PubMed Health⌕ Search

Biomedical subjects

P S Babyn

Publications and source records attributed to P S Babyn.

At least 37 records · Page 2Linked to original sources
PubMed1995

Imaging of immature articular cartilage using ultrasound backscatter microscopy at 50 MHz.

A high frequency sonographic technique-ultrasound backscatter microscopy-was used to visualize the subsurface structure of immature porcine articular cartilage from the knee joint. In 20-week-old pigs, all parts that were scanned, except the weight-bearing regions of the femoral condyles, demonstrated heterogeneous ultrasound backscatter characteristics within the articular cartilage. A trilaminar pattern consisting of hypoechoic, hyperechoic, and anechoic layers ranging from superficial to deep generally was observed, except in the weight-bearing regions of the femoral condyles, where a homogeneous anechoic pattern was seen. In the younger pigs (6 and 10 weeks old), the trilaminar backscatter pattern was not observed. Small, highly echogenic structures that correlated with vascular channels in histologic assessment were observed frequently in the cartilage of younger pigs, but they were seldom present in the cartilage of 20-week-old pigs. Structural details, such as disruption of the subchondral bone and presence of a thickened fibrous layer on the articular surface at the chondrosynovial junction, also were detected with the ultrasound backscatter microscope. We concluded that high frequency ultrasound can be used to visualize the subsurface structure of immature articular cartilage and some of its developmental changes. Further research is required to explain the mechanism underlying the observed backscatter characteristics of immature articular cartilage and to study its potential for the imaging of pathologic changes.

Animals↗
PubMed1995

Intussusception: ability of fluoroscopic images obtained during air enemas to depict lead points and other abnormalities.

PURPOSE: To evaluate the ability of fluoroscopic images obtained during air enemas to depict or exclude lead points of intussusceptions and other abnormalities that require surgical treatment in the absence of intussusception. MATERIALS AND METHODS: The clinical, radiologic, surgical, and pathologic findings were reviewed in 14 patients with lead points or other lesions. RESULTS: Fluoroscopic images failed to depict a lead point in 10 patients. The air enema easily reduced intussusceptions with benign lead points in seven patients. Fluoroscopic images depicted pathologic lead points in two patients and were normal in two patients with intussusception. Fluoroscopic images failed to depict an abnormality that required surgery in the absence of intussusception in two patients. CONCLUSION: Successful reduction of an intussusception does not always rule out a lead point. Other imaging studies, the patient's condition, and laparotomy may also be necessary to diagnose and treat lead points and other lesions.

Adolescent↗
PubMed1995

Diagnosis from single-digit radiography.

This pictorial assay illustrates the value of plain radiographs of the digit in diagnosing disease in children. Although the hand is regarded as a mirror of disease, the finger often points to the correct diagnosis. The authors present a series of cases for which a coned-down view of a single digit is given. In some cases the findings indicate a specific diagnosis, whereas in others only a differential diagnosis is possible. The radiographic findings and a brief differential diagnosis, as well as the definitive diagnosis, are presented for each case.

Adolescent↗
PubMed1995

Osteoarthritis in rhesus macaque knee joint: quantitative magnetic resonance imaging tissue characterization of articular cartilage.

OBJECTIVE: To assess cartilage matrix quality variation by anatomical location and extent of osteoarthritis (OA) using quantitative magnetic resonance imaging (MRI) and to compare the anatomic MR morphologic features with corresponding histological findings. METHODS: We studied 18 fully encapsulated right knee joints from a population of rhesus monkeys with a high incidence of degenerative arthritis resembling human OA. Relaxation times (T1 and T2) spin density, and cartilage thickness were determined along 8 contiguous anteroposterior segments of articular cartilage. Histological slides, prepared in the same plane as the MR image, were assessed for OA severity. Using a modification of Mankin's OA classification, each quadrant was grouped into normal (0), mild (1), moderate (2), or severe OA (3). Histopathological scores served as the standard and corresponding MR quadrants were classified accordingly. RESULTS: Cumulative results revealed a significant decrease in T1 relaxation time (p = 0.04) and an increase in T2 relaxation time (p = 0.03) in the mild and severe OA groups, respectively. Statistically significant changes in spin density and cartilage thickness measurements were not observed. MR signal intensity abnormalities in selected regions of interest were demarcated and studied histologically. Regions with histological proliferating chondrocytes or fibrillated cartilage showed bright signal intensity on MR images (TR = 3000 ms; TE = 10 ms) and corresponded with elevated T1 and T2 values. Histological regions of collagen condensation showed low signal intensity on MR images (TR = 3000 ms; TE = 10 ms) and corresponded with decreased T1 and T2 relaxation times. CONCLUSION: Topological quantitative MRI relaxation time assessment demonstrates increasing cartilage matrix quality variation with OA progression.

