Value of delayed post-contrast phase hyperintensity on gadobenate dimeglumine-enhanced MRI for differentiating...

Incidental splenic cystic lesions are commonly encountered on MRI. Atypical hemangiomas with absent enhancement on conventional MRI (cMRI) may be misdiagnosed as simple cysts, yet they carry a small risk of spontaneous rupture. Delayed post‑contrast phase imaging using gadobenate dimeglumine (Gd-BOPTA) may detect contrast retention in hemangiomas, offering a potential discriminator. This study provides an exploratory evaluation of whether delayed post-contrast hyperintensity can help differentiate atypical splenic hemangiomas from true cysts.

In this exploratory retrospective, single‑center study, we searched our PACS database for reports of splenic cysts or hemangiomas between June 2015 and June 2025. A consecutive series of 220 patients (162 lesions initially classified as cysts on cMRI, 58 as hemangiomas) was included. Two independent radiologists, blinded to clinical data and reference standard, assessed cMRI features and delayed post-contrast phase signal intensity. The index test was delayed post-contrast phase hyperintensity (yes/no). The reference standard was histopathology in an exploratory validation subset (n = 26); for the full cohort (n = 220), imaging findings were descriptively reported. Diagnostic accuracy metrics (sensitivity, specificity, positive predictive value [PPV], negative predictive value [NPV]) were explored in the pathologically confirmed subset with 95% confidence intervals using the Wilson score method.

Interobserver agreement was excellent for cMRI classification (κ = 0.86) and delayed post-contrast phase signal assessment (κ = 0.88). In the full cohort (n = 220), 82/162 (50.6%) of cMRI‑diagnosed cysts exhibited delayed post‑contrast hyperintensity, representing an imaging feature discordant with a simple cyst. Among the 26 pathologically confirmed lesions (validation subset), 18 were hemangiomas and 8 were cysts. Delayed post-contrast hyperintensity demonstrated, sensitivity 94.4% (95% CI: 72.7-99.9%), specificity 100% (95% CI: 67.6-100%), PPV 100% (95% CI: 81.6-100%), and NPV 88.9% (95% CI: 56.5-98.0%). The wide confidence intervals reflect the small sample size (n = 26) and inherent imprecision of these exploratory estimates.

Delayed post-contrast hyperintensity on Gd-BOPTA-enhanced MRI is a potential imaging sign for differentiating atypical splenic hemangiomas from true cysts. This exploratory observation warrants prospective validation before clinical adoption.