Limitations of T2*-Gradient Recalled-Echo and Susceptibility-Weighted Imaging in Characterizing Chronic Subdural Hemorrhage in Infant Survivors of Abusive Head Trauma

Intracranial Subdural Fluid Accumulation Associated with a Choroid Plexus Carcinoma in a Dog

Choroid plexus tumors are commonly described as intraventricular mass lesions and account for 7-10% of intracranial, primary tumors in dogs. A 3-year-old Shetland sheepdog was presented with a history of slowly progressive lethargy, vision impairment and cognitive deficits. On magnetic resonance imaging, a subdural fluid accumulation (SFA) overlying and compressing the left parietotemporal lobe as well as multifocal changes consisting of cyst-like lesions, supposed intra-axial brain lesions and mild, multifocal meningeal thickening and generalized contrast enhancement were identified. Cerebrospinal fluid (CSF) analysis showed a mononuclear pleocytosis with negative results for infectious agents. The dog was treated with prednisolone followed by burr hole craniotomy with puncture of the SFA, which macroscopically appeared to be CSF-like fluid. After initial improvement, the dog deteriorated despite continuation of prednisolone and cytarabine therapy and was euthanized four weeks after surgery. Histopathology was consistent with a disseminated, neuroinvasive choroid plexus carcinoma (CPC) that involved the entire neuroaxis including the meninges of the brain and spinal cord. Immunohistochemical examination showed a strong Kir7.1 and a heterogenous cytokeratin-immunoreactivity in neoplastic cells. In conclusion, a CPC should be considered as a possible cause of a SFA even in the absence of an intraventricular mass lesion.

MRI appearance of chronic subdural hematoma

Objective

We aimed to describe the magnetic resonance imaging (MRI) characteristics of chronic subdural hematoma (cSDH) and to ascribe MRI patterns.

Methods

A total of 20 patients having 27 subdural hematomas underwent contrast-enhanced (CE) MRI of the brain at our institution between April 2019 and May 2021. The images were independently evaluated by two experienced neuroradiologists with regard to imaging characteristics on T1w, T2w, T2*-GRE, FLAIR, diffusion-weighted magnetic resonance imaging (DWI), and CE images.

Results

The signal characteristics of cSDH on T1- and T2-weighted images were rather heterogeneous. The majority of hematomas (74%) had internal septations. Surprisingly, contrast enhancement along the outer membrane adjacent to the cranium was noticed in all hematomas. There was also contrast enhancement along the inner membrane adjacent to the brain in more than one-third of the hematomas (37%). In approximately two-thirds of the cSDH (62%), there was a mass-like enhancement of the hematoma. Most hematomas (89%) were partially hypointense on T2*-GRE and/or susceptibility-weighted imaging (SWI). Restricted diffusion was detected in approximately one-third of the hematomas (33%).

Conclusion

Consistent contrast enhancement along the outer membrane, triangular-shaped contrast enhancement at the borders of the cSDH, and infrequent enhancement of the inner membrane may help to distinguish cSDH from other entities such as empyema and tumors. Mass-like enhancement may refer to non-solid hematomas and could be an indicator for hematoma growth and a possible surrogate for successful endovascular embolization. Restricted diffusion in a subdural mass is not specific for empyema but may also be found in cSDH.

Susceptibility-weighted Imaging in Neuroradiology: Practical Imaging Principles, Pearls and Pitfalls

Susceptibility-weighted imaging (SWI) was one of the recent and helpful advancement in magnetic resonance imaging. Its utilization -provided valuable information for the radiologists in multiple fields, including neuroradiology. SWI was able to demonstrate cerebral paramagnetic and diamagnetic substances. Therefore, the applications of this imaging technique were diverse in research and clinical neuroradiology. This article reviewed the basic technical steps, various clinical applications of SWI, and potential limitations. The practicing radiologist needs to be oriented about using SWI and phase images in the right- and left-handed MRI systems to demonstrate different brain pathologies, including neurovascular diseases, traumatic brain injuries, brain tumors, infectious and inflammatory, and neurodegenerative diseases.

Understanding Subdural Collections in Pediatric Abusive Head Trauma

Life-threatening physical abuse of infants and toddlers is frequently correlated with head injuries. A common variant of the abusive head trauma is the shaken baby syndrome. The present review article sheds light on subdural collections in children with abusive head trauma and aims at providing a recent knowledge base for various medical disciplines involved in diagnostic procedures and legal proceedings. To this end, the different subdural collection entities are presented and illustrated. The pathophysiologic background is explained. Differential and age-diagnostic aspects are discussed and summarized by tabular and graphic overviews. Two problematic constellations frequently occurring during initial CT investigations are evaluated: A mixed-density subdural collection does not prove repeated trauma, and hypodense subdural collections are not synonymous with chronicity. The neuroradiologic analysis and assessment of subdural collections may decisively contribute to answering differential diagnostic and forensic questions. In addition to more reference data, a harmonization of terminology and methodology is urgently needed, especially with respect to age-diagnostic aspects.