Frequent Amplification and Overexpression of PSMA in Basallike Breast Cancer from Analysis of The Cancer Genome Atlas.

Prostate-specific membrane antigen (PSMA) is frequently overexpressed in nonprostate malignancies. This preclinical study investigated the molecular basis of the application of PMSA-targeting radiopharmaceuticals in breast cancer subtypes. Methods: The somatic copy number status and the transcriptomic and protein expressions of FOLH1 (gene name of PSMA) were analyzed across breast cancer subtypes in 998 patients from The Cancer Genome Atlas dataset. Results: FOLH1 was frequently amplified in basallike breast cancer (BLBC) (32%) compared with luminal and human epidermal growth factor receptor 2-positive subtypes (16% and 17%, respectively; P < 0.01). FOLH1 expression was higher in BLBC (P < 0.001) and was negatively correlated with estrogen-receptor and progesterone-receptor expressions. Consistently, the PSMA protein level was higher in BLBC (P < 0.05). Interestingly, FOLH1 expression was associated with relapse-free and distant metastasis-free survival in patients with BLBC. Conclusion: The BLBC subtype exhibited frequent amplification and overexpression of PSMA, supporting the exploration of PSMA-targeting radiopharmaceuticals in this aggressive breast cancer subtype.

The Postoperative Breast: Imaging Findings and Diagnostic Pitfalls After Breast-Conserving Surgery and Oncoplastic Breast Surgery.

Breast surgery is the cornerstone of treatment for early breast cancer. Historically, mastectomy and conventional breast-conserving surgery (BCS) were the main surgical techniques for treatment. Now, oncoplastic breast surgery (OBS), introduced in the 1990s, allows for a combination of BCS and reconstructive surgery to excise the cancer while preserving or enhancing the contour of the breast, leading to improved aesthetic results. Although imaging after conventional lumpectomy demonstrates typical postsurgical changes with known evolution patterns over time, OBS procedures show postsurgical changes/fat necrosis in locations other than the lumpectomy site. The purpose of this article is to familiarize radiologists with various types of surgical techniques for removal of breast cancer and to distinguish benign postoperative imaging findings from suspicious findings that warrant further work-up.

Multishot Diffusion-Weighted MRI of the Breasts in the Supine vs. Prone Position.

BACKGROUND: Diffusion-weighted imaging (DWI) may allow for breast cancer screening MRI without a contrast injection. Multishot methods improve prone DWI of the breasts but face different challenges in the supine position. PURPOSE: To establish a multishot DWI (msDWI) protocol for supine breast MRI and to evaluate the performance of supine vs. prone msDWI. STUDY TYPE: Prospective. POPULATION: Protocol optimization: 10 healthy women (ages 22-56), supine vs. prone: 24 healthy women (ages 22-62) and five women (ages 29-61) with breast tumors. FIELD STRENGTH/SEQUENCE: 3-T, protocol optimization msDWI: free-breathing (FB) 2-shots, FB 4-shots, respiratory-triggered (RT) 2-shots, RT 4-shots, supine vs. prone: RT 4-shot msDWI, T2-weighted fast-spin echo. ASSESSMENT: Protocol optimization and supine vs. prone: three observers performed an image quality assessment of sharpness, aliasing, distortion (vs. T2), perceived SNR, and overall image quality (scale of 1-5). Apparent diffusion coefficients (ADCs) in fibroglandular tissue (FGT) and breast tumors were measured. STATISTICAL TESTS: Effect of study variables on dichotomized ratings (4/5 vs. 1/2/3) and FGT ADCs were assessed with mixed-effects logistic regression. Interobserver agreement utilized Gwet's agreement coefficient (AC). Lesion ADCs were assessed by Bland-Altman analysis and concordance correlation (ρc ). P value <0.05 was considered statistically significant. RESULTS: Protocol optimization: 4-shots significantly improved sharpness and distortion; RT significantly improved sharpness, aliasing, perceived SNR, and overall image quality. FGT ADCs were not significantly different between shots (P = 0.812), FB vs. RT (P = 0.591), or side (P = 0.574). Supine vs. prone: supine images were rated significantly higher for sharpness, aliasing, and overall image quality. FGT ADCs were significantly higher supine; lesion ADCs were highly correlated (ρc  = 0.92). DATA CONCLUSION: Based on image quality, supine msDWI outperformed prone msDWI. Lesion ADCs were highly correlated between the two positions, while FGT ADCs were higher in the supine position. EVIDENCE LEVEL: 2. TECHNICAL EFFICACY: Stage 1.

