Biomedical subjects
Publications and source records attributed to Z Heyman.
Fishbones are among the commonest foreign bodies lodged in the cervical esophagus. A small percentage of them will penetrate the esophageal wall and will be found either intra- or extraluminally. Migration of esophageal foreign bodies to the thyroid gland, and presentation as a mass, is extremely rare. We present such a case and review the relevant literature.
Intussusception of the colon initiated by a malignant tumor is an extremely rare occurrence during pregnancy. The nonspecific presenting symptoms may be attributed to the pregnancy itself, making diagnosis difficult. We report a case in which the use of magnetic resonance imaging led to prompt diagnosis.
Twenty-three pregnancies with fetuses at risk for pulmonary hypoplasia were studied weekly until delivery. The amount of time spent in fetal breathing activity was recorded under controlled conditions during 1 h using real-time ultrasound. An amniotic fluid index was determined. The clinicians and the pathologist were unaware of the ultrasound findings. Eight of 23 fetuses did not breathe at the last ultrasound examination. Three babies died of pulmonary hypoplasia and two of these showed fetal breathing before birth. The three deaths were associated with rupture of the membranes at less than or equal to 20 weeks gestation and of greater than or equal to 44 days duration. One infant developed bronchopulmonary dysplasia. The amniotic fluid index in these four pregnancies was low and the newborn infants had limb contractures. Chorioamnionitis/funisitis was noted in 13 placentas. Eight fetuses were assessed for fetal breathing within 2 days of birth. The lack of fetal breathing had sensitivity, specificity, positive and negative predictive values of 0.75 for chorioamnionitis/funisitis. In this pilot study the absence of fetal breathing was of no value in predicting lethal pulmonary hypoplasia, but was related to chorioamnionitis/funisitis. We recommend further studies of fetal breathing in relation to fetal/neonatal infections.
Aminophylline is used to treat apnoea and to facilitate weaning from assisted ventilation in preterm infants. Aminophylline is thought to increase respiratory drive centrally. We performed a randomized controlled double-blind study to determine if aminophylline increases the excursions of the diaphragm indicating a possible direct peripheral effect. Twenty-two neonates were randomized to treatment with intravenous aminophylline (n = 11) or to no treatment (n = 11). An ultrasonographer, who was blinded to the group assignment, studied the diaphragmatic excursions using a real time sector scanner. The posterior one-third of the right hemidiaphragm was localized and M-mode was used to record the diaphragmatic excursions on paper. The neonates were studied in an awake but quiet state. Aminophylline resulted in an increase (43%) in the excursions of the diaphragm (p = 0.012) with no change in respiratory rate or pCO2. These findings indicate that aminophylline had a measurable effect on the diaphragmatic motion. Further studies combining this technique with other techniques are needed to determine if the main effect of aminophylline in the prevention of apnoea is mainly central or peripheral.
The authors present a novel ultrasonic amplitude loss technique, using image processing techniques and designed for computation of local attenuation estimates. Three different estimation approaches were evaluated: the extended Prony, the maximum likelihood, and the least squares approaches. The latter two approaches were found to result in a much higher estimation error than that observed for the Prony method. The attenuation values in the normal population (49 subjects) were 0.44 +/- 0.03 dB/MHz/cm. Three hundred sixty-seven liver scans from 266 patients were evaluated. Hodgkin's lymphoma patients with liver involvement had attenuation values of 0.22 +/- 0.07 dB/MHz/cm. Low attenuation values also were observed for four patients with viral hepatitis (0.31 +/- 0.08 dB/MHz/cm). The detectability of other disease states was not increased by these global attenuation estimates; however, the results demonstrate possible potential uses for the proposed technique for the diagnosis of diffuse liver disease.
