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Biomedical subjects

B K Han

Publications and source records attributed to B K Han.

At least 73 records · Page 4Linked to original sources
PubMed1984

Sonography of brain tumors in infants.

Cranial sonograms of six children with brain tumors (one newborn, four infants, and one 4-year-old child) are presented. In four, sonography showed a large tumor mass and displacement of adjacent structures. In two, the tumors were demonstrated as areas of abnormal brain parenchymal echogenicity without obvious mass effect. Two of the tumors were diffusely echogenic, one was primarily cystic, and three were of mixed echogenicity. Areas of cystic degeneration and calcification within the tumors were well demonstrated. Correlation was made with cranial computed tomography (CT) in all patients; in each case sonography accurately demonstrated the location and extent of the tumor. Since sonography is used as a screening procedure in infants with a large head or an abnormal neurologic examination, sonography may be the first examination to demonstrate the tumor mass. However, since the sonographic features are not specific for neoplasms, further clarification of the process by CT should be recommended.

Astrocytoma↗
PubMed1983

Secondary hyperparathyroidism and bone disease in infants receiving long-term furosemide therapy.

Four preterm infants receiving long-term furosemide therapy were examined for hypercalciuria, hyperparathyroidism, renal calcification, and bone demineralization. All four infants had increased urinary calcium excretion. Three infants had high serum concentrations of parathyroid hormone, and in these three infants, bone mineral content was below the mean of "osteopenic" preterm infants of comparable gestational and postnatal age. In two of these infants, there was ultrasound evidence of renal calcification. In one infant, autopsy disclosed bone changes of hyperparathyroidism, gallstones, and calcification in the heart and kidney.

Bone Diseases↗
PubMed1983

Optimal timing for diagnostic cranial ultrasound in low-birth-weight infants: detection of intracranial hemorrhage and ventricular dilation.

Intracranial hemorrhage and posthemorrhagic ventricular dilation are common problems in small preterm infants. To determine the optimal timing for ultrasound diagnosis of these abnormalities, we studied 64 preterm infants (less than 1,500 gm) by sequential cranial ultrasonography from birth until one year of age or until death. The optimal timing for ultrasound diagnosis of intracranial hemorrhage is days 4 to 7 with follow-up at day 14. The most efficient time for ultrasound examination to diagnose ventricular dilation was day 14 with follow-up at 3 months. Intracranial hemorrhage was diagnosed by ultrasound in 35 of the 64 patients (55%). In 18 of the 64 infants (28%) significant ventricular dilation was diagnosed by ultrasound during the first three months.

Cerebral Hemorrhage↗
PubMed1981

The accuracy of high resolution, real-time ultrasonography of the head in infancy.

A technique for imaging the infant head is described, which uses commercially available, high resolution, real-time ultrasonography. Serial scans are obtained in axial, coronal, and sagittal planes. Normal anatomic structures such as ventricles, cerebral peduncles, pons, cerebellum, sulci, gyri, choroid plexus, falx cerebri, and tentorium cerebelli can be demonstrated. From May through December 1979, over 200 examinations were performed on 136 patients younger than two years; 42 cases were normal and 94 abnormal, with hydrocephalus of various etiologies the most common abnormality. Developmental anomalies such as Dandy-Walker cyst, intraventricular and intracerebral hemorrhage, subdural hematomas, arachnoid cysts, and tumors were demonstrated. Correlation by clinical follow-up, computed tomography, or pathologic examination was available on 94 patients; correlation was excellent. The resolution approaches that possible with an articulated-arm, digital B-scanner.

Brain↗
PubMed1981

Caffey award: cranial sonographic findings in meningomyelocele.

Children with meningomyeloceles have problems involving several organ systems and often require repeated radiologic examinations. They have multiple cranial defects, particularly the Arnold-Chiari II malformation and associated hydrocephalus. Cranial sonographic findings in 29 patients included hydrocephalus with pointing of the frontal horns, asymmetry of the lateral ventricles, and relative enlargement of the occipital horns compared with the frontal horns. Partial absence of the septum pellucidum, abnormalities of the third ventricle including a prominent massa intermedia, prominent anterior commissure, and prominent suprapineal recess were also seen. A V-shaped tentorium cerebelli was demonstrated on axial scan as well as low position of the tent on coronal scan. The posterior fossa pseudomass was demonstrated. A prominent interhemispheric fissure was also seen in some patients. Sonography is an excellent method for following ventricular size and shunt function since repeated examinations can readily be performed.

Abnormalities, Multiple↗
PubMed1981

Choledochal cyst with bile duct dilatation: sonography and 99mTc IDA cholescintigraphy.

