Feasibility of proton chemical shift imaging with a stereotactic headframe

To prove feasibility of proton chemical shift imaging (1H CSI) during stereotactic procedure, authors performed 1H CSI in combination with a stereotactic headframe and selected targets according to local metabolic information, evaluated the pathologic results. The 1H CSI directed stereotactic biopsy was performed in four patients. 1H CSI and conventional Gd-enhancement stereotactic MRI were performed simultaneously after the fitting of a stereotactic headframe. Focal areas of increased phosphocholine(Cho)/phosphocreatine(Cr) and Lactate/Cr ratios were selected as target sites in the stereotactic MR images. 1H CSI is possible with the stereotactic headframe in place. Pathologic samples taken from areas of increased Cho/Cr ratios and decreased NAA/Cr ratios provided information upon increased cellularity, mitoses and cellular atypism, and facilitated diagnosis. Pathologic samples taken from areas of increased Lac/Cr ratio showed predominant feature of necrosis. 1H CSI was feasible with the stereotactic headframe in place. The final pathologic results obtained were concordant with the local metabolic information from 1H CSI. We believe that 1H CSI-directed stereotactic biopsy has the potential to significantly improve the accuracy of stereotactic biopsy targeting.