by Allen Alberson

Created on: June 30, 2009   Last Updated: July 03, 2009

When it comes to the field of medical imagining there are several different modalities available. These include X rays, CT, MRI, Ultrasound, and others. Each one has its own set of strengths and weaknesses, pros and cons. Depending on the patient's condition and/or complaint some are more useful than others but they all play an important part. It is up to the physician to determine which modality to use, but it is helpful if the patient knows a little about each before the tests are done. Being informed is the key to a positive experience when you need a diagnostic exam. Here I will attempt to explain a bit about each of the four main modalities in body imaging.

First of all, there are X-rays, commonly called "plain film" or "conventional" x-rays. They are the basis of most imaging departments and still the most widely used. They are the most general exam and can be targeted at specific body parts . They are commonly used if a bone fracture is suspected, but can also be used to help diagnose lung or abdominal viscera problems. One of the major advantages of "plain film" exams is they are relatively inexpensive, especially when compared to MRI and CTs. Due to the cost savings they are many times prescribed for general chest and abdominal problems, before ordering a more expensive but detailed test. Like previously mentioned they are excellent for determining bone fractures. They are the go-to exam for skeletal exams. X-rays are relatively fast and uncomplicated and since portable X-ray tubes are a staple of hospitals, it is possible to image patients who might not be stable enough to transport to the radiology department.

Conventional X-rays do have drawbacks though. They are excellent for bony structures but have limited value in imaging soft tissue. Therefore muscle, tendon and nerve imaging are best left to other modalities. While the skull can be imaged, brain imaging is not feasible for X-rays. A fractured skull will show up but it cannot definitely visualize the brain and so cannot determine if it has been damaged. Plain films are also limited by the size of the object being filmed and the size of the film. The largest films are typically 14 inches long so some bones have to be imaged on two films. They are also limited by being "snap shots" of the body in two dimensions and they provide limited views of the body part. Multiple exposures have to be taken from different angles to provide complete imaging of most body parts. Perhaps on of the biggest concerns

• 1
• 2
• 3
• 4
• 5
• Next Page >>