CT Indications

What are some indications, advantages and disadvantages of CT?

Indications

• Trauma: fractures,hemorrhage

• Stroke: Initial evaluation

• Hydrocephalus

• Mass effect/ midline shift

• Detect calcification

Advantages

• Quick, readily available

• Better at evaluating the bony structures especially for fractures

Disadvantages

• Radiation

• Not as good as MR at evaluating the soft tissue structures

Examples of various types of abnormalities seen on CT

These are 4 different patients with different abnormalities seen on non contrast CT

A. This example shows a large hemorrhage which is bright on CT centered within the right basal ganglia. There is surrounding vasogenic edema. Notice the extensive right to left midline shift. Blood has also extended into the ventricular system.

B. This is an example of someone with a stroke involving the right middle cerebral artery distribution. There is a wedge shaped region of low density within the right middle cerebral artery distribution. This patient presented with left sided weakness. There is involvement of the frontal lobe, temporal lobe, parietal lobe and basal ganglia. Given that the abnormality is relatively low in density this is subacute.

C. This is an example of an individual with marked enlargement of the lateral ventricular system consistent with hydrocephalus.

D. This example shows a hyperdense mass within the left lateral ventricle with associated calcification along the periphery