Evaluation of automatic image quality assessment in chest CT - A human cadaver study.
PURPOSE
The evaluation of clinical image quality (IQ) is important to optimize CT protocols and to keep patient doses as low as reasonably achievable. Considering the significant amount of effort needed for human observer studies, automatic IQ tools are a promising alternative. The purpose of this study was to evaluate automatic IQ assessment in chest CT using Thiel embalmed cadavers.


METHODS
Chest CT's of Thiel embalmed cadavers were acquired at different exposures. Clinical IQ was determined by performing a visual grading analysis. Physical-technical IQ (noise, contrast-to-noise and contrast-detail) was assessed in a Catphan phantom. Soft and sharp reconstructions were made with filtered back projection and two strengths of iterative reconstruction. In addition to the classical IQ metrics, an automatic algorithm was used to calculate image quality scores (IQs). To be able to compare datasets reconstructed with different kernels, the IQs values were normalized.


RESULTS
Good correlations were found between IQs and the measured physical-technical image quality: noise (ρ=-1.00), contrast-to-noise (ρ=1.00) and contrast-detail (ρ=0.96). The correlation coefficients between IQs and the observed clinical image quality of soft and sharp reconstructions were 0.88 and 0.93, respectively.


CONCLUSIONS
The automatic scoring algorithm is a promising tool for the evaluation of thoracic CT scans in daily clinical practice. It allows monitoring of the image quality of a chest protocol over time, without human intervention. Different reconstruction kernels can be compared after normalization of the IQs.
['Franck|Caro|C|', 'De Crop|An|A|', 'De Roo|Bieke|B|', 'Smeets|Peter|P|', 'Vergauwen|Merel|M|', 'Dewaele|Tom|T|', 'Van Borsel|Mathias|M|', 'Achten|Eric|E|', 'Van Hoof|Tom|T|', 'Bacher|Klaus|K|']
D001331:Automation D002102:Cadaver D006801:Humans D019047:Phantoms, Imaging D011785:Quality Assurance, Health Care D011829:Radiation Dosage D013902:Radiography, Thoracic D059629:Signal-To-Noise Ratio D014057:Tomography, X-Ray Computed
Image quality Chest CT Human cadaver study Automatic IQ assessment