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Biomedical subjects

C B Benson

Publications and source records attributed to C B Benson.

At least 37 records · Page 2Linked to original sources
PubMed1998

Benign and malignant ovarian masses: selection of the most discriminating gray-scale and Doppler sonographic features.

PURPOSE: To determine the gray-scale and Doppler sonographic features that best enable discrimination between malignant and benign ovarian masses and develop a scoring system for accurate diagnosis with these features. MATERIALS AND METHODS: Gray-scale and Doppler sonographic features of 211 adnexal masses were correlated with the final diagnosis; the most discriminating features for malignancy were selected with stepwise logistic regression. RESULTS: Twenty-eight masses were malignant and 183 benign. All masses with a markedly hyperechoic solid component or no solid component were benign. For masses with a nonhyperechoic solid component, additional features that allowed statistically significant discrimination of benignity from malignancy were, in decreasing order of importance, (a) location of flow at conventional color Doppler imaging, (b) amount of free intraperitoneal fluid, and (c) presence and thickness of septations. A scoring formula that made use of values based on the logistic regression equation had an area under the receiver operating characteristic curve of 0.98 +/- 0.01. The cutoff score with the highest accuracy had a sensitivity of 93% and specificity of 93%. CONCLUSION: A solid component is the most statistically significant predictor of a malignant ovarian mass. A multiparameter scoring system that uses three gray-scale and one Doppler feature, developed by means of stepwise logistic regression, has high sensitivity and specificity for predicting malignancy.

Adolescent↗
PubMed1998

Sonographic evaluation of the placental cord insertion site.

OBJECTIVE: Velamentous and marginal umbilical cords are uncommon abnormalities of placental cord insertion that can entail significant fetal risk. We undertook this investigation to assess the ability of prenatal sonography to reveal abnormal insertions of the umbilical cord into the placenta. SUBJECTS AND METHODS: Forty-six patients had both prenatal sonographic evaluation of the placental cord insertion site and postnatal pathologic examination. Distance from the insertion site to the nearest placental edge was categorized by sonography and pathology as normal if greater than 1 cm and abnormal if less than or equal to 1 cm. Sonographic and pathologic findings were compared. RESULTS: Thirty-eight singleton and eight twin pregnancies, for a total of 54 cord insertions, were studied. Of the 43 sonographically normal insertions, 38 had normal pathologic findings, and the remaining five insertions had abnormal pathologic findings (all marginal cord insertions). All 11 insertions that showed abnormality on sonography were abnormal on pathologic examination (seven marginal and four velamentous insertions). Sonography was able to reveal a difference between the two types of abnormal insertions in only a single patient, in whom the cord insertion changed from marginal to velamentous during a 7-week interval. Sonography had an overall sensitivity of 69% (11/16), a specificity of 100% (38/38), and an accuracy of 91% (49/54) for revealing abnormal placental cord insertion sites. CONCLUSION: Targeted sonographic examination of the placental site of umbilical cord insertion will reveal abnormal placental cord insertions, although distinguishing the specific type of abnormal insertion may require the use of color Doppler imaging.

Chorion↗
PubMed1998

Frequency and nature of structural anomalies in fetuses with single umbilical arteries.

Published studies differ concerning the rate of anomalies occurring in the presence of a single umbilical artery and the significance of the single umbilical artery as an isolated sonographic finding. We assessed the frequency, nature, and sonographic detection of structural anomalies in fetuses with a single umbilical artery. We identified all cases in which prenatal sonography diagnosed a single umbilical artery. Cases were excluded if postnatal physical or pathologic examination demonstrated a three-vessel cord, yielding a study population of 167 cases. For each case, we recorded the gestational age at diagnosis of single umbilical artery and the findings of the sonographic fetal anatomic survey. We recorded postnatal clinical and pathologic information when available. Gestational age at time of diagnosis ranged from 16.8 to 41.1 weeks (mean, 29.2 +/- 6.5 weeks). Twenty of the 167 fetuses (12%) were twins, and the remainder were singletons. Among 118 cases with postnatal information, 37 (31%) had structural abnormalities, often involving multiple organs. The most common organ systems involved were the heart (19 cases) and the gastrointestinal (14 cases) and central nervous systems (nine cases). Five of the anomalous fetuses had abnormal karyotypes. The sonographic survey was abnormal in 31 of the 37 anomalous fetuses (84%). Among 85 cases with apparently isolated single umbilical artery at sonography and known fetal outcome, six (7%) proved to be anomalous at birth. We had two sonographic false-positive results (mild hydronephrosis, suspected skeletal dysplasia). In summary, approximately one third of fetuses with single umbilical artery have structural anomalies, most often cardiac. Even when the single umbilical artery is an apparently isolated sonographic finding, the likelihood that the neonate will prove to have structural anomalies is considerable (7% in our series).

