Brought to you by
ECR 2019 / C-1559
Location of non-palpable breast lesions with magnetic seeds, description of the technique
Congress: ECR 2019
Poster No.: C-1559
Type: Educational Exhibit
Keywords: Cancer, Localisation, Ultrasound, Mammography, Ultrasound physics, Breast
Authors: N. I. Vega de Andrea, D. Del Hoyo Pastor, B. Leyes Segura, A. Torrecillas Ors; Palamos/ES

Findings and procedure details

The insertion of seeds is carried out through two different imaging techniques, as follows. 


Ultrasound-guided seed insertion


We use a Canon medical ultrasound, model Aplio a450. We emphasize that one of the advantages of Endomag needles is their high echogenicity, which eases the visualization of the very needle, as well as the ultrasound procedure itself.


  • The patient is prepared, the procedure explained, and the material for marking is prepared. Fig. 3

  • The radiologist localizes the lesion and inserts the needle in real-time. Fig. 4

  • Once the lesion is localized by ultrasound and the point of the needle is placed in the required direction, the safety lock is withdrawn and the embolus pushed.

  • The correct location of the seed is confirmed by mammography and the excision of the affected tissue can then be carried out.  Fig. 5

Seed insertion guided by stereotaxy with mammography



We use a direct digital mammograph by Hologic® with its Affirm® stereotaxy system, with which we carry out vacuum-guided stereotaxy. Our team was the first in Spain to use the Affirm® system alongside Magseed® magnetic seeds for localizing non-palpable lesions.  Fig. 6


  • The patient is programmed for mamography and the stereotaxy system is calibrated.  Fig. 7

  • The patient is prepared, the procedure is explained and material for marking is prepared.   Fig. 8

  • The affected breast is placed in the mammography unit's detector, and using a compression plate with an aperture, the area containing the lesion is localized, with help from previous mammograms.   Fig. 9

  • The first craniocaudal view is taken, to confirm the location of the lesion.

  • If the area is that indicated, two stereotactic projections are made at +15° and -15°. 

  • Correct visualization of the lesion is ensured through the craniocaudal view and two stereotactic views. The affected area where the needle shall be inserted is marked as visualized on the mammograph screen.   Fig. 10

  • Once the site where the seed will be inserted is marked, the coordinates are sent to the stereotaxy system in order to insert the needle in the direction of the lesion. The Endomag 18G 12cm needle is selected.  Fig. 11

  • The stereotaxy system is guided toward the lesion from the viewer until the coordinates become X0 Y0 and Z0. If these zero values aren't obtained, they are corrected for on advancing the point of the needle into the lesion.  Fig. 12

  • The needle guides are inserted, local anaesthetic is administered to the area of approach and an incision mark is made in the skin with a scalpel blade to permit entry.  Fig. 13

  • Pressure is maintained on the needle with the guides and it is inserted manually until the coordinates in the viewer become X0, Y0 and Z0, which indicates that the point at which the seed is to be inserted has been reached.  Fig. 14

  • A Pre-Fire projection may be taken to confirm that the needle's point is directed at the lesion.  Fig. 15

  • If it is the desired location, the needle's safety lock is removed and the embolus pushed thus inserting the seed.  Fig. 16

  • The needle and compressionplate are withdrawn, and the scalpel incision is dressed.

Once the seed is inserted, independent of the technique employed, it is checked by mammography through lateral and craniocaudal projections.  Fig. 17


The radiologist certifies that the seed is correctly inserted, emits his report accordingly, and the surgical team can procede to program the date for excision of the affected tissue. The mammographic confirmation of the specimen is performed on the day of surgery.  Fig. 18


During the period studied (December 2017 - December 2018) we marked 36 patients with Magseed® magnetic seeds. On two occasions the insertion of two markers was necessary. 25 patients had proceeded from the screening program while 12 came from the diagnostic mammography program.

Localized impalpable lesions were distributed as follows: 13 nodules, 9 assymetries, 3 distorsions, 9 microcalcifications and 2 neoadjuvancies  Fig. 19. The diagnosis of these lesions was made by ultrasound in 25 cases, and by stereotaxy in 12 cases. The magnetic marker was inserted in 32 cases through ultrasound and in 4 cases through stereotaxy.


Ultrasound was used in the greater number of cases for insertion of the magnetic marker because it was observed that after stereotaxy a small hematoma remained, which was used as a reference to locate the impalpable lesion.  Fig. 20



POSTER ACTIONS Add bookmark Contact presenter Send to a friend Download pdf
2 clicks for more privacy: On the first click the button will be activated and you can then share the poster with a second click.

This website uses cookies. Learn more