Browsing by Author "Buissink, C."
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- Aneurysm clips in brain imaging using CBCT: the development of a phantom and the influence of kvp and metal suppression on image qualityPublication . Harsaker, V.; Buttazzoni, M.; Cardoso, Ângela; Knijff, A.; Mookrey, T.; Safai, O.; Buissink, C.Purpose: For this study, a phantom was produced to evaluate the influence of kVp and metal suppression on the image quality in CBCT brain imaging containing titanium aneurysm clips. Method and material: A head phantom was constructed comprising of a pig skull with its neurocranium filled with butter to simulate the human brain. CBCT was used to scan the phantom. Three different aneurysm clips were used (two in different sizes and one with a different size and shape). Acquisitions were made using different values of kVp (80, 84, 88, 92, 96). Each acquisition was reconstructed in every anatomical plane, with and without metal suppression. For post-processing, ImageJ was used to place ROIs in specific areas. Standard deviation, representing noise; data was analysed using T-tests. Results: The phantom was suitable for aneurysm implant placement. The noise is most severe in the axial plane (p<0.05) and the larger clips produced more noise. Metal suppression resulted in a significant reduction of noise in all three planes (p<0.05). Compared to metal suppression, the reduction in noise with an increase in kVp is minimal. Conclusion: Metal suppression is effective in reducing metal artefacts in CBCT brain imaging.
- Guest editorial: OPTIMAX 2013Publication . Lança, Luís; Buissink, C.; Jorge, José; Sanderud, Audun; Hogg, PeterIn 2012 we were awarded an Erasmus Intensive Programme grant to facilitate OPTIMAX 2013, a three week duration residential summer school held within the UK during August 2013. The summer school helped to further develop student radiographer skills in optimising x-radiation dose and image quality. With a major emphasis on visual techniques to determine image quality, lesion visibility, lesion detection performance and physical measures of image quality (eg signal to noise ratio (SNR)) we conducted controlled laboratory experiments on phantoms using Computed Radiography, CT and Full Field Digital Mammography. Mathematical modelling was used for radiation dose estimation. Sixty seven people from 5 European countries participated. This included 49 PhD, MSc and BSc students. Discipline areas included radiography, physics, biomedical science and nuclear medicine.
- The influence of experience and training in a group of novice observers: a jackknife alternative free-response receiver operating characteristic analysisPublication . Buissink, C.; Thompson, John D.; Voet, M.; Sanderud, Audun; Kamping, L. V.; Savary, L.; Mughal, M.; Rocha, C. S.; Hart, G. E.; Parreiral, R.; Martin, G.; Hogg, PeterPurpose - The study evaluates the pre- and post-training lesion localisation ability of a group of novice observers. Parallels are drawn with the performance of inexperienced radiographers taking part in preliminary clinical evaluation (PCE) and ‘red-dot’ systems, operating within radiography practice. Materials and methods - Thirty-four novice observers searched 92 images for simulated lesions. Pre-training and post-training evaluations were completed following the free-response the receiver operating characteristic (FROC) method. Training consisted of observer performance methodology, the characteristics of the simulated lesions and information on lesion frequency. Jackknife alternative FROC (JAFROC) and highest rating inferred ROC analyses were performed to evaluate performance difference on lesion-based and case-based decisions. The significance level of the test was set at 0.05 to control the probability of Type I error. Results - JAFROC analysis (F(3,33) = 26.34, p < 0.0001) and highest-rating inferred ROC analysis (F(3,33) = 10.65, p = 0.0026) revealed a statistically significant difference in lesion detection performance. The JAFROC figure-of-merit was 0.563 (95% CI 0.512,0.614) pre-training and 0.677 (95% CI 0.639,0.715) post-training. Highest rating inferred ROC figure-of-merit was 0.728 (95% CI 0.701,0.755) pre-training and 0.772 (95% CI 0.750,0.793) post-training. Conclusions - This study has demonstrated that novice observer performance can improve significantly. This study design may have relevance in the assessment of inexperienced radiographers taking part in PCE or commenting scheme for trauma.