Construction of a copper stepwedge with aluminum equivalent mean gray values.
OBJECTIVE
To produce a copper (Cu) stepwedge with aluminum (Al) equivalent mean gray values (MGV).


METHODS
The thicknesses of Cu steps that were equivalent to those of the Al were formulated using the X-ray attenuation properties of the materials. The Al and fabricated Cu stepwedges were radiographed, but the MGVs of the Cu stepwedge were mismatching to those of the Al. Using a mathematical function to adjust the pixel MGV of Cu stepwedge to those of the Al, new Cu stepwedges were created. In vitro iterations were performed until best approximation to Al was reached.


RESULTS
The MGV of the Cu stepwedges fabricated by formularization were different than those of Al (p=0.001). Iteration method led to MGV similar to those of the Al stepwedge (p=0.207).


CONCLUSIONS
Construction of a Cu stepwedge according to the basic rules of radiophysic failed to result in a stepwedge with similar radiodensity values to those of Al stepwedge. Further studies may use the formularization method only for prototype Cu wedge production, but consecutive iterations shall be compassed to obtain the best approximation to Al MGV.
Dündar
Nesrin
N
Faculty of Dentistry, Department of Oral Diagnosis and Oral Radiology, Ege University, Bornova, Izmir, Turkey. nesrinergul@yahoo.com
Güneri
Pelin
P
Onem
Erinç
E
Boyacioğlu
Hayal
H
D015502:Absorptiometry, Photon / Q000295:instrumentation*; D000465:Algorithms; D000535:Aluminum / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D055620:Optical Phenomena; D011829:Radiation Dosage; D011862:Radiography, Panoramic / Q000295:instrumentation* / Q000592:standards; D012015:Reference Standards; D013054:Spectrophotometry, Atomic; D013499:Surface Properties; D014962:X-Ray Film / Q000592:standards
D003300:Copper; D000535:Aluminum