Evaluation of three-dimensional arterial spin labeling perfusion imaging for the pathological investigation of musculoskeletal tumors.

The present study aimed to assess the clinical utility of three-dimensional arterial spin labeling (3D-ASL) perfusion imaging in discriminating between benign, intermediate and malignant musculoskeletal tumors, as well as to analyze the correlation between tumor blood flow (TBF) and microvessel density (MVD). 3D-ASL was performed on 44 patients with musculoskeletal tumor using a 3.0-T magnetic resonance system to obtain TBF values prior to surgery. TBF was independently measured by two radiologists. The TBF values of different groups were compared by one-way analysis of variance. A receiver operating characteristic (ROC) curve was applied to assess the threshold and diagnostic reliability of TBF. Immunohistochemical staining of tumor specimens was performed using a cluster of differentiation 34 monoclonal antibody to calculate MVD counts. The correlation between TBF and MVD counts was analyzed using correlative analysis. Pathology results for a total of 44 cases were obtained by surgery. Good interobserver agreement was found for the TBF values independently determined by the two radiologists (intra-class correlation coefficient test, 0.891; P<0.05). TBF and MVD values in the malignant group were significantly higher compared with that of the benign, and intermediate groups. No significant difference was found between the TBF and MVD values of the benign, and intermediate groups. According to the ROC analysis, the area under the curve was largest (0.951) when 45.5 ml/min/100 g was considered as the TBF cut-off value in the diagnosis. The diagnostic sensitivity and specificity were 90.5 and 100%, respectively. Additionally, a significant positive correlation was found between TBF and MVD (r, 0.784; P<0.05). The results of the present study suggest that 3D-ASL is valuable in discriminating between benign, intermediate and malignant musculoskeletal tumors. 3D-ASL may be utilized to evaluate angiogenesis in musculoskeletal tumors in vivo.