Oxygenation and hematocrit dependence of transverse relaxation rates of blood at 3T

Zhao, Jason M.; Clingman, Chekesha S.; Närväinen, M. Johanna; Kauppinen, Risto A.; Zijl, Peter C.M. van

doi:10.1002/mrm.21342

Cited by 221 publications

(296 citation statements)

References 32 publications

(72 reference statements)

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“…A quadratic model was used to describe the blood transverse relaxation rate

R_{2}^{*}

as a function of fractional blood oxygenation (Y)8, 9:

{normalR}_{2}^{*} = {normalA}^{*} + {normalB}^{*} (1 - Y) + {normalC}^{*} {(1 ‐ Y)}^{2}

where A*, B*, and C* are empirically derived coefficients dependent on B 0 and Hct.…”

Section: Methodsmentioning

confidence: 99%

“…Coefficients A*, B*, C* previously measured empirically for Hct in the range 0.21–0.57 at 3T9 were used to obtain

R_{2}^{*}

(Hct,Y) values in the full range of blood oxygenation fractions.…”

Section: Methodsmentioning

confidence: 99%

“…Paramagnetic deoxyhemoglobin increases the apparent MRI transverse relaxation rate

R_{2}^{*}

(=1/

T_{2}^{*}

) of water in blood and surrounding tissues, which provides the opportunity to image tissue oxygenation at high spatial resolution. The

T_{2}^{*}

of the vascular space is dependent on fractional blood oxygenation (Y), and can be described by a quadratic function of hematocrit levels (Hct) and magnetic field strength (B 0 ) 8, 9. Changes in

R_{2}^{*}

are used to study brain activity associated with modulated regional brain perfusion (the blood oxygen level dependent or BOLD effect) 10.…”

mentioning

confidence: 99%

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Repeatability and sensitivity of measurements in patients with head and neck squamous cell carcinoma at 3T

Panek

Welsh

Dunlop

et al. 2016

Magnetic Resonance Imaging

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PurposeTo determine whether quantitation of T2* is sufficiently repeatable and sensitive to detect clinically relevant oxygenation levels in head and neck squamous cell carcinoma (HNSCC) at 3T.Materials and MethodsTen patients with newly diagnosed locally advanced HNSCC underwent two magnetic resonance imaging (MRI) scans between 24 and 168 hours apart prior to chemoradiotherapy treatment. A multiple gradient echo sequence was used to calculate T2* maps. A quadratic function was used to model the blood transverse relaxation rate as a function of blood oxygenation. A set of published coefficients measured at 3T were incorporated to account for tissue hematocrit levels and used to plot the dependence of fractional blood oxygenation (Y) on T2* values, together with the corresponding repeatability range. Repeatability of T2* using Bland–Altman analysis, and calculation of limits of agreement (LoA), was used to assess the sensitivity, defined as the minimum difference in fractional blood oxygenation that can be confidently detected.Results T2* LoA for 22 outlined tumor volumes were 13%. The T2* dependence of fractional blood oxygenation increases monotonically, resulting in increasing sensitivity of the method with increasing blood oxygenation. For fractional blood oxygenation values above 0.11, changes in T2* were sufficient to detect differences in blood oxygenation greater than 10% (Δ T2* > LoA for ΔY > 0.1).ConclusionQuantitation of T2* at 3T can detect clinically relevant changes in tumor oxygenation within a wide range of blood volumes and oxygen tensions, including levels reported in HNSCC. J. Magn. Reson. Imaging 2016;44:72–80.

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“…A quadratic model was used to describe the blood transverse relaxation rate

R_{2}^{*}

as a function of fractional blood oxygenation (Y)8, 9:

{normalR}_{2}^{*} = {normalA}^{*} + {normalB}^{*} (1 - Y) + {normalC}^{*} {(1 ‐ Y)}^{2}

where A*, B*, and C* are empirically derived coefficients dependent on B 0 and Hct.…”

Section: Methodsmentioning

confidence: 99%

“…Coefficients A*, B*, C* previously measured empirically for Hct in the range 0.21–0.57 at 3T9 were used to obtain

R_{2}^{*}

(Hct,Y) values in the full range of blood oxygenation fractions.…”

Section: Methodsmentioning

confidence: 99%

“…Paramagnetic deoxyhemoglobin increases the apparent MRI transverse relaxation rate

R_{2}^{*}

(=1/

T_{2}^{*}

) of water in blood and surrounding tissues, which provides the opportunity to image tissue oxygenation at high spatial resolution. The

T_{2}^{*}

of the vascular space is dependent on fractional blood oxygenation (Y), and can be described by a quadratic function of hematocrit levels (Hct) and magnetic field strength (B 0 ) 8, 9. Changes in

R_{2}^{*}

are used to study brain activity associated with modulated regional brain perfusion (the blood oxygen level dependent or BOLD effect) 10.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Repeatability and sensitivity of measurements in patients with head and neck squamous cell carcinoma at 3T

Panek

Welsh

Dunlop

et al. 2016

Magnetic Resonance Imaging

View full text Add to dashboard Cite

show abstract

“…In the current studies, perfusion was increased during sustained hypoxia, 12 and the arterial and venous compartments contain increased deoxyhemoglobin, so blood oxygenation level-dependent changes will add to the observed reduction in T 2,index . From Zhao et al, 13 for a hematocrit of 0.44 the transverse relaxation rate, R 2 , can be approximated in terms of oxygen saturation, Y, as:…”

Section: Diffusion-weighted Mri Changes In Acute Mountain Sickness Jsmentioning

confidence: 99%

Cerebral Diffusion and T₂: MRI Predictors of Acute Mountain Sickness during Sustained High-Altitude Hypoxia

