Aims and objectives
Chest tomosynthesis (CTS) is a diagnostic examination where several projection images of the chest are collected from different angles over a limited angular range to reconstruct section images of the patient [1].
Compared to conventional chest radiography (CXR),
CTS provides improved diagnostic information (Fig. 1) and has shown to improve detection of pulmonary nodules [2].
As tomosynthesis is performed with the same imaging system as CXR,
the financial cost is much lower and the patient throughput higher than for a corresponding computed tomography examination [3,...
Methods and materials
Image collection: Twenty-four chest tomosynthesis examinations of patients without pulmonary lesions wereincluded in this retrospective study.
The Regional Ethical Review Board approved this study and all participants gave written informed consent.
The CTS system used was a modified digital chest radiographic system.
During the image collection the x-ray tube performed a vertical motion around the standard orthogonal posteroanterior (PA) projection.
Sixty low-dose projection images were collected in the angular interval of ±15°using a tube voltage of 120 kV with 3 mm Al + 0.1 mm...
Results
Fig. 4 shows an example of a chest tomosynthesis section image before (original dose) and after simulated dose reduction (50% of original dose).
The perceived reproduction was statistically significantly lower for all anatomical structures in the dose reduced images than in the original dose images (AUCVGC<0.5 for each criterion).
The AUCVGC for each quality criterion at the 50% dose level,
using the original dose as reference,
is presented in Fig. 5 .
In the central region of the lung,
the reproduction of trachea,
carina and...
Conclusion
The results of this study indicate that the reproduction of structures of interest in a chest tomosynthesis examination is significantly reduced at a dose level corresponding to 50% of the original dose.
The fact that the reproduction of the central structures in mediastinum (trachea,
carina and main bronchi) and the retrocardiac part of aorta descendens was most affected by the dose reduction may be due to the presence of high density structures in close proximity,
which causes a high level of noise in the central...
Personal information
M.Mirzai,
MSc
Department of Medical Physics and Biomedical Engineering,
Sahlgrenska University Hospital,
Gothenburg,
Sweden
Department of Radiation Physics,
Institute of Clinical Sciences,
The Sahlgrenska Academy at University of Gothenburg,
Gothenburg,
Sweden
Phone: +46739560707
E-mail:
[email protected]
Address: Sahlgrenska University Hospital,
Gula straket 2B,
SE-413 45 Gothenburg Sweden
References
1. Dobbins JT,
3rd,
McAdams HP.
Chest tomosynthesis: technical principles and clinical update.
European journal of radiology.
2009;72(2):244-51.
2. Vikgren J,
Zachrisson S,
Svalkvist A,
Johnsson Ã…A,
Boijsen M,
Flinck A,
et al.
Comparison of chest tomosynthesis and chest radiography for detection of pulmonary nodules: human observer study of clinical cases.
Radiology.
2008;249(3):1034-41.
3. Quaia E,
Baratella E,
Cioffi V,
Bregant P,
Cernic S,
Cuttin R,
et al.
The value of digital tomosynthesis in the diagnosis of suspected pulmonary lesions on chest radiography: analysis of...