Animals↗
PubMed1994

Spontaneous non-traumatic anterior compartment syndrome with peroneal neuropathy and favorable outcome.

We report a girl who spontaneously developed an anterior compartment syndrome with an associated deep peroneal neuropathy. Initial nerve conduction studies (NCS) recorded from the extensor digitorum brevis muscle demonstrated prolongation of the distal latency to 7.8 msec (normal contralateral side, 3.6 msec), and reduction in amplitude of the compound muscle action potential to 0.1 mV (normal contralateral side, 9.9 mV). Electromyography of the tibialis anterior muscle showed an absence of motor unit potentials. Serum creatine kinase was markedly elevated to 12,769 IU. Computed tomography (CT) showed evidence of necrotic muscle. One month later, the foot drop, repeat NCS, and CT demonstrated a significant improvement with conservative management.

Anterior Compartment Syndrome↗
PubMed1993

Comparison of sedation regimens for pediatric outpatient CT.

The purpose of this study was to compare the concurrent use of chloral hydrate (CH), intramuscular Nembutal (IMN) and intravenous Nembutal (IVN) for sedation. Data was collected on all pediatric outpatients requiring sedation for CT over a 2.5-year period. During this period, 2178 outpatients required sedation of whom, 1324 (60.8%) received IMN, 710 (32.6%) IVN and 110 (5%) CH. The overall success rate was 97% and was similar in all three groups. IVN however, produced better-quality sedation than IMN or CH. The IVN group received a significantly lower dose of Nembutal than the IMN group (p = 0.001). Patients receiving IVN had a significantly lower induction time (p = 0.0001) and total examination time (p = 0.001) than IMN or CH. There was an increased occurrence of desaturation in patients sedated with IVN, especially in those with airway obstruction. IVN sedation permits faster, more efficient and better-quality sedation for outpatient CT scanning than IMN or CH in patients requiring intravenous contrast but may not be appropriate for departments that perform relatively few sedations or lack proper resuscitation facilities.

Ambulatory Care↗
PubMed1993

Spinal deformities in deferoxamine-treated homozygous beta-thalassemia major patients.

A new constellation of spinal changes are observed in homozygous beta-thalassemia major (HBT) patients receiving deferoxamine (DF), an iron-chelating drug used in combination with transfusion therapy in certain anemic syndromes. In a retrospective study of 22 HBT patients who were receiving DF therapy, morphological deformities (decreased spinal height, increased thoracic kyphosis, vertebral flattening and elongation anteriorly, and disk calcification) were found in 16 of 22 patients. These changes are believed to be caused by interference with spinal growth-plate development. Investigation of DF-dose correlation supports the conclusion that the spinal changes were DF-induced. Spinal changes observed in DF-treated patients differ both morphologically and pathogenetically from earlier reports of vertebral deformities occurring as a sequel to compensatory marrow hyperplasia in poorly transfused patients.

Adolescent↗
PubMed1993

Metastatic choriocarcinoma in an infant: imaging appearance.

Metastatic choriocarcinoma is unusual in infancy and considered to be due to metastases from the placenta. Only fifteen cases have been previously reported. We present an unusual case of hepatic, pulmonary, and axillary lymph node metastases from choriocarcinoma in a 3-month-old female. Several of the lesions had large vascular channels identified by computed tomography and sonography with color and duplex Doppler.

Choriocarcinoma↗
PubMed1993

CT of blunt chest trauma in children.

