MR imaging of the reconstructed breast: What the radiologist needs to know

Acellular Dermal Matrix: Imaging Features With Histopathology Correlation

Acellular dermal matrix (ADM) is an immunologically inert graft, typically from cadaveric skin, often used in postmastectomy breast reconstruction. Created from decellularized dermal tissues that have been treated to remove DNA and antigenic donor cells (leaving extracellular matrix), ADM is often used as a structural scaffold or sling to reinforce and support the structure and position of a breast implant during postoperative integration in implant-based breast reconstruction; ADM can also be used to fill cosmetic defects. Advantages of ADM use include improved cosmesis and reduced capsular contracture rates. On US, ADM can be seen as a subtle band with variable echogenicity adjacent to the implant. When folded on itself or redundant, ADM may present as a palpable oval mass with indistinct or circumscribed margins and variable echogenicity. On mammography, ADM can be seen as a circumscribed oval equal density mass when redundant and folded on itself; a layered appearance may be evident on tomosynthesis. On MRI, presence and absence of enhancement have been documented. Imaging findings likely vary depending on the degree of host tissue remodeling and incorporation, and when biopsied, histopathologically, ADM may be difficult to distinguish from scarring. Successful imaging diagnosis of ADM is aided by clinical knowledge of the intraoperative use and configuration of ADM, which may help differentiate ADM from new or recurrent malignancy and avoid unnecessary biopsy.

Multimodality Imaging of Postmastectomy Breast Reconstruction Techniques, Complications, and Tumor Recurrence

For women undergoing mastectomy, breast reconstruction can be performed by using implants or autologous tissue flaps. Mastectomy options include skin- and nipple-sparing techniques. Implant-based reconstruction can be performed with saline or silicone implants. Various autologous pedicled or free tissue flap reconstruction methods based on different tissue donor sites are available. The aesthetic outcomes of implant- and flap-based reconstructions can be improved with oncoplastic surgery, including autologous fat graft placement and nipple-areolar complex reconstruction. The authors provide an update on recent advances in implant reconstruction techniques and contemporary expanded options for autologous tissue flap reconstruction as it relates to imaging modalities. As breast cancer screening is not routinely performed in this clinical setting, tumor recurrence after mastectomy and reconstruction is often detected by palpation at physical examination. Most local recurrences occur within the skin and subcutaneous tissue. Diagnostic breast imaging continues to have a critical role in confirmation of disease recurrence. Knowledge of the spectrum of benign and abnormal imaging appearances in the reconstructed breast is important for postoperative evaluation of patients, including recognition of early and late postsurgical complications and breast cancer recurrence. The authors provide an overview of multimodality imaging of the postmastectomy reconstructed breast, as well as an update on screening guidelines and recommendations for this unique patient population. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Acellular dermal matrix imaging features in breast reconstructive surgery: a pictorial review

Acellular dermal matrices (ADMs) are biological engineered tissues, which may provide an immunologically inert scaffold in breast reconstruction. Since the literature on imaging features of ADMs is limited, radiologists must be aware of the common imaging appearances of ADM, to differentiate normal conformation from residual or recurrent disease. Our purpose is to review the current role of ADMs in implant-based breast reconstruction, describing the normal imaging findings at ultrasound, mammography, and MRI also considering the possible changes over time. In this pictorial essay, we reviewed imaging features of ADMs described in the literature and we reported our experience in patients who underwent reconstructive surgery with human or animal ADM for newly diagnosed breast cancer.

Imaging findings after a total reconstructed breast with autologous fat transfer: what the radiologist needs to know

Autologous fat transfer (AFT) is an upcoming technique for total breast reconstruction. Consequently, radiological imaging of women with an AFT reconstructed breast will increase in the coming years, yet radiological experience and evidence after AFT is limited.

The surgical procedure of AFT and follow-up with imaging modalities including mammography (MG), ultrasound (US), and MRI in patients with a total breast reconstruction with AFT are summarized to illustrate the radiological normal and suspicious findings for malignancy.

Imaging after a total breast reconstruction with AFT appears to be based mostly on benign imaging findings with an overall low biopsy rate. As higher volumes are injected in this technique, the risk for the onset of fat necrosis increases. Imaging findings most often are related to fat necrosis after AFT. On MG, fat necrosis can mostly be seen as oil cysts. The occurrence of a breast seroma after total breast reconstruction with AFT is an unfavourable outcome and may require special treatment. Fat deposition in the pectoral muscle is a previously unknown, but benign entity. Although fat necrosis is a benign entity, it can mimic breast cancer (recurrence).

In symptomatic women after total breast reconstruction with AFT, MG and US can be considered as first diagnostic modalities. Breast MRI can be used as a problem-solving tool during later stage. Future studies should investigate the most optimal follow-up strategy, including different imaging modalities, in patients treated with AFT for total breast reconstruction.

