Faculty Bibliography

Patients with locally advanced invasive breast cancers are often treated with neoadjuvant chemotherapy prior to definitive surgical intervention. The primary aims of this approach are to: 1) reduce tumor burden thereby permitting breast conservation rather than mastectomy; 2) promptly treat possible metastatic disease, whether or not it is detectable on preoperative staging; and 3) potentially tailor future chemotherapeutic decisions by monitoring in-vivo tumor response. Accurate radiological assessment permits optimal management and planning in this population. However, assessment of tumor size and response to treatment can vary depending on the modality used, the measurement technique (such as single longest diameter, 3-D measurements, or calculated tumor volume), and varied response of different tumor subtypes to neoadjuvant chemotherapy (such as concentric shrinkage or tumor fragmentation). As discussed in further detail, digital mammography, digital breast tomosynthesis, US and MRI represent the key modalities with potential to help guide patient management. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Breast cancer screening recommendations are based on risk factors. For average-risk women, screening mammography and/or digital breast tomosynthesis is recommended beginning at age 40. Ultrasound (US) may be useful as an adjunct to mammography for incremental cancer detection in women with dense breasts, but the balance between increased cancer detection and the increased risk of a false-positive examination should be considered in the decision. For intermediate-risk women, US or MRI may be indicated as an adjunct to mammography depending upon specific risk factors. For women at high risk due to prior mantle radiation between the ages of 10 to 30, mammography is recommended starting 8 years after radiation therapy but not before age 25. For women with a genetic predisposition, annual screening mammography is recommended beginning 10 years earlier than the affected relative at the time of diagnosis but not before age 30. Annual screening MRI is recommended in high-risk women as an adjunct to mammography. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

OBJECTIVES: The aim of this study was to assess the applicability of Dixon radial volumetric encoding (Dixon-RAVE) for comprehensive dynamic contrast-enhanced 3D magnetic resonance imaging (MRI) of the breast using a combination of radial sampling, model-based fat/water separation, compressed sensing, and parallel imaging. MATERIALS AND METHODS: In this Health Insurance Portability and Accountability Act-compliant prospective study, 24 consecutive patients underwent bilateral breast MRI, including both conventional fat-suppressed and non-fat-suppressed precontrast T1-weighted volumetric interpolated breath-hold examination (VIBE). Afterward, 1 continuous Dixon-RAVE scan was performed with the proposed approach while the contrast agent was injected. This scan was immediately followed by the acquisition of 4 conventional fat-saturated VIBE scans. From the comprehensive Dixon-RAVE data set, different image contrasts were reconstructed that are comparable to the separate conventional VIBE scans.Two radiologists independently rated image quality, conspicuity of fibroglandular tissue from fat (FG), and degree of fat suppression (FS) on a 5-point Likert-type scale for the following 3 comparisons: precontrast fat-suppressed (pre-FS), precontrast non-fat-suppressed (pre-NFS), and dynamic fat-suppressed (dyn-FS) images. RESULTS: When scores were averaged over readers, Dixon-RAVE achieved significantly higher (P < 0.001) degree of fat suppression compared with VIBE, for both pre-FS (4.25 vs 3.67) and dyn-FS (4.10 vs 3.46) images. Although Dixon-RAVE had lower image quality score compared with VIBE for the pre-FS (3.56 vs 3.67, P = 0.490), the pre-NFS (3.54 vs 3.88, P = 0.009), and the dyn-FS images (3.06 vs 3.67, P < 0.001), acceptable or better diagnostic quality was achieved (score >/= 3). The FG score for Dixon-RAVE in comparison to VIBE was significantly higher for the pre-FS image (4.23 vs 3.85, P = 0.044), lower for the pre-NFS image (3.98 vs 4.25, P = 0.054), and higher for the dynamic fat-suppressed image (3.90 vs 3.85, P = 0.845). CONCLUSIONS: Dixon-RAVE can serve as a one-stop-shop approach for comprehensive T1-weighted breast MRI with diagnostic image quality, high spatiotemporal resolution, reduced overall scan time, and improved fat suppression compared with conventional imaging.

