technique using a single scintillation camera and

Transcription

1 Gut, 1983, 24, Gstric emptying in norml subjects reproducible technique using single scintilltion cmer nd computer system P J COLLINS, M HOROWITZ, D J COOK, P E HRDING, ND D J C SHERMN From the Division of Nucler Medicine, Institute of Medicl nd Veterinry Science, Endocrine Unit, Royl delide Hospitl nd the Deprtment of Medicine, University ofdelide, delide, South ustrli SUMMRY The gstric emptying of mied solid nd liquid mel ws ssessed in 24 norml subjects using single cmer/computer system which llowed continuous monitoring of both solids nd liquids. It ws shown tht vrition in tissue ttenution cused by the chnging depth of rdionuclide within the stomch ccounted for lrge errors in the mesurement of gstric emptying (ltertion in 5% emptying time of up to 65%). technique for the correction of ttenution is described which used fctors derived from lterl imge of the stomch. In ll subjects, solid emptying ws slower thn liquid emptying nd ws chrcterised by dely (lg period) which ws followed by liner emptying. Liquid emptying usully followed single eponentil pttern. The effect of physiologicl chnges induced by incresing the clorie content of the liquid component of the mel ws ssessed by giving either wter, 1% detrose or 25% detrose. Liquid emptying ws slowed nd the lg period of solid ws prolonged s the clorie content incresed. Reproducibility ws ssessed in 19 subjects. For the three groups studied (wter, 1% detrose, 25% detrose) the dy-to-dy vrition in gstric emptying ws not significnt for ny mesured prmeter, while sttisticlly significnt differences were present in solid nd liquid emptying between subjects nd groups. Rdionuclide methods re being used incresingly to study the gstric emptying of both solid nd liquid components of mel nd by these mens disorders of gstric emptying nd of the distribution of solid nd liquid components of mel within the stomch hve been shown. 1-8 nlysis of studies from different centres indictes indequte informtion in two importnt res. It hs been recognised by some groups9 1 tht the vrition in depth of rdionuclide within the stomch my result in significnt error in the mesurement of gstric emptying if no ttempt is mde to correct for gmm ry ttenution by the ptient's tissues. Previously reported correction techniques utilising either dul probe rectiliner scnner"' or single scintilltion cmer9 re ddress for correspondence: Professor D J C-Shermn, Deprtment of Medicine. University of delide. Royl delide Hospitl, delide. South ustrli 5. Received for publiction 25 Februry effective but suffer from infrequent time smpling of the dt. In the present study, technique for the correction of ttentution is described which utilised lterl imge of the stomch nd single cmer computer system, nd enbled continuous monitoring of the emptying of solid (chicken liver lbelled with technetium 99m sulphur colloid4 (99'Tc-SC)) nd liquid (diethyltriminepentcetic cid lbelled with indium 113m2 (ll3min-dtp)) Mny studies hve filed to define the reproducibility of gstric emptying studies within individul ptients. The present pper ssesses reproducibility during physiologicl studies to determine the effect of incresing the clorie content of the liquid component of the mel. Methods PHNTOM STUDIES ttenution coefficients These were obtined for 99mTc (14 kev) nd ll3min 1117 Gut: first published s /gut on 1 December Downloded from on 15 Jnury 219 by guest. Protected by copyright.

