/* fwdmodel_asl_dynangio.cc -kinetic curve modelling for ASL Dynamic Angio data Michael Chappell, IBME & FMRIB Image Analysis Group Copyright (C) 2010 University of Oxford */ /* Part of FSL - FMRIB's Software Library http://www.fmrib.ox.ac.uk/fsl fsl@fmrib.ox.ac.uk Developed at FMRIB (Oxford Centre for Functional Magnetic Resonance Imaging of the Brain), Department of Clinical Neurology, Oxford University, Oxford, UK LICENCE FMRIB Software Library, Release 5.0 (c) 2012, The University of Oxford (the "Software") The Software remains the property of the University of Oxford ("the University"). 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Contact details are: innovation@isis.ox.ac.uk quoting reference DE/9564. */ #include "fwdmodel_asl_dynangio.h" #include #include #include #include "newimage/newimageall.h" #include "miscmaths/miscprob.h" using namespace NEWIMAGE; #include "easylog.h" string DynAngioFwdModel::ModelVersion() const { return "$Id: fwdmodel_asl_dynangio.cc,v 1.2 2011/03/10 13:56:06 chappell Exp $"; } void DynAngioFwdModel::HardcodedInitialDists(MVNDist& prior, MVNDist& posterior) const { Tracer_Plus tr("DynAngioFwdModel::HardcodedInitialDists"); assert(prior.means.Nrows() == NumParams()); SymmetricMatrix precisions = IdentityMatrix(NumParams()) * 1e-12; // Set priors // abv prior.means(1) = 0; precisions(1,1) = 1e-12; // transit delay prior.means(2) = 0.1; precisions(2,2) = 10; // bolus duration prior.means(3) = seqtau; if (taufix) precisions(3,3) = 1e99; else precisions(3,3) = 10; // T1b prior.means(4) = t1b; precisions(4,4) = 100; //dispersion parameters //default to 0 and known prior.means(disp_index()) = 0; prior.means(disp_index()+1) = 0; precisions(disp_index(),disp_index()) = 1e12; precisions(disp_index()+1,disp_index()+1) = 1e12; if (disptype=="gamma") { prior.means(disp_index()) = 1.1; //-1;//0.05; prior.means(disp_index()+1) = 0.1; //1.1; //0.7; //2; precisions(disp_index(),disp_index()) = 1; //10; //400; precisions(disp_index()+1,disp_index()+1) = 100; //1; } if (disptype=="gvf") { prior.means(disp_index()) = 1.1;//0.05; prior.means(disp_index()+1) = 0.7; precisions(disp_index(),disp_index()) = 1; //400; precisions(disp_index()+1,disp_index()+1) = 10; } if (disptype=="gauss") { prior.means(disp_index()) = -1.6; precisions(disp_index(),disp_index()) = 1; } if (disptype=="sgauss") { prior.means(disp_index()) = -1.4; precisions(disp_index(),disp_index()) = 1; } if (disptype=="gallichan") { prior.means(disp_index()) = 0.2; precisions(disp_index(),disp_index()) = 0.1; } prior.means(7) = 0; precisions(7,7) = 0.1; // Set precsions on priors prior.SetPrecisions(precisions); // Set initial posterior posterior = prior; // For parameters with uniformative prior chosoe more sensible inital posterior posterior.means(1) = 1; precisions(1,1) = 1; // for dispersion parameters - initialise to a realtively non dispersed case if (disptype=="gamma" || disptype=="gvf") { prior.means(disp_index()) = 5; prior.means(disp_index()) = 1; } posterior.SetPrecisions(precisions); } void DynAngioFwdModel::Evaluate(const ColumnVector& params, ColumnVector& result) const { Tracer_Plus tr("DynAngioFwdModel::Evaluate"); // ensure that values are reasonable // negative check ColumnVector paramcpy = params; for (int i=1;i<=NumParams();i++) { if (params(i)<0) { paramcpy(i) = 0; } } // sensible limits on transit times if (params(2)>timax-0.2) { paramcpy(2) = timax-0.2; } // parameters that are inferred - extract and give sensible names float abv; float delt; float tau; float T_1b; bool outresult=true; abv = params(1); delt = params(2); tau = params(3); T_1b = params(4); float floor; floor = params(7); if (abv < 0 || delt<0 || tau < 0 || T_1b < 0 ) { //delt=0; outresult=true; } if (outresult) { // Look-locker readout T_1b = 1/( 1/T_1b - log(cos(FA))/dti); //assume that all the blood has seen the small FAs // deal with different dispersion models ColumnVector