A Practical Approach to Diagnosis of Spinal Dysraphism.

Spinal dysraphisms (SDs) are congenital malformations of the spinal cord, determined by derangement in the complex cascade of embryologic events involved in spinal development. They represent a heterogeneous group ranging from mild clinical manifestations-going unnoticed or being discovered at clinical examination-to a causal factor of life quality impairment, especially when associated with musculoskeletal, gastrointestinal, genitourinary, or respiratory system malformations. Knowledge of the normal embryologic development of the spinal cord-which encompasses three main steps (gastrulation, primary neurulation, and secondary neurulation)-is crucial for understanding the pathogenesis, neuroradiologic scenarios, and clinical-radiologic classification of congenital malformations of the spinal cord. SDs can be divided with clinical examination or neuroradiologic study into two major groups: open SDs and closed SDs. Congenital malformations of the spinal cord include a wide range of abnormalities that vary considerably in imaging and clinical characteristics and complexity and therefore may represent a diagnostic challenge, even for the experienced radiologist. Online supplemental material is available for this article. ©RSNA, 2021.

Magnetic resonance imaging evaluation of nigrosome 1 and neuromelanin can assist Parkinson's disease diagnosis, but requires an expert neuroradiologist.

INTRODUCTION: Parkinson's disease (PD) is the second most common neurodegenerative disease. However, the rate of misdiagnosis remains high, even at specialized movement disorder centers. PURPOSE: To assess the accuracy of nigrosome 1 and midbrain neuromelanin evaluation in the diagnosis of PD, and to identify possible differences in diagnostic accuracy between neuroradiologists of different experience levels in analyzing these structures. METHODS: A case-control study was conducted between April 2017 and January 2019. We prospectively evaluated 41 PD patients and 21 control individuals. Participants underwent axial, T2*-weighted, multi-echo gradient echo (GRE), and susceptibility-weighted imaging phase (SWIp) magnetic resonance imaging (MRI) sequences to evaluate nigrosome 1 and axial, T1-weighted, turbo spin-echo magnetization transfer contrast (MTC) MRI sequences to evaluate midbrain neuromelanin. All MRI sequences were acquired at 3.0 T. The images were analyzed by two experienced neuroradiologists, one with and one without expertise in nigrosome 1 and neuromelanin imaging. The sensitivity, specificity, and accuracy of the diagnoses were calculated between PD patients vs. healthy participants and between the two neuroradiologists. RESULTS: The sensitivity and specificity of each imaging sequence for PD diagnosis were as follows: multi-echo, 100% and 86%; SWIp, 91% and 88%; and T1 MTC, 90% and 93%, respectively. The accuracy of clinical PD diagnosis was higher for the expert neuroradiologist compared to the neuroradiologist lacking expertise. CONCLUSION: Nigrosome 1 and midbrain neuromelanin represent useful tools for PD diagnosis. However, these structures should be evaluated by experienced neuroradiologists in order to ensure high accuracy and reproducibility.