Limits...
High temporal resolution parametric MRI monitoring of the initial ischemia/reperfusion phase in experimental acute kidney injury.

Pohlmann A, Hentschel J, Fechner M, Hoff U, Bubalo G, Arakelyan K, Cantow K, Seeliger E, Flemming B, Waiczies H, Waiczies S, Schunck WH, Dragun D, Niendorf T - PLoS ONE (2013)

Bottom Line: There is an unmet need to better understand the mechanisms operative during the initial phase of ischemic AKI.Our study demonstrated for the first time that continuous and high temporal resolution parametric MRI is feasible for in-vivo monitoring and characterization of I/R induced AKI in rats.This technique may help in the identification of the timeline of key events responsible for development of renal damage in hypoperfusion-induced AKI.

View Article: PubMed Central - PubMed

Affiliation: Berlin Ultrahigh Field Facility, Max Delbrück Center for Molecular Medicine, Berlin, Germany. andreas.pohlmann@mdc-berlin.de

ABSTRACT
Ischemia/reperfusion (I/R) injury, a consequence of kidney hypoperfusion or temporary interruption of blood flow is a common cause of acute kidney injury (AKI). There is an unmet need to better understand the mechanisms operative during the initial phase of ischemic AKI. Non-invasive in vivo parametric magnetic resonance imaging (MRI) may elucidate spatio-temporal pathophysiological changes in the kidney by monitoring the MR relaxation parameters T2* and T2, which are known to be sensitive to blood oxygenation. The aim of our study was to establish the technical feasibility of fast continuous T2*/T2 mapping throughout renal I/R. MRI was combined with a remotely controlled I/R model and a segmentation model based semi-automated quantitative analysis. This technique enabled the detailed assessment of in vivo changes in all kidney regions during ischemia and early reperfusion. Significant changes in T2* and T2 were observed shortly after induction of renal ischemia and during the initial reperfusion phase. Our study demonstrated for the first time that continuous and high temporal resolution parametric MRI is feasible for in-vivo monitoring and characterization of I/R induced AKI in rats. This technique may help in the identification of the timeline of key events responsible for development of renal damage in hypoperfusion-induced AKI.

Show MeSH

Related in: MedlinePlus

Synopsis of the hypoxia/hyperoxia and ischemia/reperfusion results.Mean changes ΔT2* (a), ΔT2 (b), ΔR2* (c) and ΔR2 (d) in percent of baseline for all regions-of-interest in the cortex (C1, C2, C3; blue), in the outer medulla (O1, O2, O3; red) and inner medulla (I1, I2, I2; green). Shown are the values for end-hypoxia, end-hyperoxia, end-ischemia and end-reperfusion.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3585384&req=5

pone-0057411-g007: Synopsis of the hypoxia/hyperoxia and ischemia/reperfusion results.Mean changes ΔT2* (a), ΔT2 (b), ΔR2* (c) and ΔR2 (d) in percent of baseline for all regions-of-interest in the cortex (C1, C2, C3; blue), in the outer medulla (O1, O2, O3; red) and inner medulla (I1, I2, I2; green). Shown are the values for end-hypoxia, end-hyperoxia, end-ischemia and end-reperfusion.

Mentions: For a quantitative synopsis of the ischemia-reperfusion results together with the hypoxia/hyperoxia results the MR parameter values at baseline, end-hypoxia/hyperoxia, end-ischemia and end-reperfusion were chosen. The group mean T2* and T2 with standard errors (SEM) are surveyed for all regions-of-interest in Table S1, together with the corresponding relativities R2* and R2. Relative changes in these parameters are summarized in Figure 7. ΔT2* (ΔR2*) and ΔT2 (ΔR2) derived from the outer/inner medulla exceeded those observed in the cortex (except for ΔT2 (ΔR2) during reperfusion). For all regions the T2* (R2*) changes during ischemia were more pronounced than during hypoxia. T2 (R2) effects during ischemia were comparable to hypoxia.


