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Hyun Woo Goo

Publications and source records attributed to Hyun Woo Goo.

At least 19 recordsLinked to original sources
PubMed2006

Left ventricular noncompaction in an infant: use of non-ECG-gated cardiac CT.

We report an infant who had left ventricular dysfunction of unknown etiology and was diagnosed with left ventricular noncompaction by non-ECG-gated cardiac CT. This relatively rare diagnosis, an unclassified cardiomyopathy, was confirmed by retrospective review of echocardiography on which the diagnosis had initially been missed. As in echocardiography, CT was capable of delineating the characteristic two-layered myocardium of the left ventricle with the most severe involvement of the apical segment.

Cardiomyopathies↗
PubMed2006

Whole-body MRI of Langerhans cell histiocytosis: comparison with radiography and bone scintigraphy.

BACKGROUND: In Langerhans cell histiocytosis (LCH) evaluation of the extent of disease is one of the major predictors of patient outcome. Historically this is undertaken using plain radiography and bone scintigraphy. Recently, whole-body (WB) MRI has been reported to be useful in detecting skeletal and extraskeletal metastases in both adults and children. OBJECTIVE: To evaluate the usefulness of WB MRI in patients with LCH in comparison with plain radiography and bone scintigraphy. MATERIALS AND METHODS: In nine children (1-7 years of age; mean 3.3 years) who had a pathological diagnosis of LCH and had either plain radiography or bone scintigraphy for comparison, 43 WB MR examinations were performed. Skeletal and extraskeletal lesions of the disease on WB MRI were compared with those on plain radiography and bone scintigraphy. RESULTS: LCH showed unifocal single-system involvement in one patient, multifocal single-system involvement in three, and multifocal multisystem disease in five. WB MRI identified additional skeletal lesions in three (38%) of eight patients, compared with plain radiography, and in two (25%) of eight, compared with bone scintigraphy. WB MRI detected extraskeletal lesions of the disease in five (56%) of the nine patients exclusively, except for one patient whose lung lesions were also detected on plain radiography. In two patients, treatment was changed according to WB MRI findings. CONCLUSION: WB MRI is a useful initial and follow-up diagnostic method to assess the extent of LCH because WB MRI not only identifies more skeletal lesions of the disease than do plain radiography and bone scintigraphy, but also detects extraskeletal lesions of the disease.

Child↗
PubMed2006

Effectiveness of novel combination chemotherapy, consisting of 5-fluorouracil, vincristine, cyclophosphamide and etoposide, in the treatment of low-grade gliomas in children.

Low-grade gliomas (LGG), which account for about 30% of brain tumors in children, are usually treated with surgical excision and/or radiotherapy. For patients who have significant residual tumor after resection or relapse after radiation, the proper chemotherapy regimen has not yet been identified. Thirteen children diagnosed with LGG outside the cerebellum between January 1999 and December 2004, all of whom had significant residual tumor after surgical resection, relapsed after radiation or showed visual deterioration, were treated for 18 months with a multi-drug regimen of vincristine, etoposide, cyclophosphamide and 5-fluorouracil. Of the 7 patients who completed chemotherapy, 1 showed complete response (CR), 5 showed partial response (PR), and 1 had stable disease (SD). In 5 patients, chemotherapy was prematurely discontinued; 4 of these patients showed tumor progression and 1 had SD. One patient is still undergoing treatment. The side effects of chemotherapy were manageable. The median time to tumor response was 34 months (range, 2-82 months). The progression free survival was 67.3%. Pediatric LGG patients with residual tumor after surgery or who undergo relapse(s) may be successfully treated using our combination chemotherapy regimen.

Adolescent↗
PubMed2006

Coronary CT angiography and MR angiography of Kawasaki disease.

Although the incidence of coronary artery aneurysms has diminished in patients with Kawasaki disease, coronary artery involvement is still regarded as a major complication of the disease, significantly affecting morbidity and mortality. Recent technical advances in coronary CT angiography (CTA) and MR angiography (MRA) have led to the possibility of using these two imaging methods as minimally invasive alternatives to the more invasive diagnostic catheter angiography in evaluating coronary artery abnormalities, such as aneurysm, stenosis, and occlusion. In this article, we describe imaging techniques and findings of coronary CTA and MRA in Kawasaki disease.

