TY  - JOUR
IS  - 12
KW  - Alignment correction
KW  -  Cold-water corals
KW  -  Phantoms (imaging)
KW  -  Sediment core
KW  -  Tomography (x-ray computed)
UR  - https://archiv.ub.uni-heidelberg.de/volltextserver/26189/
CY  - Cham
PB  - Springer International Publishing
N2  - Background: In computed tomography (CT) quality assurance, alignment of image quality phantoms is crucial for quantitative and reproducible evaluation and may be improved by alignment correction. Our goal was to develop an alignment correction algorithm to facilitate geological sampling of sediment cores taken from a cold-water coral mount.

Methods: An alignment correction algorithm was developed and tested with a CT acquisition at 120?kVp and 150?mAs of an image quality phantom. Random translation (maximum 15?mm) and rotation (maximum 2.86°) were applied and ground-truth was compared to parameters determined by alignment correction. Furthermore, mean densities were evaluated in four regions of interest (ROIs) placed in the phantom low-contrast section, comparing values before and after correction to ground truth. This process was repeated 1000 times. After validation, alignment correction was applied to CT acquisitions (140 kVp, 570 mAs) of sediment core sections up to 1?m in length, and sagittal reconstructions were calculated for sampling planning.

Results: In the phantom, average absolute differences between applied and detected parameters after alignment correction were 0.01?±?0.06?mm (mean?±?standard deviation) along the x-axis, 0.11?±?0.08?mm along the y-axis, 0.15?±?0.07° around the x-axis, and 0.02?±?0.02° around the y-axis, respectively. For ROI analysis, differences in densities were 63.12?±?30.57, 31.38?±?32.10, 18.27?±?35.57, and 9.59?±?26.37 HU before alignment correction and 1.22?±?1.40, 0.76?±?0.9, 0.45?±?0.86, and 0.36?±?0.48 HU after alignment correction, respectively. For sediment core segments, average absolute detected parameters were 3.93?±?2.89?mm, 7.21?±?2.37?mm, 0.37?±?0.33°, and 0.21?±?0.22°, respectively.

Conclusions: The alignment correction algorithm was successfully evaluated in the phantom and allowed a correct alignment of sediment core segments, thus aiding in sampling planning. Application to other tasks, like image quality analysis, seems possible.
AV  - public
ID  - heidok26189
SN  - 2509-9280
SP  - 1
TI  - Experimental application of an automated alignment correction algorithm for geological CT imaging: phantom study and application to sediment cores from cold-water coral mounds
VL  - 3
JF  - European Radiology Experimental
EP  - 8
Y1  - 2019///
A1  - Skornitzke, Stephan
A1  - Raddatz, Jacek
A1  - Bahr, André
A1  - Pahn, Gregor
A1  - Kauczor, Hans-Ulrich
A1  - Stiller, Wolfram
ER  -