Obstetric and gynecologic ultrasound curriculum and competency assessment in residency training programs: consensus report.

Ultrasound imaging has become integral to the practice of obstetrics and gynecology. With increasing educational demands and limited hours in residency programs, dedicated time for training and achieving competency in ultrasound has diminished substantially. The American Institute of Ultrasound in Medicine assembled a multi-Society Task Force to develop a consensus-based, standardized curriculum and competency assessment tools for obstetric and gynecologic ultrasound training in residency programs. The curriculum and competency-assessment tools were developed based on existing national and international guidelines for the performance of obstetric and gynecologic ultrasound examinations and thus are intended to represent the minimum requirement for such training. By expert consensus, the curriculum was developed for each year of training, criteria for each competency assessment image were generated, the pass score was established at or close to 75% for each, and obtaining a set of five ultrasound images with pass score in each was deemed necessary for attaining each competency. Given the current lack of substantial data on competency assessment in ultrasound training, the Task Force expects that the criteria set forth in this document will evolve with time. The Task Force also encourages use of ultrasound simulation in residency training and expects that simulation will play a significant part in the curriculum and the competency-assessment process. Incorporating this training curriculum and the competency-assessment tools may promote consistency in training and competency assessment, thus enhancing the performance and diagnostic accuracy of ultrasound examination in obstetrics and gynecology. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Case report: moderate hemolytic disease of the newborn due to anti-G.

Views expressed in this article are those of the author and do not reflect the official policy or position of the Department of the Navy, Department of Defense, or U.S. Government. The only previously published case of anti-G in a pregnant woman indicated that anti-G alone caused little, if any, fetal or neonatal hemolysis. This report describes an affected fetus with amnionitic fluid OD 450 absorbance values in the moderate zone of the Liley prediction graph who required prolonged phototherapy after birth until day of life 20. Anti-G was identified and anti-C and -D excluded in the mother's serum. In contrast to the previous report, this report shows anti-G alone can cause moderate HDN and that fetal monitoring and treatment may be necessary.

Pathogenesis of acardiac twinning: clues from an almost acardiac twin.

OBJECTIVE: To search for clues to the pathogenesis of acardiac twinning. METHODS: We examined a case of monoamniotic twins in which twin A's only sonographic abnormality was a dilated, tortuous ductus venosus. Twin B also had this abnormality as well as multiple other anomalies that included enormous hydrops and a severely hypoplastic heart. Following termination of pregnancy, autopsy was performed. RESULTS: Postmortem examination of the placenta confirmed monochorionic, monoamniotic placentation with two adjacent trivascular cords. Autopsy confirmed the sonographic findings of enormous hydrops in twin B with a severely malformed, almost nonexistent heart. In addition, the liver was small and was represented by a cyst-like structure with thin rims of congested parenchyma surrounding large vascular spaces. CONCLUSION: We believe the sequence of events in this case was early twin-to-twin transfusion resulting in a dysfunctional heart in twin B. This enabled a twin reversal arterial perfusion sequence with further deterioration of twin B's heart and extreme congestion of deoxygenated blood exiting the heart into the inferior vena cava and ductus venosus. This case supports the concept that circulatory reversal in the face of an initially functioning heart may lead to congestion, tissue hypoxia and secondary organ atrophy.

Early second trimester prenatal diagnosis of Neu-Laxova syndrome.

Neu-Laxova is a rare, uniformly lethal, autosomal recessive condition with characteristic limb posturing, facial dysmorphic features, and central nervous system abnormalities. Forty-two cases of Neu-Laxova syndrome have been reported, with only four of these diagnosed prenatally. Three of the four cases were diagnosed at or after 32 weeks' gestation. The fourth case was diagnosed at 22 weeks' gestation in a patient who was followed with serial ultrasound studies due to having a prior affected child. At 19 weeks' gestation, we present the earliest reported prenatal diagnosis of Neu-Laxova syndrome in a primigravida with a non-informative family history.

