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Biomedical subjects

C B Benson

Publications and source records attributed to C B Benson.

At least 55 records · Page 3Linked to original sources
PubMed1994

Cervical ectopic pregnancy: results of conservative treatment.

PURPOSE: To review experience with early sonographic diagnosis and fertility-preserving treatment of cervical ectopic pregnancy. MATERIALS AND METHODS: The authors evaluated 12 consecutive cases of cervical ectopic pregnancy diagnosed with ultrasound (US) and treated with methods that successfully preserved the uterus. Gestational age, sonographic findings, means of conception, and method of treatment were recorded. RESULTS: Gestational age at diagnosis ranged from 5.0 to 7.9 weeks. Cardiac activity was documented in nine cases. Patients were treated as follows: transvaginal US-guided injection of potassium chloride into the embryo or gestational sac (n = 6), uterine artery embolization followed by dilation and evacuation (n = 4), dilation and evacuation after ligation of uterine artery branches (n = 1), and uterine artery embolization followed by administration of systemic methotrexate (n = 1). The cervical pregnancy was successfully ablated with one treatment in all cases. No patient required hysterectomy, and only one patient required transfusion. Two patients subsequently delivered healthy babies; three other patients have been able to conceive successfully. CONCLUSION: When cervical ectopic pregnancy is diagnosed early, US-guided termination or other conservative procedures allow preservation of the uterus, thus maintaining potential fertility.

Cervix Uteri↗
PubMed1994

Sonography of the fetal posterior fossa: false appearance of mega-cisterna magna and Dandy-Walker variant.

PURPOSE: To establish that incorrect scanning of the fetal posterior fossa may falsely create the appearance of a mega-cisterna magna (MCM) or Dandy-Walker variant (DWV). MATERIALS AND METHODS: After routine sonography, 100 consecutive fetuses (gestational age range, 25-40 weeks) without abnormality underwent additional posterior fossa scanning in an attempt to create the appearance of an MCM (anteroposterior diameter larger than 10 mm) or DWV. Sonograms were obtained in a plane inferior to or angled more coronally than the routine axial plane. RESULTS: The posterior fossa was depicted in 93 fetuses. Pseudo-MCM occurred in 35 (38%) of 93 fetuses: 12 (30%) of 40 fetuses aged 25.0-29.9 weeks, 11 (50%) of 22 fetuses aged 30.0-34.9 weeks, and 12 (39%) of 31 fetuses aged 35.0-40.0 weeks. Pseudo-DWV occurred in 40 (43%) of 93 fetuses: 20 (50%) of 40 fetuses aged 25.0-29.9 weeks, 12 (55%) of 22 fetuses aged 30.0-34.9 weeks, and eight (26%) of 31 fetuses aged 35.0-40.0 weeks. CONCLUSION: Sonography of the posterior fossa in an angled semi-coronal plane should be avoided because it may create an appearance that mimics an abnormality.

Artifacts↗
PubMed1994

Slow embryonic heart rate in early first trimester: indicator of poor pregnancy outcome.

PURPOSE: To assess the outcome of early first-trimester pregnancies with slow embryonic heart rates. MATERIALS AND METHODS: Forty pregnant women had prenatal ultrasound scans obtained before 8 weeks gestation that demonstrated an embryonic heart rate of 90 beats per minute or less. Follow-up information was used to determine pregnancy status at the end of the first trimester. RESULTS: Thirty-two embryos died before the end of the first trimester, five survived the first trimester, and three were lost to follow-up. Fetal demise occurred in all seven embryos with heart rates of less than 70 beats per minute, 10 of 11 with heart rates of 70-79 beats per minute, and 15 of 19 with heart rates of 80-90 beats per minute. All 32 pregnancy losses occurred within 10.5 weeks gestation. CONCLUSION: An embryonic heart rate of 90 beats per minute or less early in the first trimester carries a dismal prognosis, with a very high likelihood of fetal demise before the end of the first trimester. Demise occurred in all embryos with heart rates less than 70 beats per minute.

Female↗
PubMed1994

Distal ureteral calculi: detection with vaginal US.

