System and method for four dimensional angiography and fluoroscopy
A method for generating time-resolved 3D medical images of a subject by imparting temporal information from a time-series of 2D medical images into 3D images of the subject. Generally speaking, this is achieved by acquiring image data using a medical imaging system, generating a time-series of 2D images of a ROI from at least a portion of the acquired image data, reconstructing a 3D image substantially without temporal resolution from the acquired image data, and selectively combining the time series of 2D images with the 3D image.
1. A method for producing time-resolved, three-dimensional fluoroscopic images of an interventional device superimposed on a three-dimensional (3D) vascular roadmap, the method comprising:
selecting a 3D vascular roadmap;
generating, via a bi-plane fluoroscopic system, a time-series of fluoroscopic images of an interventional device obtained at a plurality of bi-plane source-detector gantry angles;
forming a series of 3D fluoroscopic volumes using the time-series of fluoroscopic images by, for each 3D fluoroscopic volume:
projecting pixels in two or more of the fluoroscopic images onto the 3D vascular roadmap; and
multiplying voxel values of the 3D vascular roadmap with attenuation values of corresponding projected pixels from the two or more fluoroscopic images;
forming a time-series of volumes including the interventional device and static vascular information obtained from the 3D vascular roadmap; and
displaying ongoing fluoroscopic images superimposed on the 3D vascular roadmap from arbitrary directions by forming maximum intensity projections through the time-series of volumes.
2. The method of claim 1 , wherein multiplying voxel values of the 3D vascular roadmap with attenuation values of corresponding projected pixels includes multiplying a voxel value for a voxel of the 3D vascular roadmap with attenuation values of pixels projected onto that voxel.
3. The method of claim 1 , wherein the time-series of fluoroscopic images is generated by subtracting fluoroscopic images separated by a selected number of time-frames.
4. The method of claim 3 , wherein the subtracted fluoroscopic images are sequentially combined with the 3D vascular roadmap.
5. The method of claim 4 , wherein a composite device path history image is formed by adding the time-series of fluoroscopic images sequentially combined with the 3D vascular roadmap over a selected time interval.
6. The method of claim 5 , wherein the selected time interval can be updated.
7. The method of claim 1 , further comprising:
searching a range of horizontal and vertical magnifications;
for each magnification, performing a spatially displaced block search to minimize the sum of absolute differences between projections through the vascular roadmap and displaced fluoroscopic time frames.
8. The method of claim 7 , further comprising iteratively employing a block matching technique that analyzes large blocks before analyzing smaller blocks.
9. The method of claim 8 , further comprising determining a direction of movement of the interventional device by calculating a sum of pixel values within a block as a test object similar in size to the interventional device is rotated through the block.
10. The method of claim 9 , further comprising applying a linear convolution filter along the direction of movement of the interventional device.
11. The method of claim 1 , wherein the interventional device is at least one of a catheter or a coil.
12. The method of claim 1 , further comprising:
scanning the fluoroscopic images of the interventional device point-by-point;
determining a direction in which a maximum linear sum occurs over a number of pixels; and
applying a linear filter in the determined direction.
13. The method of claim 1 wherein the 3D vascular roadmap is provided by a four-dimensional digital subtraction angiography time frame.
14. The method of claim 1 wherein the 3D vascular roadmap is provided by 3D rotational DSA data.
15. A method for producing time-resolved, three-dimensional fluoroscopic images of an interventional device superimposed on a three-dimensional (3D) vascular roadmap, the method comprising:
selecting a 3D vascular roadmap;
generating, via a single-plane fluoroscopic system, a subtracted time-series of fluoroscopic images of an interventional device obtained at a single source-detector gantry angle;
combining the subtracted time-series of fluoroscopic images into a three-dimensional vascular space including a series of 3D fluoroscopic volumes by, for each 3D fluoroscopic volume:
projecting pixels in one or more of the subtracted fluoroscopic images onto the 3D vascular roadmap; and
multiplying voxel values of the 3D vascular roadmap with attenuation values of corresponding projected pixels from the one or more subtracted fluoroscopic images; and
displaying ongoing fluoroscopic images superimposed on the 3D vascular roadmap from arbitrary directions by forming maximum intensity projections through the time-series of volumes.
16. The method of claim 15 , wherein a position of the interventional device in a direction of multiplying rays is substantially in a center of a vessel of a subject under examination.
17. The method of claim 15 , wherein the interventional device is at least one of a catheter or a coil.
18. The method of claim 15 wherein the 3D vascular roadmap is provided by a four-dimensional digital subtraction angiography time frame.
19. The method of claim 15 wherein the 3D vascular roadmap is provided by 3D rotational DSA data.