Bone Marrow Perfusion Study Based On Dynamic Contrast-enhanced Magnetic Resonance Imaging

Osteoporosis is a kind of systemic skeletal disease characterized by bone mass lostand degeneration of bone microstructure, which results in increased bone fragility andfracture. Nowadays, there are over200million of people suffering from osteoporosis,and the incidence of osteoporosis ranks6thamong all diseases over the world. Theincidence of osteoporosis is extremely high in the elderly population. The fracture andother diseases caused by osteoporosis have become a serious public health problem andnational financial burden. China is the only country with over100million of elderlypeople in the world, and the speed of elderly population growth in China is also leadingthe world. The huge elderly population and low per capita income make China facing amore severe situation than other countries in response to osteoporosis.The pathogenic mechanism of osteoporosis is still unclear now. Previous studiesreported that osteoporosis relate to gene, gender, age, race, dietary habit and otherfactors. The objective of this study is to investigate the relationship between bonemarrow blood supply and bone mineral density (BMD) by using perfusion imagingtechnology. CT perfusion imaging and MR perfusion imaging are the most commonlyused perfusion imaging technology nowadays. MR perfusion imaging includes DCE,DSC and ASL, with different weighted parameters and tracers. Pharmacokinetic modelsare used to characterize perfusion ability. Analysis of variance method (ANOVA) wasemployed to evaluate differences in pharmacokinetic parameters among groups withdifferent BMD. Kety model, Tofts model, Brix model and RR model are the mostcommonly used pharmacokinetic models in perfusion study.This study investigated the bone marrow perfusion of hip and lumbar spine bymodified Brix model, based on DCE-MRI. ANOVA and correlation analysis wereemployed to evaluate differences and correlation in perfusion parameters betweennormal subjects and osteoporosis subjects. Color mapping could provide a visualizedmeasurement for pixel-by-pixel perfusion distribution in bone marrow. The colorpercentage and perfusion parameters showed significant difference among groups withdifferent BMD. Modic changes are a common phenomenon on magnetic resonance imaging inspinal degenerative diseases and strongly linked with low back pain. There are threetypes of Modic changes called type I, II, III classified by different signal changepatterns in the MRI images. The color percentage and perfusion parameters showedsignificant difference among groups with different modic change. The study showedthat there is a link between bone perfusion, BMD and bone lesions. The change of bonemarrow blood supply could be one pathogenic mechanism of osteoporosis.