PURPOSE: To describe the use of vaginal ultrasonography to identify distal ureteral calculi and hydroureter. MATERIALS AND METHODS: Abdominal and vaginal sonography were performed in 13 women with distal ureteral calculi. Indications for sonography included flank pain, hematuria, and suspected appendicitis. Six patients were pregnant. RESULTS: In each patient, vaginal sonograms demonstrated a distal ureteral calculus; in only two cases was the calculus detected with transabdominal sonography. Distal hydroureter was identified with vaginal scanning in each patient but with abdominal scanning in only two. Hydronephrosis was absent in three patients, mild in six, and moderate in four. Symmetric ureteral jets were noted at transabdominal sonography in two of nine patients. Follow-up transvaginal scans obtained shortly after passage of stones in two patients revealed swelling of the trigone but normal ureteral jets. CONCLUSION: In symptomatic female patients, use of vaginal sonography should be considered to evaluate the distal ureter for calculi, particularly if the results of transabdominal examination are normal or inconclusive.

Adult↗
PubMed1994

Prognosis of first-trimester twin pregnancies: polychotomous logistic regression analysis.

PURPOSE: To determine which clinical and sonographic characteristics independently affect the prognosis of first-trimester twin pregnancies and to develop formulas for calculating the probabilities of the pregnancy resulting in two, one, or no liveborn infants. MATERIALS AND METHODS: The authors prospectively identified 137 twin pregnancies with two heartbeats at first-trimester sonography and with known pregnancy outcome. Stepwise polychotomous logistic regression analysis was used to identify characteristics that have an independent statistically significant relationship with pregnancy outcome and to develop outcome-prediction formulas. RESULTS: Of 137 patients, 110 (80.3%) had viable twins, 12 (8.8%) had one infant, and 15 (10.9%) had none. Gestational age, chorionicity, and sonographic findings were independent, statistically significant (P < .05) prognostic factors, while maternal age, method of conception, and indication for sonography were not. CONCLUSION: The logistic regression formulas involving the three independent prognostic factors can be used in the first trimester to predict pregnancy outcome.

Adult↗
PubMed1994

Clinical significance of isolated fetal pericardial effusion.

Prenatal sonographic identification of a small rim of pericardial fluid, measuring less than 2 mm in thickness, is a normal finding. Pericardial fluid 2 mm or greater in thickness may be associated with structural anomalies or hydrops, but its clinical significance in the absence of these associated findings has not been evaluated. We assessed the outcome in fetuses with isolated pericardial effusions of at least 2 mm thick. Our study population included 52 fetuses with effusions ranging from 2 to 7 mm in thickness. We compared rates of preterm delivery, cesarean section, intrauterine growth retardation, perinatal complications, Apgar scores, and length of neonatal hospital stay in these 52 cases to the overall hospital rates and found no statistically significant difference. We conclude that in the absence of other sonographic abnormalities, the finding of a fetal pericardial fluid collection 2 to 7 mm in thickness is not associated with adverse outcome.

Female↗
PubMed1993

Outcome of twin gestations following sonographic demonstration of two heart beats in the first trimester.

We conducted a prospective study to assess pregnancy outcome following a first-trimester ultrasound examination demonstrating intrauterine twins with heart beats. Our study population included 68 cases of twin gestations in which a first-trimester scan demonstrated two heart beats. We correlated pregnancy outcome with placentation type, gestational age, maternal age, and method of conception. There were 59 dichorionic and nine monochorionic gestations. Twenty-six of the dichorionic pregnancies resulted from treatment for infertility. Among all 68 cases, 54 (79%) delivered viable twins, eight (12%) delivered one infant, and six (9%) delivered none. The outcome in dichorionic gestations (83% delivered twins, 12% singletons, 5% none) was significantly better than in monochorionic gestations (56%, 11%, 33%, respectively) (p < 0.05). Among dichorionic twins, pregnancy outcome was worse in twins initially identified on a 6-7.9 week ultrasound examination (74% delivered twins, 21% singletons, 6% none) as compared to those identified at 8-13 weeks (96%, 0%, 4%, respectively) (p < 0.05). The outcome in dichorionic gestations was worse in women over 35 compared to those under 35 (p < 0.05), and those with treatment for infertility compared to those who conceived naturally (p = 0.05). These results provide prognostic information about outcome of twin pregnancies scanned in the first trimester as a function of chorionicity, gestational age, maternal age, and method of conception.

Journal Article↗
PubMed1993

Correlation of duplex sonography with arteriography in patients with erectile dysfunction.