Compositional Processing Emerges in Neural Networks Solving Math Problems.

A longstanding question in cognitive science concerns the learning mechanisms underlying compositionality in human cognition. Humans can infer the structured relationships (e.g., grammatical rules) implicit in their sensory observations (e.g., auditory speech), and use this knowledge to guide the composition of simpler meanings into complex wholes. Recent progress in artificial neural networks has shown that when large models are trained on enough linguistic data, grammatical structure emerges in their representations. We extend this work to the domain of mathematical reasoning, where it is possible to formulate precise hypotheses about how meanings (e.g., the quantities corresponding to numerals) should be composed according to structured rules (e.g., order of operations). Our work shows that neural networks are not only able to infer something about the structured relationships implicit in their training data, but can also deploy this knowledge to guide the composition of individual meanings into composite wholes.

Impact of the COVID-19 Pandemic on Breast Imaging Education.

OBJECTIVE: To determine the impact of the COVID-19 pandemic on breast imaging education. METHODS: A 22-item survey addressing four themes during the early pandemic (time on service, structured education, clinical training, future plans) was emailed to Society of Breast Imaging members and members-in-training in July 2020. Responses were compared using McNemar's and Mann-Whitney U tests; a general linear model was used for multivariate analysis. RESULTS: Of 136 responses (136/2824, 4.8%), 96 U.S. responses from radiologists with trainees, residents, and fellows were included. Clinical exposure declined during the early pandemic, with almost no medical students on service (66/67, 99%) and fewer clinical days for residents (78/89, 88%) and fellows (48/68, 71%). Conferences shifted to remote live format (57/78, 73%), with some canceled (15/78, 19%). Compared to pre-pandemic, resident diagnostic (75/78, 96% vs 26/78, 33%) (P < 0.001) and procedural (73/78, 94% vs 21/78, 27%) (P < 0.001) participation fell, as did fellow diagnostic (60/61, 98% vs 47/61, 77%) (P = 0.001) and procedural (60/61, 98% vs 43/61, 70%) (P < 0.001) participation. Most thought that the pandemic negatively influenced resident and fellow screening (64/77, 83% and 43/60, 72%, respectively), diagnostic (66/77, 86% and 37/60, 62%), and procedural (71/77, 92% and 37/61, 61%) education. However, a majority thought that decreased time on service (36/67, 54%) and patient contact (46/79, 58%) would not change residents' pursuit of a breast imaging fellowship. CONCLUSION: The pandemic has had a largely negative impact on breast imaging education, with reduction in exposure to all aspects of breast imaging. However, this may not affect career decisions.

A behavioral training protocol using visual perceptual learning to improve a visual skill.

We describe a behavioral training protocol using visual perceptual learning (VPL) to improve visual detection skills in non-experts for subtle mammographic lesions indicative of breast cancer. This protocol can be adapted for the professional training of experts (radiologists) or to improve visual skills for other tasks, such as the detection of targets in photo or video surveillance. For complete details on the use and execution of this protocol, please refer to Frank et al. (2020a).

Diffusion-weighted double-echo steady-state with a three-dimensional cones trajectory for non-contrast-enhanced breast MRI.

