Gastric volumetry for the assessment of fundic compliance and visceral hypersensitivity in patients with gastroparesis: a retrospective comparative study.

BACKGROUND/AIMS: The evaluation of visceral hypersensitivity and gastric accommodation in patients with gastroparesis (GP) is difficult. CT-scan gastric volumetry allows to test the distension of different regions of the stomach. We aimed to study gastric volumes and patient's sensitivity to gastric distension between in patients with GP compared to patients with GERD. METHOD: Retrospective study including patients who had CT-scan volumetry for GP or GERD. Two CT-scan series were made after gastric distension: left lateral decubitus 30° (LLD30) for antrum and right lateral decubitus (RLD) for body. Pain and discomfort were assessed using visual analogue scale (VAS). Gastric volumes were measured for LLD30 and RLD. RESULTS: 13 patients (7 GP and 6 GERD) were included. Mean age was 35.6+/-7.3 years. Median gastric volume in the RLD was lower in GP vs GERD (927+/-208 ml vs. 1115+/-163 ml; p = 0.046) while it was similar for LLD30 (1053+/-228 ml vs. 1054+/-193 ml; p = 0.603). GP patients had significantly more pain and discomfort during the procedure: pain VAS for GP was 6[0-9] versus 0[0-2] for GERD, p = 0.004, discomfort VAS for GP was 7[4-10] versus 4[0-5] for GERD, p = 0.007. 66.7% of GERD patients felt no pain vs. 14.3% in GP, p = 0.053. CONCLUSION: This pilot study suggests that GP could be associated with a reduced gastric volume compared to GERD in RLD after gaseous distension. In contrast, patient self-assessment of pain related to gastric distension was greater int GP patients. A lack of fundus accommodation and visceral hypersensitivity could explain some mechanisms in the genesis of GP symptoms.

Gastroparesis is associated with lower volumes in right lateral decubitus suggesting a lower distensibility of the fundus.Gastric volumetry is more painful in patients with gastroparesis than GERD controls, suggesting visceral hypersensitivity to mechanical distension.

Delayed Gastric Emptying and Gastric Remnant Function After Pancreaticoduodenectomy: A Systematic Review of Objective Assessment Modalities.

BACKGROUND: Delayed gastric emptying (DGE) is a frequent complication after pancreaticoduodenectomy (PD). The diagnosis of DGE is based on International Study Group for Pancreatic Surgery (ISGPS) clinical criteria and objective assessments of DGE are infrequently used. The present literature review aimed to identify objective measures of DGE following PD and determine whether these measures correlate with the clinical definition of DGE. METHODS: A systematic search was performed using the MEDLINE Ovid, EMBASE, Google Scholar and CINAHL databases for studies including pancreatic surgery, delayed gastric emptying and gastric motility until June 2022. The primary outcome was modalities undertaken for the objective measurement of DGE following PD and correlation between objective measurements and clinical diagnosis of DGE. Relevant risk of bias analysis was performed. RESULTS: The search revealed 4881 records, of which 46 studies were included in the final analysis. There were four objective modalities of DGE assessment including gastric scintigraphy (n = 28), acetaminophen/paracetamol absorption test (n = 10), fluoroscopy (n = 6) and the 13C-acetate breath test (n = 3). Protocols were inconsistent, and reported correlations between clinical and objective measures of DGE were variable; however, amongst these measures, at least one study directly or indirectly inferred a correlation, with the greatest evidence accumulated for gastric scintigraphy. CONCLUSION: Several objective modalities to assess DGE following PD have been identified and evaluated, however are infrequently used. Substantial variability exists in the literature regarding indications and interpretation of these tests, and there is a need for a real-time objective modality which correlates with ISGPS DGE definition after PD.

Preoperative bedside ultrasound assessment of gastric volume and evaluation of predisposing factors for delayed gastric emptying: a case-control observational study.

