Extra-axial cranial nerve enhancement: a pattern-based approach.

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.

Giant serpentine aneurysm: Neuroradiological and neurosurgical management in a left-handed patient.

Giant serpentine aneurysms are rare huge and partially thrombosed aneurysms, with an eccentric tortuous intra-aneurysmal vascular channel. Surgical treatment is often necessary due to the great mass effect. We describe a case of a left-handed woman with a giant serpentine aneurysm of the left middle cerebral artery whose management was complex. The challenge was to exclude the aneurysm from circulation, reduce the mass effect, and, mostly, preserve the language function. Since the patient was left-handed the language dominance needed to be assessed; functional MRI (fMRI) and Wada test (WT) showed a right dominance. Surgical treatment was performed, as a complication, the patient developed left fronto-basal ischemia with a slight paresis of the right hand but without any language deficit. Our case shows the importance of a multidisciplinary team in patient management, with a pivotal role of neuroradiological functional tests in presurgical planning.

Radiosurgery for Brain Metastases: Challenges in Imaging Interpretation after Treatment.

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.

Intradural abscess: A challenging diagnosis. Case series and review of the literature.

Spinal intradural abscesses are extremely rare. To our knowledge, only a few cases have been described in the literature. We report 2 cases of spinal intradural abscesses in patients presenting to our institution with different symptomatology. Both cases involved the lumbar spine, with different etiologies: Case 1 was presumptively related to spondylitis phenomena, with surgery confirming the intradural localization of the abscess; case 2 was of probable iatrogenic nature (secondary to lumbar drain positioning). The aim of this report is to briefly discuss the clinical significance and pathogenesis of these cases.

The Role of Advanced MRI Sequences in the Diagnosis and Follow-Up of Adult Brainstem Gliomas: A Neuroradiological Review.

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.

The impact of labyrinthine magnetic resonance signal alterations on the treatment of sudden sensory-neural hearing loss.

BACKGROUND: Sudden sensory-neural hearing loss (SSNHL), with positive findings on magnetic resonance imaging (MRI), possibly related to labyrinthine hemorrhage, is a rare condition and difficult to be diagnosed. OBJECTIVES: We evaluated the role of MRI in detecting labyrinthine signal changes and the impact of these changes on the prognosis of SSNHL after the intratympanic corticosteroid injection. METHODS: A prospective study was held between January and June 2022. We included patients who complained of SSNHL, either idiopathic (30 patients) or labyrinthine signal alterations (14 patients), as diagnosed by MRI performed 15 days after the SSNHL onset. In addition, all patients underwent a course of intratympanic prednisolone injections. RESULTS: 83.3% of the idiopathic group showed a complete or marked improvement after the intratympanic injection. Conversely, most cases of positive MR signal alterations (92.8%) had slight or poor improvement after the therapeutic course. CONCLUSIONS: Our study revealed that MRI imaging is essential for assessing any SSNHL case. It can diagnose labyrinthine hemorrhage, whose course and prognosis differ significantly from idiopathic SSNHL. SIGNIFICANCE: Intratympanic prednisolone injection was effective in managing idiopathic SSNHL. On the other hand, this therapeutic modality was ineffective in improving SSNHL associated with labyrinthine hemorrhage.

Dural Tail Sign and Middle Meningeal Artery Hypertrophy in Glioblastoma: A Rarity?

BACKGROUND: Dural tail sign and increased caliber of branches of the external carotid artery (ECA) are common findings in meningioma and they have been rarely reported in intra-axial lesions. Anyway, some cases of glioblastoma (GBM) are reported in the literature, mostly superficially localized, characterized by these 2 findings and therefore, misdiagnosed with meningioma. The aim of this study is to verify the prevalence of dural tail sign and hypertrophy of middle meningeal artery (MMA) in a large cohort of GBMs. METHODS: 180 GBM patients were retrospectively evaluated. Deep or superficial localization of GBM was established and the presence of dural tail sign and hypertrophy of the ipsilateral MMA were assessed. The rate of tumor necrosis and the incidence of dural metastases during the radiological follow-up were also evaluated. Inter-rater reliability was calculated using Cohen's K-test. RESULTS: Dural tail sign and enlarged MMA were evident in 30% and 19% of 96 superficial GBM, respectively. Deep GBM did not present those signs. Only one patient developed dural metastasis at follow-up and no differences in terms of tumor necrosis and hypoxic biomarkers expression were evident among GBMs with and without dural and vessel signs. CONCLUSIONS: Dural tail sign and hypertrophy of the MMA in superficial GBM are more common than expected. They probably represent reactive rather than a neoplastic infiltration. Knowing these radiological signs may be important in terms of neurosurgery planning and avoiding excessive bleeding. Anyway, this hypothesis should be confirmed by a prospective neurosurgery studio.

Diffusion Weighted Imaging in Neuro-Oncology: Diagnosis, Post-Treatment Changes, and Advanced Sequences-An Updated Review.

DWI is an imaging technique commonly used for the assessment of acute ischemia, inflammatory disorders, and CNS neoplasia. It has several benefits since it is a quick, easily replicable sequence that is widely used on many standard scanners. In addition to its normal clinical purpose, DWI offers crucial functional and physiological information regarding brain neoplasia and the surrounding milieu. A narrative review of the literature was conducted based on the PubMed database with the purpose of investigating the potential role of DWI in the neuro-oncology field. A total of 179 articles were included in the study.