While contrast-enhanced mammography and contrast-enhanced MRI (CE-MRI) showed comparable diagnostic performance for detecting breast cancer, CE-MRI had superior sensitivity and negative likelihood ... Background Contrast-enhanced mammography (CEM) is a more accessible alternative to contrast-enhanced MRI (CE-MRI) in breast imaging, but a summary comparison of published studies is lacking. Purpos...

Objectives While magnetic resonance imaging (MRI) is considered a helpful diagnostic tool in breast imaging, discussions are ongoing about appropriate protocols and indications. The European Society of Breast Imaging (EUSOBI) launched a survey to evaluate the utilisation of breast MRI in clinical practice. Methods An online survey reviewed by the EUSOBI board and committees was distributed amongst members. The questions encompassed: training and experience; annual breast MRI and MRI-guided-intervention workload; examination protocols; indications; reporting habits and preferences. Data were summarised and subgroups compared using χ² test. Results Of 647 EUSOBI members, 177 (27.4%) answered the survey. The majority were radiologists (90.5%), half of them based in academic centres (51.9%). Common indications for MRI included cancer staging, treatment monitoring, high-risk screening and problem-solving, and differed significantly between countries (p≤0.03). Structured reporting and BI-RADS were mostly used. Breast radiologists with ≤10 years of experience preferred inclusion of additional techniques, such as T2/STIR (p=0.03) and DWI (p=0.08) in the scan protocol. MRI-guided interventions were performed by a minority of participants (35.4%). Conclusions The utilisation of breast MRI in clinical practice is generally in line with international recommendations. There are substantial differences between countries. MRI-guided interventions and functional MRI parameters are not widely available. Key points • MRI is commonly used for the detection and characterisation of breast lesions. • Clinical practice standards are generally in line with current recommendations. • Standardised criteria and diagnostic categories (mainly BI-RADS) are widely adopted. • Younger radiologists value additional techniques, such as T2/STIR and DWI. • MRI-guided breast biopsy is not widely available.

Numerous studies have analyzed associations between apparent diffusion coefficient (ADC) and histopathological features such as Ki-67 proliferation index in breast cancer (BC), with mixed results. The purpose of this study was to perform a multicenter analysis to determine relationships between ADC and expression of Ki-67 and tumor grade in BC. For this study, data from six centers were acquired. The sample comprises 870 patients (all female; mean age, 52.6 ± 10.8 years). In every case, breast magnetic resonance imaging with diffusion-weighted imaging was performed. The comparison of ADC values in groups was performed by Mann-Whitney U test where the p values are adjusted for multiple testing (Bonferroni correction). The association between ADC and Ki-67 values was calculated by Spearman’s rank correlation coefficient. Sensitivity, specificity, negative and positive predictive values, accuracy, and AUC were calculated for the diagnostic procedures. ADC thresholds were chosen to maximize the Youden index. Overall, data of 870 patients were acquired for this study. The mean ADC value of the tumors was 0.98 ± 0.22 × 10− 3 mm2 s− 1. ROC analysis showed that it is impossible to differentiate high/moderate grade tumors from grade 1 lesions using ADC values. Youden index identified a threshold ADC value of 1.03 with a sensitivity of 56.2% and specificity of 67.9%. The positive predictive value was 18.2%, and the negative predictive value was 92.4%. The level of the Ki-67 proliferation index was available for 845 patients. The mean value was 12.33 ± 21.77%. ADC correlated with weak statistical significant with expression of Ki-67 (p = − 0.202, p < 0.001). ROC analysis was performed to distinguish tumors with high proliferative potential from tumors with low expression of Ki-67 using ADC values. Youden index identified a threshold ADC value of 0.91 (sensitivity 64%, specificity 50%, positive predictive value 67.7%, negative predictive value 45.0%). ADC cannot be used as a surrogate marker for proliferation activity and/or for tumor grade in breast cancer.

Background: Contrast‐enhanced MRI (CE‐MRI) is the most sensitive technique for breast cancer detection. Contrast‐enhanced mammography (CEM) is emerging as a possible alternative to CE‐MRI.Purpose: To evaluate the diagnostic performance of a low radiation dose contrast‐enhanced mammography (L‐CEM) in women with suspicious findings on conventional imaging compared to CE‐MRI of the breast.Study Type: Prospective, single center.Population: Women with suspicious findings on mammography, tomosynthesis, or ultrasound, and no contraindications for L‐CEM or CE‐MRI. Eighty women were included.Field Strength/Sequence: 1.5 and 3T CE‐MRI, standard protocol for breast, with dedicated coils, according to international guidelines. L‐CEM was performed using a dedicated prototype.Assessment: Three, off‐site, blinded readers evaluated the images according to the BI‐RADS lexicon in a randomized order, each in two separate reading sessions. Histology served as a gold standard.Statistical Test: Lesion detection rate, sensitivity, specificity, and negative and positive predictive values (NPV, PPV) were calculated and compared with multivariate statistics.Results: Included were 80 women (mean age, 54.3 years ±11.2 standard deviation) with 93 lesions (32 benign, 61 malignant). The detection rate was significantly higher with CE‐MRI (92.5–94.6%; L‐CEM 79.6–91.4%, P = 0.014). Sensitivity (L‐CEM 65.6–90.2%; CE‐MRI 83.6–93.4%, P = 0.086) and NPV (L‐CEM 59.6–71.4%; CE‐MRI 63.0–76.5%, P = 0.780) did not differ between the modalities. Specificity (L‐CEM 46.9–96.9%; CE‐MRI 37.5–53.1%, P = 0.001) and PPV (L‐CEM 76.4–97.6%; CE‐MRI 73.3–77.3%, P = 0.007) were significantly higher with L‐CEM. Variations between readers were significant for sensitivity and NPV. The accuracy of L‐CEM was as good as CE‐MRI (75.3–76.3% vs. 72.0–75.3%, P = 0.514).Data Conclusion: L‐CEM showed a high sensitivity and accuracy in women with suspicious findings on conventional imaging. Compared to CE‐MRI, L‐CEM has the potential to increase specificity and PPV. L‐CEM might help to reduce false‐positive biopsies while obtaining sensitivity comparable to that of CE‐MRILevel of Evidence: 1Technical Efficacy Stage: 2 J. Magn. Reson. Imaging 2020;52:589–595.