Socio-economic factors and medical conditions affecting regular stomach cancer screening in Korea: a retrospective longitudinal study using national public health data for 11 years

OBJECTIVE

This study aimed to explore socio-economic factors and medical conditions that affect regular stomach cancer (SC) screening among Korean adults.

STUDY DESIGN

This was a retrospective observational study.

METHODS

Study subjects were 5545 adults aged ≥40 years who participated in the 2007-2012 Korean National Health and Nutrition Examination Survey and were followed up to year 2017 based on data linking to the Korean National Health Insurance Service and Korean Health Insurance Review and Assessment. Socio-economic factors included sex, age, residential area, education, occupation, marital status, disability, public and private health insurance, service through local public health organizations, history of cancer except for SC, and family history of SC. Medical factors included six gastric lesions with the possibility of facilitating SC screening, including benign gastric neoplasm, chronic atrophic gastritis, gastric polyp, Helicobacter pylori infection, intestinal metaplasia, and peptic ulcers. The outcome was adherence to SC screening, which was divided into non-adherence, irregular adherence, and regular adherence.

RESULTS

After adjusting for the effects of socio-economic factors, multivariate ordinal logistic regression revealed that participants with a history of four types of gastric lesions were more likely to regularly participate in SC screening: chronic atrophic gastritis (odds ratio [OR] 1.567; 95% confidence interval [CI] = 1.276-1.923), gastric polyps (OR 1.565; 95% CI = 1.223-2.003), H. pylori infection (OR 1.637; 95% CI = 1.338-2.003), and peptic ulcer (OR 2.226; 95% CI 1.750-2.831).

CONCLUSIONS

To improve participation in SC screening, it is necessary to implement personalized strategies for individuals at risk for gastric cancer in addition to population-based strategies for vulnerable groups.

Diagnostic performance of synthetic relaxometry for predicting neurodevelopmental outcomes in premature infants: a feasibility study

OBJECTIVES

To investigate the predictability of synthetic relaxometry for neurodevelopmental outcomes in premature infants and to evaluate whether a combination of relaxation times with clinical variables or qualitative MRI abnormalities improves the predictive performance.

METHODS

This retrospective study included 33 premature infants scanned with synthetic MRI near or at term equivalent age. Based on neurodevelopmental assessments at 18-24 months of corrected age, infants were classified into two groups (no/mild disability [n = 23] vs. moderate/severe disability [n = 10]). Clinical and MRI characteristics associated with moderate/severe disability were explored, and combined models incorporating independent predictors were established. Ultimately, the predictability of relaxation times, clinical variables, MRI findings, and a combination of the two were evaluated and compared. The models were internally validated using bootstrap resampling.

RESULTS

Prolonged T1-frontal/parietal and T2-parietal periventricular white matter (PVWM), moderate-to-severe white matter abnormality, and bronchopulmonary dysplasia were significantly associated with moderate/severe disability. The overall predictive performance of each T1-frontal/-parietal PVWM model was comparable to that of individual MRI finding and clinical models (AUC = 0.71 and 0.76 vs. 0.73 vs. 0.83, respectively; p > 0.27). The combination of clinical variables and T1-parietal PVWM achieved an AUC of 0.94, sensitivity of 90%, and specificity of 91.3%, outperforming the clinical model alone (p = 0.049). The combination of MRI finding and T1-frontal PVWM yielded AUC of 0.86, marginally outperforming the MRI finding model (p = 0.09). Bootstrap resampling showed that the models were valid.

CONCLUSIONS

It is feasible to predict adverse outcomes in premature infants by using early synthetic relaxometry. Combining relaxation time with clinical variables or MRI finding improved prediction.

CLINICAL RELEVANCE STATEMENT

Synthetic relaxometry performed during the neonatal period may serve as a biomarker for predicting adverse neurodevelopmental outcomes in premature infants.

KEY POINTS

• Synthetic relaxometry based on T1 relaxation time of parietal periventricular white matter showed acceptable performance in predicting adverse outcome with an AUC of 0.76 and an accuracy of 78.8%. • The combination of relaxation time with clinical variables and/or structural MRI abnormalities improved predictive performance of adverse outcomes. • Synthetic relaxometry performed during the neonatal period helps predict adverse neurodevelopmental outcome in premature infants.

Prenatal Diagnosis of Fetal Obstructed Hemivagina and Ipsilateral Renal Agenesis (OHVIRA) Syndrome

Background: Obstructed hemivagina and ipsilateral renal agenesis (OHVIRA) syndrome, also known as Herlyn-Werner-Wunderlich syndrome, is a rare syndrome characterized by the triad of uterus didelphys, obstructed hemivagina, and ipsilateral renal agenesis. Most cases of OHVIRA have been reported in adolescents or adults. Gartner duct cysts, including those manifesting as vaginal wall cysts, are also rare. Fetal OHVIRA syndrome and Gartner duct cysts are difficult to diagnose. Case Presentation: Here, the authors report a case of combined OHVIRA and Gartner duct cyst diagnosed prenatally by ultrasonography, along with a brief review of the relevant published reports. A 30-year-old nulliparous female was referred to our institution at 32 weeks’ gestation for fetal right kidney agenesis. Detailed ultrasonographic examinations using 2D, 3D, and Doppler ultrasounds revealed hydrocolpometra, and uterus didelphys, with a normal anus and right kidney agenesis. Conclusions: When encountering female fetuses with ipsilateral renal agenesis or vaginal cysts, clinicians should be aware of OHVIRA syndrome and Gartner duct cysts and perform systematic ultrasonographic examinations for other genitourinary anomalies.

Adaptation of Deep Learning Image Reconstruction for Pediatric Head CT: A Focus on the Image Quality

Purpose

To assess the effect of deep learning image reconstruction (DLIR) for head CT in pediatric patients.

