Jianxing Qiu

Renal interstitial fibrosis (RIF) is currently assessed by invasive biopsy. This prospective study developed and validated a noninvasive random forest model combining multiparametric MRI and clinical biomarkers for identifying severe RIF in 116 patients with biopsy-confirmed renal disease. Quantitative parameters were extracted from IVIM, ASL, phase-contrast MRI, T1 mapping, and BOLD sequences. Fibrosis was classified as mild (<25%) or severe (≥25%). In the held-out test set, the random forest model achieved an AUC of 0.89 (95% CI 0.82–0.96), sensitivity of 0.91, and specificity of 0.73, significantly outperforming clinical-only (AUC 0.63), MRI-only (AUC 0.63), and combined LASSO logistic regression (AUC 0.73) benchmarks. The model also demonstrated superior calibration (Brier score 0.154) and net clinical benefit on decision curve analysis. This integrated MRI–clinical model shows promise for noninvasive identification of severe RIF and warrants external prospective validation.

Background: Traditional methods for evaluating split renal function, including contrast‐enhanced CT and radionuclide imaging, have limitations related to ionizing radiation or potentially nephrotoxic contrast agents. Purpose: To investigate the value of renal blood flow (RBF)‐weighted estimated glomerular filtration rate (eGFR) derived from arterial spin labeling (ASL)‐MRI in predicting split renal function in patients with suspected renal artery stenosis (RAS). Study Type: Retrospective. Population: Fifty‐three consecutive patients (21 females; mean age, 61.28 ± 13.50 years) with suspected RAS and renal insufficiency underwent renal ASL‐MRI. Field Strength/Sequence: 1. 5T ; 3D pseudo‐continuous ASL technique. Assessment: RBF and regions of interest (ROI) areas of the renal cortex and entire kidney were measured on oblique coronal ASL‐MRI perfusion maps. The RBF‐weighted eGFR (RBFw eGFR) for each kidney was derived by normalizing the RBF‐area product to the bilateral total eGFR. The radionuclide GFR (rGFR) obtained from renal dynamic radionuclide imaging was used as the reference standard. Statistical Test: Paired t ‐tests, one‐way repeated‐measures ANOVA, Bonferroni test, Pearson's correlation analysis, and receiver operating characteristic (ROC) curves were used. Statistical significance was set at p = 0.05. Results: The cortical and entire RBFw eGFR showed strong significant correlations with rGFR (r: 0.799 vs. 0.800). The cortical and entire RBFw eGFR had high diagnostic efficiency for differentiating severe, moderate, and mild renal insufficiency (AUC: 0.934 vs. 0.936, 0.927 vs. 0.928, and 0.873 vs. 0.865). Data Conclusions: The RBFw eGFR derived from ASL‐MRI demonstrated a significant correlation with rGFR and high diagnostic performance for differentiating split renal dysfunction grades, suggesting potential for split renal function assessment in patients with RAS. Evidence Level: 3 (Nonconsecutive cohort studies, usually retrospective with an imperfectly applied reference standard). Technical Efficacy: 2 (diagnostic accuracy/clinical efficacy).

To evaluate whether coronal reduced field-of-view (r-FOV) diffusion-weighted imaging (DWI) improves image quality and local T staging of upper tract urothelial carcinoma (UTUC) compared with conventional axial full field-of-view (f-FOV) DWI. In this retrospective single-center study, 60 patients with pathologically confirmed UTUC who underwent preoperative magnetic resonance urography (MRU) were included. The imaging protocol comprised both axial f-FOV DWI and coronal r-FOV DWI acquired on a 3.0-T scanner. Two radiologists independently assessed subjective image quality (sharpness, distortion, artifacts, and lesion conspicuity). Tumor contrast and apparent diffusion coefficient (ADC) values were measured. Local T staging was performed using each DWI sequence, with particular focus on identifying locally advanced disease (≥ T3). Histopathology from radical nephroureterectomy served as the reference standard. Coronal r-FOV DWI demonstrated significantly higher image quality scores across all subjective parameters than axial f-FOV DWI (all p ≤ 0.003). Tumor contrast was higher on r-FOV DWI (p < 0.001), and ADC values measured on r-FOV DWI were significantly lower than those on f-FOV DWI (p < 0.001), with a strong correlation between the two techniques (r = 0.765). High-grade UTUC showed significantly lower ADC values than low-grade tumors on both sequences (p < 0.05). For detecting locally advanced disease (≥ T3), coronal r-FOV DWI achieved higher sensitivity (91.7% vs. 75.0%), specificity (80.6% vs. 75.0%), and overall accuracy (85.0% vs. 75.0%) compared with axial f-FOV DWI. The addition of coronal r-FOV DWI was subjectively considered diagnostically useful in 91.7% of cases. Coronal r-FOV DWI significantly improves image quality, tumor conspicuity, and local T staging performance in UTUC compared with conventional axial f-FOV DWI. When incorporated as a complementary sequence in MRU, coronal r-FOV DWI provides added diagnostic value, particularly for identifying locally advanced disease.

