Proton MR spectroscopy in characterization of focal bone lesions of peripheral skeleton

Abstract

Background The aim of our study was to determine the value of single-voxel proton MR spectroscopy (1HMRS) in distinguishing benign from malignant focal bone lesions in the peripheral skeleton. MRI and 1HMRS was performed in 50 focal lesions (> 1 cm size) detected on radiographs of peripheral skeleton.1HMRS was performed at 1.5 T with TE of 144 ms with automatic shimming and water suppression. Qualitative analysis for a discrete choline peak at 3.2 ppm was done. Significance of the presence of choline peak on 1HMRS in distinguishing benign from malignant lesions was calculated using histopathology as a gold standard. Chi-square test was used and p value < 0.05 was considered significant. Results Forty-one benign and 9 malignant lesions were confirmed by histopathological results. Amongst malignant lesions, choline peak was positive in all but 1 case of low-grade lymphoma. MR spectra of 11 benign lesions showed the presence of choline peak. All 7 benign giant cell tumors (GCT) were positive for choline peak. The sensitivity, specificity, PPV, NPV of proton MR spectroscopy in differentiating benign from malignant lesions were 87.5%,71%,38.8%, and 96.4% respectively. p value was significant (< 0.05). Conclusion 1HMRS in focal bone lesions can help in the differentiation of malignant from benign musculoskeletal tumors. Although some benign lesions may show false-positive result, absence of choline peak is a reliable reassurance against malignancy. GCT is an exception amongst benign bone tumors as it consistently shows the presence of choline peak on 1HMRS.

Current progress and future trends in imaging of musculoskeletal bone tumours

“…It is unclear why a choline peak is routinely seen with GCT's; possible reasons include that most lesions included in studies are hypercellular with relatively aggressive appearing on plain radiographs. 1 GCT's with an extra osseous component in particular have a strong association with a high choline peak too, with similar ratios compared to a malignant bony lesion. 1,2 Many variables also have to be considered which can alter choline signal intensity.…”

“…1 GCT's with an extra osseous component in particular have a strong association with a high choline peak too, with similar ratios compared to a malignant bony lesion. 1,2 Many variables also have to be considered which can alter choline signal intensity. These include different coils types, magnetic field strength and size of the lesion among others.…”

“…The technique can be used to detect elevated levels of choline compounds, a marker of high cell membrane turnover commonly seen in malignant bony tumours. 1 The metabolic footprint of a lesion is based on the ratio of water, lipids and various metabolite contents with a high spectroscopic choline peak suggestive of malignancy. 2 A pooled analysis of MRS studies of de novo musculoskeletal lesions shows a strong association (p < 0.0001) between the presence of a choline peak and malignancy, with an overall sensitivity of 88% and a specificity of 68%.…”

State of the art in the diagnostic evaluation of osteomyelitis: exploring the role of advanced MRI sequences—a narrative review

“…This enables differentiation between malignant and benign lesions ( 51 , 52 ). Amar et al demonstrated that the absence of a choline peak on 1 H-MRS in focal bone lesions provides reliable assurance against malignancy (except for giant cell tumors), as illustrated in Figure 7 ( 53 ). However, using MR spectroscopy in bone lesions poses some challenges.…”