Methods and systems for dynamic coronary roadmapping

Abstract

Methods and systems are provided for dynamically visualizing an object of interest that includes part of the vasculature of a patient, which employ a 3D model of the object to generate at least one roadmap that includes information that characterizes properties of the object (such as centerlines, contours, and an image mask. Reference location(s) corresponding to the roadmap(s) are determined for an interventional device used to treat the object. In an online phase, non-contrast-enhanced x-ray image data of the object are obtained and processed to determine location of the interventional device in the image data, and a particular roadmap is selected or accessed. The reference location corresponding to the particular roadmap and the determined location of interventional device are used to transform the particular roadmap. A visual representation of the transformed roadmap is overlaid on the image data for display.

1 . A method for generating an image of an object of interest of a patient, the object of interest comprising part of the vasculature of the patient, the method comprising:
 i) generating a three-dimensional (3D) model of the object of interest from 3D image data acquired using a 3D angiographic imaging modality;   ii) using the 3D model to generate at least one roadmap that includes information that characterizes properties of the object of interest, the information including at least one of centerlines, contours, and an image mask of the object of interest;   iii) determining a reference location for a tip of an interventional device being used in a procedure to treat the object of interest, the reference location corresponding to the at least one roadmap;   iv) obtaining non-contrast-enhanced x-ray image data of the object of interest, wherein the non-contrast-enhanced x-ray image data is acquired using an x-ray imaging modality without a contrast agent and the interventional device is present in the non-contrast-enhanced x-ray image data;   v) determining location of the tip of the interventional device in the non-contrast-enhanced x-ray image data;   vi) selecting or accessing a particular roadmap as generated in ii);   vii) using the reference location of iii) that corresponds to the particular roadmap and the location of the tip of the interventional device determined in v) to transform the particular roadmap; and   viii) overlaying a visual representation of the transformed roadmap of vii) on the non-contrast-enhanced x-ray image data for display.   
     
     
         2 . A method according to  claim 1 , wherein:
 the least one roadmap comprises at least one two-dimensional roadmap.   
     
     
         3 . A method according to  claim 1 , wherein:
 the least one roadmap comprises at least one 3D roadmap.   
     
     
         4 . A method according to  claim 1 , further comprising:
 obtaining contrast-enhanced x-ray image data of the object of interest, wherein the contrast-enhanced x-ray image data is acquired using an x-ray imaging modality with a contrast agent and the interventional device is present in the contrast-enhanced x-ray image data, wherein contrast-enhanced x-ray image data covers at least one cardiac cycle of the patient;   wherein the operations of ii) use the 3D model and the contrast-enhanced x-ray image data to generate a sequence of 3D roadmaps of the object of interest over time that covers multiple phases of at least one cardiac cycle of the patient;   wherein the operations of iii) determine reference locations that correspond to the sequence of 3D roadmaps of the object of interest over time;   wherein the operations of vi) select a particular 3D roadmap from the sequence of 3D roadmaps over time; and   wherein the operations of vii) use the reference location of iii) that corresponds to the particular 3D roadmap and the location of the tip of the interventional device as determined in v) to transform the particular 3D roadmap.   
     
     
         5 . A method according to  claim 4 , further comprising:
 acquiring an ECG signal while acquiring the non-contrast-enhanced x-ray image data, and processing the ECG signal to determine a phase of the cardiac cycle of the patient that corresponds to the non-contrast-enhanced x-ray image data; and   selecting the particular 3D roadmap in vi) by matching the phase of the cardiac cycle of the patient for the non-contrast-enhanced x-ray image data to the phase of the cardiac cycle of the patient for the particular selected 3D roadmap.   
     
     
         6 . A method according to  claim 1 , wherein:
 the 3D model of i) includes 3D vessel centerlines and 3D surface contours representing at least one of luminal vessel surfaces, plaque, and 3D masks.   
     
     
         7 . A method according to  claim 1 , wherein:
 the 3D angiographic imaging modality of i) is selected from the group consisting of computed tomography (CT), X-ray rotational angiography, 3D Ultrasound, or magnetic resonance imaging (MRI).   
     
