Laura Liberman, MD Andrea F. Abramson, #{149} D. David Dershaw, MD MD #{149}Cynthia M. Thornton, Clip Placement Vacuum-assisted PURPOSE: usefulness ing clip assisted AND METHODS: Retrospective review was performed of 57 lesions that underwent placement of a localizing clip after stereotactic vacuum-assisted biopsy with an 11gauge (n = 42) or 14-gauge (n = 15) probe. The clip was placed when images obtained after stereotactic biopsy suggested that the lesion seen at MATERIALS Coordiimages obtained after placement were cornpared with lesion coordinates determined before biopsy. Surgery was performed in 25 cases. Mammographic and histopathologic findings were reviewed. The distance from clip to lesion site was less than 1 cm in 40 (95%) of 42 lesions that underwent clip placement with the 11-gauge probe versus 11 (73%) of 15 lesions that underwent clip placement after 14-gauge biopsy (P < .04). The biopsy site was identified in the surgical specimen in 19 (100%) lesions with clips after 11-gauge biopsy and five (83%) of six lesions with clips after 14-gauge biopsy. No cornplications occurred. RESULTS: A localizing clip can be placed in proximity to the stereotactic biopsy site through an 11-gauge probe. Clip placement can enable accurate localization for surgical excision. CONCLUSION: A. Morris, MD #{149} Paul Peter Rosen, MD after Stereotactic Breast Biopsy’ To assess accuracy and of placement of a localizafter stereotactic, vacuumbreast biopsy. mammography was removed. nates of the clip on stereotactic Elizabeth RT(R)(M) #{149} were radiopaque localizing clip has been approved by the U.S. Food and Drug Administration for placement after directional, vacuumassisted breast biopsy (1-3). The goal of clip placement is to enable subsequent surgical excision of the biopsy site, even if the mammographic findings sion associated with the original were removed completely. or may have pletely. Clips Biopsies leTo with opsy reotactic, vacuum-assisted fered as an alternative for mammographically was instrument bowl mm 14-gauge and for the probe The were Biopsies were performed for dian of 13 specimens around increments tion suggested findings Index 00.31, that Radiology . with Biopsies, Stereotaxis, 1997; tissue the acquisi- technology, 00.1261 requests RSNA, See also © with patients (mean, per lesion. a minimum per lesion 14; range, The of eight by rotating the face (1-5). 8- protocol speci- the aperture of the clock Additional of the radiologist Breast, biopsy, 00.1261 performing #{149} Breast the biopsy. neoplasms, diagnosis, 205:417-422 I From the Departments of Radiology, Breast and Pathology (P.P.R), Memorial Sloan-Kettering Received May 6, 1997; revision requested June reprint in specimens were obtained to sample a larger area of breast tissue at the discretion lesion 00.1261 obtained to obtain mens stereo- original were was the mammographic associated terms: 00.32 after in the study. on a dedicated table (StereoGuide DSM; LoRad, Danbury, Conn). The 11gauge probe was placed to a depth 2 mm proximal to the calculated depth of the center of the lesion to acquire tissue. A me- in 1.5-hour obtained in 39 median, prone of the bowl tactic images years; two. The median lesion size was 7 mm (mean, 7 mm; range, 2-15 mm). after when the 11- 42 lesions 43-81 included 34) biopsy through remaining the 11-gauge probe). No lesions were cxcluded because of small size. A 2 X 2-mm radiopaque localizing clip (MicroMark; Biopsys Medical, Irvine, Calif) was placed vacuum-assisted placed findings in these 42 lecalcifications in 26, uncalcified in 14, and mass and calcifications mass (22 27 mm and Biopsys Mammographic sions were to accommodate probe was (age range, patients 24, 1997, ste- of the biopsy Probes (Mammotome; clip localizing biopsy was ofto surgical biopsy evident lesions in inadequate the tip 11-gauge gauge probe after biopsy. Two lesions were excluded because the stereotactic images obtained after clip placement were not which surgery would otherwise have been performed unless (a) the patient had a bleeding diathesis, (b) the patient was unable to tolerate the procedure, or (c) the thickness of compressed breast parenchyma of stain- Medical) from October 31, 1996, to April 24, 1997. In 44 (46%)lesions, the radiopaque METHODS May 1, 1996, to April 5, 1997, used Retrospective review was performed of mammograms of 96 consecutive lesions that underwent stereotactic biopsy with an 11-gauge directional, vacuum-assisted bi- 58 years) From com- February of titanium; clips less steel. available. AND removed before were constructed after that time were constructed date, there is little published expenience with regard to use of the clip, to our knowledge (1-3). This study was undertaken to assess the accuracy and usefulness of placement of a localizing clip after stereotactic, vacuum-assisted breast biopsy to enable subsequent surgical excision of the biopsy site. MATERIALS been used Imaging Section (L.L., D.D.D., E.A.M., A.F.A., C.M.T.), Cancer Centet 1275 York Ave. New York, NY 10021. 