A method for medical imaging in TOF-PET tomography, comprising the following steps: - introducing an object containing a positron-emitting radioisotope into a diagnostic chamber of a tomograph, - recording gamma quanta emitted from an imaged part of the object by means of the tomograph, - attributing recorded events to 2γ and 3γ annihilation subgroups,-reconstructing a 2γ image of the imaged part of the object, - reconstructing a 3γ image of the imaged part of the object, characterized in that, the method further comprises the steps of: - normalising the 2γ image to obtain a normalised 2γ image so that the integral of the values over all voxels of the normalized 2γ image is equal to the total number of 2γ annihilations which have occurred in the imaged volume, - normalising the 3γ image to obtain a normalised 3γ image so that the integral of the values over all voxels of the normalised 3γ image is equal to the total number of 3γ annihilations which have occurred in the imaged volume, - determining a value of a morphometric indicator δ 3γ for every voxel of the imaged part of the object based on the following dependence: δ 3 γ = ƒ 3 γ 2 γ t − ƒ 3 γ 2 γ r ƒ 3 γ 2 γ r × 1000 o oo where: (f 3γ2γ) t is a ratio of count number of annihilations with 3γ emission to a count number of annihilations with 2γ emission, calculated for every voxel of the imaged part of the object based on the normalized 2γ image and the normalized 3γ image, and (f 3γ2γ) r is a ratio of count number of annihilations with 3γ emission to a count number of annihilations with 2γ emission in a reference material, - visualising the morphometric image of the imaged part of the object, having voxels based on the determined values of the morphometric indicators δ 3γ. - introducing an object containing a positron-emitting radioisotope into a diagnostic chamber of a tomograph, - recording gamma quanta emitted from an imaged part of the object by means of the tomograph, - attributing recorded events to 2γ and 3γ annihilation subgroups,-reconstructing a 2γ image of the imaged part of the object, - reconstructing a 3γ image of the imaged part of the object, - normalising the 2γ image to obtain a normalised 2γ image so that the integral of the values over all voxels of the normalized 2γ image is equal to the total number of 2γ annihilations which have occurred in the imaged volume, - normalising the 3γ image to obtain a normalised 3γ image so that the integral of the values over all voxels of the normalised 3γ image is equal to the total number of 3γ annihilations which have occurred in the imaged volume, - determining a value of a morphometric indicator δ 3γ for every voxel of the imaged part of the object based on the following dependence: δ 3 γ = ƒ 3 γ 2 γ t − ƒ 3 γ 2 γ r ƒ 3 γ 2 γ r × 1000 o oo where: (f 3γ2γ) t is a ratio of count number of annihilations with 3γ emission to a count number of annihilations with 2γ emission, calculated for every voxel of the imaged part of the object based on the normalized 2γ image and the normalized 3γ image, and (f 3γ2γ) r is a ratio of count number of annihilations with 3γ emission to a count number of annihilations with 2γ emission in a reference material, - visualising the morphometric image of the imaged part of the object, having voxels based on the determined values of the morphometric indicators δ 3γ.