Biomedical subjects

Greggory R DeVore

Publications and source records attributed to Greggory R DeVore.

9 recordsLinked to original sources

PubMed2005

Assessing fetal cardiac ventricular function.

Fetal echocardiography has been used primarily to identify fetuses with structural malformations of the heart. Evaluation of fetal ventricular function, however, has received minimal attention since the inception of fetal echocardiography in the early 1980s. This communication reviews the use of M-mode, B-mode and pulsed Doppler ultrasound to examine cardiac function. M-mode ultrasound is used to determine the size of the fetal heart, the end-diastolic and end-systolic dimensions of the ventricular chambers, and the thickness of the ventricular walls and the interventricular septum, and to measure the diameter of the mitral and tricuspid valves as well as the diameter of the aorta and pulmonary artery. B-mode evaluation of the fetal heart includes measurement of atrial and ventricular dimensions as well as dimensions of the outflow tracts. This modality is useful when M-mode measurements cannot be made due to fetal position. Once measurements of cardiac structures are obtained using either M-mode or B-mode ultrasound, pulsed Doppler recording of mitral valve, tricuspid valve, aortic valve and pulmonary artery waveforms can be used to compute cardiac output as well as stroke volume. In addition, pulsed Doppler can be used to evaluate diastolic and systolic cardiac functions by examining the components of each waveform.

Echocardiography↗

PubMed2004

Phenotypic characteristics of absent and hypoplastic nasal bones in fetuses with Down syndrome: description by 3-dimensional ultrasonography and clinical significance.

OBJECTIVE: To determine the frequency and clinical significance of bilateral and unilateral hypoplastic nasal bones for the detection of Down syndrome by 3-dimensional ultrasonography. METHODS: Thirty-seven volumes of the fetal skull from fetuses with Down syndrome and 37 from fetuses without abnormalities were analyzed by 1 investigator blinded to fetal karyotype. The maximum intensity projection algorithm was used to reconstruct nasal bones. Ossification patterns were identified in anteroposterior and profile views. Sensitivity, false-positive rates (FPRs), and likelihood ratios (LRs) for detection of Down syndrome were calculated. RESULTS: After exclusions (coronal acquisition [n = 11], hand in front of the face [n = 4], poor imaging [n = 2], incomplete follow-up [n = 2], and anomalies detected after delivery [n = 2]), 53 volumes were analyzed (26 fetuses with Down syndrome and 27 without abnormalities; median gestational age, 21 6/7 weeks [interquartile range, 19 6/7-25 2/7 weeks]). Rendered profile views revealed absent nasal bones in 18.9% (10 of 53) of the fetuses, and, among these, 90% (9 of 10) had Down syndrome (sensitivity, 34.6% [9 of 26]; FPR, 3.7% [1 of 27]; LR, 9.3 [95% confidence interval (CI), 1.3-68.7]). Three ossification patterns were identified in anteroposterior views: (1) normally developed, (2) delayed ossification, and (3) absent nasal bones. Sensitivity, FPR, and LR of absent nasal bones for detecting Down syndrome were 34.6% (9 of 26), 3.7% (1 of 27), and 9.0 (95% CI, 1.3-68.7), respectively. Sensitivity, FPR, and LR of delayed ossification for detecting Down syndrome were 42.3% (11 of 26), 22% (6 of 27), and 1.83 (95% CI, 0.8-4.4). CONCLUSIONS: Absence of nasal bones is associated with the highest risk of Down syndrome. Delayed ossification is associated with a lower risk of Down syndrome than absent nasal bones. These ossification patterns may be indistinguishable on 2-dimensional ultrasonography.

Down Syndrome↗

PubMed2004

Real-time 3-dimensional fetal echocardiography with an instantaneous volume-rendered display: early description and pictorial essay.

OBJECTIVE: Random fetal motion, rapid fetal heart rates, and cumbersome processing algorithms have limited reconstructive approaches to 3-dimensional fetal cardiac imaging. Given the recent development of real-time, instantaneous volume-rendered sonographic displays of volume data, we sought to apply this technology to fetal cardiac imaging. METHODS: We obtained 1 to 6 volume data sets on each of 30 fetal hearts referred for formal fetal echocardiography. Each volume data set was acquired over 2 to 8 seconds and stored on the system's hard drive. Rendered images were subsequently processed to optimize translucency, smoothing, and orientation and cropped to reveal "surgeon's eye views" of clinically relevant anatomic structures. Qualitative comparison was made with conventional fetal echocardiography for each subject. RESULTS: Volume-rendered displays identified all major abnormalities but failed to identify small ventricular septal defects in 2 patients. Important planes and views not visualized during the actual scans were generated with minimal processing of rendered image displays. Volume-rendered displays tended to have slightly inferior image quality compared with conventional 2-dimensional images. CONCLUSIONS: Real-time 3-dimensional echocardiography with instantaneous volume-rendered displays of the fetal heart represents a new approach to fetal cardiac imaging with tremendous clinical potential.

