Procedures for simulating PET time-activity curves. More...

#include "libtpcmodel.h"

Functions
int	simC3s (double t, double ca, int nr, double k1, double k2, double k3, double k4, double k5, double k6, double ct, double cta, double ctb, double ctc)

int	simC3p (double t, double ca, int nr, double k1, double k2, double k3, double k4, double k5, double k6, double ct, double cta, double ctb, double ctc)

int	simC3vs (double t, double ca, double cb, int nr, double k1, double k2, double k3, double k4, double k5, double k6, double f, double vb, double fa, double cpet, double cta, double ctb, double ctc, double ctab, double *ctvb)

int	simC3vp (double t, double ca, double cb, int nr, double k1, double k2, double k3, double k4, double k5, double k6, double f, double vb, double fa, double cpet, double cta, double ctb, double ctc, double ctab, double *ctvb)

int	simC2l (double t, double ca, int nr, double k1, double k2, double k3, double kLoss, double ct, double cta, double *ctb)

int	simC2vl (double t, double ca, double cb, int nr, double k1, double k2, double k3, double kL, double f, double vb, double fa, double cpet, double cta, double ctb, double ctab, double ctvb)

int	simC3vpKLoss (double t, double ca, double cb, int nr, double k1, double k2, double k3, double k4, double k5, double k6, double kLoss, double f, double vb, double fa, double cpet, double cta, double ctb, double ctc, double ctab, double *ctvb)

int	simRTCM (double t, double cr, int nr, double R1, double k2, double k3, double k4, double ct, double cta, double *ctb)

int	simSRTM (double t, double cr, int nr, double R1, double k2, double BP, double *ct)

int	simTRTM (double t, double cr, int nr, double R1, double k2, double k3, double *ct)

int	simHuangmet (double t, double ctot, int nr, double k01, double k12, double k21, double k03, double k34, double k43, double c0, double c1, double *c3)

int	simTPCMOD0009c (double t, double ctot, int nr, double km, double k1m, double k2m, double k3m, double k4m, double ca, double cm)

int	simMBF (double t, double ci, int nr, double k1, double k2, double Vfit, double *ct)

int	simC1 (double t, double ca, int nr, double k1, double k2, double *ct)

int	simC3DIvs (double t, double ca1, double ca2, double cb, int nr, double k1, double k2, double k3, double k4, double k5, double k6, double k1b, double k2b, double f, double vb, double fa, double scpet, double sct1, double sct2, double sct3, double sct1b, double sctab, double *sctvb)

int	simC4DIvp (double t, double ca1, double ca2, double cb, int nr, double k1, double k2, double k3, double k4, double k5, double k6, double k7, double km, double k1b, double k2b, double f, double vb, double fa, double scpet, double sct1, double sct2, double sct3, double sct1b, double sctab, double *sctvb, int verbose)

int	simC4DIvs (double t, double ca1, double ca2, double cb, int nr, double k1, double k2, double k3, double k4, double k5, double k6, double k7, double km, double k1b, double k2b, double f, double vb, double fa, double scpet, double sct1, double sct2, double sct3, double sct1b, double sctab, double *sctvb, int verbose)

int	simDispersion (double x, double y, int n, double tau1, double tau2, double *tmp)

int	simOxygen (double t, double ca1, double ca2, double ca1i, double ca2i, const int n, const double k1a, const double k2a, const double km, const double k1b, const double k2b, const double vb, const double fa, double scpet, double sct1, double sct2, double sctab, double sctvb1, double sctvb2, double scvb1, double *scvb2, const int verbose)

Detailed Description

Procedures for simulating PET time-activity curves.

Author: Vesa Oikonen

Todo: Remove setting of small values to zero, and add instead a separate function to do that for whole DFT with user-defined limit.

Definition in file simulate.c.

Function Documentation

◆ simC1()

int simC1	(	double *	t,
		double *	ca,
		int	nr,
		double	k1,
		double	k2,
		double *	ct )

Simulates tissue TAC using 1 tissue compartment model plasma TAC, at plasma TAC times.

Memory for ct must be allocated in the calling program.

The units of rate constants must be related to the time unit; 1/min and min, or 1/sec and sec.

Returns: Function returns 0 when successful, else a value >= 1.

See also: simC3s, simC3p, simC3vs, simC3vp, simC2l, simC2vl, simC3vpKLoss, simRTCM, simSRTM, simTRTM, simHuangmet, simTPCMOD0009c, simMBF, simC3DIvs, simC4DIvp, simC4DIvs, simDispersion, simOxygen

Parameters

t	Array of time values
ca	Array of arterial activities
nr	Number of values in TACs
k1	Rate constant of the model
k2	Rate constant of the model
ct	Pointer for TAC array to be simulated; must be allocated

Definition at line 1317 of file simulate.c.

  {
  int i;
  double dt2;
  double cai, ca_last, t_last;
  double ct1, ct1_last;
  double ct1i, ct1i_last;
 
 
  /* Check for data */
  if(nr<2) return 1;
  if(ct==NULL) return 2;
 
  /* Check actual parameter number */
  if(k1<0.0) return 3;
 
  /* Calculate curves */
  t_last=0.0; if(t[0]<t_last) t_last=t[0]; 
  cai=ca_last=0.0;
  ct1_last=ct1i_last=0.0;
  ct1=ct1i=0.0;
  for(i=0; i<nr; i++) {
    /* delta time / 2 */
    dt2=0.5*(t[i]-t_last);
    /* calculate values */
    if(dt2<0.0) {
      return 5;
    } else if(dt2>0.0) {
      /* arterial integral */
      cai+=(ca[i]+ca_last)*dt2;
      /* tissue compartment and its integral */
      ct1 = (k1*cai - k2*(ct1i_last+dt2*ct1_last)) / (1.0 + dt2*k2);
      ct1i = ct1i_last + dt2*(ct1_last+ct1);
    }
    /* copy values to argument arrays; set very small values to zero */
    ct[i]=ct1; if(fabs(ct[i])<1.0e-12) ct[i]=0.0;
    /* prepare to the next loop */
    t_last=t[i]; ca_last=ca[i];
    ct1_last=ct1; ct1i_last=ct1i;
  }
 
  return 0;
}

Referenced by bf_srtm(), bfIrr2TCM(), bfRadiowater(), and simDispersion().

◆ simC2l()

int simC2l	(	double *	t,
		double *	ca,
		int	nr,
		double	k1,
		double	k2,
		double	k3,
		double	kLoss,
		double *	ct,
		double *	cta,
		double *	ctb )

Simulates tissue TAC using 2 tissue compartment model (in series) and plasma TAC, at plasma TAC times. In contrary to the common model, kLoss represents a direct loss rate from the 2nd tissue compartment to venous plasma.

Memory for ct must be allocated in the calling program. To retrieve the separate tissue compartment TACs, pointer to allocated memory for cta and ctb can be given; if compartmental TACs are not required, NULL pointer can be given instead.

The units of rate constants must be related to the time unit; 1/min and min, or 1/sec and sec.

Returns: Function returns 0 when successful, else a value >= 1.

See also: simC3s, simC3p, simC3vs, simC3vp, simC2vl, simC3vpKLoss, simRTCM, simSRTM, simTRTM, simHuangmet, simTPCMOD0009c, simMBF, simC1, simC3DIvs, simC4DIvp, simC4DIvs, simDispersion, simOxygen

Parameters

t	Array of time values
ca	Array of arterial activities
nr	Number of values in TACs
k1	Rate constant of the model
k2	Rate constant of the model
k3	Rate constant of the model
kLoss	Rate constant of the model
ct	Pointer for TAC array to be simulated; must be allocated
cta	Pointer for 1st compartment TAC to be simulated, or NULL
ctb	Pointer for 2nd compartment TAC to be simulated, or NULL

Definition at line 500 of file simulate.c.

  {
  int i;
  double b, c, dt2;
  double cai, ca_last, t_last;
  double ct1, ct1_last, ct2, ct2_last;
  double ct1i, ct1i_last, ct2i, ct2i_last;
 
 
  /* Check for data */
  if(nr<2) return 1;
  if(ct==NULL) return 2;
 
  /* Check actual parameter number */
  if(k1<0.0) return 3;
 
  /* Calculate curves */
  t_last=0.0; if(t[0]<t_last) t_last=t[0];
  cai=ca_last=0.0;
  ct1_last=ct2_last=ct1i_last=ct2i_last=ct1=ct2=ct1i=ct2i=0.0;
  for(i=0; i<nr; i++) {
    /* delta time / 2 */
    dt2=0.5*(t[i]-t_last);
    /* calculate values */
    if(dt2<0.0) {
      return 5;
    } else if(dt2>0.0) {
      /* arterial integral */
      cai+=(ca[i]+ca_last)*dt2;
      /* partial results */
      b=ct1i_last+dt2*ct1_last;
      c=ct2i_last+dt2*ct2_last;
      /* 1st tissue compartment and its integral */
      ct1 = (k1*cai - (k2+k3)*b) / (1.0 + (k2+k3)*dt2 );
      ct1i = ct1i_last + dt2*(ct1_last+ct1);
      /* 2nd tissue compartment and its integral */
      ct2 = (k3*ct1i - kLoss*c) / (1.0 + kLoss*dt2);
      ct2i = ct2i_last + dt2*(ct2_last+ct2);
    }
    /* copy values to argument arrays; set very small values to zero */
    ct[i]=ct1+ct2; if(fabs(ct[i])<1.0e-12) ct[i]=0.0;
    if(cta!=NULL) {cta[i]=ct1; if(fabs(cta[i])<1.0e-12) cta[i]=0.0;}
    if(ctb!=NULL) {ctb[i]=ct2; if(fabs(ctb[i])<1.0e-12) ctb[i]=0.0;}
    /* prepare to the next loop */
    t_last=t[i]; ca_last=ca[i];
    ct1_last=ct1; ct1i_last=ct1i;
    ct2_last=ct2; ct2i_last=ct2i;
  }
 
  return 0;
}

◆ simC2vl()

int simC2vl	(	double *	t,
		double *	ca,
		double *	cb,
		int	nr,
		double	k1,
		double	k2,
		double	k3,
		double	kL,
		double	f,
		double	vb,
		double	fa,
		double *	cpet,
		double *	cta,
		double *	ctb,
		double *	ctab,
		double *	ctvb )

Simulates tissue TAC using 2 tissue compartment model and plasma TAC, at plasma TAC times, considering also arterial and venous vasculature. The efflux from 2nd tissue compartment (at rate kL) goes directly to blood.

Memory for cpet must be allocated in the calling program. To retrieve the separate tissue compartment TACs, pointer to allocated memory for cta, ctb, ctab and/or ctvb can be given; if compartmental TACs are not required, NULL pointer can be given instead.

The units of rate constants must be related to the time unit; 1/min and min, or 1/sec and sec.

If blood flow is set to 0, function assumes that f>>k1, and Cvb=Cab.,

Returns: Function returns 0 when successful, else a value >= 1.

See also: simC3s, simC3p, simC3vs, simC3vp, simC2l, simC3vpKLoss, simRTCM, simSRTM, simTRTM, simHuangmet, simTPCMOD0009c, simMBF, simC1, simC3DIvs, simC4DIvp, simC4DIvs, simDispersion, simOxygen

Parameters

t	Array of time values
ca	Array of arterial plasma activities
cb	Array of arterial blood activities
nr	Number of values in TACs
k1	Rate constant of the model
k2	Rate constant of the model
k3	Rate constant of the model
kL	Rate constant of the model
f	Blood flow; if 0, function assumes that f>>k1, and Cvb=Cab.
vb	Vascular volume fraction
fa	Arterial fraction of vascular volume
cpet	Pointer for TAC array to be simulated; must be allocated
cta	Pointer for 1st compartment TAC to be simulated, or NULL
ctb	Pointer for 2nd compartment TAC to be simulated, or NULL
ctab	Pointer for arterial TAC in tissue, or NULL
ctvb	Pointer for venous TAC in tissue, or NULL

Definition at line 592 of file simulate.c.

