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Biomedical subjects

C B Benson

Publications and source records attributed to C B Benson.

At least 73 records · Page 4Linked to original sources
PubMed1991

Amniotic fluid volume in large-for-gestational-age fetuses of nondiabetic mothers.

Large-for-gestational-age (LGA) fetuses, especially those whose birth weight is greater than 4000 g, are at elevated risk for obstetrical complications. Prenatal diagnosis of the condition has been limited by the inaccuracy of fetal weight estimation and by low positive predictive values of other sonographic parameters. We studied 412 fetuses, 35 LGA and 377 non-LGA, who were scanned within 1 week of delivery, to determine if assessment of amniotic fluid volume can be used to improve the accuracy of fetal weight estimation for diagnosing or excluding LGA. In our study, the positive and negative predictive values of fetal weight estimation alone were 47% and 95%, respectively. The distribution of amniotic fluid volumes in LGA and non-LGA fetuses differed significantly (P less than .001). Polyhydramnios occurred more frequently in LGA fetuses than non-LGA fetuses (17% vs 8%) but had little effect on the positive predictive value of a fetal weight estimate above the 90th percentile. Oligohydramnios occurred less frequently in LGA than non-LGA fetuses (3% vs 19%) and improved the negative predictive value of fetal weight estimation. In particular, the combination of oligohydramnios and a fetal weight estimate below the 90th percentile virtually excluded the possibility of LGA.

Amniotic Fluid↗
PubMed1991

Acute diseases of the scrotum.

Several imaging modalities are available for evaluating the patient with acute scrotal pain. Until recently, scintigraphy was the initial procedure of choice in most patients, as it was the only noninvasive technique for determining integrity of blood flow to the testicle. Ultrasound was valuable when the scintiscan was inconclusive or in the setting of scrotal trauma. With the advent of color Doppler sonography, information about both structure and blood flow can be obtained by means of a single imaging study. If initial promising results with this newer technique are borne out, color Doppler is likely to become the primary diagnostic test in patients with acute scrotal pain. The role of MRI and MRS has yet to be defined.

Acute Disease↗
PubMed1991

The penis.

Explore the source record for details and available documents.

Diagnostic Imaging↗
PubMed1991

Sonography of the musculoskeletal system.

High-resolution ultrasound is an imaging technique with increasing applications in the musculoskeletal system. With the development of high-frequency, realtime transducers, detailed images of small superficial structures can be provided. Tendons, muscles, and subcutaneous tissues can be assessed for disruption, masses, or fluid collections. Foreign bodies can be localized to guide surgical excision. Increased use of this diagnostic tool may lead to new applications as the technology improves.

Bone and Bones↗
PubMed1990

Fetal growth disturbances.

IUGR is a fetal disorder characterized by diminished fetal growth, especially in the third trimester. Growth retardation may be due to primary placental insufficiency or may result from a variety of maternal or fetal causes and is associated with elevated perinatal mortality and morbidity. Numerous conventional and Doppler ultrasound criteria have been proposed for diagnosing IUGR prenatally, but none on its own permits confident diagnosis of this condition. Diagnosis or exclusion of IUGR can best be achieved by the combined use of three parameters: estimated fetal weight, amniotic fluid volume, and maternal hypertension. When IUGR is suspected based on these parameters, Doppler ultrasound can help to determine the prognosis. Large fetuses, particularly those weighing more than 4,000 grams at birth, are at risk for perinatal morbidity and mortality due to obstetrical complications. These fetuses occur more frequently and are at especially high risk in diabetic mothers. The estimated fetal weight is the most direct parameter for diagnosing LGA and macrosomia and is moderately accurate with positive predictive values up to 67% in the general population and 77% in diabetics. It can be an important factor in deciding on the route of delivery in diabetic mothers.

Female↗
PubMed1990

High resolution ultrasonography and pulsed wave Doppler for detection of corporovenous incompetence in erectile dysfunction.