     
         8 . A method according to  claim 4 , further comprising:
 processing the contrast-enhanced x-ray image data of the object of interest to determine a phase of the cardiac cycle of the patient for an image frame and associating the phase of the cardiac cycle to a 3D roadmap corresponding to the image frame.   
     
     
         9 . A method according to  claim 4 , wherein:
 the sequence of 3D roadmaps over time are derived from the 3D model of i) and one x-ray angiographic image sequence of the object of interest acquired with a contrast agent; or   the sequence of 3D roadmaps over time are derived from the 3D model of i) and two x-ray angiographic image sequences of the object of interest acquired with a contrast agent.   
     
     
         10 . A method according to  claim 4 , wherein:
 the sequence of 3D roadmaps over time are defined in a 3D coordinate system.   
     
     
         11 . A method according to  claim 4 , wherein:
 the 3D model of i) includes 3D surface contours representing luminal vessel surfaces and plaque; and   the sequence of 3D roadmaps over time are defined in a 3D coordinate system and include information characterizing vessel contours and plaque.   
     
     
         12 . A method according to  claim 1 , wherein:
 the operations of vii) apply a transformation to the particular roadmap in order to compensate for motion.   
     
     
         13 . A method according to  claim 12 , wherein:
 the motion includes breathing motion and/or cardiac motion and/or patient motion and/or table motion.   
     
     
         14 . A method according to  claim 1 , wherein:
 the transformation of vii) comprises a rigid transformation or a non-rigid transformation to the particular roadmap based on a displacement obtained from the reference location corresponding to the particular roadmap and the location of the tip of the interventional device as determined in v).   
     
     
         15 . A method according to  claim 1 , wherein:
 the transformation of vii) is based on the viewpoint used to acquire the non-contrast-enhanced x-ray image data.   
     
     
         16 . A method according to  claim 1 , wherein:
 the visual representation of the transformed roadmap is generating by a) projecting the overlay of the transformed roadmap onto the non-contrast-enhanced x-ray image data using a transparent mode, and/or b) projecting boundaries of the transformed roadmap onto the non-contrast-enhanced x-ray image data.   
     
     
         17 . A method according to  claim 1 , wherein:
 the visual representation of the transformed roadmap is configured to not obscure any instrument used to treat the object of interest.   
     
     
         18 . A method according to  claim 1 , wherein:
 the non-contrast-enhanced x-ray image data is derived by subtraction of a baseline image.   
     
     
         19 . A method according to  claim 1 , wherein:
 the operations of iv) to viii) are repeated for successive frames of a live image sequence acquired without a contrast agent.   
     
     
         20 . A method according to  claim 1 , wherein:
 the interventional device is selected from the group consisting of a guiding catheter, a guide wire, or other intraluminal device or instrument.   
     
     
         21 . A method according to  claim 1 , further comprising:
 displaying the overlay of the visual representation of the transformed roadmap of the object of interest on the non-contrast-enhanced x-ray image data.   
     
     
         22 . A method according to  claim 1 , wherein:
 the object of interest comprises part of the coronary tree, blood vessels and/or heart of the patient.   
     
     
         23 . A system for generating an image of an object of interest of a patient, the object of interest comprising part of the vasculature of the patient, the system comprising:
 at least one processor that, when executing program instructions stored in memory, is configured to perform the method of  claim 1 .   
     
     
         24 . A system according to  claim 23 , further comprising:
 an imaging acquisition subsystem configured to acquire the non-contrast-enhanced x-ray image data, wherein the imaging acquisition subsystem uses an x-ray imaging modality.   
     
     
         25 . A system according to  claim 23 , further comprising:
 a display subsystem configured to display the overlay of the visual representation of the transformed roadmap of the object of interest on the non-contrast-enhanced x-ray image data.   
     
     
         26 . A non-transitory program storage device tangibly embodying a program of instructions that are executable on a machine to perform the operations of  claim 1  for generating an image of an object of interest of a patient, wherein the object of interest comprises part of the vasculature of the patient.