Human pegivirus identified in severe myelitis and optic neuritis in immunocompromised patients: A pathogenic role for a forgotten virus?

The role of Human pegivirus (HPgV) in patients with encephalitis has been recently questioned. We present cases of 4 patients with similar clinical, biological, and radiological characteristics, including a past history of transplantation with long-term immunosuppression and a progressive course of severe and predominantly myelitis, associated in 3 cases with optic neuropathy causing blindness. Extensive workup was negative but analysis of the CSF by use of pan-microorganism DNA- and RNA-based shotgun metagenomics was positive for HPgV. This case series further supports the hypothesis of HPgV CNS infection and highlights the utility of metagenomic next-generation sequencing of CSF in immunocompromised patients.

Usefulness of colour Doppler flow imaging in the management of lacrimal gland lesions.

OBJECTIVE: To assess the role of colour Doppler flow imaging (CDFI) in the diagnosis and management of lacrimal fossa lesions. METHODS: Institutional ethical committee approval was obtained. Fifty-one patients with 62 lacrimal fossa lesions were retrospectively included from 2003-2015. All patients underwent conventional ultrasonography and CDFI, with a qualitative and quantitative analysis of the vascularization. All patients had lacrimal gland surgery. Definitive diagnosis was based on pathological examination. RESULTS: The study included 47 non-epithelial lesions (NEL) and 15 epithelial lesions (EL), with 24 (39 %) malignant lesions and 38 (61 %) benign lesions. NEL were significantly more likely to present with septa (p < 0.001), hypoechogenicity (p < 0.001), high vascular intensity (p < 0.001), both central and peripheral vascularization (p < 0.001), tree-shape vascularization (p < 0.05) and a low resistance index (RI) (p < 0.0001). EL were significantly more likely to present with the presence of cysts (p < 0.001), and a higher RI. Receiver operating characteristic curves identified a RI value of 0.72 as the best cut-off to differentiate NEL from EL, with a sensitivity and specificity of 100 %. CONCLUSION: CDFI is a valuable tool in the differential diagnosis of lacrimal fossa lesions. Resistance index measurement enables substantial distinction between EL and NEL, thus providing crucial data for surgical management. KEY POINTS: • CDFI is a valuable tool in lacrimal fossa lesions. • Resistance Index measurement enables substantial distinction between epithelial and non-epithelial lesions. • Management of patients becomes more appropriate.

[Orbito-palpebral vascular pathology]. / Pathologie vasculaire orbito-palpébrale.

Orbito-palpebral vascular pathology represents 10% of all the diseases of this area. The lesion may be discovered during a brain CT scan or MRI, or because it causes clinical symptoms such as orbital mass, visual or oculomotor alteration, pain, proptosis, or acute bleeding due to a complication of the lesion (hemorrhage, thrombosis). We present these lesions using an anatomical, clinical, imaging and therapeutic approach. We distinguish four different entities. Vascular tumors have common imaging characteristics (hypersignal on T2 sequence, contrast enhancement, abnormal vascularization well depicted with ultrasound and Doppler, and possible bleeding). The main lesions are cavernous hemangiomas, the most frequent lesion of that type during adulthood; infantile hemangiomas, the most frequent vascular tumor in children; and more seldomly, hemangioperitcytomas. True vascular malformations are divided according to their flow. Low flow lesions are venous (orbital varix), capillarovenous or lymphatic (lymphangioma). High flow malformations, more rare, are either arteriovenous or arterial malformations (aneurisms). Complex malformations include both low and high flow elements. Lesions leading to modifications of the orbito-palpebral blood flow are mainly due to cavernous sinus abnormalities, either direct carotid-cavernous fistula affecting young adults after severe head trauma, or dural fistula, more insidious, found in older adults. The last section is devoted to congenital syndromic vascular malformations (Sturge-Weber, Rendu-Olser…). This classification allows for a better understanding of these pathologies and their specific imaging features.

Open-angle glaucoma and paraoptic cyst: first description of a series of 11 patients.