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This paper presents a novel technique for creating images of local tissue attenuation. The original conventional B scan is traversed, one pixel at a time. In the vicinity of each pixel, a uniform area is determined and average attenuation is computed utilizing an extended modified Prony approach. B scans of tissue mimicking phantoms and in vivo human liver scans are used in order to illustrate the performance of the proposed algorithm. The results show good agreement between estimated and known attenuation values. Clinical studies demonstrate significant potential of the proposed technique, in particular for diagnosis of diffuse liver disease.
Preoperative measurements of the thicknesses of pigmented skin lesions by high-resolution sonography have been studied. Fourteen nevi and 15 malignant melanomas were examined and their thicknesses compared with those measured on both paraffin and frozen sections. Linear regression coefficients of r2 = 9.22 and r2 = 9.23, respectively, were found. This good correlation suggests that sonography may be of value as a guide in predicting prognosis and in determining the proper course of treatment for patients with malignant melanoma.
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The indications, technique and results of percutaneous drainage in 20 patients with abscesses and other fluid collections are presented. Special emphasis is placed on the complementary use of ultrasound and computed tomography and the relative indications for the use of each. Of the 20 patients, 5 had hepatic abscesses, 7 had subphrenic or subhepatic abscesses, 3 had pancreatic pseudocysts and the remaining 5 had loculated fluid collections in either the abdomen or chest.
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Sonographic and radionuclear studies of the liver were performed in 68 patients admitted for suspected hepatic lesions. In 58 (85%) both studies gave similar findings. In 29 further investigations were required for accurate diagnosis. The ultrasonographic study was accurate in 97% and the radionuclear study in 72% while the two studies together achieved an accuracy of 89%. Sonographic study of the liver may in some cases indicate the consistency of the lesion (solid or fluid filled), which is of great clinical importance. However, hepatic nuclear scan is simple and available in most medical centers, making it the procedure of choice for evaluating space-occupying lesions of the liver.
Twenty children with suspected hypertrophic pyloric stenosis were studied by sonography. The thickened pyloric muscle is seen as an anechoic mass 1.5 cm or more in diameter, with strong central echoes. Of the 16 infants with a pyloric mass of 1.5 cm or more, 15 underwent surgery and the diagnosis was confirmed. In four patients with a pylorus less than 1.5 cm, the diagnosis of pyloric stenosis was excluded and all were discharged without surgery. Real-time scanning is useful in localizing the pylorus and in demonstrating lack of passage of gastric content across the narrowed pyloric canal.
Experience with the use of ultrasound for investigating hydatid disease of the abdomen is reported. The presence of daughter cysts within the parent cyst gives a pathognomonic sonographic picture, whether the cyst is single or multiple. The presence of single cysts without daughter cysts is still a diagnostic problem, unless calcification is seen. Associated secondary infection changes the picture to one of a nonspecific abscess, and only the presence of additional cysts can give a clue about the etiology.
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The sensitivity, specificity, and positive and negative predictive values for ultrasound estimation of fetal chest circumference in relation to autopsy-proven pulmonary hypoplasia are described in 58 singleton pregnancies at risk (39 with associated preterm premature rupture of the membranes at 30 weeks' gestation or less and of 12 or more days' duration, and 19 with associated anomalies). The ultrasonographic diagnosis of pulmonary hypoplasia was based on values at or below the lower limit of the 95% confidence intervals (for predicting a future observation) for normal pregnancies for each of the following tests; chest circumference in relation to gestational age and to femur length, for the chest circumference to abdominal circumference ratio and for a combination of the three measurements. At necropsy, the diagnosis of pulmonary hypoplasia was based on lung weight to birthweight ratio or radial alveolar counts. Pulmonary hypoplasia was diagnosed in 16 cases at autopsy. The clinicians and the pathologist were blinded to the ultrasonographic measurements. All tests performed well with a sensitivity of 0.55 to 0.80, specificity of 0.90 to 1.00, positive predictive value of 0.80 to 1.00, negative predictive value of 0.87 to 0.91, and an overall accuracy of 0.87 to 0.91. We conclude that ultrasound measurement of fetal chest circumference is of value with regard to the management of pregnancies at risk for lethal pulmonary hypoplasia.