The sagittal stratum (SS) was originally defined and explored in white matter fiber dissection studies. The term represents the structures located close to and lateral to the trigon of the lateral ventricle and consisting of several layers of white matter bundles running in an anteroposterior (sagittal) direction. The SS includes the optic radiation, posterior ramus of the thalamic peduncle, anterior commissure, inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, and middle longitudinal fasciculus. SS is assumed to play an essential role in various cognitive functions. It includes those, as mentioned above, major associations and commissural fiber bundles connecting broad areas of the cerebral cortex, such as visual, semantic, and language functions. In this article, we explore the anatomical characteristics of the SS through applying modern imaging technology, the generalizing q-sampling imaging tractography.
Precise assessment of the angioarchitecture of cerebrovascular diseases is important for accurate diagnosis and planning surgical, endovascular, or conservative management to minimize the risk of treatment complications. Recent advancements in angiography techniques have enabled the acquisition of high-quality vascular images, even for small vessels, using rotational angiography and cone-beam CT. It is also possible to precisely assess the relationship between vascular pathology and the surrounding normal vessels or other anatomical structures by developing fusion images with other angiographic images or MRI. For example, before aneurysm treatment, we can preoperatively assess the origin and course of the perforators associated with an aneurysm. For spinal shunt diseases, the shunt point can be precisely identified in relation to the surrounding spinal cord, nerve root, dura, and bony and soft tissue structures. This information is important for accurate diagnosis, understanding of the disease, and treatment planning. Vascular imaging with high-resolution angiography is progressively improving and becoming indispensable for the diagnosis and treatment of cerebrovascular diseases.
The choice of surgical approach is among the most important considerations in the surgical study of brainstem cavernous malformations. Specific considerations include whether the approach is the one with the lowest likelihood of worsening neurological symptoms, whether a field of view can be secured so that the lesion can be completely removed, and whether the complicated developmental venous anomaly can be preserved. Furthermore, it is necessary to consider a three-dimensional surgical approach in which the lesion on the most superficial part of the brainstem is the most accessible point. Accordingly, knowledge of normal anatomy and safe entry zones (SEZs) is critical. No-kan is a free app developed by the Department of Neurosurgery at the University of Tokyo that allows users to study the anatomy of the brainstem and SEZs. The app shows numerous cranial nerves, nuclei, and white matter fibers present in the brainstem as three-dimensional computer graphics. The points of surgical approach to 16 SEZs reported in 21 studies are also described. With the aim of promoting understanding of the surgical anatomy of the brainstem in three dimensions, this paper outlines the anatomy of the brainstem focusing on SEZs, with reference to 3D computer graphics in the No-kan app.
The image quality of surgical endoscopes has greatly improved, and there are more opportunities to perform endoscopic endonasal skull base surgery using full high-definition endoscopes or 4K endoscopes. In this article, the anatomy around the sella turcica is presented with cadaver photographs, considering its relationships with intracranial structures, together with the surgical cases. Both the medial optico-carotid and lateral optico-carotid recesses are key structures that promote understanding of endonasal and intracranial anatomy. The vidian canal is also a useful surgical landmark around the internal carotid artery, near the foramen lacerum. Acquiring knowledge of the skull base anatomy both from the cranial and the endonasal side through cadaver training is integral to the pursuit of safer and more effective surgery.
We have outlined the modern cadaver surgical training to facilitate safe complex and advanced skull base surgeries. The normal formalin-fixed cadaver head was useful for learning detailed skull base anatomy and histological research by removing the brain. Our fixation method, with the addition of phenol, ethanol, and methanol, was suitable for surgical simulation. To utilize the dissection performed by doctors for the development of surgical skills, it is essential to create an organization within the university.
The potential adverse effects of ionizing radiation exposure during imaging studies are particularly relevant to the pediatric population. To reduce radiation exposure, quick-brain (or rapid sequence) MR imaging has been used to evaluate cerebral ventricle size in pediatric patients with hydrocephalus in Western countries. The objective of this study was to evaluate the quality of images obtained using non-sedative quick-brain MR imaging and consider its merits and limitations.
We retrospectively analyzed a series of quick-brain MRI studies performed without sedation for pediatric patients with hydrocephalus.
A total of 41 quick-brain MRI examinations were performed without sedation for pediatric patients with hydrocephalus with a median age of 9 months at the time of examination. The duration of each study was less than 30s. The catheter visualization was good, and the image quality was excellent enough for evaluating the cerebral ventricle size.
Non-sedative quick-brain MR imaging is reliable for evaluating the ventricle size and ventricular catheter in pediatric patients with hydrocephalus.
To the best of our knowledge, this is the first report of a metastatic brain tumor extended from a liposarcoma with cerebral hemorrhage. An 81-year-old man underwent extensive tumor resection and reconstructive surgery for a left leg tumor, and the pathological diagnosis was dedifferentiated liposarcoma. He was admitted to our hospital for sudden headache, vomiting, and left hemiparesis. CT and MRI revealed a subcortical hemorrhage in the right frontoparietal lobe and a neoplastic lesion was observed in the hematoma. There was also a 1-cm neoplastic lesion that was uniformly gadolinium-enhanced in the left cerebellar hemisphere. FDG uptake was observed in the tumor of the right frontal lobe and left cerebellum hemisphere, except in the area of intratumoral hemorrhage. The patient underwent surgery for intracerebral hemorrhage and a brain tumor in the right frontoparietal lobe. The tumor was partially exposed on the surface of the brain and was completely removed with dissection at the border of the normal brain. Pathological findings showed dense growth of spindle-shaped multipolar tumor cells. Necrosis and hemorrhage were also observed, with vacuolar changes in some cytoplasms. The tumor was composed of large and small irregular atypical adipocytes, fibroblasts, and other cells with irregularly nucleated adipoblasts. Immunostaining was positive for MDM2 and CDK4. Therefore, we diagnosed the patient with brain metastases of dedifferentiated liposarcoma. Soft tissue sarcoma, a malignant tumor, requires multidisciplinary treatment, and novel drugs are being developed. The establishment of effective therapies may prolong survival and increase the number of metastatic brain tumors ; therefore, careful follow-up is necessary.