5; revision received July 21; accepted July 23. Address to L.L. 1997 the article by Burbank and Forcier (pp 407-415) in this issue. 417 ‘p -. a. f. e. b. C. Figure 1. woman. Clip placement (a) Collimated through the il-gauge craniocaudal mammogram probe in a 63-year-old demonstrates a clus- ter of pleomorphic calcifications measuring 1.0 cm in the longest dimension. (b) Stereotactic images obtained after acquisition of the first specimen reveal the probe in proximity to the remaining calcifications. (c) Stereotactic images obtained after tissue acquisition show air and hematoma at the biopsy site. No residual calcifications are identified. (d) Stereotactic images obtained after suctioning and clip placement show air at the biopsy site. The clip is attached to a side wall of the biopsy cavity. Collimated (e) craniocaudal mammogram and (f) mediolateral oblique mammogram obtamed after clip placement demonstrate the biopsy cavity and accurate positioning of the clip. Histopathologic analysis revealed benign breast tissue with adenosis and microcalcifications. d. The decision mens of the to obtain was based specimens cifications, on results in lesions visual specimens, images. radiography tissue the biopsy the cutter at 22 kVp was complete, ply continuous the off bank F, oral Stereotactic the the vacuum button to ap- to the bowl, bowl 360#{176} twice communication, images were biopsy to ascertain findings associated had been removed. back “VAC” vacuum open and the tip of the cutter was at the proximal end of the bowl. The operator toggled the May obtained and manually cavity was suctioned by pulling all the way back, turning off the and of the bowl ing the dial 1996). after ter lumen, system. of the The tional location used (3). the probe 418 #{149} Radiology maneuver, the cutter end of clip of the lated probe to be collected, to distal then The around on into cleared the cut- The an addi- first to a calcu- ducer, the with the basis respect (z) direction, to the initial direction face of clip of the of (a) the clock location to the lesion was of on pre- clip The was marks by probe was the pulling withdrawal, tamed on clip aperture opening to the applied was then squeeze of introducer, to the of the probe tubing in the advanced black was axis. first selectively chamber) vacuum mark deployed handles, and clip introducer the the the to the desired on the clip was clip and introduced to the second the squeeze leased. The turning probe introducer vacuum the if the by of the bowl (collecting pinching off the from withdrawn placement bowl black two and position; the clip was placed in the 6-o’clock The radiologist set the direction of the clip back. was z coordinate. chosen pulled and 5 mm in the depth 7 mm proximal placement this the proximal 12-o’clock “high,” position. and back many times by turnon the probe driver. Additional probe Clip placement through the li-gauge probe is illustrated in Figure 1. Before clip placement, the “tap tap” maneuver was To perform the the short bursts of vacuum were applied while the cutter was pulled back. This maneuver allowed tissue fragments in the bowl or shaft lesion manipulated from (Bur- if the mammographic with the original postfire stereotactic images and (b) images obtained after tissue acquisition. If the probe was “low” with respect to the lesion, for example, the clip was placed in cutter was pulled back, the vacuum was shut off, and the front vacuum tube was pinched off. The cutter was then brought forward to the precut stop position so that vacuum acquisition pressing rotating tissue of stereotactic calcifications, was per- magnification pinching tubing, of the and assessment In lesions containing of the specimens After speci- of radiography evident as cal- inspection formed with X1.8 and 4 mAs (3). vacuum, additional from by the on the introby pressing vacuum was rewas withdrawn handles; forward pressure the hub of the clip during was mainintroducer November 1997 . Table 1 Location of the Clip Lesion Site Relative After the side gauge calibrated (Manan Medical to was Biopsy Method : - I- Distance on Stereotactic Images (mm) 11-gauge (n = 42) 14-gauge (n = 15) 0 Total Median Mean Range 5.6 5.5 2.3-12.0 <5mm 5-9 mm lOmm 22 (52)* 6.7 7.9 1.5-26.8 18(43)* 4(27)* 7 (47)* 2(5)* Figure 4(27)* Radiograph from 1.0 1.2 0.9 1.4 Range 0.0-3.6 0.2-3.8 attached Mean Range 3.1 3.0 0.2-5.9 1.5 2.3 0.7-6.1 Median 3.8 5.6 sions 3.8 0.3-11.9 6.9 0.2-26.6 error Deep Superficial 