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Biomedical subjects

S K Sargent

Publications and source records attributed to S K Sargent.

16 recordsLinked to original sources

Extralobar pulmonary sequestration receiving its arterial supply from the innominate artery.

Pulmonary sequestration is a rare bronchopulmonary foregut malformation, for which the arterial blood supply is usually derived from the descending thoracic or abdominal aorta. A 5-week-old infant is described with an extralobar pulmonary sequestration supplied by a large artery originating from the innominate artery, an arrangement only described once previously. Helical CT scan now makes arteriography unnecessary in the evaluation of these malformations.

Age Factors↗

The posterior approach to pyloric sonography.

Overlying bowel gas or gastric distension may occasionally hinder the sonographic diagnosis of hypertrophic pyloric stenosis. To address this problem, a novel approach for obtaining posterior views of the pylorus is reported. Utilizing this approach may decrease the incidence of nondiagnostic pyloric ultrasonography.

Age Factors↗

Hydrostatic balloon dilation of congenital esophageal stenoses associated with esophageal atresia.

It has been stated that congenital cartilage rings in the esophagus do not respond to dilation and should be resected. The authors report on 3 infants with congenital esophageal stenoses who were treated successfully with hydrostatic balloon dilation. Based on the appearance during dilation the authors believe that these stenoses were cartilage rings. The technique is described in detail. Balloon dilation is the treatment of choice for these patients. Resection should be reserved for those who do not respond to this form of therapy.

Catheterization↗

Sensitivity of prevertebral soft tissue measurement of C3 for detection of cervical spine fractures and dislocations.

A prevertebral soft tissue measurement exceeding 4 to 5 mm at C3 on a lateral spine radiograph is considered to be evidence of cervical spine injury. The objective of this study was to determine the sensitivity of the prevertebral soft tissue measurement at C3 in patients with proven cervical spine fractures or dislocations and to determine if this measurement correlates with the location or mechanism of injury. Consecutive patients 16 years of age or older who were admitted from July 1988 to June 1995 to a tertiary referral hospital with a discharge diagnosis of cervical spine fracture or dislocation were retrospectively studied. Patients were excluded if an interpretable lateral cervical radiograph taken within 24 hours of the injury was unavailable, medical records were unavailable or incomplete, the injury was caused by penetrating trauma or attempted hanging, or retropharyngeal air was present on the lateral radiograph. For each study patient, the earliest available lateral radiograph was obtained, and the prevertebral soft tissue measurement at the inferior aspect of C3 was recorded. All medical records and reports of imaging studies were reviewed. Two hundred thirty-two patients were identified and 21 were excluded, leaving 212 study patients. Injuries were classified as high (C1 to C2), low (C3 to C7), anterior, or posterior. For each patient the mechanism of injury was inferred from the fracture pattern according to established criteria. For all patients the sensitivity of a prevertebral soft tissue measurement at C3 of > 4 mm was 66% (95% confidence interval [CI] 59, 72). For C1 to C2 (n = 71) and C3 to C7 (n = 138) injuries, the sensitivities were 64% (95% CI 56, 78) and 64% (95% CI 56, 72), respectively. For anterior (n = 95) and posterior (n = 70) injuries the sensitivities were 64% (95% CI 54, 74) and 64% (95% CI 52, 75), respectively. There was no statistically significant difference in the prevertebral soft tissue measurement at C3 for high versus low injury, anterior versus posterior injury, or mechanism of injury. These results show that the prevertebral soft tissue measurement at C3 is an insensitive marker of cervical spine fracture or dislocation and does not correlate with the location or mechanism of injury.

Adolescent↗

Accuracy of prenatal sonography for detecting circumvallate placenta.

