Hamon-Kérautret M, Leclerc X, Dewailly D, Pruvo J P, Fossati P, Clarisse J
Department of Neuroradiology, Hôpital B, C.H.R.U. Lille, France.
Eur J Radiol. 1994 Aug;18(3):185-90. doi: 10.1016/0720-048x(94)90332-8.
We report our experience with magnetic resonance imaging at 0.5 Tesla in the radiological diagnosis of pituitary adenomas.
Over 2 years we performed a prospective study in 38 patients with pituitary microadenomas to assess the potential additional benefit of gadolinium in the detection of small intrasellar lesions. The protocol included three coronal T1-weighted sequences: precontrast, early postcontrast (obtained less than 2 min after injection) and late postcontrast (obtained 5 min after injection). For each sequence lesions were classified according to their visibility into three categories: definite lesion, probable lesion or absent lesion.
Lesions were classified as well-defined in 55% of patients on the precontrast study, 89.5% on the early postcontrast study and 60.5% on the late postcontrast study. Of nine microadenomas not detected on the precontrast scans, all were clearly seen on the early post contrast scans; only four were well-defined on the late postcontrast study. Only one lesion was not seen on the early postcontrast study but was well-defined on precontrast study as a spontaneous high-intensity focal area: it was a hemorrhagic microadenoma.
Our results suggest that the early postcontrast study is the most useful sequence for the detection of microadenomas. Precontrast image is necessary to detect hemorrhagic lesions; the late postcontrast sequence has a low additional diagnostic yield and seems unnecessary unless the other sequences are inconclusive.
我们报告在0.5特斯拉磁共振成像用于垂体腺瘤放射诊断方面的经验。
在两年多的时间里，我们对38例垂体微腺瘤患者进行了一项前瞻性研究，以评估钆剂在检测鞍内小病变方面可能带来的额外益处。检查方案包括三个冠状面T1加权序列：平扫、早期增强扫描（注射后不到2分钟获得）和延迟增强扫描（注射后5分钟获得）。对于每个序列，根据病变的可见性将其分为三类：明确病变、可能病变或无病变。
在平扫研究中，55%的患者病变显示清晰；在早期增强扫描中，这一比例为89.5%；在延迟增强扫描中为60.5%。在平扫未检测到的9个微腺瘤中，所有在早期增强扫描中均清晰可见；在延迟增强扫描中只有4个显示清晰。在早期增强扫描中仅1个病变未显示，但在平扫中作为自发高信号灶显示清晰：这是一个出血性微腺瘤。
我们的结果表明，早期增强扫描是检测微腺瘤最有用的序列。平扫图像对于检测出血性病变是必要的；延迟增强扫描序列的额外诊断价值较低，除非其他序列结果不明确，否则似乎没有必要。
