Abstract: A fast neutron scintillator screen includes a converter material and a scintillator material in contact with the converter material. The converter material comprises a hydrogenous material, exhibits a thickness of from about 10 ?m to about 1500 ?m, and is formulated to produce recoil protons responsive to interactions with neutrons. The scintillator material comprises a phosphor formulated to produce photons responsive to interactions with the recoil protons. A method of conducting neutron radiography is also disclosed, as well as a system comprising the fast neutron scintillator screen.

Abstract: The patient's ECG signal is employed in a traverse-and-rotate type CT scanner as a time base for triggering the beginning of a traverse such that the traveling beam reaches the heart at a desired phase of the cardiac cycle. For a purely-rotational-type CT scanner, continuously generated scan data is only stored for corresponding phases of successive cardiac cycles. Alternatively, gating of the beams themselves can be controlled by the ECG signal. The use of a pacemaker to stabilize the cardiac period is described along with a system for recognizing unacceptable variations in the cardiac period. In a traverse-and-rotate-type fan-beam CT scanner, the effective beam width is narrowed to hasten the traverse of the heart.