Reproducibility of a solid and of a liquid caloric meal for gastric emptying studies

Simple meals are required for routine scintigraphic gastric emptying studies. We evaluated the reproducibility of a caloric liquid meal (520 kcal) compared to that of a solid meal (638 kcal) in 8 and 11 healthy volunteers, respectively. Gastric emptying rates and half-times were similar in two tests using the same meal, while the methods used to express lag times were not highly reproducible. The emptying rates and half-times of the liquid meal were delayed after the intake of bellafoline. In conclusion, this study demonstrates that: (a) gastric emptying rates and half-times are reproducible parameters for the expression of scintigraphic gastric emptying studies; (b) mathematical methods to express lag times are not highly reproducible; (c) a 500 kcal liquid meal is sensitive to the effects of bellafoline, a drug able to delay gastric emptying. Further clinical evaluation is required to test its applicability in routine studies.     

Effect of mild mental stress on solid phase gastric emptying in healthy subjects

Radionuclide gastric emptying studies are performed in clinical routine but the possible influence of the mental state of the patient is never taken into account. We wanted to evaluate the effect of a mild psychological stress on solid phase gastric emptying in healthy young male volunteers. The standard meal consisted of a pancake (500 kJ) without additional liquid. Simultaneous dynamic acquisitions of gastric activity in anterior and posterior projection were taken during 90 min starting from the onset of the meal. Gastric emptying was evaluated three times in basal conditions and once under mental stress. Stress was induced by means of a dichotomous listening test, lasting for 30 min, starting at the end of the meal. The results of rest and stress studies were compared. Mild mental stress has a significant influence on gastric emptying. The lag phase increased from 11 +/- 3 min to 36 +/- 10 min (mean +/- S.D.) (p less than 0.005) and the gastric emptying rate from 79 +/- 13%/hour to 100 +/- 31%/hour (mean +/- S.D.) (not significant). During a stress period gastric emptying as a whole is delayed but this is mainly due to the prolongation of the lag phase. Our data also suggest that during the stress period gastric emptying is interrupted and reactivated once the stress period has ended.     

~(13)C-辛酸呼吸试验测定糖尿病胃固体排空功能的重复性研究

目的　观察13 C 辛酸呼吸试验测定糖尿病患者胃固体排空时间及其变异性 ,以及心自主神经病变和病理性胃排空状况对其的影响。方法　 9例对照者和 15例糖尿病患者 [平均糖基化血红蛋白 (HbA1c) 7 8% ]1周内行 2次13 C 辛酸呼吸试验 ,采用非线性回归法计算半排空时间 (t1/ 2 )和缓慢期时间 (tlag) ,同时采用心自主神经功能试验判断有无心自主神经病变。结果　对照组t1/ 2 批内CV为 11 7%、tlag批内CV为 19 4% ,糖尿病患者t1/ 2 批内CV为 17 8%、tlag批内CV为 2 8 2 % ,对照者和糖尿病患者间差异无显著性。t1/ 2 和tlag的批内CV在糖尿病患者伴有和无心自主神经病变之间以及在正常胃排空时间和延迟性胃排空时间之间差异无显著性。结论　13 C 辛酸呼吸试验测定胃固体排空功能有较高的重复性 ,并不受心自主神经病变和病理性胃排空的影响。     

Gastric emptying after partial gastrectomy without vagotomy with primary Roux-en-Y or Billroth II anastomosis

Several clinical studies have indicated that gastric emptying is delayed in patients with Roux-en-Y biliary diversion with vagotomy. In order to determine whether Roux-en-Y diversion without vagotomy also induces delayed gastric emptying, we have compared the effect of gastrectomy without vagotomy with either Billroth II or Roux-en-Y anastomosis on gastric emptying of a liquid and solid meal in 22 peptic ulcer patients. The emptying half-times (t1/2) for solid food were not significantly different, 54; 24-122 min (median and range) in the 11 patients with Billroth II gastrectomy, 68; 44-189 min in the 11 patients with Roux-en-Y gastrectomy, and 83; 27-114 min in 11 normal control subjects. However, the lag phase was significantly (p less than 0.01) shorter in the patients with Billroth II gastrectomy (5; 0-43 min) and Roux-en-Y gastrectomy (4; 2-12 min) than in the control subjects (10; 4-22 min). The t1/2's for the fluid meal were similar, 7; 4-49 min after Billroth II gastrectomy, 8; 4-32 min after Roux-en-Y gastrectomy, and 9; 3-20 min in the control subjects. In all subjects the lag phase for the fluid meal was very short, ranging from 0 to 3 min. It is concluded that Roux-en-Y diversion per se does not delay gastric emptying in man.     