Adolescent↗
PubMed2006

A case of PAGOD syndrome with hypoplastic left heart syndrome.

PAGOD syndrome is an extremely rare congenital malformation complex involving multiple organs. These include pulmonary artery and lung hypoplasia, diaphragm defects, omphalocele, sex reversal or ambiguous genitalia, and complex cardiac defects. Eight cases have been reported to date. We report a case of PAGOD syndrome that is manifested by right diaphragm eventration, horseshoe lung with right lung hypoplasia, hypoplastic left heart syndrome (mitral atresia, aortic atresia), scimitar syndrome, agonadism with ambiguous genitalia. A karyotype revealed normal 46-XY. This patient received a modified Norwood procedure for hypoplastic left heart syndrome as an initial palliation and bidirectional cavopulmonary anastomosis as a second stage of operation. The postoperative courses were uneventful. This patient is waiting for Fontan operation.

Abnormalities, Multiple↗
PubMed2006

The influences of tube voltage and scan direction on combined tube current modulation: a phantom study.

BACKGROUND: For the optimum application of tube current modulation in paediatric CT it is important to know the influences of different imaging parameters on it. OBJECTIVE: This phantom study was performed to evaluate the influences of tube voltage and scan direction on combined tube current modulation, which is a combination of angular and z-axis modulation. MATERIALS AND METHODS: Sixteen-slice spiral CT with combined tube current modulation was performed using four different phantoms (one adult-size anthropomorphic phantom and three cone-shaped acryl phantoms) at three different tube voltages (80, 100 and 120 kVp) and two scan directions (craniocaudal and caudocranial). Effective tube current-time product (mAs) was chosen to maintain a consistent CTDIvol for each phantom. Other parameters, including detector collimation, slice width, pitch, reconstruction algorithm, scan field of view, and scan range were identical for each phantom. Changes in CTDIvol and mAs resulting from the modulation were calculated and compared. RESULTS: Changes in CTDIvol and mAs resulting from the modulation were different among the three tube voltages. In larger phantoms the greatest reductions (-6.1+/-3.9% in CTDIvol and -12.5+/-4.0% in mAs) were obtained with 120 kVp, whereas in smaller phantoms they were obtained with 80 kVp (-2.8+/-0.9% in CTDIvol and -2.5+/-4.9% in mAs). Smaller CTDIvol (2.4+/-0.9 mGy vs. 2.5+/-1.0 mGy, P=0.017) and mAs (57.2+/-40.4 mAs vs. 61.4+/-43.2 mAs, P=0.002) were used in caudocranial scans than in craniocaudal scans with the modulation. CONCLUSION: Combined tube current modulation is influenced by tube voltage and scan direction depending on phantom profile.

Adult↗
PubMed2006

Tube current reduction in pediatric non-ECG-gated heart CT by combined tube current modulation.

