2040. Pancreatic Cyst Prevalence and Detection with Photon Counting CT Compared with Conventional Energy Integrating Detector CT
Authors * Denotes Presenting Author
  1. Jesi Kim *; NYU Langone Health
  2. Alec Megibow; NYU Langone Health
  3. Bari Dane; NYU Langone Health
Conventional CT with energy integrating detectors (EID) requires a two-step conversion from photon to light to electrical signal whereas photon counting CT (PCCT) directly converts x-ray photons to electrical signal. Consequently, PCCT allows for increased spatial resolution than conventional multidetector CT with EID. The prevalence of pancreatic cysts detected on multidetector CT with EID is 2.6% whereas the detection rate on MRI is approximately 15%. The purpose of this study is to calculate the prevalence of pancreatic cysts on PCCT and compare with that of conventional EID CT.

Materials and Methods:
A HIPAA-compliant, IRB-approved retrospective query of a single institution clinical database identified all contrast-enhanced abdominal PCCT performed between 4/11/2022 and 7/26/2022. The presence and size of pancreatic cysts were recorded. In patients with PCCT reported pancreatic cysts, prior CT imaging (EID) was reviewed for reported pancreatic cysts. A one sample Z test with exact binomial proportions was used to compare the PCCT pancreatic cyst prevalence with the literature reported pancreatic cyst CT prevalence. Mann-Whitney U test was used to compare cyst size for PCCT and EID described pancreatic cysts. A p < .05 indicated statistical significance.

Our pancreatic cyst detection rate was 4.8% (56/1194, 95% CI 3.63-6.14%), and it was statistically higher (p < .001) than the rate previously reported in literature (2.6%, n = 2832). Of the 28 pancreatic cysts that had a prior contrast-enhanced EID CT, 16 (57.1%) were described on the prior EID CT, 10 (35.7%) were not described on the prior EID CT, and 2 (7.1%) were new from the prior study. Mean [SD] pancreatic cyst size was 12.7 [8.6] mm for PCCT (n = 56) and 14.4 [12.5] mm for EID (n = 16), p = .56. PCCT pancreatic cyst size was 14.4 [12.5] mm for cysts described on prior EID CT and 8.8[3.6]mm for cysts not described on prior CT (p = .21).

PCCT afforded significantly greater pancreatic cyst detection than conventional EID CT. With its improved pancreatic cyst detection, PCCT could be preferentially utilized instead of EID CT for pancreatic screening.