CT protocols and radiation doses for hematuria and urinary stones: Comparing practices in 20 countries.

Purpose: Patients with hematuria and renal colic often undergo CT scanning. The purpose of our study was to assess variations in CT protocols and radiation doses for evaluation of hematuria and urinary stones in 20 countries.

Method: The International Atomic Energy Agency (IAEA) surveyed practices in 51 hospitals from 20 countries in the European region according to the IAEA Technical cooperation classification and obtained following information for three CT protocols (urography, urinary stones, and routine abdomen-pelvis CT) for 1276 patients: patient information (weight, clinical indication), scanner information (scan vendor, scanner name, number of detector rows), scan parameters (such as number of phases, scan start and end locations, mA, kV), and radiation dose descriptors (CTDI, DLP). Two radiologists assessed the appropriateness of clinical indications and number of scan phases using the ESR Referral Guidelines and ACR Appropriateness Criteria. Descriptive statistics and Student's t tests were performed.

Results: Most institutions use 3-6 phase CT urography protocols (80 %, median DLP 1793-3618 mGy.cm) which were associated with 2.4-4.9-fold higher dose compared to 2-phase protocol (20 %, 740 mGy.cm) (p < 0.0001). Likewise, 52 % patients underwent 3-5 phase routine abdomen- pelvis CT (1574-2945 mGy.cm) as opposed to 37 % scanned with a single-phase routine CT (676 mGy.cm). The median DLP for urinary stones CT (516 mGy.cm) were significantly lower than the median DLP for the other two CT protocols (p < 0.0001).

Conclusions: Few institutions (4/13) use low dose CT for urinary stones. There are substantial variations in CT urography and routine abdomen-pelvis CT protocols result in massive radiation doses (up to 2945-3618 mGy.cm).