Iterative reconstruction in single source dual-energy CT pulmonary angiography: Is it sufficient to achieve a radiation dose as low as state-of-the-art single-energy CTPA?
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Date publication
juillet 2015
Auteurs
Membres identifiés du Cancéropôle Est :
Pr ROY Catherine
Tous les auteurs :
Ohana M, Labani A, Jeung MY, Ghannudi SE, Gaertner S, Roy C
Lien Pubmed
Résumé
OBJECTIVE: Dual-energy (DE) brings numerous significant improvements in pulmonary CT angiography (CTPA), but is associated with a 15-50% increase in radiation dose that prevents its widespread use. We hypothesize that thanks to iterative reconstruction (IR), single source DE-CTPA acquired at the same radiation dose that a single-energy examination will maintain an equivalent quantitative and qualitative image quality, allowing a more extensive use of the DE technique in the clinical routine. MATERIAL AND METHODS: Fifty patients (58% men, mean age 64.8yo+/-16.2, mean BMI 25.6+/-4.5) were prospectively included and underwent single source DE-CTPA with acquisition parameters (275mA fixed tube current, 50% IR) tweaked to target a radiation dose similar to a 100kV single-energy CTPA (SE-CTPA), i.e., a DLP of 260mGycm. Thirty patients (47% men, 64.4yo+/-18.6, BMI 26.2+/-4.6) from a previous prospective study on DE-CTPA (375mA fixed tube current, reconstruction with filtered-back projection) were used as the reference group. Thirty-five consecutive patients (57% men, 65.8yo+/-15.5, BMI 25.7+/-4.4) who underwent SE-CTPA on the same scanner (automated tube current modulation, 50% IR) served as a comparison. Subjective image quality was scored by two radiologists using a 5-level scale and compared with a Kruskal-Wallis nonparametric test. Density measurements on the 65keV monochromatic reconstructions were used to calculate signal-to-noise (SNR) and contrast-to-noise (CNR) ratios that were compared using a Student's t test. Correlations between image quality, SNR, CNR and BMI were sought using a Pearson's test. p/=3). In comparison with the reference DE-CTPA and the SE-CTPA protocols, the DE-IR group exhibited a non-inferior image quality (p=0.95 and p=0.21, respectively) and a significantly lower mean image noise (p
Référence
Eur J Radiol. 2015 Jul 17. pii: S0720-048X(15)30051-6