Search PubMed⌕ Search

Biomedical subjects

B K Han

Publications and source records attributed to B K Han.

At least 19 recordsLinked to original sources
PubMed2000

Metaplastic carcinoma of the breast: mammographic and sonographic findings.

PURPOSE: We investigated the mammographic, sonographic, and pathologic findings in metaplastic carcinoma of the breast. METHODS: The mammographic (n = 16) and sonographic (n = 11) findings in 16 patients with metaplastic carcinoma of the breast were analyzed retrospectively along with pathologic findings. Whenever possible, results of preoperative fine-needle aspiration biopsy and immunohistochemical studies were obtained. RESULTS: All patients presented with a palpable breast mass. The mean size of the lesions at pathologic examination was 4.2 cm. On mammography, 15 patients had a mass (1 patient had 2 masses), and 1 patient had only clustered microcalcifications without an associated mass. The mean longest diameter of the 16 masses on mammography was 4.6 cm. Eleven lesions (69%) were round to ovoid in shape, 13 lesions (81%) showed ill-defined or obscured margins, and 10 lesions (63%) showed associated architectural distortion. On sonography, 6 (55%) of 11 lesions were round to ovoid, 9 lesions (82%) had well-defined margins, and 6 lesions (55%) showed complex echogenicity with solid and cystic components. At pathologic examination, 4 of these 6 lesions showed hemorrhagic or cystic necrosis. Axillary lymph nodes were positive in 6 (40%) of 15 patients in whom axillary node dissection was performed. CONCLUSIONS: Metaplastic carcinoma of the breast manifests as a rapidly growing, mammographically ill-defined round mass with associated architectural distortion on mammograms. Complex echogenicity with solid and cystic components may be seen sonographically and is related to hemorrhagic or cystic necrosis seen pathologically.

Adult↗
PubMed2000

Subunits of neurosteroid sulfatase from bovine brain.

We have purified the neurosteroid sulfatase (NSS) from Triton X-100 solubilized microsomes of bovine brain about 100-fold. The purified enzyme is composed of two catalytic units (MW: 57 kDa) and two regulatory units (MW: 38 kDa), making it an alpha(2)beta(2) heterotetramer, whose apparent molecular weight was 180 kDa by gel filtration in the presence of Triton X-100.

Animals↗
PubMed2000

Infantile fibromatosis in childhood: findings on MR imaging and pathologic correlation.

AIM: The objective of this study was to analyse the MR imaging findings of infantile fibromatosis of childhood and to correlate them with histopathological features. MATERIALS AND METHODS: Seven patients with histologically proven infantile fibromatosis were included in this study. The findings on MR images were retrospectively evaluated and then correlated with the pathological features. Findings on MR imaging evaluated included signal intensity, extent of hyperintense area on T2-weighted images, margins of the lesion, the degree and pattern of enhancement and the presence of fatty tissue. Pathological features evaluated included cellularity, collagenization, and myxoid change. A five point scale was used for the evaluation of the extent of hyperintense area on MR imaging, and each of pathological features. RESULTS: On T1-weighted images, the lesions were iso-intense in two patients; iso- and hypointense in three; and iso-, hypo- and hyperintense in two. On T2-weighted images, iso-, hypo- and hyperintense areas were mixed in all patients, the hyperintense area being the largest portion of the lesion. The margins of the lesions were infiltrative in four patients (57%), smooth in two (29%) and mixed in one (14%). Enhancement was marked in five patients (72%) and diffuse in five (71%). Regardless of the hyperintense signal intensity on T2-weighted images, the grades of each pathologic feature were variable. CONCLUSION: Infantile fibromatosis on MR imaging causes an enhancing mass, that is largely hyperintense on T2-weighted images. Areas of high signal intensity on T2-weighted images corresponded to variable grades of cellularity, collagenization, or myxoid change.

Child↗
PubMed2000

Choledochal cyst: comparison of MR and conventional cholangiography.

AIMS: To assess the diagnostic value of magnetic resonance (MR) cholangiography versus conventional cholangiography in patients with choledochal cyst and to determine whether MR cholangiography can be considered an alternative to conventional cholangiography. MATERIALS AND METHODS: Thirteen patients with choledochal cyst were examined by MR cholangiography and conventional cholangiograms. Magnetic resonance cholangiography employed T2-weighted axial and coronal fast spin-echo, single and multislab single-shot fast spin-echo sequences, including source images with maximum intensity projections. The diagnostic value of MR cholangiography and conventional cholangiograms was assessed and compared using the criteria of depiction of morphology, anomalous pancreaticobiliary duct union and demonstration of complications such as stones. A four-point diagnostic scale was applied to the delineation of the ductal anatomy with the Wilcoxon signed-ranks test and McNemar's test used for statistical analysis. RESULTS: The depiction of the choledochal cyst was significantly better with MR cholangiography than with conventional cholangiography (P = 0.03). The detection rate of an anomalous pancreaticobiliary duct union was not significantly different with either method (P = 0.641), nor was the detection rate of bile duct stones (P = 0.375). CONCLUSION: Magnetic resonance cholangiography provides data equivalent to or superior to those from conventional cholangiography in evaluating choledochal cyst. Magnetic resonance cholangiography is recommended as a non-invasive examination of choice for the evaluation of choledochal cyst.