OBJECTIVE: Ultrafast dynamic contrast-enhanced magnetic resonance imaging of the breast enables assessment of the contrast inflow dynamics while providing images with diagnostic spatial resolution. However, the slice thickness of common ultrafast techniques still prevents multiplanar reconstruction. In addition, some temporal blurring of the enhancement characteristics occurs in case view-sharing is used. We evaluate a prototype compressed-sensing volume-interpolated breath-hold examination (CS-VIBE) sequence for ultrafast breast MRI that improves through plane spatial resolution and avoids temporal blurring while maintaining an ultrafast temporal resolution (less than 5 seconds per volume). Image quality (IQ) of the new sequence is compared with an ultrafast view-sharing sequence (time-resolved angiography with interleaved stochastic trajectories [TWIST]), and assessment of lesion morphology is compared with a regular T1-weighted 3D Dixon sequence (VIBE-DIXON) with an acquisition time of 91 seconds. MATERIALS AND METHODS: From April 2016 to October 2016, 30 women were scanned with the CS-VIBE sequence, replacing the routine ultrafast TWIST sequence in a hybrid breast MRI protocol. The need for informed consent was waived. All MRI scans were performed on a 3T MAGNETOM Skyra system (Siemens Healthcare, Erlangen, Germany) using a 16-channel bilateral breast coil. Two reader studies were conducted involving 5 readers. In the first study, overall IQ of CS-VIBE and TWIST in the axial plane was independently rated for 23 women for whom prior MRI examinations with TWIST were available. In addition, the presence of several types of artifacts was rated on a 5-point scale. The second study was conducted in women (n = 16) with lesions. In total, characteristics of 31 lesions (5 malignant and 26 benign) were described independently for CS-VIBE and VIBE-DIXON, according to the BI-RADS MRI-lexicon. In addition, a lesion conspicuity score was given. RESULTS: Using CS-VIBE, a much higher through-plane spatial resolution was achieved in the same acquisition time as with TWIST, without affecting in-plane IQ (P = 0.260). Time-resolved angiography with interleaved stochastic trajectories showed slightly more motion artifacts and infolding and ghosting artifacts compared with CS-VIBE, whereas CS-VIBE showed more breathing and pulsation artifacts. For morphologic assessment, intrareader agreement between CS-VIBE and the more time-consuming VIBE-DIXON was slight to almost perfect, and generally higher than interreader agreement. Mean sensitivity (84.0% and 92.0% for CS-VIBE and VIBE-DIXON, P = 0.500) and specificity (60.0% and 55.4% for CS-VIBE and VIBE-DIXON, P = 0.327) were comparable for both sequences. CONCLUSIONS: Compressed-sensing volume-interpolated breath-hold examination allows an increase of the through-plane spatial resolution of ultrafast dynamic contrast-enhanced magnetic resonance imaging compared with TWIST at a comparable in-plane IQ. Morphological assessment of lesions using CS-VIBE is comparable to VIBE-DIXON, which takes 18 times longer. Consequently, CS-VIBE enables 3D evaluation of breast lesions in ultrafast breast MRI.

PURPOSE: Diffusion-weighted imaging (DWI) and 18 F-fluorodeoxyglucose-positron emission tomography (18 F-FDG-PET) independently correlate with malignancy in breast cancer, but the relationship between their structural and metabolic metrics is not completely understood. This study spatially correlates diffusion, perfusion, and glucose avidity in breast cancer with simultaneous PET/MR imaging and compares correlations with clinical prognostics. METHODS: In this Health Insurance Portability and Accountability Act-compliant prospective study, with written informed consent and approval of the institutional review board and using simultaneously acquired FDG-PET and DWI, tissue diffusion (Dt ), and perfusion fraction (fp ) from intravoxel incoherent motion (IVIM) analysis were registered to FDG-PET within 14 locally advanced breast cancers. Lesions were analyzed using 2D histograms and correlation coefficients between Dt , fp , and standardized uptake value (SUV). Correlations were compared with prognostics from biopsy, metastatic burden from whole-body PET, and treatment history. RESULTS: SUV||Dt correlation coefficient significantly distinguished treated (0.11 +/- 0.24) from nontreated (-0.33 +/- 0.26) patients (P = 0.005). SUV||fp correlations were on average negative for the whole cohort (-0.17 +/- 0.13). CONCLUSION: Simultaneously acquired and registered FDG-PET/DWI allowed quantifiable descriptions of breast cancer microenvironments that may provide a framework for monitoring and predicting response to treatment. Magn Reson Med, 2016. (c) 2016 International Society for Magnetic Resonance in Medicine.

