mediastinal and trachea PUSH
Contralateral (mass effect = push)
Large pleural effusion
Tumours
Pneumothorax
Radiological features of pulmonary fibrosis
Fibrosis – radiological features:
Opacification
Ipsilateral tracheal deviation
Ipsilateral elevation of hilum and diaphragm
Radiological features of pleural effusion
Ipsilateral opacification
Contralateral tracheal deviation and mediastinal shift
Note: small pleural effusion does not cause mas
effect
Radiological features of pneumothorax
Hyperlucent (no vascular lung markings)
If tension pneumothorax:
Contralateral tracheal deviation and mediastinal shift
Larger ipsilateral intercostal spaces
Flattening of the ipsilateral diaphragm
Slight depression of ipsilateral heart border
Radiological features of lung consolidation
Alveoli are filled with dense material – could be: Pus (infection) Blood (hemorrhage) Fluid (pulmonary edema) Cancer cells
Radiological features:
Denser lung compared to normal lung
Air bronchograms: see tubular structure transversing
through consolidated lung
Lesion
Cavitation – can be filled with:
Air
Air + fluid
Soft tissue (e.g. fungal ball, tumor)
Ddx Multiple small pulmonary nodules
Infective: tuberculosis, fungal, viral
Neoplastic: miliary metastatic lesions (e.g. thyroid cancer)
Granulomatous: sarcoidosis (uncommon in HK)
Autoimmune: granulomatosis with polyangiitis (formerly called Wegener’s granulomatosis), rheumatoid arthritis
Occupational: pneumoconiosis
If the left and right heart borders are abnormal, which lung segments are affected
Left heart border: Lingula segment
Right heart border: Right middle lobe
2 modalities of CT for lungs
Compare thickness, spacing, resolution, indications
6 modalities of lung imaging
CXR
CT thorax**
Ultrasound: Pleural effusion only
Nuclear scan: Ventilation/perfusion (V/Q) scan: to assess pulmonary embolism (mismatch)
PET/CT – lung cancer staging: staging, metastasis and pleural dissemination
MRI: Only for soft tissue invasion in Pancoast tumor
Case 1:
A young man with sudden pleuritic chest pain and dyspnea:
Hyperlucent left hemithorax (no vascular lung markings)
Interpret
Opacity overlaps with left heart wall – collapsed left lung
Trachea and mediastinum shifted to the right
Larger left intercostal spaces
Flattening of the L diaphragm
Slight depression of left heart border
> > > > Tension pneumothorax
Case 2:
Middle-aged lady with productive cough and fever:
Interpret
Increased density (opacities) in right upper and middle zone
Hazy and indistinct margin
Air bronchograms
> > > Right upper lobe consolidation (consistent with pneumonia)
Case 3:
A 45 year-old lady, a chronic smoker, presents with cough and blood
stained sputum:
Interpret and Dx
Dense triangular shadow behind the heart
Loss of clarity of left hemidiaphragm so pathology should involve the left lower lobe
Displacement of left hilum
Left lower lobe collapse, Suspect malignancy
Case 3:
A 55 year-old lady with sudden SOB:
Interpret and Dx
Cardiomegaly
Bilateral perihilar haze
Upper lobe venous diversion
> > Pulmonary edema in heart failure
Case 4:
Heavy smoker presented with chest pain and haemoptysis:
Thick-walled left upper lung mass
Central lucency suspicious of central cavitation (look for air-fluid level)
Tethering of left hemidparhgam suggests volume loss in left lower lobe
Cavitating left upper/mid-zone mass + suspicious of left lower lobe bronchogenic carcinoma (Opacity behind heart, sitting on diaphragm)
Case 5:
A 17-year old girl with chest pain:
Interpret and Dx
Multiple dense nodules of variable size in both sides of her lung
DDx:
Tuberculosis
Lung metastases
Autoimmune (Wegner’s granulomatosis)
Case 6:
A 68-year-old lady, smoker, presented with haemoptysis
Interpret and Dx
CXR:
Right hilar mass (much bulkier than normal)
Right pleural effusion
Widened superior mediastinum
Suspicious of primary lung carcinoma with malignant right pleural effusion
Need CT thorax for further assessment
Case 7:
CXR of a woman with rheumatoid arthritis:
HRCT:
Ground glass opacity on left
Honeycombing (round cyst-like lesions prominent in lower zone) – irreversible, on right
Case 8:
66-year-old man with sudden pleuritic chest pain; recent long haul flight
Interpret and Dx
CXR:
Wedge-shape peripehral consolidation in LLZ (doesn’t blur hemidiaphragm)
Blunting of left costophrenic angle
Suspicious of pulmonary embolism, pulmonary infarct
CT pulmonary angiogram (CTPA) next to find emboli in pulmonary arteries, any wedge-shaped infarcts
Case 9:
Young lady who had a pre-employment CXR:
Interpret and Dx
Extrapulmonary mass
Pleural-based
Paraspinal
Vertebral/ disc disease
Neurogenic lesions, likely Neurofibroma
if mediastinal lesion extends beyond clavicles (i.e. cervicothoracic sign), it has to be posterior
Cf. anterior: thyroid will not demonstrate cervicothoracic sign
