Aronen H J, Niemi P, Kwong K K, Pardo F S, Davis T L
Department of Radiology, Massachusetts General Hospital, Charlestown, USA.
Acta Radiol. 1998 Sep;39(5):474-81. doi: 10.1080/02841859809172210.
To study T1 relaxation times in brain tumors before and after paramagnetic contrast medium injection.
Seventeen patients with a known or suspected brain tumor were studied with an echo planar inversion recovery imaging sequence using 10 different inversion times. Double injections of Gd chelate (0.1 mmol/kg + 0.2 mmol/kg) were administered in 5 patients, and a single 0.2-mmol/kg dose in 12 patients.
After the 0.2-mmol/kg dose, T1 decreased from 1121 +/- 130 ms to 987 +/- 103 ms in gray matter (p < 0.001), and from 666 +/- 29 ms to 646 +/- 27 ms in white matter (p < 0.001). Tumor T1 shortened from 1515 +/- 319 ms to 717 +/- 383 ms. After the 0.1-mmol/kg dose (n = 5), tumor T1 decreased from 1116 +/- 261 ms to 793 +/- 202 ms and after the additional 0.2-mmol/kg dose it decreased further to 526 +/- 141 ms.
Postcontrast T1 relaxation times in tumors showed considerable variation and remained, on average, relatively long compared to white matter. This should be taken into account when deciding which pulse sequences, imaging parameters, and contrast agent doses are optimal for brain tumor imaging.
研究顺磁性造影剂注射前后脑肿瘤的T1弛豫时间。
对17例已知或疑似脑肿瘤患者采用回波平面反转恢复成像序列进行研究，使用10种不同的反转时间。5例患者进行了两次钆螯合物注射（0.1 mmol/kg + 0.2 mmol/kg），12例患者进行了一次0.2 mmol/kg剂量的注射。
注射0.2 mmol/kg剂量后，灰质的T1从1121±130 ms降至987±103 ms（p < 0.001），白质的T1从666±29 ms降至646±27 ms（p < 0.001）。肿瘤的T1从1515±319 ms缩短至717±383 ms。注射0.1 mmol/kg剂量后（n = 5），肿瘤的T1从1116±261 ms降至793±202 ms，在额外注射0.2 mmol/kg剂量后进一步降至526±141 ms。
肿瘤的造影后T1弛豫时间显示出相当大的变化，与白质相比，平均而言仍相对较长。在决定哪些脉冲序列、成像参数和造影剂剂量最适合脑肿瘤成像时，应考虑到这一点。
