Haydee Ojeda-Fournier

The California Breast Density Information Group: A Collaborative Response to the Issues of Breast Density, Breast Cancer Risk, and Breast Density Notification Legislation

In anticipation of breast density notification legislation in the state of California, which would require notification of women with heterogeneously and extremely dense breast tissue, a working group of breast imagers and breast cancer risk specialists was formed to provide a common response framework. The California Breast Density Information Group identified key elements and implications of the law, researching scientific evidence needed to develop a robust response. In particular, issues of risk associated with dense breast tissue, masking of cancers by dense tissue on mammograms, and the efficacy, benefits, and harms of supplementary screening tests were studied and consensus reached. National guidelines and peer-reviewed published literature were used to recommend that women with dense breast tissue at screening mammography follow supplemental screening guidelines based on breast cancer risk assessment. The goal of developing educational materials for referring clinicians and patients was reached with the construction of an easily accessible Web site that contains information about breast density, breast cancer risk assessment, and supplementary imaging. This multi-institutional, multidisciplinary approach may be useful for organizations to frame responses as similar legislation is passed across the United States. Online supplemental material is available for this article.

Recognizing and interpreting artifacts and pitfalls in MR imaging of the breast.

Magnetic resonance (MR) imaging of the breast has evolved into an important adjunctive tool in breast imaging with multiple and ever-increasing indications for its use. As with other types of MR imaging, there are a number of technical artifacts and pitfalls that can potentially limit interpretation of the images by masking or simulating disease. Because of the coils and computer-aided detection software specific to breast MR imaging, there are additional technical considerations that are unique to this type of MR imaging. Motion and misregistration artifacts, wraparound artifact, susceptibility artifact, poor fat saturation, lack of contrast material, and poor timing of the contrast material bolus are some of the artifacts and pitfalls that can make interpretation of breast MR images challenging and lead to misdiagnosis. Other important considerations in proper interpretation of breast MR images include acquisition of a sufficient medical history, knowledge of benign and abnormal lesion enhancement, morphologic versus kinetic assessment, evaluation of areas outside the breast, and positioning. By using the recommended strategies, one can reduce or eliminate common artifacts and pitfalls in breast MR imaging that prevent proper interpretation of the results of this important diagnostic tool.

Quantitative volumetric breast imaging with 3D inverse scatter computed tomography

A method was developed to map tissue properties of the entire breast including sound speed and attenuation using fully 3D nonlinear inverse-scattering tomography. Clinical measurements suggest that in breast tissue benign and cancerous lesions may be identified in part by these inherent acoustic parameters. Sound speed accuracy and linearity are very high over a wide range (1325-1700 m/sec) with ~1.5 mm resolution at 2 MHz in transmission mode. Attenuation tomograms provide image contrast over a wide range (0-4 dB/cm/MHz) and assist classification of masses. High resolution 0.6 mm volumetric reflection tomograms are acquired with bandwidth 2-8 MHz, are refraction-corrected with the transmission tissue data and are precisely registered in 3D with the transmission volumes. USCT promises an automated whole-breast scan providing a global view of the entire breast in 3D, facilitating comparison to prior exams in a reproducible geometry. Scanner design, automated operation and results of our trial with over 125 subjects with confirmed breast masses will be presented with detailed comparison to conventional sonography and MRI.

Evolving Paradigm for Imaging, Diagnosis, and Management of DCIS

Our understanding of the biology of breast cancer has dramatically expanded over the past decade, revealing that breast cancer is a heterogeneous group of diseases. This new knowledge can generate insights to improve screening performance and the management of ductal carcinoma in situ. In this article, the authors review the current state of the science of breast cancer and tools that can be used to improve screening and risk assessment. They describe several opportunities to improve clinical screening: (1) radiologists interpreting mammograms should aim to differentiate between the risk for invasive cancer and ductal carcinoma in situ to better assess the time frame for disease progression and the need for and optimal timing of biopsy; (2) imaging features associated with low risk, slow-growing cancer versus high risk, fast-growing cancer should be better defined and taught; and (3) as we learn more about assessing an individuals risk for developing breast cancer, we should incorporate these factors into a strategy for personalized screening to maximize benefit and minimize harm.