23 (55)* 19 (45)* 11 (73)* to the number placing lesion Numbers are percentages. to the depth of the clip relative needle in with in which hub. After the clip drawn emerged from introducer completely, the was bowl were obtained firm clip The The after clip placement images were the coordinates of the clip aper- from May cording clip site any direction the absolute tween on reviewed. ment obtained stereotactic from clip to lesion ages was calculated the sum distances, images of the The clip total square of the squares of the per the Pythagorean as imroot of x, y, and theorem z (6). A mammogram was obtained after bi- the location opsy site toma was tained of the clip on standard after biopsy in 29 (69%) obtained gested that lesion was the original removed lesions Volume Surgical included in five 205 procedures mastectomy Number and 2 and placed were after not obtained; in 20 excluded clip place- the remaining 15 in the study. These in 15 patients (age median, 56 years). A of 16 specimens (mean, 17; range, were obtained per lesion. Mammographic findings in these 15 lesions were calcifications in 11, uncalcified mass in two, and mass and calcifications in two. The median lesion size was 4 mm (range, 3-10 mm). Clip placement after 14-gauge vacuumassisted biopsy differed from clip placement through the 11-gauge probe. Because the clip cannot be placed through the 14probe, the the biopsy reotactic probe was withdrawn cavity was were obtained images essary for ploy in the suctioned. Ste- and a side the clip to attach breast. It was to tissue believed The necto de- prefer- of 42 ledimin- breast. Targeting placement performed on after clip in seven excision was able for the clip to attach to a side wall of the biopsy cavity rather than to a near or far wall owing to potential error in the depth (z) direction in the compressed sug- mammographic patients #{149} ob- biopsy in 30 (71%) clip ac- previ- wall of the biopsy cavity was targeted. side wall was targeted because it was of 42 lesions. after sions, obscured in 10 (24%), ished in two (5%). Surgery was subsequently 19 lesions. placement in Hema- on mammograms 30, 1996, described 8-39) gauge to the bi- projections. observed Mammograms relative to October protocol A localizing were after opsy that consisted of craniocaudal and mediolateral oblique views of the breast which biopsy was performed to ascertain bi- median and the distance site on stereotactic as the 11-51 days) after stereotactic 14- biopsy. Needle and surgical histopathologic findings were reviewed. Data were analyzed with a computerized statistics program (Epi-Info; Centers for Disease Control, Atlanta, Ga). Statistical significance of results was determined with the 2 and Fisher exact tests. Table vacuum-assisted lesions were included 15 lesions occurred range, 43-80 years; in (x, y, or z) was calculated value of the difference be- the coordinate in that direction. lesion ob- RESULTS performed lesions (24%) lesions. Five lesions because stereotactic images on the clip and were cornwith coordinates of the lesion deterbefore biopsy. The distance from to lesion (3). was with a 14-gauge Biopsys Medical) 1, 1996, to the ously to con- by “targeting” pared mined were gauge vacuum-assisted localization images Probes of 85 consecutive stereotactic withand the images were in 12 lelocalization review was performed (Mammotome; deployment. stereotactic localization 14-gauge opsy probe of the ture was rotated 180#{176} and closed, probe was removed. Stereotactic of the images to the of mammograms marks cleaning clip. Needle A retrospective black illustrates in 11 lesions were reviewed. The interval from stereotactic biopsy to localization was 21 days (mean, 30 Biopsies both The clip case days; range, 10-92 days). In all 19 lesions in which surgery was performed, surgical histopathologic findings were reviewed. site. until This the in 12 patients. images median needle 4 (27)* of lesions. in the breast. stereotactic tained to confirm accurate positioning, and the clip was deployed. Stereotactic images were obtained to confirm deployment of the clip. Coordinates of the clip on the stereotactic images were compared with lesion coordinates before biopsy. Mammograms obtained immediately after stereotactic biopsy and clip placement in these 15 lesions showed a hematoma in 11 (73%). Mammograms obtained after biopsy suggested that the original mammographic lesion was completely removed in nine (60%) of 15 lesions, obscured in one (7%), and diminished in five (33%). Six lesions underwent needle localization a median of 15 days (mean, 21 days; range, Mean Range Refers in which of thorough before preoperative parentheses t Refers fragment in a case fragment. the importance z z of a tissue probe to