Enhanced Gastric Emptying Scintigraphy to Assess Fundic Accommodation Using Intragastric Meal Distribution and Antral Contractility

Abstract

1) Incorporate IMD and DACS into GES; 2) Compare IMD0 using gastric division into anatomic proximal and distal halves vs more physiologic separation of the antrum from proximal stomach using DACS; 3) establish normal values. Normal subjects ( = 20) underwent GES using a solid-liquid meal. DACS (1 frame/3 sec) was performed for 20 minutes after each static imaging time. IMD0 was measured by using both semi-automated software to divide the gastric long axis in anatomic halves and Fourier analysis to identify antral pixels with phasic contractions. Using division of stomach in halves (IMD0(½) averaged 0.75±0.15 (SD). Using phasic contractions to define the antrum, mean IMD0(AC) was 0.85±0.14 ( = 0.004). Sustained antral contractions started at mean 11.24±12.98 minutes after meal ingestion and originated in gastric mid-body with starting location 40.5±10.8% from distal to proximal stomach along its long axis. Antral frequency and ejection fraction peaked 30 minutes after meal ingestion at 3.30±0.71 contractions per minute and EF 30.3±13.69%, when mean antral filling peaked at 36.7±14%. Maximum antral contraction speed was 3.54±0.90 mm/sec at 60 min after meal ingestion. Gastric retention was 39.8±12.8% at 2 hours and 5.8±6.0% at 4 hours. Addition of DACS to GES permits physiologic characterization of both fundic accommodation and antral contractility to supplement routine GES.

Using gastric emptying scintigraphy to evaluate antral contractions and duodenal bolus propagation

“…After the meal ingestion, conventional static imaging using a 128 ϫ 128 matrix was performed at 0, 0.5, 1, 2, 3, and 4 h with the subject upright in the anterior and then the posterior position each for 30 s. DACS was then performed as previously described (14,16) obtaining consecutive 1 s frames in 128 ϫ 128 matrix. DACS was obtained for 10 min after the static imaging first in an anterior projection and immediately followed by 10 min in the right anterior oblique (RAO) projection for comparison to assess optimal visualization of the duodenal sweep.…”

“…DACS analysis. DACS analysis followed that reported by Knight et al (14) and Orthey et al (16). Fast Fourier transform (FFT) of the time activity curve of counts from a vertical regions of interest (ROIs) in the midportion of the antrum was performed.…”

Gastroparesis: a turning point in understanding and treatment

“…A balanced appreciation of both physiology and clinical symptoms is necessary along with mechanistic studies to understand and clinical trials to address symptoms. Furthermore, refinement and development of new techniques for studying the different aspects of gastric function is likely to provide better understanding of the clinical symptoms and develop targeted therapies 12…”

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

“…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.…”