Premium
The effect of flow on blood oxygen level dependent (R * 2 ) MRI of orthotopic lung tumors
Author(s) -
Zhou Heling,
Belzile Olivier,
Zhang Zhang,
Wagner Jo,
Ahn Chul,
Richardson James A.,
Saha Debabrata,
Brekken Rolf A.,
Mason Ralph P.
Publication year - 2019
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.27661
Subject(s) - blood flow , oxygenation , nuclear medicine , lung , voxel , nuclear magnetic resonance , magnetic resonance imaging , chemistry , breathing , intensity (physics) , lung cancer , medicine , pathology , physics , radiology , anatomy , quantum mechanics
Purpose Blood oxygen level dependent (BOLD) MRI based onR 2 * measurements can provide insights into tumor vascular oxygenation. However, measurements are susceptible to blood flow, which may vary accompanying a hyperoxic gas challenge. We investigated flow sensitivity by comparingR 2 * measurements with and without flow suppression (fs) in 2 orthotopic lung xenograft tumor models. Methods H460 (n = 20) and A549 (n = 20) human lung tumor xenografts were induced by surgical implantation of cancer cells in the right lung of nude rats. MRI was performed at 4.7T after tumors reached 5 to 8 mm in diameter. A multiecho gradient echo MRI sequence was acquired with and without spatial saturation bands on each side of the imaging plane to evaluate the effect of flow onR 2 * . fs and non‐fsR 2 * MRI measurements were interleaved during an oxygen breathing challenge (from air to 100% O 2 ).T 2 * ‐weighted signal intensity changes (ΔSI(%)) andR 2 * measurements were obtained for regions of interest and on a voxel‐by‐voxel basis and discrepancies quantified with Bland–Altman analysis. Results Flow suppression affected ΔSI(%) andR 2 * measurements in each tumor model. Average discrepancy and limits of agreement from Bland–Altman analyses revealed greater flow‐related bias in A549 than H460. Conclusion The effect of flow onR 2 * , and hence BOLD, was tumor model dependent with measurements being more sensitive in well‐perfused A549 tumors.