Imaging of the Reconstructed Breast

The incidence of breast cancer and, therefore, the need for breast reconstruction are expected to increase. The many reconstructive options available and the changing aspects of the field make this a complex area of plastic surgery, requiring knowledge and expertise. Two major types of breast reconstruction can be distinguished: breast implants and autologous flaps. Both present advantages and disadvantages. Autologous fat grafting is also commonly used. MRI is the modality of choice for evaluating breast reconstruction. Knowledge of the type of reconstruction is preferable to provide the maximum amount of pertinent information and avoid false positives. Early complications include seroma, hematoma, and infection. Late complications depend on the type of reconstruction. Implant rupture and implant capsular contracture are frequently encountered. Depending on the implant type, specific MRI signs can be depicted. In the case of myocutaneous flap, fat necrosis, fibrosis, and vascular compromise represent the most common complications. Late cancer recurrence is much less common. Rarely reported late complications include breast-implant-associated large cell anaplastic lymphoma (BIA-ALCL) and, recently described and even rarer, breast-implant-associated squamous cell carcinoma (BIA-SCC). In this review article, the various types of breast reconstruction will be presented, with emphasis on pertinent imaging findings and complications.

Beyond the abdominal and pelvic cavity: abdominal wall and spinal "Aunt Minnies"

Abdominal wall and spinal soft tissue findings are frequently encountered on CT or MR imaging of the abdomen and pelvis. Many of these entities have specific imaging findings, for which a definitive diagnosis can be made without the need for further work up. These abdominal wall and spinal findings may be diagnostically challenging for sub-specialized abdominal radiologists who are unfamiliar with their appearance and appropriate management. This review article describes and illustrates pathognomonic or characteristic abdominal wall and spinal pathologies, which reside outside the abdominopelvic cavity. The cases selected all have findings that allow a confident diagnosis without further imaging or intervention. The cases presented include myonecrosis, intramuscular abscess, myositis, iliopsoas bursitis, Morel-Lavallée lesion, hydrocele of canal of Nuck, Klippel Trenaunay Weber syndrome, neurofibroma with target sign, perineural cysts, filum terminale lipoma, calvarial bone flap, transverse rectus abdominis muscle (TRAM) flap, liposuction, and hidradenitis suppurativa, among others. Although not all-encompassing, this paper will help abdominal radiologists to accurately diagnose a variety of abdominal and pelvic extra-cavitary soft tissue pathologies by identifying key radiologic findings.

Breast MRI: an illustration of benign findings

Despite its unparalleled sensitivity for aggressive breast cancer, breast MRI continually excites criticism for a specificity that lags behind that of modern mammographic techniques. Radiologists reporting breast MRI need to recognise the range of benign appearances on breast MRI to avoid unnecessary biopsy. This review summarises the reported diagnostic accuracy of breast MRI with particular attention to the technique's specificity, provides a referenced reporting strategy and discusses factors that compromise diagnostic confidence. We then present a pictorial review of benign findings on breast MRI. Enhancing radiological skills to discriminate malignant from benign findings will minimise false positive biopsies, enabling optimal use of multiparametric breast MRI for the benefit of screening clients and breast cancer patients.

Diagnosis and management of breast implant capsule recurrence following mastectomy and subpectoral implant - innovative use of ADM for reconstruction

It is well reported that patients who have undergone breast augmentation and subsequently develop breast cancer can successfully undergo breast-conserving therapy with preservation of their implants. However, there is a paucity of literature on the radiological investigations and surgical techniques in postmastectomy implant-reconstructed patients who develop recurrences to enable preservation of their implant-based reconstruction whilst effectively treating the local recurrence. The wide adoption of acellular dermal matrix use in prosthetic breast reconstruction in recent years has made radiological evaluation of such patients challenging. Herein presented is a case of a 37-year-old woman where wide local excision of a local recurrence abutting a peri-implant capsule following previous mastectomy and implant-acellular dermal matrix (ADM) reconstruction was performed with successful preservation of reconstruction volume (and shape) using an ADM patch to repair the capsular defect whilst retaining the implant in situ. Radiological investigation facilitated and guided the surgical planning and oncological clearance.

Nipple-sparing Mastectomy: What the Radiologist Should Know

Nipple-sparing mastectomy (NSM) is increasingly offered to patients undergoing treatment of breast cancer and prophylaxis treatment for reduction of breast cancer risk. NSM is considered oncologically safe for appropriately selected patients and is associated with improved cosmetic outcomes and quality of life. Accepted indications for NSM have expanded in recent years, and currently only inflammatory breast cancer or malignancy involving the nipple is considered an absolute contraindication. Neoplasms close to and involving the nipple areolar complex are common, and cancer of the lactiferous ducts can spread to the nipple. Therefore, accurate determination of nipple involvement at imaging examinations is critical to identifying appropriate candidates for NSM and preventing local recurrence. Multiple imaging features have been described as predictors of nipple involvement, with tumor to nipple distance, enhancement between the index malignancy and the nipple, and nipple retraction demonstrating the highest predictive values. These features can be assessed at multimodality breast imaging, particularly at breast MRI, which demonstrates high specificity and negative predictive value for determining nipple involvement in malignancy. Online supplemental material is available for this article. ^©RSNA, 2022.

