Abstract
INTRODUCTION: When there is medial displacement of the gastric bubble on chest X-ray, splenomegaly is frequently suggested as the etiology of this finding. Data to support this association are lacking. We sought to compare the gastric bubble location in patients with and without splenomegaly. METHODS: We identified individuals who had a chest X-ray done concurrently with a CT scan noting a measured splenic index. A concurrent X-ray was defined as having been within +/− 30 days of the CT scan. The data source was a convenience sample from a radiology query at our facility including scans between January 2003 and July 2012. Splenomegaly was defined as a splenic index of > 480 ml. We then reviewed chest X-rays and assessed for a visible gastric bubble. The gastric bubble location was noted as (1) the distance from the apex of the gastric bubble to the left lateral chest wall and (2) as a ratio of the distance of the apex to left lateral chest wall, to the total transverse distance across the chest at the level of the apex of the bubble. Statistical analysis to compare mean ratios between patients with and without splenomegaly, as well a correlation between splenic index and the displacement ratio was conducted. RESULTS: Preliminary results demonstrate, 223 cases were found to have a measured splenic index with a corresponding concurrent chest X-ray demonstrating presence of gastric bubble. Mean age was 39.5 years, with a gender distribution of 74.4% male and 25.6% female, which is reflective of the overall patient base at our institution. Of the 223 patients identified, only 12 had splenic indexes < 480 ml (additional data will be available for presentation). Mean splenic index was 1022.31 ml (range of 39–8588 ml, SD 825.68), with a mean gastric bubble ratio of 0.28 (range 0.08–0.47, SD 0.05). Differences in gastric bubble ratios in patients with and without splenomegaly, 0.2851 and 0.2853, respectively, were not statistically significant (P = .99, CI −0.03–0.03). When viewed as a continuous variable, there was only a weak association between splenic index and gastric bubble ratio using Pearsons r (r = 0.167, P = .01). CONCLUSIONS: Our results refute the commonly held assertion that a medially displaced gastric bubble is suggestive of splenomegaly. There was no statistical significance between the mean ratios in patients with and without splenomegaly. However, there is a weak correlation between splenic size and position of the gastric bubble. Additional data analysis is ongoing in an effort to better test our hypothesis and to test whether an association between gastric bubble location and varying degrees of splenomegaly is present.