Biopsy needle characteristics assessed in the laboratory.

Radiologists are frequently called upon to perform percutaneous biopsy. Selection of the proper needle is becoming more complex as the number of types increases and reports of better results with certain needles proliferate. The authors evaluated a wide variety of needles of different caliber, cutting tip, and bevel. Using a standard biopsy technique for in vitro specimens, the samples were analyzed quantitatively by precise weight measurement and qualitatively by cytopathological means. It was concluded that large-bore needles were superior to "skinny" needles, and small-bore needles having an acute bevel angle were superior to flat-bevel needles of similar gauge in terms of specimen size and preservation.