X-rays are a type of electromagnetic radiation, just like visible light.
An x-ray machine sends individual x-ray particles through the body. The images are recorded on a computer or film.
- Structures that are dense (such as bone) will block most of the x-ray particles, and will appear white.
- Metal and contrast media (special dye used to highlight areas of the body) will also appear white.
- Structures containing air will be black, and muscle, fat, and fluid will appear as shades of gray.
An electrocardiogram (ECG) records the electrical activity of the heart. The heart produces tiny electrical impulses which spread through the heart muscle to make the heart contract. These impulses can be detected by the ECG machine. You may have an ECG to help find the cause of symptoms such as palpitations or chest pain. Sometimes it is done as part of routine tests - for example, before you have an operation.
The ECG test is painless and harmless. (The ECG machine records electrical impulses coming from your body - it does not put any electricity into your body.)
Physical therapy or physiotherapy (sometimes abbreviated to PT) is a health care profession primarily concerned with the remediation of impairments and disabilities and the promotion of mobility, functional ability, quality of life and movement potential through examination, evaluation, diagnosis and physical intervention. It is carried out by physical therapists (known as physiotherapists in most countries) and physical therapist assistants (known as physical rehabilitation therapists or physiotherapy assistants in some countries). In addition to clinical practice, other activities encompassed in the physical therapy profession include research, education, consultation, and administration.
A blood test, also known as bloodwork, is a laboratory analysis performed on a blood sample that is usually extracted from a vein in the arm using a needle, or via fingerprick. Blood tests (also referred to as blood work) are used to determine physiological and biochemical states, such as disease, mineral content, drug effectiveness, and organ function.