Zero-echo time MRI: an alternative method for the diagnosis of urinary stones in children.

OBJECTIVES: To evaluate the potential of zero-echo time-magnetic resonance imaging (ZTE-MRI) in the assessment of urolithiasis and compare ZTE-MRI with computed tomography (CT) in pediatric patients. MATERIALS AND METHODS: This was a single-center, prospective cross-sectional study conducted between April 2023 and December 2023. 23 patients (12 girls, 11 boys; mean age: 12.3, range 1-18) with urinary tract stones detected on non-enhanced abdominal CT were enrolled. The images were evaluated independently by two radiologists for the presence, and number of stones in the kidneys, ureters, and bladder. In the second session, two radiologists evaluated whether urinary tract stones could be detected by MRI compared to CT, and the maximum diameter of the stones was measured. The CT and MRI results were compared with the Wilcoxon test. The agreement between the results of the observers was examined using Spearman's rho correlation coefficient and the intraclass correlation coefficient. RESULTS: A total of 58 urinary tract stones were detected by CT and 39 of these were detected by MRI. Most of the stones that MRI could not detect were < 5 mm and the detection sensitivity of MRI increased in correlation with stone size (p < 0.001). There was poor intermodality agreement for stones < 5 mm, substantial agreement for stones 5-10 mm, and almost perfect agreement for stones > 10 mm. Interobserver agreement for stone detection on MRI was almost perfect for stones > 10 mm and 5-10 mm and was substantial for stones < 5 mm. CONCLUSION: ZTE-MRI is a promising modality for detecting urinary stones without radiation exposure in children. CLINICAL RELEVANCE STATEMENT: Zero-echo time-magnetic resonance imaging is a potential method for identifying urinary stones in children and other populations who are particularly sensitive to radiation. KEY POINTS: Urinary system stone disease in children is increasing and imaging is needed for managing urolithiasis. Zero-echo time-magnetic resonance imaging (ZTE-MRI) had an accuracy of 81.8% and 93.7% for stones larger than 5 mm and 10 mm, respectively. ZTE-MRI is a potential non-irradiating method for the diagnosis and management of urolithiasis.

Radiomics in differential diagnosis of Wilms tumor and neuroblastoma with adrenal location in children.

OBJECTIVES: Machine learning methods can be applied successfully to various medical imaging tasks. Our aim with this study was to build a robust classifier using radiomics and clinical data for preoperative diagnosis of Wilms tumor (WT) or neuroblastoma (NB) in pediatric abdominal CT. MATERIAL AND METHODS: This is a single-center retrospective study approved by the Institutional Ethical Board. CT scans of consecutive patients diagnosed with WT or NB admitted to our hospital from January 2005 to December 2021 were evaluated. Three distinct datasets based on clinical centers and CT machines were curated. Robust, non-redundant, high variance, and relevant radiomics features were selected using data science methods. Clinically relevant variables were integrated into the final model. Dice score for similarity of tumor ROI, Cohen's kappa for interobserver agreement among observers, and AUC for model selection were used. RESULTS: A total of 147 patients, including 90 WT (mean age 34.78 SD: 22.06 months; 43 male) and 57 NB (mean age 23.77 SD:22.56 months; 31 male), were analyzed. After binarization at 24 months cut-off, there was no statistically significant difference between the two groups for age (p = .07) and gender (p = .54). CT clinic radiomics combined model achieved an F1 score of 0.94, 0.93 accuracy, and an AUC 0.96. CONCLUSION: In conclusion, the CT-based clinic-radiologic-radiomics combined model could noninvasively predict WT or NB preoperatively. Notably, that model correctly predicted two patients, which none of the radiologists could correctly predict. This model may serve as a noninvasive preoperative predictor of NB/WT differentiation in CT, which should be further validated in large prospective models. CLINICAL RELEVANCE STATEMENT: CT-based clinic-radiologic-radiomics combined model could noninvasively predict Wilms tumor or neuroblastoma preoperatively. KEY POINTS: • CT radiomics features can predict Wilms tumor or neuroblastoma from abdominal CT preoperatively. • Integrating clinic variables may further improve the performance of the model. • The performance of the combined model is equal to or greater than human readers, depending on the lesion size.

Imaging Features of Pediatric Sarcoidosis.

Sarcoidosis is a granulomatous inflammatory disease of uncertain cause. It occurs most commonly in young and middle-aged adults and less frequently in children; therefore, few data on pediatric sarcoidosis exist in the literature. The diagnosis and management of sarcoidosis remain challenging because of diverse and often nonspecific clinical and imaging findings. In addition, the clinical picture varies widely by age. Prepubertal and adolescent patients often present with adult-like pulmonary disease; however, early-onset sarcoidosis is typically characterized by the triad of arthritis, uveitis, and skin rash. Sarcoidosis is mostly a diagnosis of exclusion made by demonstrating noncaseating granulomas at histopathologic examination in patients with compatible clinical and radiologic findings. Although sarcoidosis often affects the lungs and thoracic lymph nodes, it can involve almost any organ in the body. The most common radiologic manifestation is pulmonary involvement, characterized by mediastinal and bilateral symmetric hilar lymphadenopathies with perilymphatic micronodules. Abdominal involvement is also common in children and often manifests as hepatomegaly, splenomegaly, and abdominal lymph node enlargement. Although neurosarcoidosis and cardiac sarcoidosis are rare, imaging is essential to the diagnosis of central nervous system and cardiac involvement because of the risky biopsy procedure and its low diagnostic yield due to focal involvement. Being familiar with the spectrum of imaging findings of sarcoidosis may aid in appropriate diagnosis and management. ©RSNA, 2023 Test Your Knowledge questions are available in the supplemental material.

