Impact of iterative reconstructions on image quality and detectability of focal liver lesions in low-energy monochromatic images

Autor: Jean Paul Beregi, Djamel Dabli, Aymeric Hamard, J.M. Teissier, Joël Greffier, J. Frandon, Hugo Pasquier
Přispěvatelé: Centre Hospitalier Universitaire de Nîmes (CHU Nîmes), Aide à la Décision pour une Médecine Personnalisé - Laboratoire de Biostatistique, Epidémiologie et Recherche Clinique - EA 2415 (AIDMP), Université Montpellier 1 (UM1)-Université de Montpellier (UM), Institut de Cancérologie du GARD ICG - CHU Nîmes (Instit Cancéro - GARD), General Electric Medical Systems [Buc] (GE Healthcare), General Electric Medical Systems
Jazyk: angličtina
Rok vydání: 2020
Předmět:
MESH: Radiation Dosage
Carcinoma
Hepatocellular
Image quality
Multidetector Computed tomography
Biophysics
General Physics and Astronomy
[SDV.CAN]Life Sciences [q-bio]/Cancer
Iterative reconstruction
Radiation Dosage
Dose level
MESH: Carcinoma
Hepatocellular / diagnostic imaging
Imaging phantom
030218 nuclear medicine & medical imaging
03 medical and health sciences
0302 clinical medicine
Low energy
[INFO.INFO-IM]Computer Science [cs]/Medical Imaging
Humans
Radiology
Nuclear Medicine and imaging
Image resolution
Physics
MESH: Humans
Phantoms
Imaging
business.industry
Liver Neoplasms
General Medicine
MESH: Liver / diagnostic imaging
MESH: Tomography
X-Ray Computed / methods
MESH: Liver Neoplasms / diagnostic imaging
MESH: Phantoms
Imaging
Liver
Dual-energy
030220 oncology & carcinogenesis
Task-based image quality assessment
Radiographic Image Interpretation
Computer-Assisted
MESH: Radiographic Image Interpretation
Computer-Assisted / methods
Spatial frequency
Monochromatic color
Tomography
X-Ray Computed
Nuclear medicine
business
Zdroj: Physica Medica
Physica Medica, Elsevier, 2020, 77, pp.36-42. ⟨10.1016/j.ejmp.2020.07.024⟩
ISSN: 1120-1797
DOI: 10.1016/j.ejmp.2020.07.024⟩
Popis: International audience; Purpose: To assess the impact of iterative reconstructions on image quality and detectability of focal liver lesions in low-energy monochromatic images from a Fast kV-Switching Dual Energy CT (KVSCT) platform.Methods: Acquisitions on an image-quality phantom were performed using a KVSCT for three dose levels (CTDIvol:12.72/10.76/8.79 mGy). Raw data were reconstructed for five energy levels (40/50/60/70/80 keV) using Filtered Back Projection (FBP) and four levels of ASIR (ASIR30/ASIR50/ASIR70/ASIR100). Noise power spectrum (NPS) and task-based transfer function (TTF) were measured before computing a Detectability index (d') to model the detection task of liver metastasis (LM) and hepatocellular carcinoma (HCC) as function of keV.Results: From 40 to 70 keV, noise-magnitude was reduced on average by -68% ± 1% with FBP; -61% ± 3% with ASIR50 and -52% ± 6% with ASIR100. The mean spatial frequency of the NPS decreased when the energy level decreased and the iterative level increased. TTF values at 50% decreased as the energy level increased and as the percentage of ASIR increased. The detectability of both lesions increased with increasing dose level and percentage of ASIR. For the LM, d' peaked at 70 keV for all reconstruction types, except for ASIR70 at 12.72 mGy and ASIR100, where d' peaked at 50 keV. For HCC, d' peaked at 60 keV for FBP and ASIR30 but peaked at 50 keV for ASIR50, ASIR70 and ASIR100.Conclusions: Using percentage of ASIR above 50% at low-energy monochromatic images could limit the increase of noise-magnitude, benefit from spatial resolution improvement and hence enhance detectability of subtle low contrast focal liver lesions such as HCC.
Databáze: OpenAIRE
Externí odkaz: