Optimisation of tube voltage for conventional urography using a Gd2O2S:Tb flat panel detector

Area of Science:

• Medical Imaging
• Radiological Physics

Background:

• Computed tomography (CT) has shifted urography indications towards high-contrast details.
• Conventional projection urography requires optimized beam quality for modern detectors.

Purpose of the Study:

• To optimize X-ray beam quality for urography with a Gadolinium Oxysulfide:Terbium (Gd(2)O(2)S:Tb) flat-panel detector.
• To evaluate image quality and effective dose at different tube voltages.

Main Methods:

• Utilized an anthropomorphic phantom and a CXDI-40G detector for image acquisition at varying tube voltages.
• Conducted visual grading characteristics (VGCs) studies with radiologists and residents to assess image quality.
• Performed a clinical study with 62 patients comparing 55 kV and 73 kV, including simulated dose reductions.

Main Results:

• The optimal tube voltage for image quality was determined to be 55 kV.
• Images acquired at 55 kV with 85% of the original dose showed comparable quality to 73 kV images at 100% dose.
• Effective dose reduction of approximately 10-20% was achieved by using 55 kV instead of 73 kV.

Conclusions:

• A low tube voltage is recommended for conventional urography focusing on high-contrast details.
• Using 55 kV with a Gd(2)O(2)S:Tb flat-panel detector can reduce effective dose by 10-20% while maintaining image quality.
• This optimization enhances patient safety in urographic examinations.