For stereotactic biopsies, the experiment consists of six different parts: (1) A baseline
5 min biopsy planning period during which only imaging occurs after patient positioning
and breast compression is complete, (2) One 2-min local anesthesia administration period
during which the skin is injected with local anesthetic and an incision is made to insert
the biopsy needle into the breast occurs ("stressor 1"), (3) One 2-minute post local
anesthesia administration period during which imaging is obtained to confirm the position
of the needle with respect to the target, (4) One 1-minute sampling period when the
breast tissue is sampled ('stressor 2"), (5) One 2-minute post-CNB period, during which
adequacy of obtained samples is confirmed and the need for additional sampling
determined, and (6) One 2-minute period during which a biopsy marker clip is deployed and
pressure dressing placed on the biopsy site.
For ultrasound biopsies, the experiment also consists of six different parts: (1) A
baseline 5 min biopsy planning period during which only imaging occurs after patient is
positioning, (2) One 2-min local anesthesia administration period during which local
anesthesia is given at the site of biopsy and a skin incision performed ("stressor 1"),
(3) One post local anesthesia administration period during which intra-procedure imaging
and confirmation of adequate targeting occurs, (4) One 1-minute first-pass sampling
period ('stressor 2") during which the biopsy device is advanced to the target for the
first time and fired to acquire the first tissue sample, and (5) One 2-minute post-CNB
period, following the first needle pass while sample adequacy is visually assessed and
additional intra-procedure imaging occurs, (6) One 2-minute post-CNB period, during which
a biopsy marker clip is deployed and pressure dressing placed on the biopsy site.
The total time for a single site CNB is approximately 30 minutes when performed under
US-guidance, and 30-45 minutes when performed under stereotactic guidance. The added
physiological recordings for this experiment are not expected to significantly prolong
the duration of CNB procedures.