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Biomedical subjects

B K Han

Publications and source records attributed to B K Han.

At least 55 records · Page 3Linked to original sources
PubMed1989

Nuclear cystography and renal sonography: findings in girls with urinary tract infection.

This retrospective study documents the findings on nuclear cystography and renal sonography of 455 girls who had urologic imaging for a proved urinary tract infection (UTI). Nuclear cystograms were normal in 313 (69%) of 455 patients. Vesicoureteral reflux was seen in 142 patients (31%): six with grade I, 90 with grade II, 43 with grade III, and three with grade IV. Twelve percent of patients with vesicoureteral reflux had renal parenchymal scars. Increasing grades of reflux were associated with an increase in the severity and number of parenchymal scars. Normal renal sonograms were seen in 83% of patients. Abnormalities noted on sonograms included parenchymal scarring in 31 (7%) of the 455 patients, anomalies in 19 patients (4%), mild to moderate dilatation of the renal pelvis and or ureters in 45 patients (10%), and bladder wall thickening in 45 patients (10%).

Adolescent↗
PubMed1989

Brain abnormalities in infants on extracorporeal membrane oxygenation: sonographic and CT findings.

The findings of cranial sonography performed before and during extracorporeal membrane oxygenation (ECMO) in 50 near-term infants and CT findings after ECMO in 18 of those patients are reported. Hemorrhage is uncommon in patients being considered for ECMO: subependymal hemorrhage was seen in one case and subependymal cyst possibly due to in utero hemorrhage was seen in five cases. Hypoxic ischemic ischemic injury is more common: severe cerebral edema was seen in two cases, occipital hemorrhagic infarct in one case, and mild cerebral edema in 17 cases. During ECMO, sonograms showed that the hemorrhage in patients with small subependymal hemorrhage or cyst before ECMO did not extend while on ECMO. Typical germinal matrix/intraventricular hemorrhage was seen uncommonly (three cases). Unusual parenchymal hemorrhage did occur. Hypoxic ischemic brain injury was more common: parenchymal hemorrhage was seen in three cases, severe cerebral edema in three cases, and infarction in three cases. Hypoxic ischemic brain injury probably occurs before ECMO, with a delay in visualization. CT after ECMO detected additional abnormalities, particularly peripheral areas of hemorrhage and infarction not visible on sonograms, and is now being performed on all patients. More emphasis should be placed on better screening of infants being considered for ECMO treatment to identify irreversible anoxic brain injury, not just hemorrhage.

Brain Diseases↗
PubMed1988

Bony inlet stenosis as a cause of nasal airway obstruction.

Two cases of congenital bony stenosis of the nasal piriform aperture (anterior nares) are presented. Both patients experienced episodes of respiratory distress and clinical symptoms similar to those seen in patients with posterior choanal atresia. The underlying anatomic abnormalities in congenital bony inlet stenosis are quite different from those in choanal atresia and require different surgical approaches for correction. Computed tomography demonstrates in detail the underlying anatomic abnormality and allows differentiation of bony inlet stenosis from choanal atresia.

Choanal Atresia↗
PubMed1988

Sonographic findings in infants with macrocrania.

This study compares the sonographic and CT findings in a group of infants with macrocrania and correlates those findings with neurologic outcome to determine the diagnostic accuracy and prognostic value of sonography. Sonographic findings in 255 infants with macrocrania are described. Of the 195 term infants examined, 130 had normal sonograms, 11 (5.6%) had significant abnormalities, and 54 had increased intra- and/or extraaxial fluid spaces. Of the 60 former preterm infants, 33 had normal sonograms, four (6.7%) had significant abnormalities, and 23 had increased fluid spaces or small resolving germinal matrix hemorrhages. The patients with significant abnormalities usually had head circumferences greater than the 95th percentile and had neurologic abnormalities. There was good correlation between sonography and CT in 30 of the 36 patients evaluated by both. In six there was mild discrepancy in the volume of the extraaxial fluid. No significant abnormality was missed by sonography. CT did not contribute any additional information. Neurologic follow-up was available for 202 patients. Nineteen percent of the term infants and 24% of the former preterm infants were abnormal on neurologic follow-up. Most patients with normal sonograms were normal on follow-up. Twelve of the term and four of the preterm infants with normal sonograms were developmentally delayed on follow-up. Increased CSF in the ventricles and/or extraaxial spaces was a common abnormality, but it usually is associated with a normal neurologic outcome and represents "benign macrocrania." We conclude that an infant with an enlarged or enlarging head should have a neurologic examination and head circumference measurement. If the patient has a head circumference greater than the 95th percentile, particularly if there are abnormal neurologic findings, further evaluation is indicated. Sonography is the initial procedure recommended since it accurately evaluates ventricular size, extraaxial fluid, and congenital malformations. If sonography is normal or shows mildly increased fluid spaces, then follow-up head circumference measurement and clinical evaluation will probably suffice. CT is indicated if there is a significant abnormality on sonography that requires further clarification.

Brain↗
PubMed1986

Multiple hamartomas associated with intracranial malformation.

We examined a newborn infant with multiple hamartomas, including an epidermal nevus syndrome and a giant pigmented congenital nevocellular nevus, associated with other structural developmental abnormalities such as nevus flammeus, vascular malformation, cutis aplasia congenita of the scalp, cartilage hamartoma, and a lipodermoid of the conjunctiva. This child had a significant brain malformation, diagnosed by sonography and computerized tomography, consisting of a significant enlargement of the left hemisphere not associated with asymmetry of the skull or facial bones. We suggest a careful investigation of the intracranial structures by computerized tomography and/or ultrasonography in case of either extensive linear nevus sebaceous sequence and/or giant pigmented nevocellular nevus.