The image quality limitations of echo-planar diffusion-weighted imaging (DWI) are an obstacle to its widespread adoption in the breast. Steady-state DWI is an alternative DWI method with more robust image quality but its contrast for imaging breast cancer is not well-understood. The aim of this study was to develop and evaluate diffusion-weighted double-echo steady-state imaging with a three-dimensional cones trajectory (DW-DESS-Cones) as an alternative to conventional DWI for non-contrast-enhanced MRI in the breast. This prospective study included 28 women undergoing clinically indicated breast MRI and six asymptomatic volunteers. In vivo studies were performed at 3 T and included DW-DESS-Cones, DW-DESS-Cartesian, DWI, and CE-MRI acquisitions. Phantom experiments (diffusion phantom, High Precision Devices) and simulations were performed to establish framework for contrast of DW-DESS-Cones in comparison to DWI in the breast. Motion artifacts of DW-DESS-Cones were measured with artifact-to-noise ratio in volunteers and patients. Lesion-to-fibroglandular tissue signal ratios were measured, lesions were categorized as hyperintense or hypointense, and an image quality observer study was performed in DW-DESS-Cones and DWI in patients. Effect of DW-DESS-Cones method on motion artifacts was tested by mixed-effects generalized linear model. Effect of DW-DESS-Cones on signal in phantom was tested by quadratic regression. Correlation was calculated between DW-DESS-Cones and DWI lesion-to-fibroglandular tissue signal ratios. Inter-observer agreement was assessed with Gwet's AC. Simulations predicted hyperintensity of lesions with DW-DESS-Cones but at a 3% to 67% lower degree than with DWI. Motion artifacts were reduced with DW-DESS-Cones versus DW-DESS-Cartesian (p < 0.05). Lesion-to-fibroglandular tissue signal ratios were not correlated between DW-DESS-Cones and DWI (r = 0.25, p = 0.38). Concordant hyperintensity/hypointensity was observed between DW-DESS-Cones and DWI in 11/14 lesions. DW-DESS-Cones improved sharpness, distortion, and overall image quality versus DWI. DW-DESS-Cones may be able to eliminate motion artifacts in the breast allowing for investigation of higher degrees of steady-state diffusion weighting. Malignant breast lesions in DW-DESS-Cones demonstrated hyperintensity with respect to surrounding tissue without an injection of contrast. LEVEL OF EVIDENCE: 2. TECHNICAL EFFICACY STAGE: 1.

Adaptations of Breast Imaging Centers to the COVID-19 Pandemic: A Survey of California and Texas.

OBJECTIVE: To determine the early impact of the COVID-19 pandemic on breast imaging centers in California and Texas and compare regional differences. METHODS: An 11-item survey was emailed to American College of Radiology accredited breast imaging facilities in California and Texas in August 2020. A question subset addressed March-April government restrictions on elective services ("during the shutdown" and "after reopening"). Comparisons were made between states with chi-square and Fisher's tests, and timeframes with McNemar's and paired t-tests. RESULTS: There were 54 respondents (54/240, 23%, 26 California, 28 Texas). Imaging volumes fell during the shutdown and remained below pre-pandemic levels after reopening, with reduction in screening greatest (ultrasound 12% of baseline, mammography 13%, MRI 23%), followed by diagnostic MRI (43%), procedures (44%), and diagnostics (45%). California reported higher volumes during the shutdown (procedures, MRI) and after reopening (diagnostics, procedures, MRI) versus Texas (P = 0.001-0.02). Most screened patients (52/54, 96% symptoms and 42/54, 78% temperatures), and 100% (53/53) modified check-in and check-out. Reading rooms or physician work were altered for social distancing (31/54, 57%). Physician mask (45/48, 94%), gown (15/48, 31%), eyewear (22/48, 46%), and face shield (22/48, 46%) use during procedures increased after reopening versus pre-pandemic (P < 0.001-0.03). Physician (47/54, 87%) and staff (45/53, 85%) financial impacts were common, but none reported terminations. CONCLUSION: Breast imaging volumes during the early pandemic fell more severely in Texas than in California. Safety measures and financial impacts on physicians and staff were similar in both states.

Supervised Learning Occurs in Visual Perceptual Learning of Complex Natural Images.

There have been long-standing debates regarding whether supervised or unsupervised learning mechanisms are involved in visual perceptual learning (VPL) [1-14]. However, these debates have been based on the effects of simple feedback only about response accuracy in detection or discrimination tasks of low-level visual features such as orientation [15-22]. Here, we examined whether the content of response feedback plays a critical role for the acquisition and long-term retention of VPL of complex natural images. We trained three groups of human subjects (n = 72 in total) to better detect "grouped microcalcifications" or "architectural distortion" lesions (referred to as calcification and distortion in the following) in mammograms either with no trial-by-trial feedback, partial trial-by-trial feedback (response correctness only), or detailed trial-by-trial feedback (response correctness and target location). Distortion lesions consist of more complex visual structures than calcification lesions [23-26]. We found that partial feedback is necessary for VPL of calcifications, whereas detailed feedback is required for VPL of distortions. Furthermore, detailed feedback during training is necessary for VPL of distortion and calcification lesions to be retained for 6 months. These results show that although supervised learning is heavily involved in VPL of complex natural images, the extent of supervision for VPL varies across different types of complex natural images. Such differential requirements for VPL to improve the detectability of lesions in mammograms are potentially informative for the professional training of radiologists.

