Giulia Moltoni

Introduction: The corpus callosum (CC) is critical for inter-hemispheric integration, and its structural abnormalities have been implicated in the neurobiology of schizophrenia (SCZ). Approximately 20-35% of SCZ patients exhibit resistance to antipsychotics and are classified as treatment-resistant schizophrenia (TRS). To date, no studies have specifically analyzed CC morphology in TRS compared to healthy controls (HCs) and treatment-responsive SCZ patients (non-TRS). Methods: The study included 75 HCs and 97 SCZ patients (39 TRS and 58 non-TRS, including cannabis users and non-users). Participants underwent cross-sectional assessment using the Neurological Evaluation Scale (NES), the Brief Assessment of Cognition in Schizophrenia, and the Positive and Negative Syndrome Scale (PANSS). CC volume was measured via MRI and analyzed with a novel artificial intelligence program (MRI-AI) for single-subject assessment, with findings confirmed through group-level voxel-based morphometry (VBM). Results: TRS patients exhibited significantly higher total PANSS (p < 0.001) and NES (p < 0.001) scores and performed worse on working memory tasks compared to non-TRS patients. MRI-AI identified CC volume reduction in 55.88% of TRS patients (TRS CC: 3.02 mL vs. non-TRS with cannabis use: 3.69 mL; without cannabis use: 3.28 mL; p = 0.002). VBM confirmed significant CC volume reduction in TRS patients relative to HCs (p = 0.004). Cannabis use in non-TRS patients did not significantly affect CC volume or cognitive performance. Conclusions: TRS is associated with pronounced neurological, cognitive, and clinical dysfunctions. Aberrant CC volume may contribute to TRS pathogenesis and executive function deficits. MRI-AI provides a robust, single-subject approach for characterizing CC abnormalities in schizophrenia, offering potential for personalized clinical assessment. other: Future studies should explore longitudinal CC changes to evaluate whether they can be considered a potential biomarker for TRS. The potential of MRI-AI for single-subject analysis has provided encouraging results but should be further validated on larger samples.

Background/Objectives: The purpose of this study was to identify the most effective MRI techniques for detecting and characterising neck paragangliomas (NPGLs), which are highly vascularised tumors. Methods: Five readers were asked which MRI sequence among T2-WI, contrast-enhanced fat-suppressed T1-WI, pcASL, and TRICKS made them most confident in diagnosing paraganglioma. To evaluate concordance among the readers, the Fleiss K value was calculated. Sensitivity, specificity, and negative predictive values were calculated for each observer separately, and from all values, a mean was calculated. Results: The final cohort consisted of 28 patients (11 diagnosed with head-and-neck paragangliomas (HNPGLs)) of whom 7 were histologically confirmed and 4 identified based on a positive family history; 11 patients were undergoing familial screening (8 with HNPGLs and 3 without), and 6 patients had surgically confirmed vagal schwannomas. None of the schwannomas showed any increase in signal on pcASL sequences or arterial enhancement on TRICKS acquisition. The best concordance among readers was reached for pcASL and combined pcASL-TRICKS images (K = 1). Conclusions: The combined use of pcASL and TRICKS should be considered essential in a standardised protocol for characterising NPGLs.

The glycosylphosphatidylinositol (GPI) is a glycol–lipid that anchors several proteins to the cell surface. The GPI-anchor pathway is crucial for the correct function of proteins involved in cell function, and it is fundamental in early neurogenesis and neural development. The PIG gene family is a group of genes involved in this pathway with six genes identified so far, and defects in these genes are associated with a rare inborn metabolic disorder manifesting with a spectrum of clinical phenotypes in newborns and children. Among them, the PIGO gene encodes for phosphatidylinositol glycan anchor biosynthesis class O protein (PIGO), an enzyme participating in this cascade, and the loss of its function often leads to a severe clinical picture characterized by global developmental delay, seizures, Hirschsprung disease, and other congenital malformations. To date, 19 patients with confirmed PIGO deficiency have been described in the literature with a host of clinical and radiological manifestations. We report a case of a male term newborn with two compound heterozygous variants of the PIGO genes, presenting with encephalopathy, drug-resistant epilepsy, and gastrointestinal abnormalities. Brain MRI first showed diffusion restriction in the ponto-medullary tegmentum, ventral mesencephalon, superior cerebellar peduncles, cerebral peduncles, and globi pallidi. This pattern of lesion distribution has been described as part of the neuroradiological spectrum of PIG genes-related disorders. However, after one month of life, he also showed a previously undescribed MRI pattern characterized by extensive cortical and subcortical involvement of the brain hemispheres. The presence of two different mutations in both the PIGO genes may have been responsible for the particularly severe clinical picture and worse outcome, leading to the death of the newborn in the sixth month of life despite therapeutic attempts. This case expands the neuroradiological spectrum and may bring new insights on glycosylation-related disorders brain manifestations.

