Dot in a circle sign
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Mycetoma
foot. Main hypointense lesion of soft tissues of the second finger. No intralesional Doppler signal.
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Mycetoma
foot. Numerous small lesions of low intensity in T1 (left image). After contrast (right image) we can see those numerous enhancing lesions containing small low-foci. The lesions are separated by tissue of low signal intensity.
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Mycetoma
foot. Multiple lesions with faint central foci of low signal intensity tissue.
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Mycetoma
foot. Hypointense mass with small nodular hyperintense lesions surrounding the second finger of the left foot.
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Dot in a circle sign is an MRI sign for maduromycosis or mycetoma.
It is described as a classic appearance on T2 weighted images which show a small rounded hyperintensity (representing granulation tissue), surrounded by a low signal intensity rim (representing fibrous septa) with a hypointense dot (representing susceptibility loss due to fungi) in the center .
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