目的 探讨低磁场MRI对早期外伤性小灶性脑出血的诊断价值，为临床治疗提供参考依据。方法 对外伤后诊断为小 灶性脑出血的患者进行低磁场颅脑MRI平扫，扫描序列有横断位T1WI、T2WI、水抑制成像(FLAIR)及弥散加权成像 (DWI)。结果 在低磁场MRI中小灶性脑出血主要表现为T1WI为低、等信号或混杂信号，T2WI为高、等信号或混杂信 号，FIAIR与T2WI信号类似，但较T2WI更为敏感，弥散加权成像(DWI)为高低或等低混杂信号。结论 大部分早期小 灶性脑出血患者低磁场MRI所见与临床表现相符，低磁场MRI颅脑平扫可为外伤性小灶性脑出血患者提供影像学依 据，是颅脑CT检查表现为阴性患者必要的补充检查手段。

Objective To investigate the diagnosis value of traumatic focal cerebral hemorrhage in early stage by the low field MRI, in order to provide reference for clinical treatment. Methods A low magnetic field MRI was underwent in patients confirmed with focal cerebral hemorrhage after injury. Scan sequences such as axial T1WI, T2WI, FLAIR and DWI were included. Results By the low magnetic field MRI, low, equal or mixed signal was showed in T1WI, high or mixed signal in T2WI; FLAIR showed similar signal as T2WI but was more sensitive. DWI showed high-low or equal-low mixed signals. Conclusion Low field MRI findings for most of the early focal cerebral hemorrhage were consistent with the clinical manifestations. Low magnetic field MRI plain scan could provide traumatic focal cerebral hemorrhage with imaging evidence. Therefore, it was a necessary supplementary examination for traumatic patients whose CT examination showed negative.