The effect of trimebutine maleate on gastric emptying in patients with non-ulcer dyspepsia

The study was designed to investigate the effect of trimebutine maleate, a drug used in both hyperkinetic and hypokinetic motility disorders, on gastric emptying in patients with non-ulcer dyspepsia having prolonged gastric emptying rates and to compare the parameters used for the determination of the lag period observed during the emptying of solid foods from the stomach. Gastric emptying was measured by the radionuclide technique. Twenty normal volunteers and 43 patients with non-ulcer dyspepsia participated in the study. Radionuclide imaging was performed by using a solid meal labeled with 99mTc-tin colloid. Of the patients with non-ulcer dyspepsia, 20 had prolonged gastric emptying. They were given three weeks of oral treatment with trimebutine maleate and had their radionuclide gastric emptying study repeated. Treatment with trimebutine maleate resulted in reduction in duration of the lag period and less retention of food at 100 minutes (p < 0.0005). After treatment with trimebutine maleate, no significant difference has been observed in the mean symptom score of patients with prolonged gastric emptying. Among the parameters used for the determination of the lag period, lag period determined by a mathematical equation (TLAG) has been found to be longer than the lag period determined by visual inspection of the images (VLAG) and there was correlation between the two parameters when the lag time was short.     

Scintigraphic quantitation of gastrointestinal motor activity and transport: oesophagus and stomach

For the recognition and characterisation of oesophageal motor disorders, manometry represents the most reliable tool but yields no information on bolus transport. The transport can be quantitated by radionuclide techniques. The patient is positioned supine beneath a gamma-camera and instructed to swallow a radiolabelled bolus in a single gulp. Using a marker over the cricoid and the activity in the stomach as landmarks, regions of interest are drawn representing the upper, middle and lower third of the oesophagus and the gastric fundus. Activity-time curves enable one to recognise the clearance patterns in these regions. In combination, manometric and radionuclide transit studies recognise a higher number of motor disorders than either procedure alone. Radionuclide methods also are the most reliable and sensitive to quantitate gastric emptying. Procedure, meal size and composition as well as patient position must be standardised and correction techniques applied. The emptying of solid and liquid meal constituents can be evaluated concomitantly. Solids start to empty only after a lag phase of varying extent. With semi-solid meals, which are emptied at the same rate as solid meals of identical composition in the postlag phase, the recording time can be considerably shorter. Besides gastric emptying, the amplitude, frequency and propagation velocity of antral contractions can be recorded using serial images of short frame time and specially devised analytic techniques. Offprint requests to: G. Stacher     

Scintigraphic quantitation of gastrointestinal motor activity and transport: oesophagus and stomach.

For the recognition and characterisation of oesophageal motor disorders, manometry represents the most reliable tool but yields no information on bolus transport. The transport can be quantitated by radionuclide techniques. The patient is positioned supine beneath a gamma-camera and instructed to swallow a radiolabelled bolus in a single gulp. Using a marker over the cricoid and the activity in the stomach as landmarks, regions of interest are drawn representing the upper, middle and lower third of the oesophagus and the gastric fundus. Activity-time curves enable one to recognise the clearance patterns in these regions. In combination, manometric and radionuclide transit studies recognise a higher number of motor disorders than either procedure alone. Radionuclide methods also are the most reliable and sensitive to quantitate gastric emptying. Procedure, meal size and composition as well as patient position must be standardised and correction techniques applied. The emptying of solid and liquid meal constituents can be evaluated concomitantly. Solids start to empty only after a lag phase of varying extent. With semi-solid meals, which are emptied at the same rate as solid meals of identical composition in the postlag phase, the recording time can be considerably shorter. Besides gastric emptying, the amplitude, frequency and propagation velocity of antral contractions can be recorded using serial images of short frame time and specially devised analytic techniques.     

