Will a normal CT scan show unruptured aneurysms I had bad headaches yesterday and went to the ER and had a cat scan done. I want to know if CT scan can detect unruptured aneurysms without dye.

Head aches. An er visit and a normal non-contrast ct scan of your head for bad headache is reassuring. However reassuring, this is not the complete evaluation, especially if your headaches persist. The radiology team will recommend additional imaging, MRI or contrast ct scan, to look for aneurysms. This recommendation should be discussed with primary 1st, meds or neurology consult may come before imaging.
Usually. Ct will define aneurysms in most of the body studied. Intracranial may be small and dye can be helpful to demonstrate.
I . I can't make any comment about your headache or its causes, but can try to help with your question "will a normal ct scan show unruptured aneurysms?" a ct (or computerized tomography) scan is a study that uses x-rays and incredibly complicated calculations to make virtual slices of the brain or other body parts. The slices look like grainy black and white photographs (which aren't really just black and white, but many shades of gray). Like in regular x-ray images, the degree of brightness of a tissue has to do with how well it blocks the x-rays. Bones are bright white, while lungs (which are mostly air) are darker. It turns out that quickly-moving blood (like the blood that is traveling in the major arteries that feed the brain) is pretty dark compared to the surrounding skull (white) and brain tissue (shades of gray). Blood that isn't moving any more, most often because it has leaked out of the blood vessels, is usually as bright or brighter than the nearby brain tissue. The difference is usually pretty noticeable to trained eyes, and that's why a plain ct scan is very useful in medical emergencies when it is important to quickly and reliably detect blood that has left the blood vessels (a hemorrhage). There are several types of hemorrhages that can occur in or around the brain. One type, bleeding next to the surface of the brain, called a subarachnoid hemorrhage, can be caused by blood leaking from a weakened section of blood vessel, often from what is called a ruptured aneurysm. Subarachnoid hemorrhage accounts for 10% or less of all patients who come to the emergency room and report a "worst headache ever." by comparison, the consequences of subarachnoid hemorrhage are serious: up to 50% of patients die. So, doctors want to accurately detect every case of subarachnoid hemorrhage they can. It turns out that a plain ct scan, without contrast, on a modern ct scanner can detect 97% or more of all subarachnoid hemorrhages if done within the first 12 hours of onset. Additional tests, such as a spinal tap (also known as a lumbar puncture), can boost that number even more. It is important not to get confused about one fact: all this testing is looking for leaked blood. Leaked blood is considered to be pretty good circumstantial evidence of an aneurysm (or other blood vessel abnormality), but it is not absolute proof. To actually see an aneurysm (ruptured or unruptured... Or other blood vessel abnormality) requires different tests. These tests involve taking pictures of the blood vessels themselves. The absolute best way to do this is by a surgical procedure called angiography or arteriography, in which the doctor inserts a long tube into an artery near your groin or shoulder, and threads it up to the arteries that feed your brain. Dye is injected from the tube into the artery, and digitized x-ray video pictures are taken as the dye passes through the artery. Nonsurgical alternatives include angiograms done on a ct scanner or MRI scanner. These also use dye. Not all of these tests are available everywhere. Most hospitals have a ct scanner, but not all have ct scanners that can do angiograms. Even fewer hospitals have an MRI scanner, and only major hospitals have doctors who do surgical angiograms. All of these tests involve risk, which can sometimes be substantial. Plain ct scans without dye pack a lot of radiation. Ct scans with dye and ct angiograms pack even more radiation, and then there is the risk of the dye itself. The key is to weigh the risk of missing an aneurysm against the risk of doing "just one more" test to find it.