While trauma is still the leading cause of death in the pediatric age range, it is surprising how little the CT appearances of pediatric chest injury have been investigated in the literature. We have reviewed the CT findings of blunt chest trauma in 44 children for whom chest CT examinations were requested to investigate the extent of intrathoracic injury. We noted a propensity for pulmonary contusions to be located posteriorly or posteromedially, and for them to be anatomically nonsegmental and crescentic in shape. This is possibly attributable to the relatively compliant anterior chest wall in children. The CT appearances of other major thoracic injuries are described, including pulmonary lacerations, pneumothoraces, malpositioned chest tubes, mediastinal hematomas, aortic injury, tracheobronchial injury, hemopericardium, and spinal injuries with paraspinal fluid collections. Children demonstrating findings incidental to the actual injury yet important to the subsequent therapy are also presented. We conclude that, in the event of clinically significant blunt chest trauma, the single supine chest examination in the trauma room is insufficient to adequately identify the extent of intrathoracic injury. With the exception of concern for aortic injury for which aortography is indicated, a dynamically enhanced CT scan of the thorax should be performed as clinically significant findings may result in altered therapy.

Adolescent↗
PubMed1993

Extremity osteosarcoma in childhood: prognostic value of radiologic imaging.

PURPOSE: To evaluate previously described radiologic prognostic factors in extremity osteosarcoma. MATERIALS AND METHODS: In 47 pediatric patients, available images were evaluated for seven prognostic factors at diagnosis and seven additional factors after preoperative chemotherapy. These factors were correlated with histopathologic response and clinical outcome. The association of histopathologic response and outcome was also evaluated. RESULTS: Metastases at presentation and a > 20-cm-diameter soft-tissue mass were predictive of a poor outcome but occurred in few patients. Factors most predictive of < 90% tumor necrosis after chemotherapy included an increase or no change in soft-tissue mass size and increased bone destruction. Although a significant relationship (P < .05) was found between histopathologic response and outcome, no factors predictive of histopathologic response were also predictive of outcome. The accuracy of pathologic response in predicting outcome was 66%. CONCLUSION: Radiologic studies are of only limited use in predicting which patients with extremity osteosarcoma will have a poor response to chemotherapy or a poor outcome, and are not useful in predicting a good response or outcome.

Adolescent↗
PubMed1993

Value of CT in determining the resectability of hepatoblastoma before and after chemotherapy.

OBJECTIVE: The purpose of this study was to assess the accuracy of CT for determining surgical resectability of hepatoblastoma before and after chemotherapy. MATERIALS AND METHODS: Preoperative and postoperative CT scans of 15 children with surgically confirmed hepatoblastoma were retrospectively reviewed and correlated with surgical findings and pathologic analysis. RESULTS: Before chemotherapy, 12 of the 15 children had unresectable tumors because of bilobar involvement, metastatic disease, or vascular extension. After chemotherapy, tumor volumes decreased by 20-98%, with increased areas of low attenuation and calcification. Periportal areas of low attenuation (four of nine), abdominal adenopathy (four of four), and lung nodules (four of six) disappeared after chemotherapy. On the basis of CT and clinical findings, all tumors were thought to be resectable. Surgical correlation showed that the extent of hepatic tumor had been overestimated on immediate preoperative CT scans in three children (tumor was staged as bilobar, but only single-lobe resection was required). Correlation between areas of low attenuation in the tumor and necrosis in pathologic specimens was poor. Tumor invasion of periportal lymphatics was seen in one of five children with periportal areas of low attenuation. Postoperatively, five of 13 children had CT abnormalities, three at the resection margins with calcification, low attenuation, or both. Hepatic or abdominal disease has not recurred, and 12 of the 14 children who survived surgery are well. One child who had abnormal findings on preoperative chest CT died of pulmonary metastases. Another in whom chemotherapy was limited because of toxic effects died after tumor recurred in the liver. CONCLUSION: Pretreatment CT scans cannot be used to predict ultimate resectability of hepatic tumors; nor are preoperative scans always accurate for judging exact lobar involvement. Absence of disease as shown on CT scans correlated with absence both at surgery and at follow-up. Postoperative hepatic changes are common and do not necessarily reflect recurrent or residual tumor.