Adult↗
PubMed2000

Thoracic manifestation of Churg-Strauss syndrome: radiologic and clinical findings.

STUDY OBJECTIVES: To describe the radiologic and clinical findings of Churg-Strauss syndrome (CSS) and its thoracic manifestations. DESIGN: We used retrospective analysis to review and characterize the radiographic, thin-section CT, and clinical findings of CSS. PATIENTS: The study involved nine patients with CSS. The patients included four men and five women, whose ages ranged from 18 to 60 years (median, 35 years). Thin-section CT scans and chest radiographs were retrospectively analyzed by three radiologists in consensus. Clinical data were obtained by chart review. Histologic samples were available in eight patients. RESULTS: All patients had a history of asthma averaging 28 months (range, 4 to 72 months) prior to the initial symptom of vasculitis and marked peripheral blood eosinophilia (mean peak count, 8,726/microL; range, 3,000 to 32,000/microL; mean differential count, 41%; range, 19 to 67%). All patients had systemic vasculitis involving the lung and two to four extrapulmonary organs, most commonly the nervous system (n = 8) and skin (n = 7). Chest radiographs showed bilateral nonsegmental consolidation (n = 5), reticulonodular opacities (n = 3), bronchial wall thickening (n = 3), and multiple nodules (n = 1). The most common thin-section CT findings included bilateral ground-glass opacity (n = 9); airspace consolidation (n = 5), predominantly subpleural and surrounded by the ground-glass opacity; centrilobular nodules mostly within the ground-glass opacity (n = 8); bronchial wall thickening (n = 7); and increased vessel caliber (n = 5). Other findings were hyperinflation (n = 4), larger nodules (n = 4), interlobular septal thickening (n = 2), hilar or mediastinal lymph node enlargement (n = 4), pleural effusion (n = 2), and pericardial effusion (n = 2). CONCLUSIONS: In CSS, thoracic organs are invariably involved with additional diverse manifestations. The possibility of CSS should be raised in patients with a history of asthma and hypereosinophilia who present with thin-section CT findings of bilateral subpleural consolidation with lobular distribution, centrilobular nodules (especially within the ground-glass opacity) or multiple nodules, especially in association with bronchial wall thickening.

Adolescent↗
PubMed2000

MR angiography of moyamoya disease before and after encephaloduroarteriosynangiosis.

OBJECTIVE: Our purpose was to evaluate the usefulness of MR angiography in revealing moyamoya disease before and after encephaloduroarteriosynangiosis. SUBJECTS AND METHODS: Twenty-six patients (51 hemispheres) with angiographically confirmed moyamoya disease who underwent encephaloduroarteriosynangiosis were included in the study. Findings on preoperative MR angiography were compared with those on conventional angiography. Postoperative neurologic status was categorized as poor, fair, good, or excellent. Postoperative MR angiography was examined for the appearance of the superficial temporal artery, changes in moyamoya vessels, and transdural collateral vessels into the middle cerebral artery territory. RESULTS: Preoperative MR angiography revealed moyamoya disease in all patients (diagnostic accuracy, 100%). MR angiography correctly depicted the degree of internal carotid artery stenosis in 37 arteries (73%), moyamoya vessels in 33 hemispheres (65%), and the degree of stenosis in the middle, anterior, and posterior cerebral arteries in 125 (82%) of 153 arteries. After surgery, 39 hemispheres showed an excellent outcome, eight showed a good outcome, two a fair outcome, and two a poor outcome. On postoperative MR angiography, vascular supply to the middle cerebral artery territory via transdural collateral vessels increased in 28 hemispheres (55%) and decreased in four (8%). The size of the superficial temporal artery increased in 41 (80%) of 51 hemispheres. The extent of moyamoya vessels decreased in 27 hemispheres (53%) after surgery. CONCLUSION: MR angiography can show the changes in the superficial temporal artery and development of transdural collateral vessels after encephaloduroarteriosynangiosis. Because MR angiography is noninvasive, it is valuable for evaluating postoperative changes.

Adolescent↗
PubMed2000

Takayasu's arteritis: assessment of disease activity with contrast-enhanced MR imaging.