Adult↗
PubMed1986

Postseptal cellulitis: CT in diagnosis and management.

Thirteen orbital computed tomographic (CT) scans were obtained in 12 patients with postseptal (orbital) cellulitis. Sinus radiographs, which were also obtained, were not helpful in diagnosis or management. The location and extent of the inflammatory process was accurately demonstrated with axial CT scans in all cases. A protocol using CT in the management of postseptal cellulitis is proposed.

Adolescent↗
PubMed1986

Sonography of neck masses in children.

The sonograms and medical records of 49 patients were reviewed to determine if there is a characteristic sonographic appearance for certain neck masses. Neck masses included: inflammatory masses (12), noninflammatory masses (23), and thyroid masses (14). Four entities including thyroglossal duct cyst, fibromatosis colli, cystic hygroma, and multiple lymphadenopathy showed characteristic sonographic appearance. Thyroglossal duct cysts were seen as midline or slightly off midline cystic masses. A sinus tract extending superiorly was nicely demonstrated in one patient. The mass in fibromatosis colli (neonatal torticollis) appeared as a well defined mass clearly within the sternocleidomastoid muscle, uniformly echogenic, but less echogenic than the normal surrounding muscle, without good through-transmission. A cystic or primarily cystic mass with linear septations was the characteristic finding of the cystic hygroma. Multiple lymphadenopathy demonstrated multiple discrete, oval, relatively hypoechoic masses along the cervical lymphatic chain. The sonographic appearance of inflammatory masses was variable, being either inhomogeneously echogenic or of mixed echogenicity. Hemangiomas were either echogenic with cystic vascular spaces or linear septations or relatively homogeneously echogenic. Intrinsic thyroid masses could be distinguished from extrinsic masses in most cases. The demonstration of calcification in a mass was useful in narrowing the differential diagnosis. Although it is not a specific finding, the presence of calcification highly suggests a neoplastic lesion, particularly neuroblastoma or teratoma. Not only can the location, extent, and internal characteristics of a mass be determined, but in certain entities, the sonographic appearance is characteristic and an accurate diagnosis can be made.

Adolescent↗
PubMed1985

Bacterial meningitis in infants: sonographic findings.

A retrospective study was performed on 78 patients (newborn to 2 years old) with clinically proved bacterial meningitis. Sonograms were obtained during the acute illness and medical records were reviewed. The spectrum of sonographic features of meningitis included normal scans (30 patients), ventriculomegaly (11 patients), echogenic sulci (31 patients), extra-axial fluid collections (26 patients), abnormal parenchymal echogenicity (9 patients), evidence of ventriculitis (5 patients), and brain abscess (1 patient). In 46 patients, correlation between the sonographic findings and neurologic outcome on clinical follow-up (6 months to 4 years) was made. Findings of abnormal parenchymal echogenicity and/or moderate-to-marked ventriculomegaly were associated with significant neurologic sequelae; however, echogenic sulci and small extra-axial fluid collections did not appear to have any prognostic significance. Twenty-nine of the 78 patients had sonography without clinical indication of complications of meningitis, and in no patient was a significant abnormality found. Our study suggests that sonography is indicated only when there is clinical suspicion of complications.

Acute Disease↗
PubMed1985

Renal transplants in children: long-term follow-up using sonography.

Sonographic findings more than 1 year after transplantation for 16 children with renal transplants were reviewed to determine the appearance of the transplant on long-term follow-up and to correlate its sonographic appearance with its function. The appearance of the transplant varied considerably, and there was no association between renal function and renal volume, shape, parenchymal echogenicity, or central sinus echoes. Renal size and donor age were negatively associated. In children, a change in renal size greater than the usual 90%-130% of baseline volume seen in adults is a normal adaptation of the transplanted kidney to the recipient body size. Sonography was not useful for diagnosing chronic rejection or predicting function in the pediatric transplant patient.

Adolescent↗
PubMed1985

Sonographic measurements and appearance of normal kidneys in children.

In 122 children (ages, newborn to 17 years) without urinary tract disease, 244 kidneys were examined sonographically. Renal length and volume were measured and correlated with age, body weight, height, and total body surface area, permitting preparation of nomograms with predicted means and 95% prediction intervals. Also evaluated were renal parenchymal echogenicity, medullary pyramids, and central sinus echoes, and the appearance of each was correlated with age.

Adolescent↗
PubMed1984

Renal transplant rejection: sonographic evaluation in children.

The ability to detect renal rejection sonographically was studied in 42 pediatric renal transplant patients over a 33-month period. Sonography was not helpful in detecting rejection when the donor was less than five years of age. When the donor was over five years of age, a combination of sonographic findings allowed detection of rejection with a greater specificity than has been reported previously. The combination of three or more of the sonographic findings (increased renal volume 30% over the baseline value; enlarged, broadened, rectangular medullary pyramids [rays]; a reduction or absence of the central sinus echoes, and altered echogenicity in the renal parenchyma) indicated rejection with 97% specificity and 58% sensitivity. Radionuclide imaging with Tc-99m DTPA gave approximately the same sensitivity (60%) but was less specific (88%). By excluding rejection with the absence of the sonographic findings, it was possible to suggest acute tubular necrosis in some patients. It was also possible to detect the complications of renal transplantation, but sonography did not detect small ruptures of the kidney as a part of the rejection phenomenon.

Adolescent↗