TY - JOUR
T1 - Assessment of blood hemodynamics by USPIO-induced R1 changes in MRI of murine colon carcinoma
AU - Gambarota, Giulio
AU - van Laarhoven, H. W.M.
AU - Philippens, M.
AU - Peeters, W. J.M.
AU - Rijken, P.
AU - van der Kogel, A.
AU - Punt, C. J.A.
AU - Heerschap, A.
N1 - Funding Information:
Acknowledgments We thank A. Veltien and B. Lemmers for technical assistance with the MRI measurements and animal handling. We also thank J. Lok, from the Department of Radiation Oncology for providing us with the photomicrographs of tumor vasculature. This work is supported by Dutch Cancer Society, grant KUN 2000-2307 and NWO-ZONWM investment grant 902-37-088.
PY - 2010/6
Y1 - 2010/6
N2 - The objective of this study is to assess whether ultrasmall superparamagnetic iron oxide (USPIO)-induced changes of the water proton longitudinal relaxation rate (R1) provide a means to assess blood hemodynamics of tumors. Two types of murine colon tumors (C26a and C38) were investigated prior to and following administration of USPIO blood-pool contrast agent with fast R1 measurements. In a subpopulation of mice, R1 was measured following administration of hydralazine, a well-known blood hemodynamic modifier. USPIO-induced R1 increase in C38 tumors (ΔR1 = 0.072 ± 0.0081 s-1) was significantly larger than in C26a tumors (ΔR1 = 0.032 ± 0.0018 s-1, N = 9, t test, P < 0.001). This was in agreement with the immunohistochemical data that showed higher values of relative vascular area (RVA) in C38 tumors than in C26a tumors (RVA = 0.059 ± 0.015 vs. 0.020 ± 0.011; P < 0.05). Following administration of hydralazine, a decrease in R1 value was observed. This was consistent with the vasoconstriction induced by the steal effect mechanism. In conclusion, R1 changes induced by USPIO are sensitive to tumor vascular morphology and to blood hemodynamics. Thus, R1 measurements following USPIO administration can give novel insight into the effects of blood hemodynamic modifiers, non-invasively and with a high temporal resolution.
AB - The objective of this study is to assess whether ultrasmall superparamagnetic iron oxide (USPIO)-induced changes of the water proton longitudinal relaxation rate (R1) provide a means to assess blood hemodynamics of tumors. Two types of murine colon tumors (C26a and C38) were investigated prior to and following administration of USPIO blood-pool contrast agent with fast R1 measurements. In a subpopulation of mice, R1 was measured following administration of hydralazine, a well-known blood hemodynamic modifier. USPIO-induced R1 increase in C38 tumors (ΔR1 = 0.072 ± 0.0081 s-1) was significantly larger than in C26a tumors (ΔR1 = 0.032 ± 0.0018 s-1, N = 9, t test, P < 0.001). This was in agreement with the immunohistochemical data that showed higher values of relative vascular area (RVA) in C38 tumors than in C26a tumors (RVA = 0.059 ± 0.015 vs. 0.020 ± 0.011; P < 0.05). Following administration of hydralazine, a decrease in R1 value was observed. This was consistent with the vasoconstriction induced by the steal effect mechanism. In conclusion, R1 changes induced by USPIO are sensitive to tumor vascular morphology and to blood hemodynamics. Thus, R1 measurements following USPIO administration can give novel insight into the effects of blood hemodynamic modifiers, non-invasively and with a high temporal resolution.
UR - http://www.scopus.com/inward/record.url?scp=77952420858&partnerID=8YFLogxK
U2 - 10.1007/s00723-010-0124-1
DO - 10.1007/s00723-010-0124-1
M3 - Article
AN - SCOPUS:77952420858
SN - 0937-9347
VL - 38
SP - 349
EP - 360
JO - Applied Magnetic Resonance
JF - Applied Magnetic Resonance
IS - 3
ER -