Three cases of choledochal cyst associated with intrahepatic biliary dilatation are presented. Findings on sonography included a large cystic mass in the porta hepatis separate from the gallbladder; a dilated common hepatic or common bile duct entering directly into the cyst; the smaller cystic masses of dilated central intrahepatic ducts. The dilatation of the central intrahepatic bile ducts was moderate in two patients and massive in one patient. All three patients underwent operation with intraoperative cholangiography. Two patients had 99mTc IDA cholescintigraphy which confirmed the diagnosis of choledochal cyst by demonstrating filling of the cyst with stasis and delayed intestinal activity. The accurate preoperative diagnosis of choledochal cyst, made by sonography combined with 99mTc IDA cholescintigraphy, obviated invasive studies.

Bile Duct Diseases↗
PubMed1980

Pulmonary vascular sling with tracheobronchial stenosis and hypoplasia of the right pulmonary artery.

We present a case of pulmonary sling associated with tracheobronchial stenosis, and with hypoplasia of the right lung and right pulmonary artery. Radiologic studies showed evidence of pulmonary sling and hypoplasia of the right lung; associated hypoplasia of the right pulmonary artery was also present, but not recognized initially. Narrowing of the distal trachea and right main bronchus was present, not due to compression by the anomalous left pulmonary artery, but to congenital stenosis of the trachea and right main bronchus associated with complete cartilaginous tracheobronchial rings.

Bronchial Diseases↗
PubMed1980

B-mode gray scale ultrasound of the head in the newborn and young infant.

A technique using commercially available B-mode gray scale ultrasonography for imaging the head in the newborn and young infant is described. Serial scans were performed at several angles from the canthomeatal line. Images of technical quality previously unobtainable are shown. Normal anatomic structures such as ventricles, cerebral peduncles, pons, cerebellum, sulci, gyri, choroid plexus, faix cerebri, and tentorium cerebelli can be demonstrated. From April 1978 through December 1978, 165 gray scale ultrasonograms of the head on 111 children younger than 2 years were performed; 63 normal and 48 abnormal patients were studied, with hydrocephalus of avrious etiologies the most common abnormality. Porencephalic cysts, developmental anomalies, intraventricular and intracerebral hemorrhages, cephalohematoma, subdural hematomas, and arteriovenous malformations were demonstrated. Because of its safety and relatively low cost, ultrasonography proved to be an excellent method for following ventricular size and shunt function.

Brain↗
PubMed1979

Membranous laryngotracheobronchitis (membranous croup).

Membranous laryngotracheobronchitis (membranous croup), not previously described as a distinct entity, is characterized by diffuse inflammation of the larynx, trachea, and bronchi with adherent or semiadherent mucopurulent membranes in the subglottic trachea (conus elasticus) and in the upper trachea distal to the conus elasticus. We reviewed 28 cases of membranous croup diagnosed by endoscopy and/or radiographic examination. The importance of the recognition of membranous croup as a distinct entity is discussed. The characteristic radiologic findings consist of subglottic tracheal narrowing, irregularity of contour of the proximal tracheal mucosa, and sometimes detached or partially detached proximal tracheal membranes, which can be mistaken for tracheal foreign bodies.

Bronchitis↗
PubMedDate not supplied

Uncommon causes of scrotal and inguinal swelling in children: sonographic appearance.

Sonography has proven to be a useful diagnostic tool in the evaluation of scrotal abnormalities. Three uncommon, interesting abnormalities--epididymoorchitis as the presenting manifestation of Hemophilus influenzae sepsis, torsion of undescended testis, and abdominoscrotal hydrocele--are presented. All had swelling of both the scrotum and the inguinal area. Sonography played a significant role in the evaluation and management of these patients.

Child↗
PubMedDate not supplied

The length of the polyoxyethylene chain in the Triton X detergents modulates the apparent activation of neurosteroid sulfatase in bovine brain.

The effect of the Triton X series on the solubilization and enzyme activity of neurosteroid sulfatase (NSS) in the bovine midbrain was investigated. Triton X-100 and X165 stimulated NSS activity in the bovine midbrain, while Triton X-305 did not. This apparent activation was attributed to the action of the detergents, and not to the latency of the enzyme or the removal of some inhibitory substance from the microsomes. The maximum stimulation was obtained when the length of the polyoxyethylene chain of the detergent was 16.

Animals↗
PubMedDate not supplied

Spatial distribution of mammalian cells grown on macroporous microcarriers with improved attachment kinetics.

Vero and HepG2 cells were cultivated on macroporous gelatin microcarriers prepared by the calcium carbonate inclusion method. Cell attachment to these microcarriers was slow. For HepG2 cells the subsequent growth was poor. Modification of the microcarriers by incorporation of (diethylamino)ethyl-HCl improved HepG2 attachment and subsequent growth. Optical sectioning with confocal microscopy allowed visualization of the distribution of cells within microcarriers. In most microcarriers, cells were found to preferentially populate regions close to the external surface and some cavities in the interior. Despite the incomplete occupancy of the interior of the microcarriers, high cell concentrations were achieved.

