Nuklearmedizin - NuclearMedicine, Inhaltsverzeichnis

Nuklearmedizin 2018; 57(04): 153-159
DOI: 10.3413/Nukmed-0953-17-12

Original Article

Georg Thieme Verlag

Image Quality Assessment for Low-Dose-CT in Hybrid SPECT/CT Imaging

Bildqualität-Bewertungsmethode für Niedrigdosis-Computertomographie bei der Hybridbildgebung (SPECT/CT)

Oliver S. Grosser

¹Department of Radiology and Nuclear Medicine, University Hospital Magdeburg, Magdeburg, Germany

,

Juri Ruf

²Department of Nuclear Medicine, Medical Centre, University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany

,

Dennis Kupitz

¹Department of Radiology and Nuclear Medicine, University Hospital Magdeburg, Magdeburg, Germany

,

Damian Czuczwara

¹Department of Radiology and Nuclear Medicine, University Hospital Magdeburg, Magdeburg, Germany

,

David Loewenthal

¹Department of Radiology and Nuclear Medicine, University Hospital Magdeburg, Magdeburg, Germany

,

Markus Thormann

¹Department of Radiology and Nuclear Medicine, University Hospital Magdeburg, Magdeburg, Germany

,

Christian Furth

¹Department of Radiology and Nuclear Medicine, University Hospital Magdeburg, Magdeburg, Germany

³Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Nuclear Medicine, Berlin, Germany

,

Jens Ricke

¹Department of Radiology and Nuclear Medicine, University Hospital Magdeburg, Magdeburg, Germany

⁴Department of Clinical Radiology, Munich University Hospitals, Grosshadern, Ludwig Maximilians University, Munich, Germany

,

Maciej Pech

¹Department of Radiology and Nuclear Medicine, University Hospital Magdeburg, Magdeburg, Germany

,

Michael C. Kreissl

¹Department of Radiology and Nuclear Medicine, University Hospital Magdeburg, Magdeburg, Germany

,

Holger Amthauer

¹Department of Radiology and Nuclear Medicine, University Hospital Magdeburg, Magdeburg, Germany

³Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Nuclear Medicine, Berlin, Germany

› Institutsangaben

Summary

Objectives: Low-dose-computed tomography (LD-CT) is used in nuclear medicine hybrid imaging (e.g., SPECT/CT) for attenuation correction of emission data and anatomical correlation of findings. However, there are currently no standards for image quality (e. g., detectability) comparable to those for diagnostic CT. Therefore, the aim of this explorative study was to evaluate retrospective LDCT data in terms of CT image quality and detectability of anatomical structures. Methods: Two readers blindly scored abdominal LD-CT images (n = 40 patients) in terms of detectability (n = 20 structures/patient), image quality, and readers’ confidence in scoring the image quality for a clinically hybrid imaging protocol. Results were analysed by ANOVA to identify factors (e. g., anatomical structures) that influenced performance scores. The inter-rater agreement was evaluated by determining the chance-corrected Cohen’s Kappa coefficient. Results: Image noise was acceptable for anatomical correlation in 96.1 % of the readings with an almost perfect inter-rater agreement (K_BP = 0.85). A detectability of at least 80 % was observed in 13/20 (K_BP ≥ 0.7) and 90 % in 9/20 (K_BP ≥ 0.85) of the structures analysed by both readers. The confidence of both readers in scoring image quality was at least sufficient in 98.8 % of the examined patients (K_BP = 0.95). Conclusion: Although LD-CT protocols commonly used in hybrid imaging have a poor image quality not suitable for primary CT diagnostics, they enable detection of a variety of anatomical structures. LDCT can therefore also be referenced in the associated reports for anatomical correlation of findings from SPECT imaging.

Keywords

Keywords

SPECT/CT - Low-Dose-CT - Hybrid imaging - Detectability - Image quality

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