everal noninvasive diagnostic techniques are commonly used by health-care professionals and students to assess certain aspects of body structure and function. A noninvasive diagnostic technique is one that does not involve insertion of an instrument or device through the skin or into a body opening. In inspection, the first noninvasive diagnostic technique, the examiner observes the body for any changes that deviate from normal (Figure A). For example, a physician may examine the mouth cavity for evidence of disease. In palpation (pal-PA¯-shun; palpa-=to touch) the examiner feels body surfaces with the hands (Figure B). An example is palpating the neck to detect enlarged or tender lymph nodes. In auscultation (aus′-cul-TA¯-shun; ausculta-=to listen to) the examiner listens to body sounds to evaluate the functioning of certain organs, often using a stethoscope to amplify the sounds (Figure C). An example is auscultation of the lungs during breathing to check for crackling sounds associated with abnormal fluid accumulation in the air spaces of the lungs. In percussion (pur-KUSH-un; percus-=to beat) the examiner taps on the body surface with the fingertips and listens to the resulting sound. Hollow cavities or spaces produce a different sound than solid organs do (Figure D). For example, percussion may reveal the abnormal presence of fluid in the lungs or air in the intestines. It is also used to reveal the size, consistency, and position of an underlying structure. An understanding of anatomy is important for the effective application of most of these techniques. Also, clinicians use these terms and others covered in this chapter to annotate their findings following a clinical examination. • CLINICAL CONNECTION | Noninvasive Diagnostic Techniques