Perioperative pulmonary aspiration of gastric content is a serious complication. Fasting guidelines try to ensure an empty stomach before intervention. Certain medications or pathologies may cause delayed gastric emptying. Bedside ultrasonography is a useful tool when gastric content status is unclear or in emergency situations where fasting is not feasible. The aim of this prospective case-control observational study was to assess differences in gastric fluid volume between fasted patients with or without predisposing factors for delayed gastric emptying. Patients were preoperatively scanned. Antral cross-sectional area was measured by two tracing methods and total gastric clear fluid volumes were calculated. Data was recorded from September 2018 to March 2019 in a university hospital setting in Barcelona, Spain. Fifty-three patients were enrolled, 23 with delayed gastric emptying predisposing factors (DGEF) and 30 without non-DGEF. Ultrasound-estimated gastric clear fluid volume was 35.21 ± 32.69 mL in the DGEF versus 53.50 ± 30.72 mL in the non-DGEF group (p = 0.08). Average volume per unit of weight was 0.61 ± 0.46 mL/kg. Only 1 patient in the DGEF group had a volume that posed a higher risk of aspiration (1.57 mL/kg). Perfect correlation (R = 0.91; p < 0.01) and concordance (0.91; 95% CI 0.83; 0.95) was found between tracing methods. Minimal gastric content was observed in scheduled surgery in spite of predisposing factors for delayed gastric emptying. Ultrasound clear gastric volume estimation was useful to assess preoperative bedside gastric content.

A comparison of the diagnosis of gastroparesis in 4 h pediatric gastric emptying studies versus 2 h studies.

BACKGROUND: In adults, there is a consensus for standards to diagnose gastroparesis utilizing a gastric emptying study as the key diagnostic modality but there is no consensus for a standard in pediatrics. Additionally, some cost savings might be achieved if symptoms could be utilized to predict patients with gastroparesis. The aims of the current study were to confirm the sensitivity of a 4 h study in the pediatric population and to assess whether the severity of symptoms were predictive of delayed gastric emptying. STUDY: This was a single site, two part study. In the first part, results were reviewed for all patients who had completed a 4-h, solid gastric emptying study over the course of a 3 year period. In the second portion of the study, participants scheduled for a gastric emptying study, completed a modified GCSI questionnaire. RESULTS: Out of a total of 109 participants, at 2 h, 14 participants (12.8%) had abnormal studies as compared to 26 (23.85%) participants who had abnormal studies at 4 h (p = .0027). Of the 95 participants with normal studies at 2 h, 15% (14/95) were abnormal at 4 h. There were no differences in symptom severity scores between those with slow and those with normal emptying at either 2 h or 4 h. CONCLUSIONS: Our study adds independent confirmation that extending studies from 2 to 4 h increases the diagnostic yield and should be the standard in children and adolescents as it is in adults.

Intragastric Meal Distribution During Gastric Emptying Scintigraphy for Assessment of Fundic Accommodation: Correlation with Symptoms of Gastroparesis.

Impaired fundic accommodation (FA) limits fundic relaxation and the ability to act as a reservoir for food. Assessing intragastric meal distribution (IMD) during gastric emptying scintigraphy (GES) allows for a simple measure of FA. The 3 goals of this study were to evaluate trained readers' (nuclear medicine and radiology physicians) visual assessments of FA from solid-meal GES; develop software to quantify GES IMD; and correlate symptoms of gastroparesis with IMD and gastric emptying. Methods: After training to achieve a consensus interpretation of GES FA, 4 readers interpreted FA in 148 GES studies from normal volunteers and patients. Mixture distribution and κ-agreement analyses were used to assess reader consistency and agreement of scoring of FA. Semiautomated software was used to quantify IMD (ratio of gastric counts in the proximal stomach to those in the total stomach) at 0, 1, 2, 3, and 4 h after ingestion of a meal. Receiver-operating-characteristic analysis was performed to optimize the diagnosis of abnormal IMD at 0 min (IMD0) with impaired FA. IMD0, GES, water load testing, and symptoms were then compared in 177 patients with symptoms of gastroparesis. Results: Reader pairwise weighted κ-values for the visual assessment of FA averaged 0.43 (moderate agreement) for normal FA versus impaired FA. Readers achieved 84.0% consensus and 85.8% reproducibility in assessing impaired FA. IMD0 based on the division of the stomach into proximal and distal halves averaged 0.809 (SD, 0.083) for normal FA and 0.447 (SD, 0.132) (P < 0.01) for impaired FA. On the basis of receiver-operating-characteristic analysis, the optimal cutoff for IMD0 discrimination of normal FA from impaired FA was 0.568 (sensitivity, 86.7%; specificity, 91.7%). Of 177 patients with symptoms of gastroparesis, 129 (72.9%) had delayed gastric emptying; 25 (14.1%) had abnormal IMD0 Low IMD0 (impaired FA) was associated with increased early satiety (P = 0.02). Conclusion: FA can be assessed visually during routine GES with moderate agreement and high reader consistency. Visual and quantitative assessments of FA during GES can yield additional information on gastric motility to help explain patients' symptoms.