OBJECTIVE: The purpose of this study was to evaluate the role of contrast-enhanced MR imaging in the determination of disease activity in patients with Takayasu's arteritis. SUBJECTS AND METHODS: High-resolution contrast-enhanced T1-weighted spinecho MR imaging using small fields of view (14-20 cm) and thin slices (4-5 mm) was performed in 26 patients with Takayasu's arteritis and 16 healthy subjects. The degree of aortic mural enhancement was assessed by measuring signal intensity and by visually estimating it in comparison with that of the myocardium. RESULTS: Contrast-enhanced MR imaging showed more enhancement of thickened aortic wall compared with myocardium, thus suggesting active Takayasu's arteritis on MR imaging in 16 patients. Determination of disease activity using contrast-enhanced MR imaging was concordant with clinical findings in 23 patients (88.5%). Contrast-enhanced MR findings were concordant with laboratory findings in most patients (erythrocyte sedimentation rate in 92.3% [24/26] and C-reactive protein in 84.6% [22/26]). The measured signal intensity of the aortic wall relative to that of myocardium during the early phase of contrast-enhanced MR imaging correlated well with the erythrocyte sedimentation rate (r = 0.78, p < 0.005) and with the C-reactive protein level (r = 0.63, p < 0.005). CONCLUSION: Contrast-enhanced MR imaging provides information about disease activity of Takayasu's arteritis, which may be useful in the diagnosis and treatment of Takayasu's arteritis.

Adolescent↗
PubMed2000

Metastatic tumors to the breast: mammographic and ultrasonographic findings.

We evaluated the mammographic (n = 16) and ultrasonographic (n = 15) findings of 18 patients with metastatic breast carcinoma. Fifteen patients showed multiple or diffuse lesions and three patients showed single lesions. Ten patients (55.6%) had bilateral lesions. Mammography revealed high density (15 cases, 93.8%), round to oval (11 cases, 68.8%) lesions with poorly defined or obscured margins (12 cases, 75.0%). No associated calcification was found in any lesion. Ultrasonographically, poorly defined (8 cases, 53.3%), irregularly shaped (8 cases, 53.3%), hypoechoic (14 cases, 93.3%), heterogeneous (8 cases, 53.3%) lesions were predominantly distributed superficially (11 cases, 73.3%). Axillary lymphadenopathy was detected in six patients (33.3%). The longest diameter of most of the lesions was less than 2.0 cm (13 cases, 81.3%). We conclude that metastatic tumors to the breast appear as relatively small, superficially located, poorly defined, irregular nodules without calcification on mammography and ultrasonography. However, when the metastatic lesion is diffuse, the appearance is indistinguishable from that of inflammatory breast carcinoma.

Adolescent↗
PubMed1999

Developmental intervention for preterm infants diagnosed with periventricular leukomalacia.

Preterm infants with periventricular leukomalacia (PVL) were evaluated to determine whether multi-sensory stimulation is safe and to assess whether it improved neurobehavior and neurodevelopment. Thirty preterm infants with documented PVL were randomly assigned to control (n= 15) or experimental (Group E) (n= 15) groups at 33 weeks post-conceptional age. Group E infants received 15 minutes of auditory, tactile, visual, and vestibular (ATVV) intervention twice a day, five days a week, for four weeks during hospitalization. Repeated measures ANOVA demonstrated that Group E infants experienced significant increases in heart and respiratory rate and a 0.72% drop in hemoglobin saturation, coinciding with a significant behavioral state shift from sleep to alertness during intervention. No differences were identified in neurobehavioral function and neurodevelopment, indicating that Group E suffered no injury. Group E had an average hospital stay nine days shorter than that of controls, with the associated cost savings of $213,840. The earlier hospital discharge indicates that ATVV intervention promotes alertness without compromising physiologic status in vulnerable infants.

Analysis of Variance↗
PubMed1999

MRI of primary meningeal tumours in children.

Childhood meningeal tumours are uncommon and mostly meningiomas. We reviewed the histological and radiological findings in meningeal tumours in six children aged 12 years or less (four benign meningiomas, one malignant meningioma and one haemangiopericytoma). Compared to the adult counterpart, childhood meningiomas showed atypical features: cysts, haemorrhage, aggressiveness and unusual location. MRI features varied according to the site of the tumour, histology, haemorrhage, and presence of intra- or peritumoral cysts. Diagnosis of the extra-axial tumour was relatively easy in two patients with meningiomas, one malignant meningioma and one haemangiopericytoma. MRI findings strongly suggested an intra-axial tumour in two patients with benign meningiomas, because of severe adjacent edema. Awareness of the variable findings of childhood meningiomas and similar tumours may help in differentiation from brain tumours.

Brain↗
PubMed1999

Granulomatous mastitis: mammographic and sonographic appearances.

