Diagnostic Performance of Contrast-Enhanced Digital Mammography versus Conventional Imaging in Women with Dense Breasts

Contrast-enhanced mammography for breast cancer detection and diagnosis with high concentration iodinated contrast medium

OBJECTIVES

We assessed the diagnostic performance of contrast-enhanced mammography (CEM) using a high-concentration iodinated contrast medium (HCCM, 400 mgI/mL) to determine whether the reduced iodine dose and increased iodine delivery rate (IDR) achieved might offer a more sustainable alternative to CEM performed with lower iodine concentrations.

METHODS

This two-center retrospective study included 205 patients who underwent CEM between March 2021 and February 2022. Patients were injected with HCCM at 1.0 mL/kg bodyweight at an IDR of 1.2 gL/s. Standard cranio-caudal and mediolateral-oblique views were acquired. Images were reviewed independently by two experienced radiologists who were blinded to patient clinical and imaging information. Diagnostic performance, including sensitivity, specificity, and accuracy, was assessed based on histological or long-term imaging follow-up as the reference standard.

RESULTS

Among the 205 patients, 149 (72.7%) had malignant lesions, and 56 (27.3%) had benign findings. The sensitivity and specificity of CEM were 96-97% and 84-87.5%, respectively, with an overall accuracy of 93-95%. The IDR achieved with HCCM resulted in excellent contrast enhancement, particularly in patients with aggressive malignancies. ROC analysis confirmed the good diagnostic performance, with AUC values of 0.90-0.92. Compared to conventional mammography and ultrasound, CEM demonstrated significantly higher diagnostic accuracy, especially in patients with dense breast tissue.

CONCLUSIONS

CEM with HCCM provides excellent diagnostic performance, achieving high sensitivity and specificity while allowing for a reduced iodine dose and increased IDR. This approach may offer a more sustainable alternative to conventional contrast media without compromising diagnostic accuracy, particularly for the detection and characterization of aggressive breast lesions.

CRITICAL RELEVANCE STATEMENT

This study demonstrates that reducing the volume of injected contrast media while increasing iodine concentration maintains the diagnostic benefits of CEM, further supporting its potential to improve early cancer detection, thereby advancing clinical radiology practices and optimizing screening strategies for women with dense breasts.

KEY POINTS

Currently, CEM protocols utilize a variety of iodine concentrations and flow rates. CEM with high-concentration contrast (400 mgI/mL) achieved 96% sensitivity and 87.5% specificity. High-concentration contrast in CEM improves early detection of aggressive breast cancers.

Can Contrast-Enhanced Mammography Improve Positive Predictive Value for Diagnostic Workup of Suspicious Findings? A Single-Arm Prospective Study

OBJECTIVE

To assess the positive predictive value-3 (PPV3) and negative predictive value (NPV) of contrast-enhanced mammography (CEM) when added to the diagnostic workup of suspicious breast findings.

METHODS

This prospective study was IRB approved. We recruited 99 women with abnormal findings on digital breast tomosynthesis (DBT) and/or US to undergo CEM prior to biopsy. Based on final pathology outcomes, PPV3 and NPV were calculated and compared using N-1 chi-squared tests with P-values and 95% CIs.

RESULTS

Final pathologic outcome yielded 56.6% (56/99) benign, 5.1% (5/99) benign with upgrade potential (BWUP), and 38.4% (38/99) malignant lesions. Final pathologic outcomes for the 63 positive CEMs yielded 33.3% (21/63) benign, 6.3% (4/63) BWUP, and 60.3% (38/63) malignant lesions. Adding CEM to the diagnostic workup significantly increased PPV3 from 38.4% (38/99) to 60.3% (38/63) (P <.01; 95% CI, 6.1-36.2). Negative predictive value was 100% (36/36) for CEM, 92.9% (13/14; P = .1; 95% CI, -4.2 to 31.4) for DBT, and 75.9% (22/29; P <.05; 95% CI, 8.8-42.1) for US. The number of unnecessary biopsies could be reduced by 36.4% (from 100% [99/99] to 63.6% [63/99]).

