In utero Perfusing Fraction Maps in Normal and Growth Restricted Pregnancy Measured Using IVIM Echo-Planar MRI

Moore, Rachel J.; Strachan, Bryony; Tyler, Damian J.; Duncan, Keith; Baker, Philip N.; Worthington, B. S.; Johnson, I. R.; Gowland, Penny A.

doi:10.1053/plac.2000.0567

Cited by 109 publications

(95 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This model provides a framework for anatomically based modelling of the placenta and can be individualized using morphometric-or ultrasound-based data on placental shape and large vessel structure, as has been demonstrated effectively in anatomically based models of other organs [33]. Combined with models of uterine perfusion, we anticipate that this model framework could also be used to assess placental flow heterogeneity and its changes in pathology as observed in MRI studies [46]. It also lends itself to adaption for simulation of function in early pregnancy, where capillary beds are not completely formed.…”

Section: Discussionmentioning

confidence: 94%

“…Both excessive and sparse capillary branching are associated with changes in flow heterogeneity in our model. Flow distribution and heterogeneity in the placenta have been assessed in diabetic pregnancies and growth-restricted pregnancies using MRI [46,51], although this method allows only visualization of a combination of feto -placental and utero-placental flow, so is not currently directly comparable to the model. However, consideration of both utero-placental and feto -placental contributions to flow heterogeneity should be an important consideration in the future to allow direct comparison with this type of imaging study.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Multiscale modelling of the feto–placental vasculature

et al. 2015

View full text Add to dashboard Cite

One contribution of 11 to a theme issue 'Multiscale modelling in biomechanics: theoretical, computational and translational challenges'. The placenta provides all the nutrients required for the fetus through pregnancy. It develops dynamically, and, to avoid rejection of the fetus, there is no mixing of fetal and maternal blood; rather, the branched placental villi 'bathe' in blood supplied from the uterine arteries. Within the villi, the feto-placental vasculature also develops a complex branching structure in order to maximize exchange between the placental and maternal circulations. To understand the development of the placenta, we must translate functional information across spatial scales including the interaction between macro-and micro-scale haemodynamics and account for the effects of a dynamically and rapidly changing structure through the time course of pregnancy. Here, we present steps towards an anatomically based and multiscale approach to modelling the feto-placental circulation. We assess the effect of the location of cord insertion on feto-placental blood flow resistance and flow heterogeneity and show that, although cord insertion does not appear to directly influence feto-placental resistance, the heterogeneity of flow in the placenta is predicted to increase from a 19.4% coefficient of variation with central cord insertion to 23.3% when the cord is inserted 2 cm from the edge of the placenta. Model geometries with spheroidal and ellipsoidal shapes, but the same volume, showed no significant differences in flow resistance or heterogeneity, implying that normal asymmetry in shape does not affect placental efficiency. However, the size and number of small capillary vessels is predicted to have a large effect on feto-placental resistance and flow heterogeneity. Using this new model as an example, we highlight the importance of taking an integrated multi-disciplinary and multiscale approach to understand development of the placenta.

show abstract

Section: Discussionmentioning

confidence: 94%

Section: Discussionmentioning

confidence: 99%

Multiscale modelling of the feto–placental vasculature

et al. 2015

View full text Add to dashboard Cite

show abstract

“…8 This leads to reduced uteroplacental perfusion 9,10 ; in turn, this may impact fetoplacental vascular development and result in increased resistance in the umbilical circulation. 11 In addition, hypoperfusion of the placenta also causes an increase in the production of reactive oxygen species, such as superoxide anions, which may reduce vasodilation further because of the scavenging of NO.…”

mentioning

confidence: 99%

Sildenafil Citrate Rescues Fetal Growth in the Catechol- O -Methyl Transferase Knockout Mouse Model

