Differential Diagnosis for Increased T2 Signal throughout Orbital Intraconal Fat
- Single Most Likely Diagnosis
- Idiopathic Orbital Inflammatory Disease (IOID): This condition is characterized by inflammation of the orbital tissues without a known cause. Increased T2 signal in the intraconal fat is a common finding due to edema and inflammation.
- Other Likely Diagnoses
- Thyroid Ophthalmopathy: This condition, associated with thyroid disease, can cause inflammation and edema in the orbital tissues, including the intraconal fat, leading to increased T2 signal.
- Orbital Cellulitis: An infection of the orbital tissues can cause increased T2 signal due to edema and inflammation.
- Sarcoidosis: This systemic disease can affect the orbit, causing granulomatous inflammation that may increase the T2 signal in the intraconal fat.
- Do Not Miss Diagnoses
- Orbital Malignancy (e.g., Lymphoma, Metastasis): Although less common, malignancies can infiltrate the orbital fat, causing increased T2 signal. Missing these diagnoses could have severe consequences.
- Infectious Processes (e.g., Abscess): An orbital abscess or other severe infections require prompt diagnosis and treatment to prevent serious complications, including vision loss and intracranial spread.
- Rare Diagnoses
- IgG4-Related Disease: A systemic condition that can cause inflammation in various parts of the body, including the orbit, leading to increased T2 signal in the intraconal fat.
- Granulomatosis with Polyangiitis (formerly Wegener's Granulomatosis): A rare autoimmune disorder that can affect the orbit and cause increased T2 signal due to inflammation.
- Orbital Histiocytosis: A group of rare disorders characterized by the proliferation of histiocytes in the orbit, which can lead to increased T2 signal in the intraconal fat.