Congress:
EuroSafe Imaging 2019
Keywords:
Action 4 - Dose management systems, Radioprotection / Radiation dose, CT, Dosimetry, Quality assurance
Authors:
M. Longo, V. Cannatà, P. Toma, A. Magistrelli, C. Polito, T. Insero, S. Donatiello, E. Genovese, B. Cassano
DOI:
10.26044/esi2019/ESI-0093
Background/introduction
During the last decades,
the growth in use of medical imaging examinations has led to a significant interest on radiation dose delivered to patients.
Computed Tomography (CT) examinations have been identified as the largest source of medical radiation exposure both in Europe and in United States [1-3].
The main technological advance in CT introduced in the last years has been represented by the multislice scanners (MSCT),
which have contributed to faster acquisition of large anatomical regions limiting the rate of failure of adequate image acquisition.
Despite of the several advantages introduced by MSCT,
the intensive use of this technology has created novel concern to medical physicists and to clinicians about their technical features,
which could significantly affect the patient’s radiation dose.
For spiral scanning,
the scan length comprises the imaged body section and additional regions at the beginning and at the end of the scan (overscanning) that are required for data interpolation to correctly reconstruct the first and the last slice of the imaged region.
The additional X-ray tube rotations do not directly contribute to imaging,
but deliver a dose amount that can represent a critical issue in patient’s exposure to ionizing radiation.
The amount of the extra-dose due to overscanning differs from manufacturers and scanner type and it is affected by several scanning parameters.
In the last years,
several authors focused their efforts on the quantification of overscan dose [4-12].
Despite of these studies,
the still existing lack of the available literature in reporting the exposure due to overscanning and its dependence on scan parameters and acquisition protocols encourage additional studies to be employed.
The aim of the present study was to quantify the absolute value of DLP due to overscanning in MSCT acquisitions as function of scan parameters through a previously validated methodology based on a suspended measurement set-up and related dosimetric formalism [13].