deploy to this probe Median the the clip failed Median Mean Y * 2. retrieved x placed, wall was targeted, a 13trocar-style biopsy needle Products, Northbrook, Ill) after necessary the 11-gauge the after because probe the use of vacuum bowl of the probe. side 11-gauge clip wall biopsy placement for clip was is accomplished to pull tissue not through with into the 1 shows the distance from the clip to the lesion site on steneotactic images obtained after biopsy. The distance from the clip to the lesion site was less than 1 cm in 40 (95%) of 42 lesions in which clips were placed through the 11-gauge probe versus 11 (73%) of 15 lesions in which clips were placed after 14-gauge vacuum-assisted biopsy (P < .04). The largest errors were in the depth or z axis. No complications on untoward reactions to the clip were encountered. In two additional lesions in which stereotactic 11-gauge vacuum-assisted biopsy was performed during this period, the clip attached to fragments in the bowl of the probe and failed to deploy in the breast (Fig 2). One of these was the first case in which clip placement was attempted through the 11-gauge probe; the other occurred in the 2nd month of our experience with this clip. Needle localization images in 11 patients who had undergone clip placement after 11 -gauge stereotactic vacuum-assisted biopsy revealed hematoma at the biopsy site in four (36%) patients. These hematomas were 0.6-2.4 cm (median, 1.5 cm; mean, 1.5 cm). Needle localization images in six patients who had undergone clip placement after 14-gauge stereotactic vacuum-assisted biopsy showed no evidence of hematoma. No air was identified on images obtained during needle localization. Radiology . 419 In all 19 lesions in which surgery was performed after clip placement through the 11-gauge probe, the biopsy site was identified at histopathologic analysis of the surgical specimen (Fig 3). Correlation of stereotactic 11gauge vacuum biopsy findings and surgical histopathologic findings is shown in Table 2. There were no atypical ductal hypenplasia or ductal carcinoma in situ “underestimates” (2). In three ductal carcinoma in situ and ‘1 two atypical surgical onstrated ductal hyperplasia lesions, histopathologic analysis demno residual carcinoma or atypical ductal hyperplasia, ‘ nespec- tively, although the biopsy sites were identified. Of six lesions that underwent surgery after 14-gauge steneotactic vacuumassisted biopsy and clip placement, the biopsy site was identified at histo- ‘ a. b. pathologic analysis in five (83%) lesions (Table 3). In one patient in whom ductal carcinoma in situ was diagnosed at 14-gauge vacuum-assisted biopsy, the clip was 3 mm distant from the biopsy site on stereotactic images obtained after biopsy. Needle localization of the clip was performed, but neither the clip nor the carcinoma were removed at surgery. Subsequent neexcision yielded the clip and nevealed ductal carcinoma in situ. DISCUSSION A directional, vacuum-assisted biopsy instrument is available for performing percutaneous breast biopsy (1-5,7,8). Larger volumes of tissue are obtained with this equipment than with an automated gun for two reasons. First, the vacuum instrument enables acquisition of larger tissue specimens, with mean specimen weights of 17 mg for the automated gun and needle (5), 34 mg for the 14gauge vacuum-assisted instrument (5), and 100 mg for the 11-gauge vacuum-assisted biopsy instrument (Burbank F, oral communication, April 1997). Second, the ability of the vacuum instrument to obtain multiple samples with a single insertion and to suction blood from the biopsy site facilitates acquisition of a larger number of tissue specimens than was feasible previously (5). Because of the large volumes of tissue that may be removed with the vacuum device, the mammognaphic findings associated with the original lesion may be removed completely at vacuum-assisted biopsy. In two previously published series of 14-gauge vacuum-assisted biopsy, Burbank et al (5) and 420 Liberman Radiology #{149} et al (3) reported d. C. Figure 3. (a) Collimated mediolateral oblique mammogram in a 45-year-old woman demon- strates a cluster of pleomorphic calcifications (arrow) measuring 0.5 cm in the longest dimension. (b) Collimated mediolateral oblique mammogram obtained after stereotactic 11-gauge vacuum-assisted biopsy and clip placement demonstrates no residual calcifications. The clip is located within the biopsy cavity. Histopathologic analysis revealed ductal carcinoma in situ. (c) Collimated mediolateral oblique mammogram obtained during needle localization demonstrates the wire localizing the clip. (d) Radiograph of the specimen shows the clip. Surgical histopathologic analysis revealed ductal carcinoma in situ. complete