2 1118 (393 kev) by counting 37 MBq (lmci) source t vrious depths in lrge wter-bth plced on the collimtor surfce. Compton sctter 25 ml conicl flsk contining 37 MBq (1 mci) of 99mTc in 2 ml wter ws positioned 6 cm from the collimtor surfce in wter-bth nd 2 second imge ws tken in the 99mTc window (imge ): 18 MBq (-5 mci) of II3mIn ws then dded to the flsk nd 2 second imges were tken in the 99mTc nd II3mIn windows. region of interest obtined from imge ws used for ll three imges. The increse in counts in the 99mTc window resulting from the ddition of ll3min ws epressed s percentge of the counts in the ll3min window. PREPRTION OF SOLID MRKER ND LIQUID MRKER One gigbecquerel (27 mci) of 99mTc-SC ws injected into wing vein of live chicken, s described by Meyer et l.4 fter 2 minutes the chicken ws killed nd the liver removed. The mount of liver contining MBq (1-1.5 mci) of 99mTc-SC ws mied into 1 g ground beef nd the resulting 'hmburger' cooked on griller. The totl clorie content of the solid mel (25 g protein, 21 g ft) ws pproimtely 27 kcl (1.13 Mj). The liquid mrker ws MBq ( mci) of li3min-dtp mied in 15 ml of either wter, 1% detrose, or 25% detrose. The whole body rdition dose ws clculted to be pproimtely 4 microsieverts (4 mrd) for ech study. SUBJECTS/GROUPS ll subjects were non-smokers, on no mediction nd hd no gstrointestinl disese. Informed consent ws obtined nd the study ws pproved by the Reserch Review Committee of the Royl delide Hospitl. Group comprised 11 subjects (seven men, four women) who received solid nd wter. In group B, seven subject (five men, two women) were given solid nd 1% detrose, nd in group C, si subjects (five men, one womn) received solid nd 25% detrose. The men ge in ech group ws similr: group, 32 yers (rnge yers); group B, 31 yers (27-39 yers); group C, 3 yers (27-37 yers). ll subjects were within 2% of their idel weight (men ± SEM - 72±3 kg, 7±6 kg, 73±5 kg, respectively). The study ws repeted within seven dys in nine of group, five of group B, nd five of group C subjects to ssess reproducibility. Collins, Horowitz, Cook, Hrding, nd Shermn PERFORMNCE OF TEST The gstric emptying test ws begun t 12.3 hours. Ech subject hd previously eten light stndrd brekfst t 7.3 hours. The study ws performed in the sitting position with the detector behind the ptient. cross-shped mrker contining 99mTc ws tped to the subject's bck to id in correction for ptient movement during the study. The subject te the solid mel grdully over five minute period nd then drnk the 15 ml of liquid contining ll3min-dtp. Dt collection commenced t the beginning of food ingestion. t 3 minute intervls, dt cquisition ws interrupted for five minutes to llow the subject to stnd or sit wy from the cmer. Ech study ws continued for t lest two hours. DT CQUISITION scintilltion cmer (4 kev prllel-hole collimtor) interfced to computer ws used for dt collection. The energy window lternted regulrly between tht of 13mIn (393 kev) nd 99mTc (14 kev), using n utomtic switching device. During the first 1 postcibl minutes, the energy window lternted every five seconds. Subsequently, this intervl ws incresed to 5 seconds. The switching device plced switching 'mrks' in the dt strem to llow subsequent reconstruction into frme mode imges. t the end of dt cquisition, 3.7 MBq (1 uci) of 99mTc-DTP in 15 ml wter ws given orlly nd one minute left lterl imge of the upper bdomen ws tken. DT NLYSIS Frme mode reconstruction The study comprised five list mode files. Ech of these files ws reformted to produce seprte dynmic studies for the solid nd liquid components. The dynmic studies were corrected for subject movement nd religned to single reference point, using the 99mTc mrker. This fcilitted determintion of the region of interest. The solid study ws corrected for 1 3mIn Compton sctter by subtrcting proportion of the l13min imge from its corresponding 99mTc imge. Becuse the solid nd liquid studies were stored lterntively, n imge equl to the verge of the two 1i3mIn imges djcent in time to the 99mTc imge ws used for this correction. ttenution correction fctors Using the lterl imge, the distnce from the midpoint of the stomch to the collimtor surfce in cm (Xi) ws clculted t ll levels from the fundus to the pylorus (Fig. l). Two sets of line correction fctors (Ft) for the solid nd liquid phses of the Gut: first published s /gut on 1 December Downloded from on 15 Jnury 219 by guest. Protected by copyright.