High temporal resolution parametric MRI monitoring of the initial ischemia/reperfusion phase in experimental acute kidney injury.

Pohlmann A, Hentschel J, Fechner M, Hoff U, Bubalo G, Arakelyan K, Cantow K, Seeliger E, Flemming B, Waiczies H, Waiczies S, Schunck WH, Dragun D, Niendorf T - PLoS ONE (2013)

Synopsis of the hypoxia/hyperoxia and ischemia/reperfusion results.Mean changes ΔT2* (a), ΔT2 (b), ΔR2* (c) and ΔR2 (d) in percent of baseline for all regions-of-interest in the cortex (C1, C2, C3; blue), in the outer medulla (O1, O2, O3; red) and inner medulla (I1, I2, I2; green). Shown are the values for end-hypoxia, end-hyperoxia, end-ischemia and end-reperfusion.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3585384&req=5

pone-0057411-g007: Synopsis of the hypoxia/hyperoxia and ischemia/reperfusion results.Mean changes ΔT2* (a), ΔT2 (b), ΔR2* (c) and ΔR2 (d) in percent of baseline for all regions-of-interest in the cortex (C1, C2, C3; blue), in the outer medulla (O1, O2, O3; red) and inner medulla (I1, I2, I2; green). Shown are the values for end-hypoxia, end-hyperoxia, end-ischemia and end-reperfusion.
Mentions: For a quantitative synopsis of the ischemia-reperfusion results together with the hypoxia/hyperoxia results the MR parameter values at baseline, end-hypoxia/hyperoxia, end-ischemia and end-reperfusion were chosen. The group mean T2* and T2 with standard errors (SEM) are surveyed for all regions-of-interest in Table S1, together with the corresponding relativities R2* and R2. Relative changes in these parameters are summarized in Figure 7. ΔT2* (ΔR2*) and ΔT2 (ΔR2) derived from the outer/inner medulla exceeded those observed in the cortex (except for ΔT2 (ΔR2) during reperfusion). For all regions the T2* (R2*) changes during ischemia were more pronounced than during hypoxia. T2 (R2) effects during ischemia were comparable to hypoxia.

Bottom Line: There is an unmet need to better understand the mechanisms operative during the initial phase of ischemic AKI.Our study demonstrated for the first time that continuous and high temporal resolution parametric MRI is feasible for in-vivo monitoring and characterization of I/R induced AKI in rats.This technique may help in the identification of the timeline of key events responsible for development of renal damage in hypoperfusion-induced AKI.

View Article: PubMed Central - PubMed

Affiliation: Berlin Ultrahigh Field Facility, Max Delbrück Center for Molecular Medicine, Berlin, Germany. andreas.pohlmann@mdc-berlin.de

ABSTRACT
Ischemia/reperfusion (I/R) injury, a consequence of kidney hypoperfusion or temporary interruption of blood flow is a common cause of acute kidney injury (AKI). There is an unmet need to better understand the mechanisms operative during the initial phase of ischemic AKI. Non-invasive in vivo parametric magnetic resonance imaging (MRI) may elucidate spatio-temporal pathophysiological changes in the kidney by monitoring the MR relaxation parameters T2* and T2, which are known to be sensitive to blood oxygenation. The aim of our study was to establish the technical feasibility of fast continuous T2*/T2 mapping throughout renal I/R. MRI was combined with a remotely controlled I/R model and a segmentation model based semi-automated quantitative analysis. This technique enabled the detailed assessment of in vivo changes in all kidney regions during ischemia and early reperfusion. Significant changes in T2* and T2 were observed shortly after induction of renal ischemia and during the initial reperfusion phase. Our study demonstrated for the first time that continuous and high temporal resolution parametric MRI is feasible for in-vivo monitoring and characterization of I/R induced AKI in rats. This technique may help in the identification of the timeline of key events responsible for development of renal damage in hypoperfusion-induced AKI.

Show MeSH
Related in: MedlinePlus