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Biomedical subjects

T L Slovis

Publications and source records attributed to T L Slovis.

At least 55 records · Page 3Linked to original sources

Hyperechoic kidneys in the newborn and young infant.

Increased echogenicity of the kidney in the newborn has many causes, some of which reflect serious renal disease. The major abnormal imaging pattern is the large, diffusely hyperechoic kidney with abnormal architecture. Its differential diagnosis includes recessive and dominant polycystic kidney disease (PKD), glomerulocystic kidney disease, and diffuse cystic dysplasia. The family history and ultrasonic screening of the parents and siblings are essential in the evaluation. The identification of associated nonrenal abnormalities is important to the recognition of syndromal cystic disease. Glomerulocystic kidney disease, which comprises sporadic and syndromal forms, appears similar to dominant PKD. While renal biopsy almost always differentiates recessive from dominant PKD, renal biopsy cannot differentiate among the forms of glomerulocystic kidney disease, except in the case of tuberous sclerosis, which has unique histopathological characteristics. Other causes of the enlarged hyperechoic kidneys with abnormal architecture include renal vein thrombosis and congenital nephrotic syndrome. A second pattern is the hyperechoic small kidney with abnormal architecture. Many of these kidneys are dysplastic and associated with urinary tract obstruction. The combination of hyperechoic parenchyma and pyelocaliceal dilatation suggests obstructive cystic dysplasia. Cortical and medullary necrosis in the newborn also causes hyperechogenicity in small kidneys. A third pattern contains those kidneys with medullary hyperechogenicity, the most common cause of which in the newborn is nephrocalcinosis associated with furosemide therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Diagnosis, Differential↗

Pediatric sedation: short-term effects.

A prospective investigation on the short-term effects of various sedation regimens on 549 nonhospitalized magnetic resonance (MR) patients was performed. The drugs evaluated were chloral hydrate, pentobarbital, midazolam, and diazepam (fentanyl was used for enhancement after any of these drugs). The overall safety and efficacy were quite good with all the regimens. Overall, 84% of children slept less than 8 h after the examination, 90% were drowsy and/or unsteady for less than 8 h after they awoke, and 97% resumed their usual activities by 24 h. Significant hyperactivity was seen only with pentobarbital and occurred in 8.4% of children over 8 years of age. The multiple-dose regimen of pentobarbital and fentanyl had a significant short-term effect on the children less than 8 years of age, with 35% sleeping longer than 8 h after the MR. Ten children who had needed the multiple-dose pentobarbital regimen or who had failed prior pentobarbital sedation presented for repeat sedation. Midazolam was effective in 9 of these 10 children.

Child, Preschool↗

Imaging of mediastinal masses in children.

Conventional radiographs show the mediastinum to be the most frequent location of thoracic masses in children. The compartmental approach to evaluation of pediatric mediastinal masses is advised. Compartmental localization and lesion internal characteristics are best determined by cross-sectional imaging techniques. These techniques as well as the causes and significance of the common pediatric mediastinal masses are discussed. Imaging of the thymus is emphasized because normal thymic tissue can mimic pathologic conditions and the thymus is a common thoracic location for neoplasms in children.

Child↗

Recurrent pneumatosis intestinalis in young infants.

In 67 infants with necrotizing enterocolitis (NEC) at Children's Hospital of Michigan from 1987-1990, three had recurrent pneumatosis intestinalis (PI) after the neonatal period and after hospital discharge. All three infants were premature (26-34 weeks), and one had an additional risk factor of gastroschisis. All three had their initial episode of NEC within the first month of life. Two had bowel resections, and one was treated medically. 15 h to seven months after discharge from the hospital, all three infants developed recurrent PI at ages ranging from 2.5 to 9 months. Two of the infants had free intraperitoneal air. Though all three infants had PI, only one had true recurrent NEC with ischemic bowel and died. This baby was the only one with rotazyme positive stools. The second infant, who had surgery for gastroschisis, had incomplete obstruction secondary to adhesions resulting in PI. Since surgery this infant has thrived. The third infant had extensive PI of the colon with free air. At surgery there was no evidence of bowel perforation. The free air was attributed to rupture of one of the many colonic cysts of PI. Subsequently, the child has done well. Recurrent PI in infants who have had NEC is unusual and the causes are varied. Because more neonates are surviving NEC, the pediatric radiologist needs to be aware of this delayed complication.

Age Factors↗

Aberrant thymus--MR assessment.