3 Gstric emptying in norml subjects Lterol Posterior Xn - Fn C1F1 Cn FeuXi Totl stomoch C =C Xn-~Counts Cn i=l () Fig. 1 Correction for tissue ttenution using lterl imge of the stomch. () Genertion of correction fctors Fi = eponentil (,X,) where Xi is distnce from mid-point ofstomch to collimtor surfce nd,u is ttenution coefficient. (b) Formtion of the totl stomch counts n CT = CiF, i=l where Cj is sum, nd F, ttenution correction fctor for line i. study were generted (F, = ep (,uxi)) using the pproprite ttenution coefficient g. Histogrm genertion Using the computer disply, region of interest ws drwn to include the whole stomch, but ecluding the smll intestine. For ech frme of the study, the totl counts in the region of interest (CT) ws the sum of the individul line sums which hd been corrected for tissue ttenution (CiF,) - tht is, CT = n XC,Fi i=l (Fig. lb). The histogrms for the solid nd liquid components of the mel (epressed s percentge of the totl mel remining within the stomch vs time) were corrected for rdionuclide decy nd printed. The vlue for 1% retention of the mel ws derived from the mimum count rte chieved in the first 2 minutes of the study. Severl prmeters were derived from these histogrms. For the solid component these prmeters were: the lg period before onset of emptying, the time for 5% emptying (T5) nd the verge rte of liner emptying (epressed s %/minute). For the liquid component, the T5() nd the mount of trcer remining t 1 minutes fter ingestion were obtined. The liner emptying rte of solid ws clculted from stright line of best fit, drwn through the dt points which followed the lg period. (b) STTISTICL METHODS Dt were nlysed using Student's t test nd liner regression nlysis. The reproducibility of the technique ws nlysed using nlysis of vrince. Results PHNTOM STUDIES The ttenution coefficients in tissue were,u=.12 cm-' for 99mTc (14 kev) nd,u=9 cm-' for Il3mIn (393 kev). The frction of counts in the 113mIn window tht scttered into the technetium- 99m window ws 21%. EFFECTS OF TISSUE TTENUTION Figure 2 illustrtes typicl solid retention histogrms before nd fter correction of the dt for tissue ttenution. In the intervl from eight to 16 minutes there ws fll in count rte of 2% in the uncorrected dt s food redistributed within the stomch. This fll ws entirely ttributble to rdionuclide moving wy from the collimtor surfce while remining within the stomch (Fig. 3). In the following 16 minutes, s there ws little redistribution of solid food, the count rte remined constnt. The ppliction of line correction fctors 1-8- c 6-2 4~, o o )s?o X X oo o o o X o X o o O Before correction X fter correction Post-cibol minutes o o o o 1119 Fig. 2 Gstric emptying of 9mTc-lbelled liver before (o) nd fter () correction for tissue ttentution in control subject. rrows indicte percentge remining in stomch t 8, 12, 16, nd 32 minutes. One hundred per cent retention is derivedfrom the mimum count chieved in first 2 minutes ofstudy. 99 Gut: first published s /gut on 1 December Downloded from on 15 Jnury 219 by guest. Protected by copyright.