Cardiovascular Abnormalities↗
PubMed1998

"Appearing twin": undercounting of multiple gestations on early first trimester sonograms.

An important role of first trimester sonography is to determine whether a pregnancy is a singleton, twin, or higher order multiple gestation. We assessed how frequently sonography at 5.0-5.9 weeks undercounts multiple gestations. We identified all pregnancies at our institution since 1988 in which (1) an initial sonogram obtained at 5.0-5.9 weeks demonstrated at least a singleton intrauterine pregnancy and (2) a subsequent sonogram at 6.0 weeks or beyond demonstrated a living multiple gestation. Twenty-four (11%) of 213 dichorionic twin gestations were initially undercounted as singletons, as were six (86%) of seven monochorionic twin gestations. Among 105 higher order multiples, 17 (16%) were undercounted initially. All but one of the undercounted cases were scanned transvaginally. Undercounting occurred in both natural and assisted conceptions, and it occurred more frequently on sonograms obtained at 5.0-5.4 weeks than at 5.5-5.9 weeks (P = 0.02, Fisher's exact test). Prognosis for undercounted multiple gestations was similar to that of correctly counted ones with respect to several measures of pregnancy outcome, including the likelihood that all fetuses would be delivered liveborn, gestational age at birth, and birth weight (P > 0.20, all comparisons). In conclusion, transvaginal sonography at 5.0-5.9 weeks frequently undercounts multiple gestations. Initially undercounted multiple gestations and those correctly counted have similar pregnancy outcomes.

Diagnostic Errors↗
PubMed1998

Multifetal pregnancy reduction of both fetuses of a monochorionic pair by intrathoracic potassium chloride injection of one fetus.

The purpose of this study was to determine if a monochorionic pair of fetuses in a higher-order multiple gestation can be reduced by injecting only one fetus with potassium chloride. Three quadruplet and two quintuplet gestations, each with a monochorionic pair of fetuses, were referred for pregnancy reduction. In each case, reduction was performed by injecting one of the monochorionic pair with potassium chloride. Patients returned for a follow-up sonogram within 1 week of the procedure. The reductions were performed at an average 12.1 weeks' gestation, with a range of 10.7 to 14.0 weeks. Follow-up scans 4 to 7 days after the procedure showed that both monochorionic fetuses were dead and all other fetuses were alive. One quintuplet pregnancy underwent a second reduction procedure to twins. One quintuplet and two quadruplet pregnancies that were reduced to twins resulted in the birth of live twins between 30.8 weeks and 36.8 weeks' gestations. The third quadruplet pregnancy reduced to twins is still ongoing; the mother is pregnant with twins at 20 weeks' gestation. The quintuplet pregnancy reduced to triplets resulted in delivery of live triplets at 24.1 weeks' gestation, but two of the neonates died in the first few days of life. Reduction of both fetuses of a monochorionic pair in a higher-order multiple gestation can be accomplished by intrathoracic injection of potassium chloride into only one of the pair.

Female↗
PubMed1997

Early singleton pregnancy outcome: effects of maternal age and mode of conception.