Aberrant thymic tissue, particularly when it is located posteriorly, can present a diagnostic dilemma. Once a mediastinal "lesion" is defined on the plain film, MR is the most efficient and best diagnostic test for defining the nature of the mass and showing its relationship to other mediastinal structures. Two cases of aberrant thymic tissue, one on the right side and one on the left, are presented to elucidate the unique role of MRI.

Choristoma↗

Imaging of Wilms' tumor: what is important!

The imaging of Wilms' tumor needs to be quite focused so that the oncologist and surgeon can most precisely stage the patient before operation. The imager needs to be exact about the extent of the primary tumor and define any invasion into the adjacent soft tissues. The ability to detect nodal disease is quite difficult but clearly influences the preoperative approach and staging. Children with large tumors extending across the midline in whom primary resection may lead to tumor spillage are prime candidates for preoperative chemotherapy, and the imager has significant input in making this decision. The imager must define metastases in the lungs and the liver and evaluate the risk of bilateral tumor (particularly metachronous) by searching the index kidney for multifocal lesions or nephroblastomatosis in either kidney.

Child↗

Congenital subglottic hemangioma: frequency of symmetric subglottic narrowing on frontal radiographs of the neck.

OBJECTIVE: This study was undertaken to determine how often symmetric subglottic airway narrowing is present in cases of infantile subglottic stenosis and to determine if the radiographic finding has any association with the anatomic location of the hemangioma. MATERIALS AND METHODS: All cases (n = 12) of endoscopically proved subglottic hemangioma from 1976 to 1991 were collected from the records at Children's Hospital of Michigan. In 10 cases, high-kilovoltage magnification studies or frontal radiographs of the neck were available for review by two observers who classified the subglottic narrowing as either symmetric or asymmetric. The radiographic findings in these 10 cases were then compared with the location and extent of the lesion as described endoscopically. RESULTS: In 50% of cases (n = 5), narrowing of the subglottic airway was symmetric. In four of these the hemangioma was either situated on the posterior wall or was circumferential, and in the remaining one an associated marked fibrotic reaction to a lateral wall lesion was present. All other lesions were on the lateral wall, and asymmetric subglottic airway narrowing was consistently shown on radiographs. CONCLUSION: Our results show that subglottic hemangioma often manifests as a symmetric subglottic airway narrowing and that the anatomic location of the hemangioma appears to be associated with the appearance on radiographs.

Glottis↗

The clinical usefulness of teleradiology of neonates: expanded services without expanded staff.

Teleradiology was utilized to link an offsite, high-risk nursery to the Department of Pediatric Radiology of Children's Hospital of Michigan. Interpretations via teleradiology were made in 4200 examinations and taken as the final reading. There was no expansion of either professional or technical personnel at either hospital to accomplish these ends. During the initial 3 months of the study, 40% of the teleradiographic images were double-read to evaluate the accuracy of the technique. During the subsequent 9 months, 17% of the cases were double-read, for an overall double-reading of 23%. There was a 98% agreement between the interpretations made using teleradiology and those made using hard copy. In no instances of the 2% (20 cases) in which there was disagreement between readings did the difference have clinical significance. Our results indicate that teleradiology linkage for interpreting neonatal examinations serves as a valuable tool for expansion of subspecialty expertise, allows more expedient recognition of abnormalities in the neonate, and facilitates faster transport to the appropriate tertiary care center.

Computer Communication Networks↗

Comparison of indium-111 scintigraphy and colonoscopy with histologic study in children for evaluation of colonic chronic inflammatory bowel disease.

Indium-111 leukocyte scanning and colonoscopy were performed in 19 children and adolescents with chronic inflammatory bowel disease to study the correlation of evaluation between these two diagnostic modalities in comparison to histologic study for colonic disease. Seven patients had ulcerative colitis, 10 had Crohn's disease, and two patients had no specific diagnosis after evaluation. The sensitivity of indium-111 scan was 18%, specificity was 62.5%, and accuracy for diagnosing colonic disease was only 37%. In comparison, sensitivity and specificity for colonoscopy were 100 and 57%, respectively. Furthermore, accuracy with colonoscopy was 84%. Our data suggest that the usefulness of scans is limited to patients in whom standard diagnostic procedures are contraindicated. In addition, it is essential to confirm the visual diagnostic impression on colonoscopy with histologic study.

Adolescent↗

Transcranial sonography through the burr hole for detection of ventriculomegaly. A preliminary report.