Nationwide standardisation and evaluation of scintigraphic gastric emptying: reference values and comparisons between subgroups in a multicentre trial

By means of a standardised procedure, reference values for scintigraphic gastric emptying were established. The influence of gender, age, menstrual cycle, body mass index (BMI) and smoking habits was also evaluated. Eight centres recruited 20 healthy subjects each. The meal consisted of a technetium-99m labelled omelet (1300 kJ) and of 150 ml unlabelled soft drink. Geometric means of frontal and dorsal acquisitions were utilised in a linear fit model for determination of the linear emptying rate, and by using the intercepts of the regression line with the 90% and 50% levels, the lag phase and half-emptying time, respectively, were defined. All individuals showed an initial lag phase and subsequent linear emptying. Because of a longer lag phase and a slower linear emptying rate, premenopausal women had a slower gastric emptying than postmenopausal women and men of all ages. The gastric emptying rate increased with age in the women, mainly due to a shortened lag phase, while the emptying rate remained almost unchanged with age in the males. There were no significant differences in results between the centres. The menstrual cycle, BMI and smoking habits did not affect emptying. In conclusion, the fact that the results showed a slower gastric emptying rate in younger women compared with older women and men indicates that it is necessary to use separate reference values for fertile females. Received 30 December 1999 and in revised form 29 February 2000     

Nationwide standardisation and evaluation of scintigraphic gastric emptying: reference values and comparisons between subgroups in a multicentre trial

By means of a standardised procedure, reference values for scintigraphic gastric emptying were established. The influence of gender, age, menstrual cycle, body mass index (BMI) and smoking habits was also evaluated. Eight centres recruited 20 healthy subjects each. The meal consisted of a technetium-99m labelled omelet (1,300 kJ) and of 150 ml unlabelled soft drink. Geometric means of frontal and dorsal acquisitions were utilised in a linear fit model for determination of the linear emptying rate, and by using the intercepts of the regression line with the 90% and 50% levels, the lag phase and half-emptying time, respectively, were defined. All individuals showed an initial lag phase and subsequent linear emptying. Because of a longer lag phase and a slower linear emptying rate, premenopausal women had a slower gastric emptying than postmenopausal women and men of all ages. The gastric emptying rate increased with age in the women, mainly due to a shortened lag phase, while the emptying rate remained almost unchanged with age in the males. There were no significant differences in results between the centres. The menstrual cycle, BMI and smoking habits did not affect emptying. In conclusion, the fact that the results showed a slower gastric emptying rate in younger women compared with older women and men indicates that it is necessary to use separate reference values for fertile females.     

Comparison of total and compartmental gastric emptying and antral motility between healthy men and women

There is increasing evidence of gender-related differences in gastric emptying. The purpose of this study was first, to confirm the difference in gastric emptying for both solid and liquid test meals between healthy men and women, and secondly, to investigate the origin of this difference by studying regional gastric emptying and antral motility. A standard gastric emptying test with additional compartmental (proximal and distal) evaluation and dynamic imaging of the antrum was performed in 20 healthy women studied during the first 10 days of the menstrual cycle, and in 31 healthy age-matched men. In concordance with previous reports, women had a longer half-emptying time for solids as compared to men (86.2±5.1 vs 52.2±2.9 min, P<0.05). In our observations this seemed to be related to a significantly prolonged lag phase and a significant decrease in terminal slope. Dynamical antral scintigraphy did not show a significant difference. The distribution of the test meal within the stomach (proximal vs distal) showed more early proximal retention in women as compared to men. The terminal slope of the distal somach was significantly lower in women. We did not observe a significant difference in gastric emptying of the liquid test meal between men and women. Gastric emptying of solids is significantly slower in healthy women as compared to men. These findings emphasise the importance of using different normal values for clinical and research purposes in gastric emptying scintigraphy in men and women. The difference could not be explained by antral motility alone. Increased proximal retention and a lower terminal emptying rate in women are observations to be further investigated. Received 2 February and in revised form 17 April 1998     

