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.

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.

Time-saving synthetic magnetic resonance imaging protocols for pediatric neuroimaging: impact of echo train length and bandwidth on image quality.

BACKGROUND: Synthetic MRI is a time-efficient imaging technique that provides both quantitative MRI and contrast-weighted images simultaneously. However, a rather long single scan time can be challenging for children. OBJECTIVE: To evaluate the clinical feasibility of time-saving synthetic MRI protocols adjusted for echo train length and receiver bandwidth in pediatric neuroimaging based on image quality assessment and quantitative data analysis. MATERIALS AND METHODS: In total, we included 33 children ages 1.6-17.4 years who underwent synthetic MRI using three sets of echo train length and receiver bandwidth combinations (echo train length [E]12-bandwidth [B in KHz]22, E16-B22 and E16-B83) at 3 T. The image quality and lesion conspicuity of synthetic contrast-weighted images were compared between the suggested protocol (E12-B22) and adjusted protocols (E16-B22 and E16-B83). We also compared tissue values (T1, T2, proton-density values) and brain volumetry. RESULTS: For the E16-B83 combination, image quality was sufficient except for 15.2% of T1-W and 3% of T2-W fluid-attenuated inversion recovery (FLAIR) images, with remarkable scan time reduction (up to 35%). The E16-B22 combination demonstrated a comparable image quality to E12-B22 (P>0.05) with a scan time reduction of up to 8%. There were no significant differences in lesion conspicuity among the three protocols (P>0.05). Tissue value measurements and brain tissue volumes obtained with the E12-B22 protocol and adjusted protocols showed excellent agreement and strong correlations except for gray matter volume and non-white matter/gray matter/cerebrospinal fluid volume in E12-B22 vs. E16-B83. CONCLUSION: The adjusted synthetic protocols produced image quality sufficient or comparable to that of the suggested protocol while maintaining lesion conspicuity with reduced scan time. The quantitative values were generally consistent with the suggested MRI-protocol-derived values, which supports the clinical application of adjusted protocols in pediatric neuroimaging.

Blinatumomab-related pneumatosis intestinalis in a pediatric patient with relapsed acute lymphoblastic leukemia: A case report.

INTRODUCTION: Pneumatosis intestinalis is characterized by air in the subserosal or submucosal layer of the intestine, with the severity ranging from mild and asymptomatic to symptomatic with serious conditions such as intestinal ischemia and perforation requiring surgery. Although several etiologies, including those from conventional chemotherapy agents and molecular target agents, have been suggested, blinatumomab-related pneumatosis intestinalis is quite rare. CASE REPORT: An 11-year-old girl with history of B-cell ALL presented with bone marrow relapse 3 years after completion of initial chemotherapy. Reinduction chemotherapy and blinatumomab as post-reinduction consolidation were initiated. On day 28 of blinatumomab therapy, pneumatosis intestinalis from the ascending colon to the hepatic flexure was found incidentally on abdominal computed tomography.Management and outcome: After withholding blinatumomab therapy for 1 month, pneumatosis intestinalis improved significantly without abnormal gastrointestinal symptoms. Blinatumomab was resumed and safely completed. The computed tomography performed 4 months later showed complete resolution of pneumatosis intestinalis. The patient has been in good condition for over 1 year to date. DISCUSSION: To our knowledge, this is the first case report of pneumatosis intestinalis after blinatumomab therapy in a pediatric patient with relapsed precursor B-cell acute lymphoblastic leukemia. Herein, we highlight the importance of early detection of pneumatosis intestinalis through imaging follow-up during blinatumomab therapy.

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.

Pediatric head computed tomography with advanced modeled iterative reconstruction: focus on image quality and reduction of radiation dose.