Materials and Methods

We collected 126 pediatric head CT images, which were reconstructed using filtered back projection, iterative reconstruction using adaptive statistical iterative reconstruction (ASiR)-V, and all three levels of DLIR (TrueFidelity; GE Healthcare). Each image set group was divided into four subgroups according to the patients' ages. Clinical and dose-related data were reviewed. Quantitative parameters, including the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR), and qualitative parameters, including noise, gray matter-white matter (GM-WM) differentiation, sharpness, artifact, acceptability, and unfamiliar texture change were evaluated and compared.

Results

The SNR and CNR of each level in each age group increased among strength levels of DLIR. High-level DLIR showed a significantly improved SNR and CNR (p < 0.05). Sequential reduction of noise, improvement of GM-WM differentiation, and improvement of sharpness was noted among strength levels of DLIR. Those of high-level DLIR showed a similar value as that with ASiR-V. Artifact and acceptability did not show a significant difference among the adapted levels of DLIR.

Conclusion

Adaptation of high-level DLIR for the pediatric head CT can significantly reduce image noise. Modification is needed while processing artifacts.

Left ventricular rehabilitation in an infant with transposition of the great arteries, intact ventricular septum, pulmonary stenosis, and small left ventricle

We report a case of successful biventricular repair after left ventricular rehabilitation in an infant with transposition of the great arteries with an intact ventricular septum, pulmonary stenosis, a large atrial septal defect, and a borderline-small left ventricle (mitral annulus Z-score: -3.6). This baby presented to us at two months of age after having a modified Blalock-Taussig shunt from another hospital. We restricted the atrial septal defect under cardiopulmonary bypass. Ten weeks later, the mitral annulus Z-score increased to - 1.5, and the transpulmonary peak pressure gradient to 87 mmHg. Subsequently, we performed the aortic root translocation. Currently, he is a four-year-old active boy.

Feasibility of Pediatric Low-Dose Facial CT Reconstructed with Filtered Back Projection Using Adequate Kernels

Purpose

Materials and Methods

Results

Conclusion

Intestinal Ganglioneuromatosis in a Pediatric Patient Presenting as Perforation: A Case Report and Literature Review

Intestinal ganglioneuromatosis is an extremely rare condition, particularly in pediatric patients, and the imaging features of the disease have been rarely reported before. Herein, we present a pediatric case of intestinal ganglioneuromatosis involving the transverse colon and splenic flexure with bowel perforation, which is a rare initial manifestation of the disease.

Prevalence of Incidentally Detected Spondylolysis in Children

Purpose

To assess the prevalence of incidentally detected lumbar spondylolysis in children.

Materials and Methods

We retrospectively reviewed the data of 809 patients under the age of 11 years (mean age, 7.0 ± 2.7 years; boys:girls = 479:330) who underwent abdominal and pelvic CT between March 2014 and December 2018. We recorded the presence, level, and laterality (unilateral or bilateral) of spondylolysis. Patients were divided into two groups based on the presence of spondylolysis: the spondylolysis (SP) and non-SP groups.

Results

In total, 21 cases of spondylolysis were detected in 20 patients (20/809, 2.5%). The mean age of the SP group was higher than that of the non-SP group (7.8 ± 1.8 vs. 6.9 ± 2.7 years, p > 0.05). The prevalence of spondylolysis in boys was higher than that in girls (15/479 [3.1%] vs. 5/330 [1.5%], p > 0.05). The prevalence of spondylolysis in school-age children (6–10 year olds) was higher than that in preschool-age children (0–5 year olds) (17/538 [3.2%] vs. 3/271 [1.1%], p > 0.05). L5 was the most common level of spondylolysis (76.2%); one 8-year-old boy had twolevel spondylolysis. One case of isthmic spondylolisthesis was detected in a 10-year-old boy (1/809, 0.1%). There were 11 unilateral spondylolysis cases (11/21, 52.4%).

Conclusion

In our study, the prevalence of spondylolysis in children under the age of 11 was 2.5%. The prevalence was higher in boys than in girls and in school-age than in preschool-age children, despite the lack of any statistically significant differences.

Clinical adaptation of synthetic MRI-based whole brain volume segmentation in children at 3 T: comparison with modified SPM segmentation methods

PURPOSE

To validate the use of synthetic magnetic resonance imaging (SyMRI) volumetry by comparing with child-optimized SPM 12 volumetry in 3 T pediatric neuroimaging.

METHODS

In total, 106 children aged 4.7-18.7 years who underwent both synthetic and 3D T1-weighted imaging and had no abnormal imaging/neurologic findings were included for the SyMRI vs. SPM T1-only segmentation (SPM T1). Forty of the 106 children who underwent an additional 3D T2-weighted imaging were included for the SyMRI vs. SPM multispectral segmentation (SPM multi). SPM segmentation using an age-appropriate atlas and inverse-transforming template-space intracranial mask was compared with SyMRI segmentation. Volume differences between SyMRI and SPM T1 were plotted against age to evaluate the influence of age on volume difference.

RESULTS

Measurements derived from SyMRI and two SPM methods showed excellent agreements and strong correlations except for the CSF volume (CSFV) (intraclass correlation coefficients = 0.87-0.98; r = 0.78-0.96; relative volume difference other than CSFV = 6.8-18.5% [SyMRI vs. SPM T1] and 11.3-22.7% [SyMRI vs. SPM multi]). Dice coefficients of all brain tissues (except CSF) were in the range 0.78-0.91. The Bland-Altman plot and age-related volume difference change suggested that the volume differences between the two methods were influenced by the volume of each brain tissue and subject's age (p < 0.05).

CONCLUSION

SyMRI and SPM segmentation results were consistent except for CSFV, which supports routine clinical use of SyMRI-based volumetry in pediatric neuroimaging. However, caution should be taken in the interpretation of the CSF segmentation results.

Bowel Wall Thickening on Computed Tomography in Children: A Novel Method of Measurement and Its Clinical Significance

PURPOSE

The clinical implications of bowel wall thickening (BWT) on abdominal computed tomography (CT) among children are unknown. We aimed to suggest a new method for measuring BWT and determining its clinical significance in children.

