An algorithm for automatic needle localization in ultrasound-guided breastbiopsies

An algorithm was developed in order to reduce operator dependence in ultras ound-guided breast biopsy, by automatically locating the needle in the ultr asound image, and displaying its location on the image for the user. Ultras ound images of a typical breast biopsy needle inserted in a tissue-mimickin g agar were obtained to test the algorithm. The resulting images were exami ned by a group of observers who recorded the values of the angle, intercept and tip coordinates of the needle in the image, and inter- and intra-obser ver variability studies were performed on the results. The results of the a lgorithm segmentation were compared to the values recorded by the observers , and physical measurements recorded at the time the images were acquired. The algorithm segmentation was precise enough to successfully (when conside ring angle and tip segmentation) target 90% of tumors of 4.5 mm in diameter situated at the center of the image. (C) 2000 American Association of Phys icists in Medicine. [S0094-2405(00)02808-X].