BACKGROUND: Whole gut transit scintigraphy (WGTS) can detect delayed colonic transit (CT), different types of CT delays, and assess upper GI tract transit.
OBJECTIVE: To delineate the frequency of different types of CT patterns in patients with chronic constipation (CC), determine the relationship between these CT patterns and upper GI tract transit abnormalities, and assess how symptoms relate to different colonic transit patterns.
METHODS: Retrospective review of patients who had WGTS for CC. Patients completed a modified PAGI-SYM questionnaire to assess symptoms. Patients ingested a standard solid (Tc-99m egg sandwich)-liquid (In-111 water) meal to assess solid meal gastric emptying (GE), liquid GE, small bowel transit (SBT), and geometric center of colonic activity at 24, 48, and 72h.
RESULTS: One hundred and eighty six patients underwent WGTS. Main symptoms were constipation (41%), nausea (24%), and bloating (22%). CT assessment showed 32% of patients had normal transit, 31% colonic inertia (CI), 28% functional rectosigmoid obstruction (FRS0), and 9% generalized slow colonic transit (GSCT). GE was delayed in 36%; more commonly in CI and FRSO. SBT was delayed in 19%; more commonly in GSCT and CI. Patients with CI had less bowel movements per week whereas patients with normal CT had more bm/week.
CONCLUSIONS: In this series of patients with symptomatic constipation, WGTS assessment showed delayed colonic transit in 68% of patients, with 31% having colonic inertia, 28% a functional rectosigmoid obstruction pattern, and 9% generalized delay in colonic transit. Abnormalities in GE and SBT were present in 36 and 19%. WGTS is helpful to document delayed colonic transit (CT), assess the pattern of the delay in CT, and determine if there are upper GI transit abnormalities.

UNASSIGNED: The primary objective was to establish the reference values for liquid gastric emptying and small bowel. The secondary objectives encompassed comparing the anterior view and geometric mean methods, assessing gender differences, and exploring potential correlations with age.
UNASSIGNED: Thirty-five consecutive healthy participants (28 females and 7 males) with a mean age of 42 ± 11 years (median, 42; range, 23-65) underwent liquid gastric emptying scintigraphy at five intervals (0, 0.5, 1, 2, and 4 h), with optional additional imaging at 24 h. Liquid gastric emptying was evaluated using percent retention and half-time (T1/2). Small-bowel transit was assessed using the index of small-bowel transit (ISBT), calculated as the ratio of terminal ileal reservoir counts to total abdominal counts at 4 h. Reference values were established based on percentiles or mean and standard deviation (SD). Rapid small-bowel transit was determined through visual inspection. Statistical analysis involved paired Samples t-test or Wilcoxon signed-rank test for comparing imaging methods, independent Samples t-test or Mann-Whitney U-test for gender comparison, and Spearman\'s rank correlation for assessing age-related associations. A 2-tailed P < 0.05 indicated significance.
UNASSIGNED: Rapid liquid gastric emptying based on the geometric mean method was defined as percent retention <8% at 30 min, while delayed emptying as percent retention >33%, >20%, and >4% at 1, 2, and 4 h, respectively. The reference range of T1/2 of gastric emptying was 10-60 min. The reference value for small-bowel transit using the geometric mean method was established as ISBT >30% at 4 h, while rapid small-bowel transit was defined as the first visualization of activity in the cecum-ascending colon within 1 h. Parameters for liquid gastric emptying and small-bowel transit were notably higher in the anterior view method compared to the geometric mean method (P ≤ 0.019), except for percent retention at 2 h (P = 0.510). Nevertheless, the obtained reference values, whether based on percentiles or mean and SD, showed no notable variance between the two methods to warrant clinical significance. Gender did not display an impact on liquid gastric emptying or small-bowel transit in either method (P ≥ 0.173), and age demonstrated no significant moderate or strong correlations (Spearman\'s ρ ≤ 0.397).
UNASSIGNED: The study determined reference values for liquid gastric emptying and small-bowel transit through a standard gastric emptying scintigraphy protocol, avoiding additional complex procedures or extended imaging sessions. The established normative data can apply to individuals of both genders aged ≥18 years. While advocating the geometric mean method as the primary choice, the study acknowledges that in busy centers handling multiple studies with limited resources and a single-head gamma camera catering to multiple studies, the anterior view method remains a feasible alternative.

