Radiation-induced MRI signal changes in bone marrow are the earliest detectable changes in bone. Their severity correlates with increasing radiation dose.
- 1st week: decreased marrow cellularity with edema and hemorrhage
- 2nd week: increased marrow cellularity due to influx from non-irradiated areas
- 1-3 months: marrow sinusoids and cellularity is decreased
- after 6 months: regeneration of hematopoietic tissue and sinusoids
Little changes in signal intensity during the first 3 weeks of radiation therapy on spin echo sequences. STIR shows increased signal intensity during this period.
After 3 weeks heterogenous mottled appearance of marrow is seen.
During 3-6 weeks marrow cellularity is replaced by central fat predominantly surrounding the basivertebral veins.
- 1. Stevens SK, Moore SG, Kaplan ID. Early and late bone-marrow changes after irradiation: MR evaluation. AJR Am J Roentgenol. 1990;154 (4): 745-50. doi:10.2214/ajr.154.4.2107669 - Pubmed citation
- 2. Mitchell MJ, Logan PM. Radiation-induced changes in bone. Radiographics. 1998;18 (5): 1125-36. doi:10.1148/radiographics.18.5.9747611 - Pubmed citation
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