Presentation Authors: Karlisa Crooks*, Victoria Durojaiye, Ben Horsburgh, Epsom, United Kingdom
Introduction: Computed Tomography of the kidneys, ureters and bladder (CT KUB) is the favoured imaging technique to confirm diagnosis of urinary tract calculi. According to Virtual Radiologic Standard Imaging Protocol, the anatomical scanning region of the KUB starts at the top of the liver on inspiration and ends at the pubis symphysis. If this protocol is not followed, patientsâ€™ have a higher risk of being exposed to unnecessary amounts of radiation. This is especially concerning because breast tissue, multiple mediastinal organs, and gonadal tissue are likely to be at risk. This study aims to find the correlation between adherence to the established protocol of CT KUB scanning and patient overexposure to radiation.
Methods: A retrospective CT KUB review was performed on 172 patients from 2 NHS sites for the month of January 2018. Patient distribution was equal across both sites. Patient data was accessed using the clinical database manager and distance measurements were taken from the CT scan images in the coronal view using the appropriate tool. For each patient, we recorded the gender, age, hospital site, time of CT, position, field of view (FoV), radiation dose, and measured the distance of the anatomical regions exposed in millimetres.
Results: Of the 172 patients that were scanned, only 9% were appropriately exposed. 3% were over exposed to radiation above the liver, 49% below the pubis symphysis and 39% for both. 71% of patients were in the prone position while 29% were in the supine position. Although 29% of patients were scanned in the supine position, the median dose of radiation in this population was greater than that of patients in the prone position. Even though data shows that male patients were over- scanned across sites, the dose of radiation across gender appears to be insignificant. Though medical professionals scanned patients outside working hours, this did not correlate with increased over exposure to radiation.
Conclusions: A substantial amount of patients are being exposed to avoidable radiation doses during a CT KUB because the Virtual Radiologic Standard Imaging protocol is not being followed diligently. More patients were over- scanned inferior to the pubis symphysis than superior to the top of the liver. It is imperative that radiologist remain in the appropriate anatomical regions to avoid undesirable radiation exposure to patients.