Tracer Kinetic Methods in

Medical Physiology

Nieh A. Lassen, M.D. Will& Pal, 1Ph.D. lkprfment of C/infcaI PhysioIogv &pr&mt of W i a n c Bitp&@q WmpifsI Nm&?sey Cd&e ofMedic1he Copenhge~t. hnrnark arpd-rlt

b r k , Miw Jemy

@!&$&?*--'; Raven pres% New York

Contents

Canstmf Infusion M&hd (The S k w a PrincipIa 1

2 Flow of Flux by Constant Infusion and Constant Nmm~eonvdw 0ut;Aux (The Pidt Principle) 14

3 Fiow of Flux by h1w Injetion: OuW Mix- Henriqn- Hamitton Priwiple) 24

4 How of Plux by Bolus Injection: Inbt W n g (The krgncr BrZnoiple) 3B

5 Volume of Dis~ibution or USIS of a SuWmoe in a Closad System 50

7 VolumESplcw or MwdFIuar Ratio (Mam Tra&i Tim): l1. Bolus Injection 76

t o Compm~ta-

1 1 Multiple Zndhtws: Capillary P e m W f p

1 Constant Infusion Method (The Stewart Principle)

&mmi G N, (1- J. PAM 22:tS. The m f o r r ~ f&&irn of 9n indicator md dpwmbwm measmeapt of the dituth & u k the h l and mwt dwi- ous approach Ea mamring flow with a foreign suhstma~ But, as will k &awn im tbb chapter, tbia simple infusion me&& (stwfy-@a'dc metW) k b e t with &G difR~ultic9 3ng whp#h& mcirwlatioa of h & i W m d so forth as the f o m & mhw diEermt hIus iqWr"a~ methd (impuk re- s p m e m c h d ) to & GWW in subcquent dmptem. I d d , to perceive the c@% &lionship beWe.n &e two m e t h h as mrtlamtidy exp- in Shu 'atimulw r e p o n e the+ rcm" in C h p t m 4 a d 6 is a key ~ndurstamdk~ idbator methub in ,-*

-In& ge& pis1 that k tmphaskd is ob ksml identity k W e m tk concept of a flow (fluid warnpurr) and a flux (masa traf i~rt) . This thane will be diewed io wmc detail in tk first chapter and reprated in subsequent c h p m W e kw Qurrd it so d l to j ~ x t q m e flow and flux that w hwe cham to giw both k m ~ &&samt mtanin&-tWl tlow, d v t i v c l y , total flux aver a given cmm section or medqme surface. Aocording ta this temholqy tk d m or flux p unit area d WOSB seation of membrane d a c e msy be designated the flow d w i t y, and respctbdy, the flux d e n s i ~ y ~

Next WB discus mtthods, of pftsrmizq the inhion experimmt. ND 1mgW pmmbuhmry theoM& c h @ m on mrttriw, a x p n ~ ~ ~tamfom, and w forth wiU 1l given. Instead, we shall &vdo# the mathemalid wmpt&$ty in each chapter as tie need a r k in the oontezrt of actual situatibt~~. Thus we hqx to Mer convey the fnrct hat the+ s h p b methods require ady the most dnrentary algebraic o p r i u n s , and that the undwtmding of all the methais de- pmk m ~ s e on understanding a r l i t i o n s (e.g., nature of the indicator, mixing, recirdaticm) than on the mathemti- cal derivations.

1