Objective assessment of delayed gastric emptying using gastric scintigraphy in post pancreaticoduodenectomy patients.

BACKGROUND: No objective assessment of delayed gastric emptying is carried out in patients undergoing Whipple's procedure. All definitions and criteria along with evaluation of incidence of delayed gastric emptying are based on subjective assessment of the patient with clinical overview, so this study was carried out for an objective and accurate assessment of delayed gastric emptying in post Whipple's patients using gastric scintigraphy. METHODS: Twenty-one patients undergoing Whipple's procedure performed by a single surgeon in a tertiary referral centre were included in the study. Gastric scintigraphy was performed preoperatively and on post-operative 10th and 21st days. Preoperative and post-operative gastric scintigraphy findings were used for the diagnosis of delayed gastric emptying and it was correlated with the incidence of clinical diagnosis of delayed gastric emptying. RESULTS: Thirteen out of 21 patients had clinical delayed gastric emptying. When compared with clinical delayed gastric emptying, the sensitivity, specificity, positive and negative predictive values of post-operative 10th day gastric scintigraphy were 61.53, 100, 100 and 61.53%, respectively (P = 0.004). The sensitivity, specificity, positive and negative predictive values of post-operative 21st day gastric scintigraphy were 38.46, 100, 100 and 50%, respectively (P = 0.04). Reflux across the gastrojejunal anastomosis was noted in 28.5% on dynamic scintigraphy with the severity of clinical symptoms related directly with the degree of reflux. No correlation was seen between delayed gastric emptying and variables such as diabetes mellitus, hypertension and pancreaticojejunal anastomotic leaks. CONCLUSIONS: Gastric scintigraphy may be used to diagnose delayed gastric emptying more objectively in post Whipple's patients.

Gastric motility and emptying assessment by magnetic resonance imaging after lung transplantation: correlation with gastric emptying scintigraphy.

PURPOSE: Gastroparesis is a frequent gastrointestinal complication after lung transplantation. Although gastric emptying scintigraphy (GES) is the standard technique to evaluate gastroparesis, magnetic resonance imaging (MRI) can also assess gastric motility and emptying. This study compared the results obtained by these two modalities. METHODS: Twenty-two lung transplant recipients underwent MRI and GES after ingesting a small pancake as a test meal. Parameters assessed on MRI included antral peristaltic wave velocity and frequency, and the ratios of gastric content volume at 15 and 35 min. GES parameters included retention rates (RR) in the stomach at 30, 60, and 120 min (RR30, RR60, and RR120) and half-time of emptying (T1/2) calculated by exponential curve fitting. Correlations between MRI and GES results were evaluated. RESULTS: Peristaltic wave velocity showed significant moderate negative correlations with RR120 (r = - 0.58, p < 0.05) and T1/2 (r = - 0.60, p < 0.05), indicating an association between reduced velocity and prolonged gastric emptying. Gastric content volume ratios on MRI showed significant moderate positive correlations with RR30 (r = 0.46, p < 0.05), RR60 (r = 0.60, p < 0.01), and T1/2 (r = 0.60, p < 0.01). There were no significant correlations between peristaltic wave frequency and GES parameters. MRI and GES parameters did not differ significantly between the six patients with and the 16 without upper gastrointestinal symptoms. CONCLUSIONS: MRI-based determinations of gastric motility and gastric emptying correlate with GES-based gastric emptying in lung transplant recipients, suggesting that MRI is useful for evaluating patients with gastroparesis.

