The Potential Role of Dedicated 3D Breast CT as a Diagnostic Tool: Review and Early Clinical Examples

Abstract

Mammography is the gold standard in routine screening for the detection of breast cancer in the general population. However limitations in sensitivity, particularly in dense breasts, has motivated the development of alternative imaging techniques such as digital breast tomosynthesis, whole breast ultrasound, breast specific gamma imaging, and more recently dedicated breast computed tomography or “breast CT”. Virtually all diagnostic work-ups of asymptomatic nonpalpable findings arise from screening mammography. In most cases, diagnostic mammography and ultrasound are sufficient for diagnosis, with magnetic resonance imaging (MRI) playing an occasional role. Digital breast tomosynthesis, a limited-angle tomographic technique, is increasingly being used for screening. Dedicated breast CT has full three-dimensional (3D) capability with near-isotropic resolution, which could potentially improve diagnostic accuracy. In current dedicated breast CT clinical prototypes, 300-500 low-dose projections are acquired in a circular trajectory around the breast using a flat panel detector, followed by image reconstruction to provide the 3D breast volume. The average glandular dose to the breast from breast CT can range from as little as a two-view screening mammogram to approximately that of a diagnostic mammography examination. Breast CT displays 3D images of the internal structures of the breast; therefore, evaluation of suspicious features like microcalcifications, masses, and asymmetries can be made in multiple anatomical planes from a single scan. The potential role of breast CT for diagnostic imaging is illustrated here through clinical examples such as imaging soft tissue abnormalities and microcalcifications. The potential for breast CT to serve as an imaging tool for extent of disease evaluation and for monitoring neoadjuvant chemotherapy response is also illustrated.

Digital breast tomosynthesis guided near infrared spectroscopy: volumetric estimates of fibroglandular fraction and breast density from tomosynthesis reconstructions

“…Since we validated the VBD T with FFDM, and dedicated breast CT provides higher resolution than breast MRI (Vedantham et al, 2014, O'Connell et al, 2014), VBD determined using breast CT was chosen for comparison. Also, both DBT and breast CT attempt to reconstruct the linear attenuation coefficients thus providing a direct comparison of a physical measure based breast density estimate.…”

A comparison of digital mammography detectors and emerging technology

“…Although these have the advantage of using no ionising radiation, DBCT has higher spatial resolution, quicker examination times and images have a similar appearance to mammograms. 86,87 Advanced software applications Even without upgrading to new imaging technologies, advanced software applications may provide additional useful information from existing mammography images.…”

“…A cone-beam of X-rays and a flat panel detector make a single rotation around the breast in less than 10 s 83e85 DBCT images are not compromised by tissue superimposition. 84e87 It therefore shows improved sensitivity in dense breasts 86 and volumetric breast density quantification is possible. 84 The radiation dose is similar to that from a two-view screening mammography examination, typically 2e4 mGy.…”

Intramammary Findings on CT of the Chest – a Review of Normal Anatomy and Possible Findings

“…The preoperative use of CT in addition to mammography and ultrasound increased breast conservation rates because of the better delineation of tumor extent [5]. Interestingly, dedicated breast CT and contrast-enhanced mammography have been recently introduced into clinical practice and showed promising results [6,7]. The use of contrast media facilitates the detection of malignant findings, because breast tumors show an increased contrast media uptake in comparison with the normal breast tissue (Figure 1).…”