The CTH medical abbreviation means CT head, a computed tomography study in which a spinning X ray beam and software produce sliced images of the skull and brain. In most cases it is done without contrast dye and takes only a few minutes on the table.
CTH is shorthand that busy emergency, trauma, neurology and hospital teams write in orders and notes. You may also see it as CT head, head CT or NCHCT for noncontrast head CT. This guide covers why the scan is ordered, how to read typical report phrases and how it compares with MRI.
At a glance
What the CTH medical abbreviation refers to
A CT scanner is a ring shaped machine. You lie still on a narrow bed that moves through the opening while an X ray tube spins around the head. A computer turns the data into thin slices that radiologists view on screen. Bone shows up bright white, fresh blood looks bright, and brain tissue appears in shades of gray.
Because it is so fast and widely available, CT head is often the first brain imaging done in an emergency. It is especially good at showing bleeding, skull fractures, swelling and large masses. It is less sensitive than MRI for small or very early strokes and for some subtle brain changes.
Common reasons a CTH is ordered
- A fall or head injury, especially with a blood thinner on board, loss of consciousness or confusion
- Sudden weakness, numbness, facial droop or speech trouble that could signal a stroke
- A sudden, severe headache
- New confusion or a change in mental status, charted as AMS
- A first seizure
- Checking a known bleed or shunt for change
In suspected stroke, CT head helps rule out bleeding before anyone weighs giving tPA, a clot busting drug, which is why it is done as quickly as possible after arrival.
ED note: "78F s/p GLF, on apixaban, hit head. CTH ordered stat." An older woman fell from standing height while taking a blood thinner, so the team wants a fast scan to look for bleeding.
Reading a CT head report
| Phrase | Plain meaning |
|---|---|
| No acute intracranial abnormality | No new bleed, swelling or mass was seen |
| No acute intracranial hemorrhage | No bleeding inside the skull |
| Chronic small vessel ischemic changes | Common age related changes in small brain vessels |
| Subdural hematoma | A pocket of blood under the tough outer lining over the brain, see SDH |
| Midline shift | The brain is pushed toward one side, often by a bleed or swelling |
A negative scan, often charted as CTH neg, means nothing acute was seen. It does not rule out every problem, and some early strokes appear only on later scans or MRI.
CT head, CTA and MRI compared
| Scan | Main strength | Notes |
|---|---|---|
| CTH | Fast; good for blood and bone | Uses X rays; usually no dye |
| CTA head and neck | Shows blood vessels and blockages | Needs contrast dye by vein |
| MRI brain | Detailed soft tissue; early stroke | Uses magnets; takes longer |
In a stroke workup, CT head and CTA are often done back to back, followed by an MRI later if needed. More scan names are explained in the labs, tests and scans hub.
Other uses of the letters
CTH is informal, and not every hospital uses it. Some notes write CT head or head CT in full, which avoids confusion with chest or abdominal scans. When CTH appears in an emergency or neurology note, it almost always means a head CT. If the context is unclear, the radiology order itself will list the exact body part.
A scan report is one part of an evaluation. The doctor who ordered your CT can explain how the findings fit with your symptoms and what comes next.
Frequently asked questions
What does CTH mean in a hospital note?
CTH means CT head, a computed tomography scan of the head and brain. It is commonly ordered after head injuries and for possible strokes.
What does CTH neg mean?
CTH neg means the CT head showed nothing acute, such as no bleeding, swelling or mass. Some problems, like very early strokes, may still need other tests.
Does a CT head use contrast?
Most CT head scans are done without contrast. When contrast is needed, the order will say with contrast, and you may be asked about kidney function and allergies.
How long does a CT head take?
The scan itself usually takes only a few minutes. Getting checked in, positioned and having the images read can add time.
Is CTH the same as CTA?
No. CTH is a plain picture of the head, while CTA uses dye to show the blood vessels. In stroke care both may be done during the same visit.