Breast cancer is the most common non-skin cancer and the second leading cause of cancer death for women in the United States. Before the introduction of widespread mammographic screening in the mid-1980s, the death rate from breast cancer in the US had remained unchanged for more than 4 decades. Since 1990, the death rate has declined by at least 38%. Much of this change is attributed to early detection with mammography. ACR breast cancer screening experts have reviewed data from RCTs, observational studies, US screening data, and other peer-reviewed literature to update our recommendations. Mammography screening has consistently been shown to significantly reduce breast cancer mortality over a variety of study designs. The ACR recommends annual mammography screening starting at age 40 for women of average risk of developing breast cancer. Our recommendation is based on maximizing proven benefits, which include a substantial reduction in breast cancer mortality afforded by regular screening and improved treatment options for those diagnosed with breast cancer. The risks associated with mammography screening are also considered to assist women in making an informed choice.

RATIONALE AND OBJECTIVES: To evaluate uptake, patterns of use, and perception of digital breast tomosynthesis (DBT) among practicing breast radiologists. MATERIALS AND METHODS: Institutional Review Board exemption was obtained for this Health Insurance Portability and Accountability Act-compliant electronic survey, sent to 7023 breast radiologists identified via the Radiological Society of North America database. Respondents were asked of their geographic location and practice type. DBT users reported length of use, selection criteria, interpretive sequences, recall rate, and reading time. Radiologist satisfaction with DBT as a diagnostic tool was assessed (1-5 scale). RESULTS: There were 1156 (16.5%) responders, 65.8% from the United States and 34.2% from abroad. Of these, 749 (68.6%) use DBT; 22.6% in academia, 56.5% private, and 21% other. Participants are equally likely to report use of DBT if they worked in academics versus in private practice (78.2% [169 of 216] vs 71% [423 of 596]) (odds ratio, 1.10; 95% confidence interval: 0.87-1.40; P = 1.000). Of nonusers, 43% (147 of 343) plan to adopt DBT. No US regional differences in uptake were observed (P = 1.000). Although 59.3% (416 of 702) of DBT users include synthetic 2D (s2D) for interpretation, only 24.2% (170 of 702) use s2D alone. Majority (66%; 441 of 672) do not perform DBT-guided procedures. Radiologist (76.6%) (544 of 710) satisfaction with DBT as a diagnostic tool is high (score >/= 4/5). CONCLUSIONS: DBT is being adopted worldwide across all practice types, yet variations in examination indication, patient selection, utilization of s2D images, and access to DBT-guided procedures persist, highlighting the need for consensus and standardization.