et al. 2012

View full text Add to dashboard Cite

Abstract-Preeclampsia and fetal growth restriction are responsible for the majority of maternal and perinatal morbidity and mortality associated with complicated pregnancies. Although their etiologies are complex and multifactorial, both are associated with increased uterine artery resistance. Sildenafil citrate is able to rescue the dysfunction observed ex vivo in uterine arteries of women with preeclampsia. The ability of sildenafil citrate to increase uterine artery vasodilation, thereby decreasing uterine artery resistance and, hence, ameliorated preeclampsia and fetal growth restriction, was tested in a mouse model of preeclampsia, the catechol-O-methyl transferase knockout mouse (COMT Ϫ/Ϫ ). COMT Ϫ/Ϫ and C57BL/6J mice were treated (0.2 mg/mL in drinking water, nϭ6 -12) from gestational day 12.5 to 18.5. Measures of pup growth, including body weight, crown/rump length, and abdominal circumference, were reduced in COMT Ϫ/Ϫ mice; this was normalized after treatment with Sildenafil. COMT Ϫ/Ϫ mice also demonstrated abnormal umbilical Doppler waveforms, including reverse arterial blood flow velocity. This was normalized after treatment with Sildenafil. Abnormal uterine artery Doppler waveforms were not demonstrated in COMT Ϫ/Ϫ mice, although ex vivo responses of uterine arteries to phenylephrine were increased; moreover, treatment with Sildenafil did improve ex vivo sensitivity to an endothelium-dependent vasodilator. The data presented here demonstrate that Sildenafil can rescue pup growth and improve abnormal umbilical Doppler waveforms, providing support for a potential new therapeutic strategy targeting fetal growth restriction. (Hypertension. 2012;59:1021-1028.) • Online Data Supplement Key Words: preeclampsia Ⅲ fetal growth restriction Ⅲ mice Ⅲ uterine artery Ⅲ umbilical artery P reeclampsia (PE) and fetal growth restriction (FGR) are pregnancy-specific disorders that complicate Յ10% of all pregnancies.1 Together they are responsible for the majority of maternal and fetal morbidity and mortality associated with complicated pregnancies.2,3 PE, characterized by the onset of hypertension and proteinuria during pregnancy, is a leading cause of maternal mortality. 4,5 It is also associated with an increased risk of stillbirth, sudden infant death, and FGR.1 FGR, which is defined as a fetus that fails to reach its genetic growth potential, may be observed in the presence or absence of PE. It is associated with a greatly increased risk of perinatal mortality and stillbirth 6 ; smaller size at birth is also associated with longer-term health consequences, such as an increased risk of developing cardiovascular disease and/or metabolic syndrome later in life.7 There are currently only limited treatment options available for PE and none for FGR; an effective therapeutic strategy would have major clinical significance.The etiology of PE and FGR is complex and as yet poorly understood; common to both conditions, however, is an increase in uterine artery resistance.8 This leads to reduced uteroplacental perfusion 9,10 ;...

show abstract

“…The water molecule motion can be assessed using diffusion-weighted imaging (DWI) and can then be separated mathematically in the two components of diffusion and perfusion. In the last years, this technique has been investigated in different organs such as liver, brain and placenta [7][8][9][10][11]. Extensive clinical application, however, has not yet been reached, probably because the method is relatively prone to artifacts and provides only limited dynamic range of perfusion assessment [12].…”

Section: Mr-based Perfusion Assessmentmentioning

confidence: 99%

Examination of Tissue Perfusion by Arterial Spin Labeling (ASL)

et al. 2013

View full text Add to dashboard Cite

Arterial spin labeling (ASL) is a non-invasive magnetic resonance technique for tissue perfusion quantification working without contrast media application. The method uses magnetically labeled blood protons as intrinsic tracer. Perfusion-weighted images are obtained by the signal difference between an image with proximal labeling of the arterial water protons and a control image. Initially designed for cerebral perfusion measurement, the ASL technique is increasingly being used for the evaluation of extracranial organs which might be attributed to the improvements in scanner, coil and sequence technology but also to the elaboration of postprocessing tools. In this review, the basic principles of ASL are explained. Technical difficulties in ASL sequence design are discussed. To illustrate the potential role of ASL in clinical research and diagnostics, comparison of ASL with other methods currently applied for perfusion assessment is performed. Finally, a variety of clinical applications of ASL is presented with respect to the current literature.

show abstract

In utero Perfusing Fraction Maps in Normal and Growth Restricted Pregnancy Measured Using IVIM Echo-Planar MRI

Cited by 109 publications

References 19 publications

Multiscale modelling of the feto–placental vasculature

Multiscale modelling of the feto–placental vasculature

Sildenafil Citrate Rescues Fetal Growth in the Catechol- O -Methyl Transferase Knockout Mouse Model

Examination of Tissue Perfusion by Arterial Spin Labeling (ASL)

Contact Info

Product

Resources

About