Application of combined enhanced T2 star weighted angiography and diffusion tensor imaging in diagnosis of hypoxic-ischemic encephalopathy

LI Bo; YUAN Yuxin; WANG Ke

doi:10.19300/j.2018.L4627

Abstract：Objective To explore value of the combined application of enhanced T2 star weighted angiography (ESWAN) and diffusion tensor imaging in diagnosis of hypoxic-ischemic encephalopathy(HIE). Methods Forty infants with HIE in our hospitial during January 2012 to January 2015 were chosen as the observation group, and 20 cases of normal full-term newborns admitted in the same period were chosen as control group. There was no significant difference in examination time and gestational age between the two groups (P>0.05). They underwent conventional T1WI, T2WI, ESWAN, and DTI scans, the number of hemorrhage foci was measured and the differences in R2*value, phase value, and anisotropy fraction (FA) between the two groups were compared with t-test. Results ESWAN and MRI showed that the main sites of hemor-rhage were brain stem, frontal lobe, occipital lobe, temporal lobe, subependymal space, ventricle, cerebellum, and subarach-noid space. The manifestations of hemorrhage included, 1) the parenchymal and subependymal hemorrhage on the conven-tional MRI showed striped, mild hypointensity or isointensity on T1WI, and mild hyperintensity or hypointensity on T2WI. In the 17 cases with hemorrhage, the ESWAN could detect more hemorrhage foci and larger volume than the conventional MRI. The boundary of the hemorrhage was more clear on the ESWAN than on conventional MRI. Small hemorrhage could be de-tected on the ESWAN, but not on conventional MRI in 3 cases. 2) The ventricular hemorrhage on the conventional MRI showed round shape, and iso-or mild hyperintensity on T1WI, and ios-or mild hyporintensity on T2WI. While, the hemor-rhage showed patchy or spotted hypointensity with demarked border on the ESWAN. 3) The subarachnoid hemorrhage in the temporal or occipital areas showed striped mild hyperintensity on T1WI and blurry on T2WI on the conventional MRI, but showed linear low signal shadow on the ESWAN. In the observation group of 40 children, a total of 173 lesions were detected by ESWAN, including 107 hemorrhagic lesions (61.8％) and extensive white matter damage or edema. And 173 lesions were detected by conventional MRI, including 75 hemorrhagic lesions (43.4％)with the lesions. The R2*value in observation group was significantly higher (P<0.05), but phase and FA values were significantly lower than that in the control group (P<0.05). Conclusion ESWAN is sensitive and accurate in detecting hemorrhage in HIE patients, while DTI is sensitive in detecting white matter injury. The combination of the two technologies can accurately assess HIE brain injury.