Comparison of left anterior oblique and geometric mean gastric emptying

A left anterior oblique image (LAO) and the geometric mean of anterior and posterior counts have both been proposed as methods for acquiring gastric emptying data. Both approaches are used to correct for the changes in attenuation that occur as the depth of radiolabeled solids changes during gastric emptying. These two methods were compared by using a power exponential curve fit to calculate a lag phase, an equilibrium emptying rate, and a half-time for gastric emptying in 20 patients. There were no significant differences (mean +/- 1 s.e.m.) in the measured half-emptying time (115 +/- 10 versus 104 +/- 7 min) (p = 0.08) or rate of gastric emptying (0.015 +/- 0.002 versus 0.015 +/- 0.002 min-1) (p = 0.56) for LAO imaging versus the geometric mean. However, the LAO measurements of the lag phase were significantly higher (69 +/- 7 min) than the geometric mean (53 +/- 6 min) measurements (p = 0.004). This resulted in 4/20 (20%) of patients with normal geometric mean lag phase measurements who would have been reclassified as abnormal using the LAO method.     

Proximal, distal and total stomach emptying of a digestible solid meal in normal subjects

The gastric fundus and antrum probably play different roles in the emptying of solids and liquids in man, but there is little information about the intragastric distribution of food. We have used a new radionuclide technique to quantify proximal, distal and total stomach emptying of a digestible solid meal (100 g of 99Tcm-labelled liver/ground beef given with 150 ml of 10% dextrose) in 13 normal subjects. A proximal reservoir area was seen after consumption of the meal, and used to define the proximal stomach region. A line drawn immediately below this area divided the total stomach region into proximal and distal stomach. Emptying from the total stomach exhibited two phases--an initial lag period (median 41 min, range 21-57 min), followed by approximately linear emptying. Redistribution of food from the proximal to the distal stomach was a major component of the lag period in 11 of the 13 subjects. In the remaining two subjects, redistribution was rapid (proximal 50% emptying time of 4 and 10 min) and antral retention was the major component of the lag period. In seven subjects, a region of reduced activity (contraction band) was seen. The midpoint of this band closely approximated to the line used to divide proximal and distal stomach. We suggest that a contraction band may be responsible for the proximal gastric reservoir seen after meal consumption and plays an important role in the redistribution and emptying of digestible solid food from the stomach. There is considerable variation between normal subjects in the rate of transfer of digestible solid food from the proximal to the distal stomach.     

非溃疡性消化不良飞行员胃运动功能的改变

目的　对患有非溃疡性消化不良的飞行人员进行胃排空功能检测。　方法　采用双核素标记试餐及单光子发射计算机体层摄影 (SPECT)技术 ,对 5 4例非溃疡性消化不良 (NUD)飞行员(其中包括类溃疡型 2 3例 ,运动障碍型 2 6例 ,返流型 5例 )和 6 4例健康飞行员进行胃排空测定 ,求出各自全胃半排空时间 (T1 /2 ) ,近端胃半排空时间 (PT1 /2 ) ,固体食物开始排空前的延迟时间 (T1 )及其异常的发生率。　结果　与对照组相比 ,NU D组飞行员液体 T1 /2 延长 ,与 3型 NU D间均无明显关系 ;固体 T1 /2 明显延长 ,异常发生率 72 .2 % ,与运动障碍型 NUD和返流型 NU D呈正相关 (r=0 .81和 0 .78,P<0 .0 5 ) ;PT1 /2 与类溃疡型 NUD呈正相关 (r=0 .75 ,P<0 .0 5 ) ;T1 异常发生率 88.9% ,其中38.2 %延迟 ,与运动障碍型 NU D呈正相关 (r=0 .78,P<0 .0 5 ) ,另 6 1.8% T1 消失 ,与类溃疡型 NU D呈负相关 (r=- 0 .6 7,P<0 .0 5 )。　结论　 NUD飞行员多有固体食物排空障碍。     

Use of Technegas as a radiopharmaceutical for the measurement of gastric emptying.

