J. Ito

Radiologic anatomy of the brain

1. Cerebral Hemisphere.- 1. Fissures and Sulci (G. S.).- I. Anatomic Study of the Fissures and Sulci of the External Surface of the Cerebral Hemisphere.- 1. Principal or Interlobar Fissures.- 2. Sulci of the External Surface.- a) Sulci of the Frontal Lobe.- b) Sulci of the Parietal Lobe.- c) Sulci of the Occipital Lobe.- d) Sulci of the Temporal Lobe.- II. Anatomic Study of the Fissures and Sulci of the Internal Surface of the Cerebral Hemisphere.- 1. Fissures of the Internal Surface.- 2. Sulci of the Internal Surface.- III. Anatomic Study of the Fissures and Sulci of the Inferior Surface of the Cerebral Hemisphere.- 1. Fissure of the Inferior Surface-Sylvian Fissure.- 2. Sulci of the Inferior Surface.- a) Sulci of the Orbital Surface of the Frontal Lobe.- b) Sulci of the Inferior Surface of the Temporal and Occipital Lobes.- IV. Radiologic Study of Fissures and Sulci.- 2. Lateral Ventricles (G. S.).- I. Anatomic Study of the Lateral Ventricles.- 1. Frontal Horn of the Lateral Ventricle.- 2. Body of the Lateral Ventricle.- 3. Atrium of the Lateral Ventricle.- 4. Occipital Horn of the Lateral Ventricle.- 5. Temporal Horn of the Lateral Ventricle.- II. Radiologic Study of the Lateral Ventricles.- 1. Frontal Horn of the Lateral Ventricle.- 2. Body of the Lateral Ventricle.- 3. Atrium of the Lateral Ventricle.- 4. Occipital Horn of the Lateral Ventricle.- 5. Temporal Horn of the Lateral Ventricle.- 3. Cortical Arteries (G. S.).- A. Anterior Cerebral Artery.- I. Anatomic Study of the Anterior Cerebral Artery.- Branches of the Anterior Cerebral Artery.- a) Branch to the Orbital Surface of the Frontal Lobe.- b) Branches to the Internal Surface of the Frontal Lobe.- c) Branch to the Paracentral Lobule.- d) Branches to the Internal Aspect of the Parietal Lobe.- e) Branches to the Corpus Callosum.- II. Radiologic Study of the Anterior Cerebral Artery.- B. Middle Cerebral Artery.- I. Anatomic Study of the Middle Cerebral Artery.- 1. Patterns of Division of the Middle Cerebral Artery within the Sylvian Fissure.- 2. Frontal Branches of the Middle Cerebral Artery.- 3. Parietal Branches of the Middle Cerebral Artery.- 4. Temporal and Temporo-Occipital Branches of the Middle Cerebral Artery.- 5. Insular Branches.- II. Radiologic Study of the Middle Cerebral Artery.- C. Anterior Choroidal Artery.- I. Anatomic Study of the Anterior Choroidal Artery.- II. Radiologic Study of the Anterior Choroidal Artery.- D. Posterior Cerebral Artery.- I. Anatomic Study of the Posterior Cerebral Artery.- II. Radiologic Study of the Posterior Cerebral Artery.- 4. Basal Cerebral Vein (Y. P. H.).- A. Normal Anatomy.- I. First Segment of the Basal Cerebral Vein and Its Tributaries.- 1. Deep Middle Cerebral Vein.- 2. Inferior Striate Veins.- 3. Olfactory Vein.- 4. Fronto-Orbital Veins.- 5. Anterior Cerebral and Pericallosal Veins.- 6. Veinlets from the Optic Chiasm, Optic Tract, and Adjacent Structures.- II. Second Segment of the Basal Cerebral Vein and Its Tributaries>.- 1. Peduncular Vein.- 2. Inferior Ventricular Vein.- III. Third Segment of the Basal Cerebral Vein and Its Tributaries.- 1. Lateral Mesencephalic Vein.- 2. Lateral Atrial Vein.- 3. Medial Temporal and Occipitotemporal Cortical Veins.- 4. Posterior Longitudinal Hippocampal Vein.- 5. Posterior Thalamic Veins.- B. Anatomic Variations.- 2. Mesencephalic Region, Diencephalic Region, and Basal Ganglia.- 1. Third Ventricle and Suprasellar Cisterns (G. S.).- I. Anatomic Study of the Third Ventricle and Suprasellar Cisterns.- 1. Third Ventricle.- 2. Suprasellar Cisterns.