MRI venous architecture of insula.

PURPOSE: The purpose of this paper is to describe the venous anatomy of the insula using conventional MR brain imaging and confocal reconstructions in cases with glioma induced venous dilatation (venous gliography). METHODS: Routine clinical MRI brain scans that included thin cut (1.5-2 mm) post contrast T1 weighted imaging were retrospectively reviewed to assess the insular venous anatomy in 19 cases (11 males and 8 females) with insular gliomas. Reconstruction techniques (Anatom-e and Osirix) were used to improve understanding of the venous anatomy. RESULTS: We identified the following insular and peri-insular veins on MRI: the superficial middle cerebral vein (SMCV), peri-insular sulcus vein, vein of the anterior limiting sulcus, the precentral, central, and posterior sulcus veins of the insula, the communicating veins and deep MCV. CONCLUSIONS: We concluded that venous anatomy of insula is complicated and is often overlooked by radiologists on MR brain imaging. Use of confocal imaging in different planes helped us to identify the superficial and deep middle cerebral veins and their relationship to the insula. The understanding of the insular venous architecture is also useful to distinguish these vessels from insular arteries. This knowledge may be helpful for presurgical planning prior to insular glioma resection.

MRI venous architecture of the thalamus.

PURPOSE: Our purpose is to describe the thalamic veins using a novel approach named venous gliography in cases with primary or secondary gliomas of the thalamus. Venous gliography is defined by authors as a method to visualize veins on MRI Brain T1-weighted post contrast scans containing gliomas which have induced regional venous congestion. METHODS: Routine clinical MR Imaging studies were reviewed to assess the presence of thalamic veins in 29 glioma cases. In addition, confocal reconstruction techniques (Anatom-e and Osirix) were used in cases that had thin sections (1.0-1.5mm) post contrast T1 weighted sequences. Multiplanar MIP and confocal volume rendered images were generated to evaluate the thalamic veins in those cases. RESULTS: Using venous gliography and confocal reconstruction techniques, two patterns in the venous architecture of the thalamus were documented. First, the branching pattern created by the tributaries of the internal cerebral vein, namely the superior thalamic vein and the anterior thalamic vein, which together formed the superior group of thalamic veins. Second, the pattern created by the un-branched vertically oriented veins, namely the inferior thalamic veins and the posterior thalamic veins, which joined the basal vein of Rosenthal and constituted the inferior group of thalamic veins. CONCLUSIONS: Venous gliography combined with the use of confocal reconstruction techniques provided a novel approach to display the thalamic veins that are usually not seen. The understanding of the venous architecture is mandated by the recent research where veins have taken on an important role in the perivenular spread of gliomas.

Glial tumors in brodmann area 6: spread pattern and relationships to motor areas.

The posterior frontal lobe of the brain houses Brodmann area 4, which is the primary motor cortex, and Brodmann area 6, which consists of the supplementary motor area on the medial portion of the hemisphere and the premotor cortex on the lateral portion. In this area, safe resection is dependent on accurate localization of the motor cortex and the central sulcus, which can usually be achieved by using thin-section imaging and confirmed by using other techniques. The most reliable anatomic landmarks are the "hand knob" area and the marginal ramus of the cingulate sulcus. Postoperatively, motor deficits can occur not only because of injury to primary motor cortex but also because of injury to the supplementary motor area. Unlike motor cortex injury, the supplementary motor area syndrome is transient, if it occurs at all. On the lateral hemisphere, motor and language deficits can also occur because of premotor cortex injury, but a dense motor deficit would indicate subcortical injury to the corticospinal tract. The close relationship of the subcortical motor fibers and premotor cortex is illustrated. In contrast to the more constant landmarks of the central sulcus and marginal ramus, which aid in preoperative localization, the variable interruptions in the precentral and cingulate sulci of the posterior frontal lobe seem to provide "cortical bridges" for spread of infiltrating gliomas.