Chemical shift magnetic resonance imaging in differentiation of benign from malignant vertebral collapse in a rural tertiary care hospital in North India

The importance of bone marrow infiltration patterns in multiple myeloma seen on magnetic resonance imaging-Case report and imaging perspective

Non-secretory multiple myeloma (NSMM) is an extremely rare variant of multiple myeloma (MM) and accounts for a maximum of 5% of all myeloma cases. This variant of MM usually represents a diagnostic challenge to the clinician because of the absence of detectable monoclonal immunoglobulin on serum or urine electrophoresis. We present the case of a 34-year-old Caucasian male who presented to the emergency department with pain in the lumbar area secondary to a fall and who was eventually diagnosed with non-secretory multiple myeloma after the radiologist initially pointed out a discrete "salt and pepper" infiltration of the spine seen on magnetic resonance imaging (MRI) although the spine computed tomography (CT) performed initially showed no suspicious lesions for malignancy. The final diagnosis was obtained after a positive bone marrow biopsy together with the presence of malignant lesions seen on the spine MRI. This case points out the importance of different bone marrow involvement patterns seen on MRI and other useful sequences the radiologist could use to better discriminate between normal marrow reconversion and malignant infiltration.

FDG-PET vs. chemical shift MR imaging in differentiating intertrabecular metastasis from hematopoietic bone marrow hyperplasia

Purpose

To evaluate the utility of SUVmax on FDG-PET and chemical shift imaging (CSI) on MRI in the differentiation of intertrabecular metastasis (ITM) from hematopoietic bone marrow hyperplasia (HBMH).

Patients and methods

We retrospectively evaluated 54 indeterminate focal bone marrow lesions in 44 patients detected on FDG-PET. The lesions were assigned to the metastasis group (M group, 29 lesions of 24 patients) and the non-metastasis group (non-M group, 25 lesions of 20 patients) based on the follow-up or the histopathological studies. The lesions were assessed with the maximum standardized uptake value (SUV_max) on FDG-PET CT images and signal change ratio (SCR) on CSI.

Results

The median SUV_max were 5.62 and 2.91; the median SCR were − 0.08 and − 34.8 in M and non-M groups respectively, with significant difference (p < 0.001). With ROC curve analysis, the optimal cutoff value of SUV_max was 4.48 with a sensitivity of 72.4%, a specificity of 100%, and AUC of 0.905. The cutoff value of SCR was − 6.15 with a sensitivity of 82.8%, a specificity of 80%, and AUC of 0.818.

Conclusion

FDG-PET and CSI on MRI are useful in distinguishing ITM from HBMH. Though their sensitivities are similar, the specificity of FDG-PET was higher than that of MRI.