Computation of Hemodynamic Quantities from Angiographic Data

Abstract

Methods for computing hemodynamic quantities include: (a) acquiring angiography data from a patient; (b) calculating a flow and/or calculating a change in pressure in a blood vessel of the patient based on the angiography data; and (c) computing the hemodynamic quantity based on the flow and/or the change in pressure. Systems for computing hemodynamic quantities and computer readable storage media are described.

1 . A computer-implemented method for computing a hemodynamic quantity, the method comprising:
 acquiring angiography data from a patient at a first physiological state of the patient;   calculating, by a processor, a first flow in a blood vessel of the patient based on the angiography data, wherein the first flow corresponds to the first physiological state of the patient;   calculating, by the processor, a second flow in a blood vessel based on scaling the first flow by a flow rate scalar from the first physiological state to a second physiological state, wherein the second flow corresponds to the second physiological state of the patient that is different from the first physiological state of the patient;   computing, by the processor, the hemodynamic quantity based on the second flow; and   reporting the hemodynamic quantity.   
     
     
         2 . The computer-implemented method of  claim 1  wherein the hemodynamic quantity comprises fractional flow reserve. 
     
     
         3 . The computer-implemented method of  claim 1  wherein at least a portion of the angiography data is acquired when the patient is at rest. 
     
     
         4 . The computer-implemented method of  claim 1  wherein at least a portion of the angiography data is acquired when the patient is in a state of hyperemia. 
     
     
         5 . The computer-implemented method of  claim 1  wherein the second flow comprises hyperemic flow. 
     
     
         6 . The computer-implemented method of  claim 1  wherein the blood vessel comprises a stenosis. 
     
     
         7 . The computer-implemented method of  claim 1  further comprising calculating both the flow and a change in pressure. 
     
     
         8 . The computer-implemented method of  claim 1  wherein the angiography data is acquired only when the patient is at rest. 
     
     
         9 . The computer-implemented method of  claim 1  wherein the first physiological state comprises a rest state and wherein the second physiological state comprises a hyperemic state. 
     
     
         10 . The computer-implemented method of  claim 1  wherein the calculating of the first flow is based on movement of a contrast agent in the blood vessel. 
     
     
         11 . The computer-implemented method of  claim 1  further comprising modeling at least a portion of the blood vessel based on the angiography data. 
     
     
         12 . The computer-implemented method of  claim 1  wherein the first flow comprises a rest-state flow. 
     
     
         13 . The computer-implemented method of  claim 12  wherein calculating the second flow comprises calculating a hyperemic flow, wherein the hyperemic flow is derived from the rest-state flow. 
     
     
         14 . A computer-implemented method for computing a fractional flow reserve, the method comprising:
 acquiring angiography data from a patient at a first physiological state of the patient, wherein the acquiring comprises monitoring movement of a contrast agent through a blood vessel of the patient;   calculating, by a processor, a flow based on the angiography data, wherein the flow corresponds to a second physiological state of the patient that is different from the first physiological state of the patient, the flow calculated with a scalar applied to another flow for the first physiological state;   calculating, by the processor, a change in pressure in the blood vessel of the patient, wherein the blood vessel comprises a stenosis;   computing, by the processor, the fractional flow reserve based on the flow and the change in pressure; and   reporting the fractional flow reserve.   
     
     
         15 . A system for computing a hemodynamic quantity, the system comprising:
 a processor;   a non-transitory memory coupled to the processor;   first logic stored in the memory and executable by the processor to cause the processor to acquire angiography data from a patient at a first physiological state of the patient;   second logic stored in the memory and executable by the processor to cause the processor to calculate a flow as a weighted flow based on the angiography data, wherein the flow corresponds to a second physiological state of the patient that is different from the first physiological state of the patient;   third logic stored in the memory and executable by the processor to cause the processor to calculate a change in pressure in a blood vessel of the patient based on the angiography data; and   fourth logic stored in the memory and executable by the processor to cause the processor to compute the hemodynamic quantity based on the flow and/or the change in pressure; and   a display configured to output the hemodynamic quantity.   
     
     
         16 . The system of  claim 15  wherein the hemodynamic quantity comprises fractional flow reserve. 
     
     
         17 . The system of  claim 15  further comprising fifth logic stored in the memory and executable by the processor to cause the processor to monitor movement of a contrast agent in the blood vessel. 
     
     
         18 . The system of  claim 15  further comprising fifth logic stored in the memory and executable by the processor to cause the processor to model at least a portion of the blood vessel based on the angiography data. 
     
     
         19 . A non-transitory computer readable storage medium having stored therein data representing instructions executable by a programmed processor for computing a hemodynamic quantity, the storage medium comprising instructions for:
 acquiring angiography data from a patient at a first physiological state of the patient;   calculating a flow based on the angiography data, wherein the flow corresponds to a second physiological state of the patient that is different from the first physiological state of the patient, the flow being derived by weighting another flow calculated for the first physiological state;   calculating a change in pressure in a blood vessel of the patient based on the angiography data;   computing the hemodynamic quantity based on the flow and/or the change in pressure; and   outputting the hemodynamic quantity.