Combining morphological and functional imaging parameters to diagnose primary bone neoplasms in the skull base, spine and sacrum

Abstract

Purpose Morphological magnetic resonance (MR) and computed tomography (CT) features are used in combination with histology for diagnosis and treatment selection of primary bone neoplasms. Isolated functional MRI parameters have shown potential in diagnosis. Our goal is to facilitate diagnosis of primary bone neoplasms of the skull base, mobile spine and sacrum, by a comprehensive approach, combining morphological and functional imaging parameters. Materials and methods Pre-treatment MR of 80 patients with histologically proven diagnosis of a primary bone neoplasm of the skull base, mobile spine and sacrum were retrospectively analyzed for morphological and functional MRI parameters. Functional parameters were measured in 4 circular regions of interest per tumor placed on non-adjacent scan slices. Diferences in values of functional parameters between diferent histologies were analyzed with Dunn’s test. Results Chordomas were the predominant histology (60.0%). Most neoplasms (80.0%) originated in the midline and had geographical (78.2%) bone destruction. Amorphous-type calcifcation (pre-existing bone) was seen only in chordomas. Homogeneous contrast enhancement pattern was seen only in chondrosarcoma and plasmacytoma. Ktrans and Kep were signifcantly lower in both chordoma, and chondrosarcoma compared to giant cell tumor of the bone (p=0.006 – 0.011), and plasmacytoma (p=0.004 – 0.014). Highest difusion-weighted MRI apparent difusion coefcient (ADC) values corresponded to chondrosarcoma and were signifcantly higher to those of chordoma (p=0.008). Conclusion We identifed the most discriminating morphological parameters and added functional MR parameters based on histopathological features that are useful in making a confdent diagnosis of primary bone neoplasms in the skull base, mobile spine and sacrum