4 112 Solid 8 min 12 min 16 min 32 min Fi. 3 Scintiphotos showing the distribution ofsolid (9mTc-liver) in stomch of control subject t 8, 12, 16, nd 32 minutes. to the dt eliminted the pprent emptying of food from the stomch. The resulting pttern showed lg period before emptying (when food moved from the fundus to the ntrum) followed by liner emptying phse. In this study T5 chnged from 49 minutes to 58 minutes (16%) s result of correction. Tissue ttenution effects were less mrked for liquids, reflecting the higher energy of ll3min (Fig. 4). Correction ltered the T5 from 19 minutes to 21 minutes (1%). In the 24 norml controls, the men percentge increse in T5 vlues fter correction ws 22% for solid nd 17% for liquid (Tble 1). SOLID EMPTYING In ll subjects solid emptied more slowly thn liquid nd ws chrcterised by lg period of vrible durtion followed by liner emptying (Fig. 5). The solid lg period ws prolonged by the presence of both 1% nd 25% detrose in the liquid phse (p<.1). The T5 vlue for solid ws incresed by 25% detrose (p<-25) but not by 1% detrose. There ws no difference between the three groups in the rte of liner emptying fter the lg period (Tble 2), nd the dely of T5 with 25% detrose reflected lengthening of the lg period. LIQUID EMPTYING The emptying of liquid ws non-liner nd usully Collins, Horowitz, Cook, Hrding, nd Shermn 1- s - c 6- c 4-2- oo o o 1 X O Betore correction X tter correction oo X OX OOXXX oco o Post-cibol rminutes Fig. 4 Gstric emptying ofliquid (li3min-dtp) before () nd fter () correction for tissue ttenution in control subject. followed monoeponentil pttern with miniml observble lg period (Fig. 5). Twenty five per cent detrose delyed the T5 (p<25) while with 1% detrose this prmeter ws not significntly ltered (Tble 2). The mount of liquid remining t 1 minutes ws incresed by both 1% detrose nd 25% detrose (p<.25). There ws positive correltion between T5 for liquid nd T5 for solid in ll groups (r=.65). For the three groups the length of the lg period correlted directly with the liquid T5 (r=.75, P<*l). RTE OF DELIVERY OF CLORIES TO THE DUODENUM The totl number of clories (solid nd liquid) delivered to the duodenum t vrying time intervls in the first 5 minutes of the emptying study re shown in Tble 3. In both the solid nd 1% Tble 1 Effect ofttenution correction on solid nd liquid T5 Difference Post-pre X 1% post Solid (S9mTc) = 22 (7-65) Liquid (li3min) = 17 (-59) oooooxx X X o Vlues indicte men vlues nd rnge of 24 control subjects. Gut: first published s /gut on 1 December Downloded from on 15 Jnury 219 by guest. Protected by copyright.

5 Gstric emizptying in norml subjects Fig. 5 Effect ofincresing liquid clorie content on liquid () nd solid (b) emptying. Liquid mel ws either wter (), 1% detrose solution (), or 25% detrose solution (E). c 6 4 ) liquid detrose group nd the solid nd 25% detrose group, pproimtely 11 kcl (462 Kj) hd left the stomch t 5 minutes. In the group of subjects who hd received solid nd wter, the rte of delivery of clories ws significntly slower (pproimtely 72 kcl (32 Kj) t 5 minutes). REPRODUCIBILITY The reproducibility dt for the prmeters solid nd liquid T5,,, solid lg period, nd solid liner rte re illustrted in Fig. 6. wide vrition between the subjects eists for these prmeters. There ws significnt correltion between dy 1 nd dy 2 (p<.1) for the first three prmeters (r=.82,.76,.78, repectively). The correltion coefficient for the solid liner rte ws of borderline significnce (r=.41, O5<p<.1). The nlysis of vrince result is illustrted in Tble 4. The dy-tody vrition (dy effect) ws not significnt (p>.5) for ny of the four prmeters: solid nd liquid To(, solid lg period, nd solid liner rte. The vrition between subjects nd groups ws significnt for ll prmeters (p<.5) ecept the solid liner rte, where the between subject Tble 2 Effect ofincresing the liquid clorie content on solid nd liquid emptving * Wter --- 1% detrose *225% detrose do 1- `C 4.L L 1 t Post-cibl minutes Men vlues SEM 1% 25% Wter detrose detrose Number of subjects Solid lg period (min) 21±2 37±6 6±9 Solid liner rte (% min- ') ±-1 1-2±-1 Solid T^, (min) 7±7 78±8 15±13 Liquid T^, 15±2 2±2 46±7 Liquid retention fter 1 min (%) 58±4 68±2 86±3 Dt re men vlues ± SEM. (b) solid 1* 8\ 6 2 1l -Lt_ Post cibl minutes vrition ws of only borderline significnce (5<p<l1). This vribility of the dt implies tht three pired studies would be needed to detect difference in gstric emptying time (solid Tst() of 3%, five for difference of 2%, nd 19 for difference of 1% (p=.5). Discussion Previous workers hve corrected for tissue ttenution in gstric emptying studies by using the geometric men of counts tken t regulr intervls in the nterior nd posterior projections.9 It) Tothill et ll scnned the ptient t regulr intervls (1, 3, 6, 9, 12 minutes) with dul detector scnner, while Christin et 19 imged t 3 minute intervls with single scintilltion cmer. The effectiveness of the scintilltion cmer in mpping distribution chnges within the stomch, however, is reduced if dt re smpled infrequently. Our studies indicte tht dequte ttenution correction fctors my be derived from lterl imge of the stomch. The use of these correction fctors enbles continuous monitoring of both solid Tble 3 Effect of incresing the liquid clorie content on the rte of delivery of clories (solid nd liquid) to the duodenum Time fter Totl clories* (Kcl) t delivered mel completion (min) Wter 1% detrose 25% detrose * Men vlues. t 1Kcl = 4-2 K) Gut: first published s /gut on 1 December Downloded from on 15 Jnury 219 by guest. Protected by copyright.

