Imaging

X-Ray

Introduction

Doctors have used x-rays in medicine for a long period of time. An x-ray is a type of radiation and a specific portion of the electromagnetic spectrum. More specifically, an x-ray is a stream of protons with short wavelengths, which means x-rays are high-energy particles. With the advent of the newer imaging techniques with ultrasound, nuclear medicine and MRI, the use of x-rays is now limited to the initial screening. A chest x-ray is still the most common type of imaging. It gives the overall general view of the heart and lungs. It can detect heart disease such as cardiomegaly and congestive heart failure.

X-rays are utilized for their high energy. X-rays are able to penetrate the human skin, organs, and other body parts. But different parts of the body have different densities. For instance, an x-ray would have a harder time penetrating a solid metal block than penetrating a piece of paper. The paper can’t absorb as many of the high-energy protons as the metal block. So more of the x-rays would go through the paper than the metal block. Similarly, the x-rays have an easy time penetrating skin and fat but have a harder time penetrating more dense parts like bone.

X-ray machines generate a stream of x-rays that penetrate the body. Depending on the densities of the body parts, the remaining x-rays will strike a film. Black parts of the film have little density. The gray parts of the film are somewhat dense. The white parts of the film are what the x-rays had a hard time penetrating and are extremely dense.

The x-ray is a basic cardiac imaging technique often used before any kind of surgery to screen for abnormalities. X-rays give a general sense of health of the organs in the chest. X-rays are inexpensive, painless, and fast. Top

In the lab...

Radiation Amount: Very little. The radiation amount can be less than the radiation emitting from natural sources.

Safety Precautions: An x-ray gown is worn. Any metallic objects, such as jewelry, are removed. No discomfort is felt during the test.

Orientation of Patient: The patient can stand, sit, or lie down in front of the x-ray plate. The x-ray camera is suspended from the ceiling so that different angles can be taken. The patient is told to stand still, because like a camera taking a shot, any movement can make the x-ray blurry. The patient is also told to breathe in and hold his or her breath until the x-ray is done. This make the lungs and the heart show up clearly on the image.

Length of Scan: A few minutes. If a patient moved or didn’t breathe in enough, the length of the scan may change. Top

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