Satoshi Tsutsumi1, Hideo Ono2, Hisato Ishii3. 1. Department of Neurological Surgery, Juntendo University Urayasu Hospital, 2-1-1 Tomioka, Urayasu, Chiba, 279-0021, Japan. shotaro@juntendo-urayasu.jp. 2. Division of Radiological Technology, Medical Satellite Yaesu Clinic, Tokyo, Japan. 3. Department of Neurological Surgery, Juntendo University Urayasu Hospital, 2-1-1 Tomioka, Urayasu, Chiba, 279-0021, Japan.
Abstract
PURPOSE: To date, no study has explored the inferior sagittal sinus (ISS) using neuroimaging modalities. This investigation aimed to characterize it using magnetic resonance imaging (MRI). METHODS: A total of 77 patients with intact cerebral hemispheres and covering meninges underwent thin-sliced, contrast-enhanced MRI. RESULTS: The ISS was well delineated as a linear structure with a constant diameter in 97% of the patients. The maximum intensity projection (MIP) images well delineated the three-dimensional architecture of the ISS and relevant veins. The identified ISSs could be classified into three different types, with the underdeveloped type being the most frequent at 47%. In addition, the ISSs showed considerable variability both in the original site and course along the lower margin of the falx cerebri. Furthermore, in 22% of the cases, fenestrations were identified in the falx cerebri adjacent to or near the ISS. More than 70% of them were located in the middle third of the falx, followed by the anterior and middle thirds of the falx. CONCLUSIONS: The ISS is a constant venous structure characterized by morphological variability and may function as an adjunctive or assistive venous drainage route. Thin-sliced, post-contrast-enhanced sagittal MRI combined with MIP imaging is useful for exploring the ISS.
PURPOSE: To date, no study has explored the inferior sagittal sinus (ISS) using neuroimaging modalities. This investigation aimed to characterize it using magnetic resonance imaging (MRI). METHODS: A total of 77 patients with intact cerebral hemispheres and covering meninges underwent thin-sliced, contrast-enhanced MRI. RESULTS: The ISS was well delineated as a linear structure with a constant diameter in 97% of the patients. The maximum intensity projection (MIP) images well delineated the three-dimensional architecture of the ISS and relevant veins. The identified ISSs could be classified into three different types, with the underdeveloped type being the most frequent at 47%. In addition, the ISSs showed considerable variability both in the original site and course along the lower margin of the falx cerebri. Furthermore, in 22% of the cases, fenestrations were identified in the falx cerebri adjacent to or near the ISS. More than 70% of them were located in the middle third of the falx, followed by the anterior and middle thirds of the falx. CONCLUSIONS: The ISS is a constant venous structure characterized by morphological variability and may function as an adjunctive or assistive venous drainage route. Thin-sliced, post-contrast-enhanced sagittal MRI combined with MIP imaging is useful for exploring the ISS.