Brain MRI is helpful in the diagnosis of delayed puberty. Findings on MRI suggestive of delayed puberty include hypothalamo–pituitary lesions, aplasia of olfactory bulb and/or sulci (Kallmann syndrome), optic nerve compression (pituitary adenoma), and inner ear abnormalities (CHARGE syndrome). Aplasia of olfactory bulbs and/or sulci in MRI is the main differentiation of Kallmann syndrome from isolated hypogonadotropic hypogonadism, in the patient without smelling problems or hard to evaluate.

• Brain MRI is helpful in the diagnosis of delayed puberty. Findings on MRI suggestive of delayed puberty include:^[2]
  • Hypothalamo–pituitary lesions
  • Aplasia of olfactory bulb and/or sulci (Kallmann syndrome)
  • Optic nerve compression (pituitary adenoma)
  • Inner ear abnormalities (CHARGE syndrome)
• Brain MRI is indicated in patients with delayed puberty, experiencing some alarm signs, such as headache, visual impairment, and behavioral changes.
• Aplasia of olfactory bulbs and/or sulci in MRIis the main differentiation of Kallmann syndrome from isolated hypogonadotropic hypogonadism, in the patient without smelling problems or hard to evaluate.^[3]
• In hypogonadotropic hypogonadism, when the olfactory bulbs are absent in MRI the results of smell identification test (UPSIT) surely will show anosmia. While, when the olfactory bulbs are present in MRI, UPSIT may or may not show anosmia.^[4][3]

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  Pituitary adenoma – Case courtesy of A.Prof Frank Gaillard, via Radiopaedia.org^[1]
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  Hypothalamic lesion – Case courtesy of A.Prof Frank Gaillard, via Radiopaedia.org^[1]
• 
  Pituitary non-functioning macroadenoma – Case courtesy of A.Prof Frank Gaillard, via Radiopaedia.org^[1]
• 
  Kallman syndrome difference with normal brain – Case courtesy of A.Prof Frank Gaillard, via Radiopaedia.org^[1]

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