Computed tomography use in a large Italian region: trend analysis 2004-2014 of emergency and outpatient CT examinations in children and adults.

OBJECTIVES: To analyse CT use in recent years in a high-density Italian area (±10 million inhabitants, including 1 million children), focusing on developing age. METHODS: Retrospective analysis of records from HealthCare IT System, covering >400 hospitals and clinics. Description of CT use between 2004-2014 in emergency and outpatient care and assessment of radiation exposure trend. RESULTS: Over 9 million scans were performed. Emergency procedures showed a global increase of 230 %, mainly head examinations. In the global outpatient setting, the annual number of CT scans/person increased ±19 %. A moderate increase in CT examinations was observed in the developing age population, while a remarkable increase in dental, chest and abdominal procedures occurred for the 10- to 30-year age range. The increase in mean annual dose/capita in the global patient pool was approximately 42 %, increasing from 0.72-1.03 mSv. The population rate receiving an annual CT radiation dose/capita higher than 1 mSv tripled in the 11-year interval, increasing from 16-48 %. CONCLUSIONS: The remarkable increase in radiation exposure raises a special concern for teenagers and young adults, whose risk tends to be underestimated. The fivefold increase in dental CTs in the younger age groups requires further investigations. KEY POINTS: • Literature highlights a remarkable increase in CT use over the last decades. • The paediatric age had higher exposure to X-ray risk. • A detailed retrospective analysis of more than 9 million scans was performed. • Dental, chest, abdominal procedures increased remarkably in 10- to 30-year age range. • This study raises concern about exposure for teenagers and young adults.

Quality control in cone-beam computed tomography (CBCT) EFOMP-ESTRO-IAEA protocol (summary report).

The aim of the guideline presented in this article is to unify the test parameters for image quality evaluation and radiation output in all types of cone-beam computed tomography (CBCT) systems. The applications of CBCT spread over dental and interventional radiology, guided surgery and radiotherapy. The chosen tests provide the means to objectively evaluate the performance and monitor the constancy of the imaging chain. Experience from all involved associations has been collected to achieve a consensus that is rigorous and helpful for the practice. The guideline recommends to assess image quality in terms of uniformity, geometrical precision, voxel density values (or Hounsfield units where available), noise, low contrast resolution and spatial resolution measurements. These tests usually require the use of a phantom and evaluation software. Radiation output can be determined with a kerma-area product meter attached to the tube case. Alternatively, a solid state dosimeter attached to the flat panel and a simple geometric relationship can be used to calculate the dose to the isocentre. Summary tables including action levels and recommended frequencies for each test, as well as relevant references, are provided. If the radiation output or image quality deviates from expected values, or exceeds documented action levels for a given system, a more in depth system analysis (using conventional tests) and corrective maintenance work may be required.