Diagnostic Value of Multi-Echo Quantitative Susceptibility Mapping for the Central Vein Sign in Brain Capillary Telangiectasia

Objective To explore the diagnostic value of high-resolution dual-echo quantitative susceptibility mapping (QSM) in demonstrating the characteristic central vein sign (CVS) of brain capillary telangiectasia (BCT). Methods This study prospectively analyzed 40 patients with BCT confirmed by multi-echo QSM examination. All patients were imaged using a 3.0T MR scanner, including conventional sequences and dual-parameter multi-echo QSM sequences (slice thicknesses of 0.8 mm and 0.4 mm). By analyzing QSM-reconstructed Magnitude-separate images, susceptibility-weighted imaging (SWI) images, and QSM maps, their ability to display the CVS in BCT was evaluated, using the "target sign" as the diagnostic standard. The detection rates of the CVS among different sequences and slice thicknesses were compared using the χ² test or Fisher's exact test, with P < 0.05 considered statistically significant. Results A total of 728 lesions were detected in the 40 BCT patients, with multiple lesions being predominant (39 cases), most commonly located in the brainstem, basal ganglia, and thalamus. Under the condition of TE=22.5 ms, the Magnitude-separate sequence showed the highest detection rate for the CVS (0.8 mm slice thickness: 68.8%; 0.4 mm slice thickness: 81.7%), significantly higher than SWI sequences (0.8 mm: 28.3%; 0.4 mm: 41.9%) and QSM maps (0.8 mm: 21.6%; 0.4 mm: 44.4%). Chi-square test analysis showed that the detection rate of the Magnitude-separate sequence was significantly higher than that of other sequences (P < 0.05). Reducing the slice thickness to 0.4 mm significantly improved the detection rate for all sequences, with the QSM map showing the most pronounced improvement (a 2.056-fold increase). The QSM map clearly displayed the central vein as high signal, forming a typical "double-ring target sign". Conclusion High-resolution multi-echo QSM is a highly sensitive imaging method for demonstrating the characteristic CVS in BCT. Among the sequences, the thin-slice (0.4 mm) Magnitude-separate sequence yielded the optimal detection rate. The QSM map can intuitively reflect the distribution of deoxyhemoglobin within the lesion, clearly presenting the CVS and the "target sign", which holds significant value for the accurate and differential diagnosis of BCT.