  {
  int i;
  double dt2, b, c, va, vv;
  double cai, ca_last, t_last, dct, cvb;
  double ct1, ct1_last, ct2, ct2_last;
  double ct1i, ct1i_last, ct2i, ct2i_last;
 
 
  /* Check for data */
  if(nr<2) return 1;
  if(cpet==NULL) return 2;
 
  /* Check parameters */
  if(k1<0.0) return 3;
  if(vb<0.0 || vb>=1.0) return 4;
  if(fa<=0.0 || fa>1.0) return 5;
  va=fa*vb; vv=(1.0-fa)*vb;
 
  /* Calculate curves */
  t_last=0.0; if(t[0]<t_last) t_last=t[0];
  cai=ca_last=0.0;
  ct1_last=ct2_last=ct1i_last=ct2i_last=ct1=ct2=ct1i=ct2i=0.0;
  for(i=0; i<nr; i++) {
    /* delta time / 2 */
    dt2=0.5*(t[i]-t_last);
    /* calculate values */
    if(dt2<0.0) {
      return 5;
    } else if(dt2>0.0) {
      /* arterial integral */
      cai+=(ca[i]+ca_last)*dt2;
      /* Calculate partial results */
      b=ct1i_last+dt2*ct1_last;
      c=ct2i_last+dt2*ct2_last;
      /* 1st tissue compartment and its integral */
      ct1 = (k1*cai - (k2+k3)*b) / (1.0 + (k2+k3)*dt2 );
      ct1i = ct1i_last + dt2*(ct1_last+ct1);
      /* 2nd tissue compartment and its integral */
      ct2 = (k3*ct1i - kL*c) / (1.0 + kL*dt2);
      ct2i = ct2i_last + dt2*(ct2_last+ct2);
    }
    /* Venous curve */
    if(f>0.) {dct = k1*ca[i] - k2*ct1 - kL*ct2; cvb = cb[i] - dct/f;}
    else cvb=cb[i];
    /* copy values to argument arrays; set very small values to zero */
    cpet[i]= va*cb[i] + vv*cvb + (1.0-vb)*(ct1+ct2);
    if(fabs(cpet[i])<1.0e-12) cpet[i]=0.0;
    if(cta!=NULL) {cta[i]=(1.0-vb)*ct1; if(fabs(cta[i])<1.0e-12) cta[i]=0.0;}
    if(ctb!=NULL) {ctb[i]=(1.0-vb)*ct2; if(fabs(ctb[i])<1.0e-12) ctb[i]=0.0;}
    if(ctab!=NULL) {ctab[i]=va*cb[i]; if(fabs(ctab[i])<1.0e-12) ctab[i]=0.0;}
    if(ctvb!=NULL) {ctvb[i]=vv*cvb; if(fabs(ctvb[i])<1.0e-12) ctvb[i]=0.0;}
    /* prepare to the next loop */
    t_last=t[i]; ca_last=ca[i];
    ct1_last=ct1; ct1i_last=ct1i;
    ct2_last=ct2; ct2i_last=ct2i;
  }
 
  return 0;
}

◆ simC3DIvs()

int simC3DIvs	(	double *	t,
		double *	ca1,
		double *	ca2,
		double *	cb,
		int	nr,
		double	k1,
		double	k2,
		double	k3,
		double	k4,
		double	k5,
		double	k6,
		double	k1b,
		double	k2b,
		double	f,
		double	vb,
		double	fa,
		double *	scpet,
		double *	sct1,
		double *	sct2,
		double *	sct3,
		double *	sct1b,
		double *	sctab,
		double *	sctvb )

Simulates tissue TAC using dual-input tissue compartment model (1-3 compartments in series for tracer1, and 1 compartment for tracer2) at plasma TAC times, considering also contribution of arterial and venous vasculature, but no exchange between compartments for tracer1 and tracer2. The units of rate constants must be related to the time unit; 1/min and min, or 1/sec and sec. If blood flow is set to 0, function assumes that f>>k1, and Cvb=Cab.

Returns: Function returns 0 when successful, else a value >= 1.

See also: simC3s, simC3p, simC3vs, simC3vp, simC2l, simC2vl, simC3vpKLoss, simRTCM, simSRTM, simTRTM, simHuangmet, simTPCMOD0009c, simMBF, simC1, simC4DIvp, simC4DIvs, simDispersion, simOxygen

Parameters

t	Array of time values
ca1	Array of arterial plasma activities of tracer1
ca2	Array of arterial plasma activities of tracer2
cb	Array of arterial blood activities
nr	Number of values in TACs
k1	Rate constant of the model for tracer1 (from plasma to C1)
k2	Rate constant of the model for tracer1 (from C1 to plasma)
k3	Rate constant of the model for tracer1 (from C1 to C2)
k4	Rate constant of the model for tracer1 (from C2 to C1)
k5	Rate constant of the model for tracer1 (from C2 to C3)
k6	Rate constant of the model for tracer1 (from C3 to C2)
k1b	Rate constant of the model for tracer2 (from plasma to C4)
k2b	Rate constant of the model for tracer2 (from C4 to plasma)
f	Blood flow; if 0, function assumes that f>>k1, and Cvb=Cab.
vb	Vascular volume fraction
fa	Arterial fraction of vascular volume
scpet	Pointer for TAC array to be simulated; must be allocated
sct1	Pointer for 1st tracer1 compartment TAC, or NULL if not needed
sct2	Pointer for 2nd tracer1 compartment TAC, or NULL if not needed
sct3	Pointer for 3rd tracer1 compartment TAC, or NULL if not needed
sct1b	Pointer for 1st tracer2 compartment TAC, or NULL if not needed
sctab	Pointer for arterial TAC in tissue, or NULL if not needed
sctvb	Pointer for venous TAC in tissue, or NULL if not needed

Definition at line 1387 of file simulate.c.

  {
  int i;
  double b, c, d, e, w, z, dt2, va, vv;
  double ca1i, ca1_last, ca2i, ca2_last, t_last, dct, cvb;
  double ct1, ct1_last, ct2, ct2_last, ct3, ct3_last;
  double ct1i, ct1i_last, ct2i, ct2i_last, ct3i, ct3i_last;
  double ct1b, ct1b_last, ct1bi, ct1bi_last;
 
 
  /* Check for data */
  if(nr<2) return 1;
  if(scpet==NULL) return 2;
 
  /* Check parameters */
  if(k1<0.0) return 3;
  if(vb<0.0 || vb>=1.0) return 4;
  if(fa<=0.0 || fa>1.0) return 5;
  va=fa*vb; vv=(1.0-fa)*vb;
 
  /* Calculate curves */
  t_last=0.0; if(t[0]<t_last) t_last=t[0];
  ca1i=ca1_last=ca2i=ca2_last=0.0;
  ct1_last=ct2_last=ct3_last=ct1i_last=ct2i_last=ct3i_last=0.0;
  ct1b_last=ct1bi_last=0.0;
  ct1=ct2=ct3=ct1b=ct1i=ct2i=ct3i=ct1bi=0.0;
  for(i=0; i<nr; i++) {
    /* delta time / 2 */
    dt2=0.5*(t[i]-t_last);
    /* calculate values */
    if(dt2<0.0) {
      return 5;
    } else if(dt2>0.0) {
      /* arterial integrals */
      ca1i+=(ca1[i]+ca1_last)*dt2;
      ca2i+=(ca2[i]+ca2_last)*dt2;
      /* partial results */
      b=ct1i_last+dt2*ct1_last;
      c=ct2i_last+dt2*ct2_last;
      d=ct3i_last+dt2*ct3_last;
      e=ct1bi_last+dt2*ct1b_last;
      w=k4 + k5 - (k5*k6*dt2)/(1.0+k6*dt2);
      z=1.0+w*dt2;
      /* 1st tissue compartment and its integral */
      ct1 = (
          + k1*z*ca1i + (k3*k4*dt2 - (k2+k3)*z)*b
          + k4*c + k4*k6*dt2*d/(1.0+k6*dt2)
        ) / ( z*(1.0 + dt2*(k2+k3)) - k3*k4*dt2*dt2 );
      ct1i = ct1i_last + dt2*(ct1_last+ct1);
      ct1b = (k1b*ca2i - k2b*e) / (1.0 + dt2*k2b);
      ct1bi = ct1bi_last + dt2*(ct1b_last+ct1b);
      /* 2nd tissue compartment and its integral */
      ct2 = (k3*ct1i - w*c + k6*d/(1.0+k6*dt2)) / z;
      ct2i = ct2i_last + dt2*(ct2_last+ct2);
      /* 3rd tissue compartment and its integral */
      ct3 = (k5*ct2i - k6*d) / (1.0 + k6*dt2);
      ct3i = ct3i_last + dt2*(ct3_last+ct3);
    }
    /* Venous curve */
    if(f>0.) {
      dct = k1*ca1[i] - k2*ct1 + k1b*ca2[i] - k2b*ct1b;
      cvb = cb[i] - dct/f;
    } else cvb=cb[i];
    /* copy values to argument arrays; set very small values to zero */
    scpet[i]= va*cb[i] + vv*cvb + (1.0-vb)*(ct1+ct2+ct3+ct1b);
    if(fabs(scpet[i])<1.0e-12) scpet[i]=0.0;
    if(sct1!=NULL) {sct1[i]=(1.0-vb)*ct1; if(fabs(sct1[i])<1.0e-12) sct1[i]=0.0;}
    if(sct2!=NULL) {sct2[i]=(1.0-vb)*ct2; if(fabs(sct2[i])<1.0e-12) sct2[i]=0.0;}
    if(sct3!=NULL) {sct3[i]=(1.0-vb)*ct3; if(fabs(sct3[i])<1.0e-12) sct3[i]=0.0;}
    if(sct1b!=NULL) {
      sct1b[i]=(1.0-vb)*ct1b; if(fabs(sct1b[i])<1.0e-12) sct1b[i]=0.0;}
    if(sctab!=NULL) {sctab[i]=va*cb[i]; if(fabs(sctab[i])<1.0e-12) sctab[i]=0.0;}
    if(sctvb!=NULL) {sctvb[i]=vv*cvb; if(fabs(sctvb[i])<1.0e-12) sctvb[i]=0.0;}
    /* prepare to the next loop */
    t_last=t[i]; ca1_last=ca1[i]; ca2_last=ca2[i];
    ct1_last=ct1; ct1i_last=ct1i;
    ct2_last=ct2; ct2i_last=ct2i;
    ct3_last=ct3; ct3i_last=ct3i;
    ct1b_last=ct1b; ct1bi_last=ct1bi;
  }
 
  return 0;
}

◆ simC3p()

int simC3p	(	double *	t,
		double *	ca,
		int	nr,
		double	k1,
		double	k2,
		double	k3,
		double	k4,
		double	k5,
		double	k6,
		double *	ct,
		double *	cta,
		double *	ctb,
		double *	ctc )

Simulates tissue TAC using 1-3 tissue compartment model (2nd and 3rd compartments in parallel) and plasma TAC, at plasma TAC times.

Memory for ct must be allocated in the calling program. To retrieve the separate tissue compartment TACs, pointer to allocated memory for cta, ctb and/or ctc can be given; if compartmental TACs are not required, NULL pointer can be given instead.

The units of rate constants must be related to the time unit; 1/min and min, or 1/sec and sec.

Returns: Function returns 0 when successful, else a value >= 1.

See also: simC3s, simC3vs, simC3vp, simC2l, simC2vl, simC3vpKLoss, simRTCM, simSRTM, simTRTM, simHuangmet, simTPCMOD0009c, simMBF, simC1, simC3DIvs, simC4DIvp, simC4DIvs, simDispersion, simOxygen

Parameters

t	Array of time values
ca	Array of arterial activities
nr	Number of values in TACs
k1	Rate constant of the model
k2	Rate constant of the model
k3	Rate constant of the model
k4	Rate constant of the model
k5	Rate constant of the model
k6	Rate constant of the model
ct	Pointer for TAC array to be simulated; must be allocated
cta	Pointer for 1st compartment TAC to be simulated, or NULL
ctb	Pointer for 2nd compartment TAC to be simulated, or NULL
ctc	Pointer for 3rd compartment TAC to be simulated, or NULL

Definition at line 136 of file simulate.c.

