Flat-panel-detector-based volumetric CT: performance evaluation of imaging for skeletal structures of small animals in comparison to multislice CT.
OBJECTIVE
The aim of this study was to compare the image performance of silicon-based flat-panel-detector-based volumetric computed tomography (fpVCT) to multislice spiral computed tomography (MSCT) for the visualization and detail detectability of skeletal structures in rodents of different development stages.


METHODS
Rodents of different development stages were imaged with fpVCT (GE prototype with circular gantry with two 1024 x 1024, 200-microm pixel size, amorphous silicon/Cesium lodid (Csl) flat-panel detector) and eight-slice MSCT (LightSpeed Ultra). Imaging parameters (80 kVp, 100 mA) and the position of the rodents were identical in both techniques. Image quality, detail detectability, and contour of skeletal structures were judged by two observers in consensus using a 4-point scale (1 = unsatisfactory...4 = good). Findings were displayed and evaluated in axial slices, multiplanar reconstructions (MPR), maximum intensity projections (MIP) and volume rendering technique (VRT) in both modalities. Mean and standard of error of mean were calculated.


RESULTS
In axial slices, visualization and detail detectability of very subtle skeletal structures, e.g., the basis of the skull was better in fpVCT than in MSCT (4 vs. 2 points). The MPRs of fpVCT showed less artifacts and more details than those of the MSCT. The MIPs and VRTs of the fpVCT demonstrated best image quality in all rodents of different development stages, whereas MSCT showed significant artifacts.


CONCLUSIONS
fpVCT outperformed MSCT in imaging of small rodents. Due to the truly isotropic volume data set with high spatial resolution, fpVCT is a powerful tool in evaluating detailed skeletal structures.
Obenauer
Silvia
S
Department of Radiology, Georg-August-University, Robert-Koch-Str. 40, 37099 Gottingen, Germany. soben@med.uni-goettingen.de
Dullin
Christian
C
Alves
Frauke
F
Missbach-Guentner
Jeannine
J
Grabbe
Eckhardt
E
Heuser
Markus
M
D019412:Anatomy, Cross-Sectional / Q000295:instrumentation / Q000379:methods; D000818:Animals; D001842:Bone and Bones / Q000000981:diagnostic imaging*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D021621:Imaging, Three-Dimensional / Q000295:instrumentation* / Q000379:methods / Q000662:veterinary; D051379:Mice; D011856:Radiographic Image Enhancement / Q000295:instrumentation* / Q000379:methods; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000295:instrumentation* / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000295:instrumentation* / Q000379:methods / Q000662:veterinary; D051598:Whole Body Imaging / Q000295:instrumentation* / Q000379:methods / Q000662:veterinary; D014963:X-Ray Intensifying Screens