BACKGROUND: Iterative reconstruction has become the standard method for reconstructing computed tomography (CT) scans and needs to be verified for adaptation. OBJECTIVE: To assess the image quality after adapting advanced modeled iterative reconstruction (ADMIRE) for pediatric head CT. MATERIALS AND METHODS: We included image sets with filtered back projection reconstruction (the cFBP group, n=105) and both filtered back projection and ADMIRE reconstruction (the lower-dose group, n=109) after dose reduction. All five strength levels of ADMIRE and filtered back projection were adapted for the lower-dose group and compared with the cFBP group. Quantitative parameters including noise, signal-to-noise ratio and contrast-to-noise ratio and qualitative parameters including noise, white matter and gray matter differentiation of the supra- and infratentorial levels, sharpness, artifact, and diagnostic accuracy were also evaluated and compared with interobserver agreement. RESULTS: There was a mean dose reduction of 30.6% in CT dose index volume, 32.1% in dose length product, and 32.1% in effective dose after tube current reduction. There was gradual reduction of noise in air, cerebrospinal fluid and white matter with strength levels of ADMIRE from 1 to 5 (P<0.001). Signal-to-noise ratio and contrast-to-noise ratio in all age groups increased among strength levels of ADMIRE, in sequence from 1 to 5, with statistical significance (P<0.001). Gradual reduction of qualitative parameters was noted among strength levels of ADMIRE in sequence from 1 to 5 (P<0.001). CONCLUSION: Use of ADMIRE for pediatric head CT can reduce radiation dose without degrading image quality.

Restaging the axilla after neo-adjuvant chemotherapy for breast cancer: Predictive factors for residual metastatic lymph node disease with negative imaging findings.

To evaluate predictive factors for residual metastatic axillary lymph node (ALN) disease in patients with negative imaging findings after neo-adjuvant chemotherapy (NAC) for breast cancer. From January 2011 to December 2015, 206 patients underwent imaging including ultrasonography, MRI, and PET/CT for restaging the axilla after NAC. Data collected included preoperative information regarding histologic grade, hormone receptor (HR) status, and human epidermal growth factor receptor 2 (HER2) status. Multivariate logistic regression analysis was performed to compare patients with and without residual metastatic ALN disease among patients who showed negative imaging findings after NAC. Of the 181 and 25 patients with initially node-positive and node-negative disease, 131 (72.4%) and 23 (92.0%), respectively, showed negative imaging findings after NAC. Among these 131 and 23 patients, 53 (40.5%) and two patients (8.7%), respectively, had residual metastatic ALN disease. Low to moderate tumor grade (odds ratio [OR] = 5.2, P = 0.009), positive HR status (OR = 6.6, P = 0.003), and negative HER2 status (OR = 2.6, P = 0.048) were associated with residual metastatic ALN disease. Low to moderate histologic grade, positive HR status, and negative HER2 status may serve as predictors of residual metastatic ALN disease in patients with negative imaging findings after NAC for breast cancer.

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.

Susceptibility of the Index Urinary Tract Infection to Prophylactic Antibiotics Is a Predictive Factor of Breakthrough Urinary Tract Infection in Children with Primary Vesicoureteral Reflux Receiving Continuous Antibiotic Prophylaxis.

BACKGROUND: Few studies have reported on breakthrough urinary tract infection (UTI) associated with the susceptibility of index UTI to prophylactic antibiotics in children with primary vesicoureteral reflux (VUR) receiving continuous antibiotic prophylaxis (CAP). We assessed the impact of the susceptibility of index UTI to prophylactic antibiotics in breakthrough UTIs in children with primary VUR receiving CAP. METHODS: We retrospectively reviewed the medical records of 81 children with primary VUR who were diagnosed after febrile or symptomatic UTI and subsequently received trimethoprim-sulfamethoxazole (TMP-SMX) as CAP between January 2010 and December 2013. We allocated children to a susceptible group or a resistant group based on the susceptibility of index UTI to TMP-SMX. We evaluated patient demographics and clinical outcomes after CAP according to the susceptibility of index UTI to TMP-SMX. Multivariate analysis was used to identify the predictive factors for breakthrough UTI. RESULTS: Of the 81 children, 42 were classified into the susceptible group and 39 into the resistant group. The proportion of breakthrough UTI was 31.0% (13/42) in the susceptible group and 53.8% (21/39) in the resistant group (P = 0.037). Progression of renal scarring was observed in 0% of children in the susceptible group and 15% in the resistant group (P = 0.053). Multivariate analysis showed that TMP-SMX resistance and initial renal scarring were significant predictors of breakthrough UTI. CONCLUSION: Susceptibility of index UTI to prophylactic antibiotics is a risk factor of breakthrough UTI and is associated with poor clinical outcomes in children with primary VUR receiving CAP.