OBJECTIVE: The purpose of this study is to examine the feasibility of a machine learning (ML) system for optimizing a gastric emptying scintigraphy (GES) protocol for the detection of delayed gastric emptying (GE), which is considered a primary indication for the diagnosis of gastroparesis.
METHODS: An ML model was developed using the JADBio AutoML artificial intelligence (AI) platform. This model employs the percent GE at various imaging time points following the ingestion of a standardized radiolabeled meal to predict normal versus delayed GE at the conclusion of the 4 h GES study. The model was trained and tested on a cohort of 1002 patients who underwent GES using a 70/30 stratified split ratio for training vs. testing. The ML software automated the generation of optimal predictive models by employing a combination of data preprocessing, appropriate feature selection, and predictive modeling analysis algorithms.
RESULTS: The area under the curve (AUC) of the receiver operating characteristic (ROC) curve was employed to evaluate the predictive modeling performance. Several models were developed using different combinations of imaging time points as input features and methodologies to achieve optimal output. By using GE values at time points 0.5 h, 1 h, 1.5 h, 2 h, and 2.5 h as input predictors of the 4 h outcome, the analysis produced an AUC of 90.7% and a balanced accuracy (BA) of 80.0% on the test set. This performance was comparable to the training set results (AUC = 91.5%, BA = 84.7%) within the 95% confidence interval (CI), demonstrating a robust predictive capability. Through feature selection, it was discovered that the 2.5 h GE value alone was statistically significant enough to predict the 4 h outcome independently, with a slightly increased test set performance (AUC = 92.4%, BA = 83.3%), thus emphasizing its dominance as the primary predictor for delayed GE. ROC analysis was also performed for single time imaging points at 1 h and 2 h to assess their independent predictiveness of the 4 h outcome. Furthermore, the ML model was tested for its ability to predict \"flipping\" cases with normal GE at 1 h and 2 h that became abnormal with delayed GE at 4 h.
CONCLUSIONS: An AI/ML model was designed and trained for predicting delayed GE using a limited number of imaging time points in a 4 h GES clinical protocol. This study demonstrates the feasibility of employing ML for GES optimization in the detection of delayed GE and potentially shortening the protocol\'s time length without compromising diagnostic power.

UNASSIGNED: The primary objective was to establish the reference values for small-bowel and colonic transit within the context of the routine standard solid meal gastric emptying scintigraphy (GES). The secondary objective was to compare the small-bowel and colonic transit between the anterior view and geometric mean methods.
UNASSIGNED: Twenty-nine healthy controls underwent routine GES, with additional imaging at 24 h if feasible. Small-bowel transit was assessed using the index of small-bowel transit (ISBT), calculated as the ratio of terminal ileal reservoir counts to total abdominal counts at 4 h. Colonic transit was evaluated using the colonic geometric center (CGC) by dividing the large bowel into four segments, with an additional fifth segment accounting for the eliminated counts. Reference values were established based on the fifth percentile or mean ± 1.96 standard deviations. Rapid small-bowel transit was visually determined. Paired Samples t-test or Wilcoxon signed-rank test, as applicable, was used to compare the small-bowel and colonic transit between the anterior view and geometric mean methods. For comparing small-bowel and colonic transit between females and males, the Independent samples t-test or Mann-Whitney U-test was applied, as appropriate. The correlation between age and small-bowel and colonic transit was assessed using Spearman\'s rank correlation analysis.
UNASSIGNED: The reference value for small-bowel transit using the geometric mean method was established as ISBT >37% at 4 h, whereas rapid small-bowel transit was defined as the first visualization of activity in the cecum-ascending colon within 2 h. For colonic transit, the reference range was established as CGC 2.8-4.4 at 24 h. Comparing the anterior view and geometric mean methods, there were no significant differences in ISBT and CGC values (P ≥ 0.125). Gender did not affect small-bowel and colonic transit in both methods (P ≥ 0.378), and age showed no significant correlations (P ≥ 0.053).
UNASSIGNED: This study determined the reference values for small-bowel and colonic transit in the Indian population using routine GES, avoiding the need for additional complex procedures. The results may be generalized to the Indian population, emphasizing the importance of assessing small-bowel and colonic transit in patients with normal gastric emptying parameters to enhance gastrointestinal transit evaluation.