PURPOSE: To assess the effect of prognostic factors on the outcome of singleton pregnancies. MATERIALS AND METHODS: First-trimester ultrasonographic (US) scans that demonstrated a living fetus in 4,156 consecutive singleton pregnancies were studied. The relationship between outcome and maternal age, mode of conception, maternal symptoms, and US findings was evaluated. RESULTS: Spontaneous abortion occurred in 371 of 4,156 (8.9%) cases. Higher pregnancy-loss rates were associated with older maternal age (P < 10(-5)), assisted mode of conception (P < 10(-8)), maternal symptoms of pain and/or bleeding (P < .001), and abnormal US findings (P < 10(-8)). US abnormalities were more frequent in older women than in younger women (P < 10(-5)) and in assisted conceptions than in natural conceptions (P < 10(-8)). At stepwise logistic regression, with gestational age as a covariate, US abnormalities and maternal symptoms independently affected pregnancy outcome. Maternal age and mode of conception had no further statistically significant effect on pregnancy outcome. CONCLUSION: The prognosis for older mothers and for those with assisted conception is not statistically significantly different from that for younger mothers and for those with natural conception if maternal symptoms, US findings, and gestational age are the same.

Abortion, Spontaneous↗
PubMed1997

Solid extratesticular masses evaluated with sonography: pathologic correlation.

PURPOSE: To determine if the sonographic appearance of solid extratesticular masses enables distinction of benign from malignant disease. MATERIALS AND METHODS: Sonograms of 19 patients with palpable testicular masses who underwent biopsy were reviewed retrospectively. Appearances of masses on sonograms were correlated with pathologic diagnoses. RESULTS: All masses were well defined and ranged in size from 5.7 to 66.7 mm (mean, 21 mm). On the sonograms, five masses were within the epididymis, and six were distinct from it; seven cases were indeterminate. The epididymis was surgically absent in the remaining patient. Sonographic echogenicity ranged from hypoechoic to hyperechoic relative to that of the testis. At pathologic evaluation, there were 16 (84%) benign and three (16%) malignant lesions. Benign lesions consisted of six adenomatoid tumors, two lipomas, two epidermoid inclusion cysts, two cases of sarcoidosis, and one case each of sperm granuloma, spermatic cord leiomyoma, benign inflammatory nodule, and fibroma. The malignant lesions consisted of scrotal wall liposarcoma, epididymal leiomyosarcoma, and recurrent spindle cell malignancy of the spermatic cord. No sonographic features of masses were useful for distinguishing benign from malignant lesions. CONCLUSION: The frequency of malignancy (16%) contrasts with prior reports that suggest a very low rate of malignancy among these masses. Sonography is useful for identifying the extratesticular location of a mass but not for distinguishing the nature of the lesion.

Adult↗
PubMed1997

Clinical significance of isolated enlargement of the cisterna magna (> 10 mm) on prenatal sonography.

Enlargement of the cisterna magna has been reported to be associated with aneuploidy. In prior studies of cisterna magna enlargement, however, those fetuses with abnormal chromosomes have had other sonographic abnormalities in addition to a large cisterna magna. Our goal was to assess the clinical significance of the isolated finding of a cisterna magna measuring more than 10 mm in anteroposterior dimension on a prenatal sonogram. We retrieved all prenatal sonograms performed at our institution between 1989 and 1996 in which an enlarged cisterna magna was the only sonographic abnormality. Cases were included in our study if the cisterna magna measured more than 10 mm in the appropriate plane and the fetal survey was otherwise normal, including normal cerebellar size and morphology. Pregnancy outcome and postnatal follow-up were obtained in each case. Fifteen cases comprised our study population. In all 15 fetuses, the enlarged cisterna magna was first seen in the third trimester (gestational age range, 26 to 37 weeks). The cisterna magna ranged from 11 to 19 mm in size (mean, 12.9 mm). All 15 pregnancies resulted in phenotypically normal liveborn infants. All the mother and infants had short hospital stays (1 to 4 days), and the infants were normal at discharge. Longer follow-up was available in eight cases (range, 2 to 69 months), and all eight of these infants were normal. Our results suggest that isolated enlargement of the cisterna magna to more than 10 mm is associated with normal pregnancy and neonatal outcome.

Cisterna Magna↗
PubMed1997

Improved birth weight table for neonates developed from gestations dated by early ultrasonography.

