Related Experiment Video
Updated: May 11, 2026
09:52
Accurate and Simple Evaluation of Vascular Anastomoses in Monochorionic Placenta using Colored Dye
Published on: September 5, 2011
26.7K
Advances in Imaging for Placenta Accreta Spectrum Disorder
Jerri Waller1, Alireza Shamshirsaz, Alfred Abuhamad
1Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, Eastern Virginia Medical School, and Macon and Joan Brock Virginia Health Sciences at Old Dominion University, Norfolk, Virginia; and Harvard Medical School, Boston's Children Hospital, Boston, Massachusetts.
Obstetrics and Gynecology
|April 10, 2025
Summary
Placenta accreta spectrum (PAS) is a serious pregnancy complication linked to abnormal placental development and rising cesarean deliveries. Early prenatal diagnosis using advanced imaging is crucial for managing risks and planning surgical interventions.
Area of Science:
- Obstetrics and Gynecology
- Maternal-Fetal Medicine
- Radiology
Background:
- Placenta accreta spectrum (PAS) arises from abnormal placental trophoblast development, leading to uterine tissue invasion.
- The incidence of PAS is increasing, largely due to a higher rate of cesarean deliveries.
- PAS diagnosis is associated with substantial risks of maternal morbidity and mortality, including hemorrhage and surgical complications.
Purpose of the Study:
- To highlight the critical importance of accurate prenatal diagnosis for Placenta Accreta Spectrum (PAS).
- To emphasize the need for optimized resource allocation and surgical planning before delivery in PAS cases.
- To review advancements in imaging modalities for improving antenatal diagnosis of PAS.
Main Methods:
- Review of advances in diagnostic imaging techniques for Placenta Accreta Spectrum (PAS).
- Focus on ultrasonography, magnetic resonance imaging (MRI), and computed tomography (CT) in antenatal diagnosis.
- Discussion of how these imaging modalities aid in surgical planning and resource management.
Main Results:
- Advanced imaging techniques like ultrasonography, MRI, and CT have significantly improved the accuracy of prenatal PAS diagnosis.
- Improved diagnostic accuracy facilitates better preparation for potential complications such as maternal hemorrhage.
- Enhanced prenatal detection allows for optimized surgical planning and allocation of critical care resources.
Conclusions:
- Accurate prenatal diagnosis of Placenta Accreta Spectrum (PAS) is essential for mitigating maternal risks.
- Technological advancements in ultrasonography, MRI, and CT are pivotal in achieving reliable antenatal detection of PAS.
- Effective prenatal diagnosis enables optimized management strategies, improving outcomes for both mother and neonate.
Related Concept Videos
00:56Doppler Effect - I
The Doppler effect and Doppler shift were named after the Austrian physicist and mathematician Christian Johann Doppler in 1842, who conducted experiments with both moving sources and moving observers. Consider an observer standing on a street corner, observing an ambulance with a siren sound passing by at a constant speed. The observer experiences two characteristic changes in the sound of the siren. Initially, the sound increases in loudness as the ambulance approaches and decreases in...
01:05Doppler Effect - II
The Doppler effect has several practical, real-world applications. For instance, meteorologists use Doppler radars to interpret weather events based on the Doppler effect. Typically, a transmitter emits radio waves at a specific frequency toward the sky from a weather station. The radio waves bounce off the clouds and precipitation and travel back to the weather station. The radio frequency of the waves reflected back to the station appears to decrease if the clouds or precipitation are moving...
01:03IR Frequency Region: Fingerprint Region
IR spectra are divided into two main regions: the diagnostic region and the fingerprint region. The diagnostic region of the spectrum lies above 1500 cm−1. The absorptions resulting from single-bond vibrations of the N–H, C–H, and O–H stretch at higher wavenumbers and appear on the left side of the spectrum. The stretching absorptions of the C≡C and C≡N occur between 2100–2300 cm−1. In contrast, those arising from stretching absorptions of the C=O, C=N, and C=C occur between 1600–1850 cm−1.
The...
The...
01:05Difference from Background: Limit of Detection
The limit of detection (LOD) is the smallest amount of analyte that can be distinguished from the background noise. The LOD value corresponds to the concentration at which the analyte signal is three times larger than the standard deviation of the blank signal. Below this value, the analyte signal cannot be differentiated from the background noise. It is calculated by dividing the calibration slope by 3 times the standard deviation of the blank signals.
The LOD indicates the presence or absence...
The LOD indicates the presence or absence...
01:11Continuous -time Fourier Transform
The Fourier series is instrumental in representing periodic functions, offering a powerful method to decompose such functions into a sum of sinusoids. This technique, however, necessitates modification when applied to nonperiodic functions. Consider a pulse-train waveform consisting of a series of rectangular pulses. When these pulses have a finite period, they can be accurately represented by a Fourier series. Yet, as the period approaches infinity, resulting in a single, isolated pulse, the...
01:18Aliasing
Accurate signal sampling and reconstruction are crucial in various signal-processing applications. A time-domain signal's spectrum can be revealed using its Fourier transform. When this signal is sampled at a specific frequency, it results in multiple scaled replicas of the original spectrum in the frequency domain. The spacing of these replicas is determined by the sampling frequency.
If the sampling frequency is below the Nyquist rate, these replicas overlap, preventing the original signal...
If the sampling frequency is below the Nyquist rate, these replicas overlap, preventing the original signal...