Flat-panel CT arthrography: feasibility study and comparison to multidetector CT arthrography
Roman Guggenberger1, Michael Alexander Fischer, Juerg Hodler
1Department of Radiology, University Hospital Zurich, Zurich, Switzerland. roman.guggenberger@usz.ch
Objectives:
To show the feasibility of flat-panel computed tomography (FPCT) arthrography and quantitatively and qualitatively compare different FPCT protocols with standard multidetector computed tomography (MDCT).
Materials And Methods:
First, a phantom simulating joint space with increasing iodine concentrations was scanned using a standard MDCT and 3 different FPCT protocols. Quantitative analyses were performed by measuring CT numbers of iodine dilutions, radiation dose, and image noise as well as signal-to-noise ratio and contrast-to-noise ratio. Second, FPCT arthrographies of 4 animal joint specimens were performed and analyzed qualitatively by 2 independent readers who evaluated image artifacts, image noise, overall image quality and anatomic depiction of bone, cartilage, and soft tissue. Kappa values were calculated for inter-reader agreement. Pearson's correlation coefficient (r) and Wilcoxon signed-ranks test with Bonferroni corrections for multiple comparisons were used to compare MDCT and FPCT.
Results:
In phantoms, all CT scans showed a linear correlation between increasing iodine concentrations and mean HU values of contrast media and radiation dose, respectively (r = 0.98-0.99, P < 0.01). Dose-length product remained constant for MDCT scans. Signal-to-noise ratio for phantom water linearly decreased in all FPCT scans with increasing iodine concentrations. Contrast-to-noise ratio curves showed reduced slope at iodine concentrations higher than 75 mg/mL. FPCT arthrography after intra-articular administration of 5 to 6 mL of a 25% dilution of iopromide (Ultravist 300 mg/mL, Bayer HealthCare, Berlin, Germany) was successfully performed in all 4 animal joint specimens. Kappa values for inter-reader agreement of qualitative image analyses were 0.62 to 0.91. Image and depiction quality of 20-s FPCT scans were similar or superior compared with standard MDCT (P < 0.005).
Conclusion:
FPCT arthrography is feasible and may allow similar image quality compared with standard MDCT arthrography.
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Description of the Procedures
Computed Tomography (CT) scan:
Computed Tomography (CT) scans use X-ray technology to generate detailed images of bones, organs, and tissues. During the scan, the patient lies on a moving table...
Computed Tomography
The technique was invented in the 1970s and is based on the principle that as X-rays pass through the body, they are absorbed or reflected at different levels. In the technique, a patient lies on a motorized platform while a computerized axial tomography (CAT) scanner rotates...


