Table 6 MR imaging pattern for extra sinus extension
From: Magnetic resonance imaging features of post-COVID-19 regional and invasive sino-nasal mucormycosis
Pattern of extra-sinus extension | N (%) | MRI features |
|---|---|---|
Maxilla-facial soft-tissue | ||
Pre-antral soft tissue | 43 (69.35) | Infiltration of the implicated soft-tissue spaces with fat stranding was primarily seen on T1 W, T2 W, fat-saturated T2W and postcontrast T1W images |
Retro-antral fat | 33 (53.23) | |
Pterygopalatine fossa | 47 (75.8) | |
Infra-temporal fossa | 22 (35.48) | |
Pre-septal space | 30 (48.39) | |
Buccal space | 5 (8.06) | |
Maxillo-facial bones | ||
Anterior maxillary and zygomatic bone | 2 (3.23) | Marrow edema and enhancement of the affected bones manifested primarily in fat-saturated T2W and postcontrast T1W images, respectively |
Maxillary process of palatine bone | 6 (9.68) | |
Orbit | ||
Intraorbital intra-conal fat | 12 (19.35) | T1W, fat-saturated T2W, and postcontrast T1W images showed retrobulbar fat stranding/edema and enhancing soft tissue in the orbit with or without extraocular muscle involvement |
Intraorbital intra-conal soft tissue extension | 8 (12.9) | |
Including extra-ocular muscles | 7 (11.29) | |
Orbital apex | 6 (9.68) | |
Optic nerve | 5 (8.06) | Optic nerve infarction is indicated by diffusion restriction within the nerve |
Skull base | 5 (8.06) | Bone marrow signal changes at the affected Clivus and pterygoid bones, along with marrow edema and enhancement, were most noticeable in fat-saturated T2W and postcontrast T1W images, respectively |
Intracranial | ||
Cavernous sinus thrombosis | 5 (8.06) | Abnormal signal intensity of the affected cavernous sinus, with abnormal enhancement, manifested mainly in fat-saturated T2W and postcontrast T1W images |
ICA narrowing/occlusion | 3 (4.84) | MR angiography and postcontrast T1W images demonstrated internal carotid artery constriction without or with arterial wall enhancement |
Epidural/subdural collections | 4 (6.45) | Epidural/sub-dural collections, with meningeal enhancement |
Focal cerebritis | 3 (4.84) | Cerebral parenchymal signal alterations with peripheral enhancement appreciated in T2W, diffusion-weighted and postcontrast T1W images indicating cerebral parenchymal invasion/abscess development |
Cerebral infarction | 3 (4.84) | Cortical and subcortical T2 and FLAIR hyperintense area with restricted diffusion following the vascular territory or in the watershed area indicating acute infarction |