Patent ID: 8706199

Claim:
A liquid injector for injecting at least a contrast medium into a subject whose fluoroscopic image is to be captured by an imaging diagnostic apparatus, wherein said contrast medium is available in a plurality of types having different concentrations of an effective component, said liquid injector, comprising: a liquid injection mechanism for injecting at least said contrast medium into said subject; a display/touch panel displaying icons for use in selecting a body portion; and control means for accepting a selection of the icons for selecting the body portion and for controlling operation of said liquid injection mechanism under operating conditions whose data have been read; said control means is configured: (i) to read out a base-operation condition including data of: a predetermined injection time for injection corresponding to the selected body portion, a necessary dose of an effective component of the contrast medium per unit weight of the subject corresponding to the selected body portion, a concentration of the effective component, and an injection rate, (ii) to calculate a necessary volume of the contrast medium based on the read out necessary dose of effective component per unit weight, weight of the subject, and concentration of the effective component, (iii) to make an injection pattern based on the calculated necessary volume of the contrast medium and the base-operation condition, and (iv) to perform the injection of contrast medium based on the injection pattern by controlling the operation of said liquid injection mechanism, wherein the injection rate of the base-operation condition is changed based on the calculated necessary volume of the contrast medium, and wherein the predetermined injection time is unchanged, for all volumes of the contrast medium, when making the injection pattern, whereby a timing of an optimum concentration of the contrast medium will be substantially unchanged for all volumes of the contrast medium.