OBJECTIVE: Gastric emptying scintigraphy (GES) is the criterion standard for the diagnosis of gastroparesis. However, data are lacking regarding the prognostic value of preoperative intragastric meal distribution during GES in patients undergoing gastric peroral endoscopic myotomy (G-POEM) for gastroparesis. This study investigated the association of GES morphologic parameters and the long-term clinical success of G-POEM.
METHODS: This retrospective study included patients who underwent G-POEM for refractory gastroparesis in a tertiary center with preoperative GES data. Intragastric meal distribution was measured using the proximal to distal count ratio (PDCR) at 0, 1, 2 and 4 hours, and the retention index was calculated. Clinical success was defined as a decrease of at least 50% in the Gastroparesis Cardinal Symptom Index total score after G-POEM.
RESULTS: In total, 77 patients were included with a mean follow-up of 40.14 months. Clinical success was observed in 54.55% of patients. The retention index was not associated with clinical success. Only PDCR at 0 hours (PDCR0) was associated with clinical success. In univariate analysis, the median PDCR0 was 6.0 (interquartile range, 5.59) in patients with clinical success and 4.29 (interquartile range, 4.51) in patients with clinical failure (P = .019). In multivariate analysis, PDCR0 >5.25 was associated with clinical success (odds ratio, 4.36; 95% confidence interval, 1.55-12.26; P = .00524).
CONCLUSIONS: This study suggests that in patients with gastroparesis, a high PDCR0 value (suggestive for a preferential fundic meal distribution) during preoperative GES is associated with long-term clinical response to G-POEM.

Several nuclear medicine technologist-specific groups exist on social media sites such as Facebook and LinkedIn. Although these sites provide a valuable resource and forum for technologists to interact and pose questions, any recommendations, especially those regarding patient care, should be carefully scrutinized and evaluated on the basis of scientific merit and not opinion. Recently, an assortment of unvalidated ingredients for solid-meal gastric emptying scintigraphy has been suggested on these social media sites. Often, these ingredients do not comply with the peer-reviewed guidelines and can potentially produce unreliable results and misdiagnosis. Thus, before implementing advice from an unvetted source, technologists must distinguish between low- and high-quality information. Currency, reliability, authority, and purpose-a test of the trustworthiness of an information source-can help technologists evaluate recommendations and avoid the use of unsupported solid-meal gastric emptying scintigraphy ingredients.