  {
  int i;
  double dt2, r, s, u, v, w;
  double cai, ca_last, t_last;
  double ct1, ct1_last, ct2, ct2_last, ct3, ct3_last;
  double ct1i, ct1i_last, ct2i, ct2i_last, ct3i, ct3i_last;
 
 
  /* Check for data */
  if(nr<2) return 1;
  if(ct==NULL) return 2;
 
  /* Check parameters */
  if(k1<0.0) return 3;
 
  /* Calculate curves */
  t_last=0.0; if(t[0]<t_last) t_last=t[0];
  cai=ca_last=0.0;
  ct1_last=ct2_last=ct3_last=ct1i_last=ct2i_last=ct3i_last=0.0;
  ct1=ct2=ct3=ct1i=ct2i=ct3i=0.0;
  for(i=0; i<nr; i++) {
    /* delta time / 2 */
    dt2=0.5*(t[i]-t_last);
    /* calculate values */
    if(dt2<0.0) {
      return 5;
    } else if(dt2>0.0) {
      /* arterial integral */
      cai+=(ca[i]+ca_last)*dt2;
      /* Calculate partial results */
      r=1.0+k4*dt2;
      s=1.0+k6*dt2;
      u=ct1i_last+dt2*ct1_last;
      v=ct2i_last+dt2*ct2_last;
      w=ct3i_last+dt2*ct3_last;
      /* 1st tissue compartment and its integral */
      ct1 = ( k1*cai - (k2 + (k3/r) + (k5/s))*u + (k4/r)*v + (k6/s)*w )
            / ( 1.0 + dt2*(k2 + (k3/r) + (k5/s)) );
      ct1i = ct1i_last + dt2*(ct1_last+ct1);
      /* 2nd tissue compartment and its integral */
      ct2 = (k3*ct1i - k4*v) / r;
      ct2i = ct2i_last + dt2*(ct2_last+ct2);
      /* 3rd tissue compartment and its integral */
      ct3 = (k5*ct1i - k6*w) / s;
      ct3i = ct3i_last + dt2*(ct3_last+ct3);
    }
    /* copy values to argument arrays; set very small values to zero */
    ct[i]=ct1+ct2+ct3; if(fabs(ct[i])<1.0e-12) ct[i]=0.0;
    if(cta!=NULL) {cta[i]=ct1; if(fabs(cta[i])<1.0e-12) cta[i]=0.0;}
    if(ctb!=NULL) {ctb[i]=ct2; if(fabs(ctb[i])<1.0e-12) ctb[i]=0.0;}
    if(ctc!=NULL) {ctc[i]=ct3; if(fabs(ctc[i])<1.0e-12) ctc[i]=0.0;}
    /* prepare to the next loop */
    t_last=t[i]; ca_last=ca[i];
    ct1_last=ct1; ct1i_last=ct1i;
    ct2_last=ct2; ct2i_last=ct2i;
    ct3_last=ct3; ct3i_last=ct3i;
  }
 
  return 0;
}

◆ simC3s()

int simC3s	(	double *	t,
		double *	ca,
		int	nr,
		double	k1,
		double	k2,
		double	k3,
		double	k4,
		double	k5,
		double	k6,
		double *	ct,
		double *	cta,
		double *	ctb,
		double *	ctc )

Simulates tissue TAC using 1-3 tissue compartment model (in series) and plasma TAC, at plasma TAC times.

Memory for ct must be allocated in the calling program. To retrieve the separate tissue compartment TACs, pointer to allocated memory for cta, ctb and/or ctc can be given; if compartmental TACs are not required, NULL pointer can be given instead.

The units of rate constants must be related to the time unit; 1/min and min, or 1/sec and sec.

Returns: Function returns 0 when successful, else a value >= 1.

See also: simC3p, simC3vs, simC3vp, simC2l, simC2vl, simC3vpKLoss, simRTCM, simSRTM, simTRTM, simHuangmet, simTPCMOD0009c, simMBF, simC1, simC3DIvs, simC4DIvp, simC4DIvs, simDispersion, simOxygen

Parameters

t	Array of time values
ca	Array of arterial activities
nr	Number of values in TACs
k1	Rate constant of the model
k2	Rate constant of the model
k3	Rate constant of the model
k4	Rate constant of the model
k5	Rate constant of the model
k6	Rate constant of the model
ct	Pointer for TAC array to be simulated; must be allocated
cta	Pointer for 1st compartment TAC to be simulated, or NULL
ctb	Pointer for 2nd compartment TAC to be simulated, or NULL
ctc	Pointer for 3rd compartment TAC to be simulated, or NULL

Definition at line 27 of file simulate.c.

  {
  double b, c, d, w, z, dt2;
  double cai, ca_last, t_last;
  double ct1, ct1_last, ct2, ct2_last, ct3, ct3_last;
  double ct1i, ct1i_last, ct2i, ct2i_last, ct3i, ct3i_last;
 
 
  /* Check for data */
  if(nr<2) return 1;
  if(ct==NULL) return 2;
 
  /* Check actual parameter number */
  if(k1<0.0) return 3;
  if(k3<=0.0) {k3=0.0; if(k2<=0.0) {k2=0.0;}}
  else if(k5<=0.0) {k5=0.0; if(k4<=0.0) {k4=0.0;}}
  else if(k6<=0.0) {k6=0.0;}
 
  /* Calculate curves */
  t_last=0.0; if(t[0]<t_last) t_last=t[0]; 
  cai=ca_last=0.0;
  ct1_last=ct2_last=ct3_last=ct1i_last=ct2i_last=ct3i_last=0.0;
  ct1=ct2=ct3=ct1i=ct2i=ct3i=0.0;
  for(int i=0; i<nr; i++) {
    /* delta time / 2 */
    dt2=0.5*(t[i]-t_last);
    /* calculate values */
    if(dt2<0.0) {
      return 5;
    } else if(dt2>0.0) {
      /* arterial integral */
      cai+=(ca[i]+ca_last)*dt2;
      /* partial results */
      b=ct1i_last+dt2*ct1_last;
      c=ct2i_last+dt2*ct2_last;
      d=ct3i_last+dt2*ct3_last;
      w=k4 + k5 - (k5*k6*dt2)/(1.0+k6*dt2);
      z=1.0+w*dt2;
      /* 1st tissue compartment and its integral */
      ct1 = (
          + k1*z*cai + (k3*k4*dt2 - (k2+k3)*z)*b
          + k4*c + k4*k6*dt2*d/(1.0+k6*dt2)
        ) / ( z*(1.0 + dt2*(k2+k3)) - k3*k4*dt2*dt2 );
      ct1i = ct1i_last + dt2*(ct1_last+ct1);
      /* 2nd tissue compartment and its integral */
      ct2 = (k3*ct1i - w*c + k6*d/(1.0+k6*dt2)) / z;
      ct2i = ct2i_last + dt2*(ct2_last+ct2);
      /* 3rd tissue compartment and its integral */
      ct3 = (k5*ct2i - k6*d) / (1.0 + k6*dt2);
      ct3i = ct3i_last + dt2*(ct3_last+ct3);
    }
    /* copy values to argument arrays; set very small values to zero */
    ct[i]=ct1+ct2+ct3; if(fabs(ct[i])<1.0e-12) ct[i]=0.0;
    if(cta!=NULL) {cta[i]=ct1; if(fabs(cta[i])<1.0e-12) cta[i]=0.0;}
    if(ctb!=NULL) {ctb[i]=ct2; if(fabs(ctb[i])<1.0e-12) ctb[i]=0.0;}
    if(ctc!=NULL) {ctc[i]=ct3; if(fabs(ctc[i])<1.0e-12) ctc[i]=0.0;}
    /* prepare to the next loop */
    t_last=t[i]; ca_last=ca[i];
    ct1_last=ct1; ct1i_last=ct1i;
    ct2_last=ct2; ct2i_last=ct2i;
    ct3_last=ct3; ct3i_last=ct3i;
  }
 
  return 0;
}

◆ simC3vp()

int simC3vp	(	double *	t,
		double *	ca,
		double *	cb,
		int	nr,
		double	k1,
		double	k2,
		double	k3,
		double	k4,
		double	k5,
		double	k6,
		double	f,
		double	vb,
		double	fa,
		double *	cpet,
		double *	cta,
		double *	ctb,
		double *	ctc,
		double *	ctab,
		double *	ctvb )

Simulates tissue TAC using 1-3 tissue compartment model (2nd and 3rd compartments in parallel) and plasma TAC, at plasma TAC times, considering also arterial and venous vasculature.

Memory for cpet must be allocated in the calling program. To retrieve the separate tissue compartment TACs, pointer to allocated memory for cta, ctb, ctc, ctab and/or ctvb can be given; if compartmental TACs are not required, NULL pointer can be given instead.

The units of rate constants must be related to the time unit; 1/min and min, or 1/sec and sec.

If blood flow is set to 0, function assumes that f>>k1, and Cvb=Cab.,

Returns: Function returns 0 when successful, else a value >= 1.

See also: simC3s, simC3p, simC3vs, simC2l, simC2vl, simC3vpKLoss, simRTCM, simSRTM, simTRTM, simHuangmet, simTPCMOD0009c, simMBF, simC1, simC3DIvs, simC4DIvp, simC4DIvs, simDispersion, simOxygen

Parameters

t	Array of time values
ca	Array of arterial plasma activities
cb	Array of arterial blood activities
nr	Number of values in TACs
k1	Rate constant of the model
k2	Rate constant of the model
k3	Rate constant of the model
k4	Rate constant of the model
k5	Rate constant of the model
k6	Rate constant of the model
f	Blood flow; if 0, function assumes that f>>k1, and Cvb=Cab.
vb	Vascular volume fraction
fa	Arterial fraction of vascular volume
cpet	Pointer for TAC array to be simulated; must be allocated
cta	Pointer for 1st compartment TAC to be simulated, or NULL
ctb	Pointer for 2nd compartment TAC to be simulated, or NULL
ctc	Pointer for 3rd compartment TAC to be simulated, or NULL
ctab	Pointer for arterial TAC in tissue, or NULL
ctvb	Pointer for venous TAC in tissue, or NULL

Definition at line 373 of file simulate.c.

  {
  int i;
  double dt2, r, s, u, v, w, va, vv;
  double cai, ca_last, t_last, dct, cvb;
  double ct1, ct1_last, ct2, ct2_last, ct3, ct3_last;
  double ct1i, ct1i_last, ct2i, ct2i_last, ct3i, ct3i_last;
 
 
  /* Check for data */
  if(nr<2) return 1;
  if(cpet==NULL) return 2;
 
  /* Check parameters */
  if(k1<0.0) return 3;
  if(vb<0.0 || vb>=1.0) return 4;
  if(fa<=0.0 || fa>1.0) return 5;
  va=fa*vb; vv=(1.0-fa)*vb;
 
  /* Calculate curves */
  t_last=0.0; if(t[0]<t_last) t_last=t[0];
  cai=ca_last=0.0;
  ct1_last=ct2_last=ct3_last=ct1i_last=ct2i_last=ct3i_last=0.0;
  ct1=ct2=ct3=ct1i=ct2i=ct3i=0.0;
  for(i=0; i<nr; i++) {
    /* delta time / 2 */
    dt2=0.5*(t[i]-t_last);
    /* calculate values */
    if(dt2<0.0) {
      return 5;
    } else if(dt2>0.0) {
      /* arterial integral */
      cai+=(ca[i]+ca_last)*dt2;
      /* Calculate partial results */
      r=1.0+k4*dt2;
      s=1.0+k6*dt2;
      u=ct1i_last+dt2*ct1_last;
      v=ct2i_last+dt2*ct2_last;
      w=ct3i_last+dt2*ct3_last;
      /* 1st tissue compartment and its integral */
      ct1 = ( k1*cai - (k2 + (k3/r) + (k5/s))*u + (k4/r)*v + (k6/s)*w )
            / ( 1.0 + dt2*(k2 + (k3/r) + (k5/s)) );
      ct1i = ct1i_last + dt2*(ct1_last+ct1);
      /* 2nd tissue compartment and its integral */
      ct2 = (k3*ct1i - k4*v) / r;
      ct2i = ct2i_last + dt2*(ct2_last+ct2);
      /* 3rd tissue compartment and its integral */
      ct3 = (k5*ct1i - k6*w) / s;
      ct3i = ct3i_last + dt2*(ct3_last+ct3);
    }
    /* Venous curve */
    if(f>0.) {dct = k1*ca[i] - k2*ct1; cvb = cb[i] - dct/f;} else cvb=cb[i];
    /* copy values to argument arrays; set very small values to zero */
    cpet[i]= va*cb[i] + vv*cvb + (1.0-vb)*(ct1+ct2+ct3);
    if(fabs(cpet[i])<1.0e-12) cpet[i]=0.0;
    if(cta!=NULL) {cta[i]=(1.0-vb)*ct1; if(fabs(cta[i])<1.0e-12) cta[i]=0.0;}
    if(ctb!=NULL) {ctb[i]=(1.0-vb)*ct2; if(fabs(ctb[i])<1.0e-12) ctb[i]=0.0;}
    if(ctc!=NULL) {ctc[i]=(1.0-vb)*ct3; if(fabs(ctc[i])<1.0e-12) ctc[i]=0.0;}
    if(ctab!=NULL) {ctab[i]=va*cb[i]; if(fabs(ctab[i])<1.0e-12) ctab[i]=0.0;}
    if(ctvb!=NULL) {ctvb[i]=vv*cvb; if(fabs(ctvb[i])<1.0e-12) ctvb[i]=0.0;}
    /* prepare to the next loop */
    t_last=t[i]; ca_last=ca[i];
    ct1_last=ct1; ct1i_last=ct1i;
    ct2_last=ct2; ct2i_last=ct2i;
    ct3_last=ct3; ct3i_last=ct3i;
  }
 
  return 0;
}

◆ simC3vpKLoss()

int simC3vpKLoss	(	double *	t,
		double *	ca,
		double *	cb,
		int	nr,
		double	k1,
		double	k2,
		double	k3,
		double	k4,
		double	k5,
		double	k6,
		double	kLoss,
		double	f,
		double	vb,
		double	fa,
		double *	cpet,
		double *	cta,
		double *	ctb,
		double *	ctc,
		double *	ctab,
		double *	ctvb )

Simulates tissue TAC using 3 tissue compartmental model with two parallel compartments, and plasma TAC, at plasma TAC sample times, considering also arterial and venous vasculature. The efflux from 3rd tissue compartment (C) goes directly to blood at rate kLoss.

