Figures
Figure 1A
(A) MRI findings of patients with confirmed FCD and T2 * signal changes; 7T T 2 (A-D), T 2 * (E-H) and T 2 * minimum intensity projection (I-L) transverse reconstructions. Lesions are depicted in detail in (B), (D), (F), (H), (J) and (L). Patient I; FCD ILAE type IIb (A, B, E, F, I, J). No lesion was identified on 3T MRI and subtle grey-white matter junction blurring was seen on 7T T 2 weighted MRI (A, B). On T 2 * (E, F), the neighbouring sulcus appears to contain prominent vasculature. T 2 * minimum intensity projection (I, J) aids in the visual detection. Patient II; FCD ILAE type Ib (C, D, G, H, K, L). T 2 -weighted MRI (C, D) shows grey-white matter junction blurring and cortical thickening indicative of FCD.In the same area, T 2 * (G, H) shows a wide sulcus with prominent vascular structures. T 2 * minimum intensity projection (K, L) strongly emphasizes the increased vasculature.
Figure 1A
Figure 1B
(B)MRI findings of patients with confirmed FCD and T 2 * signal changes. 7T T 2 (A-D), T 2 * (E-H), and T 2 * minimum intensity projection (I-L) coronal reconstructions. Lesions are depicted in detail in (B), (D), (F), (H), (J) and (L). Patient III; mild malformation of cortical development type 2 (A, B, E, F, I, J). On T 2 (A, B), blurring and subcortical hyperintensity represent developmental malformation. T 2 * (E, F) shows a wide Sylvian fissure but no clearly appreciable vascular changes. On T 2 * minimum intensity projection (I, J), there appears to be an increase in vascular signal in the superior temporal pole. Patient IV (C, D, G, H, K, L); FCD ILAE type IIb. On T 2 (C, D), there is a notable large central parasagittal extracerebral space containing a large vein, but without evident dysplastic characteristics, however, on T 2 * (G, H), the large vein and smaller vasculature that drains from the dysplastic cortex (as confirmed by histological examination) is observed. (K, L) Image enhancement on T 2 * minimum intensity projection.
Figure 1B
Figure 2
Histology. (A) Normal neocortex (HE: haematoxylin and eosin). (B-C) HE and (D) CD34 of neocortex from Patient III with thick (focally fibrotic) leptomeninges and prominent vascular structures. (E-F) NeuN of neocortex from Patient III without cortical dyslamination, but with microscopic neuronal clusters (arrow; insert in F) and excess of neurons of normal morphology in the deep white matter (isolated mild malformations of cortical development; mMCD type 2). Scale bar inA, B, E, F: 320 μm; C, D: 160 μm.
Figure 2
Figure 3
Transverse 7T T 2 * images of a healthy subject. T 2 * -weighted images showing transverse slices parallel to the anterior commissure-posterior commissure line at the level of the foramen of Monroe (A) and at the level of the cingulate sulcus (B). (A, B) Minimum intensity projections with 5-mm slab thickness at the level of (C) and (D), respectively. These images show the normal appearance of venous cerebral vasculature in a healthy subject.
Figure 3
Tables
Authors
1 Department of Neurology and Neurosurgery, Brain Center Rudolg Magnus, University Medical Center Utrecht
2 Department of Radiology, University Medical Center Utrecht
3 Department of Pathology, University Medical Center Utrecht
4 Academic Medical Center, Department of Pathology, Amsterdam, The Netherlands
* Correspondence: Tim J. Veersema
Universitair Medisch Centrum Utrecht,
Internal post number G03.232,
PO Box 85500,
3508 GA Utrecht, The Netherlands
Focal cortical dysplasia is one of the most common underlying pathologies in patients who undergo surgery for refractory epilepsy. Absence of a MRI-visible lesion necessitates additional diagnostic tests and is a predictor of poor surgical outcome. We describe a series of six patients with refractory epilepsy due to histopathologically-confirmed focal cortical dysplasia, for whom pre-surgical 7 tesla T 2 *- weighted MRI was acquired. In four of six patients, T 2 * sequences showed areas of marked superficial hypointensity, co-localizing with the epileptogenic lesion. 7 tesla T 2 * hypointensities overlying focal cortical dysplasia may represent leptomeningeal venous vascular abnormalities associated with the underlying dysplastic cortex. Adding T 2 * sequences to the MRI protocol may aid in the detection of focal cortical dysplasias.