Fetal functional magnetic resonance imaging study

Title: Fetal functional magnetic resonance imaging study Author: Sun Ziyan Degree-granting units: Huazhong University of Science and Technology Keywords: fetus;; magnetic resonance imaging;; spectroscopy;; pregnancy;; prenatal; fetus;; magnetic resonance imaging;; spectroscopy;; pregnancy;; prenatal Abstract:
Part of fetal brain single voxel proton Magnetic lifter spectroscopy of the feasibility study
Dynamic magnetic resonance imaging with the purpose of
Of fetal brain single voxel magnetic resonance spectroscopy is feasible. Materials and methods 50 cases of fetal gestational age 20-40 the number of points according to amniotic fluid volume
Into three groups (more than 6 cases of amniotic fluid volume, normal amniotic fluid group, 21 cases and 23 cases of amniotic fluid less), dynamic magnetic resonance imaging using SSFSE vector film
Like surface observation of fetal head movement, magnetic resonance spectroscopy in the positioning of the fetus on the basis of three orthogonal planes using single voxel point-resolved spectroscopy
(PRESS) sequence line single voxel MR spectroscopy acquisition (TE = 144ms), MRS acquisition is triggered using the breathing technique. Results of multiple amniotic fluid volume,
Normal group and the amniotic fluid http://www.999magnet.com/products/131-magnetic-lifter amniotic fluid amniotic fluid index less groups, respectively (8.0 ± 0.7) cm, normal amniotic fluid volume group and too little amniotic fluid amniotic fluid group
Index, respectively (5.7 ± 1.4) cm and (3.8 ± 1.4) cm, the differences were statistically significant (F = 17.95, P <0.001), polyhydramnios
Frequent fetal movement group, MR imaging can be observed film fetal body parts of more than flip, stretch, and turned around, collecting magnetic resonance spectroscopy to distinguish
, Lower, metabolites on the line split into a jagged peak, spectrum a success rate of 0 (0 / 6), amniotic fluid volume normal fetal head movement
Reduced, lower resolution magnetic resonance spectroscopy acquisition, metabolites can be distinguished in the spectrum, but has obvious noise, the success rate of spectral
42.58% (9 / 21), oligohydramnios, fetal activity was limited group, magnetic resonance spectroscopy acquisition success rate, metabolites on the line to distinguish
Rate. 95.65% success rate spectrum (22/23), normal amniotic fluid volume and amniotic fluid group composed of the power difference was less significant
(X ~ 2 = 4.21, P <0.05). Conclusion proton spectroscopic imaging of fetal brain is feasible, in the normal fetal brain development and disease diagnosis side
Surface has an important value.
The second part of the normal fetal brain development in magnetic resonance spectroscopy study
Objective To investigate the normal fetal
Child brain development and changes in metabolite levels. Methods 35 cases of pregnant women met the inclusion criteria, of which 12 cases of mid-pregnancy, late pregnancy 23
Cases, gestational age 20 weeks to 40 weeks, mean gestational age 34.6 weeks. Within 1-2 days after ultrasound use single-shot fast spin-echo sequence
(SSFSE) line of conventional MR scanning of fetal brain, fetal brain scanning plane including axial, coronal and sagittal. Three orthogonal in the fetal brain
Plane location on the basis of the basal ganglia and the semi-oval center region of interest (VOI) were triggered using breathing techniques, the use of fixed-point resolution wave
Spectral sequence (PRESS) single voxel ~ 1H MRS line scan, (TE, respectively 144ms and 35ms). MRS measurements are given automatically by the machine, the measured
Set of metabolites, including N-acetyl aspartate (NAA), choline (Cho), creatine compounds (Cr), inositol (mI), Valley
Acid and glutamine (Glx), etc. Other parameters include the rms noise (RMS noise) and the creatine signal to noise ratio (Cr SNR). Select
Segment of the study group with gestational age matched 16 normal fetuses as controls. Results of normal fetal head circumference, biparietal diameter line, abdominal circumference, femur length and
No significant difference between the control group, brain MRI and post-natal examination found no abnormalities, TE = 144ms, the fetal brain MRS can detect three
Major peaks, respectively, Cho peak, located at 3.2ppm, Cr peak, located at 3.0ppm, NAA peak, located at 2.02ppm. Cho peak for the first
Peak before 34 weeks pregnant, Cr peak for the second peak after 34 weeks pregnant, NAA peak for the second peak, and the newborn after birth, similar spectrum, NAA
Peak at 22 weeks pregnant can already tell, can not detect lactic acid or a lower peak level, MI peaks can be detected, located 3.56ppm; TE = 35ms
, Can be detected Cho peak, Cr peak, MI peak, NAA peak and the peak of glutamate and glutamine (Glx). As gestational age increases, TE = 144
Time, NAA / S increased (P = 0.007, r ~ 2 = 0.20), Cho / S reduced (P = 0.005, r ~ 2 = 0.22), Cr / S changes with gestational age is unknown
Significant (P = 0.96, r ~ 2 = 0.001). TE = 35ms, when, NAA / S increased (P = 0.05, r ~ 2 = 0.21), Cho / S decreased (P = 0.014,
r ~ 2 = 0.17), MI peak decreased (P = 0.045, r ~ 2 = 0.12), Cr / S did not change significantly with gestational age (P = 0.2, r ~ 2 = 0.049).