METHODS

We retrospectively analyzed 423 patients with acute abdomen who underwent abdominal CT; 262 were classified into the BWT group. For this group, the pediatric radiologist described the maximal bowel wall thickness (MT), normal bowel wall thickness (mm) (NT), and their ratios for each segment of the bowel wall.

RESULTS

In the thickened bowel walls, the thickness differed significantly between the small bowel (6.83±2.14 mm; mean±standard deviation) and the colon (8.56±3.46 mm; p<0.001). The ratios of MT to NT in the small bowel (6.09±3.17) and the colon (7.58±3.70) were also significantly different (p<0.001). In the BWT group, 35 of 53 patients had positive fecal polymerase chain reaction results; 6 patients infected with viruses predominantly had BWT in the small intestine, while the terminal ileum and the colon were predominantly affected in 29 patients with bacterial infections. In the initially undiagnosed 158 patients with BWT, the symptoms improved spontaneously without progression to chronic gastrointestinal disease.

CONCLUSION

This study provides a clinical reference value for BWT in the small intestine and colon using a new method in children. The BWT on abdominal CT in children might indicate nonspecific findings that can be observed and followed up without additional evaluation, unlike in adults.

Significance of sonographically detected bladder debris in children less than 2 years old with febrile urinary tract infection

PURPOSE

To investigate the relationship between bladder debris found on renal and bladder ultrasonography (RBUS) and the first febrile urinary tract infection (UTI) episode in children under 2 years old.

METHODS

We retrospectively reviewed the data of children aged <2 years with the first febrile UTI. We recorded bladder debris on RBUS and other findings (blood test, urinalysis, and urine culture). Other RBUS findings (renal pelvis debris, renal parenchymal change, wall thickening, and renal collecting system [RCS] dilatation) were recorded. Patients were divided into the debris (D) and non-D groups.

RESULTS

Of 128 patients (boys: girls = 81:47, mean age = 5.6 ± 4.2 months), 24 (18.8%) had bladder debris. The mean C-reactive protein (CRP) levels were higher in the D group (6.1 ± 4.0 vs 4.3 ± 3.5, P = .03). Twenty-one patients in the D group (87.5%) had hematuria (odds ratio = 3.706, 95% confidence interval = 1.035-13.267, P = .04). No significant differences were seen in the urine culture results between both groups. Significant associations were seen between bladder debris and other RBUS findings such as debris in renal pelvis, renal parenchymal change, and RCS wall thickening.

CONCLUSION

Bladder debris on RBUS is a common finding in children aged <2 years during the first febrile UTI. Bladder debris was related to higher CRP levels, hematuria and sonographic findings, but not to urine culture results.

Effect of using immobilization device in fluoroscopic study in pediatric patient: Focused on radiation dose reduction in voiding cystourethrogram

Introduction

To prove objective effect of using mechanical device for immobilization of pediatric patient during voiding cystourethrogram (VCUG) compare immobilization by hand-holding.

Methods

This study included 77 patients, who underwent VCUG in our center from April to October 2017, who had a clinically suspicious urinary tract infection. Patients were classified into one of two groups based on whether examination was done before (Group A) or after (Group B) adaptation of immobilization device. Patient-related data, image quality related score and dose-related data were collected and compared between two groups.

Results

Group A included 36 patients and group B included 41. Patient related data including mean age, sex, body weight and height didn’t show significant difference between two groups (p > 0.05 for all). Among the image quality scoring, overall image quality, motion artifact, showed significant difference between two groups with improved inadequate timing and centering after adaptation of immobilization device. Dose related data showed significantly decreased shot number, mean fluoroscopic time with decreased mean dose area product (DAP) value and effective dose after adaptation of immobilization device (p < 0.05 for all).

Conclusion

Adaptation of immobilization device can improve overall image quality with decreased motion artifact and improved centering and timing with even shot number, mean fluoroscopic time with decreased mean DAP value and effective dose.

Optimal Timing of Spinal Ultrasound Evaluations for Sacral Dimples in Neonates: Earlier May Not Be Better

OBJECTIVES

A spinal ultrasound (US) evaluation during the immediate postnatal period may have limited ability in evaluating filum thickness because of the spinal cord pulsation caused by a crowded subarachnoid space and the cerebrospinal fluid deficiency during this period. This study aimed to determine the optimal timing of spinal US to evaluate sacral dimples in neonates.

METHODS

This study included 585 neonates who had a clinically suspicious sacral dimple and underwent spinal US examinations between January 2015 and August 2017. Patients were classified into 1 of 2 groups based on whether measurements of all parameters were possible (group A) or not (group B). Neonatal and maternal clinical factors, including the antenatal history and US parameters, were compared between groups.

RESULTS

Group A included 443 patients, and group B included 82. Patients in group B were significantly younger (6.2 versus 31.0 days), had a younger corrective age (38.9 versus 42.5 weeks), and had a smaller body weight (3.1 versus 4.6 kg) than those in group A (all P < .005). However, no statistically significant differences were found in other patient or maternal factors (P > .05 for all). The pulsation of the conus medullaris and nerve roots of the cauda equina (14.6% versus 100%), thickening and echogenicity of the filum terminale (2.4% versus 100%), and the presence of a normal subarachnoid space (18.3% versus 100%) were significantly more difficult to detect in group B than in group A (all P < .001).

CONCLUSIONS

For an accurate evaluation, which can reduce unnecessary confusion and costs, spinal US can be delayed until neonates grow beyond 31 days, with a corrected age of older than 42.5 weeks and body weight of greater than 4.6 kg.

Effect of low tube voltage and low iodine concentration abdominal CT on image quality and radiation dose in children: preliminary study

PURPOSE

To evaluate the image quality of a double-low protocol (low tube voltage and low iodine concentration) for abdominal CT in children.