CONCLUSION

Adding CEM to the diagnostic workup of suspicious breast findings could improve PPV3 to prevent unnecessary biopsies.

Digital Mammography, Tomosynthesis, and Contrast-Enhanced Mammography: Intraindividual Comparison of Mean Glandular Dose for Screening Examinations

BACKGROUND. Contrast-enhanced mammography (CEM) is growing in clinical use due to its increased sensitivity and specificity compared with full-field digital mammography (FFDM) and/or digital breast tomosynthesis (DBT), particularly in patients with dense breasts. OBJECTIVE. The purpose of this study was to perform an intraindividual comparison of mean glandular dose (MGD) with FFDM, DBT, a combination protocol using both FFDM and DBT (hereafter, combined FFDM-DBT), and CEM in patients undergoing breast cancer screening. METHODS. This retrospective study included 389 women (median age, 57.4 years) with an elevated risk of breast cancer who, as part of participation in an earlier prospective clinical trial, underwent breast cancer screening with combined FFDM-DBT and CEM between February 2019 and April 2021. A total of 764 breasts (383 left, 381 right) were evaluated. One craniocaudal (CC) view and one mediolateral oblique (MLO) view were evaluated per breast for each of FFDM, DBT, and CEM. MGD values were extracted from DICOM metadata. BI-RADS breast density categories were extracted from clinical radiology reports. Data were summarized descriptively, including determination of corresponding effective doses. RESULTS. The breast density category was A in zero patients, B in 44 patients (88 breasts), C in 306 patients (599 breasts), and D in 39 patients (77 breasts). The median MGD per breast (CC and MLO views combined) was 4.07 mGy for FFDM alone, 4.97 mGy for DBT alone, 9.38 mGy for combined FFDM-DBT, 3.96 mGy for low-energy CEM, 1.90 mGy for high-energy CEM, and 5.87 for CEM overall. Corresponding effective dose values were 0.49, 0.60, 1.13, 0.48, 0.23, and 0.70 mSv, respectively. The median MGD for density categories B, C, and D, respectively, was 4.01, 4.22, and 2.70 mGy for FFDM; 5.93, 4.93, and 3.17 mGy for DBT; and 5.90, 6.02, and 4.52 mGy for CEM. CONCLUSION. In this intraindividual comparative study of screening examinations, the MGD per breast was higher for CEM than for FFDM or DBT alone. However, these differences were small, and MGD was lower for CEM than for combined FFDM-DBT. CLINICAL IMPACT. These findings are relevant to ongoing considerations of the role of CEM in breast cancer screening pathways.

Diagnostic performance of the Kaiser score for contrast-enhanced mammography and magnetic resonance imaging in breast masses: A Comparative Study

RATIONALE AND OBJECTIVES

The Kaiser score (KS) is a simple and intuitive machine-learning derived decision rule for characterizing breast lesions in a clinical setting and screening for breast cancer. The present study aims to investigate the applicability of the KS for contrast-enhanced mammography (CEM) in breast masses, and to compare its diagnostic accuracy with magnetic resonance imaging (MRI). CEM may provide an alternative option for patients with breast masses, especially for those with MRI contraindications.

MATERIALS AND METHODS

Two hundred and seventy-five patients with breast enhanced masses were included in the study from May 2019 to September 2022. Patients were further divided into benign and malignant groups based on pathological diagnosis. The CEM and MRI imaging characteristics of these two groups were analyzed statistically. The paired chi-square and Cohen's kappa coefficient (κ) analysis were used to compare imaging characteristics between CEM and MRI. The Breast Imaging Reporting and Data System (BI-RADS) and KS for CEM and MRI were evaluated based on imaging characteristics. The diagnostic performance of BI-RADS and KS for CEM and MRI was assessed and compared using receiver operating characteristic (ROC) analysis and DeLong's test.

