Fat in the dural sinus

Imaging of intracranial fat: from normal findings to pathology

The presence of intracranial adipose tissue is often overlooked, although it may be detected in different physiological (dural sinuses or falx deposition of fat) and pathological (lipoma, dermoid cyst, subarachnoid fat dissemination) conditions. In this review, we illustrate various scenarios in which radiologists and neuroradiologists may encounter intracranial fat, providing a list of differential diagnosis.

Hypodense cerebral venous sinus thrombosis on unenhanced CT: A potential pitfall. Report of a case and review of the literature

Cerebral venous sinus thrombosis is an uncommon disorder that requires prompt diagnosis and treatment to prevent serious complications. Due to the broad spectrum of clinical presentations, patients typically undergo noncontrast CT as the first imaging study. The classical description of cerebal venous sinus thrombosis on noncontrast CT is a hyperdense thrombus within the dural venous sinus. We report an unusual case of a hypodense cerebral venous sinus thrombosis on unenhanced CT imaging. It is important for radiologists to be aware of this atypical appearance that to our knowledge has not been previously published.

Cranial venous outflow obstruction and pseudotumor Cerebri syndrome

The pathophysiology of PTS including idiopathic intracranial hypertension or 'BIH', remains controversial. The older literature frequently referred to pathology in the cerebral venous drainage but more modern imaging techniques (CT and early MR) failed to reveal gross venous pathology. The role of impaired cranial venous outflow has recently been re-examined in the light of new methods of investigation (advanced MR venography and direct microcatheter venography with manometry) and of treatment (venous sinus stenting). Venous sinus obstruction in PTS is a more common factor in the pathogenesis of the condition than previously recognised. Venous obstruction may be primary, that is, it is the underlying aetiological factor in PTS. Venous sinus obstruction may also be secondary to raised CSF pressure which may exacerbate problems with intracranial compliance and raised CSF pressure. Early experience with venous stenting suggests that it may be a helpful treatment for patients with PTS but more experience and longer follow-up is required to define the subgroups of patients for whom it is most appropriate.

Sagittal sinus occlusion by intraluminal dural cysts. Report of two cases

Lesions involving the sagittal sinus typically present as masses compressing the sinus externally. The authors describe two cases of lesions entirely within the lumen of the sagittal sinus. In one of the cases, syncope was the presenting symptom and surgical resection of the cyst was performed. An entirely intraluminal cyst, consistent with a dural cyst, was resected, followed by reconstruction of the sinus and resolution of symptoms. Entirely intraluminal lesions of the sagittal sinus have rarely been reported as incidental findings. This represents the first report of symptomatic occlusion of a venous sinus by an intraluminal cyst.

CT of the pacchionian body

The CT appearances of the pacchionian body, confirmed at autopsy, are reported. The pacchionian body appears as a low density mass in the dural venous sinus, of almost the same density as the subarachnoid space.

Fat in the dural sinus--CT and anatomical correlations

Two cases of fat in midline dural sinuses, detected by high-resolution CT, were studied anatomically. The fat nodules were not located in the sinus lumen, but in the sinus wall. They were composed of normal adipose tissue without fibrous encapsulation. Our findings have proved that the fat deposit as demonstrated by CT within these dural sinuses represents normal adipose tissue in the sinus wall and does not necessarily mean the presence of a fatty tumor.