Identification of patients who will benefit from specific therapeutic procedure requires the accurate assessment of the severity of stenoses, their geometry and spatial orientation. Most therapeutic decisions are currently based on information obtained through digital subtraction angiography. Standard angiographic images are not providing angiographers with sufficient information needed to make therapeutic decisions. The long-term goal of this five year project is to develop a three-dimensional (3-D) tomographic (called volume tomographic) digital angiography imaging technique to provide angiographers with useful 3-D vascular images needed for diagnostic and therapeutic decisions. Volume tomographic digital angiography (VTDA) combines volume tomographic imaging principles with those of digital angiography. VTDA requires only a single contrast injection and volume scan to provide a true 3-D description of vascular anatomy and stenoses in head and neck. This VDTA technique will have a strong clinical impact since it will simplify the procedure, and reduce contrast media dose, total x-ray dose and the procedure time, while supplying the angiographer with direct, umbiguous and accurate measurement of the severity of the stenoses, their geometry, and spatial orientation. VTDA will be developed and validated through computer simulation, phantom, and animal studies performed on a rotational volume tomographic imager that uses an image intensifier coupled to a charge-coupled device (CCD) as a detector. Specifically, the aim of the proposed research are: 1) to perform studies on optimization of VTDA through computer simulation; 2) to implement optimized contrast agent injection protocols and to develop acquisition protocols and vascular reconstruction algorithms; 3) to produce a prototype rotational volume tomographic imager by replacing the linear detector of an available CT scanner with a 2-D detector; 4) to perform phantom studies and optimize the system performance; and 5) to use the prototype imager for animal experiments as a prelude to human studies.