Detection of ventriculomegaly in a child with a ventricular shunt is important in the diagnosis of shunt malfunction. The feasibility of visualizing the ventricles through a 2-cm burr hole, with the use of a small-footprint 7-MHz transducer, was evaluated in five infants. Each burr hole remained patent during the study (2-6 months), and in all infants correlation between views through the anterior fontanelle and the burr hole were in agreement. When ventriculomegaly can be detected by this technique, the need for CT evaluation may be obviated. Further study is necessary to evaluate extended burr holes in older children compared to their CT examinations.

Arachnoid Cysts↗

Accuracy of ultrasonic bladder volume measurement in children.

The accuracy of ultrasonography in assessing the bladder volume in 13 children with normal bladder contours was determined using the formula D x H x W (depth x height x width) with a mean error of 15.7%. This formula tends to overestimate the bladder volume in these patients. Multiplication by a correction factor of 0.9 yields a mean error of 11.5%. The accuracy of this evaluation is not dependent upon the bladder volume as the mean error was the same in those children whose bladder volume was either less than or greater than 150 cc. In addition, the accuracy of ultrasonography in assessing bladder volume was evaluated in 7 patients with an abnormal bladder contour (trabeculation, diverticula, etc.); mean error was 14.7%. In these 7 patients there was no predictable under or overestimation of bladder volume. In the children with abnormal bladder contours on ultrasound, the correction factor of 0.9 should not be used, as it does not add to the accuracy of the procedure in any individual patient. This technique is still valuable, however, in children with an abnormal bladder for it allows estimation of the extent of emptying without invasive catheterization.

Adolescent↗

Congenital neuroblastoma: evaluation with multimodality imaging.

The authors retrospectively evaluated 12 patients with congenital (neonatal) neuroblastoma to assess the utility of newer imaging modalities. Findings at prenatal ultrasound (US), performed in four patients, were nonspecific (hydramnios and hydrops fetalis) in two and consistent with a suprarenal mass (one solid, one cystic) in the other two. Postnatal US helped accurately detect adrenal tumors (solid or complex, with one exception) but was less accurate in the diagnosis of metastatic disease to the liver. Computed tomography accurately depicted all primary tumors and liver metastases. Magnetic resonance (MR) imaging helped establish the correct diagnosis in three patients. This study again confirmed the benign course of neonatal neuroblastoma, with 50% of the patients classified with stage IV-S disease and two deaths occurring in the series, both due to complications. Therefore, aggressive diagnostic imaging is less desirable, and US is therefore very useful, despite its limitations. The prenatal detection and solid appearance of a suprarenal mass makes the diagnosis of neuroblastoma very likely, as does the presence of liver lesions. In the absence of these characteristic findings, US should be repeated to exclude adrenal hemorrhage. MR imaging seems to be a good alternative in some instances.

Adrenal Gland Neoplasms↗

Sonographic and Doppler features of infantile hepatic hemangiomas with pathologic correlation.

The sonograms of five patients with a diagnosis of infantile hepatic hemangioma were retrospectively reviewed to analyze their sonographic and Doppler characteristics. Three patients had single lesions, whereas two had multifocal involvement. All lesions except one were hypoechoic, well-circumscribed, and solid; the exception was hyperechoic. Findings of high flow, ie, large draining veins, an abrupt change in aortic caliber, and the presence of Doppler signal throughout the lesion were seen in three of five patients. The sonographic findings correlate well with the pathologic findings of multiple vascular channels separated by fibrous septa. The major differential diagnosis of infantile hepatic hemangioma includes hepatoblastoma and metastatic neuroblastoma. Although some of their sonographic features may simulate a hemangioma, large draining veins and changes in aortic caliber are not reportedly seen. Doppler flow was not seen in either of these malignant neoplasms in our study and, to date, has only been reported peripheral to three cases of hepatoblastoma and not at all in metastatic neuroblastoma. We propose an algorithmic approach dependent upon the sonographic-Doppler appearance.

Hemangioma, Cavernous↗

Evaluation of the vomiting infant.

This 12-month prospective study was undertaken to evaluate the cost, risk, and benefit of ultrasound followed by upper gastrointestinal series for the evaluation of the infant who vomits. Results suggest minimal morbidity from the upper gastrointestinal series, only a 33% reduction in the number of upper gastrointestinal series performed, and a 95% increase in cost if this imaging sequence is used. We conclude that the use of ultrasound for the initial evaluation of vomiting in infants substantially increases the cost with no meaningful decrease in morbidity and mortality.

Digestive System↗