MRI Signal Measurement of Hippocampal Formation / 实用放射学杂志

ABSTRACT

Objective　To define the range of the normal values of MRI signals of hippocampal formation(HPF) for the diagnosis of early stage Alzheimer's disease and hippocampal sclerosis.Methods　MRI signals of 254 normal adults were measured on the transverse section.Results　HPF signal intensities wereT1 relaxation times,629±73 ms;T2 relaxation times,83±5.5 ms;and proton density value,5978±651.The T2 value range(χ±2S)was 72～94 ms,and mean 83 ms.T2 value greater than 104 ms will be associated with evidence of hippocampal pathologic changes.The mixed signal intensity of T2WI(30,60,120)were3907±407,2657±347,1288±174.The signal intensity ratios of T2WI were1.02,1.07,1.13.Conclusion　As for the histological features of temporal lobe cortex and HPF,T1relaxation times and proton density values are matched but T2 relaxation times of HPF are relatively longer.