Objectives: To discriminate between post-treatment changes and tumor recurrence in patients affected by glioma undergoing surgery and chemoradiation with a new enhancing lesion is challenging. We aimed to evaluate the role of ASL, DSC, DCE perfusion MRI, and 18F-DOPA PET/CT in distinguishing tumor recurrence from post-treatment changes in patients with glioma.Materials and methods: We prospectively enrolled patients with treated glioma (surgery plus chemoradiation) and a new enhancing lesion doubtful for recurrence or post-treatment changes. Each patient underwent a 1.5T MRI examination, including ASL, DSC, and DCE PWI, and an¹⁸F-DOPA PET/CT examination. For each lesion, we measured ASL-derived CBF and normalized CBF, DSC-derived rCBV, DCE-derived Ktrans, Vp, Ve, Kep, and PET/CT-derived SUV maximum. Clinical and radiological follow-up determined the diagnosis of tumor recurrence or post-treatment changes.Results: We evaluated 29 lesions (5 low-grade gliomas and 24 high-grade gliomas); 14 were malignancies, and 15 were post-treatment changes.CBF ASL, nCBF ASL, rCBV DSC, and PET SUVmax were associated with tumor recurrence from post-treatment changes in patients with glioma through an univariable logistic regression.Whereas the multivariable logistic regression results showed only nCBF ASL (p = 0.008) was associated with tumor recurrence from post-treatment changes in patients with glioma with OR = 22.85, CI95%: (2.28–228.77).Conclusion: In our study, ASL was the best technique, among the other two MRI PWI and the 18F-DOPA PET/CT PET, in distinguishing disease recurrence from post-treatment changes in treated glioma.

Cranial nerve enhancement is a common and challenging MRI finding that requires a meticulous and systematic evaluation to identify the correct diagnosis. Literature mainly describes the various pathologies with the associated clinic-radiological characteristics, while the radiologist often needs a reverse approach that starts from the radiological findings to reach the diagnosis. Therefore, our aim is to provide a new and practical pattern-based approach to cranial nerve enhancement, which starts from the radiological findings and follows pattern-driven pipelines to navigate through multiple differential diagnoses, guiding the radiologist to reach the proper diagnosis. Firstly, we reviewed the literature and identified four patterns to categorize the main pathologies presenting with cranial nerve enhancement: unilateral linear pattern, bilateral linear pattern, unilateral thickened pattern, and bilateral thickened pattern. For each pattern, we describe the underlying pathogenic origin, and the main radiological features are displayed through high-quality MRI images and illustrative panels. A suggested MRI protocol for studying cranial nerve enhancement is also provided. In conclusion, our approach for cranial nerve enhancement aims to be an easy tool immediately applicable to clinical practice for converting challenging findings into specific pathological patterns.

Stereotactic radiosurgery (SRS) has transformed the management of brain metastases by achieving local tumor control, reducing toxicity, and minimizing the need for whole-brain radiation therapy (WBRT). This review specifically investigates radiation-induced changes in patients treated for metastasis, highlighting the crucial role of magnetic resonance imaging (MRI) in the evaluation of treatment response, both at very early and late stages. The primary objective of the review is to evaluate the most effective imaging techniques for assessing radiation-induced changes and distinguishing them from tumor growth. The limitations of conventional imaging methods, which rely on size measurements, dimensional criteria, and contrast enhancement patterns, are critically evaluated. In addition, it has been investigated the potential of advanced imaging modalities to offer a more precise and comprehensive evaluation of treatment response. Finally, an overview of the relevant literature concerning the interpretation of brain changes in patients undergoing immunotherapies is provided.

The 2021 WHO (World Health Organization) classification of brain tumors incorporated the rapid advances in the molecular, genetic, and pathogenesis understanding of brain tumor pathogenesis, behavior, and treatment response. It revolutionized brain tumor classification by placing great emphasis on molecular types and completely splitting adult-type and pediatric-type diffuse gliomas. Brainstem gliomas (BSGs) are the leading primary tumors of the brainstem, although they are quite uncommon in adults compared with the pediatric population, representing less than 2% of adult gliomas. Surgery is not always the treatment of choice since resection is rarely feasible and does not improve overall survival, and biopsies are not generally performed since the location is treacherous. Therefore, MRI (Magnetic Resonance Imaging) without and with gadolinium administration represents the optimal noninvasive radiological technique to suggest brainstem gliomas diagnosis, plan a multidisciplinary treatment and for follow-up evaluations. The MRI protocol encompasses morphological sequences as well as functional and advanced sequences, such as DWI/ADC (Diffusion-Weighted Imaging/Apparent Diffusion Coefficient), DTI (Diffusion Tensor Imaging), PWI (Perfusion-Weighted Imaging), and MRS (Magnetic Resonance Spectroscopy), which improve the accuracy of the diagnosis of BSGs by adding substantial information regarding the cellularity, the infiltrative behavior toward the v fiber tracts, the vascularity, and the molecular changes. Brainstem gliomas have been divided into four categories on the basis of their MRI radiological appearance, including diffuse intrinsic low-grade gliomas, enhancing malignant gliomas, localized tectal gliomas, and other forms. The aim of our review is to provide insight into the role of advanced MRI sequences in the diagnosis and follow-up of adult brainstem gliomas.