SUPERA interwoven nitinol Stent Outcomes in Above-Knee IntErventions (SAKE) study.

PURPOSE: To report experience with the novel interwoven-wire self-expanding nitinol SUPERA stent (IDEV Technologies, Inc/Abbott Laboratories, Inc, Webster, Texas) for the treatment of severely diseased superficial femoral and popliteal arteries. MATERIALS AND METHODS: Consecutive patients with severely diseased superficial femoral and popliteal arteries who received SUPERA stents (n = 80 patients [98 limbs]; mean age, 70.8 y; 80% male) were retrospectively identified. Patients were followed for an average of 14.3 months after intervention. RESULTS: Total occlusions were present in 39% of the lesions, 21% had tissue loss, and 61% demonstrated calcification on fluoroscopy. Patients were prescribed dual antiplatelet therapy (aspirin and clopidogrel) for at least 30 days unless contraindicated, followed by aspirin alone indefinitely. The mean (± SD) lesion length was 143 mm (± 98). Based on need for clinical intervention, primary patency was 96.9% at 6 months and 85.8% at 12 months (Kaplan-Meier estimates). Assisted primary patency and secondary patency rates at 12 months were 96.8% and 100%, respectively. Ankle-brachial index increased from 0.60 at baseline to 0.83 at last follow-up (P < .001). No stent fractures were found by fluoroscopy inspection in 19 limbs (16 patients) that required reintervention. CONCLUSIONS: Based on experience with multiple operators at a single clinical center, the interwoven nitinol stent design provides a viable option for high-grade obstructive disease in the femoropopliteal artery.

Transradial alcohol septal ablation.

Radial access is shown to have fewer access-related complications when compared to femoral artery access. While two small European studies have examined the feasibility of transradial access for alcohol septal ablations, no reports from the United States have yet been published. We report the case of a 69-year-old male with hypertrophic cardiomyopathy who underwent alcohol septal ablation via the right radial artery approach and discuss the technique.

ACR Appropriateness Criteria® on nonpalpable mammographic findings (excluding calcifications).

Screening mammography can detect breast cancer before it becomes clinically apparent. However, the screening process identifies many false-positive findings for each cancer eventually confirmed. Additional tools are available to help differentiate spurious findings from real ones and to help determine when tissue sampling is required, when short-term follow-up will suffice, or whether the finding can be dismissed as benign. These tools include additional diagnostic mammographic views, breast ultrasound, breast MRI, and, when histologic evaluation is required, percutaneous biopsy. The imaging evaluation of a finding detected at screening mammography proceeds most efficiently, cost-effectively, and with minimization of radiation dose when approached in an evidence-based manner. The appropriateness of the above-referenced tools is presented here as they apply to a variety of findings often encountered on screening mammography; an algorithmic approach to workup of these potential scenarios is also included. The recommendations put forth represent a compilation of evidence-based data and expert opinion of the ACR Appropriateness Criteria(®) Expert Panel on Breast Imaging.

DCE-MRI parameters have potential to predict response of locally advanced breast cancer patients to neoadjuvant chemotherapy and hyperthermia: a pilot study.

