Objective:To assess the change rules of fetal cervical, thoracic and lumbar spinal volume and centrum volume with gestational ages.Methods:The 3.0 T MRI was performed on 55 fetal specimens ranging from 17 to 42 gestational weeks with sequence of three dimensional T 2WI. Among 55 samples, 20 samples were obtained from spontaneous abortion of pregnant women and 35 samples were obtained from induced labor of mothers due to serious diseases. The fetal specimen was derived from sectional imaging anatomy research institute of the medical school of Shandong University. No spinal abnormalities were found on CT scans. The cervical, thoracic and lumbar spinal volume was obtained by delineating the vertebral body contour on the reconstructed cross-sectional image with the OsiriX software (www.osirix-viewer.com). And the volume of the cervical, thoracic and lumbar spine was divided by the number of the vertebral bodies to obtain the centrum unit volume. Five lumbar vertebral bodies were measured one by one. Regression analysis was made between the volume of cervical, thoracic and lumbar spine and gestational weeks, and between the volume of lumbar vertebral bodies and gestational weeks to analyze the growth rule of spine. Results:(1) The cervical, thoracic and lumbar spine volume increased linearly with gestational ages, and the linear regression equation was as follows: cervical spine volume (mm 3) =-1 260.937+81.235×gestational week ( R2=0.974, P<0.05), thoracic spine volume (mm 3) =-5 933.521+347.503×gestational week ( R2=0.972, P<0.05), lumbar spine volume (mm 3) =-5 130.912+294.473×gestational week ( R2=0.976, P<0.05). (2) The order from large to small of fetal spinal growth rate was thoracic, lumbar and cervical segment. Within the same gestational age, the order from large to small of spinal volume was thoracic, lumbar and cervical segment. The order from large to small of centrum unit volume growth rate was lumbar, thoracic and cervical vertebrae. (3) The volume of each lumbar vertebral body also increased linearly with gestational age. Conclusion:The cervical, thoracic and lumbar volume show a good correlation with the gestational weeks in the second and third trimester fatal specimens, and the growth rate of different segments is different.

Objective To evaluate the predictive value of T2-fluid attenuated inversion recovery (FLAIR)signal suppression rate for the short arm of chromosome 1 and long arm of chromosome 19 (1p/19q)molecular features in lower-grade gliomas (LGG),and to construct and verify the predictive model based on magnetic resonance imaging (MRI)tumor features and T2-FLAIR signal suppression rate.Methods Clincal and imaging data of the patients with pathologically confirmed supratentorial LGG (WHO grade 2～3)in our medical center from 2017 to 2021 were collected and retrospectively analyzed.According to the results of postoperative molecular pathology,they were divided into 1 p/19q-codeleted (1 p/19q-Codel)and 1 p/19q-noncodeleted (1 p/19q-Noncodel)groups.MRI tumor features were blindly assessed by 2 neuroradiologists.Five circular regions of interest were respectively delineated in the tumor area and the normal-appearing white matter in contralateral semioval center using the hot-spot method in order to calculate the T2-FLAIR signal suppression rate.The differences of clinical features,MRI tumor features and T2-FLAIR signal suppression rate were analyzed between the 2 groups.Univariate and multivariate logistic regression analyses were used to screen independent predictors and constructa predictive model and nomogram.Receiver operating characteristic (ROC)curve,calibration curve and Hosmer-Lemeshow test were applied to assess the model performance,and the model was internally validated by bootstrap method.Results A total of 146 supratentorial LGG patients were enrolled,including 68 being assigned into the 1 p/19q-Codel group and 78 into the 1 p/19q-Noncodel group.The T2-FLAIR signal suppression rate was 0.43 (0.28,0.62)in the 1 p/19q-Noncodel group,which was significantly higher than that in the 1 p/19q-Codel group[0.29 (0.24,0.35),P<0.001].Multivariate logistic regression analysis showed that T2-FLAIR signal suppression rate>0.374 (P<0.001),cortex infiltration (P=0.001) and calcification (P=0.004) were independent predictors for 1 p/19q status.The AUC value of T2-FLAIR signal suppression rate>0.374 in predicting 1 p/19q-Noncodel was 0.720,the sensitivity was 60.26％ and the specificity was 83.82％.DeLong test indicated that T2-FLAIR signal suppression rate>0.374 was more effective than T2-FLAIR mismatch sign in predicting 1 p/19q molecular features (P<0.001).ROC curve analysis suggested that the predictive model established by T2-FLAIR signal suppression rate>0.374 combined with cortex infiltration and calcification had good performance,with an AUC value of 0.808,and the AUC value verified internally by bootstrap method was 0.807.At the same time,the calibration and goodness of fit of the model were good.Conclusion T2-FLAIR signal suppression rate can be used as a quantitative imaging marker to predict 1 p/19q-Noncodel LGG.The predictive model with T2-FLAIR signal suppression rate>0.374 combined with cortex infiltration and calcification can effectively predict 1 p/19q molecular features.