Animals↗
PubMedDate not supplied

Spectrum of neurogenic tumors in the thorax: CT and pathologic findings.

Neurilemomas and neurofibromas appear as round soft tissue masses at CT. Variable enhancement with either homogeneity or heterogeneity is seen in neurilemomas. Attenuation of the tumors on enhanced CT depends on histology: the extent of Antoni A or B tissue and the amount of myxoid or cystic degeneration or hemorrhage. Neurofibromas are usually homogeneous low attenuation lesions on unenhanced CT. They show homogeneous enhancement or early central blush on enhanced scan. The extent of enhancement depends on the proportions of tumor components: nerve sheath cells, collagen bundles, and areas of myxoid degeneration. Malignant nerve sheath tumors show variable attenuation. Bony destruction, pleural effusion, and metastatic pulmonary nodules may also occur. Ganglioneuromas appear as oblong homogeneous low attenuation lesions on both enhanced and unenhanced CT. This low attenuation is due to their pathologic components, with an abundant amount of myxoid matrices and a relatively small amount of ganglion cells. Neuroblastomas appear as aggressive soft tissue lesions with calcification. Ganglioneuroblastomas may appear with features in between those of ganglioneuromas and neuroblastomas. The typical location of the posterior mediastinum or the aortopulmonary window and high enhancement with administration of contrast medium at CT suggest the diagnosis of paragangliomas.

Adult↗
PubMedDate not supplied

Squalene-induced extrinsic lipoid pneumonia: serial radiologic findings in nine patients.

PURPOSE: The purpose of this work was to demonstrate the initial and follow-up radiologic findings of squalene-induced extrinsic lipoid pneumonia. METHOD: Follow-up chest radiographs (n = 9) and high-resolution CT scans (n = 3) as well as initial radiographs (n = 9) and CT scans (n = 8) were obtained in nine patients with squalene-induced extrinsic lipoid pneumonia. The serial radiologic findings were analyzed retrospectively by three chest radiologists, focusing on the pattern and distribution of parenchymal abnormalities. RESULTS: The most frequent pattern of parenchymal abnormalities on chest radiograph was areas of ground-glass opacity (n = 9, bilateral 6), followed by consolidation (n = 7, bilateral 3) and poorly defined small nodules (n = 4, bilateral 2). The abnormalities were distributed in the right lower lung (n = 9), left lower lung (n = 6), and right middle lung (n = 6) zones. Initial CT scans (n = 8) demonstrated bilateral areas of ground-glass attenuation (n = 8), poorly defined centrilobular nodules (n = 8), crazy paving (n = 6), and consolidation (n = 3). The abnormalities were distributed in the right middle lobe (n = 8) and in both lower lobes (n = 5). Follow-up chest radiograph (n = 9) showed complete disappearance (n = 2) and decrease (n = 7) in the extent of the parenchymal abnormalities. Follow-up CT scans (n = 3) demonstrated decrease (n = 2) and no change (n = 1) in the extent of the abnormalities. CONCLUSION: Squalene-induced extrinsic lipoid pneumonia most commonly appears as areas of ground-glass attenuation mixed with poorly defined centrilobular nodules and crazy paving on CT, being distributed mainly in the right middle and both lower lobes. The lesions are indolent and remain after cessation of squalene ingestion.

Adolescent↗
PubMedDate not supplied

Focal cortical dysplasia: comparison of MRI and FDG-PET.

PURPOSE: The purpose of this work was to compare the use of MRI and [18F]fluorodeoxyglucose (FDG) positron emission tomography (PET) in the diagnosis of focal cortical dysplasia (FCD). METHOD: Nineteen patients with surgically proven FCD were analyzed retrospectively. MRI was performed in all patients, and FDG-PET was performed in 17 patients. We compared the MR and FDG-PET findings of FCD according to the histologic findings that were classified into three grades. RESULTS: Four cases were classified as Grade I, 4 cases as Grade II, and 11 cases as Grade III FCD. The lesions were detected on MRI in 9 (82%) of the 11 patients with Grade III FCD and in only 1 (13%) of the 8 patients with Grade I and II FCD. Cortical hypometabolism of the lesion was revealed on FDG-PET in 6 (86%) of the 7 patients with Grade I and II FCD and in 9 (90%) of the 10 patients with Grade III FCD. The extent of the cortical abnormality was larger on FDG-PET than on MRI in 11 (65%) of the 17 patients. CONCLUSION: FDG-PET is more useful in delineating the cortical abnormality in patients with mild degrees of FCD. The extent of the lesion was larger or similar on FDG-PET compared with that of the MRI.

Adolescent↗