Cavernosometry and cavernosography have been the primary modalities available for detection and mapping of corporovenous incompetence in patients with erectile dysfunction. These procedures are expensive, time-consuming and associated with some morbidity, prompting us to study a less invasive method, high resolution ultrasonography and pulsed wave Doppler ultrasound. We evaluated 13 patients with nonendocrinological, nonneurological erectile dysfunction by high resolution and Doppler ultrasound for flow in the dorsal and cavernosal veins after intracorporeal papaverine. All patients had a nonrigid response to papaverine and a mean maximum cavernous arterial systolic velocity of greater than 25 cm. per second. The 13 patients were subsequently studied by dynamic cavernosometry and cavernosography, which revealed evidence of venous incompetence (12 with dorsal venous leaks and 11 with cavernous venous leaks). Only 5 of the 12 patients with dorsal venous incompetence had flow detected in the dorsal vein by ultrasound and Doppler studies. High resolution and Doppler ultrasound was unable to detect leakage in the cavernous veins. Among the 2 groups of patients with dorsal venous leaks (those with and without flow detectable by Doppler ultrasound) there was no significant difference in mean cavernous artery diameter or mean cavernous arterial maximum velocity. Similarly, there was no significant difference between the 2 groups in induction, maintenance or initial decompression rates on cavernosometry. We conclude that high resolution and Doppler ultrasound cannot replace dynamic cavernosometry and cavernosography as the diagnostic modality for venous incompetence.

Blood Flow Velocity↗
PubMed1990

Intrauterine growth retardation: diagnosis based on multiple parameters--a prospective study.

A scoring system has previously been developed to diagnose intrauterine growth retardation (IUGR) based on three parameters: estimated fetal weight, amniotic fluid volume, and maternal blood pressure status. To test the IUGR score prospectively, the authors computed the score in 356 third-trimester fetuses, 39 growth retarded and 317 normal, scanned within 2 weeks prior to delivery. The IUGR score identified three groups, each with a distinct probability of IUGR: A score below 50 virtually excludes IUGR (3% probability), a score above 60 allows confident diagnosis (74% probability), and score of 50-60 is indeterminate (13% probability). The IUGR score performed best in patients with accurate dating by early ultrasound (US), but even among patients lacking accurate dating, the performance of the IUGR score was superior to that previously reported for any single sonographic parameter. The IUGR score can be used in any US facility to diagnose or exclude third-trimester IUGR.

Female↗
PubMed1990

Sonography of multiple gestations.

Ultrasound plays an important role in the management of multiple gestations in several key areas: (1) diagnosing multiple gestation and determining fetal number; (2) determining placentation; (3) diagnosing complications; (4) guiding procedures; and (5) identifying fetal lie late in pregnancy. The information obtained from single or serial ultrasound examinations can lead to improved obstetric decision-making and thereby to improved outcome in these high-risk pregnancies.

Abortion, Eugenic↗
PubMed1989

Placenta percreta invading the urinary bladder.

The placenta, normally confined to the decidual lining of the uterine cavity, can in some circumstances invade the muscular wall of the uterus, a condition known as placenta accreta. Less common is placenta increta, in which placental cotyledons become intertwined with the muscular stroma of the uterus. Placenta percreta, in which the trophoblastic tissues penetrate the serosa of the uterus and may extend directly to adjacent structures, is even more rare and is potentially life-threatening. There have been only 10 reports of direct invasion of placenta percreta into the urinary bladder. We review these cases and report 3 recent patients, one of whom was diagnosed pre-operatively by ultrasonography.

Adult↗
PubMed1989

Twin-twin transfusion syndrome: sonographic findings.