- II. Radiologic Study of the Third Ventricle and Suprasellar Cisterns.- 2. Aqueduct of Sylvius (G. S.).- I. Anatomic Study of the Aqueduct of Sylvius.- II. Radiologic Study of the Aqueduct of Sylvius.- 3. Arteries of the Basal Ganglia and the Posterior Choroidal Arteries (G. S.).- I. Anatomic Study of the Perforating Arteries of the Basal Ganglia and of the Posterior Choroidal Arteries.- 1. Perforating Branches of the Carotid System.- a) Perforating Branches of the Anterior Cerebral Artery.- b) Perforating Branches of the Middle Cerebral Artery.- c) Perforating Branches of the Anterior Choroidal Artery.- 2. Perforating Branches of the Vertebrobasilar System.- a) Arteries to the Inferior Surface of the Thalamus.- b) Arteries to the Posterior Surface of the Thalamus.- c) Arteries to the Superior Surface of the Thalamus.- II. Radiologic Study of the Perforating Arteries of the Basal Ganglia and of the Posterior Choroidal Arteries.- 4. Deep Cerebral Veins (Y. P. H.).- A. Internal Cerebral and Great Cerebral Veins.- B. Subependymal Veins of the Lateral Ventricle.- I. Medial Group of theSubependymal Veins.- 1. Septal Vein.- 2. Posterior Septal Vein.- 3. Medial Atrial Vein.- 4. Transverse Hippocampal Subependymal Veins.- II. Lateral Group of the Subependymal Veins.- 1. Thalamostriate Vein.- 2. Direct Lateral Vein.- 3. Inferior Ventricular Vein.- C. Choroidal Veins of the Lateral Ventricle.- D. Veins of the White Matter of the Cerebral Hemisphere-Medullary Veins.- E. Veins of the Grey Matter of the Cerebral Hemisphere.- 3. Posterior Fossa.- 1. Fourth Ventricle and Cisterns of the Posterior Fossa (G. S.).- I. Anatomic Study of the Fourth Ventricle.- 1. Floor of the Fourth Ventricle.- 2. Roof of the Fourth Ventricle t2.- II. Anatomic Study of the Posterior Fossa Cisterns.- 1. Cisterns Anterior to the Brainstem.- a) Medullary Cistern.- b) Pontine Cistern.- c) Cerebellopontine Angle Cistern.- 2. Cistern Posterior to the Medulla and Below the Inferior Vermis-Cisterna Magna.- 3. Cisterns Posterior to the Tectum and Superior to the Cerebellum.- 4. Cisterns Around the Cerebral Peduncles.- III. Radiologic Study of Posterior Fossa, Fourth Ventricle and Cisterns of the Posterior Fossa.- 2. Arteries of the Vertebrobasilar System (G. S.).- I. Anatomic Study of the Arteries of the Vertebrobasilar System.- 1. Intracranial Segment of the Vertebral Artery.- 2. Basilar Trunk.- 3. Arteries of the Brainstem.- a) Arteries of the Medulla.- b) Arteries of the Pons.- c) Arteries of the Cerebral Peduncles.- 4. Arteries of the Cerebellum.- a) Superior Cerebellar Artery-SCA.- b) Anterior Inferior Cerebellar Artery-AICA.- c) Posterior Inferior Cerebellar Artery-PICA.- II. Radiologic Study of the Arteries of the Vertebrobasilar System.- 1. Basilar Trunk and Its Branches.- 2. Anterior. Inferior Cerebellar Artery-AICA.- 3. Superior Cerebellar Artery-SCA.- 3. Veins of the Posterior Fossa (Y. P. H.).- I. Superior or Galenic Draining Group.- 1. Mesencephalic Tributaries.- 2. Cerebellar Tributaries.- II. Anterior or Petrosal Draining Group.- 1. Tributaries Related to the Anterior Aspect of the Brain Stem.- 2. Tributaries Related to the Wing of the Precentral Cerebellar Fissure.- 3. Tributaries Related to the Posterolateral Fissure.- 4. Tributaries Related to the Cerebellomedullary Fissure.- 5. Tributaries Related to the Cerebellar Hemisphere.- III. Posterior or Tentorial Draining Group.- IV. Intercommunications Among the Superior, Anterior and Posterior Draining Groups and Between the Supra- and Infratentorial Veins.- V. Circulation Times of Veins of the Posterior Fossa.- References.