MATERIALS AND METHODS

The double-low protocol was compared to the conventional protocol in pediatric patients weighing less than 40 kg from May 2016 to December 2016. Double-low protocol (Group A, n = 18): tube voltage, 70 kVp; and iodine concentration,: 250 mgI/mL versus Conventional protocol (Group B, n = 13): tube voltage, 80-100 kVp; and iodine concentration, 350 mgI/mL. Mean attenuation, noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were compared between the two groups. Image contrast, noise, beam-hardening artifacts, and overall image quality were subjectively scored. Reader performance for correctly differentiating two groups by visual assessment was evaluated. Radiation dose and total iodine load were recorded.

RESULTS

The mean attenuations of the portal vein and liver and the mean image noise in Group A were higher than in Group B (p = 0.04, 0.03, 0.004, respectively). The mean SNR and CNR of the main portal vein and liver were lower in Group A without any statistically significant difference. There were no statistically significant differences between the two groups in qualitative analysis (image contrast, image noise, and overall image quality) with substantial agreement between the reviewers (weighted kappa values; 0.59-0.76). Significantly diminished radiation dose and iodine load were observed in Group A compared with Group B (25.0%, 36.8% reduction; p = 0.007, 0.006, respectively).

CONCLUSION

The double-low protocol was feasible for pediatric abdominal CT and reduced both radiation dose and iodine load, while maintaining image quality.

Age-dependent reference values of the thyroid gland in pediatric population; from routine computed tomography data

PURPOSE

To evaluate age-dependent reference values for measurements of the thyroid gland in pediatric patients.

METHOD

In total 425 chest and neck computed tomography images of pediatric patients without pathology of the thyroid gland were retrospectively reviewed. Measurements of the thyroid gland were obtained in three dimensions (width, depth, length). The total volume was the sum of volumes of each lobe. Measurements were compared among the six groups according to age from 0 to 18 years.

RESULTS

There were moderate to strong positive linear correlations between age and all values (r = 0.58-0.82, all p < 0.001). The total volume of the thyroid gland showed a strong positive linear correlation with the three linear measurements of each lobe (all r > 0.7, all p < 0.001). Among these measurements, the depth of the right lobe showed the highest Pearson correlation coefficient with the total volume of the thyroid gland (r = 0.859).

CONCLUSION

The depth of right lobe could be a representative measurement of total thyroid gland volume, similar to prior findings in adults.

Adenovirus pneumonia treated with Cidofovir in an immunocompetent high school senior

Most adenovirus infections are self-limiting in immunocompetent individuals. Here, we report a case of adenovirus pneumonia in a 17-year-old immunocompetent male. He was admitted to our emergency room complaining of a febrile sense, cough, and diarrhea for four days. Crackles in the left lung and a high fever (40.7 °C) were revealed. Initial chest X-ray and computed tomography images showed consolidation in the left lung. We immediately started empirical antibiotic treatment, but his clinical symptoms and pneumonic consolidation in radiography had not improved by hospital day three. Because adenovirus was detected in his sputum using RT-PCR, he was administered Cidofovir. After 24 h of Cidofovir treatment, the symptoms and fever subsided, and the consolidation in his X-ray was significantly reduced by hospital day nine. The early administration of Cidofovir could be beneficial for the treatment of adenovirus infection in immunocompetent patients.

Antibiotics-Associated Hemorrhagic Colitis Caused by Klebsiella oxytoca: Two Case Reports

Nowadays, Klebsiella oxytoca is described as a causative organism for antibiotic-associated hemorrhagic colitis (AAHC). Here we report two cases of pediatric AAHC, from which K. oxytoca was cultured after starting amoxicillin-clavulanate or amoxicillin treatment. The patients developed severe abdominal pain and a large amount of bloody diarrhea. K. oxytoca was obtained in intestinal fluid culture of a boy through the colonoscopy. On the other hand, colonic tissue culture and intestinal fluid culture were negative of the other patient. K. oxytoca was detected in stool culture when he was admitted. These cases showed characteristic endoscopic findings of segmental hemorrhagic colitis, and both boys recovered spontaneously within 2-3 days after they stopped taking the antibiotics. Therefore, in children who develop relatively large amount of bloody diarrhea after antibiotic treatment, we should consider AAHC caused by K. oxytoca.

Image quality at synthetic brain magnetic resonance imaging in children

BACKGROUND

The clinical application of the multi-echo, multi-delay technique of synthetic magnetic resonance imaging (MRI) generates multiple sequences in a single acquisition but has mainly been used in adults.

OBJECTIVE

To evaluate the image quality of synthetic brain MR in children compared with that of conventional images.

MATERIALS AND METHODS

Twenty-nine children (median age: 6 years, range: 0-16 years) underwent synthetic and conventional imaging. Synthetic (T2-weighted, T1-weighted and fluid-attenuated inversion recovery [FLAIR]) images with settings matching those of the conventional images were generated. The overall image quality, gray/white matter differentiation, lesion conspicuity and image degradations were rated on a 5-point scale. The relative contrasts were assessed quantitatively and acquisition times for the two imaging techniques were compared.

RESULTS

Synthetic images were inferior due to more pronounced image degradations; however, there were no significant differences for T1- and T2-weighted images in children <2 years old. The quality of T1- and T2-weighted images were within the diagnostically acceptable range. FLAIR images showed greatly reduced quality. Gray/white matter differentiation was comparable or better in synthetic T1- and T2-weighted images, but poorer in FLAIR images. There was no effect on lesion conspicuity. Synthetic images had equal or greater relative contrast. Acquisition time was approximately two-thirds of that for conventional sequences.

CONCLUSION

Synthetic T1- and T2-weighted images were diagnostically acceptable, but synthetic FLAIR images were not. Lesion conspicuity and gray/white matter differentiation were comparable to conventional MRI.

Analysis of the sacroiliac joint vacuum phenomenon in paediatric patients

OBJECTIVE

To assess the incidence of the sacroiliac joint vacuum phenomenon (SIJ VP) in paediatric patients and the relationship between the presence of VP and clinical factors such as age, sex and body mass index (BMI).

