Search PubMed⌕ Search

Biomedical subjects

A Monteagudo

Publications and source records attributed to A Monteagudo.

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

Sonographic assessment of chorionicity and amnionicity in twin pregnancies: how, when and why?

During the first trimester, chorionicity can be assessed as early as five weeks post-conception, but a reliable detection of amnionicity cannot be performed before the 8th week when the amnion can be clearly imaged. The late second and third trimesters twin pregnancies are a true challenge to the imaging specialist because the detection of chorionicity and amnionicity has to rely upon sonographic clues, such as placenta location, fetal gender, membrane origin, thickness, and layer. Sonographic methods used to determine chorionicity and amnionicity in twins can be extrapolated to any multifetal pregnancy, regardless of the number of fetuses present.

Amnion↗
PubMed1998

Color flow-directed Doppler studies of ovarian masses. Computer analysis.

OBJECTIVE: To determine if analyzing the entire color Doppler image (CDI) pulse wave of an ovarian mass can improve the ability to predict its histopathology. STUDY DESIGN: The CDI of 42 histopathologically diagnosed adnexal masses were retrospectively analyzed. Using an image analysis software program, the following parameters were calculated: area under the curve, compactness, Feret diameter, perimeter, shape factor and width of the waveform. Using an automated curve-fitting software program, the up and down slopes were processed separately for the optimal equation and coefficient for each slope. Two computerized neural networks were created, both consisting of an input layer, one hidden layer and an output layer of three neurons: benign, borderline and malignant. The first network contained two input neurons: pulsatility index (PI) and resistance index (RI). The second network contained 10 input neurons consistent with the shape and slope parameters calculated. The coefficient of determination (R2) was determined for each network. RESULTS: The neural network utilizing RI and PI failed to train (1,397 runs, 67,056 facts, R2 = 0.59, 0.12 and 0.43 for benign, borderline and malignant masses, respectively). The network using the 10 calculated parameters achieved an R2 of 0.96 after 685 runs and 27 facts. CONCLUSION: Analyzing the CDI studies of ovarian masses, using the entire pulse wave, improved the ability to differentiate between their benign, borderline and malignant histopathology.

Diagnosis, Differential↗
PubMed1997

Transvaginal color Doppler sonography of the ureteral jets: a method to detect ureteral patency.

OBJECTIVE: To evaluate the feasibility of the detection of ureteral jets into the bladder in obstetric-gynecologic patients using transvaginal color Doppler ultrasound. METHODS: Fifty-two women were recruited and categorized into four groups: 1) 20 normal nonsurgical, 2) 17 post-cesarean delivery, 3) 12 post-total abdominal hysterectomy, and 4) three with only one functional kidney or ureter. In the first three groups, transvaginal color Doppler sonography was used to evaluate the time to detection of the first jet and the number of jets in 5 minutes bilaterally. In the last group, the presence or absence of the jet was documented only on the functional side. Statistical analysis was performed using Student t test and analysis of variance followed by Tukey honestly significant difference. RESULTS: Urine jets could be detected bilaterally in all women except for those with only one functional kidney (accuracy 100%). Time to detection of the first jet did not differ significantly in the nonsurgical, cesarean, or hysterectomy patients on either the right side (P = .07) or the left side (P = .43). The total number of jets was similar in the nonsurgical and cesarean patients, but was significantly lower in the hysterectomy group (right side P = .006; left side P = .004). In the women with one functional kidney, the normal side was identified in all cases. CONCLUSION: Transvaginal color Doppler sonography is a simple, accurate technique that can be used to evaluate ureteral jets into the bladder in women. The length of time to detection of the first jet is not affected by the postoperative status. Fewer jets should be expected in women who have undergone hysterectomies. This method should be used when ureteral integrity is in question, especially after surgery.

Adult↗
PubMed1997

Development of fetal gyri, sulci and fissures: a transvaginal sonographic study.

We aimed to determine the feasibility of imaging specific sulci, gyri and fissures using transvaginal sonography and to correlate their first sonographic recognition with gestational age. Retrospectively, 262 fetal brain scans were analyzed from a total of 337 scans. Scans were selected if any of the following structures were seen: in the coronal plane the lateral, callosal and cingulate sulcus and gyrus; in the median plane the parieto-occipital and calcarine fissures, and the cingulate gyrus and sulcus; and, in an oblique section, the lateral sulcus. The gestational age at which the fissures, sulci and gyri were first imaged was recorded and subsequently compared with similar anatomical studies from the literature. It was possible to identify all the targeted structures. The gestational ages at which the structures were first imaged were: the callosal sulcus, from 14 weeks; the lateral sulcus, from 18 weeks; the parieto-occipital sulcus and calcarine fissure, from 18 weeks; and the cingulate gyrus, from 26 weeks. We concluded that the developmental maturation of the normal fetal brain follows a predictable timetable, and that this maturation can be grossly followed with sonography. The sonographic recognition of the fissures, gyri and sulci lagged behind the observations by anatomical studies. The greatest discrepancy was the first appearance of the cingulate gyrus which, in the anatomical studies, could be seen by 18 postmenstrual weeks and, in our study, was seen after 26 postmenstrual weeks. The one exception was the callosal sulcus, which was first seen at 14 postmenstrual weeks in both the sonographic and anatomical studies. In conclusion, the recognition of specific structures of the cortical map is possible. Sonography may be used to image the developing cortical surface.

