Biomedical subjects

M E Pasto

Publications and source records attributed to M E Pasto.

28 records · Page 2Linked to original sources

PubMed1984

Intraoperative ultrasound examination of the brain: possible pitfalls in diagnosis and biopsy guidance.

The use of ultrasound during surgical procedures is frequently beneficial for both demonstration and diagnosis of various pathologic conditions. In the neurosurgical suite, localization of subcortical brain tumors is easily accomplished with real-time imaging. The depth and size of the tumor are easily assessed, and the relationship of the lesion to adjacent normal structures ascertained. However, there are pitfalls that may result in diagnostic inaccuracies during the evaluation of abnormalities. These include artifacts, use of inappropriate equipment, and poor technique. These problems are illustrated and discussed.

Adolescent↗

PubMed1984

The inaccuracy of total uterine volume measurements: sources of error and a proposed solution.

Inaccuracies in total intrauterine volumes calculated using the prolate ellipse equation have been reported. No previous study has examined all the sources of error. In this study, a comprehensive approach was undertaken. Measurements were obtained from scans of the pregnant uterus in the prone position using an automated water-path scanner (Octoson) and in the supine position using standard static B-mode scanners. Several conclusions could be drawn: 1) From the Octoson prone scans, uterine volumes obtained using the prolate ellipse formula were markedly different from the true uterine volumes obtained by the summation of stepped areas. This showed that the prolate ellipse formula was inaccurate. 2) From the static supine scans, many observer inconsistencies were found in uterine volumes obtained from the prolate ellipse formula. This made the prolate ellipse formula unreliable. 3) Previously published graphs calculated from the prolate ellipse equation, comparing fetal age with total intrauterine volume, were found to vary accuracy, presumably as a result of 1 and 2. A more accurate approach is proposed. Using the outer uterine wall as the boundary, the stepped area-to-volume values of transverse scans taken at 3-cm intervals were found to closely approximate true volumes, with an average error of only 3.5 per cent. Since these measurements encompass the intrauterine contents and the myometrium, it is suggested that the term "total uterine volume" be used instead of "total intrauterine volume."

Amniotic Fluid↗

PubMed1984

Total uterine volume: a new graph and its clinical applications.

The prolate ellipse formula has been shown to be inaccurate and inconsistent in the calculation of total uterine volume. The stepped area-to-volume technique has proven to be both accurate and consistent and provides a value equal to the true uterine volume. When these true volumes were plotted on previously published graphs of total uterine volume derived from the prolate ellipse formula, the graphs were found to be inaccurate. New graphs based on normal values have been constructed, comparing total uterine volume with both biparietal diameter and average gestational age. When 26 abnormal values were plotted on the total uterine volume versus biparietal diameter graph, almost all fell outside the 90 per cent confidence limits. Seven of the abnormal value were from fetuses found to have growth retardation. Six of these cases, including two not appreciated either clinically or ultrasonographically, were detected by this method. The stepped area-to-volume technique should allow reconsideration of the total uterine volume concept and aid in the detection of the subtle changes in uterine size.

Amniotic Fluid↗

PubMed1983

Mesenteric chylous (lymph-containing) cyst.

Mesenteric cysts are uncommon entities and chyle (lymph)-containing cysts are the rarest of this group. A case report of a chylous cyst with CT demonstrating unique fat and soft tissue fluid-fluid levels is presented.

Chyle↗

PubMed1983

The Kimray-Greenfield filter: evaluation by duplex real-time/pulsed Doppler ultrasound.

The Kimray-Greenfield filter is a wire cage which is inserted into the inferior vena cava (IVC) to prevent thrombi originating in pelvic and leg veins from embolizing to the lungs. Duplex real-time/pulsed Doppler ultrasound was used to evaluate placement and function in 38 patients (46 examinations). Real-time examination successfully identified the IVC and filter in 89% of cases. Pulsed Doppler studies demonstrated flow above and below the filter in 76%, accurately predicting normal flow in most cases. In 4 patients, Doppler scans revealed little or no flow distal to the filter; contrast cavograms confirmed obstruction secondary to thrombosis. This appears to be an accurate, noninvasive method of assessing postoperative reliability of the Kimray-Greenfield filter.

Adolescent↗

PubMed1983

Polyorchidism diagnosed preoperatively by ultrasonography.

Polyorchidism, or multiple testes, is a rare condition that has been referred to in both medical literature and mythological folklore. Curious attributes have been ascribed to men with this condition, including supposed increased sexual prowess and virility. In the medical literature, the examples of supernumerary testicles have demonstrated only one additional testis. The first proven case of an extra testicle was by Lane, in 1895. Boggon reviewed 11 additional cases in 1933, and numerous other cases have been reported since then. To date, there has not been a preoperative ultrasonographic study that adequately describes this phenomenon.

Adolescent↗

PubMed1983

Ultrasonographic findings in placenta increta.

Placenta increta, invasion of the myometrium by normal placental (chorionic) villi, can be life-threatening to a mother at delivery. In two reported cases of pathologically proven placenta increta, the abnormal areas were retrospectively identified on ultrasonographic images. In both cases, there was consistent focal obliteration of the hypoechoic retroplacental zone by either tissue of echogenicity similar to that of the normal placenta or tissue of slightly decreased echogenicity. This was found to represent extension of the villi through the decidua basalis into the myometrium. The spectrum of non-malignant invasive placentas and the specific ultrasonographic findings that should allow prospective diagnosis are discussed.

Decidua↗

PubMed1983

The role of diagnostic ultrasonography in varicocele evaluation.

Twenty-one patients with the clinical diagnosis of varicocele were evaluated with static and superficial organ scanners. The sonogram was able to image the dilated scrotal veins in all of these cases. The small, clinically subtle varicocele could be demonstrated only with high-resolution, dedicated real-time small-parts scanners, whereas larger lesions could also be imaged with B-mode contact equipment. Varicoceles are a well-documented cause of male infertility amenable to surgical treatment. From this study it is felt that ultrasonography can accurately detect varicoceles. It can be used as a screening procedure so that only those men requiring therapy need undergo more extensive and complicated diagnostic procedures.

Adult↗

PubMedDate not supplied

Duplex Doppler examination in renal disease: evaluation of vascular involvement.

Evaluation of renal disease and transplant rejection has been limited to excretory urography, nuclear isotope flow studies and other more invasive procedures. The B-scan ultrasound findings are often nonspecific. The development of duplex pulsed Doppler sonography has permitted evaluation of both arterial and venous flow. Duplex ultrasound studies in patients with a suspected diminution in renal function demonstrated the ability to delineate normal and abnormal flow, limiting the differential diagnosis, and in some cases actually documented an abnormality before gross pathologic changes became evident.

Adult↗

PubMedDate not supplied

Noninvasive diagnosis and follow-up of childhood renal vein thrombosis by ultrasound, Doppler, and renal scintiscan.

Childhood renal vein thrombosis (RVT) usually occurs in infants less than one year of age, and in recent years, more RVTs are diagnosed with the help of various diagnostic imaging modalities. RVT produces immediate physiologic, anatomic, and functional changes within the involved kidney or kidneys and these changes can be detected readily and noninvasively by Doppler ultrasound, ultrasound scan, and renal scintiscans. Childhood RVTs are associated with substantial morbidity, and the earlier the diagnosis and treatment, the better the prognosis. The most important factor in the diagnosis of childhood RVT is a high clinical index of suspicion. With a high degree of clinical suspicion, one can make the specific diagnosis of RVT using the noninvasive methods. Such methods can also be used for follow-up of patients with RVTs.

Child↗