PURPOSE: To compare a novel multicoil compressed sensing technique with flexible temporal resolution, golden-angle radial sparse parallel (GRASP), to conventional fat-suppressed spoiled three-dimensional (3D) gradient-echo (volumetric interpolated breath-hold examination, VIBE) MRI in evaluating the conspicuity of benign and malignant breast lesions. MATERIALS AND METHODS: Between March and August 2015, 121 women (24-84 years; mean, 49.7 years) with 180 biopsy-proven benign and malignant lesions were imaged consecutively at 3.0 Tesla in a dynamic contrast-enhanced (DCE) MRI exam using sagittal T1-weighted fat-suppressed 3D VIBE in this Health Insurance Portability and Accountability Act-compliant, retrospective study. Subjects underwent MRI-guided breast biopsy (mean, 13 days [1-95 days]) using GRASP DCE-MRI, a fat-suppressed radial "stack-of-stars" 3D FLASH sequence with golden-angle ordering. Three readers independently evaluated breast lesions on both sequences. Statistical analysis included mixed models with generalized estimating equations, kappa-weighted coefficients and Fisher's exact test. RESULTS: All lesions demonstrated good conspicuity on VIBE and GRASP sequences (4.28 +/- 0.81 versus 3.65 +/- 1.22), with no significant difference in lesion detection (P = 0.248). VIBE had slightly higher lesion conspicuity than GRASP for all lesions, with VIBE 12.6% (0.63/5.0) more conspicuous (P < 0.001). Masses and nonmass enhancement (NME) were more conspicuous on VIBE (P < 0.001), with a larger difference for NME (14.2% versus 9.4% more conspicuous). Malignant lesions were more conspicuous than benign lesions (P < 0.001) on both sequences. CONCLUSION: GRASP DCE-MRI, a multicoil compressed sensing technique with high spatial resolution and flexible temporal resolution, has near-comparable performance to conventional VIBE imaging for breast lesion evaluation. LEVEL OF EVIDENCE: 3 J. Magn. Reson. Imaging 2016.

PURPOSE: To assess the diagnostic utility of contrast kinetic analysis for breast lesions and background parenchyma of women undergoing MRI-guided biopsies, for whom standard clinical analysis had failed to separate benign and malignant lesions. MATERIALS AND METHODS: This study included 115 women who had indeterminate lesions based on routine diagnostic breast MRI exams and underwent an MRI (3 Tesla) -guided biopsy of one or more lesions suspicious for breast cancer. Breast dynamic contrast-enhanced (DCE)-MRI was performed using a radial stack-of-stars three-dimensional spoiled gradient echo pulse sequence and modified k-space weighted image contrast image reconstruction. Contrast kinetic model analysis was conducted to characterize the contrast enhancement patterns measured in lesions and background parenchyma (BP). The transfer rate (Ktrans ), interstitial volume fraction (ve ), and vascular volume fraction (vp ) estimated from the lesion and BP were used to separate malignant from benign lesions. RESULTS: The patients with malignant lesions had significantly (P < 0.05) higher median lesion-Ktrans (0.081 min-1 ), higher median BP-Ktrans (0.032 min-1 ), and BP-vp (0.020) than those without malignant lesions (0.056 min-1 , 0.017 min-1 and 0.012, respectively). The area under the receiver operating characteristic curve (AUC) of the BP-Ktrans (0.687) was highest among the single parameters and higher than that of the lesion-Ktrans (0.664). The combined logistic regression model of lesion-Ktrans , lesion-ve , BP-Ktrans , BP-ve , and BP-vp had the highest AUC of 0.730. CONCLUSION: Our results suggest that the contrast kinetic analysis of DCE-MRI data can be used to differentiate the malignant lesions from the benign and high-risk lesions among the indeterminate breast lesions recommended for MRI-guided biopsy exams. LEVEL OF EVIDENCE: 3 J. Magn. Reson. Imaging 2016.

Breast cancer is the most common female malignancy and the second leading cause of female cancer death in the United States. Although the majority of palpable breast lumps are benign, a new palpable breast mass is a common presenting sign of breast cancer. Any woman presenting with a palpable lesion should have a thorough clinical breast examination, but because many breast masses may not exhibit distinctive physical findings, imaging evaluation is necessary in almost all cases to characterize the palpable lesion. Recommended imaging options in the context of a palpable mass include diagnostic mammography and targeted-breast ultrasound and are dependent on patient age and degree of radiologic suspicion as detailed in the document Variants. There is little role for advanced technologies such as MRI, positron emission mammography, or molecular breast imaging in the evaluation of a palpable mass. When a suspicious finding is identified, biopsy is indicated. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.