Brain↗
PubMed1997

Ovarian steroid cell tumors: sonographic characteristics.

The goal of the gynecologist is to detect ovarian tumors in their earliest stages. Small virilizing tumors, which barely affect the size of the ovaries, are such lesions. Since the introduction of transvaginal sonography it is technically possible to detect small intraovarian neoplasms. Three cases of virilizing steroid cell tumors in postmenopausal women with ovarian volumes just exceeding the normal sizes for age are presented. High-frequency transvaginal ultrasound and color Doppler studies to measure flow parameters were used. These small tumors had different echogenicity from the surrounding ovarian tissue and two had low impedance-to-flow values. Gray-scale transvaginal sonography combined with color Doppler studies can make the diagnosis of small steroid cell tumors easier and, at times, better than other, more costly imaging modalities.

Aged↗
PubMed1997

Transvaginal gray-scale imaging of ureteral jets in the evaluation of ureteral patency.

We have previously reported on the value of transvaginal color Doppler evaluation of the ureteral jets to confirm ureteral patency. In this study, we attempt to validate the simple and widely available gray-scale ultrasound technique to perform the same task. Fifty consecutive patients without a history of urinary complaints were recruited. The presence or absence of the right and left ureteral jets was registered using gray-scale imaging, comparing the technique to color Doppler as the 'gold standard'. The time to the detection of the first jet as well as the total scanning time were documented for each side. The jets were seen with equal frequency on both the right and the left sides (34 observations each). In 24 patients, both jets were visualized. The median time to detection of the first jet was 47 s (range 34-79 s) for the right jet and 53 s (36-84 s) for the left jet (p = 0.42). The median total scanning time was 176 s (139-259 s). Gray-scale imaging was associated with a sensitivity of 68% and a positive predictive value of 100%. Although color Doppler results may be more attractive because of their impressive color-coded appearance, the major disadvantage of this technique is that it requires sophisticated and costly equipment. Transvaginal gray-scale imaging is a reliable and useful test for the detection of ureteral jets in the bladder. It can be used as a first-line diagnostic tool, particularly in settings where color Doppler is not available. Its benefits include safety, low cost, convenience and simplicity. With a positive predictive value of 100%, this test may be used in the postoperative patient, especially when ureteral patency is in question.

Adolescent↗
PubMed1996

Transvaginal sonographic detection of adducted thumbs, hydrocephalus, and agenesis of the corpus callosum at 22 postmenstrual weeks: the masa spectrum or L1 spectrum. A case report and review of the literature.

Prenatal diagnosis of non-chromosomal syndromes relies, among others, on the detection of specific morphological findings. In rare syndromes the index case may not be prenatally diagnosed but subsequent pregnancies may benefit from early diagnosis. In this article we discuss the clinical spectrum of an X-linked hereditary disease which contains hydrocephalus, congenital agenesis of the corpus callosum, adducted thumbs, shuffling gait, aphasia, mental retardation, and at times other associated findings. The purpose of this case report is to describe the prenatal sonographic findings of a fetus affected with adducted thumbs, hydrocephaly, and agenesis of te corpus callosum. The patient was referred at 22 1/2 weeks' gestation for prenatal diagnosis. Ultrasound revealed a male fetus with dilatation of the lateral ventricles and partial agenesis of the corpus callosum. The fetal hands showed the thumbs to be fixed in a flexed-adducted position. These findings were consistent with the MASA spectrum (mental retardation-aphasia-shuffling gait-adducted thumbs) present in the older brother. The patient elected to terminate the pregnancy and autopsy confirmed the sonographic findings. In conclusion, prenatal sonography, especially the presence of adducted thumbs, allowed prenatal diagnosis of the second affected child with the MASA spectrum in this family. This morphology-based approach becomes feasible between postmenstrual weeks 15 and 20. Prior to this gestational age, the diagnosis should rely on molecular biology tests.

Agenesis of Corpus Callosum↗
PubMed1996

Can a "snapshot" sagittal view of the cervix by transvaginal ultrasonography predict active preterm labor?

