脊柱变异.ppt

FNH of red marrow Diffuse hematopoietic marrow hyperplasia Presence of hypercellular hematopoietic marrow in the axial skeleton and by expansion of hematopoietic marrow in the appendicular skeleton (marrow reconversion) It occurs in response to numerous stimuli that trigger production of red marrow cells. Administration of hematopoietic growth factors during chemotherapy typically causes transient increase in marrow cellularity Several chronic disorders that are associated with anemia including hereditary hemoglobinopathies and chronic infection also cause red marrow expansion . Diffuse red marrow hyperplasia is also observed in middle-aged obese women; in heavy smokers; and in subjects with intensive sports activities, such as long-distance running. As a rule, marrow hyperplasia shows a signal similar to that of red marrow. 56Y,MM Hanrahan cj et al. Radiographics, 2010; 30:127–142 Myelofibrosis 57Y, MM 56Y,MM Summary MR imaging appearance of normal marrow shows important variations among individuals because of focal or diffuse alteration in the amount of yellow and red marrow. Nodules of hematopoietic marrow remain difficult to characterize, mainly because no single noninvasive imaging modality is able to demonstrate specific features. Diffuse red marrow hyperplasia remains a diagnostic challenge but is easily accessible to blind iliac crest biopsy, if necessary. Vertebral enostosis and hemangioma show a spectrum of changes on MR images but other imaging modalities may contribute to their characterization. THANKS! Normal Variants and Frequent Marrow Alterations thatSimulate Bone Marrow Lesions at MR Imaging Bruno C. Vande Berg B C, et al.Radiol Clin N Am 43 (2005) 761 – 770 Outline Normal appearance Normal variants Focal vertebral alterations that may simulate metastasis Siegel MJ, MRI of bone marrow,169-179 73 Y After radiation 26 Y 14M,normal bone marrow 56Y,MM Normal appearance MR imaging appearance of the vertebral marrow merely depends on the rel