Application value of magnetic resonance DWI high b-value and ADC value in hyperacute cerebral ischemia / 重庆医学

ABSTRACT

Objective To investigate the value of DWI high b value and ADC value in the diagnosis of hyperacute cerebral is-chemia.Methods Adult SD rats were selected and divided into the control and ischemic group by adopting the random number table method,the ischemic group was re-divided into 0.25,0.50,2.00,4.00、6.00 h groups according to the ischemic time,6 cases in each group with a total of 42 cases.The ischemic group conducted the right middle cerebral artery occlusion(MCAO)for performing the head T2WI and DWI scanning(b values were 0,400,800,2 000,3 000 s/mm2),the CNR and SNR values were recorded,rs-T2WI, rs-DWI and relative apparent diffusion coefficient(rADC)were measured.Then the imaging change of ischemic area was observed. The sensitivity and specificity were detected.Results In b=2 000 s/mm2and 3 000 s/mm2,the diagnostic rates of DWI for hyper-acute cerebral ischemia were obviously higher than those in b=400 s/mm2and 800 s/mm2,and when the b values were 400,800, 2 000,3 000 s/mm2,the sensitivities were 16.7%,50.0%,100.0% and 100.0% respectively and the specificities were 16.7%, 50.0%,100.0% and 100.0% respectively.The difference of ADC values under different b values had statistical significance(P<0.05).Conclusion High b value DWI in the diagnosis of hyperacute ischemia is significantly better than that of low b value,espe-cially in the aspect of displaying the lesion at 0.25,0.50 h cerebral ischemia.