We report 11 patients who were referred to our institution for severe open-angle glaucoma who had a paraoptic cyst on MR imaging. All cysts were extraoptic and retrolaminar; most were deforming the adjacent optic nerve. Cysts had a high signal on T2 and FLAIR sequences, and a variable signal on T1 and variable echogenicity, suggesting different proteinaceous content. Arterial vascularization of the optic nerve was normal. Cyst volumes were inversely correlated with the severity of glaucoma on the same eye (P < .01-.05, Spearman correlation coefficient). We hypothesized that such cysts may reflect a valve mechanism, which would allow preservation of the translamina cribrosa pressure and thus could preserve visual function. The rarity of this association, together with the frequent mass effect of the cyst on the optic nerve, stresses the necessity of long-term follow-up in these patients.

Tumor pathology of the orbit.

The term orbital tumor covers a wide range of benign and malignant diseases affecting specific component of the orbit or developing in contact with them. They are found incidentally or may be investigated as part of the assessment of a systemic disorder or because of orbital signs (exophthalmos, pain, etc.). Computed tomography, MRI and Color Doppler Ultrasound (CDU), play a varying role depending on the clinical presentation and the disease being investigated. This article reflects long experience in a reference center but does not claim to be exhaustive. We have chosen to consider these tumors from the perspective of their usual presentation, emphasizing the most common causes and suggestive radiological and clinical presentations (progressive or sudden-onset exophthalmos, children or adults, lacrimal gland lesions, periorbital lesions and enophthalmos). We will describe in particular muscle involvement (thyrotoxicosis and tumors), vascular lesions (cavernous sinus hemangioma, orbital varix, cystic lymphangioma), childhood lesions and orbital hematomas. We offer straightforward useful protocols for simple investigation and differential diagnosis. Readers who wish to go further to extend their knowledge in this fascinating area can refer to the references in the bibliography.

No more fear of the cavernous sinuses!

After a review of the anatomy of the cavernous sinuses (CS), this work presents the clinical picture and imaging protocol of lesions which occur in this area. It outlines extension and imaging features of these lesions. It emphasises MRI appearance, such as T1, T2 and diffusion signal, type of contrast medium uptake. A complementary CT scan is performed if an associated abnormality of the base of the skull is suspected on MRI (lysis, condensation). This paper proposes a straightforward classification system depending on imaging and sets out the principal symptoms of the main aetiologies of CS lesions which are represented by various diseases such as tumours, inflammations, vascular abnormalities. Complementary to imaging, their diagnosis is based on clinical data i.e. known cancer, signs suggesting inflammation. Its rich iconography allows this article to be used as a reference in current clinical practice.

A wander through the land of the orbit.

This article shows the pathological and physiological images of the orbit, which each radiologist will commonly see in his or her everyday CT scan practice. It explains the images, following the course of the patient's trajectory through imaging as complications develop or in the post-treatment monitoring of some common disorders (orbital trauma, retinal detachment, postoperative appearances).

Magnetic resonance spectroscopy findings in a case of hyperglycaemic hemianopia.

INTRODUCTION: Patients with nonketotic hyperglycaemia may present with neurological manifestations, including hemianopia. Thus far, the pathophysiology of such neurological events remains unknown, although the findings on magnetic resonance imaging (MRI) may help to elucidate the underlying mechanisms. CASE REPORT: This report describes a patient who had an episode of homonymous hemianopia, which coincided with a state of nonketotic hyperglycaemia. Initial MRI showed hypointense areas on T2-weighted and FLAIR sequences, involving the internal portion of the right occipital cortex and adjacent white matter, with mild hyperintensity on diffusion-weighted imaging. Magnetic resonance spectroscopy revealed significant increases in cerebral metabolites. Dramatic clinical and neuroimaging improvements were progressively observed over 3 weeks, following rehydration and normalization of blood glucose levels with insulin therapy. CONCLUSION: In this patient, magnetic resonance spectroscopy was used in combination with other neuroimaging methods and clinical evidence to suggest that hyperosmolality leading to intracellular dehydration in localized brain regions should be considered a potential underlying mechanism responsible for reversible neurological symptoms in nonketotic hyperglycaemia.

[Diagnosis and therapeutic management of an intraorbital organic foreign body]. / Diagnostic et prise en charge des corps étrangers végétaux intra-orbitaires.

