#7529 - Cxr Interpretation - Medical Finals & OSCEs Notes

CXR Radiology

Order of examination

Name/marker/rotation/penetration/expansion

Rotation-clavicles equidistant from manubrium

Penetration-should be able to see spinuous processes around heart.

Expansion-on breathing in should be able to see 6 anterior ribs

Lines/Metal

e.g. sternal wiring, arthroplasties

Heart

Measure heart size - <50% of diameter of lung if on PA, not interpretable if AP or shallow breath

Mediastinum

Should be well defined

?Trachea central

Follow hila. Is the hilar density the same on both sides?

Lungs

Look at the upper, middle and lower zones.

Top 2 ribs=upper zone

3^rd + 4^th ribs = middle zone

5^th + 6^th ribs=lower zone

Bones

Trace each rib for # or met

Diaphragm

Follow line from the spine to the costophrenic angle. Flattened? Blunted angles?

Soft tissues

?lymph nodes

?mass

?asymmetry

?surgical emphysema

Pathologies seen on CXR

Penumothorax

-white line of visceral pleura parallel to chest wall

-no lung markings visible lateral to line

-do not confuse line with skin fold or with scapula edge

Simple pneumothoraxmediastinum central. There are commonly small pleural effusions.

Tension pneumothoraxmediastinal shift with trachea leaning away from the pneumothorax side

If surgical emphysema presentsuspect rib #

Do not confuse with emphysematous bullae or a large cyst. Only pneumothorax has a white line parallel to the chest wall.

Causes:

• Spontaneous

• Asthma/COPDburst bullaedestroy visceral pleura

• Trauma

• Connective tissue disease

Consolidation/Alveolar shadowing

Something has replaced the air inside the alveoli. This could be:

• Pus (pneumonia)

• Blood (contusion)

• Water (pulmonary oedema)

• Acid (aspiration)

CXR does not distinguish between these so you must use the clinical picture.

Line misplacement

Central venous catheters should lie in the SVC. This means they should be lateral to the thoracic spine, inferior to the medial end of the right clavicle, above the right hilum since the right hilar vessels enter the SVC. There are complications in 87% of CVPs. This includes misplacement into the right atrium or the wrong vein, arterial puncture, pneumothorax/haemothorax, air embolism or thrombolism. If placed into the right atrium, cardiac rupture and arrhythmias can occur.

NG tubes are used for nutrition, medication or decompression of dilatation. They should be placed with at least the last 10cm coiled in the stomach. The tip should lie below the diaphragm. If they are placed into the bronchi, the patient will cough or be SOB. Ask them to flex the neck or swallow to help go down the oesophagus. To crudely check it is in the stomach, put 10mls of air down with your stethoscope over the stomach and you should hear gurgling on auscultatation.

Intercostal chest drains are used to decompress a pneumothorax or drain a pleural effusion. For a pneumothorax they should be in the lung apex. For a...