OBJECTIVE: Our objective was to assess the accuracy of using measurements of peak systolic velocity in the cavernosal artery for the diagnosis of arteriogenic impotence. MATERIALS AND METHODS: Twenty consecutive men with erectile dysfunction had duplex sonography after intracavernosal injection of papaverine to induce an erection. Peak systolic velocities in the right and left cavernosal arteries were measured by using Doppler sonography. Right and left selective penile arteriography was performed with low-osmolality contrast media after intracavernosal injection of papverine and intraarterial tolazoline. On the basis of the angiographic findings, penile arterial function was classified as normal, moderately insufficient, or severely insufficient. Doppler measurements of peak systolic velocity were correlated with arteriographic results. RESULTS: All 11 cavernosal arteries with peak velocities less than 25 cm/sec were associated with arterial disease, nine severe and two moderate. Thirteen of 17 carvernosal arteries with peak systolic velocities 25-34 cm/sec were associated with arterial disease, five severe and eight moderate. Only one of the 12 cavernosal arteries with peak velocity at or greater than 35 cm/sec was associated with arterial disease. CONCLUSION: We conclude that peak systolic velocity in the cavernosal artery as measured on duplex sonography is an accurate predictor of arterial disease in patients with erectile dysfunction. A peak systolic velocity of at least 35 cm/sec indicates normal arterial supply. At peak systolic velocities less than 35 cm/sec, the likelihood and severity of arterial disease increase as the peak systolic velocity decreases, with a peak velocity less than 25 cm/sec indicating a high likelihood of severe arterial disease.

Adult↗
PubMed1993

Sonography of the fetal heart: normal variants and pitfalls.

Sonographic evaluation of the fetal heart is an important part of obstetric sonography. The sonographer and sonologist should be familiar with the sonographic appearance of the normal fetal heart and with common structural abnormalities. Occasionally, normal structures in or adjacent to the fetal heart may simulate an abnormality. Although one should seek consultative sonography in instances of uncertain or questionable findings, unnecessary referral and concern may be avoided in some cases if the sonologist is familiar with normal variants and pitfalls. In this pictorial essay, we present several such pitfalls that we and others have observed in the four-chamber view (Fig. 1) and in views of the ventricular outflow tracts (Figs. 2 and 3).

Female↗
PubMed1993

Improved prediction of gestational age in the late third trimester.

A variety of formulas have been published for predicting GA in the second and third trimesters. We assessed these formulas for the presence of systematic errors. Our study population consisted of 1036 obstetrical sonograms at 14 to 42 weeks' gestation in patients with highly accurate dating based on a prior first trimester scan. Most formulas had mean errors (mean value of the difference between predicted and true GA) of no more than 1 week between 14 and 38 weeks' gestation. At 38 to 42 weeks, however, all formulas had large systematic underestimation biases, with mean negative errors in the range of 1.6 to 3 weeks. By regressing ln(GA) against one or more measurements, we developed new formulas that eliminate this underestimation bias, with mean errors of no more than 0.6 week throughout the entire 14 to 42 week period. As with current formulas, however, our formulas have wide 95% confidence ranges of +/- 3 weeks or greater at 38 to 42 weeks as a result of inherent biological variability. We recommend the use of these formulas in clinical practice, as they may prevent errors in diagnosis late in pregnancy.

Anthropometry↗
PubMed1993

Pregnancy outcome after a first trimester sonogram demonstrating fetal cardiac activity.

We conducted a prospective study to assess pregnancy outcome after a first trimester sonogram demonstrating a singleton intrauterine gestation with fetal cardiac activity. In each of the 556 cases, data recorded included indication for the sonogram, results of the sonogram, and pregnancy outcome. Sonographic abnormalities were found more frequently in patients scanned because of symptoms (14.0%) than among patients scanned for routine indications (6.0%) (P < 0.05, chi-squared). Among 556 patients with known outcomes, the overall loss rate was 9.4%. A trend was seen toward a higher loss rate in patients with abnormal than normal sonograms (15.2% versus 8.8%). The loss rate after a normal scan was similar in symptomatic (10.6%) and asymptomatic patients (9.1%) and declined progressively with gestational age from 17.0% at 6 to 7.9 weeks to 4.3% at 12 to 13 weeks (P < 0.01, chi-squared). These results can be used to convey prognostic information to patients after a normal first trimester sonogram demonstrating fetal cardiac activity. The likelihood of a good pregnancy outcome can be stated as a function of gestational age, and a symptomatic patient can be reassured after a normal scan that her prognosis is similar to that of an asymptomatic patient with a normal sonogram.