BACKGROUND: Dose reduction by combined tube current modulation has not been evaluated in pediatric low-dose CT. OBJECTIVE: This study was performed to evaluate tube current reduction in non-ECG-gated heart CT angiography in children by combined tube current modulation, and to assess the effects of body weight, age, sex, and scan direction on tube current reduction. MATERIALS AND METHODS: From September 2004 to January 2005, non-ECG-gated heart CT examinations were performed with combined tube current modulation in 50 children (median age 1 year, range 1 month to 16 years; M/F 29/21) with congenital heart disease. Sixteen-slice spiral CT studies were obtained using a weight-based low-dose protocol (80 kVp, 50-160 effective mA). CT scans were obtained in the craniocaudal direction when leg veins (n=36) were used for IV injection of contrast agent and in the caudocranial direction when arm veins (n=13) were used. In one child who underwent a Fontan operation, both arm and leg veins were used. We calculated tube current reduction by combined tube current modulation and evaluated the effects of body weight, age, sex, and scan technique on tube current reduction. The quality of CT angiography images was visually evaluated by an experienced pediatric radiologist. RESULTS: Overall tube current reduction by combined tube current modulation was 15.8+/-11.1%. The reduction was variable among five body weight groups (9.3+/-7.9% for <4.9 kg, 14.3+/-9.3% for 5.0-9.9 kg, 16.4+/-12.5% for 10.0-19.9 kg, 25.8+/-9.8% for 20.0-39.9 kg, 15.9+/-12.7% for 40.0-59.9 kg) and was significantly different among the five groups (P=0.017). When eight children in the 40.0-59.9-kg group were excluded, age showed a significant positive correlation with tube current reduction (gamma=0.4, P=0.003). There was no significant difference in tube current reduction between boys and girls. Tube current reduction was significantly greater for the caudocranial scan (21.2+/-9.2%) than for the craniocaudal scan (14.2+/-11.3%) (P=0.049). All CT angiography images were of diagnostic quality. CONCLUSIONS: Combined tube current modulation reduced tube current in pediatric non-ECG-gated heart CT by 15.8% without degradation of image quality. With our CT protocol, for body weights up to 39.9 kg, age showed a significant positive correlation with tube current reduction, but there was a lower dose-saving effect in children heavier than 40 kg. Tube current reduction was not affected by sex, but was affected by scan direction.

Adolescent↗
PubMed2006

Effects of high-resolution CT of the lung using partial versus full reconstruction on motion artifacts and image noise.

OBJECTIVE: The purpose of our study was to evaluate the effects of 0.3-second high-resolution CT (HRCT) of the lung using partial reconstruction on cardiac motion artifacts and image noise. SUBJECTS AND METHODS: Thirty-seven pairs of 0.3-second (partial reconstruction) and 0.75-second (full reconstruction) HRCT images were obtained for the lower lung zone during full-inspiration breath-holding. Imaging parameters other than temporal resolution were identical for each patient. Two radiologists visually graded motion artifacts of the cardiac border, bronchi, pulmonary vessels, and fissure in the left lung on a 4-point scale (with 4 indicating no artifacts). The maximum width of motion along the left cardiac border and the area percentage of motion artifacts in the left lung were calculated. Image noise in the air and lung was also determined. Cardiac motion artifacts and image noises were compared between the two sets of CT images. RESULTS: Visual grades for the cardiac border (4 +/- 0), bronchi (3.8 +/- 0.7), pulmonary vessels (3.6 +/- 0.8), and fissure (3.9 +/- 0.5) were higher for 0.3-second images than for 0.75-second images (1.7 +/- 0.7, 2.0 +/- 1.0, 1.6 +/- 0.7, and 2.4 +/- 0.9, respectively) (p < 0.001). The maximum width of motion along the left cardiac border (0.1 +/- 0.5 mm) and the area percentage of motion artifacts in the left lung (6.7% +/- 18.4%) were smaller for 0.3-second images than for 0.75-second images (4.5 +/- 1.7 mm and 36.2% +/- 20.9%, respectively) (p < 0.001). Image noises in the air (38.0 +/- 9.2) and the lung (86.0 +/- 23.1) were greater for 0.3-second images than for 0.75-second images (35.6 +/- 9.6 and 76.0 +/- 20.3, respectively) (p < 0.01). CONCLUSION: Compared with 0.75-second HRCT using full reconstruction, 0.3-second HRCT using partial reconstruction substantially reduces cardiac motion artifacts in the lung at the expense of increasing image noise.

Adolescent↗
PubMed2006

Detection of air trapping on inspiratory and expiratory phase images obtained by 0.3-second cine CT in the lungs of free-breathing young children.

