Iterative reconstructed ultra high pitch CT pulmonary angiography with cardiac bowtie-shaped filter in the acute setting: Effect on dose and image quality
| Autor: | Savvas Nicolaou, Teresa Liang, Masoud Yousefi, Karl Krzymyk, John R. Mayo, Steven J. Co |
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| Rok vydání: | 2013 |
| Předmět: |
Adult
Male Image quality Iterative reconstruction Pulmonary Artery Radiation Dosage Sensitivity and Specificity Effective dose (radiation) Background noise Prevalence High pitch Humans Medicine Radiology Nuclear Medicine and imaging Radiometry Aged Aged 80 and over British Columbia Radon transform business.industry Attenuation Angiography Reproducibility of Results General Medicine Middle Aged medicine.disease Pulmonary embolism Radiographic Image Enhancement Radiographic Image Interpretation Computer-Assisted Female Pulmonary Embolism Tomography X-Ray Computed business Nuclear medicine |
| Zdroj: | European Journal of Radiology. 82:1571-1576 |
| ISSN: | 0720-048X |
| DOI: | 10.1016/j.ejrad.2013.04.043 |
| Popis: | To evaluate the effect of a cardiac bowtie-shaped filter in an ultra high pitch CTPA protocol at 100 kV on image quality and radiation dose.Retrospective study of 100 patients referred for CTPA. 50 patients scanned with a standard 100 kV protocol at pitch 2.8 (Protocol A) and 50 patients scanned with a 100 kV protocol at pitch 3.2 with a cardiac bowtie-shaped filter (Protocol B). All other scanning parameters kept constant. Images from both groups reconstructed with filtered back projection and iterative reconstruction. Central pulmonary vessel attenuation and background noise were quantitatively measured and signal-to-noise (SNR) and contrast-to-noise (CNR) were calculated. Two radiologists performed qualitative assessment grading visualization of the pulmonary vasculature and noise level. CTDIvol and DLP were recorded and effective dose was calculated.CTDIvol, DLP and effective dose were significantly (p0.0001) lower in Protocol B (2.3 ± 0.5 mGy, 78.4 ± 16.5 mGycm, 1.4 ± 0.3 mSy, respectively) compared to Protocol A (4.3 ± 0.5 mGy, 152.0 ± 19.6 mGycm, 2.7 ± 0.3 mSy, respectively). Protocol B had significantly (p0.0001) higher noise than Protocol A (23.8 ± 6.9 HU vs 36.8 ± 7.3 HU) and lower SNR (11.8 ± 3.7 HU vs 19.2 ± 8.1 HU) and CNR (10.3 ± 3.7 HU vs 24.9 ± 13.4 HU) but there was no significant difference in the subjective visualization of the pulmonary vasculature (p=0.63). Furthermore, iterative reconstruction significantly (p0.0001) improves image noise (29.4 ± 5.5 HU from 36.8 ± 7.3 HU).The addition of a cardiac bowtie-shaped filter with an ultra high pitch CTPA protocol at 100 kV resulted in a 48% dose reduction without significantly affecting diagnostic image quality. In addition, the use of iterative reconstruction significantly improves image quality by reducing noise permitting the possibility for further dose reduction strategies. |
| Databáze: | OpenAIRE |
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