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Volumetric Growth of the Liver in the Human Fetus: An Anatomical, Hydrostatic, and Statistical Study. BIOMED RESEARCH INTERNATIONAL 2015; 2015:858162. [PMID: 26413551 PMCID: PMC4564626 DOI: 10.1155/2015/858162] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Revised: 03/30/2015] [Accepted: 04/06/2015] [Indexed: 02/03/2023]
Abstract
Using anatomical, hydrostatic, and statistical methods, liver volumes were assessed in 69 human fetuses of both sexes aged 18-30 weeks. No sex differences were found. The median of liver volume achieved by hydrostatic measurements increased from 6.57 cm(3) at 18-21 weeks through 14.36 cm(3) at 22-25 weeks to 20.77 cm(3) at 26-30 weeks, according to the following regression: y = -26.95 + 1.74 × age ± Z × (-3.15 + 0.27 × age). The median of liver volume calculated indirectly according to the formula liver volume = 0.55 × liver length × liver transverse diameter × liver sagittal diameter increased from 12.41 cm(3) at 18-21 weeks through 28.21 cm(3) at 22-25 weeks to 49.69 cm(3) at 26-30 weeks. There was a strong relationship (r = 0.91, p < 0.001) between the liver volumes achieved by hydrostatic (x) and indirect (y) methods, expressed by y = -0.05 + 2.16x ± 7.26. The liver volume should be calculated as follows liver volume = 0.26 × liver length × liver transverse diameter × liver sagittal diameter. The age-specific liver volumes are of great relevance in the evaluation of the normal hepatic growth and the early diagnosis of fetal micro- and macrosomias.
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Andescavage NN, DuPlessis A, Limperopoulos C. Advanced MR imaging of the placenta: Exploring the in utero placenta-brain connection. Semin Perinatol 2015; 39:113-23. [PMID: 25765905 PMCID: PMC4409865 DOI: 10.1053/j.semperi.2015.01.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The placenta is a vital organ necessary for the healthy neurodevelopment of the fetus. Despite the known associations between placental dysfunction and neurologic impairment, there is a paucity of tools available to reliably assess in vivo placental health and function. Existing clinical tools for placental assessment remain insensitive in predicting and evaluating placental well-being. Advanced MRI techniques hold significant promise for the dynamic, non-invasive, real-time assessment of placental health and identification of early placental-based disorders. In this review, we summarize the available clinical tools for placental assessment, including ultrasound, Doppler, and conventional MRI. We then explore the emerging role of advanced placental MR imaging techniques for supporting the developing fetus and appraise the strengths and limitations of quantitative MRI in identifying early markers of placental dysfunction for improved pregnancy monitoring and fetal outcomes.
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Affiliation(s)
- Nickie Niforatos Andescavage
- Division of Neonatology, Children’s National Health System, 111
Michigan Ave. NW, Washington, DC 20010,Fetal & Transitional Medicine, Children’s National Health
System, 111 Michigan Ave. NW, Washington, DC 20010,Department of Pediatrics, George Washington University School of Medicine,
2300 Eye St. NW, Washington, DC 20037
| | - Adre DuPlessis
- Fetal & Transitional Medicine, Children’s National Health
System, 111 Michigan Ave. NW, Washington, DC 20010,Diagnostic Imaging & Radiology, Children’s National Health
System, 111 Michigan Ave. NW, Washington, DC 20010,Department of Pediatrics, George Washington University School of Medicine,
2300 Eye St. NW, Washington, DC 20037
| | - Catherine Limperopoulos
- Division of Neonatology, Children's National Health System, 111 Michigan Ave. NW, Washington, DC 20010; Division of Fetal and Transitional Medicine, Children's National Health System, 111 Michigan Ave. NW, Washington, DC 20010; Department of Pediatrics, George Washington University School of Medicine, 2300 Eye St. NW, Washington, DC 20037; Division of Diagnostic Imaging and Radiology, Children's National Health System, 111 Michigan Ave. NW, Washington, DC 20010; Division of Radiology, George Washington University School of Medicine, 2300 Eye St. NW, Washington, DC 20037.