OBJECTIVE: We determined the accuracy of prenatal sonography for detecting placental circumvallation, a placental abnormality associated with increased fetal morbidity and mortality. MATERIALS AND METHODS: We analyzed 62 healthy pregnant (range, 18-36 weeks) patients with focused placental sonography for detection of morphologic abnormality using the published criteria for circumvallate placenta (irregular edge, uplifted margin, or placental sheet or shelf). Placental marginal sonograms were taken at 30 degrees intervals around the entire placental margin. Five experienced sonologists who were unaware of the pathologic findings independently reviewed the placental images and graded the placentas from 1 (definitely normal) to 5 (definitely circumvallate). Receiver operating characteristic (ROC) curves and area under the ROC curve were calculated for each reader. Gross and microscopic pathology was used as the gold standard for all cases. RESULTS: In the 62 patients, sonography revealed 49 normal placentas (79%), 12 partially circumvallate placentas (19%), and one completely circumvallate placenta (2%). ROC curves for the reviewers resulted in values for area under the curve ranging from .39 to .58. The sonologist who achieved the highest value for the area under the curve classified the 13 cases of proven circumvallation as one case of definite circumvallation, four cases as uncertain or equivocal, and eight cases as probably or definitely normal placentas. Of the normal placentas, 35% were graded as probably or definitely circumvallate by at least one sonologist. All sonologists misgraded the case of complete circumvallation as normal. CONCLUSION: Focused placental sonograms interpreted by experienced sonologists fail to detect the placental edge abnormality in most cases of circumvallation. In our study, 17 of 49 normal placentas were diagnosed as probably or definitely circumvallate by one or more observers. Our sonologists' interpretations of sonograms showed that complete circumvallation was difficult to assess. Although our study had a limited number of patients, the accuracy of sonography of the placenta for revealing circumvallation appears to be limited.

Case-Control Studies↗

Prenatal ultrasound characterization of the suprarenal mass: distinction between neuroblastoma and subdiaphragmatic extralobar pulmonary sequestration.

With the increased routine use of prenatal ultrasonography, subdiaphragmatic masses in the fetus are identified more frequently. Suprarenal masses often are presumed to be neuroblastoma and are removed surgically postnatally. We sought to better understand the natural history of subdiaphragmatic extralobar pulmonary sequestration, and to determine if subdiaphragmatic extralobar pulmonary sequestration can be distinguished preoperatively from neuroblastoma. The literature was reviewed for cases of prenatally diagnosed suprarenal masses that proved ultimately to be either subdiaphragmatic extralobar pulmonary sequestration or neuroblastoma. The distinguishing features of the two lesions were identified and an algorithm was created on the basis of these distinctions. Prenatally diagnosed subdiaphragmatic extralobar pulmonary sequestration is no longer rare, with one case being reported for every 2.5 cases of neuroblastoma. On prenatal ultrasonography subdiaphragmatic extralobar pulmonary sequestration usually is echogenic, is left-sided, and can be identified in the second trimester. Neuroblastoma is most often cystic, right-sided, and identified in the third trimester. In summary, subdiaphragmatic extralobar pulmonary sequestration must be considered in the differential diagnosis of the suprarenal mass identified on prenatal ultrasonography. Using the algorithm which we propose, the correct diagnosis can be determined prenatally in 95% of patients.

Adolescent↗

Spiral CT: use in the evaluation of chest masses in the critically ill neonate.

The radiologic evaluation of neonatal chest masses may be carried out with a number of different imaging modalities, each with distinct advantages and disadvantages. While it is necessary clinically to rapidly and accurately diagnose these lesions, this may be difficult when the neonate is critically ill. We report the use of spiral (helical) CT (SCT) scanning with reconstructed images to diagnose chest masses in two critically ill neonates undergoing oscillating ventilation. We describe the technique used to image the masses and compare this technique with other available imaging modalities.

Aorta, Thoracic↗

Spontaneous colonic ischemia in a patient with Riley-Day syndrome.

Familial dysautonomia, or Riley-Day syndrome, is a hereditary disturbance in the autonomic and peripheral sensory nervous systems, first described by Riley, Day, and colleagues in 1949 [1, 2]. Previous reports of myocardial infarction and avascular necrosis in bone suggest that these patients are at risk for ischemia at certain organ sites [3, 4]. We report a case of spontaneous colonic ischemia and stricture which resulted in colocutaneous fistula formation and eventual colonic resection in a child with Riley-Day syndrome.