Preoperative MRI features associated with lymphovascular invasion in node-negative invasive breast cancer: A propensity-matched analysis.

PURPOSE: In node-negative disease, the presence of lymphovascular invasion (LVI) is reported to be an unfavorable prognostic factor. Thus, the aim of this study was to evaluate whether preoperative breast MRI features are associated with LVI in patients with node-negative invasive breast cancer by a propensity-matched analysis. MATERIALS AND METHODS: Among 389 patients with node-negative invasive ductal breast cancer who had preoperative breast 3.0 Tesla MRI with precontrast T2-weighted fat-suppressed, pre- and dynamic postcontrast T1-weighted fat-suppressed sequences, 61 patients with LVI (LVI group) were matched with 183 patients without LVI (no LVI group) at a ratio of 1:3 in terms of age, histologic grade, tumor size, and hormone receptor status. Two radiologists reviewed the MRI features, following profiles of focal breast edema (peritumoral, prepectoral, subcutaneous), intratumoral T2 signal intensity, adjacent vessel sign, and increased ipsilateral whole-breast vascularity, in addition to 2013 Breast Imaging Reporting and Data System lexicon. RESULTS: The presence of peritumoral edema (45.9% [28/61] versus 30.6% [56/183], P = 0.030) and adjacent vessel sign (82.0% [50/61] versus 68.3% [125/183], P = 0.041) was significantly associated with LVI. Prepectoral edema was also more frequently observed in the LVI group than in the no LVI group with borderline significance (26.2% [16/61] versus 15.3% [28/183], P = 0.055). In cases of nonmass enhancement, regional enhancement was more frequently found in the LVI group than in the no LVI group (60.0% [3/4] versus 5.9% [1/4], P = 0.042). CONCLUSION: Preoperative breast MRI features may be associated with LVI in patients with node-negative invasive breast cancer. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2017;46:1037-1044.

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.

Internal mammary node adenopathy on breast MRI and PET/CT for initial staging in patients with operable breast cancer: prevalence and associated factors.

PURPOSE: To evaluate the prevalence of and factors associated with internal mammary node (IMN) adenopathy on MRI and PET/CT used for initial staging in patients with operable breast cancer. METHODS: A total of 1320 patients diagnosed with invasive breast carcinoma between January 2011 and December 2015 underwent MRI and PET/CT for initial staging. The patients were considered to have IMN adenopathy when MRI revealed IMNs with the longest diameter of 5 mm or greater and a standardized uptake value greater than that of the mediastinal blood pool/contralateral parasternal area on PET/CT. The prevalence was determined as overall percentage of patients with IMN adenopathy, as well as percentages among patients who received neoadjuvant chemotherapy and those who did not. The association of IMN adenopathy with factors was evaluated using multivariate logistic regression analysis. RESULTS: Of the 1320 patients, 35 patients [2.7 %; 95 % confidence interval (CI) 1.8-3.6 %] had IMN adenopathy, with a total of 49 IMNs. Among patients without and with neoadjuvant chemotherapy (n = 1092 and n = 228, respectively), IMN adenopathy was identified in 13 (1.2 %; 95 % CI 0.6-2.0 %) and 22 patients (9.6 %; 95 % CI 6.0-14.6 %), respectively. Inner tumor location [odds ratio (OR) 5.9; P = .002] and positive axillary lymph node status (OR 4.4; P < .0001) were associated with IMN adenopathy. CONCLUSIONS: IMN adenopathy was identified at initial staging with PET/CT and MRI with a prevalence of 2.7 %. Inner tumor location and positive axillary lymph node status were associated with IMN adenopathy.

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.

