Improving Reproducibility of Volumetric Evaluation Using Computed Tomography in Pediatric Patients with Congenital Heart Disease.

The volumetric data obtained from the cardiac CT scan of congenital heart disease patients is important for defining patient's status and making decision for proper management. The objective of this study is to evaluate the intra-observer, inter-observer, and interstudy reproducibility of left ventricular (LV) and right ventricular (RV) or functional single-ventricle (FSV) volume. And compared those between manual and using semi-automated segmentation tool. Total of 127 patients (56 female, 71 male; mean age 82.1 months) underwent pediatric protocol cardiac CT from January 2020 to December 2022. The volumetric data including both end-systolic and -diastolic volume and calculated EF were derived from both conventional semiautomatic region growing algorithms (CM, TeraRecon, TeraRecon, Inc., San Mateo, CA, USA) and deep learning-based annotation program (DLS, Medilabel, Ingradient, Inc., Seoul, Republic of Korea) by three readers, who have different background knowledge or experience of radiology or image extraction before. The reproducibility was compared using intra- and inter-observer agreements. And the usability was measured using time for reconstruction and number of tests that were reconfigured before the reconfiguration time was reduced to less than 5 min. Inter- and intra-observer agreements showed better agreements degrees in DLS than CM in all analyzers. The time used for reconstruction showed significantly shorter in DLS compared with CM. And significantly small numbers of tests before the reconfiguration is needed in DLS than CM. Deep learning-based annotation program can be more accurate way for measurement of volumetric data for congenital heart disease patients with better reproducibility than conventional method.

Assessment of deep learning image reconstruction (DLIR) on image quality in pediatric cardiac CT datasets type of manuscript: Original research.

BAKGROUND: To evaluate the quantitative and qualitative image quality using deep learning image reconstruction (DLIR) of pediatric cardiac computed tomography (CT) compared with conventional image reconstruction methods. METHODS: Between January 2020 and December 2022, 109 pediatric cardiac CT scans were included in this study. The CT scans were reconstructed using an adaptive statistical iterative reconstruction-V (ASiR-V) with a blending factor of 80% and three levels of DLIR with TrueFidelity (low-, medium-, and high-strength settings). Quantitative image quality was measured using signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). The edge rise distance (ERD) and angle between 25% and 75% of the line density profile were drawn to evaluate sharpness. Qualitative image quality was assessed using visual grading analysis scores. RESULTS: A gradual improvement in the SNR and CNR was noted among the strength levels of the DLIR in sequence from low to high. Compared to ASiR-V, high-level DLIR showed significantly improved SNR and CNR (P<0.05). ERD decreased with increasing angle as the level of DLIR increased. CONCLUSION: High-level DLIR showed improved SNR and CNR compared to ASiR-V, with better sharpness on pediatric cardiac CT scans.

[Normal Development and Variants in Pediatric Bone]. / 소아 뼈의 ì •ìƒ 발달과 변이.

Normal variants refer to imaging findings that are generally asymptomatic and discovered incidentally, yet may exhibit findings similar to those observed in pathological conditions. Recognizing normal variants in pediatric bone requires comprehension of the developmental process of long tubular bones and secondary ossification centers. Familiarity with various radiological findings of normal variants can prevent unnecessary follow-up imaging tests, as well as incorrect diagnosis and treatment. In this review, we will discuss the characteristic imaging findings of normal variants seen in growing pediatric bones, along with strategies for distinguishing them from pathologic conditions.

Hepatic T-cell senescence and exhaustion are implicated in the progression of fatty liver disease in patients with type 2 diabetes and mouse model with nonalcoholic steatohepatitis.

Immunosenescence and exhaustion are involved in the development and progression of type 2 diabetes (T2D) and metabolic liver diseases, including fatty liver, fibrosis, and cirrhosis, in humans. However, the relationships of the senescence and exhaustion of T cells with insulin resistance-associated liver diseases remain incompletely understood. To better define the relationship of T2D with nonalcoholic fatty liver disease, 59 patients (mean age 58.7 ± 11.0 years; 47.5% male) with T2D were studied. To characterize their systemic immunophenotypes, peripheral blood mononuclear cells were analyzed using flow cytometry. Magnetic resonance imaging (MRI)-based proton density fat fraction and MRI-based elastography were performed using an open-bore, vertical-field 3.0 T scanner to quantify liver fat and fibrosis, respectively. The participants with insulin resistance had a significantly larger population of CD28 - CD57+ senescent T cells among the CD4+ and CD8 + T cells than those with lower Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) values. The abundances of senescent CD4+ and CD8 + T cells and the HOMA-IR positively correlated with the severity of liver fibrosis, assessed using MRI-based elastography. Interleukin 15 from hepatic monocytes was found to be an inducer of bystander activation of T cells, which is associated with progression of liver disease in the participants with T2D. Furthermore, high expression of genes related to senescence and exhaustion was identified in CD4+ and CD8 + T cells from the participants with nonalcoholic steatohepatitis or liver cirrhosis. Finally, we have also demonstrated that hepatic T-cell senescence and exhaustion are induced in a diet or chemical-induced mouse model with nonalcoholic steatohepatitis. In conclusion, we have shown that T-cell senescence is associated with insulin resistance and metabolic liver disease in patients with T2D.

