Renal Branch Artery Stenosis: A Diagnostic Challenge? A Case Report With Review of the Literature.

Renovascular hypertension is a common cause of pediatric hypertension. In the fraction of cases that are unrelated to syndromes such as neurofibromatosis, patients with a solitary stenosis on a branch of the renal artery are common and can be diagnostically challenging. Imaging techniques that perform well in the diagnosis of main renal artery stenosis may fall short when it comes to branch artery stenosis. We report 2 cases that illustrate these difficulties and show that a branch artery stenosis may be overlooked even by the gold standard method, renal angiography.

Ovarian morphology and function during growth hormone therapy of short girls born small for gestational age.

OBJECTIVE: To study the effect of growth hormone (GH) treatment on ovarian and uterine morphology and function in short, prepubertal small-for-gestational-age (SGA) girls. DESIGN: A multinational, randomized controlled trial on safety and efficacy of GH therapy in short, prepubertal children born SGA. SETTING: Not applicable. PATIENT(S): A subgroup of 18 Danish girls born SGA included in North European SGA Study (NESGAS). INTERVENTION(S): One year of GH treatment (67 µg/kg/day) followed by 2 years of randomized GH treatment (67 µg/kg/day, 35 µg/kg/day, or IGF-I titrated). MAIN OUTCOME MEASURE(S): Data on anthropometrics, reproductive hormones, and ultrasonographic examination of the internal genitalia were collected during 36 months of GH treatment. RESULT(S): Uterine and ovarian volume increased significantly during 3 years of treatment (64% and 110%, respectively) but remained low within normal reference ranges. Ovarian follicles became visible in 58% after 1 year compared with 28% before GH therapy. Anti-Müllerian hormone increased significantly during the 3 years of GH therapy but remained within the normal range. Precocious puberty was observed in one girl; another girl developed multicystic ovaries. CONCLUSION(S): GH treatment was associated with statistically significant growth of the internal genitalia, but remained within the normal range. As altered pubertal development and ovarian morphology were found in 2 of 18 girls, monitoring of puberty and ovarian function during GH therapy in SGA girls is prudent. Altogether, the findings are reassuring. However, long-term effects of GH treatment on adult reproductive function remain unknown. CLINICAL TRIAL REGISTRATION NUMBER: EudraCT 2005-001507-19.

(1)H MRS assessment of hepatic steatosis in overweight children and adolescents: comparison between 3T and open 1T MR-systems.

PURPOSE: In recent years, proton magnetic resonance spectroscopy (MRS) has emerged as a non-invasive technique for measurement of fat content in the liver. The technique is often applied for overweight and obese patients. However, excessively obese patients cannot be examined in most conventional magnetic resonance systems due to limited space. The purpose of this study was to examine the ability of open 1T system to monitor liver fat with proton MRS and to compare hepatic fat fractions (HFFs) obtained using an open 1T system with assessment with 3T proton MRS. METHODS: The study included 23 children and adolescents up to 20 years of age with a body mass index above the 97th percentile according to age and gender. Proton MRS for each patient was performed in both 1T and 3T using point resolved spectroscopy sequence in a single volume positioned in the right liver lobe. RESULTS: Average T2 relaxation times obtained for an open 1T system (55 ± 7 ms for water and 85 ± 11 ms for fat) were higher than average T2 relaxation times obtained for a 3T system (31 ± 4 ms for water and 66 ± 10 ms for fat). HFFs measured using an open 1T system showed strong correlation with HFFs measured using a 3T system (r = 0.99, P < 0.0001). CONCLUSIONS: Proton MRS measurements of HFF with an open 1T system are feasible. Open 1T system may reliably replace 3T magnetic resonance system for the assessment of liver fat.

Development of obesity and polycystic ovary syndrome in adolescents.

Obesity in adolescents is prevalent worldwide. Polycystic ovary syndrome (PCOS) is often associated with obesity in women, and it has serious metabolic and reproductive health implications. Although PCOS does not become clinically visible until early adolescence, its origins are likely much earlier. Therefore, we reviewed the recent literature regarding the mechanisms linking the development of PCOS and obesity in adolescent girls. We found that excess abdominal adipose tissue (AT) initiates metabolic and endocrine aberrations that are central in the progression of PCOS. As an example, abdominal AT impairs insulin action, which interacts with the progression of hyperandrogenism. In addition, excessive androgen levels lead to impaired glucose uptake, which also contributes to insulin resistance, which again increases the deposition of visceral fat. The body composition is influenced by testosterone, which decreases subcutaneous fat lipolysis and influences adipocyte distribution. These mechanisms may explain why PCOS girls have an increased visceral adipose mass independent of body mass index. Therefore, first-line treatment in adolescent PCOS is often lifestyle intervention to prevent the damaging effects of obesity. Pharmacological treatment of adolescent PCOS is not standardized because the long-term effects in adolescents have not yet been evaluated; therefore, drugs should be prescribed cautiously. Although the complex metabolic interrelationships between obesity and PCOS have yet to be fully understood, the co-occurrence of these conditions in adolescent girls tends to increase the severity of the negative health consequences of each condition.

MR spectroscopy of liver in overweight children and adolescents: investigation of ¹H T2 relaxation times at 3T.

OBJECTIVE: The objective was to investigate T(2) relaxation values and to optimize hepatic fat quantification using proton MR spectroscopy ((1)H MRS) at 3T in overweight and obese children and adolescents. SUBJECTS: The study included 123 consecutive children and adolescents with a body mass index above the 97th percentile according to age and sex. (1)H MR spectroscopy was performed at 3.0 T using point resolved spectroscopy sequence with series TE. T(2) relaxation values and hepatic fat content corrected for the T(2) relaxation effects were calculated. RESULTS: T(2) values for water ranged from 22 ms to 42 ms (mean value 28 ms) and T(2) values for fat ranged from 36 ms to 99 ms (mean value 64 ms). Poor correlation was observed: (1) between T(2) relaxation times of fat and T(2) relaxation times of water (correlation coefficient r=0.038, P=0.79); (2) between T(2) relaxation times of fat and fat content (r=0.057, P=0.69); (3) between T(2) relaxation times of water and fat content (r=0.160, P=0.26). Correlation between fat peak content and the T(2) corrected fat content decreased with increasing echo time TE: r=0.97 for TE=45, r=0.93 for TE=75, r=0.89 for TE=105, P<0.0001. CONCLUSION: (1)H MRS at 3T is an effective technique for measuring hepatic fat content in overweight and obese children and adolescents. It is necessary to measure T(2) relaxation values and to correct the spectra for the T(2) relaxation effects in order to obtain an accurate estimate of the hepatic fat content.