This study aimed to analyze the compliance of health care institutions with the Society of Nuclear Medicine and Molecular Imaging (SNMMI) procedure guidelines for gastric emptying scintigraphy (GES). Methods: A 19-question survey on demographics and the GES protocol was conducted using a Google form. The demographic questions covered position, number of technologists in the department, location, type of health care institution, and number of GES studies per month. The protocol questions included patient preparation, meal preparation, withholding of scheduled medications, radiopharmaceutical type, and radiopharmaceutical dose. The survey was sent to 7 nuclear medicine Facebook groups and a list of clinical affiliates provided by the Indiana University School of Medicine Nuclear Medicine Program. Descriptive statistics were compiled for most questions. A Fisher exact test with a significance level of 0.05 was used to compare the type of health care institution with compliance with the SNMMI GES protocol regarding radiolabeling time, meal preparation, and meal components, as well as to compare the type of health care institution with the number of GES studies performed per institution. Results: In total, 240 people responded to the survey. Most were nonsupervisory nuclear medicine technologists (72%) in nonacademic institutions (72%) and groups with 4 or more technologists (62%). Of the respondents, 72% followed the SNMMI guideline of adding the radiopharmaceutical before cooking, but only 37% followed the meal component guideline. There was no significant association between the type of institution or the number of GES studies and compliance with radiolabeling time or with meal preparation or components. Most respondents asked patients to withhold medications per SNMMI guidelines and used the recommended radiopharmaceutical (99mTc-sulfur colloid, 95%) at the recommended dose (18.5-37 MBq, 84%). Conclusion: Although most respondents followed most aspects of the SNMMI guidelines for GES, more than half did not use the recommended meal of liquid egg whites. Compliance did not vary between academic and nonacademic institutions or between groups performing a large or a small number of GES studies.

The aim of this study was to assess the rates of undiagnosed diabetes mellitus (DM) and pre-DM in patients undergoing gastric emptying scintigraphy (GES). Diabetes is an epidemic in the United States, and the disease is associated with altered gut motility. As a result, we suspected that a significant number of patients referred for GES may have undiagnosed DM or pre-DM. Given that established procedure standards for GES require all patients to prepare with an 8-h fast, an opportunity is provided to measure the fasting blood glucose (FBG) in all individuals before they undergo the examination. Methods: The charts of patients undergoing GES were reviewed for a history of DM and correlated with FBG and GES results. FBG values, obtained by point-of-care testing, were categorized as normal, pre-DM, or DM. Results: Patients with known DM made up 23% of those referred for GES, and most (55%) had a normal FBG. In those without a history of DM, there were a significant number with undiagnosed pre-DM (12%) and DM (33%). Conclusion: Our study provides the first measure of the likely prevalence of undiagnosed DM and pre-DM and characterizes the different gastric emptying patterns among patients with normal FBG, likely undiagnosed pre-DM, likely undiagnosed DM, and known DM.

The radionuclide gastric emptying study is the gold standard for the diagnosis of gastroparesis. Methods: We performed a retrospective analysis of 510 patients to evaluate how often a diagnosis of slow gastric emptying determined by gastric emptying scintigraphy (GES) changes clinical management at our institution. Results: We found evidence of gastroparesis in 100 patients. A change in management was recommended for 62% within 1 mo of the GES. Conclusion: Our results illustrate the importance of performing GES on patients with clinically suspected gastroparesis.

In 2009, the Society of Nuclear Medicine and Molecular Imaging published a standardized protocol guideline for gastric emptying scintigraphy that contains specific instructions on the exact meal and preparation procedure. Previous research has shown that the standardized meal and proper preparation of the meal for gastric emptying scintigraphy are not being adopted by some facilities. This research explores the differences of radiolabeling in the method of preparation of 99mTc-sulfur colloid (SC)-radiolabeled eggs. Methods: Liquid egg whites were mixed with 99mTc-SC before cooking in conjunction with the standardized protocol. A second sample set was prepared by adding the 99mTc-SC to eggs after they were cooked. Each sample set was placed in a solution of HCl and pepsin to simulate gestation. Radiolabeling efficacy was tested on each sample set at 2 and 4 h after gestating in HCl and pepsin. Results: 99mTc-SC added to the liquid egg whites before microwave cooking yielded radiolabeling efficacy of 70% 99mTc-SC after 2 and 4 h of simulated gastric fluid gestation. In contrast, radiolabeling after cooking the egg whites yielded 50% radiolabeling after simulated gestation. Conclusion: The results from this experiment showed that the method of mixing the 99mTc-SC with liquid egg whites before microwave cooking has higher binding efficacy than when adding 99mTc-SC onto already cooked egg whites. These results highlight the importance of following the standardized protocol for the meal preparation of a gastric emptying study.