Child↗

Unilateral lymphangiectasis of the kidney: an unusual cause of renal enlargement in an infant.

We report on an infant with unilateral renal lymphangiectasia and the absence of small cysts in the renal parenchyma or renal hilum. We suggest that renal lymphangiectasia be part of the differential diagnosis in children who present with unilateral renal enlargement, especially when contrast enhanced computerized tomography shows preservation of a rim of renal cortex with decreased attenuation of the medulla and/or when ultrasound demonstrates increased echogenicity without displacement of the caliceal system.

Humans↗

Profound asphyxia in the premature infant: imaging findings.

PURPOSE: To investigate imaging findings in premature infants who had profound asphyxia. METHODS: CT (three patients), MR (three patients), and ultrasonography (four patients) studies of five patients who had profound asphyxia before the postconceptional age of 32 weeks were retrospectively reviewed. The patients ranged from 1 day to 4 months old at the time of the imaging studies. An autopsy report was available in one patient. The results were compared with reports in the literature of patients with similar injuries at similar ages. RESULTS: Abnormalities of the thalami and basal ganglia were present in all infants examined with CT or MR. CT showed low attenuation in the basal ganglia and high attenuation (blood or calcium) in the thalami; thalamic cavitation and low attenuation of the upper brain stem were present in one infant. MR showed T1 and T2 shortening in the thalami in all patients. Variable MR changes were noted in the basal ganglia, ranging from diminished size with normal signal intensity to T1 and T2 shortening with normal size and complete cavitation. T1 and T2 shortening were seen in the dorsal brain stem in one patient. Sonography showed transient or persistent hyperechogenicity in the thalami in three patients and cavitation of the thalami in one patient. Damage to the perirolandic cortex was not present in any patient. CONCLUSION: Profound asphyxia before 32 weeks gestational age shows consistent injury to the thalami, basal ganglia, and brain stem that can be detected by all three imaging modalities. The pattern of injury seems to differ from that of partial asphyxia in premature infants and of profound asphyxia in term infants.

Asphyxia Neonatorum↗

Variables that affect the expansion rate and outcome of small abdominal aortic aneurysms.

Seventy-three patients with small (less than 6 cm in diameter) abdominal aortic aneurysms (AAAs) were selected for nonoperative management and followed up with sequential ultrasound size measurements. Fifty-four men and 19 women, 51 to 89 years of age (mean 70 years), had an initial mean AAA size of 4.1 cm (anteroposterior) x 4.3 cm (lateral) diameter, with a calculated elliptic cross-sectional area of 14.3 cm2. After a mean of 37 months of follow-up, AAA area increased at a mean rate of 20% per year (3 cm2 yr; 0.4 to 0.5 cm/yr diameter). Expansion rate was not affected by initial aneurysm size. During follow-up, only 3 patients (4%) required urgent operation (1 died), 26 patients (36%) died of non-AAA causes, and 26 patients (36%) underwent elective AAA repair because of progressive size increase (1 died). Elective operations were performed at the rate of 10% per year, when mean AAA size had increased to 22 cm2 (5.1 cm in diameter). Multiple regression analysis of clinical parameters available at presentation indicated that subsequent elective AAA repair was predicted by younger age at diagnosis and larger initial aneurysm size. As anticipated, patients who underwent surgery had more rapid aneurysm expansion (5.3 cm2/yr) compared with patients who did not undergo surgery (1.6 cm2/yr; p less than 0.05). This difference was caused by more rapid expansion during later follow-up intervals among patients selected for operation and was not predicted by the change in aneurysm size observed during initial ultrasonographic follow-up. Final aneurysm size was predicted by initial size, duration of follow-up, and both systolic and diastolic pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗

Fetal choroid plexus cysts: prevalence, clinical significance, and sonographic appearance.