Twin-twin transfusion syndrome (intrauterine parabiotic syndrome) is a potentially serious complication of monochorionic twinning. The frequency of fetal and neonatal death and perinatal morbidity is significantly higher than that in twin pregnancies uncomplicated by the syndrome. The authors present sonographic findings in ten cases of twin-twin transfusion syndrome proved by means of pathologic examination of the placenta and/or laboratory findings. The cases all involved diamniotic twins and covered a broad range of severity. Discordant fetal size and differing amniotic fluid volume in the two sacs were the most common findings. In more severe cases, hydrops of the recipient fetus and/or a "stuck" donor fetus was seen. Intrauterine death of one or both twins was observed in four cases. Familiarity with the sonographic patterns of the twin-twin transfusion syndrome can allow one to suggest the diagnosis in utero so that appropriate management can be undertaken.

Female↗
PubMed1989

Sexual impotence caused by vascular disease: diagnosis with duplex sonography.

We used duplex Doppler sonography to assess the hemodynamic function of the penis in patients with impotence to determine if there is arterial disease or if the veins are incompetent. The penis was scanned in the flaccid state, then again after erection was induced by intracorporal injection of papaverine. The diameter of each cavernosal artery was measured before and after injection and, by using Doppler sonography, the maximal systolic velocity in each cavernosal artery was measured. The Doppler gate was placed over the dorsal vein to detect any flow in that vein signifying venous leakage. The Doppler gate then was placed over the cavernosal veins in an attempt to detect cavernosal venous incompetence. Forty-five men with impotence were included in the study. In 39 patients, the cause of impotence was confirmed by other studies. The diameter of the cavernosal arteries and the increase in diameter of these arteries after induction of an erection were similar in all diagnostic groups. The peak systolic velocity, however, was decreased in patients with arterial insufficiency as compared with the velocity in normal subjects. In normal subjects, the mean peak velocity was 47 +/- 9 cm/sec; in patients with mild to moderate arterial insufficiency it was 35 +/- 16 cm/sec; in patients with severe arterial insufficiency it was 7 +/- 8 cm/sec. The difference in peak velocities between the right and left cavernosal arteries after papaverine injection (asymmetric arterial response) was significantly larger in patients with mild to moderate arterial insufficiency than in other diagnostic groups. Four patients with venous incompetence had detectable flow in the dorsal vein, but no flow could be detected with Doppler sonography in the cavernosal veins in any patients, including those who were proved to have significant cavernosal venous leaks. Our findings suggest that Doppler measurement of maximal systolic velocity in the cavernosal arteries after papaverine injection is an accurate indicator of arterial function. Asymmetric flow in the cavernosal arteries also suggests some degree of arterial insufficiency. Diameters of the cavernosal arteries and their increase after injection are not predictive of arterial patency. Doppler sonography cannot show cavernosal venous leakage, but in some cases it can show dorsal venous incompetence.

Blood Flow Velocity↗
PubMed1989

Sonographic features of focal orchitis.

High-resolution sonography is a very sensitive imaging modality for detecting intratesticular pathology and is an accurate means of distinguishing intratesticular lesions (usually malignant) from extratesticular ones (usually benign). Unfortunately, there are no reliable sonographic criteria to distinguish testicular neoplasms from focal benign intratesticular lesions such as infarction, hemorrhage, or infection. We describe three cases of focal orchitis in which the sonographic features did allow a confident diagnosis of intratesticular infection. In each case a focal peripheral hypoechoic intratesticular abnormality was seen that was poorly defined or crescent-shaped, adjacent to an enlarged epididymis. The specific sonographic features suggest the diagnosis of focal orchitis and orchiectomy can be prevented. Rapid improvement (2 to 4 weeks) should be seen sonographically and in all cases the intratesticular lesions should be followed to complete resolution.

Adult↗
PubMed1988

The diaphragm: anatomic, pathologic, and radiologic considerations.

The diaphragm, by virtue of its complex anatomy and multiple ligamentous connections to both thoracic and abdominal structures, is more than a simple partition between the chest and abdomen. Cross sectional images of the diaphragm and peridiaphragmatic processes can be confusing unless the radiologist is aware of the normal structure of the diaphragm, its attachments to the body wall, and the multiple ligaments that attach to the diaphragm.

Adult↗