MRI assessment of percutaneous ablation of liver tumors: value of subtraction images.
PURPOSE: To evaluate the value of subtraction images when using MRI to assess liver tumors treated with percutaneous ablation.
MATERIALS AND METHODS: Following percutaneous ablation of 35 liver tumors, two abdominal radiologists, blinded to outcomes, independently reviewed follow-up MRI examinations for tumoral enhancement suggestive of residual/recurrent tumor and rated their confidence level. After one year, the readers reviewed the same examinations with added subtraction images. Accuracy of the detection of residual/recurrent tumor and contrast-to-noise ratios (CNR; for tumoral enhancement-to-liver, tumoral enhancement-to-ablation zone, and ablation zone-to-liver) were calculated with and without subtraction images and compared using Wilcoxon signed rank test. Interobserver variability was computed using Kappa (κ) statistics.
RESULTS: Residual/recurrent tumor was present in 8 (23.5%) of 34 tumors. Accuracy of detecting residual/recurrent tumor with subtraction images and interobserver agreement (κ = 0.72, good) were better than accuracy of detecting residual/recurrent tumor and interobserver agreement (κ = 0.57, moderate) of enhanced MR images without subtraction. Mean CNR of subtraction images was significantly higher than that of enhanced MR images for tumoral enhancement-to-liver (0.2 ± 5 versus 11.6 ± 14.4, P = 0.03), tumoral enhancement-to-ablation zone (10.1 ± 12.5 versus 34.4 ± 29.4, P = 0.02), and ablation zone-to-liver (11.8 ± 13.3 versus 102.5 ± 238.4, P = 0.03).
CONCLUSION: When using MRI, subtraction images help both detect and exclude residual/recurrent tumor following percutaneous liver ablations.
Published In/Presented At
Tatli, S., Acar, M., Tuncali, K., Sadow, C. A., Morrison, P. R., & Silverman, S. G. (2013). MRI assessment of percutaneous ablation of liver tumors: value of subtraction images. Journal of magnetic resonance imaging : JMRI, 37(2), 407–413. https://doi.org/10.1002/jmri.23827
Diagnosis | Medicine and Health Sciences | Other Analytical, Diagnostic and Therapeutic Techniques and Equipment | Radiology
Department of Radiology and Diagnostic Medical Imaging