title: EFFECT OF RADIATION DOSE LEVEL ON ACCURACY AND PRECISION OF MANUAL SIZE MEASUREMENTS IN CHEST TOMOSYNTHESIS EVALUATED USING SIMULATED PULMONARY NODULES.
abstract: The aim of the present study was to investigate the dependency of the accuracy and precision of nodule diameter measurements on the radiation dose level in chest tomosynthesis. Artificial ellipsoid-shaped nodules with known dimensions were inserted in clinical chest tomosynthesis images. Noise was added to the images in order to simulate radiation dose levels corresponding to effective doses for a standard-sized patient of 0.06 and 0.04 mSv. These levels were compared with the original dose level, corresponding to an effective dose of 0.12 mSv for a standard-sized patient. Four thoracic radiologists measured the longest diameter of the nodules. The study was restricted to nodules located in high-dose areas of the tomosynthesis projection radiographs. A significant decrease of the measurement accuracy and intraobserver variability was seen for the lowest dose level for a subset of the observers. No significant effect of dose level on the interobserver variability was found. The number of non-measurable small nodules (≤5 mm) was higher for the two lowest dose levels compared with the original dose level. In conclusion, for pulmonary nodules at positions in the lung corresponding to locations in high-dose areas of the projection radiographs, using a radiation dose level resulting in an effective dose of 0.06 mSv to a standard-sized patient may be possible in chest tomosynthesis without affecting the accuracy and precision of nodule diameter measurements to any large extent. However, an increasing number of non-measurable small nodules (≤5 mm) with decreasing radiation dose may raise some concerns regarding an applied general dose reduction for chest tomosynthesis examinations in the clinical praxis.
authors.affiliation: Department of Radiation Physics, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden christina.e.soderman@vgregion.se.
authors.forename: Christina
authors.initials: C
authors.lastname: Söderman
authors.affiliation: Department of Radiology, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden Department of Radiology, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden.
authors.forename: Åse Allansdotter
authors.initials: ÅA
authors.lastname: Johnsson
authors.affiliation: Department of Radiology, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden Department of Radiology, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden.
authors.forename: Jenny
authors.initials: J
authors.lastname: Vikgren
authors.affiliation: Department of Radiology, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden Department of Radiology, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden.
authors.forename: Rauni Rossi
authors.initials: RR
authors.lastname: Norrlund
authors.affiliation: Department of Radiology, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden Department of Radiology, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden.
authors.forename: David
authors.initials: D
authors.lastname: Molnar
authors.affiliation: Department of Radiation Physics, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden.
authors.forename: Angelica
authors.initials: A
authors.lastname: Svalkvist
authors.affiliation: Department of Radiation Physics, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden.
authors.forename: Lars Gunnar
authors.initials: LG
authors.lastname: Månsson
authors.affiliation: Department of Radiation Physics, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden.
authors.forename: Magnus
authors.initials: M
authors.lastname: Båth
mesh_terms: D003198:Computer Simulation; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging; D015588:Observer Variation; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D013902:Radiography, Thoracic / Q000379:methods*; D011871:Radiology / Q000379:methods; D015203:Reproducibility of Results; D003074:Solitary Pulmonary Nodule / Q000000981:diagnostic imaging*; D013909:Thorax / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed / Q000379:methods*