METHODS

We retrospectively reviewed clinical data and imaging findings of 60 patients who underwent abdominopelvic CT (AP CT) between January and June 2015. Patients were divided into VP group and non-VP group based on the presence/absence of VP, and the groups were compared. In addition, other degenerative changes in the SIJ were recorded.

RESULTS

The SIJ VP was detected in 19 (31.6%) patients. There were no significant differences in sex distribution between VP and non-VP groups (p = 0.781). The age of the VP group was significantly higher than that of the non-VP group (p < 0.001). After adjusting the BMI for age, there was no significant association between high BMI and the presence of SIJ VP (p = 0.326). Other degenerative changes were not noted in any of the patients.

CONCLUSION

The SIJ VP is not an uncommon finding in paediatric patients. The prevalence of SIJ VP in paediatric patients is similar to its prevalence in adults. The SIJ VP is related to patient age, but not to sex or BMI in children and young adolescents. Advances in knowledge: AP CT can provide information about the SIJ, if it is required to assess the SIJ in paediatric patients.

Changes in brain magnetic resonance imaging patterns for preterm infants after introduction of a magnetic resonance-compatible incubator coil system: 5-year experience at a single institution

OBJECTIVE

To evaluate the changes in using patterns of brain magnetic resonance imaging (MRI) in preterm infants after introduction of a MR-compatible incubator coil system.

MATERIALS AND METHODS

Brain MRIs for preterm infants with the MR-compatible incubator coil from March 2010 to July 2014 (n=154, group A) were compared with MRIs prior to the introduction of the incubator coil, from March 2005 to February 2010 (n=65, group B). Clinical data, MRI findings, acquisition time, and incidence of adverse events during the study were retrospectively reviewed. For the qualitative analysis of the examinations, the presence of motion artefact, spatial resolution, and overall image quality were assessed. Signal uniformity of each sequence was evaluated for a quantitative comparison.

RESULTS

Comparing with group B, Group A was significantly younger (36+3 vs. 38+3 weeks, p<0.001), had a significantly lower body weight (2006.6 and 2390.3g respectively; p<0.001) at the time of MRI, and had shorter time interval (54.3±2.6 vs. 70.5±4.4days, p=0.002) between birth and examination. Abnormal findings were noted more frequently in group A (n=100, 65%) than in B (n=24, 37%. p=0.001) with a significantly higher incidence of diffusion restriction (n=21, 13.6% vs. n=4, 6.2%, p=0.034). Mean image acquisition time was significantly shorter in group A (21.4±4.5 vs. 25.4±5.5min, p<0.001) with significant lower adverse events during MRI (n=26, 40 vs. n=6, 3.9%, p<0.001). Group A exhibited significantly less motion artefact, better spatial resolution, and better overall image quality with decreased signal variation than group B (all p<0.001).

CONCLUSION

Application of the MR-compatible incubator for preterm brain MRI evaluation is safer and provides more timely evaluation of preterm infants with better image quality.

Early imaging findings in germ cell tumors arising from the basal ganglia

BACKGROUND

It is difficult to diagnosis early stage germ cell tumors originating in the basal ganglia, but early recognition is important for better outcome.

OBJECTIVE

To evaluate serial MR images of basal ganglia germ cell tumors, with emphasis on the features of early stage tumors.

MATERIALS AND METHODS

We retrospectively reviewed serial MR images of 15 tumors in 14 children and young adults. We categorized MR images of the tumors as follows: type I, ill-defined patchy lesions (<3 cm) without cyst; type II, small mass lesions (<3 cm) with cyst; and type III, large lesions (≥3 cm) with cyst. We also assessed temporal changes of the MR images.

RESULTS

On the initial images, 8 of 11 (73%) type I tumors progressed to types II or III, and 3 of 4 (75%) type II tumors progressed to type III. The remaining 4 tumors did not change in type. All type II tumors (5/5, 100%) that changed from type I had a few tiny cysts. Intratumoral hemorrhage was observed even in the type I tumor. Ipsilateral hemiatrophy was observed in most of the tumors (13/15, 87%) on initial MR images. As tumors grew, cystic changes, intratumoral hemorrhage, and ipsilateral hemiatrophy became more apparent.

CONCLUSION

Early stage basal ganglia germ cell tumors appear as ill-defined small patchy hyperintense lesions without cysts on T2-weighted images, are frequently associated with ipsilateral hemiatrophy, and sometimes show microhemorrhage. Tumors develop tiny cysts at a relatively early stage.

Prediction of High-grade Vesicoureteral Reflux in Children Younger Than 2 Years Using Renal Sonography

OBJECTIVES

To investigate the predictive value of renal sonography for vesicoureteral reflux (VUR) and the efficacy of renal sonography, technetium Tc 99m–labeled dimercaptosuccinic acid (DMSA) scanning, and a combination of the two for VUR screening in children younger than 2 years with a first episode of febrile urinary tract infection.

METHODS

Thirty-eight patients younger than 2 years with a first febrile urinary tract infection were included in our study, which was conducted from April through October 2014. Each kidney was considered a separate renal unit. A retrospective review of clinical information and images (renal sonography, DMSA scanning, and voiding cystourethrography) was performed.

RESULTS

Of the 14 renal units (18.4%) with VUR, 4 (28.5%) had high-grade VUR. Among single findings, dilatation of the renal collecting system, wall thickening of the renal collecting system, and DMSA scans significantly predicted VUR (P= .038, .027, and .01, respectively). Dilatation was the most common single finding (46 of 76 renal units). The sensitivity values for dilatation, wall thickening, and DMSA scans were 85.7%, 64.2%, and 50.0%, and the negative predictive values were 93.3%, 89.7%, and 87.9%.

