Imaging-therapy computed tomography with quasi-monochromatic X-rays.

Introduction: Computed tomography (CT) is a widespread and highly precise technique working in the energy range around 50-100 keV. For radiotherapy, however, the MeV energy range enables a better dose distribution. This gap between diagnosis and therapy can be overcome by the use of a modified CT machine in combination with heavy elements targeted to the tumour and used as photoelectric radiation enhancer.

Contrast-to-noise ratios of different elements in digital mammography: evaluation of their potential as new contrast agents.

Purpose: To determine the contrast-to-noise ratios (CNRs) of different elements at different energies using various anode/filter combinations currently employed in digital mammography. The elements investigated included not only elements already used in conventional contrast agents such as gadolinium and iodine but also other elements to investigate their potential as mammographic contrast agents.

Materials And Methods: The CNRs of 20 mmol/L bismuth (Bi), gadolinium (Gd), ytterbium (Yb), dysprosium (Dy), and iodine (I) were determined at different slice thicknesses (0.