removal of the mammographic findings in 48% and 13%, respectively, of all lesions, and in 79% and 58%, respectively, of lesions 5 mm in diameter or less. Complete removal of the mammographic lesion does not ensure complete excision of the histologic process (3). Mammographic findings after stereotactic vacuumassisted biopsy are transient and cannot be relied on to localize the biopsy site for subsequent surgical excision (3). Safe use of the vacuum biopsy instrument, therefore, necessitates the ability to place a localizing marker in proximity able subsequent to the biopsy surgical site to enexcision if necessary. Our findings show ment of the localizing that clip after placethrough an 11-gauge probe, the biopsy site was identified successfully in 100% of lesions in which surgical excision was performed. After clip placement, needle localization can be performed successfully, even if the mammognaphic findings associated with the original lesion have been removed completely. For patients who undergo mastectomy after clip placement, a radio- November 1997 been tissue Table 2 Correlation 11-gauge of Stereotactic Vacuum-assisted Biopsy Surgical Stereotactic Biopsy Benign Atypical Ductal Findings ductal carcinoma Invasive Findings Surgical Ductal from is done Carcinoma In Situ 4* 0 0 0 2 0 in situ 2 1 0 0 0 4 0 0 0 6 clip placement. the breast other patient. Both were clusters of calcifications that were 0.9 and 1 .0 cm, respectively, in the longest dimension. cavities were identified at surgery but no residual ductal carcinoma in situ was found. The biopsy and Surgical Stereotactic Findings Ductal Biopsy Invasive Carcinoma Findings Benign Atypical ductal hyperplasia Ductal car- 14-gauge ing the sitioning 14-gauge Carcinoma In Situ 0 1 0 cinoma 1 insitu Invasive carcinoma * Findings yielded from ductal 2 1 0 0 subsequent surgical carcinoma 1 excision obtained ful guide the clip been ence force is entirely the error introducer needle the of biopsy, along compression of the of force maximizes in the depth vector the direction breast. This the likelihood on z axis. of vector of Z-axis en- rons are potentially of serious consequence. In the compressed breast, as in an accordion, structures that are distant in the z axis are brought close together; when compression is re- leased, in situ. through 14-gauge structures gethen move farther small errors in the sion could translate when clip that close to- apart. Therefore, z axis in compresinto larger errors compression placed were is released. through the The 11-gauge probe is introduced in an angled or “ramped” configuration, such that the vector of force is not entirely in the direction of compression (Fig 4). Funthenmore, the operator uses vacuum to pull tissue into the bowl of the probe rather out Figure 4. Photograph shows the localizing clip and introducer inside the 11-gauge probe. Note that the clip emerges from the introducer ration tirely (Image in a sloped so that along the courtesy the vector or “ramped” of force configu- is not en- direction of compression. of Biopsys Medical.) than Volume 205 Number #{149} 2 pushing the clip into the tissue. initial experience with the clip has taught us several lessons. First, it is helpful to suction the blood out of the biopsy cavity and obtain stereotactic images after tissue acquisition is complete to ascertain whether the mammographic findings associated with the original lesion have been re- Our moved. graph can be obtained of the mastectomy specimen to assist the pathologist in identification of the biopsy site. Clip placement is more accurate through the 11-gauge probe than through the introducer needle used after 14-gauge vacuum-assisted biopsy. First, placement of the clip after merely If so, clip pniate (9). free of tissue Second, placement the fragments is appro- probe after to has be- deployed that must clip by the two be before placement, as illustrated cases in which the clip failed to deploy. Clearing of tissue fragments can usually be accomplished by performing the tap tap maneuver (3); occasionally, if clogging of the probe has underwent it of biopsy and Observed distances clip and lesion site on steneotactic images may underestimate the true distances, particularly in the depth or z axis, owing to the “accordion effect” of compression. By allowing an assessment of the location of biopsy necessitates nemovprobe from the breast and poa new needle. This reposihoning allows the possibility of patient on lesion movement, which can diminish accuracy. Second, when placing after stereo- be obtained probe removal clip placement. between the the clip standard Table 3 Correlation of Stereotactic Vacuum-assisted Biopsy Surgical Findings the clip it, as procedure, Third, should and that