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Abstract
Fetal MRI is becoming an increasingly powerful imaging tool for studying brain development in vivo. Until recently, the application of advanced magnetic resonance imaging techniques was limited by motion in the nonsedated fetus. Extensive research efforts currently underway are focusing on the development of dedicated magnetic resonance imaging sequences and sophisticated postprocessing techniques that are revolutionizing our ability to study the healthy and compromised fetus. The ongoing refinement of these magnetic resonance imaging techniques will undoubtedly lead to the development of cornerstone biomarkers that will provide healthcare caregivers with vital, and currently lacking, information upon which to counsel parents effectively, and base rational decisions regarding the timing and type of novel medical and surgical interventions currently on the horizon.
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Jiang S, Xue H, Glover A, Rutherford M, Rueckert D, Hajnal JV. MRI of moving subjects using multislice snapshot images with volume reconstruction (SVR): application to fetal, neonatal, and adult brain studies. IEEE TRANSACTIONS ON MEDICAL IMAGING 2007; 26:967-80. [PMID: 17649910 DOI: 10.1109/tmi.2007.895456] [Citation(s) in RCA: 125] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Motion degrades magnetic resonance (MR) images and prevents acquisition of self-consistent and high-quality volume images. A novel methodology, Snapshot magnetic resonance imaging (MRI) with Volume Reconstruction (SVR) has been developed for imaging moving subjects at high resolution and high signal-to-noise ratio (SNR). The method combines registered 2-D slices from sequential dynamic single-shot scans. The SVR approach requires that the anatomy in question is not changing shape or size and is moving at a rate that allows snapshot images to be acquired. After imaging the target volume repeatedly to guarantee sufficient sampling every where, a robust slice-to-volume registration method has been implemented that achieves alignment of each slice within 0.3 mm in the examples tested. Multilevel scattered interpolation has been used to obtain high-fidelity reconstruction with root-mean-square (rms) error that is less than the noise level in the images. The SVR method has been performed successfully for brain studies on subjects that cannot stay still, and in some cases were moving substantially during scanning. For example, awake neonates, deliberately moved adults and, especially, on fetuses, for which no conventional high-resolution 3-D method is currently available. Fine structure of the in-utero fetal brain is clearly revealed for the first time and substantial SNR improvement is realized by having many individually acquired slices contribute to each voxel in the reconstructed image.
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Affiliation(s)
- Shuzhou Jiang
- Imaging Sciences Department, MRC Clinical Sciences Centre, Hammersmith Hospital, Imperial College London, UK.
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Prayer D, Brugger PC. Investigation of normal organ development with fetal MRI. Eur Radiol 2007; 17:2458-71. [PMID: 17342486 DOI: 10.1007/s00330-007-0604-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2006] [Revised: 12/15/2006] [Accepted: 01/22/2007] [Indexed: 01/28/2023]
Abstract
The understanding of the presentation of normal organ development on fetal MRI forms the basis for recognition of pathological states. During the second and third trimesters, maturational processes include changes in size, shape and signal intensities of organs. Visualization of these developmental processes requires tailored MR protocols. Further prerequisites for recognition of normal maturational states are unequivocal intrauterine orientation with respect to left and right body halves, fetal proportions, and knowledge about the MR presentation of extrafetal/intrauterine organs. Emphasis is laid on the demonstration of normal MR appearance of organs that are frequently involved in malformation syndromes. In addition, examples of time-dependent contrast enhancement of intrauterine structures are given.
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Affiliation(s)
- Daniela Prayer
- Department of Radiology, Medical University of Vienna, Waehringerguertel 18-20, 1090, Vienna, Austria.