UNLABELLED: Combined therapies represent a staple of modern medicine. For women treated with neoadjuvant chemotherapy (NA ChT) for locally advanced breast cancer (LABC), early determination of whether the patient will fail to respond can enable the use of alternative, more beneficial therapies. This is even more desirable when the combined therapy includes hyperthermia (HT), an efficient way to improve drug delivery, however, more costly and time consuming. There is data showing that this goal can be achieved using magnetic resonance imaging (MRI) with contrast agent (CA) enhancement. This work for the first time proposes combining the information extracted from pre-treatment MR imaging into a morpho-physiological tumour score (MPTS) with the hypothesis that this score will increase the prognostic efficacy, compared to each of its MR-derived components: morphological (derived from the shape of the tumour enhancement) and physiological (derived from the CA enhancement variance dynamics parameters). The MPTS was correlated with response as determined by both pathologic residual tumour and MRI imaging, and was shown to have potential to predict response. The MPTS was extracted from pre-treatment MRI parameters, so independent of the combined therapy used. PURPOSE: To use a novel morpho-physiological tumour score (MPTS) generated from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to predict response to treatment. MATERIALS AND METHODS: A protocol was designed to acquire DCE-MRI images of 20 locally advanced breast cancer (LABC) patients treated with neoadjuvant chemotherapy (NA ChT) and hyperthermia (HT). Imaging was done over 30 min following bolus injection of gadopentetate-based contrast agent. Parametric maps were generated by fitting the signal intensity to a double exponential curve and were used to derive a morphological characterisation of the lesions. Enhancement-variance dynamics parameters, wash-in and wash-out parameters (WiP, WoP), were extracted. The morphological characterisation and the WiP and WoP were combined into a MPTS with the intent of achieving better prognostic efficacy. The MPTS was correlated with response to NA therapy as determined by pathological residual tumour and MRI imaging. RESULTS: The contrast agent in all tumours typically peaked in the first 1-4 min. The tumours' WiP and WoP varied considerably. The MPTS was highly correlated with whether the patients had a pathological response. This scoring system has a specificity of 78% and a sensitivity of 91% for predicting response to NA chemotherapy. The kappa was 0.69 with a 95% confidence interval of [0.38, 1] and a p-value of 0.002. CONCLUSIONS: This pilot study shows that the MPTS derived using pre-treatment MRI images has the potential to predict response to NA ChT and HT in LABC patients. Further prospective studies are needed to confirm the validity of these results.

The role of radiotracer imaging in the diagnosis and management of patients with breast cancer: part 2--response to therapy, other indications, and future directions.

Breast cancer is the most common non-skin type of cancer and the second leading cause of cancer mortality in women. Advances in diagnosis and treatment have led to declines in mortality, despite an increase in breast cancer incidence. An advancing array of both local and systemic therapy options has led to increasingly individualized treatment. Imaging plays a key role in detecting breast cancer and directing its therapy. This continuing education article provides a comprehensive review of current and future radiotracer imaging methods applied to breast cancer, in the context of breast cancer management strategies and other nonnuclear imaging methods. Part 1 of the review provided an overview of clinical and biologic considerations in breast cancer and covered radionuclide imaging for detection and staging. Part 2 covers radionuclide imaging of breast cancer response to therapy, other clinical indications for radionuclide breast cancer imaging, and future directions, including molecular imaging.

The role of radiotracer imaging in the diagnosis and management of patients with breast cancer: part 1--overview, detection, and staging.

Breast cancer is the most common non-skin type of cancer and the second leading cause of cancer mortality in women. Advances in diagnosis and treatment have led to declines in mortality, despite an increase in breast cancer incidence. An advancing array of both local and systemic therapy options has led to increasingly individualized treatment. Imaging plays a key role in detecting breast cancer and directing its therapy. This continuing education article, part 1 in a 2-part series, provides a comprehensive review of current and future radiotracer imaging methods applied to breast cancer, in the context of breast cancer management strategies and other nonnuclear imaging methods. Part 1 of the review provides an overview of clinical and biologic considerations in breast cancer and covers radionuclide imaging for detection and staging. Part 2 will cover radionuclide imaging of breast cancer response to therapy, other clinical indications for radionuclide breast cancer imaging, and future directions, including molecular imaging.

BI-RADS MRI enhancement characteristics of ductal carcinoma in situ.