Neuroimaging of Germinal Matrix and Intraventricular Hemorrhage in Premature Infants.

Germinal matrix and intraventricular hemorrhage (GM-IVH) are the major causes of intracranial hemorrhage in premature infants. Cranial ultrasound (cUS) is the imaging modality of choice for diagnosing and classifying GM-IVH. Magnetic resonance imaging (MRI), usually performed at term-equivalent age, is more sensitive than cUS in identifying hemorrhage in the brain. Post-hemorrhagic ventricular dilatation is a significant complication of GM-IVH and correlates with adverse neurodevelopmental outcomes. In this review, we discuss the various imaging findings of GM-IVH in premature infants, focusing on the role of cUS and MRI.

Rare Case of Large Hemolymphangioma in the Small Bowel Mesentery: A Case Report.

Hemolymphangioma or hemangiolymphangioma is a rare venolymphatic vascular malformation composed of proliferations or networks of vascular spaces including the lymphatics, capillaries, veins, or arteries. The small bowel is a rare location for hemolymphangioma, and the small bowel mesentery is an even rarer site. Herein, we report a surgically confirmed large complex hemolymphangioma in the small bowel mesentery in a 55-year-old male.

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.

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.

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

Purpose: To evaluate the feasibility of pediatric low-dose facial CT reconstructed with filtered back projection (FBP) using adequate kernels. Materials and Methods: We retrospectively reviewed the clinical and imaging data of children aged < 10 years who underwent facial CT at our emergency department. The patients were divided into two groups: low-dose CT (LDCT; Group A, n = 73) with a fixed 80-kVp tube potential and automatic tube current modulation (ATCM) and standard-dose CT (SDCT; Group B, n = 40) with a fixed 120-kVp tube potential and ATCM. All images were reconstructed with FBP using bone and soft tissue kernels in Group A and only bone kernel in Group B. The groups were compared in terms of image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR). Two radiologists subjectively scored the overall image quality of bony and soft tissue structures. The CT dose index volume and dose-length product were recorded. Results: Image noise was higher in Group A than in Group B in bone kernel images (p < 0.001). Group A using a soft tissue kernel showed the highest SNR and CNR for all soft tissue structures (all p < 0.001). In the qualitative analysis of bony structures, Group A scores were found to be similar to or higher than Group B scores on comparing bone kernel images. In the qualitative analysis of soft tissue structures, there was no significant difference between Group A using a soft tissue kernel and Group B using a bone kernel with a soft tissue window setting (p > 0.05). Group A showed a 76.9% reduction in radiation dose compared to Group B (3.2 ± 0.2 mGy vs. 13.9 ± 1.5 mGy; p < 0.001). Conclusion: The addition of a soft tissue kernel image to conventional CT reconstructed with FBP enables the use of pediatric low-dose facial CT protocol while maintaining image quality.

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.

Noninvasive Assessment of Liver Fibrosis with ElastPQ in Patients with Chronic Viral Hepatitis: Comparison Using Histopathological Findings.

Chronic viral hepatitis is a major cause of chronic liver disease leading to liver fibrosis. This study aimed to assess the diagnostic performance of elastography point quantification (ElastPQ), transient elastography (TE), and aspartate aminotransferase-to-platelet count ratio index (APRI) for the staging of liver fibrosis in patients with chronic viral hepatitis using histopathological findings as a reference standard. For 122 patients with chronic viral hepatitis, diagnostic performance was evaluated using area under the receiver operating characteristic curve (AUROC) analysis and correlations were determined using Spearman's correlation coefficient. The AUROC of ElastPQ for the diagnosis of the fibrosis stage ≥ F2 was 0.917 with a cut-off value of 3.935. There was a significant positive correlation between the different stages of histologic liver fibrosis and stiffness values obtained using ElastPQ, TE, and APRI (ρ = 0.556, ρ = 0.657, ρ = 0.375, respectively; p < 0.001). ElastPQ showed a higher diagnostic accuracy than APRI, resembling that of TE; AUROC values of ElastPQ, TE, and APRI were 0.917, 0.964, and 0.896, respectively, for a fibrosis stage ≥ F2. ElastPQ is a promising noninvasive technique with a diagnostic accuracy comparable with that of TE for the evaluation of liver fibrosis in patients with chronic viral hepatitis.

