Imaging of Breast Implant-associated Complications and Pathologic Conditions: Breast Imaging

Two-Dimensional Mammography Imaging Techniques for Screening Women with Silicone Breast Implants: A Pilot Phantom Study

This study aimed to evaluate the impact of three two-dimensional (2D) mammographic acquisition techniques on image quality and radiation dose in the presence of silicone breast implants (BIs). Then, we propose and validate a new International Atomic Energy Agency (IAEA) phantom to reproduce these techniques. Images were acquired on a single Hologic Selenia Dimensions® unit. The mammography of the left breast of a single clinical case was included. Three methods of image acquisition were identified. They were based on misused, recommended, and reference settings. In the clinical case, image criteria scoring and the signal-to-noise ratio on breast tissue (SNRBT) were determined for two 2D projections and compared between the three techniques. The phantom study first compared the reference and misused settings by varying the AEC sensor position and, second, the recommended settings with a reduced current-time product (mAs) setting that was 13% lower. The signal-difference-to-noise ratio (SDNR) and detectability indexes at 0.1 mm (d' 0.1 mm) and 0.25 mm (d' 0.25 mm) were automatically quantified using ATIA software. Average glandular dose (AGD) values were collected for each acquisition. A statistical analysis was performed using Kruskal-Wallis and corrected Dunn tests (p < 0.05). The SNRBT was 2.6 times lower and the AGD was -18% lower with the reference settings compared to the recommended settings. The SNRBT values increased by +98% with the misused compared to the recommended settings. The AGD increased by +79% with the misused settings versus the recommended settings. The median values of the reference settings were 5.8 (IQR 5.7-5.9), 1.2 (IQR 0.0), 7.0 (IQR 6.8-7.2) and 1.2 (IQR 0.0) mGy and were significantly lower than those of the misused settings (p < 0.03): 7.9 (IQR 6.1-9.7), 1.6 (IQR 1.3-1.9), 9.2 (IQR 7.5-10.9) and 2.2 (IQR 1.4-3.0) mGy for the SDNR, d' 0.1 mm, d' 0.25 mm and the AGD, respectively. A comparison of the recommended and reduced settings showed a reduction of -6.1 ± 0.6% (p = 0.83), -7.7 ± 0.0% (p = 0.18), -6.4 ± 0.6% (p = 0.19) and -13.3 ± 1.1% (p = 0.53) for the SDNR, d' 0.1 mm, d' 0.25 mm and the AGD, respectively. This study showed that the IAEA phantom could be used to reproduce the three techniques for acquiring 2D mammography images in the presence of breast implants for raising awareness and for educational purposes. It could also be used to evaluate and optimize the manufacturer's recommended settings.

Challenges in Interpretation of US Breast Findings in the Emergency Setting

Emergencies in breast imaging are infrequent but not rare. Although infectious conditions such as mastitis and breast abscess are the most common breast diseases encountered in acute care settings, other entities that may require additional imaging or different treatment approaches are also seen and include traumatic injury and breast cancer. While mammography is widely available for breast evaluation in outpatient facilities, most emergency departments do not have mammography units. This makes evaluation of patients with breast disease incomplete in the acute care setting and emphasizes the role of appropriate US techniques for interpretation. It also highlights the importance of effective sonographer-to-radiologist communication to ensure patient safety and diagnostic accuracy, especially in an era of increasing adoption of teleradiology. The authors discuss the challenges in image acquisition and remote interpretation that are commonly faced by radiologists when they assess breast anomalies in the emergency setting. They present strategies to overcome these challenges by describing techniques for proper US evaluation, highlighting the importance of sonographer-radiologist communication, defining the goals of the evaluation, reviewing common differential diagnoses, and providing appropriate follow-up recommendations. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Understanding Silicone Breast Implant-Associated Complications for Radiologists

미용적 성형 및 유방암 수술 후 재건의 목적으로 사용되는 실리콘 보형물의 사용이 국내외에서 크게 증가함에 따라 진료 영역에서 실리콘 보형물 삽입술을 받은 환자들을 어렵지 않게 접하게 되었다. 기존에 알려져 있던 보형물의 파열이나 구축과 같은 합병증 외에 최근에는 유방 보형물 연관 역형성 대세포 림프종과 같은 악성 종양과의 연관성도 보고되면서 보형물 관련한 영상 검사가 증가하고 있다. 이러한 상황에서 영상의학과 의사들은 보형물 삽입술을 받은 환자에 대해 어떤 검사가 필요하고 어떤 영상 소견이 보형물 관련 합병증을 시사하는지에 관한 충분한 지식을 갖추고 있어야 할 것이다. 본 종설에서는 영상의학과 의사들이 알아야 하는 실리콘 보형물의 다양한 합병증과 이들의 영상 소견에 대해 다루고자 한다.

Imaging of breast implant and implant-associated complications: Capsular contracture and intra- or extracapsular rupture

BACKGROUND

In recent years, follow-up after breast reconstruction with silicone implants and the detection of complications have been relieved by the possibility of improved diagnostic methods.

METHODS

Between January 2015 and December 2019 a total of 40 patients (29-84 years) with silicone implants were included in this retrospective study. The implants were examined clinically and with modern imaging: general ultrasound imaging (US), magnetic resonance imaging (MRI), high resolution computed tomography (CT) and positron emission tomography -computed tomography (PET-CT). If necessary, a histological/cytological sample was taken. The breast implants were assessed by three radiologists specialized in breast imaging. The grade of capsular contracture was classified according to the Baker classification.

RESULTS

All 40 women obtained a clinical examination and an US diagnostic to identify early and more common complications such as implant folding and capsular fibrosis. Depending on the clinical examination and ultrasound findings additional MRI (n = 10), CT (n = 9) and/or PET-CT (n = 2) were performed. 16 patients had implants folding proven with US (n = 16), MRI (n = 6) and CT (n = 1). The grade of capsular fibrosis was determined according to the Baker classification. The following results were obtained in our study: 25 breast implants with Baker grade I and eleven breast implants with Baker grade II, both proven with US; one breast implants with Baker grade III and one breast implant with Baker grade IV, proven with US (n = 2), MRI (n = 1) and CT (n = 1). One patient had intracapsular rupture and one patient had extracapsular rupture, both detected on CT and surgically proven. No patient had a silicone accumulation in the lymph nodes. One patient had pathologically enlarged axillary lymph nodes, which were evaluated as inflammatory changes in PET-CT. Long-term complications such as the development of malignant breast tumors could not be observed.

CONCLUSION

To detect early complications after breast implant surgery, a regular clinical examination is indispensable. Imaging methods complement each other and if they are used multimodal, it is easier to identify early complications. Modern diagnostic modalities like ultrasound and magnetic resonance imaging expand the spectrum and improve diagnostic safety.

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.