Contrast enhanced spectral mammography (CESM) guided breast biopsy as an alternative to MRI guided biopsy

Objective: Contrast Enhanced Spectral Mammography (CESM) breast biopsy has been recently introduced into clinical practice. This short communication describes the technique and potential as an alternative to MRI guided biopsy. Methods and materials: An additional abnormality was detected on a breast MRI examination in a patient with lobular carcinoma. The lesion was occult on conventional mammography, tomosynthesis and ultrasound and required histological diagnosis. Traditionally this would have necessitated a MRI guided breast biopsy, but was performed under CESM guidance. Results: A diagnostic CESM study was performed to ensure the lesion visibility with CESM and then targeted under CESM guidance. A limited diagnostic study, CESM scout and paired images for stereotactic targeting were obtained within a 10 min window following a single injection of iodinated contrast agent. The time from positioning in the biopsy device to releasing compression after biopsy and marker clip placement was 15 min. The biopsy confirmed the presence of multifocal breast cancer. Conclusion: CESM guided breast biopsy is a new technique that can be successfully used as an alternative to MRI guided breast biopsy. Advances in knowledge: CESM guided biopsy can be used to sample breast lesions which remain occult on standard mammography and ultrasound.

Deep-Learning-Driven Full-Waveform Inversion for Ultrasound Breast Imaging

Ultrasound breast imaging is a promising alternative to conventional mammography because it does not expose women to harmful ionising radiation and it can successfully image dense breast tissue. However, conventional ultrasound imaging only provides morphological information with limited diagnostic value. Ultrasound computed tomography (USCT) uses energy in both transmission and reflection when imaging the breast to provide more diagnostically relevant quantitative tissue properties, but it is often based on time-of-flight tomography or similar ray approximations of the wave equation, resulting in reconstructed images with low resolution. Full-waveform inversion (FWI) is based on a more accurate approximation of wave-propagation phenomena and can consequently produce very high resolution images using frequencies below 1 megahertz. These low frequencies, however, are not available in most USCT acquisition systems, as they use transducers with central frequencies well above those required in FWI. To circumvent this problem, we designed, trained, and implemented a two-dimensional convolutional neural network to artificially generate missing low frequencies in USCT data. Our results show that FWI reconstructions using experiment data after the application of the proposed method successfully converged, showing good agreement with X-ray CT and reflection ultrasound-tomography images.

Radiological Assessment of Response to Neoadjuvant Chemotherapy in Breast Cancer Females, Using Standard and Spectral Mammography

Background Morphological assessment and measurement of the residual mass of the breast tumour following neoadjuvant chemotherapy (NACT) is the key to successful surgical treatment. The objective of our study was to evaluate the efficiency of contrast-enhanced spectral mammography (CESM) and conventional mammography (MMG) in detecting CR (complete response) following NACT, as well as to compare the efficiency of conventional mammography and contrast-enhanced spectral mammography is assessing the therapeutic response to NACT in breast cancer patients.Methods A retrospective analysis included 63 breast cancer subjects who had undergone neoadjuvant chemotherapy in the years 2016-2019. The inclusion criteria for the study included diagnosed breast cancer based on a core needle biopsy, a complete set of imaging examinations before the procedure consisted of digital mammography, contrast-enhanced spectral mammography and surgery performed before and after completed neoadjuvant chemotherapy. Results The average size of the tumours prior to neoadjuvant chemotherapy amounted to 34.37 mm for MMG and 34.34 mm for CESM, as well as 17.61 mm for MMG and 8.48 mm for CESM following NACT. The average size of the lesions in histopathological examination was 11.06 mm. Spearman’s analysis revealed a high level of correlation (R=0.89, p<0.01) upon comparing the maximum tumour dimensions prior to neoadjuvant chemotherapy on MMG and CESM, and a moderate level of correlation (R=0.57, p<0.01) upon comparing the maximum tumour dimensions post-NACT on MMG and CESM. While comparing the measurements of the maximum dimensions on MMG and CESM following NACT, with the maximum dimensions in histopathological examination, we can observe a low level of correlation for MMG (R=0.26, p<0.04) and a high level of correlation for CESM (R=0.67, p<0.01). The sensitivity of MMG in forecasting CR amounted to 33.33% and its specificity to 92.86%, whereas the same parameters for CESM were 85.71% and 71.42% respectively.Conclusions CESM demonstrates significantly higher sensitivity than MMG in forecasting CR in female patients receiving NACT due to breast cancer. CESM correlates well with the size of residual lesions in histopathological examination. However, it tends to underestimate the tumour size. In the assessment of post-NACT residual lesions, conventional mammography is an insufficient diagnostic tool.

Digital breast tomosynthesis (DBT) value in breast mass detection

Epidemiologically, breast cancer is the most common cancer in middle-aged women and it is one of the leading causes of cancer-related deaths. Middle-aged patients are covered by screening tests – digital mammography, often supplemented with ultrasound (US) breast examination. Other radiological tests in the diagnosis of breast cancer include such techniques as tomosynthesis, spectral mammography and magnetic resonance imaging (MRI). Many research groups around the world have demonstrated superiority of tomosynthesis in detecting focal lesions in breasts when compared to conventional mammography. Tomosynthesis usage was proposed for screening studies as a test of choice and for radiologically-guided tissue biopsies of suspicious tissue lesions.

