Thin-slice T-weighted images and deep-learning-based super-resolution reconstruction: improved preoperative assessment of vascular invasion for pancreatic ductal adenocarcinoma.

Purpose: To evaluate the efficacy of thin-slice T-weighted imaging (TWI) and super-resolution reconstruction (SRR) for preoperative assessment of vascular invasion in pancreatic ductal adenocarcinoma (PDAC).

Methods: Ninety-five PDACs with preoperative MRI were retrospectively enrolled as a training set, with non-reconstructed TWI (NRT) in different slice thicknesses (NRT-3, 3 mm; NRT-5, ≥ 5 mm). A prospective test set was collected with NRT-5 (n = 125) only. A deep-learning network was employed to generate reconstructed super-resolution TWI (SRT) in different slice thicknesses (SRT-3, 3 mm; SRT-5, ≥ 5 mm). Image quality was assessed, including the signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and signal-intensity ratio (SIR, tumor/pancreas; SIR, tumor/background). Diagnostic efficacy for vascular invasion was evaluated using the area under the curve (AUC) and compared across different slice thicknesses before and after reconstruction.

Results: SRT-5 demonstrated higher SNR and SIR compared to NRT-5 (74.18 vs 72.46; 1.42 vs 1.30; p < 0.05). SRT-3 showed increased SIR and SIR over NRT-3 (1.35 vs 1.31; 2.73 vs 2.58; p < 0.05). SRT-5 showed higher CNR, SIR and SIR than NRT-3 (p < 0.05). NRT-3 outperformed NRT-5 in evaluating venous invasion (AUC: 0.732 vs 0.597, p = 0.021). SRR improved venous assessment (AUC: NRT-3, 0.927 vs 0.732; NRT-5, 0.823 vs 0.597; p < 0.05), and SRT-5 exhibits comparable efficacy to NRT-3 in venous assessment (AUC: 0.823 vs 0.732, p = 0.162).

Conclusion: Thin-slice TWI and SRR effectively improve the image quality and diagnostic efficacy for assessing venous invasion in PDAC. Thick-slice TWI with SRR is a potential alternative to thin-slice TWI.

Critical Relevance Statement: Both thin-slice T-WI and SRR effectively improve image quality and diagnostic performance, providing valuable options for optimizing preoperative vascular assessment in PDAC. Non-invasive and accurate assessment of vascular invasion supports treatment planning and avoids futile surgery.

Key Points: Vascular invasion evaluation is critical for the surgical eligibility of PDAC. SRR improved image quality and vascular assessment in TWI. Utilizing thin-slice TWI and SRR aids in clinical decision making for PDAC.