6 1122 Collins, Horowitz, Cook, Hrding, nd Shermn 2- Solid emptying log period (minutes) Solid emptying liner emptying rte (percent per minute) 1 7- Wter 12- o 1% detrose * 25% detrose 1 5- C Wter o 1% detrose * 25% detrose o / o Dy 2 4 () 8 m * * * * * * > Dy 2 / 1 L (b) Solid emptying time for 5% emptying (minutes) Liquid emptying time for 5% emptying (minutes) cl m Wter 1% detrose 25% detrose Dy 2. >. 8 6 (c) Wter o 1% detrose * 25% detrose c 4 Dy 2 Fig. 6 (-d) Reproducibility ofgstric emptying in norml subjects. Dt were obtined on two seprte dys nd re plotted round line of identity (dy I = dy 2). The prmeters illustrted re () solid lg period; (b) solid liner rte; (c) solid T5; (d) liquid T5.. ạ. (d) 6 8 Gut: first published s /gut on 1 December Downloded from on 15 Jnury 219 by guest. Protected by copyright.

7 Gstric emptying in norml subjects Tble 4 ssessment of reproducibility using nlysis of vrince Effect Dy Subject Group Solid lg period (min) NS p<5 p<.1 Solid Tso (min) NS p<-1 p<-1 Solid liner rte (% min') NS NS NS Liquid Tso (min) NS p<5 p<-1 NS = not significnt (p>-5). nd liquid emptying using single scintilltion detector. n ccurte estimte of the time of initil emptying of food nd of the shpe of the emptying curve cn usully be obtined from the corrected dt. In pproimtely 2% of ptients, however, the shpe of the stomch results in movement of food perpendiculr to the detector nd the correction is less effective. This usully occurred in the proiml stomch, resulting in fll in count rte in the corrected dt in the erly prt of the study of solid emptying, even though there ws no evidence of food leving the stomch (determined by visul inspection of the imges). We hve ttempted to minimise this error by ignoring smll chnges in count rte in the first 15 minutes nd tking the vlue fter tht time s the 1% retention vlue. Significnt error in the mesurement of gstric emptying rte without ttenution correction cn be inferred from the pre- nd postcorrection T5 vlues obtined for solids nd liquids (Tble 1). The difference between pre- nd postcorrection vlues re similr to those reported by Tothill et l1 using the rectiliner scnner. Despite this, some groups hve mde no ttempt to correct for ttenution The contribution of Compton sctter to the lower energy isotope in dul trcer studies cn be minimised by using reltively lower quntities of the high energy trcer.9 In mny gstric emptying studies, however, lrger mounts of higher energy trcer re used to chieve good temporl resolution nd correction fctors must be pplied. In phntom studies, Weiner et l'3 found tht the percentge of downsctter from 1l3mIn into the 99mTc window rnged from 39% (fied region of interest) to 74%, when downsctter ws considered in the whole field of view. The ltter figure is of interest only if the percentge remining in the stomch is clculted s frction of the totl bdominl ctivity. Our phntom studies using fied region of interest did not confirm their result. Rpid time smpling in the first 1 minutes (five second store every 1 seconds) enbled our correction to be tested in ptient 1123 studiesq nd no significnt chnge ws observed in the solid count rte s liquid entered the stomch. Becuse of the fster emptying of the liquid component (high energy nuclide) from the stomch, this correction is minly required during the lg period of the solid study. In the norml stomch, emptying of solid food is preceded by ntrl propulsive nd retropulsive mincing, the end point being the pssge into the duodenum of smll prticles <1 mm in size.4 We found tht solid emptied in liner pttern fter n initil