A fluorescence-endoscope apparatus that radiates excitation light onto biological tissue containing a plurality of types of fluorescent components, whose maximum-fluorescence wavelengths are different and whose fluorescence wavelengths overlap in at least parts of the wavelength ranges, that acquires a plurality of types of images of fluorescence generated by the biological tissue, and that displays, in a separated manner, the plurality of types of fluorescent components present in the biological tissue using the acquired fluorescence images, comprising:
- a light source portion that emits at least one type of excitation light that excites the plurality of types of fluorescent components;
- a fluorescence image capturing unit that acquires the images of fluorescence generated by the biological tissue for every n types [where, m≦n] of wavelength λ1 to wavelength λn;
- a fluorescence-spectrum storage unit that records fluorescence spectra of m types [where, 2≦m] of individual fluorescent component 1 to fluorescent component m present in the biological tissue at normalized densities under reference exposure conditions;
- a fluorescent-component-density computation unit that obtains densities of the individual fluorescent components present in the biological tissue for all pixels in the fluorescence images by performing computation using the fluorescence spectra of the individual fluorescent component 1 to fluorescent component m at the normalized densities under the reference exposure conditions that are stored in the fluorescence-spectrum storage unit and the fluorescence images for every wavelength λ1 to wavelength λn acquired by the fluorescence image capturing unit;
- a fluorescence-image combining portion that forms distribution images of the individual fluorescent components on the basis of the densities of the individual fluorescent components obtained by the fluorescent-component-density computation unit, assigns predetermined colors corresponding to the individual fluorescent components to the formed distribution images of the individual fluorescent components, and combines the distribution images to which the predetermined colors are assigned into one image;
- and
- an image display portion that displays the image that has been combined by the fluorescence-image combining portion,
- wherein, when a1(λ1) to a1(λn) to am(λ1) to am(λn) are defined as coefficients at the wavelength λ1 to wavelength λn of the fluorescent component 1 to fluorescent component m at the individual normalized densities under the reference exposure conditions, which are obtained from the fluorescence spectra, stored in the fluorescence-spectrum storage unit, of the fluorescent component 1 to fluorescent component m at the individual normalized densities under the reference exposure conditions, Iall(λ1) to Iall(λn) are defined as intensities of the fluorescence images at the wavelength λ1 to wavelength λn acquired by the fluorescence image capturing unit, and D1 to Dm are defined as the densities of the fluorescent components 1 to fluorescent component m, the fluorescent-component-density computation unit calculates, for all pixels, the density D1 of the fluorescent component 1 to the density Dm of the fluorescent component m in each pixel in the fluorescence images using Equation (1) below, and
- wherein the fluorescent-component-density computation unit:
- checks if the reference exposure conditions of an exposure condition item have been changed;
- and
- if a value of a predetermined exposure condition item has been changed when the fluorescence image at at least one wavelength λx among the wavelength λ1 to wavelength λn is acquired by the fluorescence image capturing unit, in accordance with the change,
- when the density D1 of the fluorescent component 1 to the density Dm of the fluorescent component m are calculated using Equation (1), changes the coefficients a1(λx) to am(λx) at the wavelength λx of the fluorescent component 1 to fluorescent component m at the normalized density under the reference exposure conditions using the ratio of the value of the changed predetermined exposure condition item to the value of the predetermined exposure condition item under the reference exposure conditions when the fluorescence image at the wavelength λx is acquired by the fluorescence image capturing unit:
- [
- Expression
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- Equation (1).