OBJECTIVE: The objective of our study was to evaluate whether 0.3-second cine CT can be used to detect air trapping in the lungs of young children. SUBJECTS AND METHODS: In 30 children (mean age, 25 months), 0.3-second cine CT was performed at six levels during 3 seconds of quiet breathing. The study population was divided into an air trapping group (n = 24) and a no-air trapping group (n = 6). Lung density was measured at an abnormal area (with or without air trapping) and an adjacent normal area on inspiratory and expiratory phase images. Lung density differences between inspiration and expiration were calculated and compared in abnormal areas (with or without air trapping) and in normal areas. Their percentages were calculated and compared between the two groups. In addition, lung density differences between abnormal and adjacent normal areas were calculated and compared between the two groups. RESULTS: Lung density differences between inspiration and expiration were smaller in areas with air trapping (mean +/- SD, -19 +/- 34 H) than in abnormal areas without air trapping (138 +/- 36 H) (p < 0.001) or in normal areas (111 +/- 49 H) (p < 0.001). Their percentages were smaller in the group with air trapping (-27% +/- 54%) than in the group with no air trapping (120% +/- 87%) (p < 0.001). In the group with air trapping, lung density differences were larger at the expiratory phase (260 +/- 77 H) than at the inspiratory phase (129 +/- 69 H) (p < 0.001), but did not change through the respiratory cycle in the group with no air trapping (p > 0.05). CONCLUSION: Air trapping can be accurately detected in the lungs of free-breathing young children using 0.3-second cine CT.

Bronchi↗
PubMed2005

Neonatal hypoglycaemic encephalopathy: diffusion-weighted imaging and proton MR spectroscopy.

We report two infants with neonatal hypoglycaemic encephalopathy who were evaluated with diffusion-weighted imaging (DWI) and proton MR spectroscopy (MRS) as well as conventional MR. As in conventional MR, DWI and proton MRS revealed a predominance of abnormalities in the parieto-occipital lobes and underlying white matter including the splenium of the corpus callosum. In the acute phase of the disease, lesions on DWI showed restricted water diffusion and on DWI the characteristic lesions seemed to be more readily discernible than on conventional MRI. In the chronic phase, DWI demonstrated increased water diffusion in the affected areas showing atrophy on conventional MRI. Proton MRS revealed an increased lactate-lipid peak and a decreased NAA peak in the involved areas. DWI and proton MRS findings appear helpful in evaluating the extent and the presence of neuronal damage early in the course of neonatal hypoglycaemic encephalopathy.

Brain Diseases, Metabolic↗
PubMed2005

Visibility of the origin and proximal course of coronary arteries on non-ECG-gated heart CT in patients with congenital heart disease.

BACKGROUND: There is little information on the ability of non-ECG-gated cardiac CT to demonstrate the coronary arteries of children. OBJECTIVE: To evaluate the visibility of the origin and proximal course of coronary arteries on non-ECG-gated cardiac CT, in which the coronary artery was not of primary diagnostic concern, in children with congenital heart disease. MATERIALS AND METHODS: From December 2002 to March 2004, 126 cardiac CT examinations from 104 children (median age 11 months; age range 1 day to 15 years) were evaluated. All patients had ventriculo-arterial concordance and no malformations of the great arteries; those with coronary artery anomalies were excluded. Contrast-enhanced 16-slice spiral CT was performed without ECG-gating and multiplanar images for coronary arteries were obtained. The visibility of coronary artery origins was graded on a three-point scale, while nine segments of the arteries were graded on a four-point scale. CT images in which it was possible to trace the coronary arteries were considered diagnostic. The visibility of each whole coronary artery and the origins and proximal four segments of coronary arteries were calculated. The visibility of coronary arteries was also correlated with patient age. RESULTS: The percentage of CT images of diagnostic quality was 49.3% for the whole coronary artery and 81.7% for the origins and proximal four segments. There was a significant positive correlation between the visibility of coronary arteries and age. CONCLUSIONS: Non-ECG-gated cardiac CT, in which the coronary artery is not of primary diagnostic concern, is frequently able to visualize the origin and proximal course of coronary arteries and may be helpful in detecting coronary artery anomalies in children with congenital heart disease.

Adolescent↗
PubMed2005

Whole-body MRI of paediatric malignant tumours: comparison with conventional oncological imaging methods.

