Bone Marrow: is it normal? Physiologic and pathologic Magnetic Resonance Imaging (MRI) findings.

Congress:

ECR 2019

Poster Number:

C-2445

Type:

Educational Exhibit

Keywords:

Neoplasia, Metastases, Normal variants, Diagnostic procedure, Decision analysis, MR, Musculoskeletal system, Musculoskeletal spine, Musculoskeletal bone

Authors:

M. G. Chiarilli, A. Delli Pizzi, M. P. Febo, B. Cardinali, B. Consorte, A. Cifaratti, A. R. Cotroneo, D. Mastrodicasa, G. Cannataro; Chieti/IT

DOI:

10.26044/ecr2019/C-2445

DOI-Link:

https://dx.doi.org/10.26044/ecr2019/C-2445

Fig. 2: Yellow marrow conversion process takes place with a characteristic sequence,...

Fig. 3: BM conversion starts in the long bones epiphyses and apophyses. It continues in...

Fig. 6: T1-relaxation time is a measure of how quickly the longitudinal magnetization...

Fig. 7: Each tissue possesses different T1 relaxation time: fat value is shorter than...

Learning objectives

Our aim is to discuss and illustrate the following objectives: Normal BM components and composition Physiologic BM conversion Normal MRI signal MRI aspect of BM variants MRI findings of BM disorders

Background

MRI is the only imaging modality allowing direct visualization of BM, whose changes interpretation can be challenging. BM MRI appearance depends on the ratio and location of yellow and red marrow. Moreover, it is known to change with age, pathologies, and treatments.

Findings and procedure details

1. Normal BM components and composition BM consists of hematopoietic stem cells, adipose cells, and stroma[1]. Normal BM is composed of both red and yellow marrow, which contains different levels of predominant components[2]. Red marrow is considered hematopoietically active. It contains a high level of hematopoietic stem cells. It is composed of 40% water, 40% fat, and 20% protein[3]. Yellow marrow is considered hematopoietically inactive. It is composed of a high number of adipocytes and low level of hematopoietic stem cells. It contains 80% fat,...

Conclusion

BM components and location in normal red/yellow and pathologic marrow are responsible for different signals in MRI sequences: it is crucial to differentiate between normal and pathologic findings. As general rule normal BM is hyperintense on T1w images as compared to muscle and intervertebral disc signals: red marrow is less hyperintense than yellow marrow. Red and yellow marrow are slightly differentiated on T2W images. On STIR red marrow is hyper-/iso-intense, yellow marrow is hypo-/iso-intense. BM variants possess normal signal intensity and symmetric distribution. BM disorders...

Personal information

References

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