CT analysis of intrasellar pituitary adenomas with emphasis on patterns of contrast enhancement

Abstract

Analysis of the computed tomograms of 85 purely intrasellar pituitary adenomas documents a highly variable pattern of response to contrast enhancement. Twenty-eight of 85 adenomas exhibited homogeneously increased density. Twenty exhibited heterogeneously increased, patchy or ringlike density; 16, hypodensity; and 8, isodensity with normal pituitary tissue. In 13 patients the predominant CT finding was an empty sella with variable enhancement of the adenoma and residual pituitary tissue. Pathological specimens demonstrated that the hypodense zones observed within pituitary microadenomas may represent pituitary necrosis, cyst, hemorrhage, intratumoral abscess, relatively less intense enhancement than the normal surrounding pituitary tissue.

The diagnostic accuracy of preoperative CT scanning in the evaluation of pituitary ACTH-secreting adenomas

“…In recent years, high-resolution CT of the sella turcica has almost completely replaced all other imaging techniques in the investigation of abnormalities of the pituitary gland. However, there is scant information about the diagnostic accuracy of this procedure, especially in regard to the identification of adenomas in Cushing's disease [1][2][3][4][5][6] . Over a period of 5 years between 1980 and 1985, 35 patients who had coronal CT scans of the sella turcica at the Montreal General Hospital for suspected ACTH-secreting adenoma underwent transsphenoidal ex ploration.…”

Comparison of MR Imaging and CT in Pituitary Macroadenomas

“…Thus, they may be attributed to the presence of areas of necrosis or accumulations of small (microscopic?) cysts, a possibility which is compatible with the absence of enhancement in the majority of cases (8). Cysts containing some substance producing Tl shortening, e.g.…”

Dynamic computed tomographic evaluation of the pituitary gland in healthy dogs

“…5,6,8,10 However, microadenomas that do not affect the size and shape of the pituitary gland may not be detected because of isoattenuation of the adenoma tissue and the surrounding unaffected pituitary tissue. [11][12][13][14] In humans, microadenomas have been identified by use of dynamic CT. 7,15,16 Dynamic contrast-enhanced CT includes a series of scans of identical slice thickness at the same slice position through the center of the pituitary gland during and after IV injection of a bolus of contrast medium. 6,7,15 During dynamic CT in humans, enhancement of the internal carotid artery is observed followed by enhancement of the central part of the secondary capillary bed of the adenohypophysis, which has been called the pituitary tuft.…”