Characterization of hematopoietic bone marrow in male professional cyclists by magnetic resonance imaging of the lumbar spine

Abstract

Purpose: To prospectively evaluate hematopoietic bone marrow of male professional cyclists in relation to performance data and laboratory data, and in comparison to age-matched healthy volunteers. Materials and Methods:Twenty male cyclists and 44 volunteers (27 males and 17 females) were prospectively studied by magnetic resonance imaging (MRI) at high-field strength. A sagittal T1-weighted (T1-w) spin-echo (SE) sequence, a gradient-echo (GE) sequence with an echo time (TE) for out-of-phase (OOP) imaging, and a turbo inversionrecovery sequence with short inversion time (TIRM) for fat suppression was used. The averaged bone marrow signal intensity (SI) of three adjacent vertebrae was related to the signal of an adjacent nondegenerative disk. Results:The cyclists revealed a significantly different SI as compared to male volunteers in the OOP (0.34 Ϯ 0.14 vs. 0.28 Ϯ 0.09, P Ͻ 0.05) and T1-w sequences (1.62 Ϯ 0.19 vs. 1.77 Ϯ 0.30, P Ͻ 0.05). Only in TIRM was there a significant difference compared to female volunteers (0.36 Ϯ 0.08 vs. 0.44 Ϯ 0.04, P Ͻ 0.01). MRI data of cyclists did not correlate to hemoglobin, erythrocyte, or reticulocyte counts; ferritin, relative heart volume, relative maximal power (rPmax; W/kg bw), or relative maximal oxygen consumption (VO 2 max). A borderline linear correlation was found for hematocrit (OOP: r ϭ 0.42, P ϭ 0.06; TIRM: r ϭ 0.44, P ϭ 0.06). Conclusion:Bone marrow hyperplasia is observed in male professional cyclists in the axial skeleton. The MR findings are probably independent of mechanically induced marrow edema. A multifactorial cause must be considered, as single laboratory and performance data did not appear to contribute significantly to these results.

Quantitative and Semiquantitative Evaluation of Erythropoietin-Induced Bone Marrow Signal Changes in Lumbar Spine MRI in Patients with Tumor Anemia

“…Leukemia, multiple myeloma, and marrow infiltration in patients with carcinoma are diseases that cause an increase in the cell count of the hematopoietic bone marrow [1][2][3][4]. Similar observations have been reported after application of hematopoietic growth factors like recombinant human granulocyte colony stimulating factor (rHuG-CSF) or recombinant hematopoietic growth factor erythropoietin (rHuEpo) described in our study [5,6].…”

“…In opposed-phase gradient-echo sequences which are very sensitive to changes in the fat-water ratio, the signal also increases [8]. The underlying process of a relative increase in the water fraction in relation to the fatty component is similar in hematological diseases and stimulated hematopoiesis caused for example by epoietin [1,4]. To our knowledge, there is no published data stating that anemia might cause signal alterations in the bone marrow [9].…”

“…Hence, MRI is a very sensitive method to detect bone marrow signal changes which are characterized by signal decrease in T1-w SE and corresponding augmentation in OPP and Turbo-STIR ( fig. 3a-c) [1,2,4,7,[23][24][25][26][27][28][29].…”

“…Care was also taken to avoid signal loss within the ROI of the nucleus pulposus, which was considered a reference by avoiding inclusion of the annulus fibrosus. An adjacent non-degenerative disc was present in all patients and used for measurement [1,2]. We looked for differences between the epoietin and placebo group at each of the 3 measurement using the quantitatively assessed data.…”

Effects of Exercise Training on Red Blood Cell Production: Implications for Anemia

“…MRI of the bone is an accurate, noninvasive imaging modality for characterizing physiological conditions of the bone marrow. Alterations in the hematopoietic bone marrow suggestive of stimulated hematopoiesis have been observed in endurance athletes by means of MRI [48,49,50,51], and the stimulated erythropoiesis with hyperplasia of the hematopoietic bone marrow in endurance athletes could explain their large red cell volume [51]. …”