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

Abstract

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. 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 (IMD) with impaired FA. IMD, GES, water load testing, and symptoms were then compared in 177 patients with symptoms of gastroparesis. 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. IMD 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) ( < 0.01) for impaired FA. On the basis of receiver-operating-characteristic analysis, the optimal cutoff for IMD 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 IMD Low IMD (impaired FA) was associated with increased early satiety ( = 0.02). 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.

Gastric accommodation measurements by single photon emission computed tomography and two‐dimensional scintigraphy in diabetic patients with upper gastrointestinal symptoms

“…The sample size used in our study was almost identical and the patient population similar to that in the prior study by Orthey et al 19 One limitation of our study is that the cutoff used for abnormal IMD 0 was based on the prior publication 19 and has not been confirmed in our laboratory; using the 0.568 cutoff based on radioactivity counts, only 14.7% of the cohort in our study had reduced GA, in contrast to the 39% identified by SPECT imaging. Further studies are, therefore, required to define the cutoff for abnormal IMD 0 .…”

“…In addition, we used 2 * 2 tables to assess the correlation between SPECT GA normal/abnormal [based on cutoff values of 428 mL for AV and 2.62 for GVR 17 and the reported cutoff (0.568) for IMD 0 ]. 19 We used Student's t test to compare stomach parameters between those with and those without the UGI symptom clusters; data are provided as mean ± SD; P < 0.05 was considered statistically significant.…”

“…We performed regression analyses to assess relationships between IMD 0 measurements or estimated volumes and GA expressed as AV and GVR. In addition, we used 2 * 2 tables to assess the correlation between SPECT GA normal/abnormal [based on cutoff values of 428 mL for AV and 2.62 for GVR and the reported cutoff (0.568) for IMD 0 ] …”

“…Magnetic resonance imaging measurements have also been described but have not been applied widely. More recently, Orthey et al have proposed the use of intragastric distribution of the radiolabeled meal (IMD) immediately after ingestion (IMD 0 ) as a method to assess GA based on two‐dimensional (2D) scintigraphy . Although not validated in relation to a gold standard such as the barostat or SPECT or MRI, it was proposed that IMD 0 scintigraphic counts <0.568 of total gastric counts indicate impaired GA …”

“…Magnetic resonance imaging measurements have also been described 18 as a method to assess GA based on two-dimensional (2D) scintigraphy. 19,20 Although not validated in relation to a gold standard such as the barostat or SPECT or MRI, it was proposed that IMD 0 scintigraphic counts <0.568 of total gastric counts indicate impaired GA. 19 Our aim was to compare the validated SPECT measurement of GA to IMD 0 in individuals with DM1 or DM2 with UGI symptoms who had previously undergone gastric emptying (GE) and GA measurements.…”