Normal Values and Clinical Use of Bedside Sonographic Assessment of Postoperative Gastric Emptying: A Prospective Cohort Study.

BACKGROUND: GI dysfunction is common after abdominal surgery. However, assessment and diagnosis currently lack objective measurement. OBJECTIVE: The purpose of this study was to evaluate the feasibility and clinical use of bedside sonographic assessment of gastric emptying by measuring the time to complete emptying of a standard volume of ingested water in patients after colorectal surgery. DESIGN: This was a prospective cohort study. SETTINGS: The study was conducted at a single tertiary institution in Sydney. PATIENTS: Healthy volunteers (n = 30) were studied to establish a reference range. Gastric emptying was then measured in patients (n = 39) before and after colorectal surgery. INTERVENTION: Assessment of gastric emptying was performed on days 1 to 4 by measuring antral cross-sectional area every 10 minutes after ingestion of 250 mL of water. MAIN OUTCOME MEASURES: The time to complete emptying of water was used as a surrogate measure of gastric emptying. Information concerning postoperative outcomes, GI symptoms, and recovery was also recorded. RESULTS: The median time to complete emptying of water for healthy volunteers was 20 minutes (range, 10-40 minutes). The study protocol was completed in 30 of 39 patients. The time to complete emptying of water on day 2 had the best discriminatory power to identify patients with ileus (sensitivity, 85.71%; specificity, 82.61%). Gastric emptying was normal in 20 of 30 (67%) patients, with only 1 case of ileus (false negative). These patients had less nausea (p = 0.0003), earlier intake of solid diet (p = 0.001), and shorter hospital stay (p = 0.040) compared with patients with abnormal gastric emptying. LIMITATIONS: Ultrasound is operator dependent with a learning curve. CONCLUSIONS: Bedside sonographic assessment of gastric emptying is feasible and reliable. Assessment of antral contents with a single ultrasound 40 minutes after ingestion of water enables classification of patients into those with normal and abnormal gastric emptying. When performed on postoperative day 2, it has good sensitivity/specificity for discriminating patients with ileus.

Assessment of gastric emptying in children: Establishment of control values utilizing a standardized vegetarian meal.

BACKGROUND AND AIM: Disorders of gastric emptying constitute an important group of conditions in children. The diagnostic gold standard is scintigraphy, and recommendations for standardization have been published with adult normative data. Pediatric literature lacks standardized age specific normative values. Our aim was to establish normal values of solid phase gastric emptying utilizing scintigraphy in children (5-18 years) using the recommended imaging protocol and standardized meal. METHODS: Gastric emptying was assessed by scintigraphy of a (99m) Tc-labeled vegetarian meal. Image acquisition was dynamic for first hour and static at 2, 3, and 4 h. Results were reported as percent intragastric retention; lag phase defined as time to 5% emptying. RESULTS: Thirty (17 boys) healthy children, mean ages of 9.5 ± 3.1 (range 5 to 16) years, were enrolled. Median values (5th and 95th percentiles) for percent gastric retention at 30 min, 1, 2, 3 and 4 h were 90% (76 and 100%), 77% (56 and 96%), 33% (10 and 71%), 16% (3 and 44%), and 7% (0.5 and 22%). The median (5th and 95th percentiles) lag phase was 18 min (6 and 60 min). Lag phase had no correlation with gastric retention at 4 h. CONCLUSIONS: This study provides valuable normative ranges for solid phase gastric emptying in children. Using adult normative data in children may be inappropriate.