MRI for breast cancer: Current indications

Mammography is the only imaging study that has been proven in multiple large randomized trials to decrease breast cancer mortality. Mammography, however, has its limitations and, as such, other modalities that can complement it are being studied. One of these is dynamic contrast-enhanced breast MRI, which has emerged as an important adjunctive modality and is at present the most sensitive modality that we have to evaluate the breast. The American College of Radiology, in its 2004 practice guidelines, has outlined the 12 current indications for breast MRI. This manuscript reviews and provides examples of each of these.

Ultrasound Evaluation of Regional Breast Lymph Nodes

Through the early 1990s, ultrasound (US) had traditionally been used to characterize breast masses as either cystic or solid. With technological advancements, US indications for breast evaluation have significantly broadened. High-frequency transducers, color flow Doppler capabilities, and improved morphology descriptors culminate in enhanced characterization of various mesenchymal tissues, including fat, blood vessels, breast parenchyma, nerves, calcifications and connective tissue; this allows for identification of the previously elusive lymph node (LN). US’s clinical applicability has dramatically evolved, and US evaluation of loco-regional LNs is now routinely used as part of the standard protocol in the multidisciplinary approach to evaluating, staging, and following of breast cancer patients. Breast cancer is the most common cancer in American women, with an estimated 192,370 new cases of invasive breast cancer and an additional 62,280 cases of in situ breast cancer in 2009. 1 Documenting LN metastasis has been established as an important predictor of recurrence and survival, and allows for accurate stratification of patients into different treatmentoptions.LNscanbepresentwithinanyquadrantof the breast. Lymphatic drainage of the breast occurs via the axillary, internal mammary, and infra and supraclavicular basins. In the evaluation of patients with breast cancer, US has been shown to accurately differentiate LNs, even when nonpalpable, from surrounding tissue and visualize changes to their size, shape, borders, and cortex. 2 Physical examination is widely recognized as inaccurate, with reported sensitivity rates close to 32% in the detection of axillary metastasis compared with 73% for US. 3 US also has the distinct advantage of real-time guidance capabilities that allow for relatively inexpensive and technically easy cytologic evaluation by fine-needle aspiration (FNA) and histologic tissue sampling by core biopsy (CB). In some instances, US evaluation of axillary LNs will help patientsavoidthetime,cost,andanxietyofsentinelLNbiopsy. 4

Quantitative analysis of vascular heterogeneity in breast lesions using contrast-enhanced 3-D harmonic and subharmonic ultrasound imaging

Ability to visualize breast lesion vascularity and quantify the vascular heterogeneity using contrast-enhanced 3-D harmonic (HI) and subharmonic (SHI) ultrasound imaging was investigated in a clinical population. Patients (n = 134) identified with breast lesions on mammography were scanned using power Doppler imaging, contrast-enhanced 3-D HI, and 3-D SHI on a modified Logiq 9 scanner (GE Healthcare). A region of interest corresponding to ultrasound contrast agent flow was identified in 4D View (GE Medical Systems) and mapped to raw slice data to generate a map of time-intensity curves for the lesion volume. Time points corresponding to baseline, peak intensity, and washout of ultrasound contrast agent were identified and used to generate and compare vascular heterogeneity plots for malignant and benign lesions. Vascularity was observed with power Doppler imaging in 84 lesions (63 benign and 21 malignant). The 3-D HI showed flow in 8 lesions (5 benign and 3 malignant), whereas 3-D SHI visualized flow in 68 lesions (49 benign and 19 malignant). Analysis of vascular heterogeneity in the 3-D SHI volumes found benign lesions having a significant difference in vascularity between central and peripheral sections (1.71 ± 0.96 vs. 1.13 ± 0.79 dB, p <; 0.001, respectively), whereas malignant lesions showed no difference (1.66 ± 1.39 vs. 1.24 ± 1.14 dB, p = 0.24), indicative of more vascular coverage. These preliminary results suggest quantitative evaluation of vascular heterogeneity in breast lesions using contrast-enhanced 3-D SHI is feasible and able to detect variations in vascularity between central and peripheral sections for benign and malignant lesions.

