Utility of CT in detecting and monitoring subphrenic jujube pits: a retrospective cross-sectional study of clinical cases and ex vivo experiments

BACKGROUND: Subphrenic jujube foreign body can cause perforation, abscess, peritonitis and other complications. Computed tomography (CT) is considered to be a sensitive tool for small or faintly opaque foreign body (e.g., jujube pits, toothpicks, fish bones, acrylics and plastics) detection. The present study aimed to investigate the clinical and imaging features of subphrenic jujube pits and explore the potential of CT for detecting and monitoring subphrenic jujube pits. METHODS: Patients with subphrenic jujube pits who were treated at our institution were retrospectively reviewed along with published studies. A total of 10 types of commercially available jujube pits were analyzed with CT, then another 40 jujube pits (≥2.5 cm) were randomly selected and soaked in a series of solutions to mimic the gastrointestinal tract processes, following which CT was performed at serial time points with conventional and dual-energy protocols. RESULTS: All jujube pits could be detected by CT, presenting spindle-shape high-density. The length of jujube pits based on clinical cases and that of the commercially available types were 1.38 to 3.50 cm and 1.35 to 3.95 cm, respectively. After analysis, the mean attenuation values derived from the clinical cases [77.67 Hounsfield unit (HU), range: −89.92 to 153.13 HU, SD 64.70 HU] were higher than those of the 10 commercially available types of jujube pits in boiled (73.57 HU, range: 2.29 to 94.96 HU, SD 20.48 HU) and raw state (−274.28 HU, range: −400.12 to −168.12 HU, SD 72.75 HU); statistically significant differences were found in mean attenuation values between raw jujube pits and boiled jujube pits (P<0.05). After soaking, the radiodensity of raw jujube pits showed an upward trend over immersion time, and water (-hydroxyapatite) overlay images enhanced the visualization of jujube pit water content as the percentage of blue area increased over time. CONCLUSIONS: CT plays an important role in evaluating and tracing subphrenic jujube pits.