Department of Endocrinology, Instituto Nacional de Neurologia y Neurocirugia Manuel Velasco Suarez, Insurgentes Sur 3877 Col. La Fama, Mexico City, 14269, Mexico.
Pituitary. 2010 Sep;13(3):230-5. doi: 10.1007/s11102-010-0222-y.
ACTH-secreting tumors represent 10% of functioning pituitary adenomas, and most of them are microadenomas. It is generally accepted that only half of these tumors are correctly identified with current magnetic resonance imaging (MRI) techniques. The objective of the paper is to report a method for detecting suspected ACTH-secreting pituitary tumors undetectable by conventional dynamic MRI using dynamic 3-Tesla MRI (3T MRI) and half-dose gadopentetate dimeglumine (0.05 mmol/Kg). Eight patients were included (5 men and 3 women) with a mean age of 29.12 years. Each of them had a confirmed diagnosis of Cushing disease and a negative dynamic MRI for microadenoma using full-dose gadopentetate dimeglumine. A second MRI was then performed using only half the usual dose of contrast material. Images from the second MRI where compared with the first study. Microadenomas were detected in 100% of the patients using a half dose of the contrast. All were recognized on the basis of the presence of a hypointense nodular lesion surrounded by normal contrast-enhanced tissue. Six patients were submitted to surgery, and the results were confirmed by immunohistochemistry in all of them. The remaining subject had a sinus sample catheterization coincident with the MRI results.
A half dose of dynamic resonance imaging contrast material increases the sensitivity of MRI detection of ACTH-secreting pituitary tumors.
促肾上腺皮质激素分泌肿瘤占功能性垂体腺瘤的 10%，其中大多数为微腺瘤。人们普遍认为，目前的磁共振成像（MRI）技术只能正确识别其中一半的肿瘤。本文的目的是报告一种使用动态 3 特斯拉 MRI（3T MRI）和半剂量钆喷替酸二甲胺（0.05mmol/Kg）检测常规动态 MRI 无法检测到的可疑促肾上腺皮质激素分泌性垂体肿瘤的方法。8 例患者（5 例男性，3 例女性）纳入研究，平均年龄为 29.12 岁。他们每个人都被确诊为库欣病，且使用全剂量钆喷替酸二甲胺进行的动态 MRI 检查未发现微腺瘤。然后，仅使用一半的常规剂量造影剂进行第二次 MRI 检查。将第二次 MRI 的图像与第一次研究进行比较。在使用半剂量造影剂的情况下，100%的患者都检测到了微腺瘤。所有微腺瘤均根据存在被正常增强组织环绕的低信号结节性病变来识别。6 例患者接受了手术治疗，所有患者的结果均通过免疫组织化学得到了证实。其余患者的鼻窦样本与 MRI 结果一致。
使用半剂量动态磁共振成像造影剂可提高 MRI 检测促肾上腺皮质激素分泌性垂体肿瘤的灵敏度。
