Low-dose corticomedullary phase CT urography with artificial intelligence iterative reconstruction for bladder cancer evaluation

Haifeng Liu; Xinrui Jiang; Tiantian Wang; Guozhi Zhang; Ming Zhao; Wei Xiang; Hongfen Peng

doi:10.1093/bjr/tqaf315

Low-dose corticomedullary phase CT urography with artificial intelligence iterative reconstruction for bladder cancer evaluation

Br J Radiol. 2025 Dec 24:tqaf315. doi: 10.1093/bjr/tqaf315. Online ahead of print.

Authors

Haifeng Liu¹, Xinrui Jiang², Tiantian Wang³, Guozhi Zhang³, Ming Zhao¹, Wei Xiang⁴, Hongfen Peng¹

Affiliations

¹ Department of Radiology, Wuhan No.1 Hospital, Wuhan, Hubei, 430022, China.
² Hubei University of Chinese Medicine, Wuhan, Hubei, 430065, China.
³ United Imaging Healthcare, Shanghai, 201800, China.
⁴ Department of Urology, Wuhan No.1 Hospital, Wuhan, Hubei, 430022, China.

PMID: 41442462
DOI: 10.1093/bjr/tqaf315

Abstract

Objectives: To test the feasibility and quantify the performance of low-dose CT urography (CTU) with artificial intelligence iterative reconstruction (AIIR) for bladder cancer (BC) evaluation.

Methods: A total of 122 patients undergoing CTU examination were prospectively enrolled, where the routine-dose scan (120 kVp, ref 100 mAs) at corticomedullary phase (CMP) was followed immediately by a low-dose scan (120 kVp, ref 20 mAs). Routine-dose images were reconstructed with hybrid iterative reconstruction (HIR, RD-HIR), while low-dose images were with AIIR (LD-AIIR) and HIR (LD-HIR). The image quality was first evaluated regarding streak artifacts around the bladder and then in contrast-to-noise ratio (CNR) for various manifestations of bladder wall. The diagnostic performance of BC was characterized using receiver operating characteristic (ROC) analysis, in respect to the clinical diagnostic report.

Results: The effective dose at low-dose CMP was 80.2% lower than routine-dose scan (7.6 ± 1.2 vs 1.5 ± 0.3 mSv). Nineteen cases in LD-HIR were deemed clinically unacceptable for presenting severe artifacts around the bladder, while found well above the basic requirement in LD-AIIR. The highest CNR was found in LD-AIIR in all scenarios (all p < 0.001). The area under ROC curve in LD-AIIR was comparable to RD-HIR (0.988 vs. 0.990, p = 0.172) and significantly higher than LD-HIR (0.988 vs. 0.831, p < 0.001).

Conclusions: The low-dose AIIR protocol allows for a profound dose reduction (80.2%) while maintaining reliable diagnosis of bladder cancer on corticomedullary phase CTU images.

Advances in knowledge: Corticomedullary phase CTU with AIIR permits 80.2% dose reduction while preserving reliable BC diagnosis.

Keywords: Artificial intelligence iterative reconstruction; Bladder cancer; Computed tomography urography; Radiation dosage.

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