Intravertebral cleft sign on fat-suppressed contrast-enhanced MR: Correlation with cement distribution pattern on percutaneous vertebroplasty

Rationale and Objectives. Filling intravertebral clefts during percutaneous vertebroplasty (PVP) is considered to be important for optimal pain control. It is often difficult to detect clefts on non-contrast MR and some fractures show a solid pattern distribution of injected cement without a cleft sign on non-contrast MR. In this study, we evaluated usefulness of fat-suppressed contrast-enhanced MR to predict a solid pattern distribution of injected cement on PVP. Materials and Methods. Twenty-six patients with 35 vertebral compression fractures due to osteoporosis were studied. We performed sagittal T1-weighted, T2-weighted and fat-suppressed contrast-enhanced T1-weighted images prior to PVP. First we evaluated the presence of fluid-filled or gas-containing clefts on non-contrast MR. Next we evaluated contrast-enhanced MR of the same vertebrae for the presence of cleft-shaped unenhanced areas within the diffuse enhancement area. We correlated MR findings with cement distribution patterns of injected cement. Results. Based on MR findings, 35 osteoporotic fractures were divided into 3 types. Type 1 (11 fractures, 31%): There were no clefts on non-contrast MR and no unenhanced areas on contrast-enhanced MR; Type 2 (13, 37%): There were no clefts on non-contrast MR but there were unenhanced areas on contrast-enhanced MR; Type 3 (13, 37%): There were clefts on non-contrast MR and unenhanced areas on contrast-enhanced MR. Of 35 osteoporotic fractures, thirteen vertebral fractures (37%) were noted to contain clefts on non-contrast MR, while 24 vertebral fractures (69%) contained unenhanced areas on contrast-enhanced MR. Cement distributed as a solid pattern within clefts or unenhanced areas in all fractures with them. Conclusion. Fat-suppressed contrast-enhanced MR is useful to predict a solid pattern distribution of injected cement prior to PVP.