Purpose or Case Report: Diffuse serosal and soft tissue enhancement (SSTE) is a unique pattern of contrast enhancement seen on abdominal radiographs after cardiac catheterization in newborns. While thought to be benign, SSTE can be misdiagnosed as pneumoperitoneum, resulting in unnecessary and potentially invasive diagnostic procedures. The purpose of this study is to describe the incidence of SSTE on abdominal radiograph performed in infants within 2 days of cardiac catheterization and identify clinical features associated with this imaging finding.
Methods & Materials: Patients under 1 year of age who had undergone cardiac catheterization between January 2010 and September 2019 were identified from a cardiology database. Patients with abdominal radiographs performed within 2 days of cardiac catheterization were evaluated by a pediatric radiologist for the presence of SSTE. Laboratory and clinical information, including renal function tests, contrast dose, and patient demographics were recorded. A two-sample t-test and univariate logistic regression analysis were used to determine variables that correlate with SSTE.
Results: 294 patients less than 1 year of age (182 boys; mean age 123 days) who underwent at least one abdominal radiograph within 2 days of catheterization were included in the study. SSTE was found in 37% (108/294). Compared to those without SSTE, patients with SSTE had a higher total contrast volume (p<0.0001) and higher contrast volume per body surface area (BSA) (p<0.0001). Those with SSTE had lower creatinine pre- (p=0.02) and post-catheterization (p=0.047), without a significant difference in calculated GFR at either timepoint (p=0.066 pre-, and p=0.22 post-catheterization). In addition, the mean age (p=0.001), weight (p=0.0013), and BSA (p=0.004) were higher in patients with SSTE. After univariate analysis, pre-catheterization serum creatinine (p=0.03), age at catheterization (p=0.001), weight (p=0.001), BSA (p=0.005), total contrast volume (p < 0.0001), and contrast volume per BSA (p<0.0001) were determined to be significant predictors of SSTE.
Conclusions: SSTE was present on 37% of abdominal radiographs performed on infants within 2 days of cardiac catheterization in our study. A higher total contrast volume and higher contrast volume per BSA were the variables most strongly correlated with the presence of SSTE. Although patients with SSTE have lower creatinine levels, the lack of a statistically significant difference in GFR suggests that SSTE is unlikely to be associated with renal function.