Non-mosaic trisomy 20 presenting at 21 weeks' gestation as a thoraco-abdominal mass.

Non-mosaic trisomy 20 is rare in fetuses surviving beyond the first trimester. We report a case of a fetus with non-mosaic trisomy 20 in amniotic fluid cultures obtained during the prenatal evaluation of an unusual thoraco-abdominal mass which was found at autopsy to be pulmonary sequestration. Gross inspection and autopsy of the fetus revealed multiple anomalies.

Optical absorption modeling of thermal infrared detectors by use of the finite-difference time-domain method.

The optical absorption of thin-film thermal infrared detectors was calculated as a function of wavelength, pixel size, and area fill factor by use of the finite-difference time-domain (FDTD) method. The results indicate that smaller pixels absorb a significantly higher percentage of incident energy than larger pixels with the same fill factor. A polynomial approximation to the FDTD results was derived for use in system models.

Performance comparison of rectangular (four-point) and diagonal (two-point) dither in undersampled infrared focal plane array imagers.

Undersampled staring array imagers exhibit sampling artifacts. Dither is a mechanical means of raising the spatial sampling rate without increasing the number of detectors on the focal plane array. Diagonal (two-point or slant-path) dither is easier to implement than rectangular (four-point or bowtie) dither. Also, diagonal dither generates half the data rate of rectangular dither. However, diagonal dither does not sample the image as effectively as rectangular dither. The cost and complexity advantages of diagonal dither must be traded against the expectation of reduced performance. We discuss analytical and empirical predictions of the performance difference between diagonal and rectangular dither. To compare diagonal and rectangular dither empirically, a target identification (ID) experiment was performed. The visual task involved target ID among a set of 12 tactical vehicles. High-resolution (close-up) images of the targets were blurred and downsampled to produce images representative of those seen with a 320 x 240 pixel staring array sensor. The nondithered imagery was poorly sampled, and the imagery with rectangular dither was adequately sampled. The experiment compared the static target ID performance of nondithered, diagonally dithered, and rectangularly dithered sensors. Analytical and empirical results are described.

Isolated bilateral anophthalmia in a girl with an apparently balanced de novo translocation: 46,XX,t(3;11)(q27;p11.2).

Primary anophthalmos is a heterogeneous condition. In its nonsyndromal form, it is usually considered an autosomal recessive trait. However, other causes such as chromosomal abnormalities and prenatal insults need to be considered. We report on a unique reciprocal translocation 46,XX,t(3;11)(q27;p11.2) in a baby with isolated anophthalmos. Both Chitayat et al. [1996] and Alvarez Arratia et al. [1984] have reported on cases of terminal deletion of the long arm of chromosome 3. In each case the child had multiple anomalies including microphthalmia or anophthalmia. Because our patient appears to have no other anomalies, this break point may indicate that a genetic locus for eye formation exists at chromosome site 3q27. Published 1999 Wiley-Liss, Inc.

Equivalent blur as a function of spurious response of a sampled imaging system: application to character recognition.

Image sampling effects have been variously quantified as aliased signal, spatial signal, and spatial noise. However, a relationship between these characteristics and human object recognition has not been established in a coherent, mathematical form. We present a heuristic study that characterizes the performance degradation that is due to the spurious response of a sampled imaging system as an effective increase in system blur. A character recognition experiment was performed in which 20 observers responded to 3500 character pairs of blur and sample spacing. A baseline was created where the probability of character recognition was determined as a function of blur without sampling. The sampled characters were then compared with this baseline so that the effect of sampling on character recognition could be determined. Finally, an increase in blur was established as a function of spurious response, which describes the overall effect of sampling on observer character recognition.

Sensor performance conversions for infrared target acquisition and intelligence-surveillance-reconnaissance imaging sensors.

