1. Susceptibility weighted imaging (SWI) is an MR technique invented by our group which uses T2* weighted magnitude and phase images to improve visualization of small veins and microhemorrhages. SWI also allows quantitative assessment of blood oxygenation, using principles of quantitative susceptibility mapping. For the first time, we demonstrated that the fetal brain venous system could be imaged using SWI/MRI. The cerebral venous vasculature was visible in 86.4% of cases. The image quality was scored as being of diagnostic quality (68.2%);diagnostic quality with minor artifacts (22.7%);and non-diagnostic (9.1%). We have shown that MRI/SWI are of value in the differential diagnosis of hemorrhage vs. calcification in fetuses with brain lesions this is not possible with any other diagnostic technique. 2. Patients with a sonographic short cervix are at increased risk for preterm delivery, and vaginal progesterone decreases the rate of early preterm birth by 45%. However, a fraction of patients with a short cervix do not deliver preterm, and therefore, do not need treatment (either surgical or medical) at present, such patients cannot be identified. Ultrasound derived elastography can be used to evaluate stiffness of tissue, and is based on the estimation of tissue displacement (strain) within a defined region of interest when oscillatory compression is applied. We reported a study in which strain estimations were prospectively determined in 262 women (8-40 weeks of gestation). Mean strain rates were 14% and 5% greater among parous women with and without a history of PTD, respectively (vs. nulliparous women), and were 13% greater among women with a cervical length of 25-30 mm (vs. >30 mm). Cervical tissue strain was more strongly associated with cervical length than gestational age. To determine if there was an association between cervical strain and spontaneous preterm delivery, elastography was performed in 189 women from 16-24 weeks of gestation. Low strain values in the internal os were significantly associated with a lower risk of spontaneous PTD <37 weeks of gestation. Women with strain values ≤25th percentile (representing stiff tissue) in the endocervical canal and in the entire cervix were 80% less likely to have a spontaneous PTD than those with strain values >25th percentile. Therefore, ultrasound-based elastography can serve as a tool to identify patients with a short cervix who may not require treatment. Further studies will focus on the use of shear-wave elastography, which is superior to conventional elastography because the generation of the mechanical impulse that induces tissue displacement is operator-independent. 3. A major objective for neuroscience is to build a complete diagram of brain connections. Although this is being pursued in adults and children and is considered a high priority for U.S. (Human Brain Project), little is known about functional neuroconnectivity during human fetal life. By leveraging the characterization of low frequency intrinsic fluctuations in the blood oxygen level-dependent (BOLD) signals, functional connectivity MRI (fcMRI) provides information about macroscale brain organization. This approach is useful in determining emerging neural circuits in the human fetus this is important because many neurodevelopmental disorders, such as autism spectrum disorders, learning disabilities and cpp, may result from disorders of neuroconnectivity. Building on our pioneering studies on fetal neuroconnectivity (Science Transl Med 2013), we have now applied graph theoretical analysis to gain insight into human fetal brain connectivity. Utilizing resting state functional magnetic resonance imaging (fMRI) data from 33 healthy human fetuses at 19 to 39 weeks of gestational age (GA), our analyses revealed that the human fetal brain has modular organization, and that such modules overlap with functional systems observed in the neonatal period. Age-related differences between younger (GA <31 weeks) and older (GA >31 weeks) fetuses demonstrate that brain modularity decreases, and connectivity of the posterior cingulate to other brain networks becomes more negative, with advancing gestational age. These results suggest that the human fetus has the capacity for information processing well before birth.
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