Ultra sound-guided thyroid fine needle aspiration

Abstract

Fine Needle Aspiration (FNA) is a minimally invasive method for sampling focal lesions that uses a small gauge hypodermic needle (20-24 Gauge) to obtain cells for microscopic analysis. This is in contrast to core biopsy which obtains a core of tissue using larger gauge cutting needles (14-18 Gauge). Both FNA and core biopsies are classified as closed or percutaneous biopsies as opposed to open biopsy that is obtained during surgery.

Ultrasound (US)-guided FNA lends itself particularly well to lesions in superficial organs such as the thyroid, lymph nodes and the breast. However, since it is less traumatic than core biopsy, it is safer for use in highly vascular organs such as the thyroid gland. Smaller nodules are more amnable to FNA, while larger nodules are better sampled with core biopsy.