J Nucl Med. 2007; 48 (Supplement 2):278P
General Clinical Specialties: Gastroenterology
Gastroenterology Posters |
Percent residual gastric activity at four hours (%RGA@4Hrs) after a solid meal cannot be reliably predicted from 2 hour data
William Mohr1,
Tony Abraham1 and
Malik Juweid1
1 University of Iowa Hospital and Clinics, Iowa City, Iowa
1251
Objectives: Recent reports suggest %RGA@4Hrs after a solid meal should be used to reliably identify patients with delayed gastric emptying (DGE) using a cutoff of 10% , with greater than 10%RGA@4Hrs indicative of DGE and normal gastric emptying with less than or equal to 10%RGA@4Hrs. This study was undertaken to determine if %RGA4Hrs can be accurately determined by extrapolation of the initial 2 hour data. Methods: We analyzed all 83 gastric emptying studies performed from 01/02 to 01/06 in which data was collected at 0, 10, 20, 30, 50, 70, 90, 120, and 240 minutes. Of the 83 patients, gastric emptying half time was found to be less than or equal 120 minutes (min) in 50 (Group I) and greater than 120 min in 33 (Group II) by utilizing linear fitting over decay corrected geometric mean values for each data point through the initial 120 minutes of a standard solid meal. The meal consisted of 2 scrambled eggs containing 1 mCi of 99mTc-sulfur colloid, 1 piece of toast, and 120 ml of water. We determined whether extrapolation of the data obtained up to 2 hours could predict whether the actually measured %RGA@4Hrs was normal versus abnormal (i.e. greater than 10% or less than or equal to 10%). Results: Overall, the accuracy of predicting whether the %RGA@4Hrs was actually greater than 10% or less than or equal to 10% by extrapolation was found to be 70%. The accuracy was higher in Group 1 than Group 2 at 74% and 64% respectively. The correlation between the extrapolated %RGA@4Hrs and the actual %RGA@4Hrs was relatively poor with correlation coefficient (R) = 0.71 and standard error (SE) of 0.12. Conclusions: %RGA@4Hrs can not be reliably predicted from the initial 2 hour data regardless if gastric emptying half-time was greater than 120 minutes or less than or equal to 120 minutes.
