Freehand versus guided breast biopsy: comparison of accuracy, needle motion, and biopsy time in a tissue model.

OBJECTIVE: Freehand ultrasound-guided breast biopsy may present difficulties in needle visualization within the scanning plane of the ultrasound image. Scanning plane and needle misalignment, an unknown needle insertion site (relative to the ultrasound image), needle trajectory before insertion, and physician experience play roles in the difficulty of these biopsy procedures. The objective of our study was to compare the currently used freehand technique with the use of a needle guidance system that limits needle motion to within the ultrasound scanning plane for breast biopsy. MATERIALS AND METHODS: We developed a needle guidance system for breast biopsy that is composed of an electronically tracked passive mechanical arm and braking mechanism. The system was attached to an ultrasound transducer, and biopsy needles were inserted through the guidance arm. Both experienced and inexperienced radiologists performed ultrasound-guided biopsy on simulated breast lesions with and without the guidance system. Success rates were scored on the basis of the presence of lesions in the core biopsy samples. The biopsy procedures were analyzed using procedure time and total needle tip travel distance before firing. RESULTS: The biopsy success rates were greater using the guidance system (p < 0.05) than using the freehand technique. Experienced radiologists and inexperienced radiologists performed biopsy significantly faster using the needle guidance system (p < 0.001). Additionally, needle tip motion was significantly greater when using the freehand technique (p < 0.001) than using the guidance system. CONCLUSION: Biopsy using the developed needle guidance system is feasible and its use decreases procedure time and decreases needle motion; thus, it has the potential to reduce patient morbidity. Moreover, less operator experience is required for a successful breast biopsy using the needle guidance system than using the freehand technique.

Bolus location at the initiation of the pharyngeal stage of swallowing in healthy older adults.

This study characterized the vertical position of the bolus head at the onset of the pharyngeal swallow in healthy older adults. Lateral-view videofluoroscopic (VF) images were obtained from ten healthy volunteers (age-71.6 +/- 7.5 years, mean+/- SD) as they swallowed 5-cc thin liquid barium aliquots. For each swallow, the bolus head and several anatomic landmarks were digitally recorded from the image in which pharyngeal swallow-related hyoid bone elevation began. Vertical distance between the bolus head and the intersection of the tongue base and mandibular ramus (TMI) was computed. Bolus head position at swallow onset ranged from 47.4-mm above to 34.9-mm below the TMI (2.2 +/- 14.4-mm, mean +/- SD). Although the bolus head was below the level of the TMI for the majority of swallows, neither penetration nor aspiration occurred. For individual subjects, mean bolus head position ranged from 25.8 +/- 5.0-mm above to 15.5 +/- 6.5-mm below the TMI. Whereas five of ten subjects initiated the pharyngeal swallow with the bolus head consistently above or consistently below the TMI, five subjects initiated swallowing with the bolus head either above or below the TMI across trials. Older adults commonly initiate thin-liquid swallows with the bolus head well below the TMI without associated penetration or aspiration. Thus, bolus position alone does not differentiate between normal and pathologic swallowing within the healthy elderly. Bolus position at pharyngeal swallow onset can vary substantially from trial to trial within an individual, suggesting that the triggering of swallowing depends on multiple influences.