Search results
Results from the WOW.Com Content Network
CT images of the head are used to investigate and diagnose brain injuries and other neurological conditions, as well as other conditions involving the skull or sinuses; it used to guide some brain surgery procedures as well. [2] CT scans expose the person getting them to ionizing radiation which has a risk of eventually causing cancer; some ...
The dense MCA sign is a dense artery sign observed on non-contrast computed tomography (CT) of the brain and is an important early marker of acute ischemic stroke involving the middle cerebral artery territory. [1] It refers to an abnormally increased attenuation (hyperdensity) of the MCA, reflecting an intraluminal thrombus or embolus.
A CT scan can be performed in under a second and produce rapid results for clinicians, with its ease of use leading to an increase in CT scans performed in the United States from 3 million in 1980 to 62 million in 2007. Clinicians oftentimes take multiple scans, with 30% of individuals undergoing at least 3 scans in one study of CT scan usage. [36]
In CT, X-rays must be blocked by some form of dense tissue to create an image, so the image quality when looking at soft tissues will be poor. In MRI, while any nucleus with a net nuclear spin can be used, the proton of the hydrogen atom remains the most widely used, especially in the clinical setting, because it is so ubiquitous and returns a ...
This type of connective tissue is found mostly in the reticular layer (or deep layer) of the dermis. [3] It is also in the sclera and in the deeper skin layers. Due to high portions of collagenous fibers, dense irregular connective tissue provides strength, making the skin resistant to tearing by stretching forces from different directions.
Using image-guidance—either by a computed tomography (CT) scan or by ultrasound—the interventional radiologist maneuvers the cryoprobe toward the location of the tumor. Next, the cryoprobes are inserted into the tumor to begin freezing it with a gas called argon, creating an "ice ball" over the entire tumor to freeze it for about ten minutes.
A ring-enhancing lesion is an abnormal radiologic sign on MRI or CT scans obtained using radiocontrast. On the image, there is an area of decreased density (see radiodensity) surrounded by a bright rim from concentration of the enhancing contrast dye. This enhancement may represent breakdown of the blood-brain barrier and the development of an ...
Cranial ultrasound is a technique for scanning the brain using high-frequency sound waves. It is used almost exclusively in babies because their fontanelle (the soft spot on the skull) provides an "acoustic window". A different form of ultrasound-based brain scanning, transcranial Doppler, can be used in any age group.