Analysing the response in R2* relaxation rate of intracranial tumours to hyperoxic and hypercapnic respiratory challenges: initial results

Müller, Andreas; Remmele, Stefanie; Wenningmann, Ingobert; Clusmann, Hans; Träber, Frank; Flacke, Sebastian; König, R.; Gieseke, Jürgen; Willinek, Winfried A.; Schild, Hans H.; Mürtz, Petra

doi:10.1007/s00330-010-1948-7

Cited by 14 publications

(10 citation statements)

References 49 publications

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“…The high temporal resolution of the approach enables the detection of differences in the kinetics of tumors and normal tissue. In previous measurements with similar protocols (31, 39, 40) very stable and reproducible response curves in healthy young volunteers were acquired. In contrary, the stability and amplitude of the response curves assessed in this study varied between the volunteer and patients, and between the affected and nonaffected hemisphere in patients with intracranial tumors.…”

Section: Discussionmentioning

confidence: 99%

Dynamic and simultaneous MR measurement of R₁ and R₂* changes during respiratory challenges for the assessment of blood and tissue oxygenation

Remmele

Sprinkart

Müller

et al. 2012

Magnetic Resonance in Med

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This work presents a novel method for the rapid and simultaneous measurement of R1 and R2* relaxation rates. It is based on a dynamic short repetition time steady-state spoiled multigradient-echo sequence and baseline R1 and B1 measurements. The accuracy of the approach was evaluated in simulations and a phantom experiment. The sensitivity and specificity of the method were demonstrated in one volunteer and in four patients with intracranial tumors during carbogen inhalation. We utilized (ΔR2*, ΔR1) scatter plots to analyze the multiparametric response amplitude of each voxel within an area of interest. In normal tissue R2* decreased and R1 increased moderately in response to the elevated blood and tissue oxygenation. A strong negative ΔR2* and ΔR1 response was observed in veins and some tumor areas. Moderate positive ΔR2* and ΔR1 response amplitudes were found in fluid-rich tissue as in cerebrospinal fluid, peritumoral edema, and necrotic areas. The multiparametric approach was shown to increase the specificity and sensitivity of oxygen-enhanced MRI compared to measuring ΔR2* or ΔR1 alone. It is thus expected to provide an optimal tool for the identification of tissue areas with low oxygenation, e.g., in tumors with compromised oxygen supply.

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Section: Discussionmentioning

confidence: 99%

Dynamic and simultaneous MR measurement of R₁ and R₂* changes during respiratory challenges for the assessment of blood and tissue oxygenation

Remmele

Sprinkart

Müller

et al. 2012

Magnetic Resonance in Med

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“…However, vasodilatory reserve can be lost in other ways such as through infectious disease, particularly those related to herpes zoster, 33 noninfectious inflammatory conditions, 34 drug reactions, 35 neoplastic changes, 36 dementia, 29 and traumatic brain injury. 37 We anticipate that studies of τ in these conditions may further elucidate the vascular component of their underlying pathophysiology.…”

Section: Application Of Cerebrovascular Reactivity and Its Dynamicmentioning

confidence: 98%

Measuring Cerebrovascular Reactivity: The Dynamic Response to a Step Hypercapnic Stimulus

Poublanc

Crawley

Sobczyk

et al. 2015

J Cereb Blood Flow Metab

128

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We define cerebral vascular reactivity (CVR) as the ratio of the change in blood oxygen level-dependent (BOLD) magnetic resonance imaging (MRI) signal (S) to an increase in blood partial pressure of CO2 (PCO2): % Δ S/Δ PCO2 mm Hg. Our aim was to further characterize CVR into dynamic and static components and then study 46 healthy subjects collated into a reference atlas and 20 patients with unilateral carotid artery stenosis. We applied an abrupt boxcar change in PCO2 and monitored S. We convolved the PCO2 with a set of first-order exponential functions whose time constant τ was increased in 2-second intervals between 2 and 100 seconds. The τ corresponding to the best fit between S and the convolved PCO2 was used to score the speed of response. Additionally, the slope of the regression between S and the convolved PCO2 represents the steady-state CVR (ssCVR). We found that both prolongations of τ and reductions in ssCVR (compared with the reference atlas) were associated with the reductions in CVR on the side of the lesion. τ and ssCVR are respectively the dynamic and static components of measured CVR.