Abortion, Spontaneous↗
PubMed1993

The effect of operative technique and uterine size on blood loss during myomectomy: a prospective randomized study.

OBJECTIVES: To compare operative blood loss between two accepted blood loss-reducing techniques used during myomectomy and to evaluate the effect of preoperatively determined uterine volume on blood loss. DESIGN: Subjects were stratified by ultrasound-determined uterine volume < 600 cm3 (n = 11) and > or = 600 cm3 (n = 10) and then randomized into treatment groups. The same radiologist, surgeons, and anesthetic induction technique were involved in every case. In the pharmacologic technique, diluted vasopressin (20 U in 20 mL normal saline) was injected into the serosa and/or myometrium overlying the fibroid(s) before the uterine incision(s). In the mechanical technique, a penrose drain tourniquet was passed through defects created in the broad ligaments at the level of the internal os and secured posteriorly, occluding the uterine vessels. In addition, vascular clamps were placed on the infundibulopelvic ligaments, occluding anastomotic blood flow through the ovarian vessels. RESULTS: There was no difference in operative blood loss, operating time, preoperative and intraoperative mean arterial blood pressures, postoperative febrile morbidity, preoperative and postoperative hematocrits, transfusion rates, and length of hospital stay between groups. Blood loss was significantly greater for uteri with ultrasound-determined volumes > or 600 cm3 (627 +/- 175 mL, mean +/- SEM) than for those < 600 cm3 (228 +/- 49 mL). For all subjects, blood lost while operating on the uterus (mean, 379 mL; range, 35 to 1,968 mL) was positively correlated with the total weight of the fibroids resected and with time spent operating on the uterus. Total blood loss (mean, 418 mL; range, 42 to 1,968 mL) was also positively correlated with the time spent operating on the uterus and with total operating time. CONCLUSIONS: There were no demonstrable differences in blood loss, morbidity, or transfusion requirements between subjects undergoing myomectomy using pharmacologic vasoconstriction and mechanical vascular occlusion techniques. Blood loss during myomectomy is primarily incurred while operating on the uterus and is correlated with preoperative uterine size, total weight of fibroids removed, and operating time.

Adult↗
PubMed1992

Utility of high-resolution ultrasound for the diagnosis of dialysis-related amyloidosis.

OBJECTIVE: To evaluate the utility of real-time, high-resolution ultrasound of the shoulder in the diagnosis of dialysis-related amyloidosis. METHODS: We performed a case series study of 2 groups of patients seen at a referral-based clinic in a tertiary care hospital. The shoulders of 13 patients with normal renal function and of 38 patients receiving long-term hemodialysis were studied by real-time, high-resolution ultrasound. All hemodialysis patients were evaluated clinically for the presence of dialysis-related amyloidosis. Surgical specimens of joints were available for all 13 patients with normal renal function and for 17 of the 38 hemodialysis patients. These specimens were evaluated for the presence of beta 2-microglobulin (beta 2m) amyloid by Congo red and immunohistochemical staining. RESULTS: Two ultrasonographic findings were selectively observed in the dialysis patients with clinical and histologic evidence of beta 2m amyloid in comparison with patients with normal renal function and no evidence of amyloid: rotator cuffs greater than 8 mm in thickness and echogenic pads between muscle groups of the rotator cuff. The presence of at least 1 of these 2 findings corresponded to the presence of clinically and histologically evident beta 2m amyloid with a sensitivity of 79% and a specificity of 100%. When additional patients without surgical specimens for histologic confirmation of amyloidosis were included, the sensitivity of these 2 sonographic findings was 72% and the specificity was 97%. CONCLUSION: Real-time, high-resolution ultrasound is a relatively sensitive and highly specific noninvasive adjunct to the clinical diagnosis of beta 2m amyloidosis in patients receiving long-term hemodialysis.

Adult↗
PubMed1992

Echogenic material in the fetal gallbladder: sonographic and clinical observations.