Hunt

Theilmann

Smith

et al. 2012

J Cereb Blood Flow Metab

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Diffusion magnetic resonance imaging (MRI) provides a sensitive indicator of cerebral hypoxia. We investigated if apparent diffusion coefficient (ADC) and transverse relaxation (T 2 ) predict symptoms of acute mountain sickness (AMS), or merely indicate the AMS phenotype irrespective of symptoms. Fourteen normal subjects were studied in two groups; unambiguous AMS and no-AMS at 3,800 m altitude (intermediate AMS scores were excluded). T 2 relaxation was estimated from a T 2 index of T 2 -weighted signal normalized by cerebrospinal fluid signal. Measurements were made in normoxia and repeated after 2 days sustained hypoxia (AMS group symptomatic and no-AMS group asymptomatic) and after 7 days hypoxia (both groups asymptomatic). Decreased ADC directly predicted AMS symptoms (Po0.05). Apparent diffusion coefficient increased in asymptomatic subjects, or as symptoms abated with acclimatization. This pattern was similar in basal ganglia, white matter, and gray matter. Corpus callosum behaved differently; restricted diffusion was absent (or rapidly reversed) in the splenium, and was sustained in the genu. In symptomatic subjects, T 2,index decreased after 2 days hypoxia and further decreased after 7 days. In asymptomatic subjects, T 2,index initially increased after 2 days, but decreased after 7 days. T 2,index changes were not predictive of AMS symptoms. These findings indicate that restricted diffusion, an indicator of diminished cerebral energy status, directly predicts symptoms of AMS in humans at altitude.

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“…[36][37][38][39][40][41][42][43][44] Additionally, concentration of other molecules relevant to lymphatic function will influence the water T 2 . It has been shown that in agarose phantoms water T 2 increases with increasing levels of NaCl.…”

Section: Physiology Of Deep and Superficial T 2 Changesmentioning

confidence: 99%

Bilateral Changes in Deep Tissue Environment After Manual Lymphatic Drainage in Patients with Breast Cancer Treatment-Related Lymphedema

Donahue

Crescenzi

Scott

et al. 2017

Lymphatic Research and Biology

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Background: Breast cancer treatment-related lymphedema (BCRL) arises from a mechanical insufficiency following cancer therapies. Early BCRL detection and personalized intervention require an improved understanding of the physiological processes that initiate lymphatic impairment. Here, internal magnetic resonance imaging (MRI) measures of the tissue microenvironment were paired with clinical measures of tissue structure to test fundamental hypotheses regarding structural tissue and muscle changes after the commonly used therapeutic intervention of manual lymphatic drainage (MLD). Methods and Results: Measurements to identify lymphatic dysfunction in healthy volunteers (n = 29) and patients with BCRL (n = 16) consisted of (1) limb volume, tissue dielectric constant, and bioelectrical impedance (i.e., non-MRI measures); (2) qualitative 3 Tesla diffusion-weighted, T 1 -weighted and T 2 -weighted MRI; and (3) quantitative multi-echo T 2 MRI of the axilla. Measurements were repeated in patients immediately following MLD. Normative control and BCRL T 2 values were quantified and a signed Wilcoxon Rank-Sum test was applied (significance: two-sided p < 0.05). Non-MRI measures yielded significant capacity for discriminating between arms with versus without clinical signs of BCRL, yet yielded no change in response to MLD. Alternatively, a significant increase in deep tissue T 2 on the involved (pre T 2 = 0.0371 -0.003 seconds; post T 2 = 0.0389 -0.003; p = 0.029) and contralateral (pre T 2 = 0.0365 -0.002; post T 2 = 0.0395 -0.002; p < 0.01) arms was observed. Trends for larger T 2 increases on the involved side after MLD in patients with stage 2 BCRL relative to earlier stages 0 and 1 BCRL were observed, consistent with tissue composition changes in later stages of BCRL manifesting as breakdown of fibrotic tissue after MLD in the involved arm. Contrast consistent with relocation of fluid to the contralateral quadrant was observed in all stages. Conclusion: Quantitative deep tissue T 2 MRI values yielded significant changes following MLD treatment, whereas non-MRI measurements did not vary. These findings highlight that internal imaging measures of tissue composition may be useful for evaluating how current and emerging therapies impact tissue function.

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Oxygenation and hematocrit dependence of transverse relaxation rates of blood at 3T

Cited by 221 publications

References 32 publications

Repeatability and sensitivity of measurements in patients with head and neck squamous cell carcinoma at 3T

Repeatability and sensitivity of measurements in patients with head and neck squamous cell carcinoma at 3T

Cerebral Diffusion and T₂: MRI Predictors of Acute Mountain Sickness during Sustained High-Altitude Hypoxia

Bilateral Changes in Deep Tissue Environment After Manual Lymphatic Drainage in Patients with Breast Cancer Treatment-Related Lymphedema

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Oxygenation and hematocrit dependence of transverse relaxation rates of blood at 3T

Cited by 221 publications

References 32 publications

Repeatability and sensitivity of measurements in patients with head and neck squamous cell carcinoma at 3T

Repeatability and sensitivity of measurements in patients with head and neck squamous cell carcinoma at 3T

Cerebral Diffusion and T2: MRI Predictors of Acute Mountain Sickness during Sustained High-Altitude Hypoxia

Bilateral Changes in Deep Tissue Environment After Manual Lymphatic Drainage in Patients with Breast Cancer Treatment-Related Lymphedema

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Cerebral Diffusion and T₂: MRI Predictors of Acute Mountain Sickness during Sustained High-Altitude Hypoxia