Adult↗

PubMed2003

The role of fetal echocardiography in genetic sonography.

Genetic sonography identifies between 60% and 93% of fetuses with trisomy 21. One of the reasons for the variation in sensitivity is because of the under-detection of congenital heart defects. Although congenital heart defects are present in 56% of second trimester fetuses and 44% of newborns with trisomy 21, most studies evaluating second-trimester fetuses at risk for trisomy 21 detect less than 10% of heart malformations. This review discusses an approach that allows the fetal sonographer to incorporate fetal echocardiography, based upon the examiner's level of skill and experience, when evaluating the fetus at risk for trisomy 21. The cardiovascular examination consists of three levels. In the Level I examination only noncardiac markers are evaluated for a detection rate of 60% and false-positive rate of 5.9%. The Level II examination incorporates the four-chamber view with non-cardiac markers. If the examiner can identify atrial and/or ventricular chamber disproportion, then the sensitivity is increased to 75%, with a false-positive rate of 6.4%. The Level III examination utilizes grayscale and color Doppler ultrasound to evaluate the fetal heart. If the examiner can identify ventricular septal defects, atrioventricular septal defects, pericardial effusion, tricuspid regurgitation, and chamber disproportion, then the sensitivity of genetic sonography increases to 91% with a false-positive rate of 14%. This review includes Likelihood Ratios for each of the ultrasound markers so that the examiner can compute the risk for trisomy 21 for an individual patient.

Adult↗

PubMed2003

Is genetic ultrasound cost-effective?

During the past 10 years, investigators have reported studies examining the potential of second-trimester genetic sonography to identify fetuses at risk for trisomy 21. The consensus among most investigators is that genetic sonography offers an alternative to universal amniocentesis in high-risk women and lowers the loss rate of normal fetuses subjected to amniocentesis because of risk factors associated with advanced maternal age or abnormal maternal-serum screening. Although there is now consensus that genetic sonography may be a useful screening tool, there has been a paucity of data regarding its cost-effectiveness. In this review, 3 studies are examined and cost-effectiveness of genetic sonography evaluated. The first study compared genetic sonography and universal amniocentesis and found that genetic sonography was cost-effective if the sensitivity is 75% or higher, resulted in a savings to the healthcare system of 9%, and decreased the loss rate of normal fetuses following amniocentesis by 87%. The second study examined the use of genetic sonography in women less than 35 years of age who underwent maternal-serum triple-marker serum screening. Women who were screen negative but who were classified as moderate risk for trisomy 21 (risk 1:191 to 1:1,000) were offered genetic sonography. Amniocentesis was offered only if the genetic sonogram was abnormal. The study demonstrated that the use of genetic sonography in this group of patients increased the detection rate of trisomy 21, was cost effective, and was a safe procedure. The third study examined the use of genetic sonography in women 35 years of age and older who declined amniocentesis following second-trimester genetic counseling. Genetic sonography was offered to this group of patients followed by amniocentesis if an abnormal ultrasound finding was present. The data were analyzed for various acceptance rates of amniocentesis by the patient when informed of the ultrasound findings. Examination of the data demonstrated this approach increased the detection rate of trisomy 21, was cost-effective, and was a safe procedure. In conclusion, genetic sonography when applied in the above clinical settings is cost-effective, results in a higher detection rate of trisomy 21, and is safe procedure.

Adult↗

PubMed2003

An 8-center study to evaluate the utility of mid-term genetic sonograms among high-risk pregnancies.

OBJECTIVE: A multicenter study was undertaken to evaluate the diagnostic efficacy of a genetic sonogram. METHODS: Eight centers provided data on 176 pregnancies complicated by fetal Down syndrome. One hundred thirty-four pregnancies were considered high risk because of advanced maternal age (> 35 years), and 42 were considered high risk for having "abnormal" triple-screen results (risk > 1:250). Each center provided fetal biometric data, information regarding the presence or absence of major structural abnormalities, and between 3 and 6 additional ultrasonographic markers for trisomy 21. The heterogeneity of our 8 independent "sensitivity estimates" was evaluated by Poisson regression, and a single combined estimate of the sensitivity was calculated. RESULTS: Of the total 176 cases of trisomy 21, 125 fetuses (71.0%) had either an abnormal long bone length (femur length, humerus length, or both), a major structural abnormality, or a Down syndrome marker. The combined diagnostic sensitivity was 71.6%, with a range of 63.6% (7 of 11) to 80% (8 of 10). Five centers had sensitivity estimates falling between 64% and 76%. The sensitivity of individual markers varied between 3% (sandal gap) and 46.5% (nuchal skin fold thickness). A condensed regimen of nuchal skin fold thickness, femur length, and a standard anatomic survey would screen in 56.8% of fetuses with Down syndrome. CONCLUSIONS: This 8-center study that included many fetuses with Down syndrome validates the concept that the genetic sonogram can be used to better adjust the Down syndrome risk for high-risk patients.