kcblood(tis.Nrows()); // generate the kinetic curves if (disptype=="none") { kcblood=kcblood_nodisp(tis,delt,tau,T_1b,false); //cout << kcblood << endl; } else if (disptype=="gamma") { float p; float s; s = exp( params(disp_index()) ); //float k=exp(params(disp_index()+1));; //p = (k-1)/s; //possibly define that parameter as (k-1) ? p = params(disp_index()+1); if (p<0) p=0; kcblood=kcblood_gammadisp(tis,delt,tau,T_1b,s,p,false); //cout << kcblood << endl; } else if (disptype=="gvf") { float p; float s; //float sp = exp(params(disp_index())); s = exp( params(disp_index()) ); //if (sp>10) sp=10; p = params(disp_index()+1); //sp/s; kcblood=kcblood_gvf(tis,delt,T_1b,s,p,false); //cout << kcblood << endl; } else if (disptype=="gauss") { float sig; sig = exp( params(disp_index()) ); // we will only have diserpsion SD (leading edge) // assume trailing edge is related to leading edge as Hrabe did float sig2; if (delt > 0) { sig2 = sig*sqrt( (delt+tau)/delt ); } else sig2 = sig; //cout << sig << endl; kcblood = kcblood_gaussdisp(tis,delt,tau,T_1b,sig,sig2,false); //cout << kcblood.t() << endl; } else if (disptype=="sgauss") { float k; k = exp( params(disp_index()) ); kcblood = kcblood_spatialgaussdisp(tis,delt,tau,T_1b,k,false); } else if (disptype=="gallichan") { float xV; xV = params(disp_index()); kcblood = kcblood_gallichan(tis,delt,tau,T_1b,xV,false); } else { throw Exception("Unrecognised dispersion model "); } // Nan catching bool cont=true; int it=1; while (cont) { if (isnan(kcblood(it)) || isinf(kcblood(it)) ) { LOG << "Warning NaN or Inf in kcblood" << endl; LOG << "params: " << params.t() << endl; LOG << "kcblood: " << kcblood.t() << endl; cont =false; kcblood=1e12; } it++; if (it>kcblood.Nrows()) cont=false; } // assemble the result result = floor + abv*kcblood; } else { result.ReSize(tis.Nrows()); result = 0; } return; } DynAngioFwdModel::DynAngioFwdModel(ArgsType& args) { string scanParams = args.ReadWithDefault("scan-params","cmdline"); if (scanParams == "cmdline") { // specify command line parameters here //dispersion model disptype=args.ReadWithDefault("disp","gamma"); //repeats = convertTo(args.Read("repeats")); // number of repeats in data t1b = convertTo(args.ReadWithDefault("t1b","1.66")); seqtau = convertTo(args.ReadWithDefault("tau","1000")); //bolus length as set by sequence (default of 1000 is effectively infinite // special options taufix = args.ReadBool("taufix"); // Deal with tis tis.ReSize(1); //will add extra values onto end as needed tis(1) = atof(args.Read("ti1").c_str()); while (true) //get the rest of the tis { int N = tis.Nrows()+1; string tiString = args.ReadWithDefault("ti"+stringify(N), "stop!"); if (tiString == "stop!") break; //we have run out of tis // append the new ti onto the end of the list ColumnVector tmp(1); tmp = convertTo(tiString); tis &= tmp; //vertical concatenation } timax = tis.Maximum(); //dtermine the final TI //determine the TI interval (assume it is even throughout) dti = tis(2)-tis(1); float fadeg = convertTo(args.ReadWithDefault("fa","30")); FA = fadeg * M_PI/180; // add information about the parameters to the log LOG << "Inference using Dynamic Angio model" << endl; LOG << "TIs: "; for (int i=1; i <= tis.Nrows(); i++) LOG << tis(i) << " "; LOG << endl; } else throw invalid_argument("Only --scan-params=cmdline is accepted at the moment"); } void DynAngioFwdModel::ModelUsage() { cout << "To be added" << endl ; } void DynAngioFwdModel::DumpParameters(const ColumnVector& vec, const string& indent) const { } void DynAngioFwdModel::NameParams(vector& names) const { names.clear(); names.push_back("aBV"); names.push_back("delt"); names.push_back("tau"); names.push_back("T_1b"); names.push_back("disp1"); names.push_back("disp2"); } void DynAngioFwdModel::SetupARD( const MVNDist& theta, MVNDist& thetaPrior, double& Fard) { } void DynAngioFwdModel::UpdateARD( const MVNDist& theta, MVNDist& thetaPrior, double& Fard) const { }