Target acquisition infrared imaging sensors are characterized by their minimum resolvable temperature parameter that is translated to the probability of identification (Pid) performance estimate for a given target. Intelligence-surveillance-reconnaissance (ISR) sensors are characterized by the general image quality equation to give a national imagery interpretability rating scale (NIIRS) performance estimate. Sensors, such as those on Predator and Global Hawk, will soon be used for both ISR and target acquisition purposes. We present a performance conversion that includes both sensor resolution and sensitivity. We also provide the first empirical results to our knowledge ever to be presented that relate NIIRS and Pid for a given set of targets.

Delaying surgery for thyroid cancer in pregnancy. A case report.

BACKGROUND: Management of thyroid cancer in pregnancy is controversial, as evidenced by disagreement in recommendations cited in leading obstetrics textbooks. Most thyroid carcinomas are well differentiated and pursue an indolent course. Many physicians recommend delay in surgical therapy until after delivery because of operative morbidity. CASE: A 27-year-old primigravida was found to have a solitary thyroid nodule at her initial obstetrics appointment. Fine needle aspiration was consistent with papillary carcinoma. Although detected at 8 weeks' estimated gestational age (EGA), the decision was made to defer surgical therapy until postpartum. The patient was referred to a tertiary care facility at 24 weeks' EGA secondary to rapid growth of the nodule. Surgery performed at that time revealed invasive disease. CONCLUSION: Review of the literature suggests that delay in definitive therapy stems from early reports of fetal loss related to surgery, but contemporary data suggest that the risk of fetal loss related to surgery is minimal.

Long-range radiometer measurements with a close-range reference.

A correction procedure is described for the use of a radiometer for transmission measurements. In this application a blackbody is presented to the radiometer at close range as a field calibration. The radiometer is then used to measure atmospheric attenuation by looking at a blackbody source at a much longer range. Three factors that limit the accuracy of this approach to transmission measurements are identified, and a correction factor is derived. The theoretical correction factor is verified by measurements. Excellent agreement between the measurements and the theory suggests that the major factors limiting this technique have been identified and properly accounted for.

Comparison of continuous and discrete frequency-versus-radius frequency-modulated reticles.

We present a general expression for the transmission function of the discrete frequency-versus-radius reticle and compare such a reticle with the more common continuous reticle. A discrete form of the frequency-versus-radius reticle has an integer number of chopping cycles on a single radius. The discreteform limits the resolution of the reticle in the radial direction, but this limit is not severe for small-target images. However, since no phase reversal occurs, electronic processing is simplified.

Effect of phasing-sector angular extent in FM reticles.

A technique is presented for increasing the useful power of the FM modulation signal from a spinning FM reticle with a phasing sector. Spinning FM reticles often determine a target location by using a combination of a phasing sector to establish the angular target location and a radial frequency variation to establish the radial target location. Typically, the phasing sector of this reticle type consists of a semicircular transmissive sector with the other semicircular sector which provides FM modulation. The power of the FM modulation signal is increased by matching the phased-sector geometry to the size that corresponds to the period of the modulation frequency. This type of reticle is compared and contrasted with the more typical semicircular phasing-sector reticle in both the time and frequency domains.

Parameters of spinning FM reticles.

The literature describes tracking devices that allow a single detector coupled to a spinning FM reticle to determine target location. The spinning FM reticles presented were limited to single parameter reticles of frequency vs angle, frequency vs radius, or phase. This study presents these parameters with their capabilities and limitations and shows that multiple parameters can be integrated into a single reticle. Also, a general equation is developed that describes any FM reticle of the spinning type.

Parameters of spinning AM reticles.

A new method of obtaining amplitude modulation (AM) for determining target location with spinning reticles is presented. The method is based on the use of graded transmission capabilities. The AM spinning reticles previously presented were functions of three parameters: amplitude vs angle, amplitude vs radius, and phase. This paper presents these parameters along with their capabilities and limitations and shows that multiple parameters can be integrated into a single reticle. It is also shown that AM parameters can be combined with FM parameters in a single reticle. Also, a general equation is developed that relates the AM parameters to a reticle transmission equation.