Intravoxel incoherent motion combined with conventional MRI for the differentiation of benign, intermediate, and malignant fibrous soft-tissue tumors

Front Oncol. 2026 Jun 26;16:1863609. doi: 10.3389/fonc.2026.1863609. eCollection 2026.

ABSTRACT

BACKGROUND: Fibroblastic/myofibroblastic tumors are among the most common soft-tissue tumors (STTs) encountered clinically. Several magnetic resonance imaging (MRI) features associated with malignant tumors overlap with benign tumors, making differential diagnosis challenging. Intravoxel incoherent motion (IVIM) is a valuable MRI technique for differentiating various tumors. This study aims to evaluate the abilities of conventional MRI and IVIM in differentiating benign, intermediate, and malignant fibrous STTs.

METHODS: Fifty-five patients with fibrous STTs were prospectively enrolled, comprising 18 benign, 18 intermediate, and 19 malignant cases. All the patients underwent MRI examinations including IVIM. Conventional MRI signs and standard-apparent diffusion coefficient (ADC), true diffusion coefficient (D), pseudo-diffusion coefficient (D^*), and perfusion fraction (f) were recorded. Statistical analyses were performed using Kruskal-Wallis H test, Chi-square test,post hoc test with Bonferroni correction, receiver operating characteristic (ROC) curves, and DeLong test. p < 0.05 indicated statistical significance.

RESULTS: Malignant tumors had higher heterogeneity on T2WI (p = 0.020 and 0.009) and contrast enhancement T1WI (p = 0.013 and 0.029), and were more prone to necrosis (p < 0.001 andp = 0.001) compared with benign and intermediate tumors, respectively. Tail-like pattern (p = 0.034 and 0.009) and invasiveness (p = 0.018 and 0.033) were more frequently observed in intermediate and malignant tumors than in benign tumors, respectively. Standard-ADC_mean, standard-ADC_min, D_mean, and D_min values decreased from benign to intermediate and malignant fibrous STTs. Malignant STTs displayed higher f_mean and f_min values than benign tumors (p = 0.002 and 0.013, respectively). Standard-ADC_mean showed the highest AUC (0.894) in differentiating intermediate from benign STTs. D_mean showed the highest AUC (0.961 and 0.905) in differentiating malignancies from benign and intermediate STTs, respectively. For discriminating between benign and non-benign fibrous STTs, the combination of conventional MRI signs and IVIM parameters yielded the highest AUC of 0.971.

CONCLUSION: IVIM diffusion parameters differentiated benign, intermediate, and malignant fibrous STTs and can complement conventional MRI signs.

PMID:42434743 | PMC:PMC13349916 | DOI:10.3389/fonc.2026.1863609