Normal Fatty Marrow Variants


KEY FACTS

Terminology

  • Red marrow: Hematopoietic marrow

  • Yellow marrow: Fatty marrow

Imaging

  • Yellow marrow often distributed around central perforating vein

  • Yellow marrow adjacent to endplates in degenerative disc disease

  • After bone marrow transplantation: Fat centrally located in vertebral body, red marrow at periphery

    • Yellow marrow high T1W signal intensity

    • Red marrow low to intermediate T1W signal intensity

  • Signal intensity equal or slightly higher than muscle

Top Differential Diagnoses

  • Leukemia

  • Multiple myeloma

  • Metastasis

  • Myelofibrosis

  • Hemangioma

Pathology

  • Normal marrow pattern changes with age

  • Primarily erythropoietic marrow in childhood

  • Gradually converts to fatty marrow during adulthood

  • Fatty marrow 1st seen around central draining vein

  • Fatty, erythropoietic marrow often intermixed in marbled pattern

  • Converts to predominantly fatty marrow in later adulthood

  • Red marrow reconversion occurs with anemia, obesity, high athletic activity, bone marrow transplantation, and erythropoietic stimulating agents

Clinical Issues

  • Asymptomatic

Diagnostic Checklist

  • Marrow fat patterns vary with age, health

Sagittal T2WI MR in a 15-year-old patient shows fat
centered on the draining vein
at each vertebral level. The remainder of the vertebral body contains red marrow, the usual pattern in young patients.

Sagittal T1WI MR in a 50-year-old patient shows a polka dot appearance of yellow and red marrow. Fat tends to be centered around the draining veins and adjacent to degenerated discs
. Red marrow is of equal or slightly higher signal intensity compared with muscle
.

Sagittal T1WI MR in an 85-year-old patient shows that marrow is predominantly fatty, but small foci of erythropoietic marrow
, appearing as subtle hypointense areas, are still present interspersed throughout. Although red marrow involutes with aging, there is always some red marrow in the spine, unless a patient has been treated with radiation therapy.

Sagittal T1WI MR shows a difference in signal intensity between normal fatty marrow
, irradiated marrow
, and tumor infiltration
.

TERMINOLOGY

Definitions

  • Red marrow: Hematopoietic marrow

  • Yellow marrow: Fatty marrow

IMAGING

You're Reading a Preview

Become a Clinical Tree membership for Full access and enjoy Unlimited articles

Become membership

If you are a member. Log in here