1. Digital tomosynthesis and ground glass nodules: Optimization of acquisition protocol. A phantom study
- Author
-
Emilio Quaia, Cristina Marrocchio, Alessandro Marco Bozzato, Elisa Baratella, A. Di Giusto, C. Natali, Maria Assunta Cova, Baratella, E., Bozzato, A. M., Marrocchio, C., Di Giusto, A., Natali, C., Quaia, E., and Cova, M. A.
- Subjects
Phantom ,Hilum (biology) ,Digital tomosynthesis ,Ground-glass opacities ,Sensitivity and Specificity ,Imaging phantom ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,business.industry ,Phantoms, Imaging ,Nodule (medicine) ,Tomosynthesis ,Acquisition Protocol ,Apex (geometry) ,Digital tomosynthesi ,Ground-glass opacitie ,Radiographic Image Enhancement ,Visual score ,030220 oncology & carcinogenesis ,Radiography, Thoracic ,medicine.symptom ,business ,Nuclear medicine ,Dose rate ,Tomography, X-Ray Computed - Abstract
Introduction Ground-glass nodules may be the expression of benign conditions, pre-invasive lesions or malignancies. The aim of our study was to evaluate the capability of chest digital tomosynthesis (DTS) in detecting pulmonary ground-glass opacities (GGOs). Methods An anthropomorphic chest phantom and synthetic nodules were used to simulate pulmonary ground-glass nodules. The nodules were positioned in 3 different regions (apex, hilum and basal); then the phantom was scanned by multi-detector CT (MDCT) and DTS. For each set (nodule-free phantom, nodule in apical zone, nodule in hilar zone, nodule in basal zone) seven different scans (n = 28) were performed varying the following technical parameters: Cu-filter (0.1–0.3 mm), dose rateo (10–25) and X-ray tube voltage (105–125 kVp). Two radiologists in consensus evaluated the DTS images and provided in agreement a visual score: 1 for unidentifiable nodules, 2 for poorly identifiable nodules, 3 for nodules identifiable with fair certainty, 4 for nodules identifiable with absolute certainty. Results Increasing the dose rateo from 10 to 15, GGOs located in the apex and in the basal zone were better identified (from a score = 2 to a score = 3). GGOs located in the hilar zone were not visible even with a higher dose rate. Intermediate density GGOs had a good visibility score (score = 3) and it did not improve by varying technical parameters. A progressive increase of voltage (from 105 kVp to 125 kVp) did not provide a better nodule visibility. Conclusion DTS with optimized technical parameters can identify GGOs, in particular those with a diameter greater than 10 mm. Implications for practice DTS could have a role in the follow-up of patients with known GGOs identified in lung apex or base region.
- Published
- 2020