E2297. Spot the Clot: Medullary Venous Thrombosis and Beyond
  1. Elizabeth England; Monroe Carell Jr. Children's Hospital; Vanderbilt University and Medical Center
  2. Asha Sarma; Monroe Carell Jr. Children's Hospital; Vanderbilt University and Medical Center
  3. Sumit Pruthi; Monroe Carell Jr. Children's Hospital; Vanderbilt University and Medical Center
  4. Arjun Patel; Monroe Carell Jr. Children's Hospital; Vanderbilt University and Medical Center
Detailed cerebral venous anatomy is complex. Additionally, the pediatric cerebral venous pathologies are a diverse group of entities, many of which are unique to young infants. Some of these entities are related to perinatal stroke, white matter injury, and hemorrhage. This educational exhibit will prepare the radiologist to review less-discussed topics in cerebral venous anatomy such as the deep and superficial medullary veins, recognize and understand a broad variety of superficial and deep venous pathologies in children, and appreciate lesser-known venous pathologies involving the cortical veins and deep veins.

Educational Goals / Teaching Points
The educational goals of this exhibit are to clearly outline relevant cerebral venous anatomy, emphasize the radiographic findings of multiple superficial and deep medullary venous pathological entities, illustrate MRI techniques that are useful for imaging the cerebral veins, and describe lesser-known imaging manifestations of venous thrombosis including subpial hemorrhage, subependymal hemorrhage, and more. A comprehensive list of conditions that will be described includes deep medullary vein thrombosis and engorgement, cerebral venous metameric syndrome, sturge Weber (a spectrum of venous abnormalities), superficial venous thrombosis, subpial hemorrhage, subependymal hemorrhage, grade IV germinal matrix hemorrhage, and Rocky Mountain Spotted Fever and Human Parechovirus Meningoencephalitis.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Deep medullary vein engorgement can result in edema and hemorrhage in a territory of abnormal venous flow. When there is stasis or disruption in the immature cerebral veins, the deep medullary and subependymal veins become engorged and demonstrate abnormal flow mechanics. The sequelae are best demonstrated on various MRI pulse sequences including T1- and T2WI, T2* imaging, MR venography, and postcontrast imaging in selected cases. Subpial hemorrhage is a unique entity seen in neonates in a variety of clinical settings, including clotting disorders, hypoxia, trauma, and alterations in intracranial pressure. When injury occurs, the venous-capillary hemorrhage lifts the loosely adherent pia matter, allowing for accumulation of blood products. This causes disruption of the pia-glia limitans interface, resulting in abnormal organization of cortical neurons and vessels. Overall, this can cause atypical cortical developmental and long term neurological effects.

Familiarity with the cortical venous anatomy is critical for accurate diagnosis of numerous pathologies on neonatal brain MRI. Diagnoses including deep medullary venous congestion and thrombosis are common; however, less well-described entities such as subependymal hemorrhage, subpial hemorrhage, and cerebral venous metameric syndrome can be more challenging to characterize. Management of these entities varies; thus, a thorough understanding of these entities is critical to appropriate assessment and management of the pediatric patient.