Background: Previous research on the prognostic implications of left ventricular myocardial strain using cardiac magnetic resonance feature tracking (CMR-FT) in light-chain cardiac amyloidosis (AL-CA) has shown promising potential. This study aimed to evaluate the prognostic significance of global and segmental left ventricular myocardial strain in AL-CA patients, specifically analyzing the American Heart Association's 16 segments. Methods: A total of 75 consecutive patients (50 men, mean age: 55.6 ± 10.0 years) who underwent CMR examination with histologically confirmed systemic AL-CA were retrospectively enrolled between January 2014 and November 2022. Both global and segmental myocardial strain and the American Heart Association’s 16 segments were quantified using CMR-FT on the steady-state free precession (SSFP) cine sequence. A comparative analysis was conducted between survivors and non-survivors based on the defined endpoint. Student t-test or Mann–Whitney U, receiver operating characteristic curve, Kaplan–Meier event-free survival curve, and Cox proportional hazards regression were used. Significance was set at p < 0.05. Results: Following a median follow-up of 34 months, 16 out of 75 patients experienced mortality events. B-type natriuretic peptides (BNP) (p < 0.001), global radial strain (RSglobal) (p = 0.033), and RS in the basal inferior segment (RSbas-inferior) (p = 0.025) remained significant as independent predictors of all-cause mortality. The cut-off values were identified as 24.97% for RSglobal, and 20.97% for RSbas-inferior. Kaplan–Meier survival curves revealed significantly reduced event-free survival for individuals in the lower cut-off groups for RSglobal and RSbas-inferior (p = 0.013, p < 0.001, respectively). Conclusions: Radial strain for the global and the basal inferior segment may prove valuable for risk stratification in patients with AL-CA.

Purpose: To evaluate the efficacy of high b-value diffusion-weighted imaging (DWI) with a continuous-time random-walk (CTRW) diffusion model in determining the pathological grade and variant histology (VH) of bladder cancer (BCa).Methods: A total of 81 patients (median age, 70 years; range, 35-92 years; 18 females; 66 high grades; 30 with VH) with pathologically confirmed bladder urothelial carcinoma were retrospectively enrolled and underwent bladder MRI on a 3.0T MRI scanner. Multi-b-value DWI was performed using 11 b-values. Three CTRW model parameters were obtained: an anomalous diffusion coefficient (D) and two parameters reflecting temporal (α) and spatial (β) diffusion heterogeneity. The apparent diffusion coefficient (ADC) was calculated using b0 and b800. D, α, β, and ADC were statistically compared between high- and low-grade BCa, and between pure urothelial cancer (pUC) and VH. Comparisons were made using the Mann–Whitney U test between different pathological states. Receiver operating characteristic curve analysis was used to assess performance in differentiating the pathological states of BCa.Results: ADC, D, and α were significantly lower in high-grade BCa compared to low-grade, and in VH compared to pUC (p < 0.001), while β showed no significant differences (p > 0.05). The combination of D and α yielded the best performance for determining BCa grade and VH (area under the curves = 0.913, 0.811), significantly outperforming ADC (area under the curves = 0.823, 0.761).Conclusion: The CTRW model effectively discriminated pathological grades and variants in BCa, highlighting its potential as a noninvasive diagnostic tool.

