Microvascular ultrasound (US) techniques are advanced Doppler techniques that provide high sensitivity and spatial resolution for detailed visualization of low-flow vessels. Microvascular US imaging can be applied to breast lesion evaluation with or without US contrast agents. Microvascular US imaging without a contrast agent uses a sophisticated wall filtering system to selectively obtain low-flow Doppler signals from overlapped artifacts. Microvascular US imaging with secondgeneration contrast agents amplifies flow signals and makes them last longer, which facilitates hemodynamic evaluation of breast lesions. In this review article, we will introduce various microvascular US techniques, explain their clinical applications in breast cancer diagnosis and radiologic-histopathologic correlation, and provide a summary of a recent radiogenomic study using microvascular US.

Microvascular ultrasound (US) techniques are advanced Doppler techniques that provide high sensitivity and spatial resolution for detailed visualization of low-flow vessels. Microvascular US imaging can be applied to breast lesion evaluation with or without US contrast agents. Microvascular US imaging without a contrast agent uses a sophisticated wall filtering system to selectively obtain low-flow Doppler signals from overlapped artifacts. Microvascular US imaging with secondgeneration contrast agents amplifies flow signals and makes them last longer, which facilitates hemodynamic evaluation of breast lesions. In this review article, we will introduce various microvascular US techniques, explain their clinical applications in breast cancer diagnosis and radiologic-histopathologic correlation, and provide a summary of a recent radiogenomic study using microvascular US.

PURPOSE: Venous angioma (VA) is the most common congenital abnormality of the intracranial vasculature. This study aimed to investigate the relationship between VA and epilepsy and to identify the characteristics of children with VA and epilepsy. METHODS: The records of all patients aged less than 18 years who underwent brain magnetic resonance imaging (MRI) at Pusan National University Hospital were retrospectively reviewed. Patients with isolated VA and patients with normal MRI were compared in terms of the prevalence of epilepsy. RESULTS: In total, 2,385 pediatric patients who underwent brain MRI were enrolled. Isolated VA was identified in 26 patients (VA group). Among the patients with normal MRI findings, 225 age- and sex-matched patients to the VA-group were assigned to the control group. Nine patients in the VA group (9 of 26, 34.6%) and 27 patients in the control group (26 of 225, 11.5%; P<0.001) had epilepsy. In the VA group, 20 patients (76.9%) had the VA in the cerebral hemispheres, and 6 patients (23.1%) had the VA in the brainstem and cerebellum. The latter showed a higher prevalence of epilepsy (5 of 6, 83.3%) than the former (4 of 20, 20.0%; P=0.004). Among the nine patients who had epilepsy with VA, patients whose VA involved the brainstem and cerebellum showed a significantly higher frequency of abnormal Electroencephalographic findings than patients whose VA involved the cerebral hemispheres (P=0.016). CONCLUSION: VA, especially in the brainstem and cerebellum, might be associated with epilepsy.
Brain ; Brain Stem ; Busan ; Central Nervous System Venous Angioma ; Cerebellum ; Cerebrum ; Child* ; Congenital Abnormalities ; Epilepsy* ; Hemangioma* ; Humans ; Magnetic Resonance Imaging ; Prevalence ; Retrospective Studies

Background/Aims: Low-level viremia (LLV) after nucleos(t)ide analog treatment was presented as a possible cause of hepatocellular carcinoma (HCC) in patients with chronic hepatitis B (CHB). However, detailed information on patients’ adherence in the real world was lacking. This study aimed to evaluate the effects of LLV on HCC development, mortality, and cirrhotic complications among patients according to their adherence to entecavir (ETV) treatment. Methods: We performed a retrospective observational analysis of data from 894 consecutive adult patients with treatment-naïve CHB undergoing ETV treatment. LLV was defined according to either persistent or intermittent episodes of <2,000 IU/mL detectable hepatitis B virus DNA during the follow-up period. Good adherence to medication was defined as a cumulative adherence ≥90% per study period. Results: Without considering adherence in the entire cohort (n=894), multivariate analysis of the HCC incidence showed that LLV was an independent prognostic factor in addition to other traditional risk factors in the entire cohort (P=0.031). Good adherence group comprised 617 patients (69.0%). No significant difference was found between maintained virologic response and LLV groups in terms of the incidence of liver-related death or transplantation, HCC, and hepatic decompensation in good adherence group, according to multivariate analyses. Conclusions In patients with treatment-naïve CHB and good adherence to ETV treatment in the real world, LLV during treatment is not a predictive factor for HCC and cirrhotic complications. It may be unnecessary to adjust their antiviral agent for patients with good adherence who experience LLV during ETV treatment.

BACKGROUND/AIMS: The prevalence of occult HBV infection (OBI) in patients with chronic hepatitis C (CHC) in Korea has not been reported. Additionally, it is unclear whether OBI influences treatment outcome in CHC patients. We investigated the prevalence of OBI and its impact on treatment outcome in patients with CHC. METHODS: Seventy-six patients with CHC were enrolled and treated with pegylated or conventional interferon and ribavirin. Hepatitis B virus (HBV) DNA was detected by nested polymerase chain reaction. RESULTS: Among the 68 patients who completed treatment and follow-up, HBV DNA was detected in serum from nine (13.2%) patients, liver tissue from 10 (14.7%), and serum or liver tissue from 15 (22.1%). OBI was diagnosed in nine (12.7%) control subjects. No difference in the prevalence of OBI between patients with CHC and controls was observed (13.2 vs. 12.0%; p = 0.92). No significant differences in age, sex, genotype 1 frequency, amount of hepatitis C virus RNA, anti-hepatitis B surface antigen/anti-hepatitis B core-IgG seropositivity, staging, or histology grading were observed in patients with or without HBV DNA. Sustained virological response was achieved in 73.3% of patients with OBI and 83.0% without OBI (p = 0.46). CONCLUSIONS: These results demonstrate that a significant proportion of patients with CHC have occult HBV infection and that OBI does not affect treatment outcome in patients with CHC.
DNA ; Follow-Up Studies ; Genotype ; Hepacivirus ; Hepatitis B virus ; Hepatitis C, Chronic ; Hepatitis, Chronic ; Humans ; Interferons ; Korea ; Liver ; Prevalence ; Ribavirin ; RNA ; Treatment Outcome

