Comparison of different iterative CT reconstruction techniques and filtered back projection for assessment of the medial clavicular epiphysis in forensic age estimation

• Published in: International journal of legal medicine 2020, Vol.134 (1), p.355-361
• Main Authors: Tozakidou, Magdalini, Apine, Ilze, Petersen, Kay U., Weinrich, Julius Matthias, Schindera, Sebastian, Jopp-van Well, Eilin, Püschel, Klaus, Herrmann, Jochen
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Age Determination by Skeleton - methods; Algorithms; Chronology; Clavicle - diagnostic imaging; Computed tomography; Delineation; Epiphyses - diagnostic imaging; Forensic Medicine; Humans; Image enhancement; Image Processing, Computer-Assisted - methods; Image quality; Image reconstruction; Iterative algorithms; Iterative methods; Male; Medical imaging; Medical Law; Medicine; Medicine & Public Health; Noise reduction; Original Article; Osteogenesis; Radiation Dosage; Retrospective Studies; Signal-To-Noise Ratio; Standardization; Tomography, X-Ray Computed - methods; Young Adult
• ISSN: 0937-9827; 1437-1596
• DOI: 10.1007/s00414-019-02214-x

Purpose To assess the impact of iterative reconstruction and filtered back projection (FBP) on image quality in computed tomography (CT)-based forensic age estimation of the medial clavicular epiphysis. Methods and materials CT of the clavicle was performed in 19 patients due to forensic reasons (70 mAs/140 kVp). Raw data were reconstructed with FBP and with an iterative algorithm at level 4 and 6. Clavicular ossification stage was determined by two radiologists in consensus, firstly on FBP reconstructed images and secondly after reviewing all reconstructions including iDose 4 and 6. In addition, the 3 reconstructions were compared regarding artefacts and delineation of the meta-/epiphyseal interface. Quantitative image noise was measured. Results Quantitative noise was lower in iDose 6 reconstructed images than in FBP ( P < 0.042), but not significantly lower between iDose 4 and FBP ( P = 0.127). Side by side comparison revealed lesser qualitative image noise on both iDose reconstructed images than for FBP. The meta-/epiphyseal interface delineation was rated better on both iDose levels than with FBP. In 3 of 19 patients, the clavicular ossification stage was reclassified after iterative reconstructions had been additionally reviewed. Conclusion Using iterative CT reconstruction algorithms, a reduction of image noise and an enhancement of image quality regarding the meta-/epiphyseal clavicular interface can be achieved. The study highlights the importance of image standardization as variation of reconstruction technique has impact on forensic age estimation.