Biometry↗

PubMed2003

Nasal bone evaluation in fetuses with Down syndrome during the second and third trimesters of pregnancy.

OBJECTIVE: This study examined the use of three-dimensional ultrasonography for evaluating the fetal nasal bone, as a sonographic marker of Down syndrome, during the second and early third trimesters of pregnancy. METHODS: Forty fetuses, including 20 with trisomy 21, were scanned once by three-dimensional ultrasonography. A midline sagittal view of the facial profile was used to analyze the volume data. Independent examiners reviewed blinded and randomly allocated volume data sets for the nasal bone. Interobserver reliability was evaluated for the sonographic presence or absence of the nasal bone. Logistic regression determined the contribution of this parameter to the presence of Down syndrome. RESULTS: Both examiners showed substantial agreement in scoring whether the nasal bone was visualized by three-dimensional ultrasonography (P < .001). They identified 40% to 45% of fetuses with abnormalities using the absence of the nasal bone as a sonographic marker. However, a substantial number of fetuses with abnormalities were also found to have a nasal bone present. The nasal bone was visualized in 80% to 90% of fetuses without abnormalities. CONCLUSIONS: Three-dimensional ultrasonography can be used to evaluate the fetal nasal bone with substantial interobserver agreement during the second and early third trimesters of pregnancy. A nonvisualized nasal bone identified 40% to 45% of fetuses with Down syndrome in this study.

Down Syndrome↗

PubMed2003

Genetic sonography: an option for women of advanced maternal age with negative triple-marker maternal serum screening results.

OBJECTIVE: To determine whether offering genetic sonography to patients 35 years of age and older with negative maternal serum triple-marker screening results will result in an increase in the detection rate of trisomy 21. METHODS: The detection rate of trisomy 21 was determined in women 35 years of age and older whose pregnancies were managed according to the following 3 policies: policy I, universal amniocentesis; policy II, maternal serum triple-marker screening followed by amniocentesis only in high-risk women (risk >1:190); and policy III, genetic sonography in women with negative maternal serum screening results (policy II). Policy III included the offering of genetic amniocentesis to patients with abnormal genetic sonographic findings. The rate of acceptance of genetic amniocentesis was modeled, as was the sensitivity (50%-90%) and false-positive rate (5%-25%) of genetic sonography. RESULTS: The number of fetuses expected to have trisomy 21 was 784. For patients evaluated under policy II, 86.3% of fetuses with trisomy 21 were detected. On the basis of the detection rate for trisomy 21 of policy II, the addition of fetuses with trisomy 21 identified under policy III was significantly (P < .01) increased (93.2% to 98.6%) for genetic sonographic sensitivities ranging between 50% and 90%. CONCLUSIONS: A policy of offering genetic sonography followed by amniocentesis to patients 35 years of age and older who originally had triple-marker maternal serum screening findings that were negative for the diagnosis of trisomy 21 results in a higher overall detection rate of trisomy 21.

Adult↗

PubMed2002

Genetic sonography: a cost-effective method for evaluating women 35 years and older who decline genetic amniocentesis.

OBJECTIVE: To determine whether offering genetic sonography to patients who decline invasive testing can increase the detection rate of trisomy 21 and is cost-effective. METHODS: The detection rate of trisomy 21, the number of pregnancy losses after amniocentesis, and the cost of detecting a single fetus with trisomy 21 were determined in women 35 years and older managed according to the following 3 policies: (1) universal amniocentesis, (2) genetic counseling for maternal age-associated risks for trisomy 21 followed by amniocentesis in patients who elected it, and (3) genetic counseling followed by genetic sonography in patients who originally declined genetic amniocentesis. RESULT: From a population of 40,143 women 35 years and older, the expected number of trisomy 21 fetuses was 349. After genetic counseling, 32% of patients declined invasive testing, resulting in detection of 70% of fetuses with trisomy 21. For universal amniocentesis, the cost to detect 1 fetus with trisomy 21 was $138,036. For the 32% who declined invasive testing after genetic counseling and underwent genetic sonography, the cost to detect a single fetus with trisomy 21 was a function of sensitivity and the screen-positive rate. For screen-positive rates between 5% and 25%, genetic sonography resulted in a cost savings between 14.3% and 18.8% when compared with universal invasive testing and resulted in a considerable increase in detection of fetuses with trisomy 21 (77% to 97%). CONCLUSIONS: A policy of offering genetic sonography followed by amniocentesis to patients 35 years and older who originally decline invasive testing for the diagnosis of trisomy 21 is cost-effective and results in a higher overall detection rate for trisomy 21 without an increased risk of pregnancy loss.

Adult↗