Publications by authors named "Yuhao Liao"

3 Publications

  • Page 1 of 1

Diffusion MRI Based Myometrium Tractography for Detection of Placenta Accreta Spectrum Disorder.

J Magn Reson Imaging 2021 Jun 21. Epub 2021 Jun 21.

Key Laboratory for Biomedical Engineering of Ministry of Education, Department of Biomedical Engineering, College of Biomedical Engineering & Instrument Science, Zhejiang University, Hangzhou, China.

Background: Prenatal diagnosis of placenta accreta spectrum (PAS) disorders is difficult. Magnetic resonance imaging (MRI) has been shown to be a useful supplementary method to ultrasound.

Purpose: To investigate diffusion MRI (dMRI) based tractography as a tool for detecting PAS disorders, and to evaluate its performance compared with anatomical MRI.

Study Type: Prospective.

Population: Forty-seven pregnant women in the third trimester with risk factors for PAS.

Field Strength/sequence: Using fast imaging employing steady-state acquisition and high-angular resolution dMRI at 1.5 Tesla.

Assessment: Diagnosis of PAS was performed by three radiologists based on the dMRI-based feature of myometrial fiber discontinuity and on commonly used anatomical features including presence of dark band, discontinuous myometrium and bladder wall interruption. We evaluated the sensitivity, specificity, accuracy, and area-under-the-curve (AUC) of the individual features and established an integrated model with random forest analysis.

Statistical Tests: Maternal age and gestational age at scan were compared between PAS and control group using a t-test, and childbearing history was compared using a chi-squared test. The random forest model was employed to combine the anatomical and dMRI features with 5-fold cross-validation, and the weight of each feature was normalized to evaluate its importance in predicting PAS.

Results: Based on surgical pathology reports, 16 out of 47 patients had confirmed PAS. The anatomical feature of dark bands and tractography marker achieved the highest AUC of 0.842 for predicting PAS, and the integrated anatomical and tractography features further improved the AUC of 0.880 with an accuracy of 87.2%. The tractography feature contributed most (30.1%) to the integrated model.

Data Conclusion: Myometrial tractography demonstrated superior performance in detecting PAS. Moreover, the combination of dMRI-based tractography and anatomical MRI could potentially improve the diagnosis of PAS disorders in clinical practice.

Level Of Evidence: 2 TECHNICAL EFFICACY STAGE: 2.
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http://dx.doi.org/10.1002/jmri.27794DOI Listing
June 2021

Probing the ballistic microcirculation in placenta using flow-compensated and non-compensated intravoxel incoherent motion imaging.

Magn Reson Med 2021 01 27;85(1):404-412. Epub 2020 Jul 27.

Key Laboratory for Biomedical Engineering of Ministry of Education, Department of Biomedical Engineering, College of Biomedical Engineering & Instrument Science, Zhejiang University, Hangzhou, China.

Purpose: Intravoxel incoherent motion (IVIM) imaging is widely used to evaluate microcirculatory flow, which consists of diffusive and ballistic flow components. We proposed a joint use of flow-compensated (FC) and non-compensated (NC) diffusion gradients to probe the fraction and velocity of ballistic flow in the placenta.

Methods: Forty pregnant women were included in this study and scanned on a 1.5T clinical scanner. FC and NC diffusion MRI (dMRI) sequences were achieved using a pair of identical or mirrored bipolar gradients. A joint FC-NC model was established to estimate the fraction (f ) and velocity (v ) of the ballistic flow. Conventional IVIM parameters (f, D, and D*) were obtained from the FC and NC data, separately. The v and f·D*, as placental flow velocity measurements, were correlated with the umbilical-artery Doppler ultrasound indices and gestational ages.

Results: The ballistic flow component can be observed from the difference between the FC and NC dMRI signal decay curves. v fitted from the FC-NC model showed strong correlations with umbilical-artery impedance indices, the systolic-to-diastolic (SD) ratio and pulsatility index (PI), with correlation coefficients of 0.65 and 0.62. The f·D* estimated from the NC data positively correlated with SD and PI, while the FC-based f·D* values showed weak negative correlations. Significant gestational-age dependence was also found in the flow velocity measurements.

Conclusion: Our results demonstrated the feasibility of using FC and NC dMRI to noninvasively measure ballistic flow velocity in the placenta, which may be used as a new marker to evaluate placenta microcirculation.
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http://dx.doi.org/10.1002/mrm.28426DOI Listing
January 2021

Geographical distribution and risk assessment of dichlorodiphenyltrichloroethane and its metabolites in Perna viridis mussels from the northern coast of the South China Sea.

Mar Pollut Bull 2020 Feb 29;151:110819. Epub 2020 Jan 29.

State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.

Mussels (Perna viridis) were collected from the northern coast of the South China Sea (NSCS) to investigate the geographical distribution and potential risk of dichlorodiphenyltrichloroethane and its metabolites (DDTs). DDTs had concentrations that ranged from 248 ng/g to 4650 ng/g lipid weight (lw), with an average of 807 ± 932 ng/ng lw. A comparison of the levels of DDTs in mussels indicated that the NSCS is still one of the most polluted areas in the world, although a decreasing trend was observed. DDT metabolites were predominant in all samples, suggesting that historical residue was the main source of DDT pollution. However, there were new inputs of DDTs which likely associated with antifouling paints. The human health risk assessment revealed that the current concentrations of DDTs in mussels might pose little health risk for the consumers.
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http://dx.doi.org/10.1016/j.marpolbul.2019.110819DOI Listing
February 2020
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