Ebook Atlas of fetal MRI: Part 2
➤ Gửi thông báo lỗi ⚠️ Báo cáo tài liệu vi phạmNội dung chi tiết: Ebook Atlas of fetal MRI: Part 2
Ebook Atlas of fetal MRI: Part 2
5MR Imaging of Fetal Thoracic AbnormalitiesDEBORAH LEVINEINTRODUCTIONA number of publications have described the benefit of magnetic resonance (MR) im Ebook Atlas of fetal MRI: Part 2magine in the evaluation of fetuses with thoracic abnormalities (I-10). Tn a study by Levine Ct al. (9). of 74 fetuses with thoracic abnormalities. MR imaging provides! additional inionnation over sonography in 28 (37.8%) patients. However. .MR information regarding the thorax impacted care in only Ebook Atlas of fetal MRI: Part 26/74 (8.1%) fetuses. Prenatal thoracic MR is most likely to impact care in the fetal surgery patient and in the cases where the diagnosis is unclear bEbook Atlas of fetal MRI: Part 2
y sonography.NORMAL ANATOMYLung Signal IntensityTj lung signal intensity in normal lungs is higher in older gestational age fetuses compared with youn5MR Imaging of Fetal Thoracic AbnormalitiesDEBORAH LEVINEINTRODUCTIONA number of publications have described the benefit of magnetic resonance (MR) im Ebook Atlas of fetal MRI: Part 2have been documented by MR1 studies (11). There is growth of the lungs with increasing gestational age. This growth is proportionate to fetal body size.Thoracic VascularityThe main pulmonary arteries with first-order branches can be seen as How voids in the central lungs (Fig. 5.2) (9). These arc be Ebook Atlas of fetal MRI: Part 2st visualized in the late second trimester andthroughout the third trimester when the lungs display higher signal intensity and larger size than in thEbook Atlas of fetal MRI: Part 2
e early second trimester (9). The aorta, superior vena cava, inferior vena cava, and ductal arch all can be viewed when the image is in the appropriat5MR Imaging of Fetal Thoracic AbnormalitiesDEBORAH LEVINEINTRODUCTIONA number of publications have described the benefit of magnetic resonance (MR) im Ebook Atlas of fetal MRI: Part 2e is obtained either at just the right time for a single-shot image or al the correct phase of the cardiac cycle such that cardiac gating has occurred for images obtained during: a hrealhhokl (Fig. 5.7).The Airway and EsophagusThe trachea, carina, and mainslem bronchi can be seen in many examination Ebook Atlas of fetal MRI: Part 2s of the chest (Fig. 5.8). Small portions of the esophagus are commonly visualized (9). The esophagus appears as a tubular structure in the posteriorEbook Atlas of fetal MRI: Part 2
mediastinum. Tt is best visualized when the image acquisition coincides with the fetus swallowing a bolus of amniotic fluid or reflux occurs. The esop5MR Imaging of Fetal Thoracic AbnormalitiesDEBORAH LEVINEINTRODUCTIONA number of publications have described the benefit of magnetic resonance (MR) im Ebook Atlas of fetal MRI: Part 2 separating the abdomen from the thorax. It has low signal intensity on T?-weightcd images and is of a signal intensity slightly lower than that of the liver (14). It is most clearly seen on the coronal and sagittal images9192Atlas of Fetal MRIFigure 5.1 Normal lungs in early- to midsecond Inmesler. Ebook Atlas of fetal MRI: Part 2 Axial and coronal Tj-weighted images at 14 (a and h) and IX (c and d) weeks gestational age show the lungs (I.) and die heart (H). The pulmonary vascEbook Atlas of fetal MRI: Part 2
ulature is difficult lo assess al these early gestational ages, s. stomach.Figure 5.2 Normal lungs late second to third trimesters. Axial and sagittal5MR Imaging of Fetal Thoracic AbnormalitiesDEBORAH LEVINEINTRODUCTIONA number of publications have described the benefit of magnetic resonance (MR) im Ebook Atlas of fetal MRI: Part 2h (he lungs in Fig. 5.1. and the pulmonary vessels appear as prominent flow voids branching (arrows) from the hila. Note the descending aorta (arrowhead) anterior to (he spine. H. heart.Fetal Thorax93Figure 5.3 Chart of lung signal intensity compared to gestational age in normal lungs. Lung signal i Ebook Atlas of fetal MRI: Part 2ntensity on Ti-weighled images was graded on a live-point scale as follows: I. as bright as fluid (using either amniotic fluid or cerebrospinal fluidEbook Atlas of fetal MRI: Part 2
at a similar distance from the coil as comparison): 2. slightly less than fluid; 3. intermediate between fluid and muscle: 4. slightly greater than mu5MR Imaging of Fetal Thoracic AbnormalitiesDEBORAH LEVINEINTRODUCTIONA number of publications have described the benefit of magnetic resonance (MR) im Ebook Atlas of fetal MRI: Part 2image shows rhe pulmonary outflow tract (arrowhead), aortic outflow tract (♦). and superior vena cava (arrow).(Fig. 5.10). Al least portions of the diaphragm can be observed on most studies (15).The ThymusThe thymus is hest visualized in the third trimester when it appears as an intermediate to low Ebook Atlas of fetal MRI: Part 2signal intensity structure in the anterior mediastinum (Fig. 5.11). The normal size of the thymus in the fetus has not yet been established.Figure 5.5Ebook Atlas of fetal MRI: Part 2
Ductal arch and aortic arch. Oblique sagittal Trweighted images in two different fetuses show the ductal arch (arrow in a) arising from the anteriorl5MR Imaging of Fetal Thoracic AbnormalitiesDEBORAH LEVINEINTRODUCTIONA number of publications have described the benefit of magnetic resonance (MR) im Ebook Atlas of fetal MRI: Part 2h supply the descending aorta, located anterior to the spine.94Atlas of Fetal MRIFigure 5.6 Normal vascularity. Oblique coronal spectral spatial waler excitation sequence shows flowing blood as high signal intensity. The inferior vena cava (arrowhead), aorta (thin arrows), and superior vena eava (la Ebook Atlas of fetal MRI: Part 2rge arrow) are all well-visualized. (From Levine et al. (13)1Figure 5.7 Normal heart. Axial Tj-wcightcd image at 19 weeks gestational age (a) and Ti-wEbook Atlas of fetal MRI: Part 2
eighled image at 26 weeks gestational age (b) illustrate the heart and the interventricular septum (arrowhead). Normally images arc not cardiac gated,5MR Imaging of Fetal Thoracic AbnormalitiesDEBORAH LEVINEINTRODUCTIONA number of publications have described the benefit of magnetic resonance (MR) im Ebook Atlas of fetal MRI: Part 2 and b) Oblique coronal Trweighted images al 23 weeks gestational age show the right and left mainstem bronchi (arrows), (c) Sagittal Tj-weighted image in a different fetus at 34 weeks gestational age shows the trachea, (d) Coronal Tj-wcightcd image in a fetus with a CCAM (arrowhead) shows the carin Ebook Atlas of fetal MRI: Part 2a and mainstein bronchi (arrows).Fetal Thorax5MR Imaging of Fetal Thoracic AbnormalitiesDEBORAH LEVINEINTRODUCTIONA number of publications have described the benefit of magnetic resonance (MR) im5MR Imaging of Fetal Thoracic AbnormalitiesDEBORAH LEVINEINTRODUCTIONA number of publications have described the benefit of magnetic resonance (MR) imGọi ngay
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