Denoising of pediatric low dose abdominal CT using deep learning based algorithm.

OBJECTIVES: To evaluate standard dose-like computed tomography (CT) images generated by a deep learning method, trained using unpaired low-dose CT (LDCT) and standard-dose CT (SDCT) images. MATERIALS AND METHODS: LDCT (80 kVp, 100 mAs, n = 83) and SDCT (120 kVp, 200 mAs, n = 42) images were divided into training (42 LDCT and 42 SDCT) and validation (41 LDCT) sets. A generative adversarial network framework was used to train unpaired datasets. The trained deep learning method generated virtual SDCT images (VIs) from the original LDCT images (OIs). To test the proposed method, LDCT images (80 kVp, 262 mAs, n = 33) were collected from another CT scanner using iterative reconstruction (IR). Image analyses were performed to evaluate the qualities of VIs in the validation set and to compare the performance of deep learning and IR in the test set. RESULTS: The noise of the VIs was the lowest in both validation and test sets (all p<0.001). The mean CT number of the VIs for the portal vein and liver was lower than that of OIs in both validation and test sets (all p<0.001) and was similar to those of SDCT. The contrast-to-noise ratio of portal vein and the signal-to-noise ratio (SNR) of portal vein and liver of VIs were higher than those of SDCT (all p<0.05). The SNR of VIs in test sets was the highest among three images. CONCLUSION: The deep learning method trained by unpaired datasets could reduce noise of LDCT images and showed similar performance to SAFIRE. It can be applied to LDCT images of older CT scanners without IR.

Clinical Significance of Pancreatic Fat in Children: A Single-Center Experience.

OBJECTIVES: Recently, interest in pancreatic fat has increased, and fatty pancreas is considered to be related to nonalcoholic fatty liver disease (NAFLD) and metabolic syndrome. We aimed to evaluate the prevalence of echogenic pancreas in children and its related factors. METHODS: We retrospectively analyzed the data of patients aged 5 to 18 years who had undergone abdominal sonography between January 2020 and December 2020. Patients with chronic or pancreatic diseases were excluded. RESULTS: Of 102 patients, 27 (26.5%) had echogenic pancreas and 55 (53.9%) had NAFLD. Among the 55 patients with NAFLD, 18 (32.7%) had an echogenic pancreas. Patients with echogenic pancreas had significantly higher fasting glucose, low-density lipoprotein cholesterol, and triglyceride levels than those without echogenic pancreas. The proportion of NAFLD and obesity was higher in the echogenic group; however, only the proportion of obese subjects showed a significant difference. In multivariate analysis, family history of diabetes mellitus (DM) and/or dyslipidemia and presence of DM and/or dyslipidemia were factors related to the presence of echogenic pancreas. CONCLUSIONS: Echogenic pancreas is relatively common in children. Echogenic pancreas, typically observed in patients with a family history of DM and/or dyslipidemia, was strongly associated with metabolic syndrome, even in the absence of fatty liver.

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.

Sarcomatoid carcinoma of the pancreas - multimodality imaging findings with serial imaging follow-up: A case report and review of literature.

