Image quality of iterative reconstruction in cranial CT imaging: comparison of model-based iterative reconstruction (MBIR) and adaptive statistical iterative reconstruction (ASiR)

• Published in: European radiology Vol. 25; no. 1; pp. 140 - 146
• Main Authors: Notohamiprodjo, S., Deak, Z., Meurer, F., Maertz, F., Mueck, F. G., Geyer, L. L., Wirth, S.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.01.2015; Springer Nature B.V
• Subjects: Adult; Aged; Aged, 80 and over; Algorithms; Brain Diseases - diagnostic imaging; Computed Tomography; Contrast Media; Diagnostic Radiology; Emergency medical care; Female; Hematoma; Humans; Imaging; Internal Medicine; Interventional Radiology; Male; Medicine; Medicine & Public Health; Middle Aged; Models, Theoretical; Neuroradiology; Patients; Prospective Studies; Radiation Dosage; Radiographic Image Interpretation, Computer-Assisted - methods; Radiology; Review boards; Signal-To-Noise Ratio; Tomography; Tomography, X-Ray Computed - methods; Trauma; Ultrasound; Young Adult; Artefacts; Depiction; Image quality enhancement; Iterative reconstruction; Cranial CT
• ISSN: 0938-7994; 1432-1084
• DOI: 10.1007/s00330-014-3374-8

Objectives The purpose of this study was to compare cranial CT (CCT) image quality (IQ) of the MBIR algorithm with standard iterative reconstruction (ASiR). Methods In this institutional review board (IRB)-approved study, raw data sets of 100 unenhanced CCT examinations (120 kV, 50–260 mAs, 20 mm collimation, 0.984 pitch) were reconstructed with both ASiR and MBIR. Signal-to-noise (SNR) and contrast-to-noise (CNR) were calculated from attenuation values measured in caudate nucleus, frontal white matter, anterior ventricle horn, fourth ventricle, and pons. Two radiologists, who were blinded to the reconstruction algorithms, evaluated anonymized multiplanar reformations of 2.5 mm with respect to depiction of different parenchymal structures and impact of artefacts on IQ with a five-point scale (0: unacceptable, 1: less than average, 2: average, 3: above average, 4: excellent). Results MBIR decreased artefacts more effectively than ASiR ( p  < 0.01). The median depiction score for MBIR was 3, whereas the median value for ASiR was 2 ( p  < 0.01). SNR and CNR were significantly higher in MBIR than ASiR ( p  < 0.01). Conclusions MBIR showed significant improvement of IQ parameters compared to ASiR. As CCT is an examination that is frequently required, the use of MBIR may allow for substantial reduction of radiation exposure caused by medical diagnostics. Key Points • Model-Based iterative reconstruction (MBIR) effectively decreased artefacts in cranial CT . • MBIR reconstructed images were rated with significantly higher scores for image quality . • Model-Based iterative reconstruction may allow reduced-dose diagnostic examination protocols .