High-resolution spiral CT of the breast at very low dose: concept and feasibility considerations.

Objective: Mammography, today's standard imaging approach, has deficits with respect to the superimposition of anatomical structures. Dedicated CT of the breast so far indicated that it can provide superior soft-tissue imaging, but that it still has significant limitations with respect to spatial resolution and dose. We have assessed novel dedicated breast CT technology.

Spectral optimization for dedicated breast CT.

Purpose: The authors investigated the choice of spectra for the optimization of the dose-weighted contrast-to-noise ratio (CNRD) for a dedicated breast CT scanner. The objective is to provide the desired image quality level at minimal dose values. The CNRD was investigated as a function of energy or tube voltage and filtrations for various breast sizes and contrasts.

Application- and patient size-dependent optimization of x-ray spectra for CT.

Although x-ray computed tomography (CT) has been in clinical use for over 3 decades, spectral optimization has not been a topic of great concern; high voltages around 120 kV have been in use since the beginning of CT. It is the purpose of this study to analyze, in a rigorous manner, the energies at which the patient dose necessary to provide a given contrast-to-noise ratio (CNR) for various diagnostic tasks can be minimized. The authors used cylindrical water phantoms and quasianthropomorphic phantoms of the thorax and the abdomen with inserts of 13 mm diameter mimicking soft tissue, bone, and iodine for simulations and measurements.

Reduction of dose to the female breast in thoracic CT: a comparison of standard-protocol, bismuth-shielded, partial and tube-current-modulated CT examinations.

We evaluated the potential for reduction of dose to the female breast in computed tomography (CT) of the thorax by using three different techniques: bismuth shielding, partial CT scanning and tube-current modulation (TCM). Measurements and simulations of dose and image quality were performed for a 64-slice CT system using a semi-anthropomorphic thorax phantom with breasts added. Three-dimensional dose distributions were calculated by Monte Carlo (MC) methods.

Technical approaches to the optimisation of CT.

This paper reviews current technical approaches to the optimisation of CT practice, i.e. approaches to reduce patient dose to the necessary minimum.