CONCLUSIONS

The negative predictive values indicate that normal renal sonographic and DMSA findings can predict the absence of high-grade VUR. We propose that renal sonographic findings of wall thickening as well as dilatation of the renal collecting system should be considered predictive of high-grade VUR.

Ultrasonography evaluation of infants with Alagille syndrome: In comparison with biliary atresia and neonatal hepatitis

OBJECTIVE

To evaluate the ultrasonography (US) features of Alagille syndrome (ALGS), as compared with biliary atresia (BA) or neonatal hepatitis (NH).

METHODS

Our study included 23 ALGS, 75 BA and 70 NH patients. The initial US images were retrospectively reviewed for gallbladder (GB) morphology with systemic classification, GB length and luminal area, presence of triangular-cord (TC) sign and hypertrophied hepatic-artery. The presence of anomalies associated with ALGS was evaluated. The diagnostic values of each finding and their combinations were evaluated.

RESULTS

Both ALGS (57%) and BA (79%) were more frequently associated with abnormal GB shapes than NH (19%, all P<0.001). The short and small GBs were more frequently observed in ALGS and BA than in NH (all P<0.001). None in the ALGS and NH showed TC sign, while 41% in the BA did (all P<0.001). Hypertrophied hepatic-artery was noted less frequently in both ALGS (13%) and NH (14%) than in BA (83%, all P<0.001). The combination of US criteria with associated anomalies increased the positive-predictive-value for ALGS.

CONCLUSION

Abnormal shaped GB with absence of the TC sign and hypertrophied hepatic-artery and presence of associated anomalies can be a differential point of ALGS.

Theoretical and experimental studies for high-repetition-rate disordered crystal lasers with harmonic self-mode locking

A harmonically self-mode-locked Nd:Sr3Y2/(BO3)4 disordered crystal laser with subpicosecond pulse duration is demonstrated. We exploit the damped harmonic oscillator model to numerically verify that the mode spacing of the laser cavity can be modified to be the harmonics of the free spectral range of the Fabry-Perot cavity when the optical length of the laser cavity is close to a commensurate ratio of the optical length of the Fabry-Perot cavity. In experiment, the Fabry-Perot cavity can be formed by the pump facet of the disordered crystal and the front mirror. A 110 GHz single-pulse harmonically mode-locked pulse train with pulse duration of 857 fs is experimentally achieved under optical lengths of 27.19 and 4.08 mm for the laser cavity and Fabry-Perot cavity respectively, corresponding to a fractional number of 20/3. A maximum output power of 162 mW is obtained at an incident pump power of 3.1 W.

Quantitative Sonographic Texture Analysis in Preterm Neonates With White Matter Injury: Correlation of Texture Features With White Matter Injury Severity

OBJECTIVES

To analyze the texture features on cranial sonography in preterm neonates with white matter injury quantitatively and to correlate these features with magnetic resonance imaging (MRI).

METHODS

The study included 33 preterm neonates treated in our neonatal intensive care unit who underwent serial cranial sonography and brain MRI near term. Patients were subdivided into 3 groups according to the presence and severity of white matter injury as revealed by MRI: normal (group 1; n = 20), mild (group 2; n = 5), and severe (group 3; n = 8). The periventricular echogenicity on sonography was evaluated quantitatively with second-order gray-level statistics (gray-level co-occurrence matrix [GLCM] method). Four GLCM texture features representing homogeneity were extracted in 12 directions: (1) angular second moment (ASM), (2) inverse differential moment (IDM), (3) contrast, and (4) entropy.

RESULTS

Thirty of 48 features showed a statistically significant difference between groups 1 and 3 (ASM in 9 directions, IDM in 6 directions, contrast in 3 directions, and entropy in all 12 directions). There were no significant differences observed between groups 1 and 2 or groups 2 and 3. The mean contrast and entropy values were generally lower in group 1 than group 3, whereas the mean ASM and IDM values were higher in group 1.

CONCLUSIONS

Severe white matter injury could be identified by using GLCM texture analysis, whereas mild white matter injury observed on MRI could not be evaluated by GLCM analysis. Quantitative texture analysis using the GLCM may serve as a complementary tool for quantitative assessment of periventricular echogenicity.

Ultrasonographic Diagnosis of Biliary Atresia Based on a Decision-Making Tree Model

Objective

To assess the diagnostic value of various ultrasound (US) findings and to make a decision-tree model for US diagnosis of biliary atresia (BA).

Materials and Methods

From March 2008 to January 2014, the following US findings were retrospectively evaluated in 100 infants with cholestatic jaundice (BA, n = 46; non-BA, n = 54): length and morphology of the gallbladder, triangular cord thickness, hepatic artery and portal vein diameters, and visualization of the common bile duct. Logistic regression analyses were performed to determine the features that would be useful in predicting BA. Conditional inference tree analysis was used to generate a decision-making tree for classifying patients into the BA or non-BA groups.

Results

Multivariate logistic regression analysis showed that abnormal gallbladder morphology and greater triangular cord thickness were significant predictors of BA (p = 0.003 and 0.001; adjusted odds ratio: 345.6 and 65.6, respectively). In the decision-making tree using conditional inference tree analysis, gallbladder morphology and triangular cord thickness (optimal cutoff value of triangular cord thickness, 3.4 mm) were also selected as significant discriminators for differential diagnosis of BA, and gallbladder morphology was the first discriminator. The diagnostic performance of the decision-making tree was excellent, with sensitivity of 100% (46/46), specificity of 94.4% (51/54), and overall accuracy of 97% (97/100).

Conclusion

Abnormal gallbladder morphology and greater triangular cord thickness (> 3.4 mm) were the most useful predictors of BA on US. We suggest that the gallbladder morphology should be evaluated first and that triangular cord thickness should be evaluated subsequently in cases with normal gallbladder morphology.

Comparison of Image Quality and Radiation Dose between High-Pitch Mode and Low-Pitch Mode Spiral Chest CT in Small Uncooperative Children: The Effect of Respiratory Rate

OBJECTIVES

To compare image quality and radiation dose between high-pitch mode (HPM) and low-pitch mode (LPM) CT in young children.

