Minimum Clinically Achievable Dose for Detecting Liver Lesions Using Deep Learning Image Reconstruction: A Phantom
Zhijie Pan1, Min Xu1, Tingting Qu1
1Radiology Department, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China (Z.P., M.X., T.Q, Y.Z., L.Z., Q.L., X.X).
Academic Radiology
|March 4, 2026
Summary
Deep learning image reconstruction (DLIR) at ultra-low doses significantly improves focal liver lesion (FLL) detection compared to standard dose methods. This advanced CT imaging technique offers a safer and more accurate approach for FLL screening and follow-up.
Area of Science:
- Radiology and Medical Imaging
- Artificial Intelligence in Healthcare
- Oncology Imaging
Background:
- Focal liver lesions (FLLs) require accurate detection for timely diagnosis and treatment.
- Standard CT protocols for FLL detection involve significant radiation exposure.
- Deep learning image reconstruction (DLIR) offers potential for dose reduction while maintaining image quality.
Purpose of the Study:
- To evaluate the performance of DLIR at ultra-low dose (4.5 mGy) for FLL detection.
- To compare DLIR performance against adaptive statistical iterative reconstruction-V (ASIR-V) at standard doses (10-15 mGy).
- To assess image quality, FLL detection rates, sensitivity, and specificity in both phantom and patient studies.
Main Methods:
- Phantom studies utilized a Gammex CT phantom with simulated FLLs to assess quantitative metrics.
- Prospective single-center study included 84 participants undergoing triple-phase upper-abdominal CT at a target dose of 4.5 mGy/phase.
- Images were reconstructed using DLIR and ASIR-V, followed by blinded radiologist evaluation of image quality and FLL detectability.
Main Results:
- DLIR at 4.5 mGy demonstrated superior quantitative metrics compared to ASIR-V at 10 mGy and 15 mGy in phantom studies.
- In patient studies, DLIR achieved significantly higher qualitative image quality (3.9 vs. 2.2) and FLL detection rates (93.0% vs. 77.5%) compared to ASIR-V.
- DLIR exhibited higher sensitivity (90.1%) and specificity (75.0%) for FLL detection than ASIR-V.
Conclusions:
- DLIR at 4.5 mGy provides substantial radiation dose reduction for FLL detection.
- DLIR outperforms ASIR-V at standard doses, offering superior image quality and detection performance.
- This ultra-low-dose DLIR protocol is a safe and accurate option for FLL screening and follow-up.