To identify the Breast Imaging Reporting and Data System magnetic resonance imaging (MRI) enhancement characteristics of ductal carcinoma in situ (DCIS). A retrospective review of consecutive patients who underwent breast MRI for newly diagnosed breast carcinoma prior to surgery was conducted. This yielded 381 lesions in 361 patients with pathologic confirmation of either DCIS alone, invasive carcinoma alone, or mixed invasive and in-situ disease. Presence or absence of a MRI lesion at the site of the documented carcinoma was recorded, and for all identified MRI lesions the Breast Imaging Reporting and Data System morphology patterns were recorded. MRI features of the different malignancy types were compared utilizing Fisher's exact tests; 64/381 (16.8%) lesions had DCIS, 101/381 (26.5%) had invasive carcinoma, and 216/381 (56.7%) had mixed invasive/in situ carcinoma. A MRI lesion corresponding to the known cancer was identified in 55/64 (85.9%) cases of DCIS, 98/101 (97.0%) cases of invasive carcinoma, and 212/216 (98.1%) cases of mixed invasive and in-situ carcinoma. For pure DCIS lesions, 38/64 (59.4%) exhibited nonmass-like enhancement (NMLE), 9/64 (14.1%) were masses, and 8/64 (12.5%) were a focus. For pure invasive carcinomas 79/101(78.2%) were masses, 16/101 (15.8%) were NMLE, and 3/101 (3.0%) were a focus. For mixed lesions 163/216 (75.5%) were masses, 44/216 (20.4%) demonstrated NMLE, and 5/216 (2.3%) were a focus. The most common NMLE patterns of pure DCIS were segmental distribution and clumped internal enhancement. Although there is overlap in the MRI morphology and enhancement pattern of in situ and invasive breast carcinoma, DCIS more frequently manifests as NMLE than does invasive carcinoma.

Cancer yield of probably benign breast MR examinations.

PURPOSE: To evaluate the cancer yield, frequency of use, and follow-up compliance of breast MR examinations assessed as "probably benign." MATERIALS AND METHODS: We retrospectively reviewed our MR database of 809 consecutive examinations between January 2003 and June 2004. We identified all examinations that ultimately received an MR breast imaging reporting and data system (BI-RADS) 3 assessment and recommendation for a short-interval follow-up MR with or without an antecedent targeted ultrasound. The clinical indication for breast MR, date of the follow-up examination, follow-up assessment, and any pathology findings through June 2005 were collected from clinical records and radiology and pathology reports. Frequency of BI-RADS 3 use, follow-up compliance, and cancer yield were calculated. RESULTS: A total of 160 out of 809 (20%) examinations comprise the study population. A total of 100 out of 160 (63%) women returned for the recommended follow-up MR, in which three out of 100 (3%) were upgraded to BI-RADS 4 with biopsy recommended. One patient underwent biopsy and the result was benign. A total of seven out of 160 (4%) underwent mastectomy in lieu of MR for known cancer elsewhere in the breast. One out of seven mastectomy specimens contained malignancy that corresponded to the probably benign finding, resulting in a cancer yield of one out of 160 (0.6%). CONCLUSION: Our data suggest that follow-up MR is a valid alternative to biopsy for MR BI-RADS 3 lesions.

FDG PET, PET/CT, and breast cancer imaging.

Currently, the clinical role of positron emission tomography (PET) and PET/computed tomography (CT) in patients with breast cancer is to provide additional information in select scenarios in which results of conventional imaging are indeterminate or of limited utility. There is currently no clinical role for fluorodeoxyglucose (FDG) PET in detection of breast cancer or evaluation of axillary lymph nodes, but these are areas of active research. FDG PET is complementary to conventional staging procedures and should not be a replacement for either bone scintigraphy or diagnostic CT. FDG PET and PET/CT have been shown to be particularly useful in the restaging of breast cancer, in evaluation of response to therapy, and as a problem-solving method when results of conventional imaging are equivocal. In these situations, FDG PET often demonstrates locoregional or unsuspected distant disease that affects management. PET has demonstrated a particular capability for evaluation of chemotherapy response in both patients with locally advanced breast carcinoma and those with metastatic disease.

MRI-guided vacuum-assisted breast biopsy with a handheld portable biopsy system.

OBJECTIVE: The purpose of this study was to evaluate a compact portable 10-gauge handheld battery-operated vacuum-assisted biopsy system for MRI-guided breast biopsy. CONCLUSION: The compact portable battery-operated biopsy system can be used successfully for MRI-guided core breast biopsy and is an alternative to current systems.