Ch 13 Breast Implants Flashcards
What are the 2 m/c types of breast implants?
Saline + silicone
What imaging modality is the gold standard for assessing implant integrity?
MRI
Why is u/s used to evaluate breast implants?
-It evaluates the overlying breast tissues for pathology + changes within/around the prosthesis
-U/s has a lower cost
Is mammography used to evaluate breast implants?
No, it may be suboptimal + difficult to assess
Where are implants m/c placed?
-Posterior to glandular tissue + anterior to pectoralis muscle
-In the subglandular or prepectoral location
What is another less common location implants can be placed?
-Posterior to the pectoralis major muscle
-In the submuscular or retropectoral location
(this may reduce capsular contracture)
What location is standard for placement of tissue expanders + implants following a mastectomy?
Posterior to the pectoralis major muscle (submuscular or retropectoral location)
SF of saline implants?
Single anechoic lumen + an anterior filling port to allow fluid expansion to the desired size
(note: the fill valve may be the cause of a palpable lump near the areola)
Are single or double lumen silicone implants m/c?
Single
SF of single lumen silicone implants?
-Generally anechoic
-They come in prefilled sizes
SF of double lumen silicone implants?
-They have separate silicone + saline chambers
-An echogenic membrane is shown to separate the chambers
-A filling port extends to the expandable saline chamber
Are fibrous capsules more pronounced with silicone or saline implants?
Silicone
Why does a fibrous capsule form around an implant?
It is the bodies response to a foreign body
SF of silicone shells?
Smooth or textured (texturing may reduce capsular contracture)
SF of normal implants?
-Capsule shell echo complex (3 echogenic lines)
-Textured implants appear thick or fuzzy
-Reverb artifact (band of false echoes across anterior lumen of implant)
-Propagation speed artifact in silicone implants (posterior wall of implant + distal structures falsely appear deeper into the chest than the adjacent tissues)
What is the capsule-shell-echo-complex?
-Smooth shells consist of an inner + outer layer
-It appears as 2 smooth thin echogenic lines with an adjacent capsule
-These 3 close echogenic lines is called the capsule-shell-echo-complex
Propagation speed artifact occurs in silicone or saline implants?
Silicone - b/c the speed of sound is much slower
List 4 common u/s findings when imaging breast implants?
-Linear in folding of the shell
-Long/wavy folds can mimic a double lumen implant or a intracapsular rupture
-Lobulation of the contour of an intact implant or wrinkling
-Reactive fluid may be b/w the shell + fibrous capsule (aka peri-implant effusion)
Changes in implant shape, contour + size may be due to what?
-Fibrous or calcific contracture
-Herniation
-Rupture
-Deflation
List 3 main implant complications?
-Capsular contracture (m/c with silicone implants)
-Focal herniation
-Peri implant seroma abscess or hematoma
Capsular contracture is m/c with silicone or saline implants?
Silicone
What is capsular contracture?
-Thickening + hardening of the fibrous capsule
-The implant becomes round, hard + immobile
SF of capsular contracture?
-Thickened capsule-shell complex with poor compressibility when probe pressure is applied
-Capsular calcifications may be seen
What is a focal herniation caused by?
-Herniation of the implant that occurs through a crack in the fibrous capsule
-It presents as a palpable lump
What is a peri-implant seroma abscess or hematoma caused by?
From implant surgery, infection or trauma
Why would implants rupture spontaneously?
Due to trauma or degeneration over time (increased age of implant)
What 2 imaging modalities are most sensitive when assessing silicone implants integrity?
MRI + u/s
(b/c silicone blocks the penetration of x-rays, saline does not)
Do saline or silicone implants rupture more easily from trauma?
Saline
(saline is reabsorbed by the body after the rupture, whereas silicone is not)
Silicone implant failure is classified as an ___ or ___?
Intracapsular rupture (ICR) or extracapsular rupture (ECR)
What is the m/c type of implant rupture?
ICR
What is an ICR?
Break in the implant shell but is still contained by the fibrous capsule
SF of an ICR?
Classic appearance:
-Step ladder sign or parallel line sign
-Appears as multiple, parallel echogenic lines layered within the silicone gel contained by the fibrous capsule
The step ladder sign is associated with ___?
Significant rupture
The step ladder sign corresponds to the ___ sign seen on MRI scans?
The linguine sign
What are the pitfalls when trying to diagnose ICR?
Confusing other linear echoes as ICR (ex. reverb, redundant radial folds or double lumen membrane interfaces)
Which imaging modality is more reliable than u/s in diagnosing ICR?
Non-contrast MRI
(especially in pt’s with double lumen implants)
What is an ECR?
-Defect in both the implant shell + fibrous capsule
-Silicone leaks into the breast tissue
-Free silicone can migrate along the chest wall to the axilla, lymph nodes + extramammary sites
SF of an ECR?
Echogenic noise sign or snowstorm appearance
