Observer performance for adaptive, image-based denoising and filtered back projection compared to scanner-based...

Area of Science:

• Radiology
• Medical Imaging
• Gastroenterology

Background:

• Low-dose CT enterography (LD-CTE) is crucial for diagnosing intestinal inflammation.
• Optimizing image reconstruction techniques is essential for accurate detection at reduced radiation doses.
• Scanner-based iterative reconstruction (IR) is a common method, but vendor-independent alternatives are being explored.

Purpose of the Study:

• To compare observer performance in detecting intestinal inflammation using LD-CTE.
• To evaluate scanner-based IR against vendor-independent adaptive noise reduction (ANLM) and filtered back projection (FBP).

Main Methods:

• Sixty-two LD-CTE exams were reconstructed using IR, ANLM, and FBP.
• Three blinded readers marked intestinal inflammation on images.
• A reference standard was established by expert review.
• Non-inferiority was assessed using Jackknife free-response ROC (JAFROC) figures of merit (FOM).

Main Results:

• ANLM and FBP demonstrated non-inferior observer performance compared to IR (JAFROC FOM 0.84 for all).
• Sensitivity and specificity confidence intervals widely overlapped across all reconstruction methods.
• Image quality was rated higher for IR and ANLM compared to FBP (p < 0.0001).

Conclusions:

• Vendor-independent ANLM and FBP offer observer performance comparable to scanner-based IR for LD-CTE.
• ANLM maintained or improved image quality ratings relative to FBP at low radiation doses.
• These findings support the use of alternative reconstruction methods for effective LD-CTE.