MATERIALS AND METHODS

Forty-seven children (mean age 35.6 months; range, 0-126 months) underwent 49 CT examinations in HPM or LPM and were divided into high or low respiratory rate (RR) groups. A qualitative image quality was compared between the two modes. The volume CT dose index (CTDIvol) and dose-length product (DLP) were evaluated from the dose reports, and effective doses were assessed using a paediatric phantom.

RESULTS

Image quality was generally better for HPM than LPM (diagnostic acceptance score, 4.00 vs. 3.46, P = 0.004); the difference was more prominent in the high RR group (4.00 vs. 3.22, P = 0.001). However, there was no significant difference in the low RR group. The mean DLP value was higher in HPM than LPM (29.48 mGy · cm vs. 23.46 mGy · cm, P = 0.022), while CTDIvol was not significantly different. The total effective radiation dose was 26 % higher in HPM than LPM (1.82 mSv vs. 1.44 mSv).

CONCLUSIONS

LPM can be considered for paediatric lung evaluation in young children with low RRs to reduce radiation dose while maintaining favourable image quality.

KEY POINTS

• Radiation exposure is higher on high-pitch "Flash spiral mode" than on low-pitch "X-CARE mode". • "Flash spiral mode" generally showed better image quality than "X-CARE mode". • Difference in image quality was more prominent in the high RR group. • There was no difference in image quality in the low RR group. • "X-CARE mode" should be considered in a limited population with low RRs.

Ultrasound-guided contrast enema for meconium obstruction in very low birth weight infants: Factors that affect treatment success

INTRODUCTION

This study aimed to assess the therapeutic results of ultrasound (US)-guided water-soluble contrast enema in very low birth weight (VLBW) preterm infants (<1,500 g) with meconium obstruction and to study factors that affect therapeutic results.

METHODS

This study included a total of 33 consecutive VLBW infants with clinically diagnosed meconium obstruction underwent US-guided water-soluble contrast enema, from April 2007 to March 2014. Patients were classified into two groups based on to procedure outcome: the success group (evacuation of the meconium plug resolution followed by improved bowel distention within 2 days of the procedure, without additional interventions), and the failure group (the contrast enema failed to relieve the obstruction, or other procedure-related complications occurred). Patient- and mother-related clinical factors and procedure-related factors were compared between both groups.

RESULTS

Overall success rate was 54.5%, with 18 successful (M:F=10:8), and 15 failure (M:F=7:8) cases. When compared with the failure group, the success group patients showed statistically significant older gestational age (29(+1) vs. 27 weeks; p=0.028), larger birth weight (1023.1g vs. 790.3g; p=0.048), and higher body weight on the day of the procedure (1036.2g vs. 801.6g, p=0.049). However, no statistically significant differences were seen between other patient and maternal factors. Among the procedure-related factors, retrial of contrast injection during the procedure was associated with significantly higher success than the single trial (p=0.027). The presence of refluxed contrast into the distal ileum was the statistically significant predictor for success of the procedure (p=0.038). There were three cases of bowel perforation (9.1% per person).

CONCLUSION

US-guided water-soluble contrast enema in VLBW infants with meconium obstruction showed a 54.5% success rate and a 9.1% perforation rate per person. Among the procedure-related factors, retrial of contrast injection during the procedure and the presence of refluxed contrast into the distal ileum were related to the success of the procedure.

Reconstruction algorithm for nasal basal cell carcinoma with skin involvement only: analysis of 221 cases repaired by minor surgery

BACKGROUND

Basal cell carcinoma (BCC) often occurs on the nose. Reconstruction of the nose should yield excellent aesthetic and functional outcomes.

AIM

We propose a technical algorithm for the reconstruction of surgical defects, based on our analysis of 221 cases of nasal BCC with skin involvement only, which could be repaired by minor surgery.

METHODS

The aesthetic and functional outcomes for various reconstruction techniques were analysed according to defect location and size. A reconstruction algorithm was proposed with the aim of obtaining the best surgical results.

RESULTS

Defect location and size were key considerations. Primary closure was the first option for small defects (< 10 mm), with scores of 3.4 for objective aesthetic outcome (OAO), 3.2 for subjective aesthetic outcome (SAO) and 3.3 for subjective functional outcome (SFO). The first option for medium defects (1-20 mm) was the island pedicle flap, with scores of 3.5 for OAO, 3.2 for SAO and 3.7 for SFO. The first option for large defects (> 20 mm) was the transposition flap for the upper nose (scores of 2.0 for OAO and SAO and 3.0 for SFO) and the interpolation flap for the lower nose (2.8 for OAO and 2.9 for SAO and SFO).

CONCLUSIONS

We have proposed an algorithm to select the optimal technique for repairing nasal BCC surgical defects according to their size and location.

Transient flow response after femoral artery catheterization for diagnostic neuroangiography in infants and children: Doppler US assessment of the ipsilateral femoral artery

BACKGROUND

Hemodynamic changes in the distal arteries during transfemoral catheterization in children have not been documented.

OBJECTIVE

To evaluate arterial flow changes of the lower extremities ipsilateral to the puncture site using Doppler US during transfemoral cerebral angiography in children.

MATERIALS AND METHODS

Twenty-seven children who underwent transfemoral cerebral angiography at our institution between April 2013 and August 2013 compose our study population. Doppler US was performed to evaluate diameters and peak systolic velocities of the common femoral artery and superficial femoral artery before and after femoral sheath insertion. Children were classified into three groups based on the spectral waveform changes of the superficial femoral artery after femoral sheath insertion. Thereafter, one-way ANOVA followed by the Bonferroni post-hoc comparisons test were performed to compare values among the groups.

