407.Newborn myelination

每天朗读一段医学影像学英语文章

Figure 12A. Axial T1W SE image of the neonatal brain. Contrast between hypointense CSF and diencephalon/brainstem, as well as gray-white matter differentiation, are suboptimal.

Figure 12B. Axial T1W FLAIR image at the same levels. Robust suppression of CSF signal and improved gray-white differentiation are now evident. Symmetric high T1 signal in the bilateral pallidi is consistent with myelination.

Diagnosis：Newborn myelination.

Discussion

This case was added to illustrate the addition of inversion recovery to T1W sequences to further boost T1 contrast. Initially, inversion recovery was not used with conventional T1W SE sequences due to the excessive lengthening of the TR, which resulted in lengthy imaging times. This was overcome with the development of T1W fast inversion recovery sequences, which basically added the preparatory pulse to a T1W FSE sequence. By adding the 180° inversion pulse (converting thermal equilibrium magnetization from M0 to −M0), T1 contrast is effectively doubled.

Varying the inversion time can boost the desired contrast within the image, whether it is to improve gray-white differentiation (thus aiding in pediatric myelination staging), or to provide better delineation between tumor and surrounding edema, or to increase conspicuity of lesions bordering CSF and periventricular spaces.

While the use of an FSE sequence allowed for an acceptable imaging time, it is still three to five times longer compared to a T1W SE sequence acquiring the same number of images. Also, the FSE technique causes increased image blur, reducing imaging resolution.

Notes：

1. diencephalon /ˌdaɪen'sef(ə)lɒn/ ˌdaɪen'sef(ə)lɒn/ n. 间脑，中脑

2. suboptimal /sʌb'ɔptiməl/ /sʌb'ɔptiməl/ adj. 不是最佳的，不最适宜的

3. pallidi 苍白球

4. myelination /maiəli'nəiʃən/ /maiəli'nəiʃən/ n. 髓鞘形成

5. conspicuity /ˌkɔnspi'kju:əti/ /ˌkɑnspɪˈkjuɪti/ adj. 显著的

来源：每天朗读一段医学影像学英语文章

圈主

深圳市人民医院放射科副主任医师杨敏洁

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