Variation of the relaxographic “shutter‐speed” for transcytolemmal water exchange affects the CR bolus‐tracking curve shape

Yankeelov, Thomas E.; Rooney, William D.; Li, Xin; Springer, Charles S.

doi:10.1002/mrm.10624

Cited by 173 publications

(382 citation statements)

References 41 publications

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“…The SM assumes that the equilibrium water intercompartmental exchange systems remain in the FXL: it is FXLconstrained (FXL-c). We also used the FXR-and SXR-allowed (FXR-a and SXR-a) versions of the first-generation ShutterSpeed Model (SSM1), BOLus Enhanced Relaxation Overview (BOLERO) (8,11). In the SM analyses, the parameters varied are K trans and v e , while the i value is (implicitly) zero (11,13,14).…”

Section: Resultsmentioning

confidence: 99%

“…The model has the constraints that i is vanishingly small (the FXL) and that the transverse relaxation factor [exp(ϪTE⅐R 2 ‫ء‬ )] ϭ 1. The dashed curve shows the characteristic undershoot at the beginning, followed by overshoot and then undershoot during the washout (11,13,14). The K trans and v e parameter values from this fitting are listed in Table 1.…”

Section: Resultsmentioning

confidence: 99%

“…This corollary is not valid (2,6), and its assumption can effectively short circuit MRI determination of CR compartmentalization (2, 7)-the pharmacokinetic essence. In a series of papers (2,5,6,(8)(9)(10)(11)(12)(13)(14)(15)(16), we have examined the significance of this implication. We refer to models incorporating equilibrium exchange effects in the pharmacokinetic derivation as belonging to the shutter-speed model (SSM) family.…”

Section: Dynamic Nuclear Magnetic Resonance (Dnmr)mentioning

confidence: 99%

“…None achieve anywhere near 100% positive predictive value (PPV) (the best is 54%, for SM K trans ). Compared with the SSM, the SM generally underestimates the parameter value [albeit with some precision benefit from reduced parametrization (11,14)], except for k ep (Fig. 2D) and (1 Ϫ v e )/ i (Fig.…”

Section: Comparison Of Pharmacokinetic Model and Gold Standard Pathologymentioning

confidence: 99%

“…1D Inset) was generated by simply averaging these trajectories and used for each of the 16 SK subjects. These AIF time-course data were interpolated by using a 7-parameter empirical expression (11). For each patient, an ROI was manually drawn to circumscribe the entire enhanced lesion in a DCE-MRI image exhibiting near maximal enhancement.…”

Section: Dce-mri Pharmacokineticmentioning

confidence: 99%

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Dynamic NMR effects in breast cancer dynamic-contrast-enhanced MRI

Huang

Morris

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

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147

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The passage of a vascular-injected paramagnetic contrast reagent (CR) bolus through a region-of-interest affects tissue 1 H2O relaxation and thus MR image intensity. For longitudinal relaxation [R1 ϵ (T1) ؊1 ], the CR must have transient molecular interactions with water. Because the CR and water molecules are never uniformly distributed in the histological-scale tissue compartments, the kinetics of equilibrium water compartmental interchange are competitive. In particular, the condition of the equilibrium transcytolemmal water exchange NMR system sorties through different domains as the interstitial CR concentration, [CRo], waxes and wanes. Before CR, the system is in the fast-exchange-limit (FXL). Very soon after CRo arrival, it enters the fast-exchange-regime (FXR). Near maximal [CRo], the system could enter even the slowexchange-regime (SXR). These conditions are defined herein, and a comprehensive description of how they affect quantitative pharmacokinetic analyses is presented. Data are analyzed from a population of 22 patients initially screened suspicious for breast cancer. After participating in our study, the subjects underwent biopsy/pathology procedures and only 7 (32%) were found to have malignancies. The transient departure from FXL to FXR (and apparently not SXR) is significant in only the malignant tumors, presumably because of angiogenic capillary leakiness. Thus, if accepted, this analysis would have prevented the 68% of the biopsies that proved benign.water exchange ͉ screening ͉ shutter speed

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Dynamic Nuclear Magnetic Resonance (Dnmr)mentioning

confidence: 99%

Section: Comparison Of Pharmacokinetic Model and Gold Standard Pathologymentioning

confidence: 99%

Section: Dce-mri Pharmacokineticmentioning

confidence: 99%

See 3 more Smart Citations

Dynamic NMR effects in breast cancer dynamic-contrast-enhanced MRI

Huang

Morris

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

147

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show abstract

Springer Jr, Charles S.: The NMR Shutter Speed

Springer

2010

Encyclopedia of Magnetic Resonance

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Comparison of dynamic contrast‐enhanced MRI and quantitative SPECT in a rat glioma model

Skinner¹,

Yankeelov²,

Peterson³

et al. 2012

Contrast Media & Molecular

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Pharmacokinetic modeling of dynamic contrast enhanced (DCE)-MRI data provides measures of the extracellular volume fraction (ve) and the volume transfer constant (Ktrans) in a given tissue. These parameter estimates may be biased, however, by confounding issues such as contrast agent and tissue water dynamics, or assumptions of vascularization and perfusion made by the commonly used model. In contrast to MRI, radiotracer imaging with SPECT is insensitive to water dynamics. A quantitative dual-isotope SPECT technique was developed to obtain an estimate of ve in a rat glioma model for comparison to the corresponding estimates obtained using DCE-MRI with a vascular input function (VIF) and reference region model (RR). Both DCE-MRI methods produced consistently larger estimates of ve in comparison to the SPECT estimates, and several experimental sources were postulated to contribute to these differences.

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Variation of the relaxographic “shutter‐speed” for transcytolemmal water exchange affects the CR bolus‐tracking curve shape

Abstract: Contrast reagents (CRs) may enter the tissue interstitium for a period after a vascular bolus injection. As the amount of interstitial CR increases, the longitudinal relaxographic NMR "shutter-speed" (T

Cited by 173 publications

References 41 publications

Dynamic NMR effects in breast cancer dynamic-contrast-enhanced MRI

Dynamic NMR effects in breast cancer dynamic-contrast-enhanced MRI

Springer Jr, Charles S.: The NMR Shutter Speed

Comparison of dynamic contrast‐enhanced MRI and quantitative SPECT in a rat glioma model

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