The Clinical Applicantion Of MRI And ~1H-MRS On The Neonates With Hypoxic-Ischemic Encephalopathy

The incidence of Hypoxic-Ischemic Encephalopathy (HIE) in neonate is so high that it has threaten the life of neonate seriously, and HIE is one of the most common diease which induce disability in neonate, so it is very important to diagnose accurately and formulate treatment perscription as soon as possible. Magnetic resonance imaging (MRS) and 1H proton magnetic resonance spectroscopy (1H-MRS) coule reflect the region, scope and quality of pathological changes within brain exactly, and could also reflect the relationship with surrounding tissues. 1H-MRS has very important meaning in assaying pathogenetic condition and prognosis judgement.My investigation has analysed retrospectively changes of routine MR and 1H-MRS by 49 cases of HIE in neonate, compared with normal neonate. Reference with relative documents, intend to discuss the value of MRI and 1H-MRS in assaying the degree of brain injury in HIE, providing evidence for identifying patient's condition, guiding clinical therapy and judging prognose.Methods: Ahead of the examination of MRI and 1H-MRS, take the 10% Chloral Hydrate attenuated (Dosage: 50mg/kg) to put in the anus, and the operated when neonate have fall into sleep. All case were performed by SIEMENS 1.5T Avanto MR system, use the phased-array coil to complete MR scanning. Routine MR: transverse section scan included T1WI,T2WI,FLAIR, sagittal T2WI and coronal FLAIR scan. transverse T1WI scan use SE series: TR/TE=400/7.8ms; transverse T2WI scan use TSE series: TR/TE=3250/99ms; transverse FLAIR series: TR/TE=9000/109ms, TI=2500ms. the slice thickness was 5mm, the slice interval was 1.2mm, the matrix was 256×256, FOV: 230mm×230mm. Both team of HIE and normal contrast would take multi-voxle chemical shift imaging (CSI) 1H-MRS examination after the routine MR. 1H-MRS adopt the technic of point-resolved selective spectroscopy (PRESS), the region of interest (ROI) of 1H-MRS include both sides of basal nucleus, thalamencephal and part of frontal, parietal lobe's white matter. Scan series and parameters: TR/TE=1500/135ms, FOV:80mm×80mm, VOI: 40mm×40mm, stimulated time: 4, acquisition time: 7min12sec. The metabolism metered included: NAA, Cho, Cr and Lac. Using the software to be used specially for MRS on the Leonard's workstation to anlysis metabolism, and culculating resonance peak area and the ratio of different metabolism.Results: There were 2 neonates with HIE in severe group died after giving up therapy, others have received active treatment. All HIE neonates'CNS symptom have disappeared or have obviously improved, except 4 cases with Severe team. The main manifestaion of routine MR with HIE included: (1) hydrocephalus; (2) intracranial hemorrhage; (3) cortex and peri-encephalocoele white matter damage; (4) basal nuclei district and brain stem inury. In contrast, no abnormality seen in control group. And the incidence of the 4 pathology change in mild, medium and severe group which classified through imaging manifestation increased progressively by turns. The we have contrasted the imaging classification with clinical manifestaion, we discovered that imaging classification has a certain guiding significance to the long-term prognosis with HIE, but not absolutely positive correlation. The ratio of NAA/Cr in HIE group has obviously cut down to control group, but the ratio of Cho/Cr,Lac/Cr has obviously steped up. Compared the metabolism ratio of different level group, we have discovered the ratio of Lac/Cr has significant deviation in 3 group (p<0.05). Above the foundation, we divided to mild, medium and severe group according 1H-MRS, then we have found the ratio of NAA/Cr and Cho/Cr still alterd reciprocally according to the advanced of Lac/Cr. Compared the MRI classification with 1H-MRS graduation, the result indicated: the coincidence of 1H-MRS with MRI which belong to the medium and severe group is higher than mild group. And which display mild or normal in MRI, show more severe in 1H-MRS than MRI.Research Conclusion:1,Various kinds type of pathologic manifestation with HIE could display as different signs in MRI, especially more clear on T1WI.2,Routine MRI classification has a certain guiding significance to the long-term prognosis with HIE, but not absolutely positive correlation.3,The ratio of NAA/Cr in HIE group has obviously cut down to control group, but the ratio of Cho/Cr,Lac/Cr has obviously steped up.4,The Lac peak of Hypoxic-Ischemic focal step up is important identification to HIE, and the ratio of Lac/Cr is obviously correlated with pathogenetic condition.5,Compared with routine MR, 1H-MRS is more sensitive to Hypoxic-Ischemic, and could detect the extensional metabolism level within brain more promptly and susceptivly, and also could reflect more biochemical indicator from the quantitative point of view.6,combination of routine MR and 1H-MRS could reflect variation of morphous and metabolism objectively in HIE.