In vivo ultrasound assessment of gastric emptying in newborn mice.

OBJECTIVES: The aim of the present study was to develop an ultrasonographic approach to comparatively assess gastric emptying in newborn wild-type and guanosine triphosphate cyclohydrolase knockout hph-1 mice, because we previously reported gastroparesis early in life in this strain. METHODS: Stomach transverse, anteroposterior, and longitudinal ultrasonographic measurements were obtained with a 40-MHz transducer in pups immediately after maternal separation and 4 hours later. A conventional equation was used and the predicted values validated by obtaining postmortem gastric content volume measurements. Wild-type and hph-1 mice gastric emptying rates were comparatively evaluated at 1 to 3 and 5 to 8 days of age, respectively. RESULTS: The ultrasound equation closely predicted the newborn stomach content volumes with a correlation coefficient (R) of 0.93 and 0.81 (P < 0.01) for measurements obtained on full stomach and after 4 hours of fasting, respectively. In wild-type mice, gastric emptying was age dependent and associated with a greater residual volume at 1 to 3 days (65% ± 7%), as compared with 5- to 8-day-old pups (33% ± 4%; P  < 0.01), after fasting. In contrast, an equal duration of fasting resulted in a significantly greater residual gastric content volume in 5- to 8-day-old hph-1 mice (68%  ± 7%; P < 0.01), as compared with same-age wild-type mice. CONCLUSIONS: Ultrasonography offers a sensitive and accurate estimate of gastric content volume in newborn mice. In wild-type newborn mice, gastric emptying rate is age dependent and significantly reduced in the immediate postnatal period. The newborn hph-1 mice have a significantly higher gastric residual volume, as compared with wild-type same-age animals.

Clinical assessment of delayed gastric emptying and diabetic complications using gastric emptying scintigraphy: involvement of vascular disorder.

AIM: Delayed gastric emptying, including gastroparesis, is a common complication in diabetes mellitus. The association between delayed gastric emptying and overall diabetic complications remains to be studied in detail. We analysed this association. METHODS: We performed gastric emptying scintigraphy of (99m) Tc-diethylenetriaminepentaacetic acid in 34 patients with diabetes to measure the gastric emptying half-times (T1/2) of the whole stomach (WS), proximal stomach (PS) and distal stomach (DS). We assessed T1/2, diabetic-related factors and complications. RESULTS: The prevalence of autonomic neuropathy was higher in the group with delayed T1/2 of the WS than in the normal group. Analysis of intima-media thickness (IMT) and ankle brachial pressure index (ABI), which are risk indicators for vascular disorder, showed that IMT of the carotid bulb was greater in the group with delayed T1/2 of the WS than in the normal group (2·41 mm [1·50-2·81] versus 1·40 mm [0·81-2·08], P = 0·015). T1/2 of the WS correlated positively with IMT of the carotid bulb (r = 0·391, P = 0·027) and negatively with ABI (r = -0·389, P = 0·028). These correlations were mainly attributed to PS and were the same in patients without autonomic neuropathy. In seven of nine patients who received scintigraphy again after diabetic treatment, glycosylated haemoglobin (HbA1c) levels decreased and T1/2 of the WS shortened compared with before treatment. CONCLUSION: Vascular disorder, among other cofactors such as autonomic neuropathy, could be involved in the pathophysiology of delayed gastric emptying. Medium- to long-term glycaemic control was associated with gastric emptying.

Gastroparesis in children: the benefit of conducting 4-hour scintigraphic gastric-emptying studies.

