Hayashi S, Ito K, Shimada M, Tsubuku M, Kaneko I, Kogure T, Kusama K, Nanba T, Senoh A, Tsuchida S
First Department of Radiology, Toho University School of Medicine, Tokyo, Japan.
Radiat Med. 1995 Jul-Aug;13(4):167-70.
Magnetic resonance (MR) imaging of pituitary adenoma is usually carried out in dynamic studies with bolus contrast material injections, with the result that few strong images are obtained. Dynamic studies using a slowly injected contrast material were carried out in 14 cases of pituitary adenomas. The examinations were performed with a 1.5 Tesla superconducting MR imaging system using the spin-echo technique. Gd-DTPA (0.1 mmol/kg) was slowly injected (within 90 sec) by hand, providing seven to nine dynamic images during 350 sec from the start of injection. The average time to reach the maximum signal intensity was 170.6 sec in adenoma and 156.2 sec in normal gland tissue. The maximum contrast signal intensity ratio of adenoma to normal gland was 0.527 in the fifth image. The contrast of adenoma to normal gland tissue was calculated by the following formula: ASII (adenoma signal intensity index) = (adenoma signal intensity-tissue signal intensity)/tissue signal intensity. The most remarkable contrast between adenoma and normal tissue was obtained from the fourth to eighth images. In other words, we could obtain the strongest contrast at 144.8 sec to 299.6 sec from the start of contrast injection. Our results with slow injection suggest that stronger images can be obtained a longer period after contrast injection.
垂体腺瘤的磁共振（MR）成像通常在团注对比剂的动态研究中进行，结果只能获得少数清晰的图像。对14例垂体腺瘤患者进行了使用缓慢注射对比剂的动态研究。检查使用1.5特斯拉超导MR成像系统，采用自旋回波技术。手动缓慢注射钆喷酸葡胺（0.1 mmol/kg）（在90秒内），从注射开始350秒内提供7至9幅动态图像。腺瘤达到最大信号强度的平均时间为170.6秒，正常腺组织为156.2秒。在第五幅图像中，腺瘤与正常腺的最大对比信号强度比为0.527。腺瘤与正常腺组织的对比通过以下公式计算：ASII（腺瘤信号强度指数）=（腺瘤信号强度 - 组织信号强度）/组织信号强度。腺瘤与正常组织之间最显著的对比出现在第四至第八幅图像中。换句话说，从对比剂注射开始144.8秒至299.6秒时可获得最强对比。我们缓慢注射的结果表明，在对比剂注射后较长时间可以获得更清晰的图像。
