PURPOSE: This study aimed to evaluate image quality of ultra-low dose chest computed tomography using 6 iterative reconstruction (IR) algorithms. METHOD: A lung phantom was scanned on 4 computed tomography scanners using fixed tube voltages and the lowest mAs available on each scanner, resulting in dose levels of 0.1 to 0.2 mGy (80 kVp) and 0.3 to 1 mGy (140 kVp) volume CT dose index (CTDIvol). Images were reconstructed with IR available on the scanners. Image noise, signal-to-noise ratios, contrast-to-noise ratios, uniformity, and noise power spectrum (NPS) were assessed for evaluation of image quality. RESULTS: Image quality parameters increased with increasing dose for all algorithms. At constant dose levels, model-based techniques improved the contrast-to-noise ratio of lesions more than the statistical algorithms. All algorithms tested at 0.1 mGy showed lower NPS peak frequencies compared with 0.39 mGy. In contrast to the statistical techniques, model-based algorithms showed lower NPS peak frequencies at the lowest doses, indicating a coarser and blotchier noise texture. CONCLUSION: This study shows the importance of evaluating IR when introduced clinically.
PURPOSE: This study aimed to evaluate image quality of ultra-low dose chest computed tomography using 6 iterative reconstruction (IR) algorithms. METHOD: A lung phantom was scanned on 4 computed tomography scanners using fixed tube voltages and the lowest mAs available on each scanner, resulting in dose levels of 0.1 to 0.2 mGy (80 kVp) and 0.3 to 1 mGy (140 kVp) volume CT dose index (CTDIvol). Images were reconstructed with IR available on the scanners. Image noise, signal-to-noise ratios, contrast-to-noise ratios, uniformity, and noise power spectrum (NPS) were assessed for evaluation of image quality. RESULTS: Image quality parameters increased with increasing dose for all algorithms. At constant dose levels, model-based techniques improved the contrast-to-noise ratio of lesions more than the statistical algorithms. All algorithms tested at 0.1 mGy showed lower NPS peak frequencies compared with 0.39 mGy. In contrast to the statistical techniques, model-based algorithms showed lower NPS peak frequencies at the lowest doses, indicating a coarser and blotchier noise texture. CONCLUSION: This study shows the importance of evaluating IR when introduced clinically.
Authors: Camilla Risoli; Marco Nicolò; Davide Colombi; Marco Moia; Fausto Rapacioli; Pietro Anselmi; Emanuele Michieletti; Roberta Ambrosini; Marco Di Terlizzi; Luigi Grazioli; Cristian Colmo; Angelo Di Naro; Matteo Pio Natale; Alessandro Tombolesi; Altin Adraman; Domenico Tuttolomondo; Cosimo Costantino; Elisa Vetti; Chiara Martini Journal: Diagnostics (Basel) Date: 2022-06-20
Authors: Johannes Clemens Godt; Cathrine K Johansen; Anne Catrine T Martinsen; Anselm Schulz; Helga M Brøgger; Kristin Jensen; Arne Stray-Pedersen; Johann Baptist Dormagen Journal: Acta Radiol Open Date: 2021-11-18
Authors: Marian S Solbak; Mette K Henning; Andrew England; Anne C Martinsen; Trond M Aaløkken; Safora Johansen Journal: Eur Radiol Exp Date: 2020-09-11