Twenty classic signs in neuroradiology: A pictorial essay

The "White Cerebellum Sign", a Striking Computed Tomography Scan Finding in a Critically Ill Infant: A Case Report

The "white cerebellum sign" is a striking neuroradiological finding, resulting from diffuse hypodense brain lesions in both cerebral hemispheres while sparing the cerebellum. This indicates widespread ischemic damage or expanded cerebral edema associated with the loss of white-gray matter differentiation. It is commonly reported in pediatric cases with severe neurological conditions, usually resulting in a poor prognosis. We present a case of a three-month-old female infant who was managed for confirmed acute bacterial meningitis complicated by status epilepticus, where the Computed tomography scan (CT scan) showed the "white cerebellum sign" in relation to diffuse cerebral hypoxic-ischemic lesions. However, the patient had a favorable outcome following treatment. This case underscores the importance of early recognition in cases presenting with the "white cerebellum sign". It highlights the potential for a positive prognosis even in severe neurological conditions when appropriate interventions are promptly administered.

Venous Pathologies and Interventions of the Head

Intracranial venous pathologies are a historically underrecognized group of disorders that can have a devastating impact on patients. Despite advancements in peripheral venous disorders and arterial neurointerventions, intracranial venous pathologies have received comparatively little attention. Understanding the anatomy, physiology, clinical relevance, and treatment options of intracranial venous pathologies is fundamental to evolving therapies and research priorities. This article provides an overview of major intracranial venous pathologies, the respective pathophysiologies, and treatment options.

Case report: The origin of transmantle-like features

The transmantle sign is considered to be a magnetic resonance imaging feature specific to patients with type II focal cortical dysplasia; however, this sign can be difficult to distinguish from other pathologies, such as a radial-oriented white matter band in tuberous sclerosis. Here, we report a case showing a high-intensity area on T2-weighted and fluid-attenuated inversion recovery images extending from the ventricle to the cortex associated with atypical histopathological findings containing corpora amylacea. This case demonstrates that some instances of transmantle signs may be due to corpora amylacea accumulation.

MRI signs of CNS demyelinating diseases

The differential diagnosis of the central nervous system (CNS) demyelinating diseases can be greatly facilitated by visualization and appreciation of pathognomonic radiological signs, visualized on magnetic resonance imaging (MRI) sequences. Given the distinct therapeutic approaches for each of these diseases, a decisive and reliable diagnosis in patients presenting with demyelination-associated symptoms is of crucial value. Multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) are major examples of such conditions, each possessing a number of MRI signs, closely associated with the disorder. This pictorial review aims to describe seventeen pathognomonic MRI signs associated with several CNS demyelinating disorders including MS, NMOSD, myelin oligodendrocyte glycoprotein-associated disease, Baló's concentric sclerosis, metachromatic leukodystrophy, progressive multifocal leukoencephalopathy, and neurosarcoidosis.

Pictorial Essay: Classic Signs in Pediatric Neuroradiology

BACKGROUND

A number of metaphorical imaging signs have been described in the radiology literature.

OBJECTIVE

These signs not only make the learning process easier but also increase diagnostic confidence. For this reason, these signs are quite popular among radiologists.

CONCLUSION

In this article, we have demonstrated classic signs described in pediatric neuroradiology with appropriate examples and illustrations.

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.

Early signs of middle cerebral artery infarction on multidetector computed tomography: Review of 20 cases

OBJECTIVE

This study intended to assess the occurrence of early signs of middle cerebral artery (MCA) on multidetector computed tomography (MDCT) in correlation with duration of the clinical features of stroke.

PATIENTS AND METHODS

This retrospective study analyzed the electronic records of 20 patients with MCA infarction. The detected signs studied according to the onset of the clinical features of stroke to the time of CT imaging.

