INTRODUCTION AND OBJECTIVE: Recent advances in magnetic resonance (MR) technology have allowed for high-resolution ex vivo spectroscopy on small, intact tissue samples. We examined the capability of (1)H magnetic resonance magic angle spinning (MR-MAS) to correctly characterize post-radiofrequency ablation (RFA) renal biopsies from human samples, compared with standard histology and cross-sectional imaging. METHODS: A minimum of two, 18G, percutaneous renal biopsies were obtained from ten biopsy-confirmed renal tumors at a mean 26.6 mo (range, 15-48) post-RFA. All patients were considered free of disease by computed tomography criteria. A portion of each sample was immediately frozen at -80 degrees C for spectroscopy and the remainder used for pathological analysis. (1)H MR-MAS was performed blinded with a 14.1-tesla field strength. Prior renal biopsies from nonablated tissue were used as positive controls for the spectral analysis. Concordance between, computed tomography, histology, and MR-MAS was analyzed. All spectroscopy was processed with VNMR software. RESULTS: Histological analysis of all ten post-RFA biopsies demonstrated no cancer or viable tissue. All MR-MAS spectral peaks for each biopsy were consistent with necrosis and, more importantly, indicated an absence of small molecule metabolites characteristic of both normal and malignant renal tissue. Both MR-MAS and histology confirmed, in each case, the conventional computed tomography determination of complete ablation. CONCLUSIONS: MR spectroscopy can correctly diagnose the molecular absence of disease in post-RFA tissue biopsies. This proof of principle study warrants in vivo evaluation to confirm the clinical correlates of this modality.
INTRODUCTION AND OBJECTIVE: Recent advances in magnetic resonance (MR) technology have allowed for high-resolution ex vivo spectroscopy on small, intact tissue samples. We examined the capability of (1)H magnetic resonance magic angle spinning (MR-MAS) to correctly characterize post-radiofrequency ablation (RFA) renal biopsies from human samples, compared with standard histology and cross-sectional imaging. METHODS: A minimum of two, 18G, percutaneous renal biopsies were obtained from ten biopsy-confirmed renal tumors at a mean 26.6 mo (range, 15-48) post-RFA. All patients were considered free of disease by computed tomography criteria. A portion of each sample was immediately frozen at -80 degrees C for spectroscopy and the remainder used for pathological analysis. (1)H MR-MAS was performed blinded with a 14.1-tesla field strength. Prior renal biopsies from nonablated tissue were used as positive controls for the spectral analysis. Concordance between, computed tomography, histology, and MR-MAS was analyzed. All spectroscopy was processed with VNMR software. RESULTS: Histological analysis of all ten post-RFA biopsies demonstrated no cancer or viable tissue. All MR-MAS spectral peaks for each biopsy were consistent with necrosis and, more importantly, indicated an absence of small molecule metabolites characteristic of both normal and malignant renal tissue. Both MR-MAS and histology confirmed, in each case, the conventional computed tomography determination of complete ablation. CONCLUSIONS: MR spectroscopy can correctly diagnose the molecular absence of disease in post-RFA tissue biopsies. This proof of principle study warrants in vivo evaluation to confirm the clinical correlates of this modality.
Authors: Christopher Dietz; Felix Ehret; Francesco Palmas; Lindsey A Vandergrift; Yanni Jiang; Vanessa Schmitt; Vera Dufner; Piet Habbel; Johannes Nowak; Leo L Cheng Journal: NMR Biomed Date: 2017-09-15 Impact factor: 4.044
Authors: Jingfeng Jiang; Chris Brace; Anita Andreano; Ryan J DeWall; Nick Rubert; Ted G Fisher; Tomy Varghese; Fred Lee; Timothy J Hall Journal: Phys Med Biol Date: 2010-03-30 Impact factor: 3.609