INTRODUCTION: Orbital organic foreign bodies are rare and can present different clinical features. The objective of this report is to show the danger of this type of foreign body, present the imaging data, and suggest a diagnostic approach and therapeutic management. We describe three cases of orbital organic foreign bodies with three different clinical presentations. CASE REPORTS: The first case was a 43-year-old male complaining of a chronic cutaneous fistula of the inferior right eyelid lasting 4 months after an orbital trauma with a wooden object. Two surgeries were necessary to extract the foreign bodies. In the second case, a 37-year-old female with post-traumatic ptosis after a bicycle accident several months before, the imaging exams revealed a fracture of the left orbital ceiling and a superior extraconical foreign body that was removed by a neurosurgery approach. The third case, a 69-year-old male with a right orbit abscess following a trauma with a tree branch had a persistent right orbit inflammation lasting 4 months despite two drainage surgeries and an extraction of an orbital organic foreign body. A third surgery was necessary to completely extract the foreign bodies. DISCUSSION/CONCLUSION: Detecting an orbital organic foreign body is sometimes difficult, especially when the clinical history is unclear, the ophthalmologic exam reveals no abnormalities, or if the patient is referred to the hospital several months after the traumatic event. Orbital organic foreign bodies can lead to potentially serious orbital or intracranial complications. Computed tomography and orbital ultrasound sometimes do not yield an evocative pattern: for instance, in computed tomography, the low density of wood can be misdiagnosed as air. On the other hand, these foreign bodies can persist in the orbit after several surgical explorations because they can easily break or migrate. Magnetic resonance imaging is useful when an orbital organic foreign body is suspected, but the analysis is easier when clinical data are suggestive.

The masticator space: from anatomy to pathology.

The masticator space is a deep facial space with a complex anatomical structure. The purpose of the present study was to precisely define the masticator space to eliminate the use of obsolete and confusing terms to describe the area, and to illustrate the common mass syndromes. Primary tumors are uncommon, usually benign and of a vascular or neural origin. Adjacent lesions, mainly pharyngeal with secondary extension into the masticator space, are especially frequent. Metastases are rare, and infectious pathology is often odontogenic. The most frequent lesion of the masticator space is the odontogenic abscess. Multidetector CT and MRI enable precise study of the space, its communications with other deep spaces and the etiology of any mass syndrome. Understanding the anatomy of the masticator space and how it links up with the other deep facial spaces helps the radiologist to recognize the different lesions of this space and to avoid unnecessary surgery, or any other less than optimal management.

Spine metastasis imaging: review of the literature.

Any malignant neoplasm possesses the capacity to metastasize to the musculoskeletal system. Because the spine is the most frequent site of bone metastasis, imaging must be discussed in cases of cancer. Bone marrow is the main interest in imaging the metastatic process by magnetic resonance, while X-rays allow the study of cortical involvement. This article presents our experience, and a review of the literature, in an overview of the different imaging techniques-X-rays and magnetic resonance-with emphasis on the many difficulties that can be encountered in the diagnosis and monitoring of spinal metastases, allowing a management strategy for diagnosis and follow-up.

[Sonography of the eye and orbit with a multipurpose ultrasound unit]. / Echographie de l'oeil et de l'orbite avec un échographe polyvalent.

Our goal is to help echographists and radiologists become familiar with the various possibilities indications, technique and results of ophtalmic ultrasonography. We used a multipurpose ultrasound unit. The frequency of the transducer has to be equal or superior to 7.5 MHz. Color Doppler allowing the study of low flows is useful. The study must be standardized: the first step is to obtain measurements of both eyes. Then the entire globe is systematically evaluated. Finally, the orbital structures and vessels of the eye and orbit are analized. After a review of the anatomy and the normal sonographic features, the main indications are described as well as the main pathologies. Special attention is paid to intravitreal hemorrhage, retinal and choroidal detachments, intraocular tumors and orbital space occupying lesions.

[Vascular tumours and malformation of the orbit]. / Les lésions vasculaires de l'orbite.

Vascular diseases are an important part of orbital pathology. We describe vascular tumours of the orbit and vascular diseases with repercussion on the orbit, from intra or extra orbital origin. The classification of these abnormalities is difficult and several terms are used to describe the same histological entity. The objective of this work is, using the current classification, to illustrate the different imaging aspects of the most frequent vascular diseases of the orbit.

Merkel cell tumor: report of two cases and review of the literature.

