Comprehensive integrated analysis of MR and DCE-MR radiomics models for prognostic prediction in nasopharyngeal carcinoma

Although prognostic prediction of nasopharyngeal carcinoma (NPC) remains a pivotal research area, the role of dynamic contrast-enhanced magnetic resonance (DCE-MR) has been less explored. This study aimed to investigate the role of DCR-MR in predicting progression-free survival (PFS) in patients with NPC using magnetic resonance (MR)- and DCE-MR-based radiomic models. A total of 434 patients with two MR scanning sequences were included. The MR- and DCE-MR-based radiomics models were developed based on 289 patients with only MR scanning sequences and 145 patients with four additional pharmacokinetic parameters (volume fraction of extravascular extracellular space (ve), volume fraction of plasma space (vp), volume transfer constant (Ktrans), and reverse reflux rate constant (kep) of DCE-MR. A combined model integrating MR and DCE-MR was constructed. Utilizing methods such as correlation analysis, least absolute shrinkage and selection operator regression, and multivariate Cox proportional hazards regression, we built the radiomics models. Finally, we calculated the net reclassification index and C-index to evaluate and compare the prognostic performance of the radiomics models. Kaplan-Meier survival curve analysis was performed to investigate the model’s ability to stratify risk in patients with NPC. The integration of MR and DCE-MR radiomic features significantly enhanced prognostic prediction performance compared to MR- and DCE-MR-based models, evidenced by a test set C-index of 0.808 vs 0.729 and 0.731, respectively. The combined radiomics model improved net reclassification by 22.9%-52.6% and could significantly stratify the risk levels of patients with NPC (p = 0.036). Furthermore, the MR-based radiomic feature maps achieved similar results to the DCE-MR pharmacokinetic parameters in terms of reflecting the underlying angiogenesis information in NPC. Compared to conventional MR-based radiomics models, the combined radiomics model integrating MR and DCE-MR showed promising results in delivering more accurate prognostic predictions and provided more clinical benefits in quantifying and monitoring phenotypic changes associated with NPC prognosis.

MR-DWI在腰椎間盤變性診斷中的價值

目的結合常規MR成像,對腰椎問盤變性的MR彌散加權成像(diffusion weighted imaging,DWI)進行分析,探討MR-DWI在腰椎間盤變性診斷中的價値。方法前瞻性對40例腰椎間盤檢查者,共200個腰椎間盤進行分析研究;其中正常腰椎間盤73個,變性椎間盤127個。所有病例均行常規MR檢查,包括失狀位T2WI,同時均行不同b値的MR弼散加權成像,b値分別選擇3OOs/mm^(2)、500 s/mm^(2)、1000 s/mm^(2);彌散加權成像採用失狀位掃描,利用工作站的Functool 2後處理軟體獲得每個椎間盤的表觀彌散係數(apparent diffusion coefficient,ADC)值,採用SPSS10.0軟體進行統計學分析,P<0.05爲顯著意義。結果1.73個正常椎間盤和127個變性椎間盤在b値爲3OOs/mm^(2)時,ADC値分別爲1.93×10^(-3)mm^(2)/s和1.49×10^(-3)mm^(2)/s,P<0.05;在b値爲500 s/mm^(2)時,ADC値分別爲1.88×10^(-3)mm^(2)/s和1.27×10^(-3)mm^(2)/s,P<0.05;在b値爲1000 s/mm^(2)時,ADC値分別爲1.48×10^(-3)mm^(2)/s和0.84×10^(-3)mm^(2)/s,P<0.05。2.200個椎間盤在不同b値彩色ADC圖中髓核顯示結果分析表明,當b値爲1000 s/mm^(2)時,髓核顯示最清楚,且與纖維環易分辨;當b値爲500 s/mm^(2)時,髓核顯示較模糊,與纖維環部份相融合,不易反映髓核的真實變化;當b値爲300 s/mm^(2)時,髓核顯示不清楚,髓核與纖維環之間不易分辨,與小b値受灌注影響大,不能有效反應水分子的彌散運動有關。3.在127個變性椎間盤中,表現爲T2WI信號正常,但DWI的ADC値下降,且髓核量減少者爲27個,佔21%,P<0.05>表明MR-DWI的敏感性較常規T2WI高。結論在腰椎間盤檢查時,應將MR-DWI掃描與常規MR檢查緊密結合,對提高腰椎間盤變性的診斷具有一定的價値;並以b値爲1000 s/mm^(2)時行DWI檢查首選,既可瞭解ADC値的變化,又可較直觀地在其彩色ADC圖中顯示側核和纖維環的變化。