Résumé
Objective To investigate the changes of CT cerebral perfusion (CTP) and the application value of nuclear magnetic resonance proton spin labeling (3D-ASL) and to conduct a comparative study. Methods Multi-slice spiral CT(MDCT) was used to study the changes of CTP in 22 patients with HAPC. Comparison of CT whole-brain perfusion technique and nuclear magnetic resonance proton spin labeling technique (3D-ASL) in hemodynamic changes of the brain in plateau polycythemia. Results With the aggravation of HAPC, CBF of cerebral cortex and white matter showed a downward trend. Except the white matter of frontal lobe and temporal lobe, the difference of HAPC among different diseases was statistically significant (P < 0.05). Along with the aggravation of, each part of the brain cortex and white matter CBV increase, white matter, and each part CBV difference had statistical significance between different condition (P < 0.05). With the aggravation of the disease, the MTT of cortex and white matter in all parts of the brain increased significantly, and the difference of MTT between different parts of the disease was statistically significant (P < 0.05). HAPC patients along with the aggravation of different level, rCBF is reduced, in addition to the parietal cortex, temporal and occipital white matter, white matter rCBF differences between different parts of different condition have statistical significance (P < 0.05). ROC curve was used to evaluate the diagnostic value of CTP and ASL. The two curves were close to each other, and CTP was slightly better than ASL. Conclusion With the progression of HAPC, cerebral blood flow decreased, blood volume increased, and average blood flow time prolonged in patients with different degrees of HAPC. CTP and ASL had similar effects, and the former had slightly better value.
Résumé
Objective: This study aimed to quantitatively analyze changes in blood perfusion in brain metastases (BMs), normal brain areas, and peritumor edema areas during radiotherapy (RT) using three-dimensional arterial spin labeling (3D-ASL) in BMs patients. The associations between perfusion changes in the three brain regions and RT dose gradients need to be established to provide a reference for individualized RT for BMs patients. Methods: MR-simulated location images of 26 BMs patients before and after RT were collected (including enhanced T1W images and perfusion maps of 3D-ASL; BMs tumor target areas were identified using enhanced T1W images and perfusion information was obtained from 3D-ASL). The high signal areas of BMs on contrast-enhanced T1W images, normal brain areas, and peritumor edema areas were defined as regions of interest (ROIs). The changes and correlation of the mean maximum cross-sectional area and mean maximum cerebral blood flow (CBF) in BMs tumor target areas before and after RT were assessed. Changes in CBF values in the three ROIs under different dose gradients were analyzed. Results: The mean maximum cross-sectional area and CBF values of BMs decreased by 26.46% and 29.64%, respectively, after RT (both P50 Gy dose gradients were 33.75%, 24.61%, and 27.55%, respectively (all P50 Gy, the decreasing CBF rates after RT were 7.65%, 11.12%, 18.42%, 20.23%, 19.79%, and 17.89%, respectively (all P<0.05). The decreasing CBF rates in peritumor edema areas increased as dose gradients increased after RT. The perfusion changes in BMs after RT were more notable than those in normal brain areas and peritumor edema areas. Conclusions: Thus, 3D-ASL can objectively reflect changes in perfusion in BMs, normal brain areas, and peritumor edema areas. Based on changes in CBF, it is recommended to control the dose administered to normal brain areas to <30 Gy, whereas high doses