Patent ID: 8718747

Claim:
A method for estimating contrast agent extravasation in contrast agent based perfusion imaging methods to be performed by an electronic processor, the method comprising: accessing perfusion image data comprising a signal related to contrast agent concentration as a function of time in a voxel during the first and consecutive passages of the contrast agent through the vascular system; representing the signal by a convolution, R ps ′(t) C p ′(t), of an apparent residue function, R ps ′(t), and an estimated contrast agent concentration in plasma, C p ′(t), and determining the apparent residue function R ps ′(t) by deconvolution of the signal with C p ′(t); estimating a first leakage rate constant K a from a tail part of the apparent residue function, where K a is quantifying an apparent rate of contrast agent extravasation from plasma to extravascular, extracellular space (EES); determining an extravasation corrected residue function, R corr (t), from the apparent residue function R ps ′(t) and the estimated K a , wherein the extravasation corrected residue function, R corr (t), is determined using at least one of the following algorithms: R corr ( t )= R ps ′( t )− K a R corr ( t )=1 /F ( R ps ′( t )− K a (1− k ep t )) R corr ( t )=1 /F ( R ps ′( t )− K α e −k ep t ) R corr ( t )=1 /F ( R ps ′( t )−mean[ R ps ′( t>t tp )]); where F is the tissue flow and t tp is an estimated start time of the tail part and where k ep is a second leakage rate constant which is quantifying an apparent rate of contrast agent reflux from tissue back to blood.