Aims and objectives
The aim of this study is to compare two different low dose protocols (low dose s ultra-low dose) regarding maxillofacial CT in terms of image quality and radiation exposure in a small group of patients.
In our hospital we havesome youngpatients that needs to do this examination so our intent was to decrease the doseparticularly eye lensequivalent dose.
Methods and materials
Twentypatients ( range 32-60 mean age 47)were randomly selected for an ultra-low-dose protocol,
instead of a low-dose protocol.
All patients signed a written informed consent before image acquisition.
Scans were performed with CT GE Revolution EVO 64 slices.
Technical parameters used in the standard low-dose protocol were: 100 kV,
50 mA,
64x0.625 mm slice collimation; while the ultra-low-dose protocol was set as follows: 80 kV,
50 mA,
64x0.312 mm slice collimation.images were recontructed in axial,
coronal and sagittal view,
at 2 mm thichness (axial and...
Results
All scans were considered to be of adeguate diagnostic image quality.Median score of ethmoid cribrose laminae and ostium-meatali complexes was 4.6.
Regarding radiation exposure,
in both protocols we evaluatedSize and Size-Specific Dose EstimatesSSDE,Computer Tomography Dose IndexCTDIvol andDose LenghtProductDLP.
Results are shown in table 1.
DLP decreases from 171.6 to 77.3 mGy*cm; SSDE decreases from 12.1 to 6.7 mGy while CTDI decreases from 10.9 to 6 mGy.
These results were obtained by changing only kV values.
Radiation exposure was significant smaller in the ultra-low-dose protocol group,...
Conclusion
In a small group of patients,
we demonstrated radiation exposure from low-dose CT can be further reduced by 50% in maxillofacial CT,
without losing diagnostic image quality.
The achievement of this goal,
without compromising diagnostic image quality,
is of paramount importance,
in particular when dealing with young patients.
These results were obtained by changing only kV values.
Due to some patient’s young age this is a fundamental primary endpoint achieved without compromising diagnostic image quality.
References
Low-Dose CT of the Paranasal Sinuses: Minimizing X-Ray Exposure with Spectral Shaping
Eur Radiol (2016) 26:4155–4161