Free-Breathing Radial 3D Fat-Suppressed T1-Weighted Gradient-Echo Sequence for Contrast-Enhanced Pediatric Spinal Imaging: Comparison With T1-Weighted Turbo Spin-Echo Sequence.

OBJECTIVE: The purpose of this study was to compare free-breathing radially sampled 3D T1-weighted gradient-echo acquisitions (radial volumetric interpolated breath-hold examination [VIBE]) with a T1-weighted turbo spin-echo (TSE) sequence for contrast-enhanced spinal imaging of children with CNS tumors. MATERIALS AND METHODS: Twenty-eight consecutively registered children with CNS tumors underwent evaluation of leptomeningeal seeding with 1.5-T MRI that included both radial VIBE and T1-weighted TSE sequences. For qualitative analysis, overall image quality; presence of motion, CSF flow, and radial artifacts; and lesion conspicuity were retrospectively assessed with scoring systems. The signal-intensity uniformity of each sequence was evaluated for quantitative comparison. The acquisition times for each sequence were compared. RESULTS: Images obtained with the radial VIBE sequence had a higher overall image quality score than did T1-weighted TSE images (3.61 ± 0.73 vs 2.80 ± 0.69, p < 0.001) and lower motion artifact (0.82 ± 0.43 vs 1.29 ± 0.56, p = 0.001) and CSF flow artifact (0 vs 1.68 ± 0.67, p < 0.001) scores. Radial artifacts were found only on radial VIBE images (1.36 ± 0.31 vs 0, p < 0.001). In 13 patients with spinal seeding nodules, radial VIBE images showed greater lesion conspicuity than did T1-weighted TSE images (4.23 ± 0.52 vs 2.47 ± 0.57, p = 0.005). Radial VIBE images had diminished signal-intensity variation compared with T1-weighted TSE images in air, spine, and muscle (p < 0.01). The mean acquisition times were not significantly different between the two sequences (p = 0.117). CONCLUSION: For pediatric spinal imaging, radial VIBE images had better image quality and lesion conspicuity and fewer CSF and respiratory motion artifacts than did T1-weighted TSE images in a similar acquisition time.

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 99m­labeled 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.

Prediction of High-grade Vesicoureteral Reflux in Children Younger Than 2 Years Using Renal Sonography: A Preliminary Study.

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.

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.

Pediatric Chest CT: Wide-Volume and Helical Scan Modes in 320-MDCT.

OBJECTIVE: The purpose of this study was to compare wide-volume and helical pediatric 320-MDCT of the chest with respect to radiation dose and image quality. MATERIALS AND METHODS: From November 2012 to September 2013, 59 wide-volume and 47 helical pediatric chest 320-MDCT images were obtained. The same tube potential and effective tube current-time product were applied in the two groups according to patient weight (group A, < 10 kg, n = 18; group B, 10-19.9 kg, n = 60; group C, 20-39.9 kg, n = 28). To compensate for overranging, adjusted CT dose index (CTDI) was calculated by dividing dose-length product (DLP) by the scan ranges imaged. Adjusted CTDI, DLP, overall image quality, motion artifact, noise, and scan ranges were compared by Mann-Whitney U test or t test. RESULTS: The adjusted CTDI was significantly lower in the group who underwent wide-volume CT than in the group who underwent helical CT (weight group A, p < 0.001; group B, p < 0.001; group C, p = 0.003). The DLP was lower in the wide-volume group than in the helical CT group in weight groups A (p < 0.001) and B (p < 0.001) but not in group C (p = 0.162). All CT scans were of diagnostic quality, and there was no significant difference between the wide-volume and helical CT groups (p = 0.318). The motion artifact score was significantly higher in the wide-volume group than in the helical CT group in groups B (p < 0.001) and C (p = 0.010) but not in group A (p = 0.931). The noise was significantly lower in the wide-volume group than in the helical CT group (p < 0.001). CONCLUSION: In pediatric chest CT, use of wide-volume CT can decrease radiation exposure while preserving image quality. It is associated with less noise than helical CT but may be subject to more motion artifact.

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.