BACKGROUND: Sarcomatoid carcinoma of the pancreas is extremely rare and has an extremely poor prognosis. Although a few cases of sarcomatoid carcinoma of pancreas have been reported, most are focused on a histopathological review. To the best of our knowledge, there are no reports documenting multimodality imaging characteristics and chronological changes with emphasis on radiologic features. CASE SUMMARY: A 64-year-old woman was admitted to Chungnam National University Hospital with acute appendicitis. Contrast-enhanced computed tomography of the abdomen revealed a 2.6 cm × 2.8 cm multilobular cystic mass in the pancreatic tail. The pancreatic lesion showed suspected mural nodules and thin septa. Hence, mucinous cystic neoplasm of pancreas was considered. After 7 mo, the patient was readmitted for repeated epigastric abdominal pain and nausea. Follow-up contrast-enhanced computed tomography of the abdomen and magnetic resonance imaging revealed a marked enlargement (5.4 cm × 4 cm), with a predominant internal solid component. The mass showed low signal intensity on a T1-weighted image and heterogeneously intermediate high signal intensity on a T2-weighted image. It showed diffusion restriction and peripheral rim enhancement on an arterial phase image, and progressive enhancement on portal venous and delayed phase images. Distal pancreatectomy was performed. Based on the morphology and immunohistochemical staining of the specimen, pancreatic sarcomatoid carcinoma was diagnosed. CONCLUSION: We present the computed tomography, magnetic resonance imaging, and positron emission tomography computed tomography findings, pathologic features, and chronological changes for preoperative diagnosis.

Bilateral optic neuropathy following vincristine chemotherapy: A case report with description of multimodal imaging findings.

RATIONALE: A few cases of optic neuropathy presumed to be caused by vincristine have been reported. However, none described multimodal imaging findings. Here, we report abnormal magnetic resonance imaging (MRI) and optical coherence tomography (OCT) findings in a putative case of vincristine-induced optic neuropathy. PATIENT CONCERNS: A 9-year-old boy with Burkett lymphoma who had had no visual problems noticed blurred vision in both eyes 22 days after the first maintenance therapy for lymphoma; the blurred gradually worsened. At that time, the best-corrected visual acuity was 20/200 and 20/100 in the right and left eyes, respectively. DIAGNOSES: Blood and imaging workup, and cerebrospinal fluid and genetic analyses, were performed; these included fundus photography, OCT, and MRI. We found no plausible cause of the optic neuropathy other than vincristine. INTERVENTIONS: The scheduled chemotherapy was stopped, and the patient was managed with high-dose corticosteroids. However, as there was no improvement, plasma exchange was then performed. OUTCOMES: Three days after the initial examination, the visual acuity in both eyes was only light perception and projection. Signal intensity was abnormally high on 3-dimensional T2-weighted turbo spin echo and T2-weighted MRI images. Optic disc atrophy progressed to "total pallor"; thinning of the ganglion cell-inner plexiform and retinal nerve fiber layers also progressed. The patient was followed up for 7 months but showed no improvement in vision. There were no treatment-related complications. LESSONS: We conclude that vincristine can cause optic neuropathy, and clinicians need to be alert to the possibility of optic neuropathy in any patient prescribed this agent.OCT and MRI may help to diagnose optic neuropathy in pediatric patients. Periodic ophthalmologic examinations, including an OCT scan, may be useful.

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.

An Unusual Pediatric Case of Seronegative Systemic Lupus Erythematosus Presented With Acute Abdominal Pain and Gross Hematuria.

ABSTRACT: A child with acute abdomen with gross hematuria occasionally visits the emergency department (ED). Usually, such a condition is subject to differential diagnosis for stones, injuries, or sometimes malignancies in the urinary tract. Here we introduce an unusual case of a 9-year-old girl who presented to ED with acute lower abdominal pain and gross hematuria. She had no medical history. An urgent computed tomographic image revealed a renal vein thrombosis. Laboratory tests for autoimmune diseases and coagulaopathies were performed, and the results were within normal ranges. At the time, she did not fulfil the criteria for systemic lupus erythematosus or antiphospholipid syndrome. Later at follow-up, however, she had a recurrent episode of renal vein thrombosis. A kidney biopsy was performed to reveal histology of membranous lupus nephropathy. The case emphasizes the importance for both ED physicians and pediatricians to have a clinical suspicion of autoimmune diseases in cases with major vessel thrombosis, even when the patient is seronegative.

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.

Diffuse Sclerosing Variant of Papillary Thyroid Carcinoma in a Child: A Case Report.

The diffuse sclerosing variant of papillary thyroid carcinoma (DSPTC) is uncommon. Herein, we report a rare case of DSPTC in a 9-year-old girl who initially presented with a painless diffuse goiter. Thyroid peroxidase antibody testing yielded positive results, and the initial clinical diagnosis was Hashimoto's thyroiditis. However, thyroid ultrasonography revealed characteristic findings of DSPTC, which was confirmed through the postoperative histopathological diagnosis. Although thyroid cancers are rare in the pediatric population, DSPTC should be included in the differential diagnosis of goiter in these patients. Moreover, ultrasonography may prevent a diagnostic delay and facilitate the detection of a concomitant malignancy.