The third part of the normal fetal brain development of MRI and DTI research
The purpose of combined single-shot spin-echo sequence and diffusion tensor imaging
Observe the performance of normal fetal brain development. Methods SSFSE sequence and diffusion tensor imaging of 17 cases of 20 to 39 weeks of normal fetal intrauterine
Child brain. Gestational age assessment based on the maturity of the brain back, gray and white matter of stratification, ADC maps and FA maps in different parts of the brain tissue level measurement
Both diffusivity and fractional anisotropy values, and its statistical analysis. Results (1) 20 to 23 weeks of fetal brain structures form the basic shape
Into, this section shows that the brain showed a gestational age of five-layer structure of a typical 24 to 27 weeks of gestation the fetus was a typical three-layer structure. Remaining 27 weeks leave after 2
Layer structure. (2) 20 weeks cortex is smooth, lateral fissure can be seen, with increasing gestational age, cortical tortuous, concave, gradually gyrus
, Followed by the formation of sulci are deeper, 30 weeks gyri, sulci obvious. (3) frontal lobe, occipital lobe white matter and basal ganglia ADC Mean
Were 1.83 ± 0.3μm ~ 2/ms, 1.75 ± 0.1μm ~ 2/ms and 1.65 ± 0.1μm ~ 2/ms, the mean ADC value of CSF
2.9 ± 0.6μm ~ 2/ms. Basal ganglia and the frontal lobe, occipital lobe white matter mean ADC significantly. Frontal lobe, occipital lobe and basal ganglia
Mean ADC value decreased with increasing age, a linear negative correlation with age. (4) 20 weeks pregnant can be traced to the sensory-motor fibers in the brain
Paraventricular, located in the middle of the band, as gestational age increased, the bilateral internal capsule limb of the sensory-motor fibers can clearly show the direction of the head and tail was
. After 20 weeks of pregnancy can be traced to the knee and press the corpus callosum white matter fibers, internal capsule, with the hind legs of the FA values ​​increased with increasing gestational age. Conclusion Alliance
And DTI imaging sequence together SSFSE accurate and comprehensive evaluation of the fetal brain can be real with the gestational age of maturation process variation.

The fourth part of the fetal three-dimensional magnetic resonance imaging study
Objective To investigate the three-dimensional magnetic resonance imaging in normal and abnormal structure of the fetal
Aspects of clinical value. Methods 50 cases of ultrasound diagnosis of fetal congenital malformations or suspected fetal maternal line of MRI, aged 21 to 32 years,
Average of 25.4 years, 20 to 38 weeks gestational age, average 28.6 weeks. MR imaging using single-shot fast spin-echo sequence (SSFSE), in pregnant
Abdominal three-plane positioning of women on the basis of routine fetal head and chest and abdomen axial, coronal and sagittal scans, 41 patients with three-dimensional fast
Imaging steady state precession sequence (3D-FIESTA) line of three-dimensional fetal imaging. 9 cases using three-dimensional spoiled gradient echo sequence (3D-FSPGR) sequence
Line three-dimensional imaging of fetal colon, three-dimensional image transmission to the image post-processing workstation. MRI, ultrasound examination at 1 to 2 days
, MRI examination of the fetal autopsy and follow-up. 2D and 3D ultrasound and MR images by two physicians and two ultrasound
Radiologists double-blind analysis. After the results of autopsy and follow-up study of fetal malformations in 58 cases, of which 44 single malformation cases,
4 cases of two malformations, 2 cases of three malformations, (of which eight cases of anencephaly, meningoencephalocele 3 cases, small head malformation, cervical cystic lymph
The tumor in 9 cases, conjoined twins in 4 cases, 5 cases of congenital diaphragmatic hernia, Hirschsprung's disease in 4 cases, 6 cases omphalocele, A ventral cleft in 4 cases, different body pedicle
Normal in 1 case, clubfoot five cases), 3D-US checks true positive rate was 89.66% (52/58), specificity of 98.11% (52/53),
3D-MRI examination of true-positive rate was 93.10% (54/58), specificity of 98.18%, the difference was not statistically significant. However, a total of three-dimensional magnetic
Resonance imaging field of vision, organization, high resolution, multi-plane can observe the surface structure of the fetus and fetal disease. Discuss the three-dimensional MRI can clearly
To the surface structure of the fetus surface reconstruction, can visualize the structure of the surface features of interest, three-dimensional shape and surface structure between the bit
Relation that can serve as an important supplement to two-dimensional imaging, ultrasound, especially for those who can not be confirmed or ambiguous cases, the diagnosis side
Law is an effective supplement. Degree Year: 2009