Radiology Flashcards
8 Steps to Interpreting a CXR
- Patient ID
- Type of film (AP or PA)
- Adequacy (penetration, rotation, inspiration)
- Lines and tubes (ETT, OG, chest tube, esophageal balloon)
- Soft tissue
- Bones
- Mediastinum (cardiac silhouette, AP window, trachea, aorta)
- Lungs (lung fields, helium, bronchograms, peri bronchial cuffing)
Correct land marking of ETT on CXR
2cm above carina
Key features of epidural bleed on CT
- Clean mass effect with clear borders between epidural and cranium.
- Lenticular shaped
- Demarcation line against cortex
- Usually associated with skull fractures and torn dural vessels such as the middle meningeal artery.
- Infrequently associated with underlying brain damage but rapid ICP increase can result in secondary brain death.
Key features of subdural bleed on CT
- Non clear (rippled) borders against cranium
- New bleeding shows up as white, while old blood is grey
- Crescent shaped
- Often associated with damage to bridging veins, which drain the cerebral cortical surfaces to dural venous sinuses.
- Often associated with underlying brain damage.
Key features of subarachnoid bleed
- Blood found in ventricles, basal sulci, fissures and/or cisterns.
- Can cause obstructive hydrocephalus (seen as increased ICP and enlarged lateral ventricles)
- Star or spider shaped hyperdensity at level of Circle of Willis.
Key features of intraparenchymal hemorrhage on CT
Intraparenchymal bleeding (white) surrounded by penumbra/edema (grey).
Causes of opacity in a CXR
- Pus
- Blood
- Fluid
- Cells (malignancy)
- Peas and carrots
Steps for interpreting a head CT
Hint: Blood Can Be Very Bad
- Blood (epidural, subdural, SAH, intraparenchymal)
- Cisterns (spaces where arachnoid mater and pia mater are separated)
- Brain (symmetry, grey/white differentation, densification)
- Ventricles (intraventricular bleeding, asymmetry, hydrocephalus)
- Bone (mastoid/sinus air/bleeding, basal fracture)
- On head CT, grey matter has more fat in it so it shows up white while white matter shows up as grey.
What does an EFAST stand for?
Extended Focussed Assessment with Sonography for Trauma.
-It’s a FAST exam, but includes views of both lungs.
What are the five views of the EFAST?
Perihepatic (RUQ) Perisplenic (LUQ) Pelvic (Suprapubic) Pericardial (Subxiphoid) 2 X anterior lung
Does the IVC collapse or distend on a PPV patient on inspiration?
Distends.
On a spontaneous breathing patient, the IVC collapses due to the negative pressure “pulling” blood into the RA.
*Remember, the patient must be supine, in sinus rhythm and on ACV and the IVC must be measured at the level of the hepatic vein in order to be useful. Even then, it’s still representative of a pressure and not a volume.
What is “Gain” when referring to ultrasound?
Amplifies signal in order to make it brighter or darker. Does not improve signal quality.
What is “Depth” when referring to ultrasound?
It’s how far you can see into the tissue. The deeper you go, the greater the lag. Try to concentrate depth on the organ you want to see and no deeper.
What is “Frequency” when referring to ultrasound?
Frequency affects image resolution. The higher frequency probe you have, the higher the quality of image. High frequencies can’t penetrate as deep so you will sacrifice depth for better image quality.
How much fluid is required for a positive FAST in the RUQ region?
200mL (Kanji)
600mL (Perera)… “Hi!”
FAST exam for RUQ (hepatorenal) approach and positive findings…
- Hold probe in long axis view with indicator towards patient’s head.
- Anterior axillary line
- Hepatorenal interface (Morison’s Pouch)
- Right hemothorax (left-posterior side of screen)
- Caudal tip of liver (may need to move down an ICS to view)