Preliminary Assessment of Turbo Spectroscopic Imaging for Targeting in Brain Biopsy

• Published in: American journal of neuroradiology : AJNR 2001-05, Vol.22 (5), p.959-968
• Main Authors: Martin, Alastair J, Liu, Haiying, Hall, Walter A, Truwit, Charles L
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aged; Biological and medical sciences; Biopsy - methods; Brain; Brain - metabolism; Brain - pathology; Brain Neoplasms - diagnosis; Brain Neoplasms - metabolism; Choline - metabolism; Female; Humans; Investigative techniques, diagnostic techniques (general aspects); Magnetic Resonance Imaging; Male; Medical sciences; Middle Aged; Nervous system; Radiodiagnosis. Nmr imagery. Nmr spectrometry; Spectrum Analysis - methods
• ISSN: 0195-6108; 1936-959X

Brain biopsy remains an integral and necessary component in the diagnosis of brain lesions. We assessed the ability of turbo spectroscopic imaging (TSI) to provide a physiologically based target for tissue sampling. TSI was performed in 26 anesthetized patients immediately before MR-guided brain biopsy. In 10 patients, single-voxel spectroscopy was performed on the TSI-indicated target and correlated with the TSI findings. Biopsy samples were taken from the imaging and spectroscopically defined target(s) under MR guidance, and pathologic findings were compared with preoperative spectra. TSI alone provided a definitive target based on a region of elevated choline in 17 of 21 patients in whom a neoplasm was confirmed. The remaining four neoplasms exhibited relatively low metabolic levels and were difficult to distinguish from the five cases of radiation necrosis seen in this study. TSI findings were in qualitative agreement with those obtained at single-voxel spectroscopy, although TSI spectra exhibited more contamination. Quantitative spectral analysis of TSI data is limited by low spectral resolution. TSI is helpful for determining an appropriate biopsy target in heterogeneous lesions. Coupling TSI targeting with conventional imaging and intraoperative confirmation of needle positioning resulted in a 100% diagnostic success rate and increased the clinician's confidence in the histologic findings.