Memory for cpet must be allocated in the calling program. To retrieve the separate tissue compartment TACs, pointer to allocated memory for cta, ctb, ctab and/or ctvb can be given; if compartmental TACs are not required, NULL pointer can be given instead.

The units of rate constants must be related to the time unit; 1/min and min, or 1/sec and sec.

If blood flow is set to 0, function assumes that f>>k1, and Cvb=Cab.,

Returns: Function returns 0 when successful, else a value >= 1.

See also: simC3s, simC3p, simC3vs, simC3vp, simC2l, simC2vl, simRTCM, simSRTM, simTRTM, simHuangmet, simTPCMOD0009c, simMBF, simC1, simC3DIvs, simC4DIvp, simC4DIvs, simDispersion, simOxygen

Parameters

t	Array of sample times
ca	Array of arterial plasma activities
cb	Array of arterial blood activities
nr	Number of sample values in TACs
k1	Rate constant of the model
k2	Rate constant of the model
k3	Rate constant of the model
k4	Rate constant of the model
k5	Rate constant of the model
k6	Rate constant of the model
kLoss	Rate constant of the model
f	Blood flow; if 0, function assumes that f>>k1, and Cvb=Cab.
vb	Vascular volume fraction
fa	Arterial fraction of vascular volume
cpet	Pointer for TAC array to be simulated; must be allocated
cta	Pointer for 1st tissue compartment TAC to be simulated, or NULL
ctb	Pointer for 2nd compartment TAC to be simulated, or NULL
ctc	Pointer for 3rd compartment TAC to be simulated, or NULL
ctab	Pointer for arterial TAC in tissue, or NULL
ctvb	Pointer for venous TAC in tissue, or NULL

Definition at line 707 of file simulate.c.

  {
  int i;
  double dt2, b, c, d, w, z, u, va, vv;
  double cai, ca_last, t_last, dct, cvb;
  double ct1, ct1_last, ct2, ct2_last, ct3, ct3_last;
  double ct1i, ct1i_last, ct2i, ct2i_last, ct3i, ct3i_last;
 
 
  /* Check for data */
  if(nr<2) return 1;
  if(cpet==NULL) return 2;
 
  /* Check parameters */
  if(k1<0.0) return 3;
  if(vb<0.0 || vb>=1.0) return 4;
  if(fa<=0.0 || fa>1.0) return 5;
  va=fa*vb; vv=(1.0-fa)*vb;
 
  /* Calculate curves */
  t_last=0.0; if(t[0]<t_last) t_last=t[0];
  cai=ca_last=0.0;
  ct1_last=ct2_last=ct3_last=ct1i_last=ct2i_last=ct3i_last=0.0;
  ct1=ct2=ct3=ct1i=ct2i=ct3i=0.0;
  for(i=0; i<nr; i++) {
    /* delta time / 2 */
    dt2=0.5*(t[i]-t_last);
    /* calculate values */
    if(dt2<0.0) {
      return 5;
    } else if(dt2>0.0) {
      /* arterial integral */
      cai+=(ca[i]+ca_last)*dt2;
      /* Calculate partial results */
      w = 1.0 + k4*dt2;
      z = 1.0 + dt2*(k6 + kLoss); 
      u = k2 + k3 + k5 - k3*k4*dt2/w - k5*k6*dt2/z;
      b = ct1i_last+dt2*ct1_last;
      c = ct2i_last+dt2*ct2_last;
      d = ct3i_last+dt2*ct3_last;
      /* 1st tissue compartment and its integral */
      ct1 = ( k1*cai - u*b + k4*c/w + k6*d/z ) / ( 1.0 + dt2*u);
      ct1i = ct1i_last + dt2*(ct1_last+ct1);
      /* 2nd tissue compartment and its integral */
      ct2 = (k3*ct1i - k4*c) / w;
      ct2i = ct2i_last + dt2*(ct2_last+ct2);
      /* 3rd tissue compartment and its integral */
      ct3 = (k5*ct1i - (k6 + kLoss)*d) / z;
      ct3i = ct3i_last + dt2*(ct3_last+ct3);
    }
    /* Venous curve */
    if(f>0.) {dct = k1*ca[i] - k2*ct1 - kLoss*ct3; cvb = cb[i] - dct/f;}
    else cvb=cb[i];
    /* copy values to argument arrays; set very small values to zero */
    cpet[i]= va*cb[i] + vv*cvb + (1.0-vb)*(ct1+ct2+ct3);
    if(fabs(cpet[i])<1.0e-12) cpet[i]=0.0;
    if(cta!=NULL) {cta[i]=(1.0-vb)*ct1; if(fabs(cta[i])<1.0e-12) cta[i]=0.0;}
    if(ctb!=NULL) {ctb[i]=(1.0-vb)*ct2; if(fabs(ctb[i])<1.0e-12) ctb[i]=0.0;}
    if(ctc!=NULL) {ctc[i]=(1.0-vb)*ct3; if(fabs(ctc[i])<1.0e-12) ctc[i]=0.0;}
    if(ctab!=NULL) {ctab[i]=va*cb[i]; if(fabs(ctab[i])<1.0e-12) ctab[i]=0.0;}
    if(ctvb!=NULL) {ctvb[i]=vv*cvb; if(fabs(ctvb[i])<1.0e-12) ctvb[i]=0.0;}
    /* prepare to the next loop */
    t_last=t[i]; ca_last=ca[i];
    ct1_last=ct1; ct1i_last=ct1i;
    ct2_last=ct2; ct2i_last=ct2i;
    ct3_last=ct3; ct3i_last=ct3i;
  }
  
  return 0;
}

◆ simC3vs()

int simC3vs	(	double *	t,
		double *	ca,
		double *	cb,
		int	nr,
		double	k1,
		double	k2,
		double	k3,
		double	k4,
		double	k5,
		double	k6,
		double	f,
		double	vb,
		double	fa,
		double *	cpet,
		double *	cta,
		double *	ctb,
		double *	ctc,
		double *	ctab,
		double *	ctvb )

Simulates tissue TAC using 1-3 tissue compartment model (in series) and plasma TAC, at plasma TAC times, considering also arterial and venous vasculature.

Memory for cpet must be allocated in the calling program. To retrieve the separate tissue compartment TACs, pointer to allocated memory for cta, ctb, ctc, ctab and/or ctvb can be given; if compartmental TACs are not required, NULL pointer can be given instead.

The units of rate constants must be related to the time unit; 1/min and min, or 1/sec and sec.

If blood flow is set to 0, function assumes that f>>k1, and Cvb=Cab.,

Returns: Function returns 0 when successful, else a value >= 1.

See also: simC3s, simC3p, simC3vp, simC2l, simC2vl, simC3vpKLoss, simRTCM, simSRTM, simTRTM, simHuangmet, simTPCMOD0009c, simMBF, simC1, simC3DIvs, simC4DIvp, simC4DIvs, simDispersion, simOxygen

Parameters

t	Array of time values
ca	Array of arterial plasma activities
cb	Array of arterial blood activities
nr	Number of values in TACs
k1	Rate constant of the model
k2	Rate constant of the model
k3	Rate constant of the model
k4	Rate constant of the model
k5	Rate constant of the model
k6	Rate constant of the model
f	Blood flow; if 0, function assumes that f>>k1, and Cvb=Cab.
vb	Vascular volume fraction
fa	Arterial fraction of vascular volume
cpet	Pointer for TAC array to be simulated; must be allocated
cta	Pointer for 1st compartment TAC to be simulated, or NULL
ctb	Pointer for 2nd compartment TAC to be simulated, or NULL
ctc	Pointer for 3rd compartment TAC to be simulated, or NULL
ctab	Pointer for arterial TAC in tissue, or NULL
ctvb	Pointer for venous TAC in tissue, or NULL

Definition at line 243 of file simulate.c.

  {
  int i;
  double b, c, d, w, z, dt2, va, vv;
  double cai, ca_last, t_last, dct, cvb;
  double ct1, ct1_last, ct2, ct2_last, ct3, ct3_last;
  double ct1i, ct1i_last, ct2i, ct2i_last, ct3i, ct3i_last;
 
 
  /* Check for data */
  if(nr<2) return 1;
  if(cpet==NULL) return 2;
 
  /* Check parameters */
  if(k1<0.0) return 3;
  if(vb<0.0 || vb>=1.0) return 4;
  if(fa<=0.0 || fa>1.0) return 5;
  va=fa*vb; vv=(1.0-fa)*vb;
 
  /* Calculate curves */
  t_last=0.0; if(t[0]<t_last) t_last=t[0];
  cai=ca_last=0.0;
  ct1_last=ct2_last=ct3_last=ct1i_last=ct2i_last=ct3i_last=0.0;
  ct1=ct2=ct3=ct1i=ct2i=ct3i=0.0;
  for(i=0; i<nr; i++) {
    /* delta time / 2 */
    dt2=0.5*(t[i]-t_last);
    /* calculate values */
    if(dt2<0.0) {
      return 5;
    } else if(dt2>0.0) {
      /* arterial integral */
      cai+=(ca[i]+ca_last)*dt2;
      /* partial results */
      b=ct1i_last+dt2*ct1_last;
      c=ct2i_last+dt2*ct2_last;
      d=ct3i_last+dt2*ct3_last;
      w=k4 + k5 - (k5*k6*dt2)/(1.0+k6*dt2);
      z=1.0+w*dt2;
      /* 1st tissue compartment and its integral */
      ct1 = (
          + k1*z*cai + (k3*k4*dt2 - (k2+k3)*z)*b
          + k4*c + k4*k6*dt2*d/(1.0+k6*dt2)
        ) / ( z*(1.0 + dt2*(k2+k3)) - k3*k4*dt2*dt2 );
      ct1i = ct1i_last + dt2*(ct1_last+ct1);
      /* 2nd tissue compartment and its integral */
      ct2 = (k3*ct1i - w*c + k6*d/(1.0+k6*dt2)) / z;
      ct2i = ct2i_last + dt2*(ct2_last+ct2);
      /* 3rd tissue compartment and its integral */
      ct3 = (k5*ct2i - k6*d) / (1.0 + k6*dt2);
      ct3i = ct3i_last + dt2*(ct3_last+ct3);
    }
    /* Venous curve */
    if(f>0.) {dct = k1*ca[i] - k2*ct1; cvb = cb[i] - dct/f;} else cvb=cb[i];
    /* copy values to argument arrays; set very small values to zero */
    cpet[i]= va*cb[i] + vv*cvb + (1.0-vb)*(ct1+ct2+ct3);
    if(fabs(cpet[i])<1.0e-12) cpet[i]=0.0;
    if(cta!=NULL) {cta[i]=(1.0-vb)*ct1; if(fabs(cta[i])<1.0e-12) cta[i]=0.0;}
    if(ctb!=NULL) {ctb[i]=(1.0-vb)*ct2; if(fabs(ctb[i])<1.0e-12) ctb[i]=0.0;}
    if(ctc!=NULL) {ctc[i]=(1.0-vb)*ct3; if(fabs(ctc[i])<1.0e-12) ctc[i]=0.0;}
    if(ctab!=NULL) {ctab[i]=va*cb[i]; if(fabs(ctab[i])<1.0e-12) ctab[i]=0.0;}
    if(ctvb!=NULL) {ctvb[i]=vv*cvb; if(fabs(ctvb[i])<1.0e-12) ctvb[i]=0.0;}
    /* prepare to the next loop */
    t_last=t[i]; ca_last=ca[i];
    ct1_last=ct1; ct1i_last=ct1i;
    ct2_last=ct2; ct2i_last=ct2i;
    ct3_last=ct3; ct3i_last=ct3i;
  }
 
  return 0;
}

◆ simC4DIvp()

int simC4DIvp	(	double *	t,
		double *	ca1,
		double *	ca2,
		double *	cb,
		int	nr,
		double	k1,
		double	k2,
		double	k3,
		double	k4,
		double	k5,
		double	k6,
		double	k7,
		double	km,
		double	k1b,
		double	k2b,
		double	f,
		double	vb,
		double	fa,
		double *	scpet,
		double *	sct1,
		double *	sct2,
		double *	sct3,
		double *	sct1b,
		double *	sctab,
		double *	sctvb,
		int	verbose )

Simulates tissue TAC using dual-input tissue compartment model (compartments 2 and 3 in parallel for tracer1, and 1 compartment for tracer2) at plasma TAC sample times, considering also contribution of arterial and venous vasculature, and transfer of tracer1 to tracer2. The units of rate constants must be related to the time unit; 1/min and min, or 1/sec and sec. If blood flow is set to 0, function assumes that f>>k1, and Cvb=Cab. Reference: TPCMOD0001 Appendix C. Tested with program p2t_di -parallel.

