Imaging of Subdural Hematomas

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.

Rosai–Dorfman disease mimicking subdural hematoma: a case report

Rosia–Dorfman disease (RDD) is a rare benign disease with exceedingly rare neural involvement. In this report, we describe a very rare case of intracranial RDD mimicking a subdural hematoma. The patient presented with headache and a suspected history of head injury. Head computed tomography showed a well-demarcated extra-axial crescentic hyperdense lesion along the right hemisphere convexity, and this lesion was initially mistaken for a subacute subdural hematoma with brain contusion. However, the follow-up examinations during the subsequent month did not show the natural changes characteristic of a subdural hematoma. Thus, a magnetic resonance imaging scan was performed, which showed a crescentic lesion with T1 isointensity, T2 hypointensity, and obvious homogeneous enhancement. Differential diagnoses such as lymphoma and metastases were considered, and surgery was performed. The final histopathologic examination confirmed the diagnosis of RDD. This report describes a rare presentation of RDD. RDD can mimic the appearance of a subdural hematoma and should be considered as a differential diagnosis even in patients with a history of head injury and a “classic” imaging appearance of a subdural hematoma.

Traumatic acute subdural hematoma and coma: retrospective cohort of surgically treated patients

BACKGROUND

A subdural hematoma is defined as clot formation in the subdural space after vessel rupture or brain parenchyma damage. Several demographic and tomographic factors were associated to poor prognosis, although some debate according to their specific roles still remains.

METHODS

Retrospective cohort study of comatose patients admitted to a single-institution, tertiary hospital center, between the years 2013 and 2019 with traumatic acute subdural hematoma requiring surgical evacuation were studied. Demographic and tomographic data were obtained from medical records. Univariate and multivariate statistical analysis were performed, using a value of P < 0.05 for significance.

RESULTS

Seventy-seven patients were selected using the criteria and a total of 37 (48%) head CT exams were evaluated. The overall mortality was 57.1% and achieved 100% at ≥75-years-old subgroup. Univariate analysis only found young age as a good prognosis factor (P = 0.002). Gender (P = 0.784), abnormal pupillary response (P = 0.643), midline shift (P = 0.874), clot thickness (P = 0.206), compressed basal cisterns (P = 0.643), hematoma side (P = 0.879), and subarachnoid hemorrhage (P = 0.510) showed no association. Multivariate analysis showed no statistically significant association between covariates.

CONCLUSION

Traumatic acute subdural hematoma is a life-threatening condition. Younger age was the only positive prognostic factor identified. More research is necessary to establish age as a rule-out criterion to surgical indication.

Heterogeneity of acute subdural collections: In search of a unifying feature

Introduction

A variety of different acute subdural hematoma patterns of density have been reported in the literature and are commonly seen in clinical practice, including rare hypodense acute subdural hematomas. It is unclear if these acute hypodense collections are entirely hypodense or if on close inspection, they can reveal subtle, tiny hyperdense components. The purpose of this study was to determine if all acute subdural hemtomas contain a hyperdense component, including seemingly entirely hypodense subdural collections.

Methods

Non-contrast CT scans of 111 patients containing 320 hyperacute or acute subdural collections were analyzed for the presence of a hyperdense component. Hounsfield measurements were recorded.

Results

All hyperacute and acute subdural hematomas in our study had a hyperdense component. Hyperacute subdural hematomas have a hyperdense component >97.5% of the time (95% confidence), and acute subdural hematomas have a hyperdense component >99% of the time (95% confidence).

Conclusion

Lack of a hyperdense component in a subdural hematoma makes acute or hyperacute hematoma highly unlikely, and alternative diagnoses should be considered.

Risk-assessment in chronic subdural hematoma evaluated in 148 patients - A score for predicting recurrence

BACKGROUND

Chronic subdural hematoma (CSDH) is a frequent disease in neurosurgical practice. However, a considerable recurrence rate keeps this condition challenging to treat. We aimed to provide a simple tool for risk assessment in these patients.

METHODS

We conducted a retrospective analysis of surgically treated patients with chronic subdural hematomas. In addition to patients' demographics, radiological assessment included volume, thickness, midline shift and density of hematomas. Statistically significant variables in univariate analysis were further analyzed in a multivariate logistic regression model to create a risk score for recurrence of CSDH.

RESULTS

A total of 148 patients were identified and included for analysis. 50.7 % (n = 75) were older than 76 years of age. The overall hematoma recurrence rate requiring surgery was 23.6 % (n = 35). Preoperative thrombocytopenia, postoperative midline shift >6 mm, hematoma volume >80 mL and overall hematoma density >45 Hounsfield Units (HU), were significantly more frequent in the recurrence group. Furthermore, after multivariate assessment, postoperative hematoma density and volume were independent risk factors and included in the risk assessment tool. Patients were divided into 3 risk groups corresponding to the total scores.