lg period in ccordnce with the findings of other uthors The lg period before food enters the duodenum reflects both redistribution of food from fundus to ntrum nd the time tken to reduce some solid food to smll prticles. It is therefore dependent on fundl tone, stomch volume, nd ntrl motility. Liner emptying probbly occurs becuse of the bility of the ntrum to mintin reltively constnt volume during emptying.8 14 The min fctor controlling the emptying of liquids is the pressure grdient cross the gstroduodenl junction which is lrgely dependent on fundl tone Our observtion tht liquid emptying is n eponentil or volume-dependent process hs been reported by other investigtors nd is consistent with this postulte. In mied solid-liquid mels, liquids hve been observed to empty more rpidly thn solid, nd correltion between the rtes of solid nd liquid emptying hs previously been noted.3 14 The rte of gstric emptying for both solids nd liquids is lso determined in prt by the composition of the duodenl content. Previous investigtors, using non-isotopic mels, hve shown tht gstric emptying slows with incresing clorie content of liquid mel, nd tht this dely is medited by duodenl receptors In primtes19 nd in humns,2 solutions of crbohydrte, protein, nd ft slow gstric emptying in direct proportion to their clorie concentrtion in the rnge.2-1 kcl/ ml ( Kj/ml), so tht the rte of delivery of energy to the duodenum is mintined t constnt level. The slowing of gstric emptying my be medited by the osmotic effects17-19 or ltertions in clcium binding21 produced in the duodenum by the digestion products of food. In this study, the progressive increse in clorie content of the liquid mel from to -4 to 1 kcl/ml ( to 1.7 to 4.2 Kj/ml) resulted in dely in both solid nd liquid emptying. For liquids, generlised slowing of the entire emptying curve ws evident, while the dely in solid emptying reflected lengthening of the lg period, with no ltertion in the rte of liner emptying. Gut: first published s /gut on 1 December Downloded from on 15 Jnury 219 by guest. Protected by copyright.

8 1124 Collins, Horowitz, Cook, Hrding, nd Shermn The dely in liquid emptying with incresing clorie content of the liquid mel is consistent with n inhibitory effect medited by duodenl receptors. s incresing the liquid clorie lso delyed the redistribution of solid food from fundus to ntrum (without ltering the rte of liner emptying), it is likely tht the dely of both solid nd liquid emptying reflects reduction in fundl tone medited by duodenl receptors. The direct reltionship between the liquid T5 nd the durtion of the lg period supports this hypothesis. In this study of mied solid nd liquid mel, the rte of delivery of clories to the duodenum ws pproimtely 2.2 kcl/min (9.2 Kj/min) in the two groups when liquid clories were given with the solid food. This result is similr to tht previously obtined with liquid mels.2 In the group of ptients who received wter, clories entered the duodenum only fter the solid lg period, prtly ccounting for the slower initil delivery of clories in this group. There hve been no published reproducibility studies using 113mIn-DTP nd 99MTc-SC to mesure gstric emptying. Previous reproducibility studies using other rdionuclides in norml subjects hve shown dy-to-dy vrition in gstric emptying rtes within norml subjects, s well s wide vritions in rtes between subjects In this study, the dy-to-dy vrition in gstric emptying within individul subjects ws not significnt compred with the vrition between subjects in ech group nd did not ffect the sensitivity of the technique