Imaging in patients with breast implants-results of the First International Breast (Implant) Conference 2009

MRI for Evaluation of Complications of Breast Augmentation

Breast augmentation is one of the most common aesthetic procedures performed in the United States. Several techniques of breast augmentation have been developed, including the implantation of breast prostheses and the injection of autologous fat and other materials. The most common method of breast augmentation is to implant a prosthesis. There are different types of breast implants that vary in shape, composition, and the number of lumina. The rupture of breast implants is the leading cause of implant removal. The rupture rate increases substantially with the increasing age of the implant. Most implant ruptures are asymptomatic. Implant complications can be grouped into two categories: local complications in the breast and adjacent soft tissue, and systemic complications associated with rheumatologic or neurologic symptoms. The onset of local complications may be early (infection and periprosthetic collections including seromas, hematomas, or abscesses) or late (capsular contraction, implant rupture, gel bleed, or breast implant-associated anaplastic large cell lymphoma). Although mammography is the imaging modality for breast cancer screening, noncontrast breast MRI is the imaging modality of choice for evaluation of the integrity of breast implants and the complications of breast augmentation, for equivocal findings at conventional imaging, and as a supplement to mammography in patients with free injectable materials. The fifth edition of the Breast Imaging Reporting and Data System (BI-RADS) provides a systematic outline for MRI evaluation of patients with breast implants. Silicone- and water-selective sequences provide useful supplemental information to confirm intracapsular and extracapsular rupture. Breast MRI for evaluation of implant integrity does not require intravenous contrast material. The use of MRI contrast material in patients with breast augmentation is indicated when infection or malignancy is suspected. Radiologists should have a thorough understanding of the different techniques for breast augmentation, normal imaging features, and complications specific to breast augmentation. An invited commentary by Ojeda-Fournier is available online. ^©RSNA, 2022.

A Surgeon's Empirical Perspectives on Use of High-resolution Ultrasound in Preoperatively Detecting a Rupture in the Context of Breast Implant Crisis in Korea

BACKGROUND

We previously proposed a novel method for detecting a rupture of a breast implant using high-resolution ultrasound (HRUS). We therefore conducted this retrospective, observational study to describe its feasibility in making a preoperative diagnosis of rupture of the device in patients receiving an implant-based augmentation mammaplasty.

METHODS

We initially evaluated the medical records of the patients who had received primary or secondary augmentation mammaplasty using a breast implant at other hospitals for aesthetic or reconstructive purposes between August 31, 2017, and August 31, 2020. The patients underwent breast US using the Aplio i600 (Canon Medical System, Otawara, Tochigi, Japan) system with a 7-18 MHz linear transducer. Through a retrospective review of the patients' medical records, we analyzed their baseline and clinical characteristics. Then, we compared an agreement between preoperative diagnosis of rupture on HRUS and findings at reoperation.

RESULTS

A total of 29 patients with rupture (55 breasts) were evaluated for the performance of ultrasound in making a diagnosis of rupture. This showed that they were unaware of rupture but they were diagnosed with it on ultrasound. Preoperatively, there were no cases of rupture in 110 left breasts (80.9%) and 107 right breasts (78.7%), which exactly matched to the number of breasts without rupture on HRUS. Moreover, preoperatively, there were 26 (19.1%) and 29 cases (21.3%) of rupture in the left and right breast, respectively, which exactly matched to the number of breasts with rupture on HRUS.

CONCLUSIONS

In conclusion, patients who are suspected of having rupture of a breast implant should be stringently evaluated for presence of rupture and, if any, its scope using HRUS. Moreover, we propose that surgeons consider using HRUS in making a preoperative diagnosis of rupture of a breast implant.

LEVEL OF EVIDENCE III

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Consensus about image quality assessment criteria of breast implants mammography using Delphi method with radiographers and radiologists

Aims

To identify image quality criteria that can be applied to assess breast implant (BI) mammograms according to radiologists and radiographers’ perspectives and to explore the level of agreement about criteria priority.

Methods

A two-round Delphi method using a questionnaire was applied to identify the level of agreement between experts, asking them to rank each image criteria available for mammography according to 4 possible answers (1 = need to have, 2 = nice to have, 3 = not pertinent/appropriate, 4 = do not know). Criteria for craniocaudal (CC), mediolateral-oblique (MLO) and lateral (ML), with and without Eklund manoeuvre, were included. This process was repeated after removing the less relevant criteria.

Results

Between first and second rounds, different results were obtained regarding the criteria to assess CC and MLO images. Details for anatomic areas were considered the most relevant by radiographers during the first round, while general criteria were prioritised during the second round. Radiologists focused more on analysis of the spread of the breast tissue, if the breast was aligned with detector’s centre and level of contrast. The analysis of implant flow, the BI anterior edge and the maximum retropulsion of BI when Eklund manoeuvre is performed were the specific aspects of BI imaging considered as relevant for assessment.

