Objectives Although magnetic resonance imaging (MRI) is widely used to evaluate extracranial vascular anomalies (VAs), its diagnostic accuracy remains uncertain. Methods We retrospectively assessed MRI accuracy for VAs and identified nonvascular lesions mimicking them. Patients who underwent surgical resection for suspected VAs at a tertiary referral center in Japan between April 2019 and June 2025 were analyzed. Results A total of 172 patients met the inclusion criteria (mean age 34.9 ± 18.8 years; 62.8% female). Lesions were most commonly located in the extremities (54.1%), followed by the head and neck (32.6%) and the trunk (13.4%). Histopathology identified venous malformations (VMs) as the most frequent subtype (73.8%), followed by arteriovenous malformations (AVMs; 11.0%) and lymphatic malformations (LMs; 6.4%). MRI showed moderate sensitivity and high specificity: AVM sensitivity 0.68 and specificity 0.99; VM sensitivity 0.70 and specificity 0.98; LM sensitivity 0.80 and specificity 0.98. Seven cases (4.1%) were ultimately diagnosed as non-VA lesions despite MRI findings suggestive of VAs. Common mimickers included angioleiomyoma and myopericytoma. Conclusions MRI demonstrates moderate sensitivity and strong specificity for VAs, although false-positive interpretations remain an important consideration.
M. Shiraishi, Kou Fujisawa, Yoichi Yasunaga et al.· Annals of Vascular Diseases· 0 citations
PURPOSE
To develop and externally validate a non-invasive framework for quantifying brain amyloid-β (Aβ) deposition using magnetic resonance fingerprinting (MRF) and neural network-based decoding, with positron emission tomography (PET) as the reference standard.
METHODS
This prospective multi-site study included 44 participants from 2 sites who had undergone, or were scheduled to undergo, Aβ PET within 1 year. MRF was performed on a 3T MR system using a 2D fast imaging with steady-state precession sequence with B1 correction, covering the whole brain in 9.5 min. PET images were co-registered to the MRF space, and regional amyloid load was calculated using an automated template-based pipeline. An inverse mapping function was implemented to convert MRF signals into amyloid burden maps. Repeatability, agreement with PET-based centiloid values, and associations with cognitive scores were evaluated.
RESULTS
The generated amyloid maps were visually similar to PET images. Test-retest analysis showed high repeatability, with a coefficient of variation of 1.8 ± 1.3% and an intraclass correlation coefficient of 0.84. In the external test set, MRF-based measurements correlated significantly with PET centiloid scores (Spearman's ρ = 0.589, P = 0.015) and Montreal Cognitive Assessment scores (ρ = -0.543, P = 0.020).
CONCLUSION
The proposed framework enables non-invasive Aβ mapping using a clinically feasible MRI protocol and may support repeated assessment for monitoring during anti-amyloid treatment.
Shohei Fujita, Yasutaka Fushimi, Y. Otsuka et al.· Magnetic Resonance in Medica...· 0 citations
