Neuroimaging Techniques Quiz

A medical imaging technique that uses X-rays to create cross-sectional images of the body.

A type of CT image where different tissues have different shades of gray based on their density. Fluid appears dark, bone appears bright.

A Nobel Prize-winning technique that uses magnetic fields and radio waves to create detailed images of the brain and other tissues.

A type of MRI image that highlights fluid in the brain, making it easier to see abnormalities like MS lesions.

A type of MRI image that measures the movement of water molecules in the brain, helping to detect brain injury or stroke.

A highly focused beam of X-rays used in CT scans.

X-rays are absorbed differently by different tissues in the body. This difference in absorption is used to create a CT image.

The process of converting the raw data collected during a CT scan into a 3D image.

A type of CT scan that combines continuous gantry rotation with table motion, allowing for faster and more efficient imaging.

A type of MRI sequence where water (CSF) appears dark, while fat (white matter) appears bright. This sequence is used to visualize anatomy.

A type of MRI sequence where water (CSF) appears bright, while fat (white matter) appears dark. This sequence is particularly sensitive to abnormalities like edema and inflammation.

A contrast material used in MRI to enhance the visibility of blood vessels and areas where the blood-brain barrier is broken.

A measure of the brightness of a tissue on an MRI image. It indicates how much signal is being emitted by that tissue.

Low signal intensity on MRI images.

High signal intensity on MRI images.

The simplest and most abundant element in the human body, consisting of one proton and one electron.

The strength of a magnetic field is measured in Tesla (T), where 1 Tesla equals 10,000 Gauss. The Earth's magnetic field is approximately 0.5 Gauss.

MRI uses a strong magnetic field, radiofrequency pulses, and a computer to create detailed images of the body.

In MRI, protons in the body are aligned by the strong magnetic field, then excited by radiofrequency pulses. When the pulses are turned off, these protons release energy, creating a detectable signal.

One MRI study, such as a brain scan or cervical spine scan, is composed of multiple sequences. Each sequence uses specific parameters to create different types of images.

The main types of MRI sequences include T1, T2, FLAIR, and Diffusion Weighted Imaging (DWI). Each sequence highlights specific aspects of the tissue.

A sequence is acquired in one of three planes: sagittal (side view), axial (horizontal slice), or coronal (front view).

MRI works by detecting and processing signals from protons, which are the positively charged particles in the nucleus of hydrogen atoms.

A numeric scale used in CT scans to represent the density of different tissues. Air has a value of -1000, while bone has a value of +1000. Other tissues fall between these extremes.

Describes a tissue that appears brighter than normal on a CT scan, indicating increased density compared to surrounding tissues.

Describes a tissue that appears darker than normal on a CT scan, indicating decreased density compared to surrounding tissues.

Describes a tissue that appears similar in density to surrounding tissues.

Describes a tissue that appears with varying densities on a CT scan, indicating multiple different tissue types.

Rapid, cost-effective imaging modality that is particularly sensitive to detecting bleeding (hemorrhage), bony structures, and calcium deposits. Offers excellent detail of bone and calcium.

Exposure to radiation, limited sensitivity to small structures and soft tissue, metal artifacts can obscure the image. Less sensitive to soft tissues like the spinal cord or pituitary than MRI.

Bleeding within the brain tissue, typically appearing hyperdense on a non-contrast CT scan.

A type of CT scan that involves injecting iodine-based contrast material into the bloodstream. It enhances the visibility of blood vessels and tissues.

A collection of blood that forms between the skull and the dura mater, appearing as a lens or bicovex shape on CT.

A collection of blood that forms between the dura mater and the arachnoid mater, appearing as a crescent shape on CT.

Bleeding into the space surrounding the brain, appearing as wispy densities in the sulci and cisterns on CT.

Damage to brain tissue due to lack of blood flow, typically appearing as low density on CT scan. It may take several hours for the low density to develop.

A type of CT scan that measures blood flow in the brain, providing information about brain perfusion (the amount of blood reaching the brain).

MRI produces detailed images of the brain and other tissues using strong magnetic fields and radio waves.

MRI offers excellent anatomical detail, sensitivity to subtle changes, and is radiation-free. However, it can be time-consuming, claustrophobic, and has limitations with pacemakers or metal implants.

MRI excels in visualizing intracranial tumors, stroke, infections, demyelinating disorders, epilepsy, dementia, hearing loss, pituitary gland, and cranial nerve abnormalities.

Magnetic Resonance Angiography (MRA) uses MRI to visualize blood vessels in the brain and spine, offering a non-invasive way to assess blood flow.

Lymphoma, a type of cancer, can affect the brain either as primary or metastatic disease. On MRI, it often appears as a solid or ring-shaped lesion with surrounding inflammation.

Herpes Encephalitis, caused by HSV-1, shows up on MRI with abnormal signals and enhancement in the medial temporal and inferior frontal lobes, often affecting the limbic system bilaterally, but asymmetrically.

Meningiomas are benign brain tumors typically situated on the surface of the brain. They appear as extra-axial masses on MRI, often with calcification present.

Acute brain infarcts (strokes) show up on MRI with diffusion-weighted imaging (DWI) as a region of restricted diffusion, indicating cell death.

Multiple Sclerosis (MS) is an autoimmune disorder where the protective covering of nerve fibers (myelin) is damaged. MRI reveals lesions in the white matter, often appearing as bright spots in the periventricular region.

A Chiari I malformation involves the downward displacement of the cerebellum into the spinal canal. On MRI, this is seen as a descent of the cerebellar tonsils more than 5mm below the foramen magnum.

Parieto-Occipital Arteriovenous Malformation (AVM) is a tangle of abnormal blood vessels in the brain. On MRI and MRA, it appears as a cluster of abnormal vessels with rapid blood flow.

Basilar Tip Aneurysm, an outpouching of the basilar artery, looks like a round or lobulated bulge on MRA images.

Magnetic Resonance Spectroscopy (MRS) analyzes brain chemicals, allowing for non-invasive evaluation of brain tumors, radiation necrosis, infections, and metabolic disorders.

Diffusion Tensor Imaging (DTI) tracks the movement of water molecules in the brain, enabling visualization of white matter tracts. This helps assess neurological conditions like MS, seizures, and brain injury.

Functional MRI (fMRI) measures brain activity by detecting changes in blood flow, indicating areas of increased neural activity. This is used to understand brain function and map areas involved in specific tasks.