What is Leptomeninges and Pachymeninges?

The patterns of enhancement of the different layers of the meninges were divided into two types: leptomeningeal (pia and arachnoid), when enhancement of the meninges followed the convolutions of the gyri and/or involved the meninges around the basal cisterns; and pachymeningeal (dura), when the enhancement was thick …

What are Pachymeninges?

The pachymeninges (thick meninges) are the dura mater, which comprises two fused membranes derived from the embryonic meninx primativa: the periosteum of the inner table of the skull and a meningeal layer.

What does Pachymeningeal enhancement mean?

Abstract. Pachymeningeal enhancement, synonymous with dural enhancement, is a radiological feature best appreciated on a contrast-enhanced magnetic resonance imaging (MRI). The vasculature of the dura mater is permeable, facilitating avid uptake of contrast agent and subsequent enhancement.

What causes Pachymeningeal enhancement?

As the patient had resolving enhancement with no direct treatment of a CSF leak, it was presumed that the pachymeningeal enhancement was caused by meningeal venous hyperemia from venous collateral dilation post thrombus formation.

What’s new in imaging of the leptomeninges?

Imaging of the diseases of the leptomeninges has evolved. Contrast-enhanced T1-weighted MR imaging represented an advance over CT in depicting leptomeningeal diseases ( 1, 2 ). Fluid-attenuated inversion recovery (FLAIR) imaging has been known to be sensitive for parenchymal lesions ( 3 – 6 ).

Which intracranial tumors have a higher incidence of leptomeningeal spread?

Primitive neuroectodermal tumors (PNET, such as medulloblastoma), primary CNS lymphoma, and glioneuronal tumors have a much higher incidence of leptomeningeal spread. Other intracranial tumors can seed the leptomeninges producing so called drop metastases , tumors that deposit along the cord surface or in the cauda equina.

How many MR imaging studies are needed to detect leptomeningeal metastases?

METHODS: Sixty-eight patients referred for suspected leptomeningeal metastases underwent 74 MR imaging studies. The patients had either temporally related cytologic proof of leptomeningeal metastases or negative results of clinical follow-up confirming absence of leptomeningeal metastases.

What is a leptomeninges tumor?

In the spinal canal, the tumor deposits along the surface of the spinal cord attaching to the leptomeninges. The leptomeninges anatomically includes the arachnoid and pia mater. This may occur due to tumor originating outside or inside the central nervous system (CNS).