RESULTS

Out of 20 patients with MCA infarction included in this study, the results revealed a significant relationship between the presence of insular ribbon sign and/or subtle hypodensity and hyperacute infarction (P < 0.001 and 0.003, respectively). Results revealed significant relationship between the occurrence of hypodense area, effacement of the cortical sulci, and compression of the ipsilateral lateral ventricle with acute infarction (6-72 h), (P = 0.006, 0.007, and 0.002) (odds ratio = 0.047, 0.050 and 0.028) and (95% confidence interval = 0.004-0.552, 0.004-0.597 and 0.002-0.367) respectively.

CONCLUSION

MDCT can detect nearly half of MCA infarctions in the first 6 h. Insular ribbon sign and subtle hypodensity were the most significant findings in the first 6 h of stroke. Hypodense area was a significant sign after 6 h. Diabetes mellitus and ischemic heart disease were the most common risk factors. Hemiparesis was the most common clinical finding in MCA infarction.

The Clinical Application of Fluorescence-Guided Surgery in Head and Neck Cancer

Although surgical resection has been the primary treatment modality of solid tumors for decades, surgeons still rely on visual cues and palpation to delineate healthy from cancerous tissue. This may contribute to the high rate (up to 30%) of positive margins in head and neck cancer resections. Margin status in these patients is the most important prognostic factor for overall survival. In addition, second primary lesions may be present at the time of surgery. Although often unnoticed by the medical team, these lesions can have significant survival ramifications. We hypothesize that real-time fluorescence imaging can enhance intraoperative decision making by aiding the surgeon in detecting close or positive margins and visualizing unanticipated regions of primary disease. The purpose of this study was to assess the clinical utility of real-time fluorescence imaging for intraoperative decision making. Methods: Head and neck cancer patients (n = 14) scheduled for curative resection were enrolled in a clinical trial evaluating panitumumab-IRDye800CW for surgical guidance (NCT02415881). Open-field fluorescence imaging was performed throughout the surgical procedure. The fluorescence signal was quantified as signal-to-background ratios to characterize the fluorescence contrast of regions of interest relative to background. Results: Fluorescence imaging was able to improve surgical decision making in 3 cases (21.4%): identification of a close margin (n = 1) and unanticipated regions of primary disease (n = 2). Conclusion: This study demonstrates the clinical applications of fluorescence imaging on intraoperative decision making. This information is required for designing phase III clinical trials using this technique. Furthermore, this study is the first to demonstrate this application for intraoperative decision making during resection of primary tumors.

Signs in Neuroradiology: A Pictorial Review

One of the major problems radiologists face in everyday practice is to decide the correct diagnosis, or at least narrow down the list of possibilities. In this context, indicative evidences (signs) are useful to recognize pathologies, and also to narrow the list of differential diagnoses. Despite classically being described for a single disease, or a closely related family of disorders, most indications are not restricted exclusively to their traditional definition. Therefore, using signs for prognosis requires knowledge of the mechanism of their appearance, and which pathologies they are observed in. In this study, we demonstrate some of the more common and useful neuroradiologic signs with relevant images, and discuss their use in differential diagnosis.

Imaging in Juvenile Nasopharyngeal Angiofibroma: Clinical Significance of Ramharan and Chopstick Sign

Imaging plays an important role in the diagnosis, staging and prognosis of JNA. Certain radiological changes as seen on CECT were observed to be consistent in our case series. This study analysed preoperative and postoperative CECT of large series of JNA patients to evaluate the sites and pattern of spread of tumor. We evaluated the clinical significance of pterygoid wedge in preoperative and postoperative imaging and thus elucidating two new radiological signs. Retrospective analysis of the pre operative and post operative imaging data of 242 patients with JNA. The findings in the scan were clinically correlated with the endoscopic intraoperative findings. Preoperative evaluation of the pterygoid wedge revealed widening on the involved side in 99.1% of our cases which is 1.8 times greater compared to the uninvolved side. The possibility of residual/recurrent tumor was found to be significantly higher in those where the pterygoid wedge was not removed by drilling (p < 0.001) Drilling of the pterygoid wedge intra operatively, reduced the rate of residual/recurrence from 31.9 to 3.07%. Widening of the pterygoid wedge seen in the preoperative CECT, referred as RAM HARAN sign occurs in JNA. It has a significant diagnostic value as a radiological sign in JNA. Drilling of the pterygoid wedge intraoperatively reduces the rate of recurrence of JNA. Appearance of the two pterygoid plates on postoperative CECT, as two parallel lines, referred as Chopstick sign, has a remarkable prognostic value as a radiological sign in JNA.

