Ultrasound quantification of gallbladder volume to establish baseline contraction indices in healthy adults: A pilot study

Introduction Gallbladder contractility helps clinicians assess morbidity and the presence of some hepatobiliary diseases. No such study to the best of knowledge has been conducted in Africa bearing in mind possible racial variations. Aims To evaluate the gallbladder contraction indices in adult Nigerians and derive prediction formulas for gallbladder contraction index in healthy adults in order to help the assessment of gallbladder diseases . Methods The length, width and height of the gallbladder of 50 normal subjects (29 males and 21 females) in Ebonyi State, Nigeria were measured by real time ultrasonography between January and November 2005. The gallbladder volume was calculated using the ellipsoid formula. Gallbladder contraction index (GBCI) taken at the 10th and 20th minute following the ingestion of a standardized fatty meal (SFM) was obtained from the 50 subjects and the mean of the two values adopted as the actual GBCI. Pearson’s correlation established relationship between GBCI and anthropometric variables and a t-test was carried out between the GBCI of males and females. Regression equations were established. Tests were two tailed with P<0.05 indicating statistical significance. Results The mean GBCI (± SD) was 42.8% (± 19.33%) in males and 37.66% (± 16.29%) in females. No statistically significant difference exists between GBCI in males and females (P>0.05). Equations comparing GBCI with subject anthropometric variables based on simple linear regressions gave GBCI (%) = 110.94 (subject height) m + 236.38 for males and GBCI (%) = 0.7646 (weight) kg + 82.7798 for females. Height correlates better with GBCI in males and weight in females Conclusion This study has established prediction equations for GBCI in this locality and could be useful in the assessment of gallbladder diseases. This will impact on patient management and diagnosis as cut off values established or predicted should help in assessing prognosis in patients with gallbladder diseases.