MRI Scans are becoming increasingly popular as the technology advances, and the cost decreases. MRI scans are much better than X-rays for imaging soft tissue, showing inflammation, detailing blood vessels and creating cross-sectional and 3 dimensional pictures. The risks are smaller than X-rays due to the fact that, unlike X-rays, MRI scanners do not emit harmful radiation, but instead use a combination of magnetic fields and radio waves to generate internal images.Checks must be made to assess whether the MRI patient is free from metal implants due the the powerful magnets that operate in the MRI scanner. Some implants preclude the use of MRI, howeer, other implants are not adverssely affected, but may affect the quality of the diagnostic images. 

MRI and Pregnancy

Sometimes a special dye is injected into the patient (a 'contrast medium') to improve the scanning results. Most these dyes contain rare metals including gadolinium and manganese. There is not enough evidence yet to ascertain the long term effects of this exposure to the foetus. Also, some clinicians have questioned the safety of the foetus due to the head that is generated withing the mothers body during the MRI scan. While there is no proven cases of tissue damage during the procedure, it is generally avoided during the first trimester, and usually only used where there are contraindications highlighted by ultrasound scanning. It is important that you inform your doctor if you suspect you might be pregnant before undergoing any diagnostic images procedures, including X-rays, MRI, and CT scans.

MRI and Bone Scanning

X-rays are routinely used for scanning broken bones, however there are some cases where an MRI is also used. Since X-rays do not highlight soft tissue very well, MRI scans can be used to asses complex orthopaedic injuries where ligaments or tendons may also be damaged. This is likely to occur in sports injuries or crush trauma. MRI scan also detect brusing of the bone, which X-rays cannot detect.

Metal Implants and MRI scans

Not all metal implants prevent the use the MRI scanning, however pacemakers, cochlear hearing implants, or metal clips in the brain which are found in patients with a prior anyeurism are no compatible with MRI scanning. Other implanted metal, such as dental fillings, shrapnel, spinal rods and artificial hip and knee joints do not prevent the MRI scan, but can affect the images produced in that area of the body. Sometimes, metallic based items like drug patches which contain aluminium can heat up during the MRI scanning procedure and potentially burn the patient.