CONCLUSION

We provide a risk-score assessment for predicting recurrence of subdural hematoma. The risk-score comprises postoperative hematoma volume and density. This tool could ease decision making in follow-up evaluation and indication for recurrence surgery. Yet, further prospective evaluation is required to assess the clinical value of this tool.

Susceptibility weighted imaging at 1.5 Tesla magnetic resonance imaging in dogs: Comparison with T2*-weighted gradient echo sequence and its clinical indications

Susceptibility weighted imaging (SWI) is a high resolution, fully velocity-compensated, three-dimensional gradient echo (GE) MRI technique. In humans, SWI has been reported to be more sensitive than T2*-weighted GE sequences in the identification of both intracranial hemorrhage and intra-vascular deoxyhemoglobin. However, published clinical studies comparing SWI to T2*-weighted GE sequences in dogs are currently lacking. The aim of this retrospective, observational study was to compare SWI and T2*-weighted GE sequences in a group of dogs with intracranial disease. Medical records were searched for dogs that underwent a brain MRI examination that included T2*-weighted GE and SWI sequences. The presence and appearance of non-vascular and vascular signal voids observed on T2*-weighted GE and SWI were compared. Thirty-two dogs were included with the following diagnoses: presumed and confirmed intracranial neoplasia (27), cerebrovascular accidents (3), and trauma (2). Hemorrhagic lesions were significantly more conspicuous on SWI than T2*-weighted GE sequences (P < .0001). Venous structures were well defined in all SWI sequences, and poorly defined in all dogs on T2*-weighted GE. Susceptibility weighted imaging enabled identification of vascular abnormalities in 30 of 32 (93.8%) dogs, including: neovascularization in 19 of 32 (59.4%) dogs, displacement of perilesional veins in five of 32 (15.6%) dogs, and apparent dilation of perilesional veins in 10 of 32 (31.3%) dogs. Presence of neovascularization was significantly associated with T1-weighted post-contrast enhancement (P = .0184). Hemorrhagic lesions and venous structures were more conspicuous on SWI compared to T2*-weighted GE sequences. Authors recommend adding SWI to standard brain protocols in dogs for detecting hemorrhage and identifying venous abnormalities for lesion characterization.

Subdural haematoma mimics

A subdural haematoma (SDH) is a frequently encountered pathology seen on an emergency room computed tomography (CT) head scan. An extra-axial crescentic density along the convexity of the brain or within the interhemispheric fissure is generally thought to represent a SDH; however, SDH mimics are known to occur in nature, and can be broadly classified under the subcategories of normal anatomy, artefacts, tumour, inflammation, infection, ischaemia, trauma, and iatrogenic. Understanding the typical characteristics of a SDH, knowledge of normal anatomy, close inspection of the morphology of the subdural process, changes to the adjacent structures, and rigorous attention to clinical details may reveal subtle clues that distinguish a true SDH from a mimic. This is crucial in appropriately directing clinical management. This review amalgamates most of the rare subdural processes that have been reported to mimic SDH, and discusses the imaging and clinical features that help to differentiate between them. This topic is highly valuable for radiology trainees, general radiologists, and emergency room physicians, and may serve as a refresher for the practising neuroradiologist.

Italian consensus conference on guidelines for conservative treatment on lower limb muscle injuries in athlete

Provide the state of the art concerning (1) biology and aetiology, (2) classification, (3) clinical assessment and (4) conservative treatment of lower limb muscle injuries (MI) in athletes. Seventy international experts with different medical backgrounds participated in the consensus conference. They discussed and approved a consensus composed of four sections which are presented in these documents. This paper represents a synthesis of the consensus conference, the following four sections are discussed: (i) The biology and aetiology of MIs. A definition of MI was formulated and some key points concerning physiology and pathogenesis of MIs were discussed. (ii) The MI classification. A classification of MIs was proposed. (iii) The MI clinical assessment, in which were discussed anamnesis, inspection and clinical examination and are provided the relative guidelines. (iv) The MI conservative treatment, in which are provided the guidelines for conservative treatment based on the severity of the lesion. Furthermore, instrumental therapy and pharmacological treatment were discussed. Knowledge of the aetiology and biology of MIs is an essential prerequisite in order to plan and conduct a rehabilitation plan. Another important aspect is the use of a rational MI classification on prognostic values. We propose a classification based on radiological investigations performed by ultrasonography and MRI strongly linked to prognostic factors. Furthermore, the consensus conference results will able to provide fundamental guidelines for diagnostic and rehabilitation practice, also considering instrumental therapy and pharmacological treatment of MI. Expert opinion, level IV.