|LETTER TO THE EDITOR
|Year : 2020 | Volume
| Issue : 2 | Page : 316-317
The sunburst sign
S Sheetal1, Ancil George Thomas2
1 Department of Neurology, Pushpagiri Institute of Medical Sciences and Research Centre, Thiruvalla, Kerala, India
2 Department of Neurology, Muthoot Hospital, Kozhencherry, Kerala, India
|Date of Submission||21-Oct-2020|
|Date of Decision||15-Nov-2020|
|Date of Acceptance||16-Nov-2020|
|Date of Web Publication||23-Dec-2020|
Dr. S Sheetal
16 FG, The Edge, Skyline Apartments, Thirumoolapuram, Thiruvalla - 689 115, Kerala
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Sheetal S, Thomas AG. The sunburst sign. Arch Med Health Sci 2020;8:316-7
A 74-year-old male with a history of Type 2 diabetes mellitus and systemic hypertension presented with the complaints of insidious-onset and gradually progressive memory impairment and slowness in walking for the past 3 months. He was noted to drag his left leg on walking. He denied any history of headache, vomiting, or seizures. On examination, he had evidence of frontal and temporal lobe dysfunction and spasticity of the left lower limb with left extensor plantar. Magnetic resonance imaging (MRI) of the brain showed a well-defined, extra-axial, dural-based, smoothly marginated, bi-lobed lesion, in the midline and parasagittal parieto-occipital region, straddling and mildly displacing the posterior falx toward the left side with invasion into the adjacent superior sagittal sinus [Figure 1]. Both the parasagittal components were seen displacing the adjacent brain parenchyma with an intervening cerebrospinal fluid (CSF) cleft [Figure 1d]. The lesion was noted to exhibit homogeneous T1-weighted hypointense, T2/T2 fluid-attenuated inversion recovery hyperintense signal, with near-homogeneous postcontrast enhancement. Adjacent bilateral parieto-occipital dura and the posterior falx showed smooth thickening and increased enhancement, suggestive of dural tail sign [Figure 1d]. Radial sunburst pattern was noted in the lesion on T2-weighted and postcontrast images, more prominent in the right-sided component [Figure 1]. All these features were suggestive of meningioma. He was referred for surgery.
|Figure 1: (a-c) Contrast-enhanced T1 sequences, axial, coronal, and sagittal sections, respectively, showing a dural-based, bi-lobed, homogenously enhancing lesion in the midline and parasagittal parieto-occipital region, right more than left, with a radial sunburst pattern (arrows). (d-f) Axial, coronal, and sagittal T2-weighted images showing the hyperintense bi-lobed lesion displacing the adjacent brain parenchyma with an intervening cerebrospinal fluid cleft (d, yellow arrow) and demonstrating the radial sunburst sign|
Click here to view
Meningiomas are the most common dural tumors. On computed tomography imaging, majority of meningiomas are hyperdense to the cortex and may show intratumoral calcification. Meningiomas are usually isointense to the cortex on all MRI sequences, however T2 hyperintensity may be seen in 50% of the cases, due to hypervascularity. They do not usually demonstrate diffusion restriction, and more than 50% cause perilesional vasogenic edema. A CSF cleft may be seen between the tumor body and the brain parenchyma. Most meningiomas demonstrate strong enhancement on postcontrast imaging and a dural tail sign is seen in up to 72% of cases, due to reactive thickening and enhancement of the dura. Dural metastatic lesions are typically hyperintense on T2 sequence, whereas lymphoma is typically isointense to hypointense in T2-weighted sequence. Other meningioma mimics include solitary fibrous tumors (SFTs) and melanoma, nonneoplastic processes such as tuberculosis and sarcoidosis, and autoimmune diseases such as immunoglobulin G4-related disease. The sunburst sign or spoke wheel appearance is a radiological sign seen in meningiomas., The sunburst sign refers to the characteristic vascular supply seen in some meningiomas, when seen tangential to the dural attachment. Dural branches of the external carotid artery, internal carotid artery, and vertebral artery may supply the tumor, and pial arteries may also become parasitized by the tumor. The feeder arterial branches diverge radially into the lesion, distributed like sunrays, giving the appearance of a sunburst on T2-weighted or postcontrast images, or during angiography. Low-grade SFTs, which mimic meningioma, may have “fluffy” contrast enhancement rather than a sunburst sign. Flow voids, described as absence of signal on MR images, caused by blood or cerebral spinal fluid flow, are seen in meningiomas and SFTs. Intracranial SFTs on MR images are reported to show a serpentine flow void, however a sunburst flow void is reported to be typical of meningioma. Meningeal hemangiopericytomas are aggressive versions of SFTs of the dura, and they also show multiple flow voids on MRI and a fluffy staining on angiography. On magnetic resonance spectroscopy, meningiomas exhibit high choline: creatinine ratio and low N-Acetyl Aspartate (NAA) peak. Alanine peak, if present, is characteristic. Meningiomas have many characteristic imaging features, one of which is the sunburst sign, which helps in differentiating from other dural-based pathologies.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Lyndon D, Lansley JA, Evanson J, Krishnan AS. Dural masses: Meningiomas and their mimics. Insights Imaging 2019;10:11.
Buetow MP, Buetow PC, Smirniotopoulos JG. Typical, atypical, and misleading features in meningioma. Radiographics 1991;11:1087-106.
Tokumaru A, O'uchi T, Eguchi T, Kawamoto S, Kokubo T, Suzuki M, et al.
Prominent meningeal enhancement adjacent to meningioma on Gd-DTPA-enhanced MR images: Histopathologic correlation. Radiology 1990;175:431-3.
Wang C, Xu Y, Xiao X, Zhang J, Zhou F, Zhao X. Role of intratumoral flow void signs in the differential diagnosis of intracranial solitary fibrous tumors and meningiomas. J Neuroradiol 2016;43:325-30.
Kunimatsu A, Kunimatsu N, Kamiya K, Katsura M, Mori H, Ohtomo K. Variants of meningiomas: A review of imaging findings and clinical features. Jpn J Radiol 2016;34:459-69.