16.4 Breast Augmentation and Implanted Devices

Augmentation and devices as variance, not as a second Eklund course

Procedures 2.B lists implanted devices (pacemaker, port) and breast augmentation (implants, injections) next to the habitus and postsurgical items. A separate chapter covers the full implant-displaced (ID / Eklund) method. This section applies that method as a variance decision: do ID when tissue can be displaced; change the plan when it cannot; and treat hardware in the chest wall as a geometry and automatic exposure control (AEC) problem.

Quick Answer: If you can pull native tissue forward, take ID views. If you cannot — contracture, free silicone, a device in the way — document the limit, include every possible remnant of breast, and do not expose AEC through metal.

Ask every patient about implants, injections, fat grafting, ports, pacemakers, and loop recorders. Look at the chest before the gown is fully closed. A subclavicular bulge is a generator until proven otherwise.

Implants: in-place views plus ID when tissue moves

Cosmetic or reconstructive implants may be saline or silicone and subglandular (in front of pectoralis) or subpectoral (behind the muscle). Implants are not a contraindication to mammography. They do obscure tissue on standard views, which is why a complete implant screening study is not two images per breast.

Implant-in-place views

Obtain CC and MLO with the implant in the field, using only enough compression to immobilize. You are not trying to flatten the implant. These views show implant contour, a portion of posterior tissue, and — on MLO — the relationship to pectoralis that tells the radiologist whether the pocket is subglandular or subpectoral.

Implant-displaced views when tissue can be displaced

If native tissue will slide, perform ID views: walk the implant back against the chest wall with your fingers, pull the anterior breast forward, and compress tissue only. Subpectoral and mobile implants displace more readily. Capsular contracture (a tight fibrous capsule, Baker clinical hardening) may make the implant immovable. If the implant will not displace, do not force it. Forcing a contracted implant is how ruptures and patient refusals happen. Document “implant not displaced — capsular contracture,” include as much anterior tissue as the in-place views allow, and follow facility protocol for extra views such as a true lateral. ID is not optional when displacement is possible, and it is not mandatory theater when displacement is impossible.

When both pairs are possible, each breast typically receives four images (CC and MLO in-place plus CC and MLO ID). That is the variance application of Eklund — not a retelling of every hand position in the dedicated implant chapter. If the ID paddle is sampling only a thin sliver of tissue, confirm that the AEC region is over breast, not over residual implant; otherwise use manual technique.

Fat grafting and some hybrid augmentations may not have a discrete implant to push back. Image the breast as tissue, mark scars, and do not invent an ID pull for a graft that has already been incorporated.

Injections: silicone that will not displace

Free silicone injections (and some other illicit fillers) are a different examination from encapsulated implants. Mammography shows multiple extremely dense nodules, often with rim or bizarre calcification from granulomas. The silicone is distributed through parenchyma and lymphatics. There is no implant to walk back, so ID technique does not apply. Attempts to “displace” injected silicone only smear dense droplets and hurt the patient.

Say so on the history sheet: silicone injections — tissue not displaceable — mammography limited. Extra standard views still help at the periphery. Ultrasound and MRI are often required for cancer detection in this setting; your mammogram remains part of the workup when ordered, with honest technical limitations. Do not tell the patient that eight ID images will “clear” injected breasts. They will not.

Pacemaker, ICD, and port

A pacemaker or implantable cardioverter-defibrillator (ICD) generator usually sits in the upper chest, often on the left, with leads running toward the heart. A port (port-a-cath) sits in a similar pocket with a reservoir you can palpate. Any of these can hide a strip of breast or axillary tissue and can fool AEC.

Rotate, include breast, protect the pocket

Rotate the patient and, if needed, the C-arm so the device sits at the edge of the field rather than in the middle of the breast. Include as much breast tissue as possible around the generator. An extra CC or a spot of the tissue immediately adjacent to the device is appropriate when the in-place image still excludes a strip of parenchyma. Do not park the device in the center of a pretty, incomplete breast.

Do not crush the generator, leads, or reservoir. Compression on the breast inferior and medial to the pocket is fine; compression that pits the paddle into a recently placed device is not. Newly implanted hardware may need a healing delay defined by the implanting clinician — days to weeks, not an invented year-long ban. Ask. Document if the order proceeds with limited compression over a fresh pocket.

Manual technique if the device is over AEC

If the pacemaker, ICD, or port overlies the AEC sampling region, the system will try to penetrate metal. That typically overexposes the patient or, depending on the algorithm, underexposes breast tissue next to a bright generator. Move the sampling region over breast if the unit allows it. If the device still dominates the sampled area, switch to manual technique using comparable thickness and composition from the other breast or from a prior exam. The same rule applies to a residual implant sitting over AEC on an attempted ID view.

Ports used for chemotherapy belong in the history for another reason: the patient may have fragile irradiated or postsurgical tissue on the same side (see 16.2). Combine the rules — do not force painful tissue, and do not compress the reservoir.

Exam traps

Do not skip ID views on a mobile implant because “digital can see through silicone.” In-place views still hide anterior tissue that ID is meant to show. Do not perform theatrical ID pulls on free silicone or on a rock-hard contracted capsule. Do not center a pacemaker in the field so the breast looks symmetrical with the other side. Do not leave AEC on auto when the sampled region is a metal can. Do not treat a port as irrelevant hardware; it is an implanted device on the same 2.B list as the pacemaker, and it costs posterior and axillary tissue if you ignore it.