BACKGROUND AND AIM: Scintigraphic gastric emptying study (GES) is the criterion standard for diagnosis of gastroparesis. Adult studies demonstrated that extending GES to 4 hours increases its ability to diagnose delayed gastric emptying. Most pediatric centers assess GES up to 2 hours postmeal. The aim of the present study was to assess the effect of extending GES from 2 to 4 hours in evaluation of children with suspected gastroparesis. METHODS: We conducted a chart review of all children who had a 4-hour GES with standard radiolabeled solid meal in 2009-2010. Results of GES at 1, 2, and 4 hours were compared. Patients were diagnosed as having gastroparesis using adult criteria: if gastric retention of meal was >90%, 60%, and 10% at 1, 2 and 4 hours, respectively. A telephone survey assessed GES time at top 20 pediatric gastroenterology centers in the United States. Cost of evaluation of patients diagnosed as having gastroparesis was estimated. Full-time equivalents of nuclear medicine technicians and number of nuclear medicine studies done at Ann & Robert H. Lurie Children's Hospital of Chicago from 2007 to 2010 were examined. RESULTS: A total of 71 patients (32 boys, average age 10.8 years) were studied. Sixty-two percent (n=44) children had abnormal GES; 23% (8/35) of them who had normal values at 2 hours had abnormal GES at 4 hours (P<0.0001). Twenty-eight percent of patients had delayed GES at 1 hour: all persisted to have abnormal GES at 2 and 4 hours. Cost of evaluation of a child for gastroparesis was $9014. Only 5 of the top 20 pediatric gastroenterology centers in the United States conducted 4-hour GES. Transitioning from 2 hours to 4 hours only required scheduling adjustments and did not result in limitation in the number of scheduled patients. CONCLUSIONS: Extending GES to 4 hours results in a considerable increase in diagnosis of gastroparesis.

Assessment of symptoms during gastric emptying scintigraphy to correlate symptoms to delayed gastric emptying.

BACKGROUND: Symptoms of gastroparesis based on patient recall correlate poorly with gastric emptying. The aim of this study is to determine if symptoms recorded during gastric emptying scintigraphy (GES) correlate with gastric emptying and with symptoms based on patient recall. METHODS: Patients undergoing GES completed the Patient Assessment of GI Symptoms (PAGI-SYM) assessing symptoms over the prior 2 weeks and a questionnaire for which patients graded six symptoms during GES. A Symptom Severity Index (SSI) represented the mean of six symptoms at each time point. KEY RESULTS: A total of 560 patients underwent GES for clinical evaluation of symptoms. Of 388 patients included in the study: 232 patients had normal GES (NGES), 156 delayed GES (DGES), and 11 rapid GES (RGES). Symptom severity index increased pre to postprandial for each group: NGES: 0.51 +/- 0.07 to 0.92 +/- 0.03, DGES: 0.60 +/- 0.09 to 1.13 +/- 0.05, and RGES: 0.56 +/- 0.12 to 0.79 +/- 0.13. Delayed gastric emptying scintigraphy patients had a higher postprandial SSI than NGES patients (1.13 +/- 0.05 vs 0.92 +/- 0.03, P < 0.05). Postprandial symptoms of stomach fullness (1.9 +/- 0.12 vs 1.5 +/- 0.09; P = 0.011), bloating (1.4 +/- 0.11 vs 1.1 +/- 0.09; P = 0.033), and abdominal pain (1.1 +/- 0.08 vs 0.7 +/- 0.12; P = 0.012) were higher in DGES than NGES. Symptom severity based on PAGI-SYM for 2 weeks prior to GES correlated with symptoms during the test for nausea (NGES, r = 0.61; DGES, r = 0.70), stomach fullness (NGES, r = 0.47; DGES, r = 0.60), and bloating (NGES, r = 0.62, DGES, r = 0.66). CONCLUSIONS & INFERENCES: Stomach fullness, bloating, and abdominal pain recorded during GES were higher in patients with delayed gastric emptying than in patients with normal gastric emptying. Symptoms recorded during GES correlated with those during daily life by patient recall.

Assessment of gastric emptying and small-bowel motility: scintigraphy, breath tests, manometry, and SmartPill.