Returns: Function returns 0 when successful, else a value >= 1.

See also: simC3s, simC3p, simC3vs, simC3vp, simC2l, simC2vl, simC3vpKLoss, simRTCM, simSRTM, simTRTM, simHuangmet, simTPCMOD0009c, simMBF, simC1, simC3DIvs, simC4DIvs, simDispersion, simOxygen

Parameters

t	Array of time values
ca1	Array of arterial plasma activities of tracer1 (parent tracer)
ca2	Array of arterial plasma activities of tracer2 (metabolite)
cb	Array of (total) arterial blood activities
nr	Number of values in TACs
k1	Rate constant of the model for tracer1 (from plasma to C1)
k2	Rate constant of the model for tracer1 (from C1 to plasma)
k3	Rate constant of the model for tracer1 (from C1 to C2)
k4	Rate constant of the model for tracer1 (from C2 to C1)
k5	Rate constant of the model for tracer1 (from C1 to C3)
k6	Rate constant of the model for tracer1 (from C3 to C1)
k7	Rate constant of the model for tracer1 (from C3 to plasma)
km	Rate constant of the model (from tracer1 in C1 to tracer2 in C4)
k1b	Rate constant of the model for tracer2 (from plasma to C4)
k2b	Rate constant of the model for tracer2 (from C4 to plasma)
f	Blood flow; if 0, function assumes that f>>k1, and Cvb=Cab
vb	Vascular volume fraction (0<=Vb<1)
fa	Arterial fraction of vascular volume (0<=fa<=1)
scpet	Pointer for TAC array to be simulated; must be allocated
sct1	Pointer for 1st tracer1 compartment TAC, or NULL if not needed
sct2	Pointer for 2nd tracer1 compartment TAC, or NULL if not needed
sct3	Pointer for 3rd tracer1 compartment TAC, or NULL if not needed
sct1b	Pointer for 1st tracer2 compartment TAC, or NULL if not needed
sctab	Pointer for arterial TAC in tissue, or NULL if not needed
sctvb	Pointer for venous TAC in tissue, or NULL if not needed
verbose	Verbose level; if zero, then nothing is printed into stdout or stderr

Definition at line 1533 of file simulate.c.

  {
  int i;
  double b, c, d, e, pt, qt, dt2, va, vv;
  double ca1i, ca1_last, ca2i, ca2_last, t_last, dct, cvb;
  double ct1, ct1_last, ct2, ct2_last, ct3, ct3_last;
  double ct1i, ct1i_last, ct2i, ct2i_last, ct3i, ct3i_last;
  double ct1b, ct1b_last, ct1bi, ct1bi_last;
 
 
  if(verbose>0) {
    printf("simC4DIvp()\n");
    if(verbose>1) {
      printf("  k1 := %g\n", k1);
      printf("  k2 := %g\n", k2);
      printf("  k3 := %g\n", k3);
      printf("  k4 := %g\n", k4);
      printf("  k5 := %g\n", k5);
      printf("  k6 := %g\n", k6);
      printf("  k7 := %g\n", k7);
      printf("  km := %g\n", km);
      printf("  k1b := %g\n", k1b);
      printf("  k2b := %g\n", k2b);
      printf("  vb := %g\n", vb);
      printf("  fa := %g\n", fa);
      printf("  f := %g\n", f);
    }
  }
 
  /* Check for data */
  if(nr<2) return 1;
  if(scpet==NULL) return 2;
 
  /* Check parameters */
  if(k1<0.0 || k1b<0.0) return 3;
  if(vb<0.0 || vb>=1.0) return 4;
  if(fa<0.0 || fa>1.0) return 5;
  va=fa*vb; vv=(1.0-fa)*vb;
 
  /* Calculate curves */
  t_last=0.0; if(t[0]<t_last) t_last=t[0];
  ca1i=ca1_last=ca2i=ca2_last=0.0;
  ct1_last=ct2_last=ct3_last=ct1i_last=ct2i_last=ct3i_last=ct1b_last=
  ct1bi_last=0.0;
  ct1=ct2=ct3=ct1b=ct1i=ct2i=ct3i=ct1bi=0.0;
  for(i=0; i<nr; i++) {
    /* delta time / 2 */
    dt2=0.5*(t[i]-t_last);
    /* calculate values */
    if(dt2<0.0) {
      return 5;
    } else if(dt2>0.0) {
      /* arterial integrals */
      ca1i+=(ca1[i]+ca1_last)*dt2;
      ca2i+=(ca2[i]+ca2_last)*dt2;
      /* partial results */
      b=ct1i_last+dt2*ct1_last;
      c=ct2i_last+dt2*ct2_last;
      d=ct3i_last+dt2*ct3_last;
      e=ct1bi_last+dt2*ct1b_last;
      pt=k6+k7;
      qt=k2+k3+k5+km-(k3*k4*dt2)/(1.0+k4*dt2)-(k5*k6*dt2)/(1.0+pt*dt2);
      /* 1st tissue compartment and its integral */
      ct1 = (k1/(1.0+qt*dt2))*ca1i
    - (qt/(1.0+qt*dt2))*b
          + (k4/((1.0+qt*dt2)*(1.0+k4*dt2)))*c
          + (k6/((1.0+qt*dt2)*(1.0+pt*dt2)))*d;
      ct1i = ct1i_last + dt2*(ct1_last+ct1);
      /* 2nd tissue compartment and its integral */
      ct2 = (k3/(1.0+k4*dt2))*ct1i
          - (k4/(1.0+k4*dt2))*c;
      ct2i = ct2i_last + dt2*(ct2_last+ct2);
      /* 3rd tissue compartment and its integral */
      ct3 = (k5/(1.0+pt*dt2))*ct1i
          - (pt/(1.0+pt*dt2))*d;
      ct3i = ct3i_last + dt2*(ct3_last+ct3);
      /* 4th tissue compartment (the 1st for tracer 2) and its integral */
      ct1b = (k1b/(1.0+k2b*dt2))*ca2i
           - (k2b/(1.0+k2b*dt2))*e
           + (km/(1.0+k2b*dt2))*ct1i;
      ct1bi = ct1bi_last + dt2*(ct1b_last+ct1b);
    }
    /* Venous curve */
    if(f>0.) {
      dct = k1*ca1[i] - k2*ct1 - k7*ct3 + k1b*ca2[i] - k2b*ct1b;
      cvb = cb[i] - dct/f;
    } else cvb=cb[i];
    /* copy values to argument arrays; set very small values to zero */
    scpet[i]= va*cb[i] + vv*cvb + (1.0-vb)*(ct1+ct2+ct3+ct1b);
    if(fabs(scpet[i])<1.0e-12) scpet[i]=0.0;
    if(sct1!=NULL) {
      sct1[i]=(1.0-vb)*ct1; if(fabs(sct1[i])<1.0e-12) sct1[i]=0.0;}
    if(sct2!=NULL) {
      sct2[i]=(1.0-vb)*ct2; if(fabs(sct2[i])<1.0e-12) sct2[i]=0.0;}
    if(sct3!=NULL) {
      sct3[i]=(1.0-vb)*ct3; if(fabs(sct3[i])<1.0e-12) sct3[i]=0.0;}
    if(sct1b!=NULL) {
      sct1b[i]=(1.0-vb)*ct1b; if(fabs(sct1b[i])<1.0e-12) sct1b[i]=0.0;}
    if(sctab!=NULL) {
      sctab[i]=va*cb[i]; if(fabs(sctab[i])<1.0e-12) sctab[i]=0.0;}
    if(sctvb!=NULL) {
      sctvb[i]=vv*cvb; if(fabs(sctvb[i])<1.0e-12) sctvb[i]=0.0;}
    /* prepare to the next loop */
    t_last=t[i]; ca1_last=ca1[i]; ca2_last=ca2[i];
    ct1_last=ct1; ct1i_last=ct1i;
    ct2_last=ct2; ct2i_last=ct2i;
    ct3_last=ct3; ct3i_last=ct3i;
    ct1b_last=ct1b; ct1bi_last=ct1bi;
  }
  
  if(verbose>2) {
    printf("AUC 0-%g:\n", t_last);
    printf(" ca1i := %g\n", ca1i);
    printf(" ca2i := %g\n", ca2i);
    printf(" ct1i := %g\n", ct1i_last);
    printf(" ct2i := %g\n", ct2i_last);
    printf(" ct3i := %g\n", ct3i_last);
    printf(" ct1bi := %g\n", ct1bi_last);
  }
 
  return 0;
}

◆ simC4DIvs()

int simC4DIvs	(	double *	t,
		double *	ca1,
		double *	ca2,
		double *	cb,
		int	nr,
		double	k1,
		double	k2,
		double	k3,
		double	k4,
		double	k5,
		double	k6,
		double	k7,
		double	km,
		double	k1b,
		double	k2b,
		double	f,
		double	vb,
		double	fa,
		double *	scpet,
		double *	sct1,
		double *	sct2,
		double *	sct3,
		double *	sct1b,
		double *	sctab,
		double *	sctvb,
		int	verbose )

Simulates tissue TAC using dual-input tissue compartment model (1-3 compartments in series for tracer1, and 1 compartment for tracer2) at plasma TAC times, considering also contribution of arterial and venous vasculature, and transfer of tracer1 to tracer2. The units of rate constants must be related to the time unit; 1/min and min, or 1/sec and sec. If blood flow is set to 0, function assumes that f>>k1, and Cvb=Cab. Reference: TPCMOD0001 Appendix B. Tested with program p2t_di -series.

Returns: Function returns 0 when successful, else a value >= 1.

See also: simC3s, simC3p, simC3vs, simC3vp, simC2l, simC2vl, simC3vpKLoss, simRTCM, simSRTM, simTRTM, simHuangmet, simTPCMOD0009c, simMBF, simC1, simC3DIvs, simC4DIvp, simDispersion, simOxygen

Parameters

t	Array of time values
ca1	Array of arterial plasma activities of tracer1 (parent tracer)
ca2	Array of arterial plasma activities of tracer2 (metabolite)
cb	Array of (total) arterial blood activities
nr	Number of values in TACs
k1	Rate constant of the model for tracer1 (from plasma to C1)
k2	Rate constant of the model for tracer1 (from C1 to plasma)
k3	Rate constant of the model for tracer1 (from C1 to C2)
k4	Rate constant of the model for tracer1 (from C2 to C1)
k5	Rate constant of the model for tracer1 (from C2 to C3)
k6	Rate constant of the model for tracer1 (from C3 to C2)
k7	Rate constant of the model for tracer1 (from C3 to plasma)
km	Rate constant of the model (from tracer1 in C1 to tracer2 in C4)
k1b	Rate constant of the model for tracer2 (from plasma to C4)
k2b	Rate constant of the model for tracer2 (from C4 to plasma)
f	Blood flow; if 0, function assumes that f>>k1, and Cvb=Cab.
vb	Vascular volume fraction
fa	Arterial fraction of vascular volume
scpet	Pointer for TAC array to be simulated; must be allocated
sct1	Pointer for 1st tracer1 compartment TAC, or NULL if not needed
sct2	Pointer for 2nd tracer1 compartment TAC, or NULL if not needed
sct3	Pointer for 3rd tracer1 compartment TAC, or NULL if not needed
sct1b	Pointer for 1st tracer2 compartment TAC, or NULL if not needed
sctab	Pointer for arterial TAC in tissue, or NULL if not needed
sctvb	Pointer for venous TAC in tissue, or NULL if not needed
verbose	Verbose level; if zero, then nothing is printed into stdout or stderr

Definition at line 1724 of file simulate.c.