PURPOSE: To investigate the phosphorus metabolic abnormalities in skeletal muscle of patients with mitochondrial myopathy using in vivo 31P magnetic resonance spectroscopy(MRS). MATERIAL AND METHODS: Patients with mitochondrial myopathy(N=10) and normal control subjects (N=10) participated. All in vivo 31P MRS examinations were performed on 1.5T whole-body MRI/MRS system by using an image selected in vivo spectroscopy (ISIS) pulse sequence that provided a 4 X 4 X 4 cm3 volume of interest (VOI) in the right thigh muscle tissue. Peak areas for each phophorus methabolite were measured using a Marquart algorithm. RESULTS: The specific features in patients with mitochondrial myopathy were a significant increase of Pi/PCr ratio (p=0.003) and a significant decrease of ATP/PCr ratio (p=0.004) as compared with normal controls. In particular, the beta-ATP/PCr ratio between controls and patients with mitochondrial myopathy was predominantly altered. CONCLUSIONS: In vivo 31P MRS may be a useful modality in the clinical evaluation of patients with mitochondrial myopathy based on ATP/PCr and Pi/PCr ratios in skeletal muscle tissue and provides a valuable information in further understanding disorders of muscle metabolism.
Humans ; Magnetic Resonance Spectroscopy* ; Metabolism ; Mitochondrial Myopathies* ; Muscle, Skeletal ; Phosphorus ; Spectrum Analysis ; Thigh

PURPOSE: This study investigated the prevalence and risk factors associated with vitamin D deficiency in children. METHODS: We analyzed the medical records of 330 patients from the age of 6 to 12, who visited the endocrinology clinic of the Department of Pediatrics at Pusan National University Hospital, from September, 2013 to May, 2014. According to their serum 25-hydroxyvitamin D (25(OH)D) levels, the patients were grouped into either the deficiency group (25(OH)D<20 ng/mL), or the sufficiency group (25(OH)D≥20 ng/mL). The differences between the 2 groups were compared. RESULTS: There were 195 patients (59.1%) who had vitamin D deficiency. Their mean serum 25(OH)D level was 14.86±3.20 ng/mL. The differences in sex, age, and pubertal status between the 2 groups were not statistically significant. Weight standard deviation score (SDS), and body mass index SDS, were significantly higher in the vitamin D deficiency group (P=0.002 for each), compared to the sufficiency group. Compared with Autumn, both Spring (odds ratio [OR], 9.7; 95% confidence interval [CI], 4.3–22.0), and Winter (OR, 5.9; 95% CI, 3.5–10.0), were risk factors for vitamin D deficiency. In multiple logistic regression analysis, only seasonal differences have been confirmed to have an effect on vitamin D deficiency. CONCLUSION: Vitamin D deficiency in children aged 6 to 12 years is very common. Spring and Winter are the most important risk factors for vitamin D deficiency. We suggest that it is necessary to supplement the guideline for the vitamin D intake according to our situation.
Body Mass Index ; Busan* ; Child* ; Endocrinology ; Humans ; Logistic Models ; Medical Records ; Pediatrics ; Prevalence ; Risk Factors ; Seasons ; Vitamin D Deficiency* ; Vitamin D* ; Vitamins*

PURPOSE: This study investigated the prevalence and risk factors associated with vitamin D deficiency in children. METHODS: We analyzed the medical records of 330 patients from the age of 6 to 12, who visited the endocrinology clinic of the Department of Pediatrics at Pusan National University Hospital, from September, 2013 to May, 2014. According to their serum 25-hydroxyvitamin D (25(OH)D) levels, the patients were grouped into either the deficiency group (25(OH)D<20 ng/mL), or the sufficiency group (25(OH)D≥20 ng/mL). The differences between the 2 groups were compared. RESULTS: There were 195 patients (59.1%) who had vitamin D deficiency. Their mean serum 25(OH)D level was 14.86±3.20 ng/mL. The differences in sex, age, and pubertal status between the 2 groups were not statistically significant. Weight standard deviation score (SDS), and body mass index SDS, were significantly higher in the vitamin D deficiency group (P=0.002 for each), compared to the sufficiency group. Compared with Autumn, both Spring (odds ratio [OR], 9.7; 95% confidence interval [CI], 4.3–22.0), and Winter (OR, 5.9; 95% CI, 3.5–10.0), were risk factors for vitamin D deficiency. In multiple logistic regression analysis, only seasonal differences have been confirmed to have an effect on vitamin D deficiency. CONCLUSION: Vitamin D deficiency in children aged 6 to 12 years is very common. Spring and Winter are the most important risk factors for vitamin D deficiency. We suggest that it is necessary to supplement the guideline for the vitamin D intake according to our situation.
Body Mass Index ; Busan* ; Child* ; Endocrinology ; Humans ; Logistic Models ; Medical Records ; Pediatrics ; Prevalence ; Risk Factors ; Seasons ; Vitamin D Deficiency* ; Vitamin D* ; Vitamins*