Imaging Spectrum of Augmented Breast and Post-Mastectomy Reconstructed Breast with Common Complications: A Pictorial Essay

Breast augmentation is becoming more common, be it for cosmetic reasons or post-mastectomy. Multiple articles in the literature describe the imaging findings of various types of cosmetic breast augmentation. Some articles describe imaging findings for different types of post-mastectomy reconstructions. This essay aims to serve as a comprehensive reference for the multimodality imaging of various types of breast augmentations in native breast and post-mastectomy reconstructions. Familiarity with these findings will facilitate the detection of complications and new or recurrent breast malignancies in patients. With the extensive illustrations provided in this essay on normal and abnormal imaging findings of augmented breasts, readers will receive exposure that will facilitate effective practice.

Deep Inferior Epigastric Artery Perforator Flap Reconstruction for Breast Burn Deformities

The anterior chest wall is commonly involved in pediatric burn injuries. In women, deep thermal injuries may result in damage to the breast bud and breast skin, which can disrupt breast development and result in long-term deformities. In adulthood, the techniques frequently applied to correct these deformities focus on scar release in combination with skin grafting and implant-based procedures; however, these techniques often result in suboptimal aesthetic outcomes. In this report, we present superior outcomes from applying an autologous breast reconstruction technique to this challenging problem.

DIEAP Flap Breast Reconstruction Followed by Local Recurrence of Breast Cancer

Local recurrence after an autologous breast reconstruction is uncommon. We describe 2 patients with local recurrence 3 and 9 years, respectively, after mastectomy with DIEAP (deep inferior epigastric artery perforator) flap breast reconstruction. Patients generally present with a palpable mass, pain, or other visible abnormalities. Various imaging techniques are helpful, always completed by biopsy to characterize the tumour. A repeated sentinel node procedure can be useful in staging. The treatment of the local recurrence needs to be determined in a multidisciplinary team consultation.

Ultrasonography Findings of AlloDerm® Used in Postmastectomy Alloplastic Breast Reconstruction: A Case Report and Literature Review

AlloDerm^® (LifeCell Corp.; Brancburg, NJ) is an acellular dermal matrix (ADM) that serves as an immunologically inert scaffold in plastic surgery. In breast reconstruction, it is used as a filler for lumpectomy defects and can be used to create the inferolateral portion of the tissue expander pocket or implant pocket in postmastectomy patients. However, there are limited reports of the radiologic findings of AlloDerm^® in patients who have undergone postmastectomy reconstruction. Familiarity with the imaging features of AlloDerm^® is essential for correct diagnosis. We report the ultrasonography features of AlloDerm^® in a 43-year-old female patient 3 months after postmastectomy reconstruction. It may help distinguish AlloDerm^® from tumor recurrence or other foreign body materials such as gossypiboma. This is important as misdiagnosis can often lead to unnecessary surgical intervention.

Multimodality Imaging of the Reconstructed Breast

The purpose of this article is to illustrate the imaging characteristics and pathologic findings associated with various types of breast reconstruction in women who have undergone mastectomy to treat breast cancer. As the use of breast reconstruction becomes more prevalent, it is imperative that radiologists interpreting imaging studies identify normal and abnormal imaging findings associated with differing breast reconstruction techniques, recognize imaging manifestation of expected complications, and reliably distinguish these from malignancy.

Imaging Features of AlloDerm(®) Used in Postmastectomy Breast Reconstructions

The purpose of this pictorial essay is to demonstrate the imaging features (ultrasound, mammogram, and magnetic resonance imaging (MRI)) of AlloDerm^®(LifeCell Corp.; Branchburg, NJ), an acellular dermal matrix sometimes used in both primary and reconstructive breast surgeries. AlloDerm^® is derived from cadaveric dermis and provides an immunologically inert scaffold in tissue reconstruction. Since there is little literature on the imaging of this substance, radiologists may be unfamiliar with its appearance in breast imaging. For this manuscript, ex vivo and in vivo images of AlloDerm^® in postmastectomy patients were evaluated using different imaging modalities. The appearance of AlloDerm^® can vary based on length of time postsurgery and incorporation into the host. AlloDerm^® appears as an isodense to glandular tissue on a mammogram and isoechoic to glandular tissue on ultrasound imaging. On MRI, in comparison with normal breast parenchyma, AlloDerm^® is hyperintense on T2-weighted imaging and isointense on T1-weighted imaging and demonstrates mild enhancement. To the best of the authors’ knowledge, this is the first multimodality imaging description of AlloDerm^® used in postmastectomy patients. The conformation of AlloDerm^® at surgical placement and the degree of host cell migration and neoangiogenesis are factors to take into consideration when performing diagnostic evaluations; and, familiarity with the various imaging appearances of AlloDerm^® can be helpful to exclude residual or recurrent disease.