PMC7609909_01
(A) Axial T2-weighted imaging showed multiple heterogeneous hypersignal nodules with central spots of hyposignal (arrows) in the right temporal lobe and significant edema around the lesion. (B) Axial T1-weighted imaging revealed the heterogeneous hyposignal nodules. (C) Diffusion-weighted imaging revealed slight hyperintense nodules. (D) Axial and (E) sagittal T1-weighted images with contrast demonstrated the enhancing nodules arising from the meninges, with significant perilesional edema. (F) Coronal T1-weighted images with contrast showed the mass effect of the nodules, which led to the compression of the right lateral ventricle and evident midline shift. (G) Post-operative CT showed that no nodules with a certain amount of hypodense edematous zone could be found on the right temporal lobe.
fnins-14-544802-g001.jpg
PMC7609909_01_fnins-14-544802-g001.jpg
F1
MR machine's individual configuration software was applied to complete the correction of the baseline, identification of each compound, and analysis of peak value and ratio of each compound. MRI (Figures 1A-C) revealed multiple nodules with evident perilesional edema in the right temporal lobe, which was characterized by hypointensity on T1-weighted images, mostly hyperintensity on T2-weighted images, and slight hyperintensity on diffusion-weighted imaging. Contrast-enhanced T1-weighted images (Figures 1D-F) showed significant enhancement of the nodules and adjacent meninges ("dural tail"). The post-op CT (Figure 1G) showed no nodules, and a certain amount of hypodense edematous zone could be found on the right temporal lobe.
(A) Positioning image of single-voxel magnetic resonance (MR) spectroscopy. (B) MR spectroscopy [echo time (TE) 35 ms] revealed a slightly increased choline (Cho) peak and a moderate decrease in the peaks of creatine (Cre) and N-acetylaspartate (NAA). A lipid/lactate peak was observed at 0.9 and 1.3 ppm. (C) MR perfusion reflected that the cerebral blood flow of the nodules (arrow) was lower than that of the contralateral hemisphere, and significant low perfusion was observed in the edema area.
fnins-14-544802-g002.jpg
PMC7609909_01_fnins-14-544802-g002.jpg
F2
Single-voxel MR spectroscopy with an echo time of 35 ms (Figures 2A,B) revealed a slightly increased choline (Cho) peak and a slight decrease in the peaks of creatine (Cr) and N-acetylaspartate (NAA). MRI (Figure 2C) suggested that regional CBF in the nodule area was lower than that of the contralateral normal regions, with the highest relative CBF value of 0.84 in the lesion area, while the edema area around the lesion presented less perfusion. Merely based on the clinical manifestations, laboratory results, and conventional MR images, the diagnosis of inflammatory granuloma should be first suspected, while a differential diagnosis including neoplastic lesions such as meningiomas and brain metastasis should also be considered.
Histopathology showed granulation tissue with ischemic necrosis surrounded by multinucleated giant cells, plasmacytes, and lymphocytes (HE staining, original magnification x100).
fnins-14-544802-g003.jpg
PMC7609909_01_fnins-14-544802-g003.jpg
F3
Post-operative pathology (Figure 3) revealed granulation tissue with ischemic necrosis surrounded by multinucleated giant cells, plasmacytes, and lymphocytes.