The role of low keV virtual monochromatic imaging in increasing the conspicuity of primary breast cancer in dual-energy spectral thoracic CT examination for staging purposes

Background The additive value of dual-energy spectral computerized tomography (DESCT) in breast cancer imaging is still unknown. Purpose To investigate the role of DESCT in improving the conspicuity of primary breast cancer. Material and Methods Twenty-nine patients who were histopathologically diagnosed with breast cancer and underwent DESCT for staging of lung metastasis were evaluated retrospectively. The visual conspicuity of breast cancer was scored by two readers separately in reconstructed virtual monochromatic images obtained at 40, 60, 80, and 100 keV. A circular region of interest slightly smaller than the maximum contrasted portion of the primary breast cancer was manually placed. Iodine enhancement (HU) and iodine content (mg/mL) values of tumor, normal breast tissue and pectoral muscle, and contrast-to-noise values of images at four different energy levels were calculated. Results The lesion conspicuity score peaked at 40-keV series for both readers and was significantly higher than those at other energy levels (all P