PURPOSE: To evaluate the usefulness of whole-body (WB) MRI for detecting metastases from paediatric malignant tumours in comparison with conventional oncological imaging methods. MATERIALS AND METHODS: Using a 1.5-T system, a coronal short tau inversion recovery (STIR) sequence was obtained in all patients. In addition, sagittal fat-suppressed T2-weighted, sagittal STIR, or coronal fat-suppressed pre-contrast and post-contrast T1-weighted sequences were performed. Patients who underwent WB MRI and conventional oncological imaging within 15 days were enrolled in the study. In total, 58 bone scintigraphies, 26 iodine-123 (123I) meta-iodo-benzylguanidine (MIBG) scintigraphies, and 48 CT scans were available for comparison in 36 patients (median age 3.5 years; 21 boys, 15 girls) who underwent 82 WB MRI examinations. Skeletal and extraskeletal metastases were evaluated for a variety of tumour types. RESULTS: Concordance rate of WB MRI between two readers was 74%. In detecting metastases, WB MRI had higher sensitivity (99%) and PPV (94%) than bone scintigraphy (26 and 76%, respectively). In detecting skeletal metastases, WB MRI revealed higher sensitivity (100%) than 123I-MIBG scintigraphy (25%) and CT (10%). In contrast, WB MRI showed lower PPV in detecting skeletal and extraskeletal metastases (8 and 57%, respectively) than 123I-MIBG scintigraphy (100%), and lower sensitivity (60%) in detecting extraskeletal metastases than CT (100%). In 2 of 11 untreated patients, tumour staging was upgraded from stage 3 to 4 according to WB MRI findings. In 3 patients, WB MRI revealed early treatment responses (<1 year) of skeletal metastases. CONCLUSIONS: WB MRI can substitute for bone scintigraphy in detecting skeletal metastases of paediatric malignant tumours, and it is useful in evaluating initial tumour staging and early treatment responses. However, it still has only a complementary role in detecting extraskeletal metastases.

3-Iodobenzylguanidine↗
PubMed2003

Congenital intrahepatic arterioportal and portosystemic venous fistulae with jejunal arteriovenous malformation depicted on multislice spiral CT.

We report a symptomatic infant with very rare congenital arterioportal and portosystemic venous fistulae in the liver. Multislice CT after partial transcatheter embolisation revealed not only the complicated vascular architecture of the lesion, but also an incidental jejunal arteriovenous malformation which explained the patient's melena. The patient underwent ligation of the hepatic artery and resection of the jejunal arteriovenous malformation. Postoperative multislice CT clearly demonstrated the success of the treatment.

Arteriovenous Fistula↗
PubMed2003

Post-contrast FLAIR MR imaging of the brain in children: normal and abnormal intracranial enhancement.

OBJECTIVE: To describe the normally enhancing intracranial structures on fluid-attenuated inversion recovery (FLAIR) MRI and evaluate the usefulness of postcontrast FLAIR images of the brain in the assessment of enhancing lesions by comparing postcontrast FLAIR imaging with postcontrast T1-weighted (T1-W) imaging in children. MATERIALS AND METHODS: In 218 children, 249 pre- and postcontrast FLAIR MRI examinations of the brain were obtained consecutively between August 2001 and April 2002. The normally enhancing intracranial structures on FLAIR imaging were assessed in 77 MRI studies of 74 children who showed normal intracranial imaging findings. In 86 MRI studies in 68 children who showed enhancing intracranial lesions, lesion conspicuity on postcontrast FLAIR imaging was compared with that on postcontrast T1-W imaging for all lesions ( n=107), intra-axial lesions ( n=40), or extra-axial lesions ( n=67). RESULTS: The normally enhancing intracranial structures on FLAIR MRI were the choroid plexus (99%, 76/77), pituitary stalk (84%, 65/77), pineal gland (71%, 55/77), dural sinuses (26%, 20/77), and cortical veins (9%, 7/77). Of all the enhancing lesions, lesion conspicuousness on postcontrast FLAIR imaging was better than postcontrast T1-weighted imaging in 42, equal in 28, and worse in 37. Of 40 intra-axial lesions, lesion conspicuousness on postcontrast FLAIR imaging was better in 6, equal in 10, and worse in 24. Of 67 extra-axial lesions, lesion conspicuity on postcontrast FLAIR imaging was better in 36, equal in 18, and worse in 13. Conspicuousness of extra-axial lesions was significantly better than that of intra-axial lesions on postcontrast FLAIR imaging ( P<0.001). CONCLUSIONS: The choroid plexus, pituitary stalk, pineal gland, dural sinuses, and cortical veins show normal enhancement on postcontrast FLAIR MRI in children, and postcontrast FLAIR imaging appears better than postcontrast T1-W imaging in the assessment of extra-axial enhancing lesions in children.

