Non-invasive is a descriptive term for a procedure that 
does not require an instrument or device to be inserted 
into the body (through the skin or through a body 
opening) for diagnosis or treatment. Non-invasive 
procedures are contrasted with invasive procedures 
such as open surgery. However, there are also 
minimally invasive procures such as needle injections 
and small incisions.
 
An ultrasound is non-invasive.
 
The three areas of non-invasive procedures include imaging of the body for diagnosis 
(e.g., x-rays), palpating tissues of the body (e.g., feeling the abdomen to detect organ 
enlargement and/or identify the source of pain), and visual examinations (e.g., skin 
exam). Examples on non-invasive procedures include placing a medicated patch onto the 
skin, taking somebody's blood pressure, taking a pulse, listening to breath sounds, 
hearing tests, vision tests, measurement of height and weight, use of a cast or splint, and 
many others. 
X-rays are traditionally considered non-invasive because no skin break or opening of a 
body part is required. However, the x-rays do technically pass through the skin. Similarly, 
(computerized tomography) scanning is an advanced imaging technique that uses x-rays 
and computer technology to produce more clear and detailed pictures than a traditional x-
ray. MRI scans produce extremely detailed pictures of the inside of the body by using 
very powerful magnets and computer technology. 
 
procedure that uses high-frequency sound waves to produce 
images of internal body structures. Non-invasive also means not 
tending to spread, enter, or intrude into, through, or throughout 
something (such as healthy tissue). This form of the term is 
frequently used in regards to cancer if it does not spread. Cancer is  
any of a large group of malignant diseases characterized by an 
abnormal, uncontrolled growth of new cells in one of the body 
organs or tissues. The opposite of non-invasive is invasive. Non- 
invasive comes from the Latin word "non" meaning "not," the Latin 
word "in" meaning "within," and the Latin word "vadere" meaning "to 
go." Put the words together and you have "not to go within."