Comparison of gastric emptying scintigraphy based on the geometric mean of the gastric proportion of the abdominal radioactivity or on the geometric mean of the intragastric radioactivity.
OBJECTIVE
Using gastric emptying scintigraphy the gastric retention rate is commonly calculated within a gastric region of interest (intragastric method). This technique may have significant limitations when left oblique anterior views are acquired, due in part to attenuation resulting from intragastric redistribution. To minimize these drawbacks, it was proposed to express the intragastric content as a percentage of the abdominal radioactivity (abdominal method). Our goal was to compare these two methods when anterior-posterior scanning is used.


METHODS
Antero-posterior scintigraphic data of 272 consecutive patients were analysed by both methods. Retention rates were obtained by both observation and calculation by power exponential fit. Gastric emptying parameters (half-emptying time of solids (T(50,S)) and liquids (T(50,L)), lag phase (T(lag)) time and real emptying time (T(RE))), and quality of fit were also computed and compared.


RESULTS
For solids, the intragastric method resulted in weakly higher experimental retention rates, whereas retention rates were quite similar for liquids. Differences between experimental and calculated retention rates were smaller for abdominal method, for both liquids and solids. As a result, values for the quality of fit were higher for the abdominal method. Significant differences were observed only for calculated T(50,S) (122+/-46 min vs. 124+/-48 min, mean difference 2+/-2 min, P<0.00001) and T(RE) (163+/-64 min vs. 168+/-68 min, mean difference 4.5+/-3.8 min, P<0.05), respectively, for the abdominal and the intragastric methods. However, the Bland-Altman statistical method revealed good agreements (<5% outliers).


CONCLUSIONS
Intragastric and abdominal methods can be used indifferently to treat antero-posterior data of gastric scintigraphy.
Salaun
Pierre-Yves
PY
Department of Nuclear Medicine, University of Brest, France.
Querellou
Solène
S
Nguyen
Jean-Michel
JM
Bodet-Milin
Caroline
C
Carlier
Thomas
T
Turzo
Alexandre
A
Bizais
Yves
Y
Couturier
Olivier
O
D000005:Abdomen / Q000000981:diagnostic imaging; D005260:Female; D005746:Gastric Emptying; D005753:Gastric Mucosa / Q000378:metabolism; D006207:Half-Life; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013270:Stomach / Q000000981:diagnostic imaging; D013272:Stomach Diseases / Q000000981:diagnostic imaging* / Q000378:metabolism*; D013667:Technetium / Q000493:pharmacokinetics*
D019275:Radiopharmaceuticals; D013667:Technetium