Ripoll M Alemany, Raininko R
Department of Radiology, Uppsala University Hospital, Sweden.
Acta Radiol. 2002 Sep;43(5):464-73. doi: 10.1034/j.1600-0455.2002.430505.x.
To compare the detectability of small experimental intracranial haemorrhages on MR imaging at 0.5 T and 1.5 T, from hyperacute to subacute stages.
1 ml of autologous blood was injected into the brain of 15 rabbits to create intraparenchymal haematomas. Since the blood partially escaped into the cerebrospinal fluid (CSF) spaces, detectability of subarachnoid and intraventricular blood was also evaluated. MR imaging at 0.5 T and at 1.5 T was repeated up to 14 days, including T1-, proton density- and T2-weighted (w) spin-echo (SE), FLAIR and T2*-w gradient echo (GE) pulse sequences. The last MR investigation was compared to the formalin-fixed brain sections in 7 animals.
The intraparenchymal haematomas were best revealed with T2*-w GE sequences, with 100% of sensitivity at 1.5 T and 90-95% at 0.5 T. Blood in the CSF spaces was significantly (p < 0.05) better detected at 1.5 T with T2*-w GE sequences and detected best during the first 2 days. The next most sensitive sequence for intracranial blood was FLAIR. SE sequences were rather insensitive.
1.5 T equipment is superior to 0.5 T in the detection of intracranial haemorrhages from acute to subacute stages. T2*-w GE sequences account for this result but other sequences are also needed for a complete examination.
比较0.5T和1.5T磁共振成像（MR）在超急性期至亚急性期对小型实验性颅内出血的检测能力。
将1ml自体血注入15只家兔脑内以形成脑实质内血肿。由于部分血液逸入脑脊液（CSF）间隙，因此也对蛛网膜下腔和脑室内血液的可检测性进行了评估。在0.5T和1.5T条件下重复进行MR成像检查，持续14天，检查序列包括T1加权、质子密度加权和T2加权（w）自旋回波（SE）序列、液体衰减反转恢复（FLAIR）序列以及T2*加权梯度回波（GE）序列。将7只动物的最后一次MR检查结果与福尔马林固定的脑切片进行比较。
脑实质内血肿在T2加权GE序列上显示最佳，在1.5T时敏感性为100%，在0.5T时为90 - 95%。脑脊液间隙内的血液在1.5T时使用T2加权GE序列检测效果显著更好（p < 0.05），且在最初2天内检测效果最佳。对颅内血液次敏感的序列是FLAIR序列。SE序列相对不敏感。
在检测急性至亚急性期颅内出血方面，1.5T设备优于0.5T设备。T2*加权GE序列促成了这一结果，但完整检查还需要其他序列。