Dural arteriovenous malformations of the base of the anterior cranial fossa

SummaryTwo cases of dural arteriovenous malformation at the base of the anterior fossa are reported. The angiographic appearance in both cases is quite uniform and resembles the findings in 12 cases previously reported. Feeders are anterior and/or posterior ethmoidal arteries and the external carotid system also contributes. A drainage vein always shows aneurysmal dilatation of its proximal portion. CT findings are also mentioned and radiological literature reviewed.

Fenestration of the Anterior Cerebral Artery

SummaryThree cases of angiographically demonstrated fenestration of the anterior cerebral artery are reported. Fenestration occurred at the medial half of the horizontal segment of the anterior cerebral artery in all cases. Its embryology and clincial significance are briefly discussed, and the anatomical and radiological literature on fenestration of the anterior cerebral artery is reviewed.

Anomalous origin of the anterior inferior cerebellar arteries from the internal carotid artery

SummaryTwo cases of the anterior inferior cerebellar arteries originating from the cavernous and precavernous segments of the internal carotid artery are reported. In one case the course of the anomalous artery was confirmed by autopsy. This anomalous artery is considered to be a variant of persistent primitive trigeminal artery. The clinical significance is discussed briefly.

Veins of the Posterior Fossa

During the development of the embryo, the first vein to appear in the posterior fossa is, according to PADGET (1956), the primitive ventral metencephalic vein since, at this stage, the cerebellar hemisphere is merely represented by a cerebellar plate. This ventral metencephalic vein, homologous to the trigeminal vein of lower vertebrates, will eventually become the petrosal vein. The proximal end of the ventral metencephalic vein becomes incorporated into the petrous crest to form the superior petrosal sinus. The primitive ventral myelencephalic vein, also called the vagal vein (PADGET, 1956), anastomoses superiorly with the ventral metencephalic vein and drains the medulla oblongata. The inferior petrosal sinus is derived from the proximal end of the ventral myelencephalic vein.

Computed tomography in moyamoya disease.

Eighteen patients with moyamoya disease were examined by computed tomography (CT). At the first examination, CT findings were normal in one patient and abnormal in 17 patients. Significant abnormalities on precontrast CT were characterized by low density lesions in 14, ventricular dilatation in 9, and cerebral atrophy in 11 patients. Postcontrast CT showed the presence of contrast enhanced lesions in three patients. Follow-up examinations were performed in 13 patients, and the following changes on CT were found in 10 of them: increase or development of low density lesions in 10, ventricular dilatation in 4, cerebral atrophy in 5, appearance of a contrast enhanced lesion in 1, and disappearance of the enhanced lesion in 3. The patient with normal findings at the first examination showed a low density lesion on the second examination. The abnormal vascular networks in the region of the basal ganglia were visualized successfully in six examinations of five patients by higher concentration of contrast medium in blood than usual. Abnormal CT findings consisted of those seen in multiple cerebral infarctions and the visualization of the abnormal vascular networks. Computed tomographic findings on these patients showed evolution as seen in clinical and angiographic findings.

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.

Application of computed tomography for diagnosis of alveolar bony defects

This study was performed to evaluate the usefulness of computed tomography (CT) in analyzing the three-dimensional structure of alveolar bony defects. The result showed that differences between CT film and actual readings from the cusp ridge to the bone crest were negligible, and the reading on CT film was underestimated approximately 1 mm at the distance from the cusp ridge to the bottom of the bony defect. By reading a series of CT films, one can easily evaluate the type of bony defects. Therefore, application of CT maybe useful for analyzing three-dimensional structure and diagnosis of the alveolar bony defects.

Fat in the dural sinus-CT and anatomical correlations

SymmaryTwo 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.

Fat in the dural sinus

SummaryFat density in the dural sinus on computed tomography (CT) is described in eight cases. Of the eight cases, five had fat deposit in the torcular Herophili, and three in the superior sagittal sinus. This finding was incidentally found by CT and there was no common underlying disease in these cases. It is suggested that this finding represents normal adipose tissue in the dural sinus.