Dataset Information

Improved quantification of cerebral hemodynamics using individualized time thresholds for assessment of peak enhancement parameters derived from dynamic susceptibility contrast enhanced magnetic resonance imaging.

ABSTRACT:

Purpose

Assessment of cerebral ischemia often employs dynamic susceptibility contrast enhanced magnetic resonance imaging (DSC-MRI) with evaluation of various peak enhancement time parameters. All of these parameters use a single time threshold to judge the maximum tolerable peak enhancement delay that is supposed to reliably differentiate sufficient from critical perfusion. As the validity of this single threshold approach still remains unclear, in this study, (1) the definition of a threshold on an individual patient-basis, nevertheless (2) preserving the comparability of the data, was investigated.

Methods

The histogram of time-to-peak (TTP) values derived from DSC-MRI, the so-called TTP-distribution curve (TDC), was modeled using a double-Gaussian model in 61 patients without severe cerebrovascular disease. Particular model-based zf-scores were used to describe the arterial, parenchymal and venous bolus-transit phase as time intervals Ia,p,v. Their durations (delta Ia,p,v), were then considered as maximum TTP-delays of each phase.

Results

Mean-R2 for the model-fit was 0.967. Based on the generic zf-scores the proposed bolus transit phases could be differentiated. The Ip-interval reliably depicted the parenchymal bolus-transit phase with durations of 3.4 s-10.1 s (median = 4.3s), where an increase with age was noted (∼30 ms/year).

Conclusion

Individual threshold-adjustment seems rational since regular bolus-transit durations in brain parenchyma obtained from the TDC overlap considerably with recommended critical TTP-thresholds of 4 s-8 s. The parenchymal transit time derived from the proposed model may be utilized to individually correct TTP-thresholds, thereby potentially improving the detection of critical perfusion.

SUBMITTER: Nasel C

PROVIDER: S-EPMC4270773 | biostudies-literature | 2014

REPOSITORIES: biostudies-literature

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Publications

Improved quantification of cerebral hemodynamics using individualized time thresholds for assessment of peak enhancement parameters derived from dynamic susceptibility contrast enhanced magnetic resonance imaging.

Nasel Christian C Kalcher Klaudius K Boubela Roland R Moser Ewald E

PloS one 20141218 12

<h4>Purpose</h4>Assessment of cerebral ischemia often employs dynamic susceptibility contrast enhanced magnetic resonance imaging (DSC-MRI) with evaluation of various peak enhancement time parameters. All of these parameters use a single time threshold to judge the maximum tolerable peak enhancement delay that is supposed to reliably differentiate sufficient from critical perfusion. As the validity of this single threshold approach still remains unclear, in this study, (1) the definition of a th ...[more]

PMID: 25521121

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Project description:ObjectivesQuantitative computed tomography (CT) plays an increasingly important role in phenotyping airway diseases. Lung parenchyma and airway inflammation could be quantified by contrast enhancement at CT, but its investigation by multiphasic examinations is limited. We aimed to quantify lung parenchyma and airway wall attenuation in a single contrast-enhanced spectral detector CT acquisition.MethodsFor this cross-sectional retrospective study, 234 lung-healthy patients who underwent spectral CT in four different contrast phases (non-enhanced, pulmonary arterial, systemic arterial, and venous phase) were recruited. Virtual monoenergetic images were reconstructed from 40-160 keV, on which attenuations of segmented lung parenchyma and airway walls combined for 5th-10th subsegmental generations were assessed in Hounsfield Units (HU) by an in-house software. The spectral attenuation curve slope between 40 and 100 keV (λHU) was calculated.ResultsMean lung density was higher at 40 keV compared to that at 100 keV in all groups (p < 0.001). λHU of lung attenuation was significantly higher in the systemic (1.7 HU/keV) and pulmonary arterial phase (1.3 HU/keV) compared to that in the venous phase (0.5 HU/keV) and non-enhanced (0.2 HU/keV) spectral CT (p < 0.001). Wall thickness and wall attenuation were higher at 40 keV compared to those at 100 keV for the pulmonary and systemic arterial phase (p ≤ 0.001). λHU for wall attenuation was significantly higher in the pulmonary arterial (1.8 HU/keV) and systemic arterial (2.0 HU/keV) compared to that in the venous (0.7 HU/keV) and non-enhanced (0.3 HU/keV) phase (p ≤ 0.002).ConclusionsSpectral CT may quantify lung parenchyma and airway wall enhancement with a single contrast phase acquisition, and may separate arterial and venous enhancement. Further studies are warranted to analyze spectral CT for inflammatory airway diseases.Key points• Spectral CT may quantify lung parenchyma and airway wall enhancement with a single contrast phase acquisition. • Spectral CT may separate arterial and venous enhancement of lung parenchyma and airway wall. • The contrast enhancement can be quantified by calculating the spectral attenuation curve slope from virtual monoenergetic images.

Dataset Information

Improved quantification of cerebral hemodynamics using individualized time thresholds for assessment of peak enhancement parameters derived from dynamic susceptibility contrast enhanced magnetic resonance imaging.

Purpose

Methods

Results

Conclusion

Publications

Improved quantification of cerebral hemodynamics using individualized time thresholds for assessment of peak enhancement parameters derived from dynamic susceptibility contrast enhanced magnetic resonance imaging.

Similar Datasets

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