Application of adaptive non-linear 2D and 3D postprocessing filters for reduced dose abdominal CT

Area of Science:

• Medical Imaging
• Radiology
• Image Processing

Background:

• Abdominal computed tomography (CT) is a common procedure with significant radiation exposure.
• Postprocessing filters offer a potential method for dose reduction without compromising image quality.

Purpose of the Study:

• To evaluate and compare the effectiveness of 2D and 3D non-linear adaptive filters in improving reduced dose abdominal CT images.

Main Methods:

• Reduced dose abdominal CT images (12 mGy and 6 mGy CTDIvol) were postprocessed using 2D and 3D filters.
• Six radiologists conducted blinded, randomized side-by-side assessments of image quality.
• Objective noise levels were measured, and data analyzed using visual grading regression and mixed linear models.

Main Results:

• 3D filtered images demonstrated superior image quality across all criteria compared to reduced dose unfiltered and 2D filtered images (P < 0.01).
• While standard dose images were rated higher than 3D filtered images (P < 0.01), noise levels were similar.
• For patients with BMI < 30 kg/m², 3D filtered images were comparable to standard dose images for most criteria.

Conclusions:

• Three-dimensional (3D) filtered reduced dose abdominal CT images offer superior quality over unfiltered and 2D filtered images.
• 3D filtered images provide comparable quality to standard dose CT scans in patients with a BMI below 30 kg/m².