Most previously published tables of birth weight percentiles as a function of gestational age have been derived from neonates with imprecise gestational dating. In order to improve the accuracy of neonatal birth weight percentiles, we developed a birth weight table based on measurements from a group of neonates who had accurate gestational dating by prenatal first trimester ultrasonography. By matching a database of obstetrical ultrasonograms over a 5 year period to birth records at our institution, 3718 newborn infants with gestational dating by first trimester ultrasonography were identified. Statistical smoothing and regression techniques were applied to gestational age at birth and birth weight data to develop a table for the 10th, 50th, 90th, and other weight percentiles for 25 weeks of gestation onward. The weight table developed from our population has lower 50th and 90th percentile weights, and narrower 10th to 90th percentile ranges, at 25 to 35 weeks than in prior tables. At 39 to 43 weeks, our 10th, 50th, and 90th percentile weights are higher than those in previous tables. Our weight table for newborn infants, based on measurements from neonates with accurate dating, permits improved assignment of weight percentiles for gestational age and more accurate diagnosis of growth disorders in fetuses and neonates.

Birth Weight↗
PubMed1996

Role of Doppler ultrasonography in the prediction of pregnancy outcome in women with recurrent spontaneous abortion.

We prospectively studied 96 patients with a history of recurrent spontaneous abortion to determine whether the resistive index of the main uterine artery or subchorionic vessels can allow prediction of pregnancy outcome. The subchorionic RI declined progressively for a mean of 0.54 at 6 weeks to 0.42 at 13 weeks (P < 10(-8), F-test). No significant difference was found in subchorionic RI values between outcomes for liveborn infants versus loss. Uterine artery RI values also declined significantly through the first trimester (P < 10(-8), F-test). Uterine artery RI values tended to be lower in pregnancies ending in loss than in successful gestations; however, there was too much overlap for this index to be clinically useful. In conclusion, first trimester RI does not allow prediction of pregnancy outcome in patients with recurrent abortion.

Abortion, Habitual↗
PubMed1996

Burned-out primary testicular cancer: sonographic and pathological characteristics.

PURPOSE: Rarely, a testicular scar is discovered in a patient with a presumed extragonadal germ cell tumor. Of 6 patients originally diagnosed with retroperitoneal extragonadal germ cell tumors who had echogenic foci on scrotal sonography 5 had definite histological evidence of a regressed primary testicular cancer. MATERIALS AND METHODS: Six men 21 to 36 years old presented with palpably normal testes and a presumed retroperitoneal extragonadal germ cell tumor. After chemotherapy each patient underwent retroperitoneal lymph node dissection and ipsilateral orchiectomy. The entire testis was submitted for histological evaluation and all calcifications were identified. RESULTS: Scrotal sonography revealed an echogenic focus or foci in all cases, which corresponded to intratubular hematoxyphilic bodies in 2. In 3 cases the echogenic foci were intratubular psammoma bodies close to a fibrous scar with hemosiderin deposition, 1 of which contained a focus of intratubular germ cell neoplasia. The hematoxyphilic bodies appeared larger and more intensely echogenic on sonography than the psammoma bodies. The remaining case had stromal calcifications near the rete testis. CONCLUSIONS: The hematoxyphilic bodies and fibrosis with hemosiderin deposits are believed to represent remnants of testicular carcinoma. Our finding of intratubular germ cell neoplasia provides further proof that testicular carcinomas regress. In 5 of 6 patients (83%) with presumed extragonadal germ cell tumors we showed definite pathological evidence of a burned-out testicular carcinoma. With a presumed retroperitoneal germ cell tumor and palpably normal testes, sonographic demonstration of an echogenic lesion in the absence of a hypoechoic mass probably represents a burned-out primary neoplasm.

Adult↗
PubMed1995

Increasing curvature of the normal fetal ductus arteriosus with advancing gestational age.