Gastric and small-bowel dysfunction can include gastroparesis, functional dyspepsia, and even irritable bowel syndrome. Patients with symptoms suggesting these disorders are commonly encountered by a variety of physicians, especially gastroenterologists. In most patients, the physical examination and upper endoscopy are normal, and thus symptoms are suggested to be from a motility disorder or a functional gastrointestinal disorder. Further evaluation directed at evaluating the stomach and small-bowel motility may help the clinician to arrive at a correct diagnosis enabling proper treatment of the patient. This article covers several tests that are used to evaluate gastric and small-bowel motility in patients, either in clinical evaluation or in clinical research.

Ultrasonographic assessment of gastric motility in diabetic gastroparesis before and after attaining glycemic control.

BACKGROUND: Glycemic control is important for maintaining gastric motility in diabetic patients, but gastric motility has not yet been studied ultrasonographically in relation to glycemic control. METHODS: We made such observations before and after establishing glycemic control in diabetic patients with gastroparesis. We studied 30 diabetic patients with upper abdominal digestive symptoms who were hospitalized for correction of poor blood sugar control and who underwent upper digestive tract endoscopy to rule out structural causes such as gastric/duodenal lesions. Gastric motility was evaluated by transabdominal ultrasonography, using a test meal, before and after attainment of glycemic control (within 3 days after admission and 3 days before discharge). Also, upper abdominal digestive symptoms present on admission and at discharge were compared. RESULTS: After glycemic control was established, contractions of the antral region were more frequent than before the attainment of control (8.93 +/- 1.17/3 min vs 7.63 +/- 2.22/3 min, respectively; P < 0.001). Glycemic control also significantly improved gastric emptying (before glycemic control, 49.2 +/- 14.8%; after, 67.1 +/- 11.5%; P < 0.001). This was also true for the motility index, concerning antral gastric contractility (before control, 2.97 +/- 1.57; after, 3.75 +/- 1.09; P < 0.05). Upper abdominal symptom scores were also significantly lower after attainment of control than before (0.47 +/- 0.78 vs 3.17 +/- 2.00, respectively; P < 0.001). CONCLUSIONS: These findings suggest that attaining glycemic control improves gastric motility and attainments upper abdominal symptoms in diabetic patients with gastroparesis.

Gastric emptying rate assessment based on the proportion of intra-abdominal radioactivity in the stomach.

UNLABELLED: Using scintigraphic techniques, the rate of gastric emptying is calculated by quantifying the absolute radioactivity within a gastric region of interest (intragastric method) with the time of meal completion considered 100% retention. However, this technique has significant limitations arising from subject movement and radionuclide gamma-ray attenuation, which may render curve fitting difficult, particularly in patients with gastroparesis. In an attempt to minimize these limitations, we have expressed the intragastric content as a percentage of the total abdominal radioactivity (abdominal method) and compared these two methods. METHODS: Forty-five subjects in a sitting position consumed a meal consisting of two fried eggs labeled with 99mTc, two slices of toast and 300 mL 5% glucose water (412 kcal). Data were acquired at a rate of one frame every 5 min from the left anterior oblique view. Using the two methods, the intragastric retention ratios at 30, 60, 90, 120 and 240 min and the 50% emptying time (T50) were obtained from both observation and calculation by power exponential fit. R2, representing goodness of fit of the nonlinear curve fitting, was calculated. RESULTS: There were no differences in the calculated values of T50 between the two methods. Quantitative estimates of T50 by extrapolation of a power exponential fit were feasible in 42 of the 45 subjects when the abdominal method was used, compared with only 29 of the 45 subjects when the intragastric method was used. In the 23 subjects with delayed emptying, quantitative estimates of T50 were feasible in 20 subjects when the abdominal method was used, compared with 7 subjects when the intragastric method was used. Using the abdominal method as opposed to the intragastric method also significantly improved R2. The difference between observed values and estimated values of T50 and intragastric retention ratios at 30, 90 and 120 min was smaller using the abdominal method. CONCLUSION: Scintigraphic measurement of gastric emptying calculated using the proportion of the abdominal radioactivity in the stomach offers substantial advantages over conventional methods, particularly in patients with gastroparesis.