Objective To investigate the feasibility of deep learning–based MRI (DL-MRI) in its application in shoulder imaging and compare its performance with conventional MR imaging (non-DL-MRI). Methods This retrospective study was approved by the local ethics committee. Seventy consecutive patients who had been examined with both DL-MRI and non-DL-MRI were enrolled for the image quality and lesion diagnosis comparison. Another 400 patients had been examined only with DL-MRI. Their images’ quality was assessed by 20 radiologists using a satisfaction survey. The Kendall W test was performed to assess interobserver agreement. The Wilcoxon test was performed to compare the image quality. For lesion diagnosis, the interobserver and interstudy agreement were evaluated by kappa analysis. Results The scan time of DL-MRI (6 min 1 s) was nearly 50% decreased compared with that of non-DL-MRI (11 min 25 s). The image quality was higher in both PDWI (4.85 ± 0.31 for DL, and 4.73 ± 0.29 for non-DL) and T2WI (4.95 ± 0.2 for DL, and 4.74 ± 0.41 for non-DL) of DL-MRI. Good interobserver agreement was found for the image quality of all the MR sequences on both DL-MRI (Kendall W: 0.588~0.902) and non-DL-MRI (Kendall W: 0751~0.865). Both the SNRs and |CNR| were significantly higher in PDWI and T2WI of DL-MRI. High interobserver and interstudy agreements for the lesions in non-DL-MRI and DL-MRI (kappa value = 0.913 to 1.000) were observed. The results of the image quality satisfaction survey in 400 patients receiving DL-MRI in the shoulder obtained 5 scores among all the radiologists. Conclusion Shoulder DL-MRI can greatly reduce the scan time, while improve imaging quality of PDWI and T2WI compared to non-DL-MRI. Key Points • Shoulder 2D DL-MRI can greatly reduce the whole scan time and improve imaging quality of both PDWI and T2WI compared to conventional parallel MRI. • Shoulder 2D DL-MRI could be a clinical routine with greatly improved work efficiency in the future.

Objectives To compare the image quality of breath-hold magnetic resonance cholangiopancreatography (BH-MRCP) and respiratory-gating MRCP (RG-MRCP), and to explore breathing curve–based factors and patient-related data affecting image quality. Methods A total of 126 participants who underwent RG-MRCP and BH-MRCP on a 3-T magnetic resonance (MR) scanner were enrolled from May to December 2021. The images were evaluated by three radiologists on a 5-point scale. Respiratory parameters were extracted from the breathing curves. The Wilcoxon test was used to compare the image quality between the two MRCPs. Logistic regression analyzes were performed to identify age, sex, abdominal pain, and breathing predictor variables of better image quality. Results BH-MRCP performed better in visualizing intrahepatic bile ducts and overall image quality than RG-MRCP (p < 0.01). Factors predicting relatively good image quality included lower standard deviation of the respiratory amplitude (SD_amp)-minimum-peak (odds ratio = 0.16, p < 0.01) for RG-MRCP and lower SD_amp (OR = 0.69, p < 0.01) for BH-MRCP. Conclusions BH-MRCP had significantly better overall image quality than RG-MRCP. Respiratory conditions exerted a significant impact on MRCP image quality, and parameters derived from the breathing curve could help predict the image quality of both sequences. Key Points • Both breath-hold (BH) and respiratory-gating (RG) MRCP demonstrate satisfying image quality. • BH-GRASE-MRCP is significantly better than RG-MRCP at the group level, but not for every individual. • Respiratory conditions exert a significant impact on the image quality, and the breathing curve can help predict the image quality.

Purpose: To compare the performance of 3D MRU based on a breath-hold gradient- and spin-echo (BH-GRASE) technique with conventional 3D respiratory-triggered FSE (RT-FSE) sequence in patients with urinary tract dilation. Methods: We prospectively included 90 patients with urinary tract dilation who underwent both 3D BH-GRASE and RT-FSE MRU at 3T. The acquisition time of two MRU sequences was recorded. Three readers blinded to the protocols reviewed the image quality using a five-point scale and assessed the diagnostic performance related to urinary tract dilation. The relative contrast ratio (CR) between the urinary tract and adjacent area was measured quantitatively. Results: Acquisition time was 14.8 s for BH-GRASE MRU and 213.6 ± 52.2 s for RT-FSE MRU. The qualitative image analysis demonstrated significant equivalence between the two MRU protocols. 3D BH-GRASE MRU better depicted bilateral renal calyces than RT-FSE MRU (p < 0.05). The CR values of the urinary tract were lower on BH-GRASE MRU compared with RT-FSE MRU (p < 0.05). There were excellent agreements in the assessment of urinary tract dilation between BH-GRASE and RT-FSE MRU, including the dilated degree, obstructive level, and obstructive imaging features (inter-sequence κ = 0.924–1). Conclusion: 3D BH-GRASE MRU significantly decreased the acquisition time and achieved comparable image quality, urinary tract visualization, and diagnostic performance with conventional 3D RT-FSE MRU. Breath-hold 3D MRU with GRASE may provide a feasible evaluation of urinary tract dilation. Graphical