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“…Yet, only a few human studies combine these two conditions for the assessment of brain lesions [29], [30], [31]. During hyperoxia challenge all functional blood vessels are expected to show increased BOLD signal due to changes in blood oxygenation.…”

Section: Introductionmentioning

confidence: 99%

Hemodynamic Response Imaging: A Potential Tool for the Assessment of Angiogenesis in Brain Tumors

et al. 2012

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Blood oxygenation level dependence (BOLD) imaging under either hypercapnia or hyperoxia has been used to study neuronal activation and for assessment of various brain pathologies. We evaluated the benefit of a combined protocol of BOLD imaging during both hyperoxic and hypercapnic challenges (termed hemodynamic response imaging (HRI)). Nineteen healthy controls and seven patients with primary brain tumors were included: six with glioblastoma (two newly diagnosed and four with recurrent tumors) and one with atypical-meningioma. Maps of percent signal intensity changes (ΔS) during hyperoxia (carbogen; 95%O2+5%CO2) and hypercapnia (95%air+5%CO2) challenges and vascular reactivity mismatch maps (VRM; voxels that responded to carbogen with reduced/absent response to CO2) were calculated. VRM values were measured in white matter (WM) and gray matter (GM) areas of healthy subjects and used as threshold values in patients. Significantly higher response to carbogen was detected in healthy subjects, compared to hypercapnia, with a GM/WM ratio of 3.8 during both challenges. In patients with newly diagnosed/treatment-naive tumors (n = 3), increased response to carbogen was detected with substantially increased VRM response (compared to threshold values) within and around the tumors. In patients with recurrent tumors, reduced/absent response during both challenges was demonstrated. An additional finding in 2 of 4 patients with recurrent glioblastoma was a negative response during carbogen, distant from tumor location, which may indicate steal effect. In conclusion, the HRI method enables the assessment of blood vessel functionality and reactivity. Reference values from healthy subjects are presented and preliminary results demonstrate the potential of this method to complement perfusion imaging for the detection and follow up of angiogenesis in patients with brain tumors.

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Analysing the response in R2* relaxation rate of intracranial tumours to hyperoxic and hypercapnic respiratory challenges: initial results

Abstract: The spatially resolved determination of R2* changes reveals the individual heterogeneous response characteristic of intracranial human tumours during hyperoxic and hypercapnic respiratory challenges.

Cited by 14 publications

References 49 publications

Dynamic and simultaneous MR measurement of R₁ and R₂* changes during respiratory challenges for the assessment of blood and tissue oxygenation

Dynamic and simultaneous MR measurement of R₁ and R₂* changes during respiratory challenges for the assessment of blood and tissue oxygenation

Measuring Cerebrovascular Reactivity: The Dynamic Response to a Step Hypercapnic Stimulus

Hemodynamic Response Imaging: A Potential Tool for the Assessment of Angiogenesis in Brain Tumors

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Analysing the response in R2* relaxation rate of intracranial tumours to hyperoxic and hypercapnic respiratory challenges: initial results

Abstract: The spatially resolved determination of R2* changes reveals the individual heterogeneous response characteristic of intracranial human tumours during hyperoxic and hypercapnic respiratory challenges.

Cited by 14 publications

References 49 publications

Dynamic and simultaneous MR measurement of R1 and R2* changes during respiratory challenges for the assessment of blood and tissue oxygenation

Dynamic and simultaneous MR measurement of R1 and R2* changes during respiratory challenges for the assessment of blood and tissue oxygenation

Measuring Cerebrovascular Reactivity: The Dynamic Response to a Step Hypercapnic Stimulus

Hemodynamic Response Imaging: A Potential Tool for the Assessment of Angiogenesis in Brain Tumors

Contact Info

Product

Resources

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Dynamic and simultaneous MR measurement of R₁ and R₂* changes during respiratory challenges for the assessment of blood and tissue oxygenation

Dynamic and simultaneous MR measurement of R₁ and R₂* changes during respiratory challenges for the assessment of blood and tissue oxygenation