Hyperdense Middle Cerebral Artery Sign Together with Pulmonary Thromboembolism

Background

Hyperdense middle cerebral artery sign is an appearance of the middle cerebral artery on non-contrast-enhanced computed tomography. Embolic occlusion of the pulmonary arterial system is referred to as pulmonary embolism. When pulmonary embolism coexists with a patent foramen ovale, increased pressure in the right atrium may result in widening of the foramen and consequently, cause serious conditions due to paradoxical embolus. Coexistence of hyperdense middle cerebral artery sign and pulmonary thromboembolism is very rare in the literature.

Case Report

We presented a 60-year-old female patient who had both hyperdense middle cerebral artery sign and pulmonary thromboembolism.

Conclusions

To our knowledge, togetherness of hyperdense MCA sign and pulmonary thromboembolism is extremely rare in the literature. In our case, we found both pulmonary embolism due to DVT and paradoxical embolism due to existing patent foramen ovale.

Lisch and the Importance of His Nodules

Neurofibromatosis 1 is the commonest neurocutaneous autosomal dominant disorder with full penetrance, although expression may not be complete by the age of five years. Lisch nodules, however, are predominantly visible in children usually after the age of six years. Therefore, it is important to appreciate that their absence before this age does not pre-empt the diagnosis. A child being treated for hypertension of unknown aetiology with cafe au lait lesions presented to the ophthalmologist with blurred vision. Clinical examination revealed Lisch nodules which confirmed the suspicion of neurofibromatosis 1 as per National Institutes of Health criteria. The aim of this report is to highlight the importance of regular ophthalmic screening, both in suspected and confirmed cases, as these patients have long-term sequelae.

Classical signs and appearances in pediatric neuroradiology: a pictorial review

Radiological practice includes classification of illnesses with similar characteristics through recognizable signs. In this report, twenty-eight important and frequently seen neuroradiological signs in childhood are presented and described using X-rays, computed tomography (CT), magnetic resonance (MR) images, illustrations and photographs.

Neurodegeneration with Brain Iron Accumulation: Clinicoradiological Approach to Diagnosis

Discovery of genetic abnormalities associated with neurodegeneration with brain iron accumulation (NBIA) has led to use of a genetic-based NBIA classification schema. Most NBIA subtypes demonstrate characteristic imaging abnormalities. While clinical diagnosis of NBIA is difficult, analysis of both clinical findings and characteristic imaging abnormalities allows accurate diagnosis of most of the NBIA subtypes. This article reviews recent updates in the genetic, clinical, and imaging findings of NBIA subtypes and provides a practical step-by-step clinicoradiological algorithm toward clinical diagnosis of different NBIA subtypes.

Integration of imaging signs into RadLex

Imaging signs form an important part of the language of radiology, but are not represented in established lexicons. We sought to incorporate imaging signs into RSNA's RadLex® ontology of radiology terms. Names of imaging signs and their definitions were culled from books, journal articles, dictionaries, and biomedical web sites. Imaging signs were added into RadLex as subclasses of the term "imaging sign," which was defined in RadLex as a subclass of "imaging observation." A total of 743 unique imaging signs were added to RadLex with their 392 synonyms to yield a total of 1,135 new terms. All included definitions and related RadLex terms, including imaging modality, anatomy, and disorder, when appropriate. The information will allow RadLex users to identify imaging signs by modality (e.g., ultrasound signs) and to find all signs related to specific pathophysiology. The addition of imaging signs to RadLex augments its use to index the radiology literature, create and interpret clinical radiology reports, and retrieve relevant cases and images.