Many radiopharmaceuticals and test meals that are used to measure gastric emptying are less than optimal. A vegetable-based solid meal, such as rice, labelled with a radiopharmaceutical that also has the capacity to measure gastric emptying of liquids, is likely to be ideal. The role of Technegas as a radioisotopic marker to measure gastric emptying of rice and liquids was evaluated. Technegas-labelled rice was incubated in 0.9% saline, 1 M HCl and simulated gastric fluid (3.2 g/l pepsinogen, pH 2-3) to assess stability of the label. In eight healthy volunteers gastric emptying of two meals - 200 g rice (370 kcal) and 75 g dextrose dissolved in 300 ml water (300 kcal), both labelled with 20 MBq of Technegas - was measured scintigraphically. Over 4 h, the average label stability was 93.7%+/-0.5% in 0.9% saline, 91.0%+/-0.4% in 1 M HCl and 93.6%+/-0.7% in simulated gastric juice. The lag phase was longer for rice than dextrose (25+/-7 min vs 4+/-2 min; P<0.05), but there was no difference in the post-lag emptying rate (2.1+/-0.3 kcal/min vs 1.7+/-0.2 kcal/min; P=0.2) between the two meals. We conclude that Technegas is a suitable radiopharmaceutical for measurement of gastric emptying of rice and nutrient-containing liquids.     

Continuous anterior acquisitions in gastric emptying: comparison with the mean

Depth correction is necessary when gastric emptying is studied by means of a labeled meal. In this study continuous anterior images were acquired from the onset of the food ingestion. Differences in depth were measured using a left lateral view. A minimal and crude depth correction was performed. The results obtained with this correction method were compared with those obtained using the depth correction technique of the mean. The results obtained in the anterior projection without any depth correction were also compared with those obtained using the method of the mean. The results obtained with both correction techniques were identical in 18 gastric emptying studies. This approach also permits the creation of a time-activity curve over the duodenum in the anterior projection. In this way the lag phase can easily be assessed.     

Use of Technegas as a radiopharmaceutical for the measurement of gastric emptying

Many radiopharmaceuticals and test meals that are used to measure gastric emptying are less than optimal. A vegetable-based solid meal, such as rice, labelled with a radiopharmaceutical that also has the capacity to measure gastric emptying of liquids, is likely to be ideal. The role of Technegas as a radioisotopic marker to measure gastric emptying of rice and liquids was evaluated. Technegas-labelled rice was incubated in 0.9% saline, 1 M HCl and simulated gastric fluid (3.2 g/l pepsinogen, pH 2–3) to assess stability of the label. In eight healthy volunteers gastric emptying of two meals – 200 g rice (370 kcal) and 75 g dextrose dissolved in 300 ml water (300 kcal), both labelled with 20 MBq of Technegas – was measured scintigraphically. Over 4 h, the average label stability was 93.7%±0.5% in 0.9% saline, 91.0%±0.4% in 1 M HCl and 93.6%±0.7% in simulated gastric juice. The lag phase was longer for rice than dextrose (25±7 min vs 4±2 min; P<0.05), but there was no difference in the post-lag emptying rate (2.1±0.3 kcal/min vs 1.7±0.2 kcal/min; P=0.2) between the two meals. We conclude that Technegas is a suitable radiopharmaceutical for measurement of gastric emptying of rice and nutrient-containing liquids. Received 8 March and in revised form 19 April 1999     

The two-component stomach: effects of meal particle size on fundal and antral emptying

Using a dual-headed gamma camera and a standardized egg test meal labeled with 99mTc-sulfur colloid, the quantitative emptying of the total, proximal and distal stomach in five normal subjects was characterized. The same egg meal was given to the volunteers in 3 different forms: homogenized, and as 2.5 mm and 5.0 mm cubes on 3 separate occasions for a total of 15 studies. For the total stomach emptying, the lag phase and half emptying time (T1/2) obtained using a power exponential model were significantly shorter for the homogenized test meal than for the 2.5 mm and 5.0 mm cubed egg particles; the lag phases were 29 +/- 19 min (mean +/- SD) vs 55 +/- 26 (P less than 0.05) and 64 +/- 24 min (P less than 0.01), the T1/2's were 71 +/- 30 min vs 91 +/- 26 (P less than 0.05) and 104 +/- 30 min (P less than 0.05), respectively. For the proximal stomach, no statistically significant difference was observed among the 3 test meals; the T1/2s for the homogenized, 2.5 mm and 5.0 mm cubed meals were 65 +/- 26 min, 53 +/- 18 min and 64 +/- 20 min, respectively. For the distal stomach, both the peak activity (%) and time to peak activity (min) were significantly higher for the 2.5 mm cubes (43%, 54 min) and the 5.0 mm cubes (38%, 60 min) than for the homogenized eggs (16.4%, 30 min) (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)     