Dual Energy X-ray Methods for the Characterization, Quantification and Imaging of Calcification Minerals and Masses in Breast

Dual energy (DE) technique has been used by numerous studies in order to detect breast cancer in early stages. Although mammography is the gold standard, the dual energy technique offers the advantage of the suppression of the contrast between adipose and glandular tissues and reveals pathogenesis that is not present in conventional mammography. Both dual energy subtraction and dual energy contrast enhanced techniques were used in order to study the potential of dual energy technique to assist in detection or/and visualization of calcification minerals, masses and lesions obscured by overlapping tissue. This article reviews recent developments in this field, regarding: i) simulation studies carried out for the optimizations of the dual energy technique used in order to characterize and quantify calcification minerals or/and visualize suspected findings, and ii) the subsequent experimental verifications, and finally, the adaptation of the dual energy technique in clinical practice.

The Value of Contrast Enhanced Spectral Mammography in BIRADS Categorization of Equivocal and Suspicious Breast Lesions

Aim To evaluate the capability of CESM to upgrade/downgrade BIRADS category of equivocal and suspicious breast lesions. Patients and Methods Thirty female patients with 44 equivocal and suspicious breast lesions, were enrolled in our study, age ranged from 20 to 76 years. All patients underwent conventional mammography and ultrasound then CESM. Results Mammography+Ultrasound categorized 40/44 lesions (90.9%) lesions to be malignant (BIRADS 4,5) and 4/44 lesions (9.1%) to be benign (BIRADS1,3). CESM categorized 35/44 lesions (79.5% )to be malignant (BIRADS 4,5) and 9/44 lesions (20.5% ) to be benign (BIRADS1,3). Disagreement about BIRADS category was observed in 25% of the examined lesions including upgraded and down graded lesions in 11.36 % and 13.6 % respectively. 100% of up/down graded lesions also proved CESM to be correct in reference to the final diagnosis. Conclusion CESM has better diagnostic performance than mammography plus Ultrasound and provides a valuable tool to accurately evaluate equivocal and suspicious breast lesions.

Assessment of the additional clinical potential of X-ray dark-field imaging for breast cancer in a preclinical setup

Background: Mammography can identify calcifications up to 50–100 μm in size as a surrogate parameter for breast cancer or ductal carcinoma in situ (DCIS). Microcalcifications measuring <50 µm are also associated with breast cancer or DCIS and are frequently not detected on mammography, although they can be detected with dark-field imaging. This study examined whether additional breast examination using X-ray dark-field imaging can increase the detection rate of calcifications. Advances in knowledge: (1) evaluation of additional modality of breast imaging; (2) specific evaluation of breast calcifications. Implications for patient care: the addition of X-ray dark-field imaging to conventional mammography could detect additional calcifications. Methods: Talbot–Lau X-ray phase–contrast imaging and X-ray dark-field imaging were used to acquire images of breast specimens. The radiation dosage with the technique is comparable with conventional mammography. Three X-ray gratings with periods of 5–10 µm between the X-ray tube and the flat-panel detector provide three different images in a single sequence: the conventional attenuation image, differential phase image, and dark-field image. The images were read by radiologists. Radiological findings were marked and examined pathologically. The results were described in a descriptive manner. Results: A total of 81 breast specimens were investigated with the two methods; 199 significant structures were processed pathologically, consisting of 123 benign and 76 malignant lesions (DCIS or invasive breast cancer). X-ray dark-field imaging identified 15 additional histologically confirmed carcinoma lesions that were visible but not declared suspicious on digital mammography alone. Another four malignant lesions that were not visible on mammography were exclusively detected with X-ray dark-field imaging. Conclusions: Adding X-ray dark-field imaging to digital mammography increases the detection rate for breast cancer and DCIS associated lesions with micrometer-sized calcifications. The use of X-ray dark-field imaging may be able to provide more accurate and detailed radiological classification of suspicious breast lesions. Adding X-ray dark-field imaging to mammography may be able to increase the detection rate and improve preoperative planning in deciding between mastectomy or breast-conserving therapy, particularly in patients with invasive lobular breast cancer.

Towards clinical grating-interferometry mammography

Objectives Grating-interferometry-based mammography (GIM) might facilitate breast cancer detection, as several research works have demonstrated in a pre-clinical setting, since it is able to provide attenuation, differential phase contrast, and scattering images simultaneously. In order to translate this technique to the clinics, it has to be adapted to cover a large field-of-view within a clinically acceptable exposure time and radiation dose. Methods We set up a grating interferometer that fits into a standard mammography system and fulfilled the aforementioned conditions. Here, we present the first mastectomy images acquired with this experimental device. Results and conclusion Our system performs at a mean glandular dose of 1.6 mGy for a 5-cm-thick, 18%-dense breast, and a field-of-view of 26 × 21 cm2. It seems to be well-suited as basis for a clinical-environment device. Further, dark-field signals seem to support an improved lesion visualization. Evidently, the effective impact of such indications must be evaluated and quantified within the context of a proper reader study. Key Points • Grating-interferometry-based mammography (GIM) might facilitate breast cancer detection, since it is sensitive to refraction and scattering and thus provides additional tissue information. • The most straightforward way to do grating-interferometry in the clinics is to modify a standard mammography device. • In a first approximation, the doses given with this technique seem to be similar to those of conventional mammography.