Dynamic pituitary MRI has high sensitivity and specificity for the diagnosis of mild cushing's syndrome and should be part of the initial workup
Dynamic pituitary MRI has high sensitivity and specificity for the diagnosis of mild cushing's syndrome and should be part of the initial workup
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DOI：
10.1055/s-2007-980192
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发表时间：
2007-06-01
影响因子：
2.2
通讯作者：
Shahinian, H.
中科院分区：
文献类型：
--
作者：
Friedman, T. C.;Zuckerbraun, E.;Shahinian, H.
目的：轻度或发作性库欣综合征的诊断是困难的。标准测试包括24小时尿游离皮质醇（UFC）、夜间血液或唾液皮质醇测量和地塞米松抑制测试。由于敏感性和特异性较差，不建议将垂体影像学检查作为初始检查的一部分（仅用于帮助区分垂体库欣病和异位ACTH综合征）。随着动态垂体MRI的发展，即在钆静脉造影剂后使用多个冠状动态序列，我们假设MRI的敏感性和特异性将会提高，MRI将为库欣综合征的初步诊断提供有用的信息。方法：这是一个回顾性的图表回顾，检查了87例连续患者的图表，这些患者在一年的时间里在三级内分泌科诊所接受了库欣综合征的评估。大多数患者有轻度和/或发作性高皮质醇症。在这些患者中，24例最终通过生化检测（24小时UFC和尿17-羟基皮质激素，11例PM唾液皮质醇测量，晚间血浆皮质醇）诊断为垂体库欣综合征，22例排除库欣综合征诊断。所有患者均行动态垂体MRI （1.5 Tesla）检查。核磁共振成像的阅读者对诊断结果一无所知。结果：24例患者中有23例MRI显示垂体病变（21例为微腺瘤，2例为垂体不对称）。相比之下，在排除库欣组的20例患者中，只有3例（2例未进行MRI检查）在动态MRI上显示垂体病变。动态垂体MRI在所有检测方式中敏感性和阴性预测值最高，其特异性和阳性预测值与其他检测方法相似。结论：我们得出结论，几乎所有的库欣综合征患者在动态垂体MRI上都有病变，这一比例远高于非动态MRI报道的50-60%的比例。在我们库欣排除的患者组中，假阳性率为16%，与正常志愿者中10%的文献值相似，这是可以接受的，因为MRI不单独用作诊断的决定因素。虽然MRI阴性会错过肾上腺或异位库欣综合征的患者，但这些患者通常可以通过其他测试进行诊断。因此，这项初步研究表明，动态垂体MRI为库欣综合征的诊断提供了有价值的信息，应作为初始检查的一部分。
Aim: The diagnosis of mild or episodic Cushing's syndrome is difficult. The standard tests include 24-hour urinary free cortisol (UFC), night-time blood, or salivary cortisol measurements, and dexamethasone suppression tests. Imaging studies of the pituitary have not been recommended as part of the initial workup (only to help distinguish pituitary Cushing's disease from the ectopic ACTH syndrome) because of poor sensitivity and specificity. With the development of dynamic pituitary MRI which uses multiple coronal dynamic sequences following gadolinium intravenous contrast, we hypothesized that the sensitivity and specificity would be increased and MRI would provide useful information for the initial diagnosis of Cushing's syndrome.Methods: This was a retrospective chart review examining charts from 87 consecutive patients who were evaluated for Cushing's syndrome in a tertiary Endocrinology clinic over a one-year period. Most patients had mild and/or episodic hypercortisolism. Of these patients, 24 eventually were diagnosed with pituitary Cushing's syndrome by biochemical testing (24-h UFC and urinary 17-hydroxycorticosteroids, 11 PM salivary cortisol measurements, evening plasma cortisol), and 22 had the diagnosis of Cushing's syndrome excluded. Dynamic pituitary MRI (1.5 Tesla) was performed on all patients. The reader of the MRI was blind to the diagnosis.Results: Twenty-three of 24 patients had a MRI consistent with a pituitary lesion (21 with a microadenoma, two with pituitary asymmetry). In contrast, only 3 of 20 patients (2 patient did not have MRIs) in the Cushing's excluded group had a pituitary lesion on dynamic MRI. Dynamic pituitary MRI had the highest sensitivity and negative predictive value of any testing modalities and its specificity and positive predictive value were similar to that of other tests.Conclusion: We conclude that almost all patients in this series with Cushing's syndrome have a lesion on dynamic pituitary MRI, a rate much higher than the 50-60% rate reported for non-dynamic MRIs. The false positive rate of 16% in our group of Cushing's excluded patients is similar to the literature value of 10% seen in normal volunteers and is acceptable since MRI is not used solely as a determinant for the diagnosis. While a negative MRI will miss those patients with adrenal or ectopic Cushing's syndrome, those patients can usually be diagnosed by other testing. Thus this preliminary study implies that dynamic pituitary MRI adds valuable information to assist in the diagnosis of Cushing's syndrome and should be ordered as part of the initial workup.