Adolescent↗
PubMed2003

Intra-abdominal desmoplastic small round-cell tumour: multiphase CT findings in two children.

We report the multiphase CT findings of intra-abdominal desmoplastic small round-cell tumour (DSRCT) in two children. CT showed a huge heterogeneous intraperitoneal mass with or without direct invasion into solid organs such as liver or kidney, extensive intraperitoneal seeding, intratumoural calcification, ascites, and lymphadenopathy. DSRCT should be included in the differential diagnosis of malignant intraperitoneal neoplasm in children. Multiphase CT may be helpful in delineating tumour extent, vascularity and direct invasion into adjacent organs.

Abdominal Neoplasms↗
PubMed2003

MR imaging of reperfused myocardial infarction: comparison of necrosis-specific and intravascular contrast agents in a cat model.

PURPOSE: To compare T2-weighted and Gadomer-17- and bis-gadolinium mesoporphyrins-enhanced magnetic resonance (MR) images for distinguishing reversibly from irreversibly damaged myocardium in a cat model of reperfused myocardial infarction. MATERIALS AND METHODS: Twelve cats underwent 90 minutes of occlusion and 90 minutes of reperfusion of the left anterior descending coronary artery. After baseline T1- and T2-weighted MR images were obtained, Gadomer-17-enhanced and bis-gadolinium mesoporphyrins-enhanced T1-weighted images were sequentially obtained for 6 hours and 2 hours, respectively. After MR imaging, all cats were sacrificed for 2,3,5-triphenyltetrazolium chloride (TTC) histochemical tissue staining. Areas of abnormal signal intensity on T2-weighted and Gadomer-17-enhanced and bis-gadolinium mesoporphyrins-enhanced T1-weighted MR images were compared with the areas of infarction seen at TTC histochemical staining by using repeated-measures two-way analysis of variance, linear regression analysis, and Bland-Altman analysis. RESULTS: Mean areas of abnormally high signal intensity on T2-weighted and Gadomer-17-enhanced T1-weighted MR images (43.9% of the left ventricular surface area +/- 11.9 [SD] and 37.7% +/- 10.1, respectively) were significantly larger than the mean area of myocardial infarction at TTC staining (25.7% +/- 12.5) (P <.001). However, there was excellent correlation between the size of an enhancing area on bis-gadolinium mesoporphyrins-enhanced T1-weighted MR images and that of myocardial infarction at TTC staining (r = 0.916, P <.001). CONCLUSION: bis-Gadolinium mesoporphyrins-enhanced T1-weighted MR images accurately reflect the area of infarction, whereas the size of infarction is overestimated on T2-weighted and Gadomer-17-enhanced T1-weighted MR images, which seem to depict the periinfarct area as well as the infarct area.

Analysis of Variance↗
PubMed2003

Transcatheter arterial embolization of pulmonary sequestration in neonates: long-term follow-up results.

The purposes of this study are to describe experience with the safety and long-term efficacy of transcatheter arterial embolization (TAE) of pulmonary sequestration in neonates and to introduce a new technique of embolization by an umbilical-artery route. TAE was performed in five neonates, via the femoral artery in one and the umbilical artery in four. Complete regression was achieved in four cases and partial regression (>90%) was obtained in one. TAE is a safe and effective alternative therapeutic modality for the treatment of pulmonary sequestration. The umbilical artery represents a preferable route for performing embolization in neonates.

Bronchopulmonary Sequestration↗