Conclusions

The importance of each criterion used to assess BI mammograms was not the same between radiographers and radiologists, suggesting the two groups of experts are looking for different requirements from the image. Further education and training is necessary to align strategies for assessing BI mammograms, and some criteria need to be adapted to reduce subjectivity.

Study of breast implants mammography examinations for identification of suitable image quality criteria

PURPOSE

To characterise the mammography technique used in breast cancer screening programmes for breast implants (BI) and to identify if the image quality (IQ) criteria available in literature are applicable to BI imaging.

METHODS

The study was conducted in two phases: literature review to find IQ criteria used in mammography combining keywords in several sources; and assessment of 1207 BI mammograms using the criteria that was identified previously to see if they were achieved or not. An observation grid was used to collect information about positioning, beam energy, compression force, and exposure mode. Descriptive statistics and Student's t test and χ2 test were performed according to the nature of the variables.

RESULTS

Forty-seven out of 2188 documents were included in the analysis, with 13 items identified to assess the quality of positioning, 4 for sharpness, 3 for artefacts, and 2 for exposure parameters. After applying the criteria to BI mammograms, retroglandular fat was not included in 37.3% of the images. The "Pectoral-Nipple-Line" criterion was achieved in 35% of MLO/ML images. The placement of the implant (subpectoral/subglandular) or performing the Eklund had significant influence on the visible anatomy (p = < 0.005), alongside whether the breast was aligned to the detector's centre.

CONCLUSIONS

Some of the criteria used to assess standard mammograms were not applicable to BI due to implant overlap. The alignment of the image with the detector's centre seems to have an impact on the amount of visible tissue. Further studies are necessary to define the appropriate protocol, technique, and suitable quality criteria to assess BI mammograms.

Removing silicone artifacts in diffusion-weighted breast MRI by means of shift-resolved spatiotemporally encoding

PURPOSE

Evaluate the usefulness of diffusion-weighted spatiotemporally encoded (SPEN) methods to obtain apparent diffusion coefficient (ADC) maps of fibroglandular human breast tissue, in the presence of silicone implants.

METHODS

Seven healthy volunteers with breast augmentation were scanned at 3 Tesla (T) using customized SPEN sequences yielding separate silicone and water (1) H images in one scan, together with their corresponding diffusion-weightings.

RESULTS

SPEN's ability to deliver multiple spectrally resolved images in a single scan, coupled to the method's substantial robustness to magnetic field heterogeneities, served to acquire ADC maps that could be freed from contributions that did not belong to fibroglandular tissue.

CONCLUSION

SPEN-based sequences incorporating spectral discrimination and diffusion-weighting enable the acquisition of reliable ADC maps despite the presence of dominant signals from silicone implants, thereby opening new screening possibilities for the identification of malignancies in breast augmented patients.

Role of US in evaluating breast implant integrity

PURPOSE

To assess the diagnostic accuracy and inter-observer variability of ultrasound (US) in recognizing signs of intra or extra-capsular rupture of silicone breast implants by using the magnetic resonance imaging (MRI) findings as the reference standard.

METHODS

150 patients for a total of 300 implants underwent breast US and subsequently MR examination searching for signs of intra or extra-capsular rupture. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy were calculated for breast US having MRI findings as the reference standard. Cohen's kappa statistics was used in order to assess inter-observer agreement for US.

RESULTS

170/300 (57 %) implant ruptures were detected at US (intra-capsular n = 110, extra-capsular n = 60). By comparing US findings with MR results, overall sensitivity, specificity, accuracy, PPV, and NPV of 79, 63, 70, 65, and 77 %, respectively, were found for breast US. In case of intra-capsular rupture, sensitivity, specificity, accuracy, PPV, and NPV of 63, 63, 63, 45, and 77 %, respectively, were obtained; 100 % values were found for extra-capsular rupture US diagnosis.

CONCLUSION

US can be used as the first examination in patients with breast implants. US intra-capsular rupture detection requires further evaluation by MRI; in case of extra-capsular rupture US diagnosis, surgical implant removal could be proposed without further investigations.

Imaging of breast implants-a pictorial review

The number of women with breast implants is increasing. Radiologists must be familiar with the normal and abnormal findings of common implants. Implant rupture is a well-known complication after surgery and is the main cause of implant removal. Although mammography and ultrasonography are the standard first steps in the diagnostic workup, magnetic resonance imaging (MRI) is the most useful imaging modality for the characterisation of breast implants because of its high spatial resolution and contrast between implants and soft tissues and absence of ionising radiation. MRI has the highest sensitivity and specificity for implant rupture, thanks to its sequences that can suppress or emphasise the signal from silicone. Regardless of the technique used, the overall aim of imaging breast implants is to provide essential information about tissue and prosthesis integrity, detect implant abnormalities and detect breast diseases unrelated to implants, such as breast cancer.