in its bility to discriminte between the three groups studied. Dr M Horowitz ws supported by grnt from the Ntionl Helth nd Medicl Reserch Council of ustrli. We wish to thnk Dr B W Gbb for his ssistnce with the sttisticl nlysis. References 1 Chndhuri TK. Use of 99mTc-DTP for mesuring gstric emptying time. J Nucl Med 1974; 15: Heding RC, Tothill P, Lidlw J, Shermn DJC. n evlution of 113mIn DTP chelte in the mesurement of gstric emptying by scintiscnning. Gut 1971; 12: Heding RC, Tothill P, McLoughlin GP, Shermn DJC. Gstric emptying rte mesurement in mn. double isotope scnning technique for simultneous study of liquid nd solid components of mel. Gstroenterology 1976; 71: Meyer JH, McGregor IL, Gueller R, Mrtin P, Cvlieri R. 99mTc-tgged chicken liver s mrker of solid food in the humn stomch. m J Dig Dis 1976; 21: Horowitz M, Collins P, Cook DJ, Hrding P, Shermn DJC. The effect of vrition of the concentrtion of detrose on the emptying of mied liquid nd solid mel. [bstrct.] Gstroenterology 1982; 82: Horowitz M, Cook DJ, Collins PJ, Hrding PE, Hooper MJ, Wlsh JF, Shermn DJC. Mesurement of gstric emptying fter gstric bypss surgery using rdionuclides. Br J Surg 1982; 69: Horowitz M, Cook DJ, Collins PJ, Hrding PE, Shermn DJC. The ppliction of techniques using rdionuclides to the study of gstric emptying. Surg Gynecol Obstet 1982; 155: Sheiner HJ, Quinln MF, Thompson IJ. Gstric motility nd emptying in norml nd post-vgotomy subjects. Gut 198; 21: Christin PE, Moore JG, Sorenson J, Colemn RE, Weich DM. Effects of mel size nd correction technique on gstric emptying time: studies with two trcers nd opposed detectors. J Nucl Med 198; 21: Tothill P, McLoughlin GP, Heding RC. Techniques nd errors in scintigrphic mesurements of gstric emptying. J Nucl Med 1978; 19: McGregor IL, Mrtin P, Meyer JH. Gstric emptying of solid food in norml mn nd fter subtotl gstrectomy nd truncl vgotomy with pyloroplsty. Gstroenterology 1977; 72: Lvigne ME, Wiley ZD, Meyer JH, Mrtin P, McGregor IL. Gstric emptying rtes of solid food in reltion to body size. Gstroenterology 1978; 74: Weiner K, Grhm LS, Reedy T, Elshoff J, Meyer JH. Simultneous gstric emptying of two solid foods. Gstroenterology 1981; 81: Moore JG, Christin PE, Colemn RE. Gstric emptying of vrying mel weight nd composition in mn. Evlution by dul liquid- nd solid-phse isotopic method. Dig Dis Sci 1981; 26: Wilbur BG, Kelly K. Effect of proiml gstric, complete gstric nd truncl vgotomy on cnine gstric electricl ctivity, motility nd emptying. nn Surg 1973; 178: Kelly K. Gstric emptying of liquids nd solids: roles of proiml nd distl stomch. m J Physiol 198; 239: G Hunt JN, Stubbs DF. The volume nd energy content of mels s determinnts of gstric emptying. J Physiol 1975; 245: Hunt JN, Csh R, Newlnd P. Energy density of food, gstric emptying nd obesity. m J Clin Nutr 1978; 31: S McHugh PR, Morn TH. Clories nd gstric emptying: regultory cpcity with implictions for feeding. m J Physiol 1979; 236: R Gut: first published s /gut on 1 December Downloded from on 15 Jnury 219 by guest. Protected by copyright.

9 Gstric emptying in norml subjects Brener W, Hendri TR, McHugh PR. Intrduodenl glucose clories control gstric emptying in mn. [bstrct.] Gstroenterology 1981; 8: Hunt JN. McHugh PR. Does clcium medite the slowing of gstric emptying in primtes? m J Physiol 1982; 243: G Clderon M, Sonnemker RE, Hersh T, Burdine J. 99mTc-humn lbumin microspheres (HM) for mesuring the rte of gstric emptying. Rdiology 1971; 11: Gut: first published s /gut on 1 December Downloded from on 15 Jnury 219 by guest. Protected by copyright.