Multislice CT of the pelvis: dose reduction with regard to image quality using 16-row CT

Area of Science:

• Radiology
• Medical Imaging
• Radiation Dose Optimization

Background:

• Multi-detector CT (MDCT) protocols require optimization for radiation dose reduction while maintaining diagnostic image quality.
• Pelvic examinations are crucial for diagnosing various pathologies, necessitating clear visualization of bony structures and joints.

Purpose of the Study:

• To determine optimal examination parameters for 16-row MDCT of the pelvis to reduce radiation dose without compromising image quality.
• To evaluate the impact of stepwise tube current reduction on the visualization of pelvic anatomy, including the acetabulum and iliosacral joints.

Main Methods:

• 16-row MDCT scans of 12 cadaver pelvis specimens were performed with tube current reduced stepwise from 160 mA to 20 mA at 120 kV.
• Axial and coronal reconstructions were assessed by three radiologists using a 5-point Likert scale for image quality, noise, and detail of cortex, trabeculae, acetabulum, and iliosacral joints.
• Observer agreement was quantified using the kappa coefficient.

Main Results:

• Image quality significantly deteriorated between 80 mA and 28 mA.
• Adequate image quality for detailed acetabulum and iliosacral joint assessment was achieved at 40 mA (effective dose: 2.2 mSv).
• Acceptable image quality for remaining criteria was obtained at 80 mA (effective dose: 4.4 mSv), representing a 33% dose reduction compared to previous standards.

Conclusions:

• Pelvic MDCT imaging using a 16-row system provides acceptable image quality at 80 mA and 120 kV.
• The study identified specific tube current settings (40 mA and 80 mA) that balance diagnostic image quality with significant radiation dose reduction for pelvic examinations.
• These findings support the implementation of optimized, lower-dose protocols for routine pelvic MDCT scans.