RESULTS

The imaging characteristics of root sign, time-signal intensity curve (TIC/mTIC), margin, internal enhancement pattern (IEP), edema, apparent diffusion coefficient (ADC) values, and suspicious malignant microcalcifications showed significant differences between benign and malignant lesions (all p ≤ 0.011). The detection rate of root sign and margin showed substantial agreement between CEM and MRI (κ = 0.656, κ = 0.640), but IEP, TIC/mTIC, and edema showed poor agreement (κ = 0.380, κ = 0.320, κ = 0.324). For all lesion analyses, the area under the curves (AUCs) of the KS (0.897 ∼ 0.932) were higher than that of BI-RADS (0.691) in CEM (all p < 0.001). The AUC of KS (calcification)-CEM (0.932) was higher than those of both KS-CEM and KS (edema)-CEM (0.897 and 0.899) (all p < 0.001). For subgroup analyses, the AUCs of the KS (0.875 ∼ 0.876) were higher than that of BI-RADS (0.740) in MRI (all p < 0.001). The AUCs of KS-MRI (0.876) and KS (ADC)-MRI (0.875) were similar to those of KS-CEM (0.878) and KS (edema)-CEM (0.870) (all p > 0.100). The AUC of KS (calcification)-CEM (0.934) was slightly higher than those of both KS-MRI (0.876) and KS (ADC)-MRI (0.875), but no significant difference was observed (p = 0.051; p = 0.071).

CONCLUSION

The KS for CEM provided high diagnostic accuracy in distinguishing breast masses, comparable to that of MRI. The application of KS (calcification)-CEM combined with suspicious malignant microcalcifications can improve diagnostic efficiency with an AUC of 0.932 ∼ 0.934. However, edema did not significantly improve performance when using the KS for CEM.

Does Contrast-Enhanced Mammography Outperform Digital Breast Tomosynthesis for Detection and Characterization of Breast Lesions or Vice Versa?

Mammograms are the mainstay of diagnostic breast imaging and cancer screening. Despite mammography advances like full-field digital mammography (FFDM) and digital breast tomosynthesis (DBT), these imaging techniques provide purely structural information. Though the most sensitive modality for breast cancer detection is magnetic resonance imaging (MRI), its widespread use has been limited due to high cost, long scan times, and lack of availability. Contrast-enhanced mammography (CEM) is a novel technique which combines dual energy FFDM with injection of iodinated contrast. It provides structural and functional imaging similar to MRI. The objectives of this study were to assess and compare the diagnostic performance of CEM and DBT in characterizing breast lesions and to analyze additional findings revealed by CEM and examining their implications for patient management. This was a single center prospective observational study on 58 women with BI-RADS category of 3, 4, and 5 breast lesions who underwent CEM following DBT. CEM detected 62 lesions, out of which 46 were categorized as suspicious/malignant and 16 as benign. On histopathology, 44 turned out to be malignant and 18 benign. CEM achieved a sensitivity of 100% and specificity of 88%. In contrast, DBT identified 56 of these 62 lesions (42 were malignant and 14 were benign on histopathology), with sensitivity of 95% and specificity of 77.8%. Compared to DBT, CEM provided superior delineation of disease extent, depicting multifocal and multicentric lesions, as well as picking up lesions in contralateral breasts, thereby altering patient management.

BPE on contrast-enhanced mammography: relationship with breast density, age and menopausal status

PURPOSE

This retrospective study aimed to evaluate the relationship between BPE on CEM and breast density, age and menopausal status.

MATERIAL AND METHODS

Our analysis included all women eligible for CEM as a second-level examination in the diagnostic phase in a 12-month period. CEM were performed on a dedicated low-dose digital mammography unit after the injection of 1.5 ml/kg body weight Iohexol 350 mgI/ml. Both breast composition and BPE were assessed independently by two breast radiologists according to the CEM supplement to the 2013 ACR BI-RADS Mammography. A two-stage ordered probit regression model was fitted to evaluate the relationship between BPE and the other factors considered.