OBJECTIVE: Our purpose was to test the hypothesis that wedging of the cervical internal os determined by transvaginal ultrasonography is associated with premature labor and delivery. STUDY DESIGN: Seventy patients admitted to the hospital for threatened preterm labor were evaluated by transvaginal ultrasonography before institution of therapy. Bivariate and logistic regression analyses were performed to determine the variables that made a significant contribution to the prediction of preterm delivery. RESULTS: Preterm delivery was significantly associated with the presence of cervical wedging, as noted on cervical scan, and with short cervical length. A history of previous preterm delivery was of marginal significance as a predictor of preterm delivery (p=0.09). Preterm delivery was not significantly correlated with age, previous voluntary termination of pregnancy, gestational age at the time of study, previous normal spontaneous vaginal delivery, or tocolytic therapy. Use of wedging as a diagnostic test for the prediction of preterm delivery yielded a sensitivity of 100% a specificity of 74.5%, a positive predictive value of 59.4%, and a negative predictive value of 100%. CONCLUSION: The presence of wedging and shorter cervical length was suggestive of true preterm labor requiring aggressive management. A transvaginal ultrasonographic "snapshot" view of the cervix seems to be a more reliable method to evaluate the cervix in patients with threatened premature labor than are uterine contractions alone.

Adult↗
PubMed1996

A 'potentially safer' route for puncture and injection of cornual ectopic pregnancies.

Puncture and injection (usually by methotrexate) of ectopic pregnancies are relatively new modalities of treatment. Lately, these have been applied to cornual ectopic pregnancies. We describe here a proposed transvaginal ultrasound-guided puncture route, leading the needle into the cornual ectopic pregnancy, first traversing the myometrium and approaching the gestational sac from the medical aspect. After extracting the needle, there is potentially less chance for rupture and bleeding. In six of the seven injected cornual pregnancies, this technique was used without complication. The only one punctured from the lateral aspect bled and required laparoscopic intervention. This technique may enable the wider use of this treatment modality by lowering the complication rate caused by bleeding at the puncture site.

Cervix Uteri↗
PubMed1996

Transvaginal fetal neurosonography: standardization of the planes and sections by anatomic landmarks.

Owing to the limited mobility of the transvaginal probe within the vagina and the introitus, it is virtually impossible to obtain coronal and sagittal sections that are anatomically comparable to those obtained in anatomic sections, computed tomography or magnetic resonance scanning. The aim of this paper is to standardize the neurosonographic images of the fetal brain and develop a nomenclature that more closely reflects the true anatomic sections. A retrospective review of 347 fetal neuroscans was performed. With the use of specific landmarks within the fetal brain, new nomenclature was developed. The scans were divided into the frontal, coronal and sagittal groups. Each group was subsequently further divided into three specific sections. The transvaginal sonographic images of the fetal brain radiate in a fan-like fashion from the anterior fontanelle; therefore the new proposed nomenclature more accurately describes the true anatomic sections.

Brain↗
PubMed1996

Prenatal diagnosis of the split hand anomaly: how early is early?

A case of split hand anomaly detected by transvaginal sonography at 18 weeks of gestation is reported in which the diagnosis was difficult to establish. Different aspects of this pathology are discussed. Sonographic diagnosis of hand anomalies may be difficult to establish, even with experience. The ideal timing for the prenatal detection of this anomaly remains to be determined.

Adult↗
PubMed1996

Autosomal dominant cataracts of the fetus: early detection by transvaginal ultrasound.

Cataracts are lens opacities that account for approximately 10% of blindness in children. We report on four consecutive pregnancies in a woman at risk for recurrent autosomal dominant cataracts in which extensive ultrasound studies were helpful in establishing the correct diagnosis. The normal appearance of the fetal lens is that of a ring with a central sonolucency, but in cases of cataracts the lens appears hyperechogenic to various degrees. In the first pregnancy, normal lenses were seen at 15 postmenstrual weeks and, at birth, the baby girl had normal lenses. In the second pregnancy, the male fetus was affected by a left-sided cataract and a right-sided anophthalmia which were diagnosed at 16 postmenstrual weeks. The histological examination of the specimen from the aborted fetus correlated with the sonographic diagnosis. The third pregnancy, also a male fetus, had bilateral cataracts suspected at 14 weeks, but the final diagnosis was made at 19 weeks and confirmed at 21 weeks. The couple opted to terminate the pregnancy and the histology confirmed the presence of congenital cataracts. In the fourth pregnancy, we diagnosed asymmetry of the orbital sizes and bilateral cataracts at 15 weeks. In conclusion, the diagnosis of fetal cataract from the second trimester of pregnancy is possible and imaging of the fetal lenses should be part of the routine anatomical survey. Since the exact onset of fetal cataracts is uncertain at present, in cases at risk, serial sonograms may be indicated.

Adult↗
PubMed1996

Successful transvaginal ultrasound-guided puncture and injection of a cervical pregnancy in a patient with simultaneous intrauterine pregnancy and a history of a previous cervical pregnancy.

