MRI Study Of Normal Skull Bone Marrow Transformation In High Altitude Areas

Objective: Long-term hypoxic environment at high altitude can lead to compensatory increase in bone marrow hematopoietic erythropoiesis,so we investigated the relationship between skull marrow transformation and age,also the influence of altitude on skull marrow transformation of normal Han residents at high altitude areas using conventional MRI and DWI techniques.Methods: Select 1130 people from the altitude of 2000-3000 m,3100-4000 m and above 4000 m,the people on the same altitude will be divided into 5 age groups: 0-5,6-14,15-29,30-49,50 and above.First,according to the average thickness of normal skull barrier and signal strength,type the skull marrow of study subjects at each altitude interval on the sagittal T1WI;Then,measure the ADC values of marrow in frontal bone,parietal bone,occipital bone and temporal bone in DWI post-processing workstation;Moreover,investigate the relationship between normal skull bone marrow transformation and age as well as the influence of altitude on skull marrow transformation using statistical methods.Result:(1)For normal Han residents at each altitude interval,skull marrow type and barrier thickness of the skull were positively correlated with age(P<0.05).(2)In the age of 0~5,6~14,15~29,there was no significant statistical difference between the ADC value of skull marrow and altitude(P>0.05);In the age of 30~49,50 and above,the ADC values of the occipital and temporal marrow of normal Han residents were positively correlated with altitude(P<0.05),which had statistical significance;However,there was no significant statistical difference between the ADC value of parietal and frontal bone marrow and altitude(P>0.05).Conclusion: The skull marrow of the normal Han residents at the high altitude area changes from type I to type IV with the increase of age;The occipital and temporal marrow of residents aged above 30 has undergone bone marrow red pulp with the increase of altitude.