what is the differents between a mri and a CAT scan?

Answer 1

MRI Understanding the Technology: Atoms
The human body is made up of untold billions of atoms, the fundamental building blocks of all matter. The nucleus of an atom spins, or precesses, on an axis. You can think of the nucleus of an atom as a top spinning somewhere off its vertical axis.
A top that is spinning slightly off the vertical axis is precessing about the vertical axis.
A hydrogen atom precesses about a magnetic field.
Imagine billions of nuclei all randomly spinning or precessing in every direction. There are many different types of atoms in the body, but for the purposes of MRI, we are only concerned with the hydrogen atom. It is an ideal atom for MRI because its nucleus has a single proton and a large magnetic moment. The large magnetic moment means that, when placed in a magnetic field, the hydrogen atom has a strong tendency to line up with the direction of the magnetic field.
Inside the bore of the scanner, the magnetic field runs straight down the center of the tube in which we place the patient. This means that if a patient is lying on his or her back in the scanner, the hydrogen protons in his or her body will line up in the direction of either the feet or the head. The vast majority of these protons will cancel each other out -- that is, for each one lined up toward the feet, one toward the head will cancel it out. Only a couple of protons out of every million are not canceled out. This doesn't sound like much, but the sheer number of hydrogen atoms in the body gives us what we need to create wonderful images.
All of the hydrogen protons will align with the magnetic field in one direction or the other. The vast majority cancel each other out, but, as shown here, in any sample there is one or two "extra" protons.
Inside the magnetic field, these billions of extra protons are lined up and ready to go.

CAT Scan
A motor turns the ring so that the X-ray tube and the X-ray detectors revolve around the body. Each full revolution scans a narrow, horizontal "slice" of the body. The control system moves the platform farther into the hole so the tube and detectors can scan the next slice.

In this way, the machine records X-ray slices across the body in a spiral motion. The computer varies the intensity of the X-rays in order to scan each type of tissue with the optimum power. After the patient passes through the machine, the computer combines all the information from each scan to form a detailed image of the body. It's not usually necessary to scan the entire body, of course. More often, doctors will scan only a small section.
Since they examine the body slice by slice, from all angles, CAT scans are much more comprehensive than conventional X-rays. Today, doctors use CAT scans to diagnose and treat a wide variety of ailments, including head trauma, cancer and osteoporosis. They are an invaluable tool in modern medicine.

Answer 2

MRI's or Magnetic Resonances Imaging in three dimensional and deep scanning will be the future. They no longer give you a handful of X-Ray photos but only a disc with interpretations on a computer. The old huge MRI is on the way out, along with CATS. The new MRI is small and quick and above all, super quiet. There no longer a tube you have to be shoved into while that firing of the MRI sounds like machine gun rapid fire and very scary to especially children. The new three dimensional pictures are very real, like the organ itself is out of the body and can be turned and twisted to the doctors advantage. A radiologist should have read your scans, the interpretation is usually left to an expert. If your not comfortable with this ask your doctor and tell him your fears. He should be able to give you an personal opinion of what is shown.

Answer 3

A CT scan is an x-ray. It is less intrusive than an mri, and not as detailed, in it's results. Expect to lie on a table, and have a machine with parts that move, above you. You are in the open. An MRI, (magnetic resonance imaging) requires that you lie on a rolling table. It rolls into a sort of "tunnel," typically. If you are at all claustrophobic, ask your doctor for a mild sedative, and have someone drive you. ALSO - some facilities offer "open" MRI, and GOOD ones give you earplugs. If in doubt, bring your own, and if you have an ipod with earphones, ask about listening to music, throughout the procedure. If you phone ahead and request it, they can set up a music session that you can listen to, to relax you, and to "camoflage" the banging noises of the machine. Be well.

Answer 4

An mri uses magnetic imaging, a cat scan uses radiation like an x-ray.

Answer 5

There are several diagnostic imaging modalities, i.e., CT, MRI, sonogram, xray, PET scan, etc. Each modality has certain advantages and limitations. Therefore, depending on what the doctor is looking for or ruling out, any one or combination of exams may be ordered.

I've provided a website which describes all of them. Besides that site, Webmd.com is always an excellent resource.

Answer 6

An MRI allows you to see soft tissues (based on water contents) and CAT Scan better visualizes bones, looking for a hot spot (higher metabolism area as in cancer) or a cold spot (lower metabolism as in bone cells death). Some Doc office order CAT scan because it is cheaper!!! But the question remains what do we want to assess? Bones (CAT) or Soft Tissues (MRI).

Answer 7

i think mri is any part of your body and a CAT scan is of your head

Answer 8

MRI uses magnets, CT Scan uses XRay

Magnetic resonance imaging (MRI), formerly referred to as magnetic resonance tomography (MRT) or nuclear magnetic resonance (NMR), is a method used to visualize the inside of living organisms as well as to detect the composition of geological structures. It is primarily used to demonstrate pathological or other physiological alterations of living tissues and is a commonly used form of medical imaging. MRI has also found many novel applications outside of the medical and biological fields such as rock permeability to hydrocarbons and certain non-destructive testing methods such as produce and timber quality characterization. [1] The devices used in medicine are expensive, costing approximately $1 million USD per tesla for each unit (common field strength ranges from 0.3 to 3 teslas), with several hundred thousand dollars per year of upkeep costs.

Computed tomography (CT), originally known as computed axial tomography (CAT or CT scan) and body section roentgenography, is a medical imaging method employing tomography where digital geometry processing is used to generate a three-dimensional image of the internals of an object from a large series of two-dimensional X-ray images taken around a single axis of rotation. The word "tomography" is derived from the Greek tomos (slice) and graphia (describing). CT produces a volume of data which can be manipulated, through a process known as windowing, in order to demonstrate various structures based on their ability to block the x-ray beam. Although historically (see below) the images generated were in the axial or transverse plane (orthogonal to the long axis of the body), modern scanners allow this volume of data to be reformatted in various planes or even as volumetric (3D) representations of structures.

Answer 9

mri are xrays of the body from the down point, and cat scans are xrays of inside the body at diferent angles.

Answer 10

Have no idea but i would like to find out.