flush of the fore releasing compression. Finally, is prudent to obtain a mammognam * Includes one lesion yielding fibroepithelial tumor (fibroadenoma vs phyllodes tumor) at stereotactic biopsy that was proved to be a fibroadenoma at surgery, one lesion yielding lobular carcinoma in situ at stereotactic biopsy and surgery, and two lesions yielding benign ductal hyperplasia at stereotactic biopsy and benign findings at surgery. The latter two lesions were excised during mastectomy for carcinoma at a separate site in one patient and during breast-conserving therapy for carcinoma at a separate site in the t and outset tactic images clip placement ensure problem during we remove the the breast at the before Invasive Carcinoma hyperplasia carcinoma probe Findings Atypical Ductal Hyperplasia Benign and a substantial acquisition, relative to the biopsy site projections, the mammogram after biopsy for subsequent on serves as a useneedle local- ization. There are other tions of a localizing addressed in our potential clip study. applicathat were not There have reports of preliminary expeniwith magnetic resonance (MR) imaging-guided localization One limitation needle inability biopsy and needle of breast lesions (10-17). of MR imaging-guided localization procedures to document lesion because contrast is often essential at MR imaging, resected placed is the retrieval, enhancement, which for lesion detection is not observed in the specimen. If a clip at MR imaging-guided could be biopsy on localization, radiography of the surgical specimen could confirm retnieval of the clip, supporting successful retrieval of the lesion. The clip descnibed in our study is compatible with a magnet of field strength 1.5 T or less; the probe is not MR imagingcompatible, but clip placement could occur outside the magnet after placement of an MR imaging-compatible introducer (15,16). Edeiken-Monroe al (18) reported preliminary experi- ence with sonographically guided et im- plantation of metallic markers to permanently localize the tumor bed in patients with breast cancer receiving preoperative chemotherapy. In eight (42%) of 19 cases, the metallic marker was the only remaining evidence of the site of the tumor bed. A localizing clip could therefore be useful the tumor site in these women locally advanced breast cancer. Mumtaz et al (19) described neous treatment interstitial laser The role cedunes cen has placement to mark with percuta- of breast cancers photocoagulation. of percutaneous ablative in the treatment of breast not been established, but of a localizing marker Rt4nh,ft, with procanat #{149} LV)1 the tumor site could play a role in this 3. evolving technique. It may be necessary to improve on the accuracy of marker placement over that reported in our study for use 4. in guiding In summary, a localizing proximity reotactic our data demonstrate clip can be placed to the biopsy vacuum-assisted placement is more the 11-gauge probe gauge biopsy. the biopsy subsequent the ated been After site site after biopsy. mammognaphic steClip 6. excision, findings with the original lesion removed completely. 7. for even if associ- have #{149} 8. Acknowledgments: We thank Lynda T. Zingaro, RT(R)(M), and Youngduk Paik, RT(R)(M), for expert technical support and David C. Perlman, MD, for invaluable assistance. 9. References 1. Parker SH, Burbank F. A practical proach to minimally invasive Radiology 1996; 200:11-20. 2. Burbank F. Stereotactic breast Parker SH, Stavros AT, Dennis 15. 10. ap- breast biopsy of vesting with the Mammotome. 1996; 62:738-744. KaneJW, Sternheim MM. Needle North Burbank F, Parker SH, Fogarty tactic breast biopsy: improved TJ. 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SC, Schnall MD, Newman RW, Powell CM, Torosian MH, Rosato EF. MR imag- ing-guided localization and biopsy of breast lesions: initial experience. Radiology 1994; 193:97-102. Ore! SC, Schnall MD, Powell CM, et al. Staging of suspected breast cancer: effect MR imaging ology #{149} Radiology MA. Chin Brenner RJ, Shellock FG, Rothman BJ, Giuliano A. Magnetic resonance imagingguided preoperative breast localization using freehand technique. BrJ Radio! 1995; 68:1095-1098. Heinig A, Heywang-Kobrunner SH, T, et al. Needle localization of breast leslons detected with MR imaging. Radiol- biopsy. atypical ductal hyperplasia and ductal carcinoma in situ lesions: improved accuracy with directional, vacuum-assisted breast biopsy. Radiology 1997; 202:843-847. 422 Radiol and trigonometric placement, can be identified surgical 5. in accurate through than after 14clip 14. biopsy techniques. 1995; 33:1171-1186. therapy. that Liberman L, Hann LE, Dershaw DD, Morris EA, Abramson AF, Rosen PP. 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