Fibroma MRI
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Diagnosis |
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Fibroma MRI On the Web |
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American Roentgen Ray Society Images of Fibroma MRI |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Simrat Sarai, M.D. [2]
Overview
MRI may be helpful in the diagnosis of fibroma. On MRI, fibromas appear isointense or hypointense on T1 sequences and hyperintense on T2 sequences.
MRI Findings
| MRI component | Features |
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Non-ossifying Fibroma
- MRI appearances of non-ossifying fibroma are variable and depends on when along the development and healing phase the lesion is imaged. Initially, the lesion has high or intermediate T2 signal, with a peripheral low signal rim corresponding to the sclerotic border. As it matures and begins to ossify, the signal becomes low on all sequences.
Contrast enhancement is also variable.
Ossifying Fibroma
MRI findings of ossifying fibroma includes the following:
- T1: low signal
- T2: iso-high signal
- T1 C+ (Gd): typically shows enhancement
Chondromyxoid Fibroma
MRI features of chondromyxoid fibromas are often not particularly specific. Signal characteristics include the following:
- T1: low signal
- T1 C+ (Gd)
- The majority (~70%) tend to show peripheral nodular enhancement
- Approximately 30% have diffuse contrast enhancement and this can be either homogeneous or heterogeneous
- T2: high signal
Desmoplastic Fibroma
There is considerable overlap with other bony lesions on MRI appearances of desmoplastic fibroma. Signal characteristics include the following:
- T1: typically low signal
- T2: has background intermediate to high signal with intrinsic low to intermediate intensity foci within 7
- T1 C+ (Gd): often shows heterogeneous enhancement
Cardiac Fibromas
Because of their dense, fibrous nature, the tumors are usually homogeneous and hypointense on T2-weighted MR images and isointense relative to muscle on T1-weighted images. Cardiac fibromas often demonstrate little or no contrast material enhancement.
Pleural Fibromas
Due to the fibrous component, signal characteristics tend to include the following:
- T1: typically low to intermediate signal
- T2: typically low signal overall (thought to be due to high cellularity and abundant collagen); areas of necrosis and myxoid degeneration can have high signal
- MRI may also show necrotic, haemorrhagic and cystic components in better detail if these entities are present.
Cemento-ossifying Fibroma
Although cemento-ossifying fibromas are composed of a mixture of calcified and non-calcified soft-tissue, as the later is predominantly fibrous, the whole mass is largely of low intensity on MRI.
- T1
- Intermediate to low signal
- Focal regions of higher signal may represent fatty marrow in ossified components
- T2:
- Low signal
- T1 C+ (Gd)
- Soft-tissue component may demonstrate some enhancement
Uterine Fibromas
MRI is not generally required for diagnosis, except for complex or problem-solving cases. It is, however, the most accurate modality for detecting, localizing and characterising fibroids. Size, location and signal intensity should be noted. Signal characteristics are variable and include the following:
- T1
- Non-degenerated fibroids and calcification appear as low to intermediate signal intensity compared with the normal myometrium
- Characteristic high signal intensity on T1 weighted images/an irregular, T1 hyperintense rim around a centrally located myoma suggests red degeneration, which is caused by **Venous thrombosis
- T2
- Non-degenerated fibroids and calcification appear as low signal intensity
- As they are usually hypervascular, flow voids are often observed around them
- Fibroids that have undergone cystic degeneration/necrosis can have a variable appearance, usually appearing high signal on T2 sequences.
- Hyaline degeneration is demonstrated as low T2 signal intensity
- Cystic degeneration, which is an advanced stage of intratumoral edema, also shows high signal intensity on T2 weighted images and does not enhance
- T1 C+ (Gd)
- Variable enhancement is seen with contrast administration
- Marked high signal intensity with gradual enhancement suggests myxoid degeneration
MRI is of significant value in the symptomatic patient when surgery and uterine salvage therapy is considered. It is also of great value in differentiating a pedunculated fibroid from an adnexal mass.