Accelerated Partial Breast Irradiation and Posttreatment Imaging Evaluation

Accelerated partial breast irradiation (APBI) is a technique that allows irradiation of only that part of the breast that is at greatest risk for recurrence of breast cancer. Because only a portion of the breast is irradiated, APBI can be performed in a relatively short period of time, usually in 5 days rather than the traditional 6 weeks. When used in carefully selected patients, APBI also allows normal portions of the breast parenchyma and regional vital organs to be spared from unnecessary irradiation. Common post-APBI imaging findings include focal skin thickening, seroma, scar, and skin retraction. Studies are underway that will compare a cohort of patients who underwent whole-breast irradiation with a cohort who underwent APBI to help determine whether the two techniques lead to significantly different imaging findings. Additional multicenter studies will be needed to document and analyze any such differences. In the future, APBI may play a significant role in selected patients, with pretherapy dynamic contrast material-enhanced magnetic resonance imaging of the breast possibly aiding in the selection process.

Inter-reader Variability in the Use of BI-RADS Descriptors for Suspicious Findings on Diagnostic Mammography: A Multi-institution Study of 10 Academic Radiologists

RATIONALE AND OBJECTIVES The study aimed to determine the inter-observer agreement among academic breast radiologists when using the Breast Imaging Reporting and Data System (BI-RADS) lesion descriptors for suspicious findings on diagnostic mammography. MATERIALS AND METHODS Ten experienced academic breast radiologists across five medical centers independently reviewed 250 de-identified diagnostic mammographic cases that were previously assessed as BI-RADS 4 or 5 with subsequent pathologic diagnosis by percutaneous or surgical biopsy. Each radiologist assessed the presence of the following suspicious mammographic findings: mass, asymmetry (one view), focal asymmetry (two views), architectural distortion, and calcifications. For any identified calcifications, the radiologist also described the morphology and distribution. Inter-observer agreement was determined with Fleiss kappa statistic. Agreement was also calculated by years of experience. RESULTS Of the 250 lesions, 156 (62%) were benign and 94 (38%) were malignant. Agreement among the 10 readers was strongest for recognizing the presence of calcifications (k = 0.82). There was substantial agreement among the readers for the identification of a mass (k = 0.67), whereas agreement was fair for the presence of a focal asymmetry (k = 0.21) or architectural distortion (k = 0.28). Agreement for asymmetries (one view) was slight (k = 0.09). Among the categories of calcification morphology and distribution, reader agreement was moderate (k = 0.51 and k = 0.60, respectively). Readers with more experience (10 or more years in clinical practice) did not demonstrate higher levels of agreement compared to those with less experience. CONCLUSIONS Strength of agreement varies widely for different types of mammographic findings, even among dedicated academic breast radiologists. More subtle findings such as asymmetries and architectural distortion demonstrated the weakest agreement. Studies that seek to evaluate the predictive value of certain mammographic features for malignancy should take into consideration the inherent interpretive variability for these findings.

Breast magnetic resonance imaging for monitoring response to therapy.

There is no difference in disease-free or overall survival in patients who undergo adjuvant versus neoadjuvant chemotherapy. Thus, neoadjuvant chemotherapy is recommended in patients with locally advanced breast cancer who would like to consider breast conservation, and is also the primary treatment in patients with inflammatory breast cancer. Magnetic resonance has emerged as the most sensitive imaging modality to assess the response of tumor to neoadjuvant chemotherapy.