The "Merkel cell carcinoma" is a rare tumor usually occuring in the sun-exposed skin. Its poor prognosis is explained by a high rate of metastasis (one third of the patients at the initial presentation) and a high post-operative recurrence rate. Descriptions of the imaging features of this type of tumor are rare. We present two cases of Merkel cell carcinoma localized to the head region. In the first patient, the lesion involved the soft tissues of the scalp with secondary invasion of the skull and meninges. The second patient had a metastasis to the parietal lobe.

The dural tail sign--beyond meningioma.

There have been somewhat conflicting reports published about the significance of linear meningeal thickening and enhancement adjacent to peripherally located cranial mass lesions on contrast-enhanced magnetic resonance (MR) images. Most of the authors consider this so-called "dural tail sign" or "flare sign" almost specific for meningioma. This review illustrates the MR imaging findings of a wide spectrum of disorders that show this dural sign. Causes include other extra-axial lesions and also peripherally located intra-axial lesions such as neuromas, chloromas, metastases, lymphoma, gliomas, pituitary diseases, granulomatous disorders, and also cerebral Erdheim-Chester disease. The dural tail sign is not specific to a particular pathological process. Nevertheless, useful conclusions can be drawn from the morphology of the lesion, its enhancement pattern, and its solitary or multifocal presentation. The final diagnosis must be based on cerebrospinal fluid studies or histological studies after biopsy.

[The sphenoid: tumoral pathology]. / Pathologie tumorale du sphénoïde.

The interest and difficulty of sphenoid tumor imaging relate mainly to its great diversity. Detection may be difficult due to variable tumor size and often misleading clinical data. Because the sphenoid is located at the center of the skull base, tumor extension may be quite variable and difficult to assess, requiring sufficient knowledge of anatomy and imaging features to detect tumor spread, especially retrograde perineural spread, since this has a negative impact on prognosis.

[How to investigate a patient with exophthalmos?]. / Comment explorer une exophtalmie?

Exophthalmos is the main symptom revealing orbital masses. This sign needs to be imaged mainly by MRI and/or CT. As Graves disease is the main etiology of exophthalmos, CT scan should be performed as the initial imaging modality. Indications for US and Doppler are mostly limited to the study of ocular masses, and eventually may help the characterization of extra-ocular lesions. In all cases, imaging is useful to characterize: the precise location of the lesion which can be the intra-conal space (including muscles), the extra-conal space (associated or not to an extra-orbital lesion), or the eyeball; the features of the lesion (density, signal, enhancement.). These findings are used to generate a differential diagnosis. Imaging is also useful to precise the extension of the mass, and in some cases to select the appropriate surgical approach, and for follow-up.

Intravascular malignant lymphomatosis.

Intravascular malignant lymphomatosis is a rare and probably often overlooked disease characterised by massive intravascular proliferation of lymphoid cells, usually with a poor prognosis. CT and MRI appearances are nonspecific; the most suggestive finding being both asymmetrical, bilateral, contrast enhancing high-signal areas on T2 weighting and infarct-like lesions of the cortex and basal ganglia. We report two patients with previously unreported dural and spinal cord involvement.

Radiographic findings in 37 cases of primary CNS lymphoma in immunocompetent patients.

Because of the increasing incidence of primary central nervous system lymphoma (PCNSL), it is essential to recognize this disease in order to start appropriate treatment. We present the characteristic CT and MRI features of this tumour. The findings of 32 CT and 31 MR of 37 immunocompetent patients with biopsy-proved PCNSL are reviewed. The main features are presented and analysed, and are discussed in comparison with proven literature data. Primary central nervous system lymphoma presents as supratentorial solitary lesions in approximately 80% of the patients and multiple lesions in 20%. In contrast to classical data, the lesions are located in deep structures only in one-third of the cases, and involve posterior fossa in 10% of cases. Most of the lesions are hyperdense or isodense (92%) on CT, hypointense or isointense on T1-weighted images, and only about 40% are hyperintense on T2-weighted images. Nearly all the lesions enhance, except after corticosteroid administration. They produce mild oedema and mass effect. Meningeal or ventricular enhancement are rare but suggestive. Calcification, haemorrhage or necrosis are scarce. Although PCNSL in immunocompetent patients have a variable CT and MR appearance, the imaging data often suggest the diagnosis.