{"id":3302597,"date":"2022-01-23T17:14:00","date_gmt":"2022-01-23T22:14:00","guid":{"rendered":"https:\/\/myendoconsult.com\/learn\/?p=3302597"},"modified":"2023-03-16T05:55:26","modified_gmt":"2023-03-16T10:55:26","slug":"prolactinoma-mri","status":"publish","type":"post","link":"https:\/\/myendoconsult.com\/learn\/prolactinoma-mri\/","title":{"rendered":"Prolactinoma MRI"},"content":{"rendered":"

Prolactinomas<\/a><\/strong>\u00a0 represent the monoclonal proliferation of lactotroph cells resulting in the formation of an adenoma. Although inheritable courses of pituitary adenomas exist, such as multiple endocrine neoplasia type I<\/a>, most prolactinomas occur due to sporadic mutations.<\/p>\n

Prolactin secreting microadenomas<\/strong> (\u2264 10 mm in largest diameter) usually present with second-degree hypogonadism (amenorrhea in women and low libido in men) with or without galactorrhea.<\/p>\n

Macroadenomas<\/strong> representing tumors greater than 10 mm in size are more likely to present with mass effect symptomatology, including headaches, cranial nerve palsies, and visual field defects.<\/p>\n

Anatomical relations of the Pituitary Gland<\/h2>\n

The hypophysis<\/a> is an ovoid-shaped, reddish-gray gland measuring 12mm x 8mm in its transverse and anterior-posterior dimensions, respectively. The gland measures about 6mm in it\u2019s cranio-caudal distance. The hypophysis sits on the floor of the\u00a0sellar turcica<\/strong>\u00a0and is bound on its superior aspect by the optic chiasm. It is bound laterally by the cavernous sinus and anterior-inferiorly by the sphenoid sinus. Finally, the gland is shielded posteriorly by the posterior wall of the sella turcica, pons, and posterior\u00a0intercavernous<\/em>\u00a0sinus.<\/p>\n

\"Anatomical<\/p>\n

MRI of the pituitary gland (coronal section) showing its relevant anatomical relationships<\/p>\n

\"Coronal<\/p>\n

Coronal section of the pituitary gland showing the relations of the cavernous sinus to the hypophysis<\/p>\n

MRI findings<\/h2>\n

T1-weighted magnetic resonance imaging (MRI), with coronal and sagittal images before and after administering intravenous gadolinium, is critical in identifying prolactinomas and pituitary adenomas in general. High-resolution contrast-enhanced T1-weighted images of the pituitary gland classically show a hypointense (dark) lesion consistent with an adenoma (prolactinoma)<\/a>. It is worth noting that normal pituitary tissue has a homogenous enhancement (brightness)on T1-weighted images1<\/sup>.<\/p>\n

The signal intensity of solid prolactinomas on T2-weighted images can be used to group prolactinomas into two groups \u2013 homogeneous or heterogeneous. To estimate the T2 signal intensity<\/strong> of a prolactinoma, a circular region of interest<\/strong> (ROI) tool is utilized in comparing the tumor to gray matter (e.g., temporal gray matter. A T2 weighted intensity ratio (Tumor : Gray matter) lower than 1.0 is hypo<\/strong> or isointense<\/strong>.<\/p>\n

Conversely, an intensity ratio >1.0 is hyperintense<\/strong>. Furthermore, cystic prolactinomas have unusually bright intensity on T2 weighted images2<\/sup>. The diagnostic yield of pituitary magnetic resonance imaging for prolactinomas increases with raising serum prolactin levels, usually above 100 ng\/ml3<\/sup>.<\/p>\n

Samples of prolactinomas noted on MRI<\/h2>\n

\"\"<\/p>\n

Microprolactinoma on T1-weighted images (post-gadolinium administration). The arrow shows a hypointense lesion (prolactinoma) superimposed on a hyperintense background (normal pituitary tissue). Image Courtesy (A. Quarde)<\/p>\n

References<\/h2>\n
    \n
  1. Chaudhary, V. & Bano, S. Imaging of the pituitary: Recent advances. Indian J. Endocrinol. Metab.<\/em> 15<\/strong>, S216\u2013S223 (2011).<\/li>\n
  2. Burlacu, M. C., Maiter, D., Duprez, T. & Delgrange, E. T2-weighted magnetic resonance imaging characterization of prolactinomas and association with their response to dopamine agonists. Endocrine<\/em> 63<\/strong>, 323\u2013331 (2019).<\/li>\n
  3. Rand, T. et al.<\/em> MRI of microadenomas in patients with hyperprolactinaemia. Neuroradiology<\/em> 38<\/strong>, 744\u2013746 (1996).<\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"

    Prolactinomas\u00a0 represent the monoclonal proliferation of lactotroph cells resulting in the formation of an adenoma. Although inheritable courses of pituitary adenomas exist, such as…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[53,94],"tags":[],"class_list":["post-3302597","post","type-post","status-publish","format-standard","hentry","category-endocrine-disease-pituitary-gland","category-endocrine-reviews-pituitary"],"_links":{"self":[{"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/posts\/3302597","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/comments?post=3302597"}],"version-history":[{"count":22,"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/posts\/3302597\/revisions"}],"predecessor-version":[{"id":4415944,"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/posts\/3302597\/revisions\/4415944"}],"wp:attachment":[{"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/media?parent=3302597"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/categories?post=3302597"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/tags?post=3302597"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}