document: Computation of unmeasured third-generation VCT views from measured views We compute unmeasured cone-beam projections from projections measured by a third-generation helical volumetric computed tomography system by solving a characteristic problem for an ultrahyperbolic differential equation -LSB- John -LRB- 1938 -RRB- -RSB- . By working in the Fourier domain , we convert the second-order PDE into a family of first-order ordinary differential equations . A simple first-order integration is used to solve the ODES
doc_bio_tags: O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O