How can you tell the difference between a ct scanner and a scanner Physically they both look like donut and you are slid in. MRI scanners make a clicking noise.?

Answer 1

A CT scanner works with X-Rays, and an MRI Scanner uses electromagnetic waves. Both machines are operated by specialized technicians, and doctors specialized in radiology. MRI Scanners are far more complex than CT Scanners in the way they function, and in the atomic physics that are behind the making of these images, so often a physicist will work along side the teams that run MRI scanners. A CT Scanner works using x-rays. The patient is slid through on a table through a giant donut shaped machine, whilst an x-ray source and detectors spin around the patient. Using mathematical equations, the data collected from the detectors is analyzed to make a 2D image, or 'slice' of the body. On modern machine, and depending on the region that needs to be explored, the total examination theoretically last less than a minute from start to finish from being installed on the table, to getting up and leaving. Some exams last longer, for example after iodine injections, or for virtual coloscopy. The MRI (Magnetic Resonance Imaging) machines are more complex, but can be summed up as being a large magnet very powerful magnet in which the patient is put through on a table much like in a CT scan. Ariels are placed on the patients body, and images will be made by analyzing the data obtained from from these ariels, which measure the reaction of atoms (mostly hydrogen, which is abundant in our bodies) to variations in the magnetic field. Being a large and extremely powerful magnet, the patient but also the people working with the scanner will have to be careful not to enter the room where the machine is whilst wearing anything metallic or carrying any electronic devices (wrist watches, jewelry, mobile phones, pace makers, some older prosthetic articulations such as hip or knee joints, vascular clips in the brain, etc...). Most MRI exams take far longer than most CT exams, and can last up to 45 minutes to an hour depending on the machine and the reason for doing the exam, but typically it should last no more than 20-30 minutes. For those who don't know much about these machines, here is how to know the difference: - MRI's make far more noise than CT Scanners, often banging noises, or intense repetitive electronic buzzing sounds, and most machines will require you to wear headphones during the duration of the exam; CT scanners will often be much more silent, only making noise when they spin at heigh speed, and sound like an over-sized washing machine. - The famous "!!! RADIOACTIVE !!!" logo should always be displayed on the door that enters the room where a CT scanner is, whereas a pictogram displaying a powerful looking magnet will be displayed in or around an MRI room. - The MRI machine is normally far deeper than the CT Scanner, and once the patient is inside the MRI machine, the table should only move very little whilst images are being taken, whereas the patient in a CT Scanner will continuously be moved whilst the machine rotates around them. - The door to the CT scan looks like a normal door, but will be lined with lead making it rather heavy. The door to the MRI scan will be surrounded with metal studs, and looks more like a bulkhead than a door: this is to ensure that the magnetic field doesn't affect the room and equipment outside of room in which the scanner is kept.