In order to determine whether the configuration of the normal fetal ductus arteriosus changes with increasing gestational age, we prospectively collected oblique transverse sonographic images of the fetal thorax through the ductus arteriosus. Scans from 240 consecutive normal fetuses with gestational age 20 weeks or more were included in the study. The images were reviewed independently by two sonologists and the ductus arteriosus was graded as: (1) straight; (2) mildly curved (C-shaped, bending < 90 degrees from a straight line); or (3) markedly curved (C-shaped, bending > 90 degrees, or S-shaped). In cases where the two sonologists' gradings did not concur, the images were re-reviewed jointly by both sonologists and a grading was assigned by consensus. Forty-two cases were rejected, due to inadequate images. The ductus arteriosus was graded in 42 fetuses aged 20-25.9 weeks, 48 at 26-31.9 weeks, 74 at 32-37.9 weeks, and 34 at 38 weeks or more for a total of 198 cases. There was a significant trend to greater curvature with increasing gestational age (p < 0.0001). The frequency of a straight ductus arteriosus decreased steadily from 55% of fetuses aged 20-25.9 weeks to 3% of fetuses at 38 weeks or older, while the frequency of marked curvature increased from 2% in the youngest age group to 56% in the oldest. The proportion with mild curvature showed little variation throughout gestation. In summary, the configuration of the ductus arteriosus is variable but tends to become more curved as pregnancy proceeds. Marked curvature or tortuosity of the ductus arteriosus should not be misinterpreted as a great vessel anomaly.

Ductus Arteriosus↗
PubMed1995

Sonographic evaluation of intrauterine growth retardation.

Intrauterine growth retardation (IUGR) may arise from a variety of causes, including placental insufficiency, maternal diseases, and fetal anomalies. Sonography plays a number of important roles in the diagnosis and management of growth retardation. Diagnosis of IUGR is based on fetal measurements, assessment of amniotic fluid volume, and other sonographic findings. Once IUGR has been diagnosed, sonography can help establish its cause. If a lethal cause is excluded, the fetus is monitored for the remainder of the pregnancy using sonography, including serial fetal measurements, biophysical profiles, and Doppler waveform indexes. Used appropriately, sonography can improve the outcome of fetuses with IUGR.

Female↗
PubMed1995

Embryonic heart rate in the early first trimester: what rate is normal?

Embryonic heart rates below 90 beats per minute at 6 to 8 weeks of gestation have been shown to be associated with a high likelihood of subsequent first trimester demise. The boundary between slow and normal heart rates has not been established, however, in that previous studies do not identify the heart rate for each gestational age at which prognosis plateaus. We evaluated sonograms of singleton pregnancies at 6 to 8 weeks to determine the relationship between heart rate and first trimester outcome in four gestational age subgroups: < or = 6.2, 6.3-7.0, 7.1-7.5, and 7.6-8.0 weeks. Below 6.2 weeks, prognosis improved as heart rate increased to 100 beats per minute, then plateaued for rates > or = 100 beats per minute. At 6.3-7.0 weeks, prognosis improved up to 120 beats per minute, then plateaued. Heart rate norms could not be established at 7.1-8.0 weeks because of the small number of embryonic or fetal deaths in this age group; however, all embryos with heart rates below 110 beats per minute at 7.1-8.0 weeks died. We conclude that the lower limit of normal is 100 beats per minute up to 6.2 weeks' gestation and 120 bpm at 6.3-7.0 weeks.

Adult↗
PubMed1994

Ovarian masses: can benign and malignant lesions be differentiated with color and pulsed Doppler US?

PURPOSE: To determine whether color and pulsed Doppler ultrasound (US) can be used to differentiate benign from malignant ovarian masses. MATERIALS AND METHODS: Forty-four ovarian masses identified with sonography in 40 patients were confirmed at surgery (n = 35) or followed up to resolution with US (n = 9). Color and pulsed Doppler US were used to calculate the lowest pulsatility index (PI) and resistance index (RI) for each mass. RESULTS: Color Doppler US enabled detection of arterial flow in 24 of 36 benign masses and six of eight malignant masses. PI was lower in malignant masses than in benign masses (P = .002), as was RI (P = .001). Both indexes demonstrated overlap between benign and malignant masses; therefore, no cutoff value for either index had both high sensitivity and high specificity for malignancy: For PI cutoff of 1.0, sensitivity and specificity were 100% and 46%, respectively; for RI cutoff of 0.4, 50% and 96%. CONCLUSIONS: While PI and RI tend to be lower in malignant ovarian masses, neither index can be used reliably to differentiate benign from malignant lesions. In addition, lack of detectable flow by means of color Doppler US does not exclude ovarian malignancy.

Adult↗