1. A Stable Isotope Breath Test With a Standard Meal for Abnormal Gastric Emptying of Solids in the Clinic and in Research 
Lawrence A. Szarka, Michael Camilleri, Adrian Vella, Duane Burton, Kari Baxter, Julie Simonson, Alan R. Zinsmeister 
Clinical Gastroenterology and Hepatology 
Volume 6, Issue 6, Pages e1 (June 2008)
DOI: /j.cgh
Copyright © 2008 AGA Institute Terms and Conditions

2. Figure 1
(A) Summary of GE results by t½ group in 129 subjects with clinically suspected delayed GE. Data show mean ± standard deviation. (B) 13CO2 enrichment of breath excreted over 3 hours (right Y-axis, kPCD × 10−2), as well as the observed proportion retained in stomach by scintigraphy (left Y-axis) and the predicted GE based on the mathematical formulas and the 13CO2 excretion measured.
Clinical Gastroenterology and Hepatology 2008 6, e1DOI: ( /j.cgh )
Copyright © 2008 AGA Institute Terms and Conditions

3. Figure 2
Plot of the first canonical variates (linear combinations with maximal correlation) with scintigraphic variate on the Y-axis and the [13C]–S platensis GEBT breath kPCD variate on the X-axis. Specifically, the first canonical variate for the GE proportions (Y-axis) has a strong (negative) relationship with the scintigraphically based t½ values (Spearman correlation of –0.82, P < .001). The first canonical variate of the kPCD values (X-axis) was also strongly related to these t½ values (Spearman correlation of –0.73, P < .001). Because more delayed GE corresponds to larger t½ values, the correlation of these canonical variates with t½ values is negative, reflecting the propensity of the more delayed GE subjects in the lower left quadrant and the more accelerated GE subjects in the upper right quadrant.
Clinical Gastroenterology and Hepatology 2008 6, e1DOI: ( /j.cgh )
Copyright © 2008 AGA Institute Terms and Conditions

4. Figure 3
Scatter plot of the scintigraphically measured GE t½ values (Y-axis) versus the BT-estimated t½ values (X-axis) obtained from linear interpolation of BT-predicted GE proportions. Dotted line shows X = Y.
Clinical Gastroenterology and Hepatology 2008 6, e1DOI: ( /j.cgh )
Copyright © 2008 AGA Institute Terms and Conditions

5. Figure 4
Bland–Altman plot of the differences between scintigraphically measured t½ values and BT-estimated t½ values (Y-axis) versus the average of the 2 t½ values (X-axis) in each subject. Note that subjects with t½ values greater than 240 minutes by scintigraphy are not used.
Clinical Gastroenterology and Hepatology 2008 6, e1DOI: ( /j.cgh )
Copyright © 2008 AGA Institute Terms and Conditions

6. Figure 5
ROC curve for the detection of delayed GE with [13C]–S platensis GEBT measurements relative to the scintigraphic measurement of GE. Note that the performance characteristics are uniformly excellent even with a single breath sample at 150 minutes, but the sensitivity reaches 89% at 80% specificity when the 180-minute sample is also included. AUC for the combined 150- and 180-minute samples was Note also that the 45-minute sample adds little to the accuracy of determination of the GEBT for categorizing delayed GE above the accuracy of the combined 150- and 180-minute breath samples. Combining the 3 time points (45, 150, and 180 minutes) resulted in an AUC of
Clinical Gastroenterology and Hepatology 2008 6, e1DOI: ( /j.cgh )
Copyright © 2008 AGA Institute Terms and Conditions

7. Figure 6
ROC curve for the detection of accelerated GE with BT measurements relative to the scintigraphic measurement of GE. Note the proportion emptied at 45 minutes provides fair sensitivity and specificity, and the best performance is with all 3 breath samples. However, the 45-minute breath sample in combination with the 180-minute sample yielded a sensitivity of 93% at 80% specificity. AUC for the combined 45- and 180-minute samples was Combining the 3 time points (45, 150, and 180 minutes) resulted in an AUC of
Clinical Gastroenterology and Hepatology 2008 6, e1DOI: ( /j.cgh )
Copyright © 2008 AGA Institute Terms and Conditions