OBJECTIVE: The objective of our study is to describe the mammographic and sonographic appearances of granulomatous mastitis. CONCLUSION: Granulomatous mastitis can mimic breast carcinoma clinically and mammographically, but the sonographic appearance of multiple clustered, often contiguous tubular hypoechoic lesions that are sometimes associated with a large hypoechoic mass should suggest the possibility of granulomatous mastitis.

Adult↗
PubMed1999

Benign papillary lesions of the breast: sonographic-pathologic correlation.

We reviewed the sonographic findings of 42 benign papillary lesions of the breast and correlated them with pathologic findings. Sonography detected 95% of papillomas (22 intraluminal masses, four extraductal masses, nine purely solid masses, and five mixed type masses). The sonographic margins of the mass were well defined in 20 lesions and poorly defined in 14 lesions. Poorly defined margins on sonography were frequent in papillomas with pathologic pseudoinvasion and in juvenile papillomatosis. Most benign papillary lesions of the breast have the sonographic findings suggestive of intraductal origin. The sonographic findings of papillary lesions correlated well with pathologic findings.

Adolescent↗
PubMed1998

Epidemic adenoviral lower respiratory tract infection in pediatric patients: radiographic and clinical characteristics.

OBJECTIVE: This retrospective study was undertaken to evaluate the radiographic and clinical findings of adenoviral lower respiratory infection during an epidemic period. CONCLUSION: Epidemic adenoviral pneumonia may mimic bacterial pneumonia on radiographs. Findings that include bilateral and multifocal involvement on chest radiographs, normal or decreased WBC associated with lymphocytosis, and progression of illness despite extensive antibiotic therapy, help to differentiate epidemic adenoviral from bacterial pneumonia.

Adenovirus Infections, Human↗
PubMed1997

Cranial ultrasound and CT findings in infants with hypernatremic dehydration.

We present two newborn infants with hypernatremic dehydration with central nervous system (CNS) involvement. Both patients showed similar imaging findings, demonstrating generalized brain parenchymal abnormality and multifocal areas of hemorrhage or hemorrhagic infarction. These findings are compatible with previously described CNS pathologic findings in hypernatremia.

Brain↗
PubMed1997

Distribution and characterization of neurosteroid sulfatase from the bovine brain.

We investigated the regional and subcellular distribution of neurosteroid sulfatase (NSS) in the bovine brain and its enzymatic properties by using dehydroepiandrosterone sulfate (DHEA-S) as a substrate. Bovine NSS was highly concentrated in the region of the midbrain and in the hypothalamus. The enzyme was found to be a microsomal enzyme. The optimal temperature of the enzyme was 50 degrees C, which was slightly lower than that of other steroid sulfatases. The optimal pH of bovine NSS was 7.4 with a second optimum at pH 4.0. The second optimal pH of 4.0 was the most characteristic property of bovine NSS. Employing DHEA-S as the substrate, apparent Km and Vmax values were 113 +/- 21 microM and 4.1 +/- 0.4 nmol/mg protein/h, respectively, whereas Km and Vmax values were found to be 1.6 +/- 0.2 M and 1.9 +/- 0.3 micromol/mg protein/h with p-nitrophenyl sulfate (NP-S) as the substrate. NSS has thus been shown to have a higher affinity for the steroid sulfate than the phenolic compound. When DHEA-S was used as the substrate, pregnenolone sulfate (Preg-S) was a competitive inhibitor with an apparent Ki value of 46 microM, and NP-S was a non-competitive inhibitor (apparent Ki=12 mM).

Animals↗
PubMed1997

Pericaval fat collection that mimics thrombosis of the inferior vena cava: demonstration with use of multi-directional reformation CT.

PURPOSE: To evaluate the causes for localized fat collection that seemed to be within the subdiaphragmatic inferior vena cava (IVC) on axial computed tomographic (CT) scans. MATERIALS AND METHODS: Six consecutive patients with presumed intracaval fat collection at routine abdominal CT (n = 2) or thin-section CT of the lung (n = 4) were studied prospectively with helical CT. Three patients had chronic liver diseases. Multi-directional, two-dimensional, reformatted images were obtained from the helical CT data for identification of the relation between the IVC and fat collection. Six patients without intracaval fat collection were studied as control subjects. RESULTS: On axial CT scans, the fat collection had a round or oval shape (in four of six patients) and was located posteromedial to the IVC (in four of six patients). On coronal reformatted images, the fat collection was outside the IVC between the diaphragm and subdiaphragmatic IVC, which was contiguous to the fat around the subdiaphragmatic esophagus. In the fat collection group, the IVC angled toward the right and narrowed to half in diameter as it passed down to the diaphragm. In the control group, the IVC was straight, although the diameter decreased similarly. CONCLUSION: A localized fat collection adjacent to the subdiaphragmatic IVC that mimics intracaval fat on axial CT scans is due to acute angulation of the IVC, which is probably a result of anatomic variation, chronic liver disease, or both.

Adipose Tissue↗