The two-component stomach: effects of meal particle size on fundal and antral emptying

Using a dual-headed gamma camera and a standardized egg test meal labeled with ^99mTc-sulfur colloid, the quantitative emptying of the total, proximal and distal stomach in five normal subjects was characterized. The same egg meal was given to the volunteers in 3 different forms: homogenized, and as 2.5 mm and 5.0 mm cubes on 3 separate occasions for a total of 15 studies. For the total stomach emptying, the lag phase and half emptying time (T _1/2) obtained using a power exponential model were significantly shorter for the homogenized test meal than for the 2.5 mm and 5.0 mm cubed egg particles; the lag phases were 29±19 min (mean±SD) vs 55±56 (P<0.05) and 64±24 min (P<0.01), the T _1/2s were 71±30 min vs 91±26 (P<0.05) and 104±30 min (P<0.05), respectively. For the proximal stomach, no statistically significant difference was observed among the 3 test meals; the T _1/2s for the homogenized, 2.5 mm and 5.0 mm cubed meals were 65±26 min, 53±18 min and 64±20 min, respectively. For the distal stomach, both the peak activity (%) and time to peak activity (min) were significantly higher for the 2.5 mm cubes (43%, 54 min) and the 5.0 mm cubes (38%, 60 min) than for the homogenized eggs (16.4%, 30 min) (P<0.01). The correlation between the lag phase for the total stomach and the time to peak activity in the distal stomach was excellent (r=0.85, P<0.001 suggesting that the lag phase may correspond to the maximum filling of the distal stomach. These results demonstrate quantitatively that the proximal portion of the stomach is mainly responsible for the receipt and storage of food and the emptying of liquids, while the distal stomach appears to be primarily involved with the processing of solid food before its passage through the pylorus.     

Effect of proximal vagotomy and Roux-en-Y diversion on gastric emptying kinetics in asymptomatic patients

The role of the distal stomach in gastric emptying was studied. Ten patients with proximal gastric vagotomy (PV) and 10 age-matched patients with Roux-en-Y gastro-jejunostomy (R-Y) were compared with 10 healthy controls. Gastric emptying of solids and liquids was determined by the use of Tc-99m SC scrambled eggs and In-111 DTPA. In PV, gastric emptying of both solids and liquids was delayed; the prolongation with solids was mainly accounted for by an abnormal lag phase. In R-Y patients, no lag phase was observed, and the solid emptying curve pattern was characterized by early rapid emptying followed by very slow emptying. Both the solid and liquid phases were prolonged. The lag phase is affected by proximal vagotomy and is mainly determined by the distal stomach, which appears to be essential for normal emptying.     

Correction for tissue attenuation in radionuclide gastric emptying studies: a comparison of a lateral image method and a geometric mean method

Variation in depth of radionuclide within the stomach may result in a significant error in the measurement of gastric emptying if no attempt is made to correct for gamma-ray attenuation by the patient's tissues. In this study a method of attenuation correction, which uses a single posteriorly located scintillation camera and correction factors derived from a lateral image of the stomach, was compared with a two-camera geometric mean method, both in phantom studies and in five volunteer subjects. A meal of 100 g of ground beef containing 99Tcm-chicken liver, and 150 ml of water, was used in the in vivo studies. In all subjects the geometric mean data showed that solid food emptied in two phases: an initial lag period, followed by a linear emptying phase. Using the geometric mean data as a standard, the anterior camera overestimated the 50% emptying time (T50) by an average of 15% (range 5-18) and the posterior camera underestimated this parameter by 15% (4-22). The posterior data, corrected for attenuation using the lateral image method, underestimated the T50 by 2% (-7 to +7). The difference in the distances of the proximal and distal stomach from the posterior detector was large in all subjects (mean 5.7 cm, range 3.9-7.4). We conclude that attenuation effects may account for large errors in the measurement of gastric emptying with radionuclide methods and that the application of correction factors derived from a lateral image of the stomach reduces these errors.