Biomedical subjects
Publications and source records attributed to R Silverman.
In an effort to evaluate the efficacy of measuring abdominal circumference with real-time ultrasound, 53 patients were scanned with both contact scanning and linear array real time. Image measurements were made blindly from both types of equipment. Abdominal circumference measurements with real time compared favorably with those obtained from contact images (r = +0.984).
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With ultrasound one can outline fetal kidneys and evaluate intrarenal anatomy. In an effort to determine how fetal kidney size varies with gestational age, 89 patients not at risk for fetal kidney disease and whose pregnancies resulted in a normal outcome were studied from 12 weeks until term. Kidney diameter measurements were taken and found to increase linearly until term. Kidney circumference (KC) measurements were made and compared to abdominal circumference (AC) measurements at the level of the umbilical vein by means of a KC/AC ratio. This ratio was found to remain constant throughout pregnancy (0.27 to 0.30). In addition, three patients at risk for congenital kidney disease were studied and the fetal kidneys were found to have KC/AC ratios approximately 6 S.D. (KC/AC ratio greater than or equal to 0.45) above the normal mean. The diagnosis was confirmed by autopsy in two cases. These data are presented for reference in evaluating patients in the second and third trimester whose fetuses are at risk for kidney abnormalities.
With high-resolution ultrasound equipment, it is now possible to diagnose certain fetal anomalies in the third trimester and in some cases before the twentieth week of gestation. During a 27 month period 2,548 ultrasound scans were performed in high-risk patients. An anomaly was diagnosed in 10 of 122 second-trimester patients who were at risk for recurrent fetal defects. Fetal deformity was also found in 26 third-trimester patients. Of the 2.8% of patients found to have polyhydramnios 18% were associated with various types of anomaly. With ultrasound it was possible to examine internal fetal anatomy and to identify abnormalities of the fetal cranium, spine, chest, abdomen, and limbs. These anomalies are reviewed here in detail. Based on ultrasonically derived information, second-trimester patients can be offered information concerning the status of their fetuses at risk genetically and physicians can better manage third-trimester patients with diagnosed fetal deformities.
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When immunoreactive human parathyroid hormone (hPTH), extracted by three different solvents (20% acetone in 1% acetic acid, 8 M urea, or normal saline) from parathyroid glandular tissue was subjected to Sephadex G-100 gel filtration and immunoassay using two different antisera (273 and C-329), four distinct fractions were observed. The first (I), a void volume peak, was detected by both antisera with similar immunoreactivity, as was a second (II), which had the elution and sedimentation properties of highly purified bovine parathyroid hormone (bPTH); a third (III) eluted between [(125)I]growth hormone and [(125)I]insulin, sedimented with the velocity of a molecule of approximately 6,000 mol wt, and was detected primarily by antiserum 273; a final fraction (IV), detected primarily by C-329, eluted just prior to [(125)I]insulin. The elution profiles of the acetone-acetic acid and 8 M urea extracts were similar and contained fraction II as their major component. In saline extracts, however, fraction III predominated. Three fractions, having gel filtration and immunologic characteristics similar to fractions II, III, and IV, respectively, of saline glandular extracts, were detected in the plasma of patients with both primary (adenomatous or carcinomatous) and secondary hyperparathyroidism. The predominant component in every plasma was the intermediate fraction that, like III, was detected primarily by antiserum 273, while the least abundant form was consistently the final fraction, detected primarily by antiserum C-329. The first fraction, like II, was detected with about equal potency by both antisera and had an elution volume on Sephadex corresponding to that of intact bPTH. It bore a reciprocal relationship to serum calcium and disappeared from the plasma of a uremic patient during calcium infusion or following parathyroidectomy with a half-time of no more than 20 min. This component therefore probably represents biologically active hormone. The intermediate and final fractions had turnover times in the plasma of a uremic patient more than 100 times greater than the active form, remained elevated even in the presence of post-parathyroidectomy hypoparathyroidism in this patient and were presumed to be biologically inactive. The ratio of biologically inactive fragments to the active form was greater in secondary hyperparathyroidism. The evidence presented favors a glandular origin for the fragments. Comparison of hormonal assays with the two antisera reveals a striking advantage in the preoperative diagnosis of primary hyperparathyroidism with antiserum 273 that is due to the enhanced sensitivity occasioned by its detection of a biologically inactive as well as the biologically active hormonal form.
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The potential of new high-field-strength magnetic resonance (MR) imaging sequences to evaluate bowel disease was investigated and compared with computed tomographic (CT) studies. Thirty-two patients were studied, 14 with known or suspected gastrointestinal tumors and 18 with known or suspected bowel inflammatory conditions. T1-weighted fat-suppressed spin-echo and breath-hold FLASH (fast low-angle shot) images were obtained before and after intravenous injection of 0.1 mmol/kg gadopentetate dimeglumine. Pathologic confirmation was obtained by biopsy (n = 18), surgical excision (n = 8), or endoscopy (n = 6). CT and MR images were analyzed separately in a prospective fashion and reviewed by consensus. Information from CT and MR images was comparable in cases of confirmed bowel neoplasia. CT scans had better spatial resolution, while fat-suppressed gadolinium-enhanced MR images had better contrast resolution. In the 18 cases of bowel inflammation, CT scans showed concentric wall thickening in 16, while MR images showed concentric wall thickening in 14 and increased contrast enhancement in 17. Contrast enhancement was better appreciated on fat-suppressed images than on FLASH images. The results suggest that MR imaging may play a role in the evaluation of bowel disease.
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