Combined Optical and X-ray Tomosynthesis Breast Imaging

Abstract

Purpose:To explore the optical and physiologic properties of normal and lesion-bearing breasts by using a combined optical and digital breast tomosynthesis (DBT) imaging system. Materials and Methods:Institutional review board approval and patient informed consent were obtained for this HIPAA-compliant study. Combined optical and tomosynthesis imaging analysis was performed in 189 breasts from 125 subjects (mean age, 56 years 6 13 [standard deviation]), including 138 breasts with negative fi ndings and 51 breasts with lesions. Threedimensional (3D) maps of total hemoglobin concentration (Hb T ), oxygen saturation (S O 2 ), and tissue reduced scattering coeffi cients were interpreted by using the coregistered DBT images. Paired and unpaired t tests were performed between various tissue types to identify signifi cant differences. Results:The estimated average bulk Hb T from 138 normal breasts was 19.2 m mol/L. The corresponding mean SO 2 was 0.73, within the range of values in the literature. A linear correlation ( R = 0.57, P , .0001) was found between Hb T and the fi broglandular volume fraction derived from the 3D DBT scans. Optical reconstructions of normal breasts revealed structures corresponding to chest-wall muscle, fi broglandular, and adipose tissues in the Hb T , SO 2 , and scattering images. In 26 malignant tumors of 0.6-2.5 cm in size, Hb T was signifi cantly greater than that in the fibroglandular tissue of the same breast ( P = .0062). Solid benign lesions ( n = 17) and cysts ( n = 8) had signifi cantly lower Hb T contrast than did the malignant lesions ( P = .025 and P = .0033, respectively). Conclusion:The optical and DBT images were structurally consistent. The malignant tumors and benign lesions demonstrated different Hb T and scattering contrasts, which can potentially be exploited to reduce the false-positive rate of conventional mammography and unnecessary biopsies. BREAST IMAGING: Combined Optical and X-ray Tomosynthesis Breast Imaging Fang et al cancers and the reduction of the number of biopsies of benign lesions, compared with stand-alone conventional mammography.Our purpose was to explore the optical and physiologic properties of normal and lesion-bearing breasts by using a combined optical and DBT imaging system. Materials and MethodsThe experimental protocols were approved by the institutional review board (Massachusetts General Hospital), and written informed consent was obtained from all subjects. The study was compliant with Health Insurance Portability and Accountability Act guidelines. Imaging InstrumentationA photograph of the combined optical and DBT imaging system and probes is shown in Figures E1 and E2 (online). The detailed confi guration of the imaging physiologic parameters, such as the concentrations of oxygenated hemoglobin (Hb O ), deoxygenated hemoglobin (Hb R ), water, and lipids ( 16 ). With DOT, nearinfrared lasers, either radiofrequencymodulated, continuous-wave or pulsed, are used to probe tissue structure noninvasively ( 13,17 ). The concentrations of the tissue ...

Diffuse optical mammotomography: state-of-the-art and prospects

“…As to the functional parameters, from Table 2 it is seen that the ranges of characteristic values of haemoglobin oxygen saturation essentially overlap in healthy breast tissue and malignant tissue, namely, 49 -92% and 38 -81%. However, the ratio of haemoglobin concentrations of a cancer tumour and healthy tissue lies within 1.4 -1.9 [129,145,146,150,154,179,225,226], and the ratio of tissue optical indices within 2.2 -7.5 [145,179,225]. These facts confirm the possibility of getting good contrast in visualising the corresponding parameters and, therefore, successful recognition of malignant neoplasms against the background of the healthy breast tissues.…”

Integration of microwave tomography with magnetic resonance for improved breast imaging

“…Concurrent combination breast imaging in the diagnostic/screening setting has been dominated by the addition of optical methods to conventional modalities, for example, to x-rays, [45][46][47] ultrasound, 48,49 and MR; 42,50 most likely because optical technologies offer the potential of molecular specificity that can be integrated with clinically accepted breast imaging methods at moderate cost. We have experience at Dartmouth with multimodality combinations involving diffuse light in the near-infrared, termed Near InfraRed Spectral Tomography (NIRST), and have developed platforms with breast x-ray tomosynthesis 51,52 and MR. 53,54 Similar to MT, NIRST alone provides molecular specificity in terms of intrinsic breast tissue composition, but at poor spatial resolution, and when used in combination is significantly advantaged by the high-resolution spatial information provided by traditional breast imaging.…”

A digital x-ray tomosynthesis coupled near infrared spectral tomography system for dual-modality breast imaging

“…Since light transport in this regime is dominated by scattering, NIRST images are diffuse and lack high-resolution spatial detail, but when viewed in conjunction with a high resolution structural imaging modality, can provide complementary physiologic information to potentially improve overall diagnostic accuracy. This general approach of combining a structural imaging modality with a functional imaging technique has gained significant traction in recent years with several dual modality approaches being developed and tested clinically including optical imaging combined with MRI, Ultrasound, Mammography and DBT [5][6][7][8][9]. The most clinically successful implementation of dual modality imaging has been the combination of Positron Emission Tomography and Computed Tomography (PET-CT), where lower resolution PET imaging provides functional contrast to supplement higher resolution structural CT.…”