Combining T1rho and advanced diffusion MRI for noninvasively staging liver fibrosis: an experimental study in rats.

PURPOSE: To investigate the value of imaging parameters derived from T1 relaxation times in the rotating frame (T1ρ or T1rho), diffusion kurtosis imaging (DKI) and intravoxel incoherent motion (IVIM) in assessment of liver fibrosis in rats and propose an optimal diagnostic model based on multiparametric MRI. METHODS: Thirty rats were divided into one control group and four fibrosis experimental groups (n = 6 for each group). Liver fibrosis was induced by administering thioacetamide (TAA) for 2, 4, 6, and 8 weeks. T1ρ, mean kurtosis (MK), mean diffusivity (MD), perfusion fraction (f), true diffusion coefficient (D), and pseudo-diffusion coefficient (D*) were measured and compared among different fibrosis stages. An optimal diagnostic model was established and the diagnostic efficiency was evaluated by receiver operating characteristic (ROC) curve analysis. RESULTS: The mean AUC values, sensitivity, and specificity of T1ρ and MD derived from DKI across all liver fibrosis stages were comparable but much higher than those of other imaging parameters (0.954, 92.46, 91.85 for T1ρ; 0.949, 92.52, 91.24 for MD). The model combining T1ρ and MD exhibited better diagnostic performance with higher AUC values than any individual method for staging liver fibrosis (≥ F1: 1.000 (0.884-1.000); ≥ F2: 0.935 (0.782-0.992); ≥ F3: 0.982 (0.852-1.000); F4: 0.986 (0.859-1.000)). CONCLUSION: Among the evaluated imaging parameters, T1ρ and MD were superior for differentiating varying liver fibrosis stages. The model combining T1ρ and MD was promising to be a credible diagnostic biomarker to detect and accurately stage liver fibrosis.

Prognostic value of platelet-to-lymphocyte ratio in patients with unresectable hepatocellular carcinoma undergoing transarterial chemoembolization and tyrosine kinase inhibitors plus immune checkpoints inhibitors.

Purpose: To investigate the prognostic value of platelet-to-lymphocyte ratio (PLR) in patients with unresectable hepatocellular carcinoma (uHCC) treated with transarterial chemoembolization (TACE) and tailored tyrosine kinase inhibitors (TKIs) plus immune checkpoints inhibitors (ICIs). Materials and methods: Ninety-eight patients from May 2018 to January 2022 in our hospital were enrolled in this study. The receiver operating characteristic (ROC) curve analysis was performed and the corresponding Youden index was used to determine the optimal PLR cut-off. Overall survival (OS), progression-free survival (PFS), and adverse events (AEs) of patients were evaluated based on the PLR cut-off. The factors affecting survival were assessed using univariate and multivariate Cox proportional hazards regression analyses. Results: The PLR cut-off was 98.89. There were 49 patients in the low pretreatment PLR group (PLR ≤ 98.89) and 49 patients in the high PLR group (PLR > 98.89). Patients with low pretreatment PLR had significantly longer median OS (25.7 months vs 16.1 months; P < 0.001) and PFS (14.9 months vs 10.2 months; P < 0.001) than those with high pretreatment PLR. The multivariate analysis revealed that ALT, tumor size, and PLR are risk factors affecting OS. The three independent factors affecting PFS are tumor size, AFP, and PLR. The AEs were tolerable and manageable. Conclusion: The low pretreatment PLR (PLR ≤ 98.89) was an independent protective factor for the survival outcomes of patients in this study. PLR was helpful for clinicians to predict the prognosis and identify the patients with uHCC who were most likely to benefit from TACE + TKIs + ICIs.

Utility of Dark-Blood Dual-Energy CT Images for Predicting Vascular Involvement and R0 Resection in Patients With Pancreatic Cancer.

BACKGROUND. Current CT criteria for assessing vascular involvement by pancreatic ductal adenocarcinoma (PDAC) use circumferential contact as an indirect indicator. Dark-blood images derived from dual-energy CT (DECT) provide high lumen-to-wall contrast and may aid assessment. OBJECTIVE. The purpose of this study was to compare the diagnostic performance of 55-keV virtual monoenergetic images (VMIs) assessed using NCCN criteria with that of dark-blood images assessed using wall-based criteria for predicting vascular involvement and surgical resection that achieves microscopically negative margins (i.e., R0 resection) in patients with PDAC who undergo contrast-enhanced DECT. METHODS. This retrospective study included 109 patients (mean age, 62.6 ± 8.8 [SD] years; 66 men, 43 women) with histologically confirmed PDAC who underwent pancreatic parenchymal and portal venous phase DECT within 4 weeks before surgery (including PDAC resection in 73 patients) between July 2020 and June 2022. Dark-blood images were derived using a two-material decomposition algorithm. Two radiologists independently reviewed 55-keV VMIs and dark-blood images in separate sessions to evaluate celiac artery, common hepatic artery, superior mesenteric artery, portal vein, and superior mesenteric vein involvement; a third radiologist resolved discrepancies. On 55-keV VMIs, vessel relationships were classified as no contact, abutment (≤ 180° contact), or encasement (> 180° contact). On dark-blood images, vessel walls were categorized as intact circumferentially, irregular, or discontinuous. Tumor resectability status was classified on the basis of vessel relationships. Surgical observation served as the reference for vascular involvement. Margin status was determined for resected tumors. RESULTS. Across the five vessels, for predicting vascular involvement, abutment or encasement on 55-keV VMIs had sensitivity of 100.0% (all vessels) and specificity of 66.2-92.9%, and an irregular or discontinuous wall on dark-blood images had sensitivity of 80.0-100.0% and specificity of 88.2-98.0%. Specificity was higher for an irregular or discontinuous wall than for abutment or encasement for all vessels (all p < .05); sensitivity was not different for any vessel (all p > .05). Resectable disease classified by dark-blood images, compared with resectable disease classified by 55-keV VMIs, showed no difference in sensitivity (89.5% vs 78.9%, p = .33) but showed higher specificity (75.9% vs 59.3%, p = .01) for predicting R0 resection. CONCLUSION. Dark-blood images showed higher diagnostic performance than 55-keV VMIs for predicting vascular involvement and R0 resection in patients with PDAC. CLINICAL IMPACT. Dark-blood images may aid decisions regarding neoadjuvant therapy and surgical planning for PDAC.