Obstetric sonograms of 26 fetuses with echogenic material in the gallbladder were reviewed to describe the sonographic findings and clinical significance. Gestational age at the time of diagnosis ranged from 28 to 42 weeks (mean, 36.2 weeks). The echogenic foci were associated with distal shadowing in eight fetuses (30%), comet-tail artifact in nine (35%), and no distal artifact in nine (35%). No hemolytic anemias, other predisposing risk factors, or clinical sequelae associated with biliary tract disease were identified in any of the infants. Postnatal sonographic or pathologic follow-up studies were available in 17 cases. In nine of these 17 infants, the echogenic foci had resolved. In three, the foci have persisted, but none of the children have become symptomatic; the longest period of follow-up with stones still present is 4 1/2 years. Whether all echogenic foci in the fetal gallbladder represent true gallstones remains unknown. Echogenic foci may be seen in the fetal gallbladder during the third trimester. No predisposing fetal risk factors or clinical sequelae were evident in our series. Many echogenic foci, but not all, will resolve.

Anemia, Hemolytic↗
PubMed1992

Cystic testicular mass caused by dilated rete testis: sonographic findings in 31 cases.

We reviewed the scrotal sonograms of 31 patients who had a testicular mass consisting of multiple small spherical or tubular anechoic structures in the region of the mediastinum testis. The median age of the patients was 62 years (range, 31-76 years). The abnormality was unilateral in 22 patients and bilateral in nine. Thirty-four (85%) of the 40 involved testicles had coexisting epididymal abnormalities: 32 with epididymal cysts and two with epididymitis. Follow-up sonograms were available in five patients and showed no change up to 4.5 years after the initial diagnosis. Surgical and histologic findings were available in one other patient and showed dilatation of the rete testis. The sonographic appearance and location of the lesions, the frequent presence of an epididymal abnormality, and the surgical and histologic findings in one case suggest that the lesion is due to dilatation of the rete testis, probably associated with obstruction in the epididymis. Recognition of this entity on sonograms may prevent unnecessary orchiectomy.

Adult↗
PubMed1992

First trimester findings in pregnancies after in vitro fertilization.

We assessed the frequency of abnormal sonographic findings and their significance with respect to outcome in pregnancies resulting from in vitro fertilization (IVF). We retrospectively reviewed first trimester sonograms of 53 consecutive IVF patients who had a positive pregnancy test and first trimester ultrasonography at least 4 weeks after embryo transfer, and we correlated the sonographic findings with pregnancy outcome. For controls, we compared the frequency of sonographic abnormalities in these study patients to that in a group of patients who became pregnant after ovulation induction only. In the 53 IVF patients, the numbers of gestational sacs identified on the initial sonogram were as follows: 34 singletons, 11 twins, two triplets, one quadruplets and one quintuplets; no sac was seen in four patients. In 32 patients, the first sonogram was normal, with a visualized yolk sac, or heartbeat, or both. In 10 patients the gestational sac appeared abnormal but sac contents were normal. In seven patients an abnormality of sac contents was identified, including four with an embryo but no heartbeat and three anembryonic sacs. Overall, 40% of IVF patients had sonographic abnormalities, in comparison to 7% in the control group of patients (P less than 0.05, Fisher's exact test). Of the 32 patients with normal sonograms, 26 (81%) delivered at least one live infant. Of the 10 patients whose gestation sacs appeared abnormal, nine (90%) gave birth to live infants. Of the seven patients with abnormal sac contents, two (29%) delivered at least one live infant. We conclude that abnormal findings are frequently present on the initial sonogram of pregnant patients after IVF.(ABSTRACT TRUNCATED AT 250 WORDS)

Embryo Transfer↗
PubMed1991

Sonographic prediction of gestational age: accuracy of second- and third-trimester fetal measurements.

We measured the accuracy of second- and third-trimester sonographic predictors of gestational age against highly reliable gold standard (crown-rump length) in a group of fetuses. Using a prospectively collected computerized data base, we selected 460 fetal sonograms obtained at 14-42 weeks of gestation in which age could be reliably established on the basis of crown-rump length in the first trimester. We used data obtained from these sonograms to compare several predictors of fetal age. The accuracy of all predictors worsened progressively as pregnancy proceeded. In the second trimester, corrected biparietal diameter and head circumference were more accurate predictors of gestational age than were biparietal diameter, femoral length, and abdominal circumference (p less than .05, F test). In the third trimester, the corrected biparietal diameter, head circumference, and femoral length were the best predictors, significantly better than biparietal diameter and abdominal circumference (p less than .05, F test). Prediction of gestational age that relies on a single sonographic measurement should be based on the head circumference or corrected biparietal diameter in the second trimester and on one of these two predictors or the femoral length in the third trimester.

Female↗