Advantage of appropriate K-edge filters for one-shot dual-energy subtraction sialography.
OBJECTIVE
To determine the optimal added filtration for use for one-shot dual energy subtraction sialography.


METHODS
Test phantoms composed of bone and soft tissue materials were imaged with computed radiography using one-shot dual energy subtraction radiography. Eight different additional filter materials were compared with gadolinium contrast. Two numerical measures (absorption ratio and separation index) were used to compare the subtracted images obtained with the various filter/contrast combinations. The K-edge spectra were measured for each filter/contrast combination. A preliminary comparison of a 1.5 M iodine contrast medium with a 1.5 M gadolinium was performed using canine sialography.


RESULTS
The gadolinium contrast/samarium filter combination had a larger separation index (P < 0.05). The same combination yielded better sialograms than iodine contrast.


CONCLUSIONS
Samarium filter has an optimal k-edge for one-shot dual-energy sialography with gadolinium contrast.
Department of Oral and Maxillofacial Radiology, Kanagawa Dental College, Japan.
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Kobayashi
D000818:Animals; D003287:Contrast Media; D004285:Dogs; D005374:Filtration / Q000295:instrumentation; D005682:Gadolinium; D007091:Image Processing, Computer-Assisted; D019047:Phantoms, Imaging; D011856:Radiographic Image Enhancement; D015900:Radiography, Dual-Energy Scanned Projection / Q000379:methods*; D012493:Samarium; D012796:Sialography / Q000295:instrumentation* / Q000379:methods*
D003287:Contrast Media; D012493:Samarium; D005682:Gadolinium