Cervical pregnancy is a rare type of ectopic pregnancy. A recurrent cervical pregnancy in conjunction with a viable intrauterine pregnancy is an even rarer event. We present a case in which a recurrent cervical pregnancy was treated by selective reduction using an injection of potassium chloride guided by transvaginal sonography. The intrauterine gestation was delivered at a gestation of 34 weeks and 4 days by Cesarean section. Subsequently, the patient was treated with intramuscular methotrexate with a prolonged, but complete, resolution of the cervical pregnancy.

Abortion, Legal↗
PubMed1996

Scanning techniques in obstetrics and gynecology.

Using the appropriate scanning techniques and knowing the advantages and disadvantages of ultrasound equipment, the clinically useful pictures that enable better care of the obstetric and gynecologic patient can be generated. The extra advantage of applying the best possible scanning technique may enable the clinician or the imaging specialist to arrive at the correct diagnosis, despite problems created by anatomic circumstances, such as body habitus. The widespread use of ultrasound in general and transvaginal sonography in particular substantially has changed obstetric and gynecologic practice. High frequency transducer probes enable the creation of a crisp detailed picture that facilitates a more accurate and faster diagnostic procedure. Transvaginal sonography should be considered the first choice laboratory tool in the diagnosis of an increasing number of obstetric and gynecologic entities.

Female↗
PubMed1996

Use of transvaginal sonography in the evaluation of endometrial hyperplasia and carcinoma.

Published studies relating to the use of transvaginal sonography (TVS) in the evaluation of endometrial hyperplasia and carcinoma were reviewed. Approximately 80 percent of all curettage procedures performed for postmenopausal bleeding result in benign diagnoses, therefore, if a noninvasive modality such as TVS can be accurately used to determine endometrial thickness measurements below which pathology is less likely, sampling may be avoided. The largest study evaluating endometrial measurements in postmenopausal women with bleeding, known as the Nordic trial, found that for a cut-off value of < or = 4 mm, 96 percent sensitivity and 68 percent specificity was achieved. Another study evaluated endometrial echomorphology in addition to measurement and found that the combined approach improved the predictability of pathologic findings. TVS may also be used to assess the depth of myometrial invasion in patients already diagnosed histologically with endometrial carcinoma. Although MRI is considered the established tool in the presurgical evaluation of the patient with carcinoma, TVS was found to perform only slightly less accurately than MRI. The published studies regarding TVS and/or MRI are reviewed. Finally, the use of TVS in conjunction with a new modality, sonohysterography, in the evaluation of patients on tamoxifen therapy, is discussed. Although the published cut-off values for endometrial thickness measurements do not apply to this group of patients, a procedure whereby sterile saline is injected into the uterine cavity, via a thin catheter, provides additional information regarding endometrial contours. Once the procedure is performed, the supposed complex endometrial echo seen on TVS is often found to actually be located in the subendometrial myometrium and the endometrium itself is thin and regular. The role for TVS is well established in the search for endometrial hyperplasia and carcinoma, as well as evaluating the presence of myometrial invasion once the diagnosis is made.

Diagnosis, Differential↗
PubMed1996

Ultrasound-guided transvaginal procedures.

Transvaginal ultrasound revolutionized the practice of obstetrics and gynecology in the past decade. Its 'port of entry' was its application in the diagnostic, as well as the technical and therapeutic aspects, in the reproductive aspects of infertility. This review summarizes the advances made by the continual improvement of equipment, and the ingenious use of different punctures guided by transvaginal sonography in the important area of reproductive technologies.

Female↗
PubMed1995

Vibratory acoustic stimulation and fetal gasping.

OBJECTIVE: Vibratory acoustic stimulation (VAS) has been used to shorten the duration of antepartum fetal heart rate monitoring. Questions have been asked regarding the possible effects of VAS on the fetus. VAS was used to investigate whether the acute effect of VAS is associated with gasping in the normal fetus. STUDY DESIGN: Thirty-seven normal patients at 37-42 weeks' gestation with singleton fetuses were studied. All had normal amniotic fluid volume on ultrasound. These 37 subjects had a five-minute baseline sonographic assessment of fetal breathing and body movements. A fetal gasp was defined as an isolated, slow, irregularly occurring, deep, inspiratory-type movement, or series of them, of the chest and abdomen. Three-second VAS was then delivered with an artificial larynx placed directly over the fetal head. Fetal breathing, body and gasping movements were assessed at the time of this stimulus. RESULTS: A significant increase in fetal body movements (P < .001), a significant decrease in fetal breathing (P < .003) and absence of gasping movements were noted. CONCLUSION: The results suggest that gasping does not occur in response to VAS in the normal, term fetus.

Acoustic Stimulation↗