Differential diagnosis of benign and malignant vertebral compression fractures using conventional and advanced MRI techniques

Abstract

Atraumatic vertebral compression fractures (VCFs) are commonly encountered in clinical practice and often represent a diagnostic challenge. MRI plays a major role in the differential diagnosis of benign and malignant VCFs, due to its high contrast resolution and the possibility to obtain quantitative and functional data with the employment of advanced sequences. Computer-aided diagnosis systems are also applied on MRI images for this purpose, showing promising results. In this setting, aim of this pictorial review is to elucidate the role of MRI in the differential diagnosis of VCFs with a specific focus on advanced and post-processing imaging techniques.

Imaging of Bone Marrow: From Science to Practice

“…In the case of VFs, recent studies were successful in demonstrating that, although not providing clear differentiation, some semiquantitative parameters were significantly diverse between pathologic and osteoporotic VFs. 51,54,59 True quantitative DCE-MRI perfusion parameters were superior to semiquantitative parameters and significantly different between osteoporotic and malignant VFs, and therefore they may be used as an indicator to distinguish between them, especially in the acute setting. Interestingly, the technique was suggested as a tool to predict the progression of collapse of VFs, from results showing an increased tendency of progression of collapse with increased unenhanced areas.…”

“…Six-echo Dixon MRI sequences showed a good diagnostic accuracy of fat fraction and fat fraction ratio in the case of VFs, with AUC values of 0.98 and 0.95, respectively. 51 54…”

“…For this reason, some authors recently advocated increasing the percentage of signal drop-off from 20% to 35% as a threshold value, to increase confidence that a fracture is malignant in origin. [50][51][52] Using this threshold, the positive predictive value was 100%; the negative predictive value was 95%. False positives exist, for example in the presence of sclerosis or fibrosis of the marrow or hemorrhage.…”

“…Six-echo Dixon MRI sequences showed a good diagnostic accuracy of fat fraction and fat fraction ratio in the case of VFs, with AUC values of 0.98 and 0.95, respectively. 51,54 Some sclerotic lesions, such as when there is myelofibrosis and in cases of healing fractures, demonstrate signal increase in out-of-phase imaging. Similarly, sclerotic fatcontaining marrow lesions, such as atypical hemangiomas and in Paget's disease, may produce insufficient marrow signal decrease to allow differentiation from infiltrative lesion.…”

Role of Magnetic Resonance In-Phase and Out of Phase Sequences in Differentiating Benign from Suspicious Vertebral Marrow Lesion

“…In an effort to differentiate between benign and malignant disease, morphologic criteria as well as diffusion imaging has been used. Because benign vertebral fractures should contain fatty marrow and malignant processes replace normal marrow, differentiation of these 2 processes should be possible with in-phase/opposed-phase imaging [3] .…”