Advanced

AJNR - American Journal of Neuroradiology

Published ahead of print on November 20, 2008
doi: 10.3174/ajnr.A1362

This Article Free to Access Abstract Full Text Full Text (PDF) Supplemental Online Table Alert me when this article is cited Alert me if a correction is posted Citation Map Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Barajas, R.F. Articles by Cha, S. Search for Related Content PubMed PubMed Citation Articles by Barajas, R.F. Articles by Cha, S.

Distinguishing Recurrent Intra-Axial Metastatic Tumor from Radiation Necrosis Following Gamma Knife Radiosurgery Using Dynamic Susceptibility-Weighted Contrast-Enhanced Perfusion MR Imaging

R.F. Barajas^a, J.S. Chang^a, P.K. Sneed^b, M.R. Segal^c, M.W. McDermott^d and S. Cha^a,d

^a Department of Radiology, Neuroradiology Section; University of California, San Francisco, San Francisco, Calif
^b Department of Oncology; University of California, San Francisco, San Francisco, Calif
^c Departments of Epidemiology and Biostatistics; University of California, San Francisco, San Francisco, Calif
^d Department of Neurological Surgery; University of California, San Francisco, San Francisco, Calif

View larger version (31K): [in this window] [in a new window]   Fig 1. Perfusion examination No. 7. A 54-year-old woman with a history of recurrent metastatic non-small cell lung cancer 7.7 months after gamma knife radiosurgery. A and B, Contrast-enhanced SPGR T1-weighted image (A) and CBV map (B) with a single region of interest surrounding the entire contrast-enhancing region demonstrate an enhancing region with corresponding elevated CBV within the right posterior frontal and parietal lobes. C, Representative T2* signal-intensity time curve obtained from a single region of interest demonstrates PH represented as A (So – Smin) and PSR calculated as B / A (S1 – Smin/So – Smin).

View larger version (42K): [in this window] [in a new window]   Fig 2. Transverse contrast-enhanced SPGR T1-weighted images (left) and T2* relaxivity-derived signal-intensity time curves (right) in histologically proved recurrent metastatic intra-axial adenocarcinoma of the lung (A) and radiation necrosis (B) show a significant difference in rCBV, rPH, and PSR. A, Perfusion MR imaging No. 16. Left occipital enhancing lesion in a 69-year-old man 17.9 months after metastatic tumor resection and gamma knife radiosurgery. A single region of interest surrounding the enhancing region (top) and a region of interest overlying the NAWM and enhancing region (bottom) demonstrate markedly elevated rCBV and rPH associated with 55% PSR. B, Perfusion MR imaging No. 31. A 66-year-old man with a left occipital enhancing lesion histologically proved to be due to radiation necrosis 4.3 months after gamma knife radiosurgery. A single region of interest surrounding the enhancing region (top) and a region of interest overlying NAWM and the enhancing region (bottom) demonstrate slightly decreased rCBV and rPH associated with 84% PSR. Considerable heterogeneity in the shape of the dynamic concentration time curves is noted throughout the contrast-enhancing lesion in both patients.