  {
  int i;
  double b, c, d, e, pt, qt, rt, dt2, va, vv;
  double ca1i, ca1_last, ca2i, ca2_last, t_last, dct, cvb;
  double ct1, ct1_last, ct2, ct2_last, ct3, ct3_last;
  double ct1i, ct1i_last, ct2i, ct2i_last, ct3i, ct3i_last;
  double ct1b, ct1b_last, ct1bi, ct1bi_last;
 
 
  if(verbose>0) {
    printf("simC4DIvs()\n");
    if(verbose>1) {
      printf("  k1 := %g\n", k1);
      printf("  k2 := %g\n", k2);
      printf("  k3 := %g\n", k3);
      printf("  k4 := %g\n", k4);
      printf("  k5 := %g\n", k5);
      printf("  k6 := %g\n", k6);
      printf("  k7 := %g\n", k7);
      printf("  km := %g\n", km);
      printf("  k1b := %g\n", k1b);
      printf("  k2b := %g\n", k2b);
      printf("  vb := %g\n", vb);
      printf("  fa := %g\n", fa);
      printf("  f := %g\n", f);
    }
  }
 
  /* Check for data */
  if(nr<2) return 1;
  if(scpet==NULL) return 2;
 
  /* Check parameters */
  if(k1<0.0 || k1b<0.0) return 3;
  if(vb<0.0 || vb>=1.0) return 4;
  if(fa<0.0 || fa>1.0) return 5;
  va=fa*vb; vv=(1.0-fa)*vb;
 
  /* Calculate curves */
  t_last=0.0; if(t[0]<t_last) t_last=t[0];
  ca1i=ca1_last=ca2i=ca2_last=0.0;
  ct1_last=ct2_last=ct3_last=ct1i_last=ct2i_last=ct3i_last=ct1b_last=
  ct1bi_last=0.0;
  ct1=ct2=ct3=ct1b=ct1i=ct2i=ct3i=ct1bi=0.0;
  for(i=0; i<nr; i++) {
    /* delta time / 2 */
    dt2=0.5*(t[i]-t_last);
    /* calculate values */
    if(dt2<0.0) {
      return 5;
    } else if(dt2>0.0) {
      /* arterial integrals */
      ca1i+=(ca1[i]+ca1_last)*dt2;
      ca2i+=(ca2[i]+ca2_last)*dt2;
      //printf("ca1[%d]=%g int=%g\n", i, ca1[i], ca1i);
      //printf("ca2[%d]=%g int=%g\n", i, ca2[i], ca2i);
      /* partial results */
      b=ct1i_last+dt2*ct1_last;
      c=ct2i_last+dt2*ct2_last;
      d=ct3i_last+dt2*ct3_last;
      e=ct1bi_last+dt2*ct1b_last;
      pt=k6+k7;
      qt=k4+k5-(k5*k6*dt2)/(1.0+pt*dt2);
      rt=k2+k3+km-(k3*k4*dt2)/(1.0+qt*dt2);
      /* 1st tissue compartment and its integral */
      ct1 = (k1/(1.0+rt*dt2))*ca1i
    - (rt/(1.0+rt*dt2))*b
          + (k4/((1.0+qt*dt2)*(1.0+rt*dt2)))*c
          + ((k4*k6*dt2)/((1.0+pt*dt2)*(1.0+qt*dt2)*(1.0+rt*dt2)))*d;
      ct1i = ct1i_last + dt2*(ct1_last+ct1);
      /* 2nd tissue compartment and its integral */
      ct2 = (k3/(1.0+qt*dt2))*ct1i
          - (qt/(1.0+qt*dt2))*c
    + (k6/((1.0+pt*dt2)*(1.0+qt*dt2)))*d;
      ct2i = ct2i_last + dt2*(ct2_last+ct2);
      /* 3rd tissue compartment and its integral */
      ct3 = (k5/(1.0+pt*dt2))*ct2i
          - (pt/(1.0+pt*dt2))*d;
      ct3i = ct3i_last + dt2*(ct3_last+ct3);
      /* 4th tissue compartment (the 1st for tracer 2) and its integral */
      ct1b = (k1b/(1.0+k2b*dt2))*ca2i
           - (k2b/(1.0+k2b*dt2))*e
           + (km/(1.0+k2b*dt2))*ct1i;
      ct1bi = ct1bi_last + dt2*(ct1b_last+ct1b);
    }
    /* Venous curve */
    if(f>0.) {
      dct = k1*ca1[i] - k2*ct1 - k7*ct3 + k1b*ca2[i] - k2b*ct1b;
      cvb = cb[i] - dct/f;
    } else cvb=cb[i];
    /* copy values to argument arrays; set very small values to zero */
    scpet[i]= va*cb[i] + vv*cvb + (1.0-vb)*(ct1+ct2+ct3+ct1b);
    if(fabs(scpet[i])<1.0e-12) scpet[i]=0.0;
    if(sct1!=NULL) {
      sct1[i]=(1.0-vb)*ct1; if(fabs(sct1[i])<1.0e-12) sct1[i]=0.0;}
    if(sct2!=NULL) {
      sct2[i]=(1.0-vb)*ct2; if(fabs(sct2[i])<1.0e-12) sct2[i]=0.0;}
    if(sct3!=NULL) {
      sct3[i]=(1.0-vb)*ct3; if(fabs(sct3[i])<1.0e-12) sct3[i]=0.0;}
    if(sct1b!=NULL) {
      sct1b[i]=(1.0-vb)*ct1b; if(fabs(sct1b[i])<1.0e-12) sct1b[i]=0.0;}
    if(sctab!=NULL) {
      sctab[i]=va*cb[i]; if(fabs(sctab[i])<1.0e-12) sctab[i]=0.0;}
    if(sctvb!=NULL) {
      sctvb[i]=vv*cvb; if(fabs(sctvb[i])<1.0e-12) sctvb[i]=0.0;}
    /* prepare to the next loop */
    t_last=t[i]; ca1_last=ca1[i]; ca2_last=ca2[i];
    ct1_last=ct1; ct1i_last=ct1i;
    ct2_last=ct2; ct2i_last=ct2i;
    ct3_last=ct3; ct3i_last=ct3i;
    ct1b_last=ct1b; ct1bi_last=ct1bi;
  }
  
  if(verbose>2) {
    printf("AUC 0-%g:\n", t_last);
    printf(" ca1i := %g\n", ca1i);
    printf(" ca2i := %g\n", ca2i);
    printf(" ct1i := %g\n", ct1i_last);
    printf(" ct2i := %g\n", ct2i_last);
    printf(" ct3i := %g\n", ct3i_last);
    printf(" ct1bi := %g\n", ct1bi_last);
  }
 
  return 0;
}

◆ simDispersion()

int simDispersion	(	double *	x,
		double *	y,
		int	n,
		double	tau1,
		double	tau2,
		double *	tmp )

Simulate the effect of dispersion on a time-activity curve.

Returns: Returns 0 when successful, otherwise <>0.

See also: simC3s, simC3p, simC3vs, simC3vp, simC2l, simC2vl, simC3vpKLoss, simRTCM, simSRTM, simTRTM, simHuangmet, simTPCMOD0009c, simMBF, simC1, simC3DIvs, simC4DIvp, simC4DIvs, simOxygen

Parameters

x	Array of sample times.
y	Array of sample values, which will be replaced here by dispersion added values.
n	Nr of samples.
tau1	First dispersion time constant (zero if no dispersion); in same time unit as sample times.
tau2	2nd dispersion time constant (zero if no dispersion); in same time unit as sample times.
tmp	Array for temporary data, for at least n samples; enter NULL to let function to allocate and free the temporary space.

Definition at line 1911 of file simulate.c.

  {
  /* Check input */
  if(x==NULL || y==NULL || n<2) return 1;
  if(tau1<0.0 || tau2<0.0) return 2;
 
  /* Allocate memory if not allocated by user */
  double *buf;
  if(tmp!=NULL) buf=tmp; else buf=(double*)malloc(n*sizeof(double));
  if(buf==NULL) return 3;
 
  /* First dispersion */
  if(tau1>0.0) {
    double k=1.0/tau1;
    int ret=simC1(x, y, n, k, k, buf);
    if(ret!=0) {
      if(tmp==NULL) free(buf);
      return 100+ret;
    }
    for(int i=0; i<n; i++) y[i]=buf[i];
  }
 
  /* Second dispersion */
  if(tau2>0.0) {
    double k=1.0/tau2;
    int ret=simC1(x, y, n, k, k, buf);
    if(ret!=0) {
      if(tmp==NULL) free(buf);
      return 200+ret;
    }
    for(int i=0; i<n; i++) y[i]=buf[i];
  }
 
  if(tmp==NULL) free(buf);
  return 0;
}

Referenced by fitEvaltac().

◆ simHuangmet()

int simHuangmet	(	double *	t,
		double *	ctot,
		int	nr,
		double	k01,
		double	k12,
		double	k21,
		double	k03,
		double	k34,
		double	k43,
		double *	c0,
		double *	c1,
		double *	c3 )

Simulation of TACs of parent tracer, and 1-2 of its metabolites in plasma using Huang's compartmental model.

The units of model parameters must be related to the sample time unit; 1/min and min, or 1/sec and sec.

Pointers to memory for output TACs must be specified, or NULL if TAC is not needed.

Returns: Returns 0, if ok.

See also: simC3s, simC3p, simC3vs, simC3vp, simC2l, simC2vl, simC3vpKLoss, simRTCM, simSRTM, simTRTM, simTPCMOD0009c, simMBF, simC1, simC3DIvs, simC4DIvp, simC4DIvs, simDispersion, simOxygen

Parameters

t	Input: Sample times (preferably with short intervals)
ctot	Input: Measured total plasma TAC
nr	Input: Nr of samples
k01	Input: Model parameters
k12	Input: Model parameters
k21	Input: Model parameters
k03	Input: Model parameters
k34	Input: Model parameters
k43	Input: Model parameters
c0	Output: unchanged (parent) tracer TAC
c1	Output: TAC of the 1st metabolite
c3	Output: TAC of the 2nd metabolite

Definition at line 1054 of file simulate.c.

  {
  int i;
  double dt2, t_last, ictot, ctot_last;
  double c0_, c1_, c2_, c3_, c4_;
  double ic0_, ic1_, ic2_, ic3_, ic4_;
  double c0_last, c1_last, c2_last, c3_last, c4_last;
  double ic0_last, ic1_last, ic2_last, ic3_last, ic4_last;
  double a, b, am1, am2, am3, am4;
 
 
  /* Check input */
  if(t==NULL || ctot==NULL || nr<2) return(1);
  if(k01<0 || k12<0 || k21<0 || k03<0 || k34<0 || k43<0) return(2);
  if(t[0]<0.0) return(3);
 
  /* Compute the TACs */
  t_last=0.0; if(t[0]<t_last) t_last=t[0];
  ictot=ctot_last=0.0;
  c0_=c0_last=ic0_=ic0_last=0.0;
  c1_=c1_last=ic1_=ic1_last=0.0;
  c2_=c2_last=ic2_=ic2_last=0.0;
  c3_=c3_last=ic3_=ic3_last=0.0;
  c4_=c4_last=ic4_=ic4_last=0.0;
  for(i=0; i<nr; i++) {
    /* delta time / 2 */
    dt2=0.5*(t[i]-t_last); if(dt2<0.0) return(5);
    if(dt2>0.0) {
      /* Compute temp constants */
      a=k01+k12-(k12*k21*dt2/(1.0+dt2*k21));
      b=k03+k34-(k34*k43*dt2/(1.0+dt2*k43));
      am1=ic1_last+dt2*c1_last;
      am2=ic2_last+dt2*c2_last;
      am3=ic3_last+dt2*c3_last;
      am4=ic4_last+dt2*c4_last;
    
