Intramedullary Spinal Lesions Involving the Conus Medullaris: MR Imaging Features for Differential Diagnosis

PURPOSE: Intramedullary spinal lesions in the conus medullaris (CM), including tumors and vascular lesion, are rarely reported. We reported various MR features of intramedullary spinal cord lesions involving the CM including ependymoma, hemangioblastomas, dermoid cyst, ventriculus terminalis and spinal AVF and tried to discuss them for differential diagnosis. MATERIALS AND METHODS: Six patients (male: female = 4:2, mean age = 44.3 year old) were enrolled from the clinical database of our institute from 2004 to 2010 and their radiological images and clinical symptoms were reviewed retrospectively. All patients had taken initial and postoperative MRI with contrast enhancement using gadopentate dimeglumine (Gd-DTPA). These images were analyzed by tumor size, location, signal intensity relative to the spinal cord, vascular flow voids, syrinx or cyst, edema and enhancement pattern. RESULTS: Contrast enhancement was seen in all intramedullary masses. An eccentric enhancing nodule was noted in two hemangioblastomas and unusual peripheral rim enhancement with septation was seen in ventriculus terminalis. Patchy enhancement of the CM was observed in spinal arteriovenous fistula (AVF). Extensive cord edema adjacent to the intramedullary lesions was seen in four cases and syrinx was noted in three cases. Vascular signal voids were found in two hemangioblastomas and one spinal AVF. CONCLUSION: In evaluation of intramedullary spinal lesions in the CM, it is necessary to consider these unusual MR findings and discriminate various pathologies with prudence and caution.

Ventriculus Terminalis in Adults: Unusual Magnetic Resonance Imaging Features and Review of the Literature

OBJECTIVE: The ventriculus terminalis (VT) in adults is a rare pathology. We report various MR imaging features of the adult VT. MATERIALS AND METHODS: Ten patients were included in this retrospective review.. All patients had undergone magnetic resonance (MR imaging with a surface coil that used two different 1.5T MR systems. All patients had undergone initial and follow-up MR imaging with contrast enhancement using gadopentate dimeglumine. Three patients underwent additional MR imaging using the echocardiogram-gated spatial modulation of magnetization (SPAMM) technique. If a shift in tagging band during the systolic phase was less than half of the band space, it was defined as a "non-pulsatile fluid". Two neuroradiologists independently reviewed these images, while clinical symptoms and outcomes were statistically analyzed between the treated and non-treated group. RESULTS: All cases presented an intramedullary cystic lesion in the conus medullaris and showed the same signal intensity as CSF. Three VTs had intracystic septation and cord edema, which were pathologically confirmed after surgery; two of these were associated with kyphotic deformity and spinal arteriovenous malformation. SPAMM-MRI of 3 patients demonstrated non-pulsatile fluid motion within the VT. In the treated group, clinical symptoms improved better than the non-treated group. CONCLUSION: The adult VT shows some unusual imaging features, including septation, cord edema, and coexistence of a spinal AVM, as well as the typical findings. Surgical maneuvers may be considered as a treatment option in adult VT with progressive neurological symptoms.

Developmental Changes of Glial Fibrillary Acidic Protein (GFAP) and Proliferating Cell Nuclear Antigen (PCNA) Immunoreactivity of the Ependyma lining the Central Canal and Ventriculus Terminalis in the Human Fetus / 대한해부학회지

The distinguishing morphological features of the ependyma lining ventriculus terminalis in human fetus have suggested that its differentiation would be somewhat delayed or arrested as compared with the ependyma lining central canal. To demonstrate this hypothesis, GFAP was used as a marker to compare the developmental state of the ependyma lining ventriculus terminalis and central canal along fetal age (18 -to 24 -week -old fetuses were investigat-ed). PCNA was also used as a marker to identify whether proliferation potentiality of the ependyma lining ventriculus terminalis lasted longer than that of the ependyma lining central canal as a result of differentiation delay. GFAP -positive ependymal cells were restricted to dorsal plate at central canal but at ventriculus terminalis, many positive cells were identified in all regions compared with the ependyma lining central canal. The number of PCNA -positive ependymal cells lining central canal decreased sharply about the time of 20th week, but at ventriculus terminalis, many ependymal cells continued to express PCNA after 20th week. As a result, we could conclude that differentiation of the ependyma lining ventriculus terminalis is delayed as compared with the ependyma lining central canal. In accordance with its developmental delay, it lasts longer proliferation potentiality than the ependyma lining central canal.

Morphological Study of the Ventriculus Terminalis in the Human Fetal Spinal Cord / 대한해부학회지

The ventriculus terminalis, also known as the 'fifth ventricle', is a dilated cavity in the conus medullaris. It is formed by degenerative process in the course of neural tube development, but the definite function is unclear. And the reports, which have studied the morphological variation according to fetal age, are insufficient. So, in this report, we observed the morphological variation of the ventriculus terminalis and measured the areal ratio of the ventriculus terminalis to the parenchyma of conus medullaris by fetal age. We also studied the fine structure of the conus medullaris and ependyma by electron microscope. The ventriculus terminalis began at the level at which the ependymal cells proliferated and the central canal moved to the dorsal region. Periependymal islet was observed at this level. At the lower level, it immediately extended both lateral sides and finally switched over to the filum terminale. The area ratio of the ventriculus terminalis to the parenchyma of the conus medullaris increased from above downward. Especially, It increased steeply between the Leaf-shaped region and the transitional zone, where the ventriculus terminalis began. But the increasing pattern was too irregular to generalize its pattern by fetal age. The ependyma lining the ventriculus terminalis was composed of pseudostratified ciliated columnar epithelium layer about 5~7 cells thick. It had conspicuous intercellular junctional complexes close to the lumen into which microvilli and cilia projected. At the junction where the ependyma meets the parenchyma of the conus medullaris, we could observe many myelin-like structures made by basolateral membrane of the ependymal cell. In the conus medullaris, we could observe many obscure cell types because they were in the course of differentiation. On the other hand, we could also observe the fully differentiated nerve cells, astrocytes and oligodendrocytes which seemed to play its own role. A lot of developing myelin sheaths were observed and the majority was the degenerative one. Some ependymal cells showed the apoptotic characteristics and many cell debris were observed in the lumen. As a result, the ventriculus terminalis was formed by the combination of cell differentiation and degeneration, and its development was independent of the spinal cord.