To determine the prevalence, sonographic appearance, and clinical significance of fetal choroid plexus cysts, we analyzed the sonograms and clinical records of 17 fetuses with cysts. Fetal and maternal age, sonographic indication, cyst size and multiplicity, and evolution on serial studies were recorded. Fetal outcome was available in 16 cases by genetic amniocentesis (n = 5) or neonatal clinical records (n = 11). The prevalence of fetal choroid plexus cysts was 0.8% (17/2084) during a 40-month period. All cysts were initially identified on sonograms performed between 14 and 21 weeks. Cysts ranged from 3 to 11 mm in size and were bilateral in four (36%) of 11 cases in which both lateral ventricles were visualized. In nine of 10 cases with serial sonograms 2-21 weeks after the initial study, the cysts were no longer present. One fetus had a small cyst persisting at term. All five cases with genetic amniocentesis had normal chromosomes. The only phenotypic abnormality in the 11 cases with clinical follow-up was a small hemangioma of the chest wall. We conclude that most fetuses with isolated choroid plexus cysts have a normal outcome and that serial sonography for cyst evaluation is not useful in determining fetal prognosis.

Brain Diseases↗

Prenatal diagnosis of a new syndrome: holoprosencephaly with hypokinesia.

Markedly decreased fetal activity (akinesia/hypokinesia) is usually readily apparent to experienced mothers, and frequently this concern leads to attempts at prenatal diagnosis. We report prenatal diagnosis of two fetuses with congenital contractures, markedly decreased fetal movement, and microcephaly due to severe holoprosencephaly. Such familial recurrence to phenotypically normal parents suggests a newly recognized autosomal recessive or X-linked syndrome that is readily detectable by prenatal ultrasonography.

Abnormalities, Multiple↗

Mammographic changes following reduction mammaplasty.

Mammographic findings after reduction mammaplasty may be similar to those seen with carcinoma. A knowledge of the expected mammographic alterations would be helpful in differentiating postoperative changes from those seen with carcinoma of the breast. Accordingly, the clinical records and mammograms of patients who underwent reduction mammaplasty at the Dartmouth-Hitchcock Medical Center between March of 1977 and July of 1985 were analyzed. Forty-two patients had at least one mammographic examination following reduction mammaplasty. Periareolar soft-tissue changes and inferior pole alterations were present in almost all examinations of patients during the first 6 months after operation, but they decreased during the next few years. Asymmetrical densities were present in approximately half the patients throughout the follow-up period but decreased in degree. Parenchymal calcifications occurred later; few x-rays showed these calcifications during the first year, but 50 percent were apparent after 2 years. Evidence of fat necrosis occurred in approximately 10 percent. Four patients had biopsies for suspicious densities. Chronic inflammation and inclusion cyst were reported. We believe that changes after reduction mammaplasty are predictable and can usually be differentiated from those associated with cancer.

Adipose Tissue↗

External ventricular drainage for initial treatment of neonatal posthemorrhagic hydrocephalus: surgical and neurodevelopmental outcome.

Thirty-seven infants were treated for posthemorrhagic hydrocephalus (PHH) with external ventricular drainage (EVD) in 1977-1985. The mean age at EVD placement was 13 days; the mean duration of drainage was 21 days, and an average of 1.8 drains was used per patient. Complications were apnea (10%), hemorrhage (8%) and ventriculitis (6%). Ten infants died from pulmonary disease unrelated to the surgery. Thirty-two percent of the survivors did not require a permanent shunt. Neurodevelopmental outcome was evaluated at a mean age of 38 months. Eighteen of the twenty-seven survivors (67%) had normal cognitive function, 3 had borderline and 6 (22%) had moderate to profound mental retardation. Nine of the children (33%) had a normal neuromuscular exam. One child had mild, 11 had moderate and 6 had severe cerebral palsy. Four children had serious visual impairment. The worst outcomes were in the children with parenchymal or large intraventricular hemorrhages.

Cerebral Hemorrhage↗