Age-related marrow conversion and developing epiphysis in the proximal femur: Evaluation with STIR MR imaging

Abstract

In order to observe the feature of age-related marrow conversion and maturation of epiphyseal cartilage and analyze the distribution of red and yellow marrow in the proximal femur at STIR MR imaging, STIR and T₁ weighted MR imaging of the proximal femur in 52 subjects, aged 4 months to 25 years old, were retrospectively analyzed for the distribution and appearance of red and yellow marrow. The subjects with no known bone marrow abnormalities were divided into 6 age groups. The signal intensity of the marrow in the proximal epiphysis, proximal metaphysis, proximal diaphysis, distal diaphysis and greater trochanter was compared with the signal intensity and homogeneity of surrounding muscle and fat and graded by two observers. The results showed that the conversion of hematopoietic marrow in the proximal femur followed a well-defined sequence, occurring first in the proximal epiphysis, followed by the distal diaphysis, and then greater trochanter and metaphysis. STIR in combination with T₁-weighted imaging could display clearly the origin of ossification center and the course of conversion from red to yellow marrow in proximal epiphysis and greater trochanter. STIR imaging showed that the marrow conversion in proximal metaphysic began below epiphyseal plate and intertrochanter. The site of red yellow was distributed in weight-bearing axis by 20 years of age. The marrow conversion of diaphysis was from distal end to proximal end, and the consequence of conversion was that distal diaphysis contained yellow marrow but proximal diaphysis partly red marrow connected with the red marrow of metaphysic. The epiphyseal cartilage had different characters of signal-intensity with age in STIR sequence. The distribution of red marrow in STIR imaging was more close to that of anatomy than T₁-weighted imaging. It was concluded that STIR could dynamically display the feature of morrow conversion and the development of epiphyseal cartilage and accurately reveal the age-related distribution of red and yellow marrow on STIR imaging in the proximal femur.

Keywords

marrow conversion / magnetic resonance imaging / fat suppression / STIR / femur

References

[1] MooreS. G., DawsonK. L.. Red and yellow marrow in the femur: age-related changes in appearance at MR imaging. Radiology, 1990, 175: 219-223

[2] WaitchesG., ZawinJ. K., PoznanskiA. K.. Sequence and rate of bone marrow conversion in the femora of children as seen on MR imaging: are accepted standrards accurate?. AJR, 1994, 162: 1399-1406

[3] AndrewsC. L.. Evaluation of the marrow space in the adult hip. Radiographics, 2000, 20: 27-42

[4] WangJ., NiuJ. L., QiJ., et al.. Marrow MRI in adult with initially diagnosed acute leukemia and clinical application. Chin Radiol J (Chinese), 2001, 6: 233-237

[5] WilpshaarJ., JoekesE.C., LimF.T., et al.. Magnetic resonance imaging of fetal bone marrow for quantitative definition of the human fetal stem cell compartment. Blood, 2002, 100: 451-457

[6] MirowitzS. A., ApicellaP., ReinusW. R., et al.. MR imaging of bone marrow lesions: relative conspicuousness on T1-weighted, fat-suppressed T2-weighted, and STIR images. AJR, 1994, 162: 215-221

[7] NaktsuM., HatabuH., ItohH., et al.. Comparison of short time inversion recovery (STIR) and fat-saturated (chemsat) techniques for gackground fat intensity suppression in cervical and thoracic MR imaging. J Magn Reson Imaging, 2000, 11: 56-60

[8] ConnollyS.A., JaramilloD., HongJ. K., et al.. Skeletal development in fetal pig specimens: MR imaging of femur with histologic comparison. Radiology, 2004, 233: 505-514

[9] KooK. H., DussaultR., KaplanP., et al.. Age-related marrow conversion in the proximal metaphysis of the femur: evaluation with T1-weighted MR imaging. Radiology, 1998, 206: 745-748

[10] RicciC., CovaM., KangY. S., et al.. Normal age-related patters of cellular and fatty bone marrow distribution in the axial skeleton: MR imaging study. Radiology, 1990, 177: 83-88

[11] VarichL. J., LaorT., JaramilloD.. Normal maturation of the distal femoral epiphyseal cartilage: Age-related changes at MR imaging. Radiology, 2000, 214: 705-709

[12] JaramilloD., ConnollyS. A., MulkernR. V., et al.. Developing epiphysis: MR imaging characteristics and histologic correlation in the newborn lamb. Radiology, 1998, 207: 637-645

[13] KellenbergerC. J., EpelmanM., MillerS. F., et al.. Fast STIR whole-body MR imaging in children. Radiographics, 2004, 24: 1317-1330