Improvement of image quality and dose management in CT fluoroscopy by iterative 3D image reconstruction.
OBJECTIVE
The objective of this study was to assess the influence of an iterative CT reconstruction algorithm (IA), newly available for CT-fluoroscopy (CTF), on image noise, readers' confidence and effective dose compared to filtered back projection (FBP).


METHODS
Data from 165 patients (FBP/IA = 82/74) with CTF in the thorax, abdomen and pelvis were included. Noise was analysed in a large-diameter vessel. The impact of reconstruction and variables (e.g. X-ray tube current I) influencing noise and effective dose were analysed by ANOVA and a pairwise t-test with Bonferroni-Holm correction. Noise and readers' confidence were evaluated by three readers.


RESULTS
Noise was significantly influenced by reconstruction, I, body region and circumference (all p ≤ 0.0002). IA reduced the noise significantly compared to FBP (p = 0.02). The effect varied for body regions and circumferences (p ≤ 0.001). The effective dose was influenced by the reconstruction, body region, interventional procedure and I (all p ≤ 0.02). The inter-rater reliability for noise and readers' confidence was good (W ≥ 0.75, p < 0.0001). Noise and readers' confidence were significantly better in AIDR-3D compared to FBP (p ≤ 0.03). Generally, IA yielded a significant reduction of the median effective dose.


CONCLUSIONS
The CTF reconstruction by IA showed a significant reduction in noise and effective dose while readers' confidence increased.


CONCLUSIONS
• CTF is performed for image guidance in interventional radiology. • Patient exposure was estimated from DLP documented by the CT. • Iterative CT reconstruction is appropriate to reduce image noise in CTF. • Using iterative CT reconstruction, the effective dose was significantly reduced in abdominal interventions.
Department of Radiology and Nuclear Medicine, University Hospital Magdeburg, Leipziger Strasse 44, 39120, Magdeburg, Germany. oliver.grosser@med.ovgu.de.
Oliver S
OS
Grosser
Department of Radiology and Nuclear Medicine, University Hospital Magdeburg, Leipziger Strasse 44, 39120, Magdeburg, Germany.|Institute for Diagnostic and Interventional Radiology, University Hospital Cologne, Cologne, Germany.
Christian
C
Wybranski
Department of Radiology and Nuclear Medicine, University Hospital Magdeburg, Leipziger Strasse 44, 39120, Magdeburg, Germany.
Dennis
D
Kupitz
Department of Radiology and Nuclear Medicine, University Hospital Magdeburg, Leipziger Strasse 44, 39120, Magdeburg, Germany.
Maciej
M
Powerski
Department of Radiology and Nuclear Medicine, University Hospital Magdeburg, Leipziger Strasse 44, 39120, Magdeburg, Germany.
Konrad
K
Mohnike
Department of Radiology and Nuclear Medicine, University Hospital Magdeburg, Leipziger Strasse 44, 39120, Magdeburg, Germany.|Second Department of Radiology, Medical University of Gdansk, Gdansk, Poland.
Maciej
M
Pech
Department of Radiology and Nuclear Medicine, University Hospital Magdeburg, Leipziger Strasse 44, 39120, Magdeburg, Germany.|Department of Nuclear Medicine, Charité, Berlin, Germany.
Holger
H
Amthauer
Department of Radiology and Nuclear Medicine, University Hospital Magdeburg, Leipziger Strasse 44, 39120, Magdeburg, Germany.
Jens
J
Ricke
D000005:Abdomen / Q000000981:diagnostic imaging; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D005260:Female; D005471:Fluoroscopy / Q000379:methods*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010388:Pelvis / Q000000981:diagnostic imaging; D058996:Quality Improvement; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods; D015641:Radiography, Interventional / Q000379:methods; D015203:Reproducibility of Results; D013909:Thorax / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed / Q000379:methods*
CT fluoroscopy; Dose length product; Effective dose; Image noise; Iterative CT reconstruction