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Brugger PC, Stuhr F, Lindner C, Prayer D. Methods of fetal MR: beyond T2-weighted imaging. Eur J Radiol 2006; 57:172-81. [PMID: 16377112 DOI: 10.1016/j.ejrad.2005.11.017] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2005] [Revised: 11/14/2005] [Accepted: 11/16/2005] [Indexed: 12/21/2022]
Abstract
The present work reviews the basic methods of performing fetal magnetic resonance imaging (MRI). Since fetal MRI differs in many respects from a postnatal study, several factors have to be taken into account to achieve satisfying image quality. Image quality depends on adequate positioning of the pregnant woman in the magnet, use of appropriate coils and the selection of sequences. Ultrafast T2-weighted sequences are regarded as the mainstay of fetal MR-imaging. However, additional sequences, such as T1-weighted images, diffusion-weighted images, echoplanar imaging may provide further information, especially in extra- central-nervous system regions of the fetal body.
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Affiliation(s)
- Peter C Brugger
- Center of Anatomy and Cell Biology, Integrative Morphology Group, Medical University of Vienna, Waehringerstrasse 13, 1090 Vienna, Austria.
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Brugger PC, Prayer D. Fetal abdominal magnetic resonance imaging. Eur J Radiol 2006; 57:278-93. [PMID: 16388926 DOI: 10.1016/j.ejrad.2005.11.030] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2005] [Revised: 11/14/2005] [Accepted: 11/16/2005] [Indexed: 11/21/2022]
Abstract
This review deals with the in vivo magnetic resonance imaging (MRI) appearance of the human fetal abdomen. Imaging findings are correlated with current knowledge of human fetal anatomy and physiology, which are crucial to understand and interpret fetal abdominal MRI scans. As fetal MRI covers a period of more than 20 weeks, which is characterized not only by organ growth, but also by changes and maturation of organ function, a different MR appearance of the fetal abdomen results. This not only applies to the fetal intestines, but also to the fetal liver, spleen, and adrenal glands. Choosing the appropriate sequences, various aspects of age-related and organ-specific function can be visualized with fetal MRI, as these are mirrored by changes in signal intensities. Knowledge of normal development is essential to delineate normal from pathological findings in the respective developmental stages.
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Affiliation(s)
- Peter C Brugger
- Center of Anatomy and Cell Biology, Integrative Morphology Group, Medical University of Vienna, Waehringerstrasse 13, 1090 Vienna, Austria.
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Abstract
Since the introduction of fetal magnetic resonance imaging (MRI) into prenatal diagnostics, advances in coil technology and development of ultrafast sequences have further enhanced this technique. At present numerous sequences are available to visualize the whole fetus with high resolution and image quality, even in late stages of pregnancy. Taking into consideration the special circumstances of examination and adjusting sequence parameters to gestational age, fetal anatomy can be accurately depicted. The variety of sequences also allows further characterization of fetal tissues and pathologies. Fetal MRI not only supplies additional information to routine ultrasound studies, but also reveals fetal morphology and pathology in a way hitherto not possible.
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Affiliation(s)
- P C Brugger
- Arbeitsgruppe Integrative Morphologie, Zentrum für Anatomie und Zellbiologie, Medizinische Universität Wien.
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Abstract
Ultrasound is the imaging modality of choice for pregnant patients. However, MRI is increasingly utilized in patients in whom the sonographic diagnosis is unclear. These include maternal conditions unique to pregnancy such as ectopic pregnancy, placenta accreta, and uterine dehiscence. MRI is also being increasingly utilized in the assessment of abdominopelvic pain in pregnancy, in particular in assessment for appendicitis. Fetal MRI is performed to assess central nervous system (CNS) abnormalities and patients who are considering fetal surgery for conditions such as neural tube defects, congenital diaphragmatic hernia, and masses that obstruct the airway. In the future, functional MRI and fetal volumetry may provide additional information that can aid in our care of complicated pregnancies.
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Affiliation(s)
- Deborah Levine
- Department of Radiology, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA.
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