Method for three-dimensional digital subtraction angiography and apparatus

#The present patent document claims the benefit of European Patent Application No. 18191913.5, filed Aug. 31, 2018, which is also hereby incorporated by reference.

#The disclosure relates to a method for producing a high-resolution three-dimensional digital subtraction angiography image of an examination object as well as an apparatus for performing the method.

#“Simple” digital subtraction angiography (DSA) is used for the examination of blood vessels. In this procedure, multiple temporally successive x-ray images of a body part to be examined, (e.g., a brain), are produced while a contrast agent is being injected. This results in one x-ray image without contrast agent, (also known as the mask image), and further x-ray images with a distribution of contrast agent. The digital mask image is subtracted from the subsequent x-ray images. What remain are the parts that differ, e.g., the blood vessels.

#Advantageous embodiments of the disclosure are explained in greater detail below in the drawings, without thereby limiting the disclosure to these exemplary embodiments. In the drawings:

#FIG. 1 depicts an example of a sequence of a method for producing a 3D DSA.

#FIG. 2 depicts a view of an example of C-arm x-ray device for performing a method as disclosed herein.

#FIG. 1 depicts a sequence of a method for digital 3D subtraction angiography, in which both the data set for the mask run and the data set for the fill run are recorded directly. Alternatively, the data sets may also be retrieved from a storage unit or data library after having previously been recorded and stored.

#Digital 3D subtraction angiography (3D DSA) allows a high-resolution representation of contrast-enhanced vascular trees, e.g. cerebral vessels or coronary vessels, as 3D volumes.

#In act 10, using a C-arm x-ray device having an imaging system with a C-arm and designed for recording three-dimensional x-ray images, a data set is recorded during a three-dimensional rotational run of the imaging system around an examination object without administration of contrast agent (e.g., mask run). An exemplary C-arm x-ray device 1 is depicted in FIG. 2. An x-ray source 3 and a planar x-ray detector 4 are arranged on the C-arm 2 and the C-arm 2 is configured such that it may perform a rotational movement around the examination object while recording a large number of projection images from different projection directions. This type of imaging with subsequent reconstruction is referred to, e.g., as cone-beam CT or also as DynaCT. The C-arm x-ray device is actuated by a control unit 5.