【摘要】 目的评价磁共振弥散加权成像(DWI)和灌注加权成像(PWI)在急性脑缺血中的诊断价值。方法2例(23例急性脑梗死,4例TIA)发病24h以内急性脑缺血患者行MR扫描并采用平面回波技术作DWI及PWI检查,得到ADC图、CBV图及MTT图,分别测量缺血脑组织区与对侧正常脑组织区ADC值、rCBV值及MTT值,分别计算相对表观扩散系数比值(ADCR)、相对脑血流容量(rrCBV)、相对平均通过时间(rMTT)。结果22例急性脑梗死DWI上均表现高信号,1例稍高信号,4例TIADWI阴性。ADC值患侧(4.07±0.98)×10-4mm2/s,健侧(9.16±2.14)×10-4mm2/s,患侧低于健侧(t=2.16,P<0.05),ADC(-52.8±16.9)%。27例急性脑缺血rCBV患侧101.8±23.7,健侧204.±42.0,缺血区血流灌注少于健侧(t=2.13,P<0.05),rrCBV(-46.5±33.6)%;MTT患侧(2377.9±1814)s,健侧(1886.6±127.1)s,缺血区血流灌注时间长于健侧(t=2.22P<0.05),rMTT(24.2±23.3)%结论DWI和PWI联合运用,对急性脑缺血的早期诊断、血流灌注评价更全面、更正确,对临床制定治疗方案具重要价值。更多还原

【Abstract】 Objective To evaluate diagnostic value of diffusion-weighted imaging (DWI) and perfusion-weighted imaging(PWI) in acute cerebral ischemia. Methods 27 patients with acute cerebral ischemia not longer than 24h (23 patients with acute brain infarction, 4 with TIA) underwent MR scan. DWI and PWI were conducted using echo planar technique, obtaining ADC graphy, CBV graphy, and MTT graphy. Apparent diffusion coefficient (ADC) values, regional cerebral blood volume (rCBV) values and mean transmitting time (MTT) values in ischemic brain tissue and in opposite normal tissues were measured and calculated respectively. Results 22 patients with acute cerebral infarction showed high signal intensity and one patient showed slightly high signal intensity. 4 patients with TIA appeared normal in DWI. ADC value in ischemic part was (4.07 ± 0.98)× 10-4mm2/s, in healthy part was(9.16 ± 2.14)× 10-4mm2/s, higher than that of ischemic part (t = 2.16,P < 0.05). ADCR(-52.8 ± 16.9)%.Among 27 patients with acute ischemia in brain, rCBV in ischemic part was 101.8 ± 23.7,and in healthy part was 204.5 ± 42,more blood supply than that of in ischemic part (t = 2.13,P < 0.05), rCBV(-46.5 ± 33.6)%;MTT in ischemic part was(2377.9 ± 181.4)seconds and in healthy part was(1886.6 ± 127.1)seconds, shorter than that of in ischemic part (t = 2.22, P<0.05),rMTT(24.2±23.3)%. Conclusion A combined use of DWI and PWI is useful in giving a more complete and correct evaluation of acute cerebral ischemia, contributing much to plan a proper therapeutic resolution.更多还原