RESULTS

Mean common femoral artery and superficial femoral artery baseline diameters were 4.10 mm and 3.32 mm, and mean baseline peak systolic velocities were 218.26 and 166.51 cm/s, respectively. Fourteen of 27 children showed persistent triphasic flow in the superficial femoral artery (group 1); 7 children showed altered flow of biphasic (n = 3) or monophasic (n = 4) waveforms (group 2); and 6 children showed pulsus tardus et parvus pattern (group 3) after femoral sheath insertion. Mean baseline diameter of the common femoral artery and mean subtracted value between common femoral artery and femoral sheath size were significantly smaller in group 3 than the other groups. Size discrepancy between common femoral artery and femoral sheath was <1 mm in all cases of group 3. Superficial femoral artery diameter and peak systolic velocity significantly decreased after femoral sheath insertion in group 3 compared to groups 1 and 2. A significant skin temperature drop after sheath insertion in the ipsilateral lower extremity was noted in group 3 (-1.83°C), compared to groups 1 and 2 (+0.42 and -0.86°C, respectively).

CONCLUSION

Changes in the spectral waveforms of superficial femoral arteries frequently occur in children during transfemoral cerebral angiography (13/27, 48%). Significant arterial flow disturbance was noted on Doppler US in children with a common femoral artery <1 mm larger than the femoral sheath diameter.

Association between pelvic organ prolapse and bone mineral density in postmenopausal women

Both pelvic organ prolapse (POP) and osteoporosis are age-related diseases in older aged women. Both POP and bone metabolism may be associated with collagen metabolism. Our study determined the relationship between POP and bone mineral density (BMD) of the lumbar spine and femur neck in postmenopausal women. We selected 554 postmenopausal women (aged 50-79 years) and divided them into two groups (moderate to severe POP and absent to mild POP). We compared the BMDs of the lumbar spine and femur neck between the moderate to severe POP and absent to mild POP groups. Lumbar spine BMD was inversely correlated with POP severity (p = 0.001). However, after adjusting for age, time since menopause, height, weight, body mass index (BMI), and vaginal delivery, the BMDs of both the lumbar spine and femur neck were not significantly different between the moderate to severe POP and absent to mild POP groups (p = 0.583 and p = 0.305, respectively). A lower BMD is associated with increased fracture risk and we postulated that women with severe POP would have an increased risk of osteoporotic fracture.

Immunohistochemical changes of adenomyosis after heat therapy: comparison of radiofrequency myolysis and endoablation

PURPOSE

To check the pathologic changes of focal adenomyosis after heat therapy using radiofrequency and to evaluate which approach--endometrial ablation or direct heat therapy--is better for adenomyosis. To evaluate whether the timing of the procedure and the menstrual cycle are related to pathologic outcomes after heat therapy.

METHODS

This study included nine women who underwent total hysterectomy for adenomyosis (diameter, > or = 6 cm). Six fresh uteri were excised in the midline and subjected to radiofrequency heat therapy at the center of the adenomyomas (direct heat therapy) and three uteri were subjected to endometrial ablation. Thereafter, 1 cm(3) myometrial tissue was obtained at 1 cm, 2 cm, and 3 cm away from the endometrium. Tissue sections were stained with hematoxylin and eosin. Immunohistochemical analysis using antibodies against cytokerain-19 (CK-19), actin, and estrogen receptor/progesterone receptor (ER/PR) was performed to evaluate CK-19 (endometrial epithelium marker), actin (myometrial marker) and ER/PR (checking the state of the menstrual cycle), respectively.

RESULTS

After endometrial ablation, cauterized tissues were not noted 2 cm away from the endometrium. All tissues between the endometruim and center of adenomyosis were cauterized after direct heat therapy. During the uterine proliferative phase, unlike the secretory phase, subendometrial layers were cauterized 10 min after direct cauterization.

CONCLUSION

Direct heat therapy is more effective than endometrial ablation in adenomyosis, and heat is conducted effectively when the patients are in the proliferative phase.

Analysis of particle laden flow and heat transfer in cascade and rocket nozzle

This paper presents results for the calculation of particle trajectories in a cascade and a rocket nozzle using a Lagrangian method. When the floating particles collide to the components, the component surface is damaged severely. The surface erosion rate is strongly dependent on a particle size, a particle impact angle and a surface material. For a compressor cascade, the particle impact rate increases proportionally with the flow inlet angle and the erosion rate on the pressure side surface of blade are related to the surface or coating materials. For a solid rocket nozzle, the particle free zone in the nozzle divergent section increases quickly with increasing particle size and the maximum heat transfer density occurs at the starting region of nozzle convergent section. The Al2O3 droplet breaks up around the nozzle throat due to the high velocity difference between the droplet and gas stream, resulting in the big change of particle free zone.

Inhibitory effect of mast cell-mediated immediate-type allergic reactions in rats by spirulina

We investigated the effect of spirulina on mast cell-mediated immediate-type allergic reactions. Spirulina dose-dependently inhibited the systemic allergic reaction induced by compound 48/80 in rats. Spirulina inhibited compound 48/80-induced allergic reaction 100% with doses of 100-1000 microg/g body weight, i.p. Spirulina (10-1000 microg/g body weight, i.p.) also significantly inhibited local allergic reaction activated by anti-dinitrophenyl (DNP) IgE. When rats were pretreated with spirulina at a concentration ranging from 0.01 to 1000 microg/g body weight, i.p., the serum histamine levels were reduced in a dose-dependent manner. Spirulina (0.001 to 10 microg/mL) dose-dependently inhibited histamine release from rat peritoneal mast cells (RPMC) activated by compound 48/80 or anti-DNP IgE. The level of cyclic AMP in RPMC, when spirulina (10 microg/mL) was added, transiently and significantly increased about 70-fold at 10 sec compared with that of control cells. Moreover, spirulina (10 microg/mL) had a significant inhibitory effect on anti-DNP IgE-induced tumor necrosis factor-alpha production. These results indicate that spirulina inhibits mast cell-mediated immediate-type allergic reactions in vivo and in vitro.