Meralgia paresthetica: from qualitative ultrasound assessment to quantitative multimodality imaging.

Meralgia paresthetica is a sensory mononeuropathy of the lateral femoral cutaneous nerve that remains frequently underdiagnosed despite its characteristic clinical presentation. Burning pain, paresthesia, and numbness over the anterolateral thigh may mimic hip, lumbar, or pelvic disorders, contributing to diagnostic delay. Imaging has gained increasing relevance in the evaluation of meralgia paresthetica, both for confirming neuropathy and for identifying contributory anatomical factors. High-resolution ultrasound enables direct visualization of the lateral femoral cutaneous nerve, characterization of its anatomical variants, and detection of focal changes at typical entrapment sites. Quantitative ultrasound parameters, particularly cross-sectional area, provide additional objective information and may help distinguish symptomatic nerves from normal variants, while elastography offers preliminary insight into chronic stiffness alterations. Magnetic resonance imaging complements ultrasound by allowing assessment of deeper nerve segments and by differentiating intrinsic signal abnormalities from extrinsic compression. Advanced techniques such as diffusion tensor imaging, although still investigational for this small sensory nerve, may eventually provide microstructural information beyond the capabilities of conventional sequences. This review summarizes current knowledge on the anatomy of the lateral femoral cutaneous nerve, outlines qualitative and quantitative ultrasound approaches, and discusses how multimodal imaging can support a more comprehensive and confident evaluation of patients with meralgia paresthetica.