Carcinoma, Hepatocellular↗
PubMed1993

Aggressive fibromatosis simulating congenital lung malformation.

Aggressive fibromatosis is a locally invasive, non-metastasizing tumour of fibrous origin and variable radiologic appearance. The authors describe a child with intrathoracic aggressive fibromatosis that mimicked congenital malformation of the lung.

Cystic Adenomatoid Malformation of Lung, Congenita↗
PubMed1992

New concepts in imaging of the gastrointestinal tract in children.

This article highlights some of the significant recent advances in imaging of the pediatric gastrointestinal tract that have occurred over the last decade. The current roles of the newer imaging modalities, including ultrasound, computed tomography, and magnetic resonance imaging, are discussed and illustrated. Particular emphasis is given to antenatal evaluation, suspected gastric outlet obstruction, inflammation, and other causes of the acute abdomen. Enhancements in fluoroscopic techniques are outlined, including the use of the newer contrast agents as well as air reduction of intussusception. Continued good communication between the pediatric radiologist and pediatric surgeon is vital to improve the care to children with disorders of the gastrointestinal tract.

Abdomen, Acute↗
PubMed1992

The computed tomographic appearance of subcutaneous nodules occurring in metastatic neuroblastoma.

The authors report a case of subcutaneous nodules in a 2-month-old girl with metastatic neuroblastoma; the appearance of the nodules in computed tomography scans is described. Such nodules are sometimes overlooked by clinicians and radiologists, even though they almost always occur in disseminated disease. In patients with neuroblastoma and other neoplasms subcutaneous nodules may be an easily accessible source of samples for histopathologic examination.

Adrenal Gland Neoplasms↗
PubMed1991

Preoperative chemotherapy in hepatoblastoma.

Since January 1986, 15 children with hepatoblastoma received three to six cycles of chemotherapy with cisplatin (20 mg/m2/day x 5 days) and doxorubicin hydrochloride (25 mg2/m2/day x 3 days) every 3 weeks before surgery. The extent of the tumor was defined by computerized tomography scan of abdomen and chest and diagnosis confirmed by percutaneous liver biopsy before therapy was started. Tumors in 10 children were considered unresectable at diagnosis because of pulmonary metastases, extensive bilobar involvement, or venous involvement. Volume of tumor reduction ranged from 35% to 95% and was independent of tumor histologic findings. After a minimum of three chemotherapy cycles, excision was undertaken when tumor volume decreased to a size at which hepatic resection was feasible and safe. Chemotherapy complications that were not serious did not delay surgery or result in tumor growth during treatment. Complete surgical excision was possible in 13 children, including 10 who had had unresectable tumors and five with pulmonary metastases. Only three resections of more than one liver lobe were required, and partial lobectomy was possible in four children. One operative death and three postoperative complications, one severe, occurred. Cyclic chemotherapy was restarted 4 to 6 weeks after surgery until a total of six courses were given. Twelve children (eight whose tumors were originally unresectable) completed treatment 3 to 56 (median, 21) months ago and have no evidence of disease. Two other children currently undergoing therapy may have residual disease. The results to date far surpass historic survival rates, which ranged about 25%.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1988

Sonographic evaluation of spinal cord birth trauma with pathologic correlation.

Birth trauma to the spinal cord is a serious potential complication of delivery. Determining the presence, severity, and extent of injury poses a difficult problem because of the often confusing clinical setting. Myelography has been recommended for assessing spinal cord birth trauma but is invasive and may not be helpful. The role of sonography in evaluating spinal cord birth trauma has not been previously described. We assessed the value of sonography in four patients, three of whom also had CT metrizamide myelography. Autopsy correlation was available in three patients. Sonography was able to easily demonstrate the cord configuration, allowing for multiple assessments over time. Internal cord echogenicity was helpful in a case of hematomyelia and in demonstrating the changes of myelomalacia. Sonography is useful in evaluating neonates with severe spinal cord injury; it obviates the need for myelography and also may allow less severely injured patients to be assessed more frequently.

Birth Injuries↗