      /* Compute the "input" i.e. ctot integral */
      ictot+=(ctot[i]+ctot_last)*dt2;
      /* Compute C1(t) and its integral */
      c1_= ( k01*(1.0-k03*dt2/(1.0+dt2*b))*ictot
            -(a-k01*k03*dt2/(1.0+dt2*b))*am1
            +(k21/(1.0+dt2*k21))*am2
            -(k01/(1.0+dt2*b))*am3
            -(k01*k43*dt2/((1.0+dt2*b)*(1.0+dt2*k43)))*am4
           ) / ( 1.0+dt2*(a-k01*k03*dt2/(1.0+dt2*b)) );
      ic1_= ic1_last + dt2*(c1_+c1_last);
      /* Compute C2(t) and its integral */
      c2_= (k12*ic1_-k21*am2)/(1.0+dt2*k21);
      ic2_= ic2_last + dt2*(c2_+c2_last);
 
      /* Compute C3(t) and its integral */
      c3_= ( k03*(1.0-k01*dt2/(1.0+dt2*a))*ictot
            -(b-k01*k03*dt2/(1.0+dt2*a))*am3
            +(k43/(1.0+dt2*k43))*am4
            -(k03/(1.0+dt2*a))*am1
            -(k03*k21*dt2/((1.0+dt2*a)*(1.0+dt2*k21)))*am2
           ) / ( 1.0+dt2*(b-k01*k03*dt2/(1.0+dt2*a)) );
      ic3_= ic3_last + dt2*(c3_+c3_last);
      /* Compute C4(t) and its integral */
      c4_= (k34*ic3_-k43*am4)/(1.0+dt2*k43);
      ic4_= ic4_last + dt2*(c4_+c4_last);
 
      /* Compute the C0(t) */
      c0_=ctot[i]-c1_-c3_; /*if(c0_<0.0) return(-1);*/
    }
    /* Set output data */
    if(c0) c0[i]=c0_; 
    if(c1) c1[i]=c1_; 
    if(c3) c3[i]=c3_;
    /* Prepare for the next sample */
    c0_last=c0_; c1_last=c1_; c2_last=c2_; c3_last=c3_; c4_last=c4_;
    ic0_last=ic0_; ic1_last=ic1_; ic2_last=ic2_; ic3_last=ic3_; ic4_last=ic4_;
    ctot_last=ctot[i]; t_last=t[i];
  } /* next sample */
 
  return(0);
}

◆ simMBF()

int simMBF	(	double *	t,
		double *	ci,
		int	nr,
		double	k1,
		double	k2,
		double	Vfit,
		double *	ct )

Simulate myocardial tissue TAC using Iida's compartment model. Memory for ct must be allocated in the calling program. The units of rate constants must be related to the time unit; 1/min and min, or 1/sec and sec.

Returns: 0 when successful, else a value >= 1.

See also: simC3s, simC3p, simC3vs, simC3vp, simC2l, simC2vl, simC3vpKLoss, simRTCM, simSRTM, simTRTM, simHuangmet, simTPCMOD0009c, simC1, simC3DIvs, simC4DIvp, simC4DIvs, simDispersion, simOxygen

Parameters

t	Array of time values
ci	Input activities
nr	Number of values in TACs
k1	Apparent k1
k2	Apparent k2
Vfit	Vfit
ct	Pointer for TAC array to be simulated; must be allocated

Definition at line 1253 of file simulate.c.

  {
  int i;
  double dt2;
  double cii, ci_last, t_last;
  double ct_last, cti, cti_last;
 
 
  /* Check for data */
  if(nr<2) return(1);
  if(ct==NULL) return(2);
 
  /* Calculate curves */
  t_last=0.0; cii=ci_last=0.0;
  cti=ct_last=cti_last=0.0;
  for(i=0; i<nr; i++) {
    /* delta time / 2 */
    dt2=0.5*(t[i]-t_last);
    /* calculate values */
    if(dt2<0.0) {
      return(5);
    } else if(dt2>0.0) {
      /* input integral */
      cii+=(ci[i]+ci_last)*dt2;
      /* Tissue compartment and its integral */
      ct[i] = (Vfit*ci[i] + k1*cii - k2*(cti_last+dt2*ct_last)) / (1.0 + dt2*k2);
      cti = cti_last + dt2*(ct_last+ct[i]);
    }
    /* set very small values to zero */
    if(fabs(ct[i])<1.0e-12) ct[i]=0.0;
    /* prepare to the next loop */
    t_last=t[i]; ci_last=ci[i];
    ct_last=ct[i]; cti_last=cti;
  }
  return(0);
}

◆ simOxygen()

int simOxygen	(	double *	t,
		double *	ca1,
		double *	ca2,
		double *	ca1i,
		double *	ca2i,
		const int	n,
		const double	k1a,
		const double	k2a,
		const double	km,
		const double	k1b,
		const double	k2b,
		const double	vb,
		const double	fa,
		double *	scpet,
		double *	sct1,
		double *	sct2,
		double *	sctab,
		double *	sctvb1,
		double *	sctvb2,
		double *	scvb1,
		double *	scvb2,
		const int	verbose )

Simulate tissue and venous blood TACs using dual-input compartment model for [O-15]O2 (one tissue compartment for [O-15]O2, and another tissue compartment for its metabolite [O-15]H2O).

The units of rate constants must be related to the time unit of the data; 1/min and min, or 1/sec and sec.

Returns: Function returns 0 when successful, else a value >= 1.

Author: Vesa Oikonen

See also: simC3s, simC3p, simC3vs, simC3vp, simC2l, simC2vl, simC3vpKLoss, simRTCM, simSRTM, simTRTM, simHuangmet, simTPCMOD0009c, simMBF, simC1, simC3DIvs, simC4DIvp, simC4DIvs, simDispersion

Parameters

t	Array of sample times
ca1	Array of arterial blood activities of tracer1 ([O-15]O2)
ca2	Array of arterial blood activities of tracer2 ([O-15]H2O)
ca1i	Array of AUC 0-t of arterial tracer1 activities; NULL if not available
ca2i	Array of AUC 0-t of arterial tracer2 activities; NULL if not available
n	Nr of samples (array lengths)
k1a	Rate constant of the model for tracer1 (from blood to C1)
k2a	Rate constant of the model for tracer1 (from C1 to blood)
km	Rate constant of the model (from tracer1 in C1 to tracer2 in C2)
k1b	Rate constant of the model for tracer2 (from blood to C2)
k2b	Rate constant of the model for tracer2 (from C2 to blood)
vb	Vascular volume fraction [0-1)
fa	Arterial fraction of vascular volume [0-1]
scpet	Pointer for TTAC array to be simulated; allocate in the calling program or set to NULL if not needed
sct1	Simulated TAC of tracer1 in tissue; allocate in the calling program or set to NULL if not needed
sct2	Simulated TAC of tracer2 in tissue; allocate in the calling program or set to NULL if not needed
sctab	Total arterial contribution to PET TTAC; allocate in the calling program or set to NULL if not needed
sctvb1	Venous tracer1 contribution to PET TAC; allocate in the calling program or set to NULL if not needed
sctvb2	Venous tarcer1 contribution to PET TAC; allocate in the calling program or set to NULL if not needed
scvb1	Venous BTAC of tracer1; allocate in the calling program or set to NULL if not needed
scvb2	Venous BTAC of tracer2; allocate in the calling program or set to NULL if not needed
verbose	Verbose level; if zero, then nothing is printed into stdout or stderr

Definition at line 1978 of file simulate.c.

  {
  if(verbose>0) {
    printf("simOxygen()\n");
    if(verbose>1) {
      printf("  k1a := %g\n", k1a);
      printf("  k2a := %g\n", k2a);
      printf("  km := %g\n", km);
      printf("  k1b := %g\n", k1b);
      printf("  k2b := %g\n", k2b);
      printf("  vb := %g\n", vb);
      printf("  fa := %g\n", fa);
      printf("  n := %d\n", n);
    }
  }
 
  /* Check for data */
  if(n<2) return 1;
  if(t==NULL) return 2;
  if(ca1==NULL || ca2==NULL) return 3;
 
  /* Check parameters */
  if(k1a<0.0 || k1b<0.0 || k2a<0.0 || k2b<0.0) return(4);
  if(vb<0.0 || vb>=1.0) return(5);
  if(fa<0.0 || fa>1.0) return(6);
  double va=fa*vb;       // arterial volume fraction in tissue
  double vv=(1.0-fa)*vb; // venous volume fraction in tissue
 
  /* Set initial condition */
  double t_last=0.0; // previous sample time
  if(t[0]<t_last) t_last=t[0];
  /* Concentrations, integrals, and previous values are zero */
  double cba1i=0.0, cba1_last=0.0;
  double cba2i=0.0, cba2_last=0.0;
  double ct1=0.0, ct1_last=0.0, ct1i=0.0, ct1i_last=0.0;
  double ct2=0.0, ct2_last=0.0, ct2i=0.0, ct2i_last=0.0;
  double cvb1=0.0, cvb2=0.0;
 
  /* Calculate curves */
  double p, q;
  double dt2; // delta t / 2
  for(int i=0; i<n; i++) {
    dt2=0.5*(t[i]-t_last);
    if(dt2>0.0) {
      /* arterial integrals */
      if(ca1i!=NULL) cba1i=ca1i[i]; else cba1i+=(ca1[i]+cba1_last)*dt2;
      if(ca2i!=NULL) cba2i=ca2i[i]; else cba2i+=(ca2[i]+cba2_last)*dt2;
      /* partial results */
      p=ct1i_last+dt2*ct1_last;
      q=ct2i_last+dt2*ct2_last;
      /* 1st tissue compartment and its integral */
      ct1 = (k1a*cba1i - (k2a+km)*p) / (1.0 + dt2*(k2a+km));
      ct1i = ct1i_last + dt2*(ct1_last+ct1);
      /* 2nd tissue compartment and its integral */
      ct2 = (km*ct1i + k1b*cba2i - k2b*q) / (1.0 + dt2*k2b);
      ct2i = ct2i_last + dt2*(ct2_last+ct2);
    }
    /* Venous BTACs */
    if(k1a>0.0 && k2a>0.0) cvb1=ct1/(k1a/k2a);
    else if(k2a>0.0) cvb1=0.0; else cvb1=ca1[i];
    if(k1b>0.0 && k2b>0.0) cvb2=ct2/(k1b/k2b);
    else if(k2b>0.0) cvb2=0.0; else cvb2=ca2[i];
    /* copy values to argument arrays; set very small values to zero */
    if(scpet!=NULL) {
      scpet[i]= va*(ca1[i]+ca2[i]) + vv*(cvb1+cvb2) + (1.0-vb)*(ct1+ct2);
      if(fabs(scpet[i])<1.0e-12) scpet[i]=0.0;
    }
    if(sct1!=NULL) {
      sct1[i]=(1.0-vb)*ct1; 
      if(fabs(sct1[i])<1.0e-12) sct1[i]=0.0;
    }
    if(sct2!=NULL) {
      sct2[i]=(1.0-vb)*ct2; 
      if(fabs(sct2[i])<1.0e-12) sct2[i]=0.0;
    }
    if(sctab!=NULL) {
      sctab[i]=va*(ca1[i]+ca2[i]); 
      if(fabs(sctab[i])<1.0e-12) sctab[i]=0.0;
    }
    if(sctvb1!=NULL) {
      sctvb1[i]=vv*cvb1; 
      if(fabs(sctvb1[i])<1.0e-12) sctvb1[i]=0.0;
    }
    if(sctvb2!=NULL) {
      sctvb2[i]=vv*cvb2; 
      if(fabs(sctvb2[i])<1.0e-12) sctvb2[i]=0.0;
    }
    if(scvb1!=NULL) scvb1[i]=cvb1;
    if(scvb2!=NULL) scvb2[i]=cvb2;
    /* prepare for the next loop */
    t_last=t[i]; 
    cba1_last=ca1[i]; cba2_last=ca2[i];
    ct1_last=ct1; ct1i_last=ct1i;
    ct2_last=ct2; ct2i_last=ct2i;
  } // next sample
 
  if(verbose>2) {
    printf("AUC 0-%g:\n", t_last);
    printf(" cba1i := %g\n", cba1i);
    printf(" cba2i := %g\n", cba2i);
    printf(" ct1i := %g\n", ct1i_last);
    printf(" ct2i := %g\n", ct2i_last);
  }
 
  return 0;
}

◆ simRTCM()

int simRTCM	(	double *	t,
		double *	cr,
		int	nr,
		double	R1,
		double	k2,
		double	k3,
		double	k4,
		double *	ct,
		double *	cta,
		double *	ctb )

Simulates tissue TAC using reference tissue compartment model (original) and reference region TAC, at reference region TAC times.

