Optimizing effective dose and image quality in cone beam CT sialography

Area of Science:

• Radiology
• Medical Imaging
• Radiation Dosimetry

Background:

• Cone beam computed tomography (CBCT) sialography is a valuable tool for visualizing salivary gland anatomy and pathology.
• Optimizing radiation dose and image quality is crucial for patient safety and diagnostic accuracy in CBCT procedures.

Purpose of the Study:

• To develop and validate protocols for CBCT sialography that minimize patient radiation dose while maintaining diagnostic image quality for the major salivary glands.

Main Methods:

• Radiation absorbed dose measurements were performed using a RANDO phantom at various peak kilovoltage (kVp) and milliamperage (mA) settings.
• Effective doses were calculated for submandibular and parotid gland imaging using specific field of view (FOV) dimensions.
• Image quality was assessed using signal difference-to-noise ratio (SDNR) and figure-of-merit (FOM).

Main Results:

• Optimal parameters for submandibular CBCT sialography were identified as 85 kVp and 6 mA, yielding a mean effective dose of 82.47 µSv and a mean FOM of 2.33 µSv⁻¹.
• For parotid CBCT sialography, optimal settings were 70 kVp and 6 mA, resulting in a mean effective dose of 39.99 µSv and a mean FOM of 7.60 µSv⁻¹.
• The chosen parameters achieved a balance between reduced radiation exposure and acceptable image quality metrics.

Conclusions:

• Low-dose, 3-dimensional CBCT sialography protocols can be effectively implemented for major salivary gland imaging.
• Utilizing localized, small fields of view (FOVs) is key to achieving high image quality with minimal effective radiation dose.
• These optimized protocols enhance patient safety without compromising the diagnostic utility of CBCT sialography.