RESULTS

49 patients were included (median age = 55 years, 28.6% premenopausal and 71.4% postmenopausal). Breast composition was classified as ACR BI-RADS a in 4.1%, ACR BI-RADS b in 36.7%, ACR BI-RADS c in 46.9%, and ACR BI-RADS d in 12.2% of cases, by both Readers. A BPE 1 category was assigned in 53.1-55.1% of patients (by Reader 1 and 2, respectively), BPE 2 in 22.4%, BPE 3 in 18.4-12.2%, and BPE 4 in 6.1-10.2%. Higher breast density was strongly associated with higher levels of BPE, while BPE was not directly associated with age, both in fertile and postmenopausal patients. No significant differences were observed between the two Readers.

CONCLUSION

Increased BPE is associated with a well-established breast cancer risk factor as high breast density, while it was not directly dependent on the other non-modifiable factors considered.

Contrast-Enhanced Mammography: A Literature Review of Clinical Uses for Cancer Diagnosis and Surgical Oncology

Contrast-enhanced mammography (CEM) uses intermittent dual-energy (low- and high-energy) exposures to produce low-energy mammograms and recombine enhanced images after the administration of iodized contrast medium, which provides more detailed information to detect breast cancers by using the features of morphology and abnormal uptake. In this article, we reviewed the literature to clarify the clinical applications of CEM, including (1) the fundamentals of CEM: the technique, radiation exposure, and image interpretation; (2) its clinical uses for cancer diagnosis, including problem-solving, palpable mass, suspicious microcalcification, architecture distortion, screening, and CEM-guided biopsy; and (3) the concerns of surgical oncology in pre-operative and neoadjuvant chemotherapy assessments. CEM undoubtedly plays an important role in clinical practice.

Mammographically detected breast clustered microcalcifications localized by chest thin-section computed tomography

BACKGROUND

To explore the capability and clinical significance of chest thin-section computed tomography (CT) for localization of mammographically detected clustered microcalcifications.

METHODS

A total of 69 patients with 71 mammographically detected clustered microcalcifications received surgical biopsy under the guidance of mammography (MG), CT was used to localize calcifications combined with MG if calcifications can be seen on CT. Intraoperative mammography of the specimens were performed in all cases for identification of the resected microcalcifications. The clinical, imaging and pathological information of these patients were analyzed.

RESULTS

A total of 42 (59.15%) cases of calcifications were localized by CT + MG, 29 (40.85%) cases were guided only by the mammography. All suspicious calcifications on the mammography were successfully removed. Pathological results showed 42 cases were cancer, 23 cases were benign, and 6 cases were atypical hyperplasia. The mean age in the CT + MG group was older than that of the MG group (54.12 vs. 49.27 years; P = 0.014). The maximum diameter of clusters of microcalcifications on mammography in the CT + MG group was larger than that of the MG group [(cranio-caudal view, 1.52 vs. 0.61 mm, P = 0.000; mediolateral oblique (MLO) view, 1.53 vs. 0.62 mm, P = 0.000)]. The gray value ratio (calcified area / paraglandular; MLO, P = 0.004) and the gray value difference (calcified area - paraglandular; MLO, P = 0.005) in the CT + MG group was higher than that of the MG group. Multivariate analysis showed that the max diameter of clusters of microcalcifications (MLO view) was a significant predictive factor of localization by CT in total patients (P = 0.001).

CONCLUSIONS

About half of the mammographically detected clustered microcalcifications could be localized by thin-section CT. Maximum diameter of clusters of microcalcifications (MLO view) was a predictor of visibility of calcifications by CT. Chest thin-section CT may be useful for localization of calcifications in some patients, especially for calcifications that are only visible in one view on the mammography.