Memory for ct must be allocated in the calling program. To retrieve the separate tissue compartment TACs, pointer to allocated memory for cf and/or cb can be given; if compartmental TACs are not required, NULL pointer can be given instead.

The units of rate constants must be related to the time unit; 1/min and min, or 1/sec and sec.

Returns: Function returns 0 when successful, else a value >= 1.

See also: simC3s, simC3p, simC3vs, simC3vp, simC2l, simC2vl, simC3vpKLoss, simSRTM, simTRTM, simHuangmet, simTPCMOD0009c, simMBF, simC1, simC3DIvs, simC4DIvp, simC4DIvs, simDispersion, simOxygen

Parameters

t	Array of time values
cr	Reference region activities
nr	Number of values in TACs
R1	Ratio K1/K1'
k2	Rate constant of the model
k3	Rate constant of the model
k4	Rate constant of the model
ct	Pointer for TAC array to be simulated; must be allocated
cta	Pointer for 1st compartment TAC to be simulated, or NULL
ctb	Pointer for 2nd compartment TAC to be simulated, or NULL

Definition at line 835 of file simulate.c.

  {
  int i;
  double f, b, w, dt2;
  double cri, cr_last, t_last;
  double cf, cf_last, cb, cb_last;
  double cfi, cfi_last, cbi, cbi_last;
 
 
  /* Check for data */
  if(nr<2) return 1;
  if(ct==NULL) return 2;
 
  /* Calculate curves */
  t_last=0.0; if(t[0]<t_last) t_last=t[0];
  cri=cr_last=0.0; cf_last=cb_last=cfi_last=cbi_last=cf=cb=cfi=cbi=0.0;
  for(i=0; i<nr; i++) {
    /* delta time / 2 */
    dt2=0.5*(t[i]-t_last);
    /* calculate values */
    if(dt2<0.0) {
      return 5;
    } else if(dt2>0.0) {
      /* reference integral */
      cri+=(cr[i]+cr_last)*dt2;
      /* partial results */
      f=cfi_last+dt2*cf_last;
      b=cbi_last+dt2*cb_last;
      w=k2 + k3 + k2*k4*dt2;
      /* 1st tissue compartment and its integral */
      cf = ( (1.0 + k4*dt2)*(R1*cr[i] + k2*cri) + k4*b - w*f ) /
           ( 1.0 + dt2*(w+k4) );
      cfi = cfi_last + dt2*(cf_last+cf);
      /* 2nd tissue compartment and its integral */
      cb = (k3*cfi - k4*b) / (1.0 + k4*dt2);
      cbi = cbi_last + dt2*(cb_last+cb);
    }
    /* copy values to argument arrays; set very small values to zero */
    ct[i]=cf+cb; if(fabs(ct[i])<1.0e-12) ct[i]=0.0;
    if(cta!=NULL) {cta[i]=cf; if(fabs(cta[i])<1.0e-12) cta[i]=0.0;}
    if(ctb!=NULL) {ctb[i]=cb; if(fabs(ctb[i])<1.0e-12) ctb[i]=0.0;}
    /* prepare to the next loop */
    t_last=t[i]; cr_last=cr[i];
    cf_last=cf; cfi_last=cfi;
    cb_last=cb; cbi_last=cbi;
  }
 
  return 0;
}

◆ simSRTM()

int simSRTM	(	double *	t,
		double *	cr,
		int	nr,
		double	R1,
		double	k2,
		double	BP,
		double *	ct )

Simulates tissue TAC using reference tissue compartment model (simplified) and reference region TAC, at reference region TAC times.

Memory for ct must be allocated in the calling program.

The units of rate constants must be related to the time unit; 1/min and min, or 1/sec and sec.

Returns: Function returns 0 when successful, else a value >= 1.

See also: simC3s, simC3p, simC3vs, simC3vp, simC2l, simC2vl, simC3vpKLoss, simRTCM, simTRTM, simHuangmet, simTPCMOD0009c, simMBF, simC1, simC3DIvs, simC4DIvp, simC4DIvs, simDispersion, simOxygen

Parameters

t	Array of time values
cr	Reference region activities
nr	Number of values in TACs
R1	Ratio K1/K1'
k2	Rate constant of the model
BP	Binding potential
ct	Pointer for TAC array to be simulated; must be allocated

Definition at line 919 of file simulate.c.

  {
  int i;
  double dt2;
  double cri, cr_last, t_last;
  double ct_last, cti, cti_last;
 
 
  /* Check for data */
  if(nr<2) return 1;
  if(ct==NULL) return 2;
 
  /* Calculate curves */
  t_last=0.0; if(t[0]<t_last) t_last=t[0];
  cri=cr_last=0.0; cti=ct_last=cti_last=0.0;
  for(i=0; i<nr; i++) {
    /* delta time / 2 */
    dt2=0.5*(t[i]-t_last);
    /* calculate values */
    if(dt2<0.0) {
      return 5;
    } else if(dt2>0.0) {
      /* reference integral */
      cri+=(cr[i]+cr_last)*dt2;
      /* Tissue compartment and its integral */
      ct[i] = ( R1*cr[i] + k2*cri - (k2/(1.0+BP))*(cti_last+dt2*ct_last) ) /
              ( 1.0 + dt2*(k2/(1.0+BP)) );
      cti = cti_last + dt2*(ct_last+ct[i]);
    }
    /* set invalid or very small values to zero */
    if(!(fabs(ct[i])>=1.0e-12)) ct[i]=0.0;
    /* prepare to the next loop */
    t_last=t[i]; cr_last=cr[i];
    ct_last=ct[i]; cti_last=cti;
  }
 
  return 0;
}

◆ simTPCMOD0009c()

int simTPCMOD0009c	(	double *	t,
		double *	ctot,
		int	nr,
		double	km,
		double	k1m,
		double	k2m,
		double	k3m,
		double	k4m,
		double *	ca,
		double *	cm )

Simulate parent tracer TAC using plasma metabolite model TPCMOD0009C, https://www.turkupetcentre.net/reports/tpcmod0009_app_c.pdf

Returns: Returns 0 if successful.

See also: simC3s, simC3p, simC3vs, simC3vp, simC2l, simC2vl, simC3vpKLoss, simRTCM, simSRTM, simTRTM, simHuangmet, simMBF, simC1, simC3DIvs, simC4DIvp, simC4DIvs, simDispersion, simOxygen

Parameters

t	Sample times
ctot	Total plasma TAC
nr	Sample number
km	km
k1m	k1m
k2m	k2m
k3m	k3m
k4m	k4m
ca	Pointer to array where parent tracer TAC will be written; NULL, if not needed.
cm	Pointer to array where metabolized tracer TAC will be written; NULL, if not needed.

Definition at line 1165 of file simulate.c.

  {
  int i;
  double t_last, dt2;
  double ctoti, ctot_last;
  double a, b;
  double ct1m, ct1mi, ct1m_last, ct1mi_last;
  double ct2m, ct2mi, ct2m_last, ct2mi_last;
  double cpm, cpmi, cpm_last, cpmi_last;
  
 
  /* Check for data */
  if(nr<2) return 1;
  if(t==NULL || ctot==NULL || ca==NULL) return 2;
 
  /* Calculate curves */
  t_last=0.0; if(t[0]<t_last) t_last=t[0]; 
  ctoti=ctot_last=0.0;
  ct1m_last=ct1mi_last=ct2m_last=ct2mi_last=cpm_last=cpmi_last=0.0;
  //ct1=ct2=ct3=ct1i=ct2i=ct3i=0.0;
  for(i=0; i<nr; i++) {
    /* delta time / 2 */
    dt2=0.5*(t[i]-t_last);
    /* calculate values */
    if(dt2<0.0) {
      return 5;
    } else {
      /* arterial integral */
      ctoti+=(ctot[i]+ctot_last)*dt2;
      /* partial results */
      a=k4m/(1.0+k4m*dt2);
      b=(k1m-km)/(1.0+dt2*(k1m+k3m-k3m*a*dt2));
      /* 1st tissue compartment and its integral */
      ct1m = (km*ctoti - k2m*(1.0-dt2*b)*(ct1mi_last+dt2*ct1m_last)
             + b*(cpmi_last+dt2*cpm_last) + a*b*dt2*(ct2mi_last+dt2*ct2m_last)
       ) / (1.0 + dt2*k2m*(1.0-dt2*b));
      ct1mi = ct1mi_last + dt2*(ct1m_last+ct1m);
      /* Metabolite plasma compartment and its integral */
      cpm = (k2m*ct1mi + a*(ct2mi_last+dt2*ct2m_last)
             - (k1m+k3m-k3m*dt2*a)*(cpmi_last+dt2*cpm_last)
            ) / (1.0 + dt2*(k1m+k3m-k3m*dt2*a));
      cpmi = cpmi_last + dt2*(cpm_last+cpm);
      /* 2nd tissue compartment and its integral */
      ct2m = (k3m*cpmi - k4m*(ct2mi_last+dt2*ct2m_last)) / (1.0 + dt2*k4m);
      ct2mi = ct2mi_last + dt2*(ct2m_last+ct2m);
    }
    /* copy values to argument arrays; set very small values to zero */
    if(ca!=NULL) {ca[i]=ctot[i]-cpm; if(fabs(ca[i])<1.0e-12) ca[i]=0.0;}
    if(cm!=NULL) {cm[i]=cpm; if(fabs(cm[i])<1.0e-12) cm[i]=0.0;}
    /* prepare to the next loop */
    t_last=t[i]; ctot_last=ctot[i];
    ct1m_last=ct1m; ct1mi_last=ct1mi;
    ct2m_last=ct2m; ct2mi_last=ct2mi;
    cpm_last=cpm; cpmi_last=cpmi;
  } // next sample
  return 0;
}

◆ simTRTM()

int simTRTM	(	double *	t,
		double *	cr,
		int	nr,
		double	R1,
		double	k2,
		double	k3,
		double *	ct )

Simulates tissue TAC using reference tissue compartment model (transport limited in ref region) and reference region TAC, at reference region TAC times.

Memory for ct must be allocated in the calling program.

The units of rate constants must be related to the time unit; 1/min and min, or 1/sec and sec.

Returns: Function returns 0 when successful, else a value >= 1.

See also: simC3s, simC3p, simC3vs, simC3vp, simC2l, simC2vl, simC3vpKLoss, simRTCM, simSRTM, simHuangmet, simTPCMOD0009c, simMBF, simC1, simC3DIvs, simC4DIvp, simC4DIvs, simDispersion, simOxygen

Parameters

t	Array of time values
cr	Reference region activities
nr	Number of values in TACs
R1	Ratio K1/K1'
k2	Rate constant of the model
k3	Rate constant of the model
ct	Pointer for TAC array to be simulated; must be allocated

Definition at line 986 of file simulate.c.

  {
  int i;
  double dt2;
  double cri, cr_last, t_last;
  double ct_last, cti, cti_last;
 
 
  /* Check for data */
  if(nr<2) return 1;
  if(ct==NULL) return 2;
 
  /* Calculate curves */
  t_last=0.0; if(t[0]<t_last) t_last=t[0];
  cri=cr_last=0.0; cti=ct_last=cti_last=0.0;
  for(i=0; i<nr; i++) {
    /* delta time / 2 */
    dt2=0.5*(t[i]-t_last);
    /* calculate values */
    if(dt2<0.0) {
      return 5;
    } else if(dt2>0.0) {
      /* reference integral */
      cri+=(cr[i]+cr_last)*dt2;
      /* Tissue compartment and its integral */
      ct[i] = ( R1*cr[i] + R1*k3*cri - (k2+k3)*(cti_last+dt2*ct_last) ) /
              ( 1.0 + dt2*(k2+k3) );
      cti = cti_last + dt2*(ct_last+ct[i]);
    }
    /* set very small values to zero */
    if(fabs(ct[i])<1.0e-12) ct[i]=0.0;
    /* prepare to the next loop */
    t_last=t[i]; cr_last=cr[i];
    ct_last=ct[i]; cti_last=cti;
  }
 
  return 0;
}

Functions

Detailed Description

Function Documentation

◆ simC1()

◆ simC2l()

◆ simC2vl()

◆ simC3DIvs()

◆ simC3p()

◆ simC3s()

◆ simC3vp()

◆ simC3vpKLoss()

◆ simC3vs()

◆ simC4DIvp()

◆ simC4DIvs()

◆ simDispersion()

◆ simHuangmet()

◆ simMBF()

◆ simOxygen()

◆ simRTCM()

◆ simSRTM()

◆ simTPCMOD0009c()

◆ simTRTM()