Spontaneous pneumothorax in children: a radiological perspective.

BACKGROUND: Spontaneous pneumothorax is a common clinical condition due to several etiologies. Appropriate radiologic assessment helps avoid re-imaging and guide individualized management. OBJECTIVE: To describe the etiologic factors of spontaneous pneumothorax in children from a radiological perspective. MATERIALS AND METHODS: Thirty-nine children with spontaneous pneumothorax were evaluated according to their demographic characteristics, the presence of underlying lung diseases, and imaging findings. RESULTS: Twenty-one patients without underlying lung disease were assessed as primary spontaneous pneumothorax; eight of these 21 patients (38.9%) had subpleural air cysts in the apices/upper lobes of the lung on chest computed tomography (CT). In the remaining 18 patients with secondary spontaneous pneumothorax, the most common causes were respiratory diseases (33.3%), infectious lung diseases (33.3%), interstitial lung diseases (27.7%), and connective tissue diseases (5.5%). The mean age of children with secondary spontaneous pneumothorax was lower than that of children with primary spontaneous pneumothorax (P = 0.002). Recurrences occurred in 11 patients (52.3%) with primary spontaneous pneumothorax and three patients (16.6%) with secondary spontaneous pneumothorax. Bilateral pneumothorax was observed in three of the 18 patients with secondary spontaneous pneumothorax. CONCLUSION: Identifying the etiologic factors of spontaneous pneumothorax may help clinicians plan how to reduce the risk of recurrence. Radiologists should keep in mind the possible underlying diseases and assess imaging methods in children with spontaneous pneumothorax for subpleural air cysts and be suspicious about an underlying disease in cases of bilateral pneumothorax and in younger patients.

Liver magnetic resonance elastography and fat fraction in pediatric patients with cystic fibrosis versus healthy children.

BACKGROUND: Liver involvement is an important cause of morbidity and mortality in patients with cystic fibrosis (CF). While liver biopsy is the gold standard for demonstrating involvement, its invasiveness prompts a search for noninvasive alternatives. OBJECTIVE: To evaluate liver involvement in pediatric patients with CF (versus healthy controls) using magnetic resonance (MR) elastography/spectroscopy and to correlate the imaging findings with clinical/laboratory characteristics. MATERIALS AND METHODS: This was a single-center, prospective cross-sectional study conducted between April 2020 and March 2022 in patients with CF versus healthy controls. Patients with CF were divided into two subgroups: those with CF-related liver disease and those without. MR images were acquired on a 1.5-tesla machine. Kilopascal (kPa) values were derived from processing MR elastography images. MR spectroscopy was used to measure liver fat fraction, as an indication of hepatosteatosis. Groups were compared using either the Student's t test or the Mann‒Whitney U test. The chi-square test or Fisher's exact test were used to compare qualitative variables. RESULTS: Fifty-one patients with CF (12 ± 3.3 years, 32 boys) and 24 healthy volunteers (11.1 ± 2.4 years, 15 boys) were included in the study. Median liver stiffness (P=0.003) and fat fraction (P=0.03) were higher in the CF patients than in the controls. Median liver stiffness values were higher in CF patients with CF-related liver disease than in those without CF-related liver disease (P=0.002). Liver stiffness values of CF patients with high alanine aminotransferase (ALT), high gamma-glutamyl transferase, and thrombocytopenia were found to be higher than those without (P=0.004, P<0.001, P<0.001, respectively). Only the high ALT group showed a high fat fraction (P=0.002). CONCLUSIONS: Patients with CF had higher liver stiffness than the control group, and patients with CF-related liver disease had higher liver stiffness than both the CF patients without CF-related liver disease and the control group. Patients with CF had a higher fat fraction than the control group. Noninvasive assessment of liver involvement using MR elastography/spectroscopy can support the diagnosis of CF-related liver disease and the follow-up of patients with CF.

Abdominal imaging in precocious puberty in girls: can imaging determine onset of puberty?

Precocious puberty in girls is defined by the appearance of secondary sex characteristics before the age of 8 years. Precocious puberty is either peripheral or central. In most cases, the cause of central precocious puberty is unknown. Rapidly progressive forms of central precocious puberty may benefit from puberty suppression to prevent compromised final height and psychosocial problems related to the physical changes. Idiopathic central precocious puberty in girls can be a challenging diagnosis. Clinical examination, evaluation of growth charts, bone age, and hormonal tests are part of the workup. The role of pelvic ultrasound to evaluate pubertal features of the internal genitalia in this context is controversial. In this paper, we have reviewed the literature to find the scientific bases for several proposed ultrasound parameters and cutoff values for the determination of onset of puberty in girls with suspected central precocious puberty. There are no reliable cutoffs for the measurements of uterus and ovaries for the diagnosis of central precocious puberty and there is overlap in the appearance of the organs in both prepubertal and pubertal girls. The interpretation of the findings on pelvic ultrasound must be done with caution and always in close communication with the referring clinicians.

Update on imaging recommendations in paediatric uroradiology: the European Society of Paediatric Radiology workgroup session on voiding cystourethrography.

Voiding cystourethrography (VCUG) is a fluoroscopic technique that allows the assessment of the urinary tract, including the urethra, bladder, and-if vesicoureteral reflux (VUR) is present-the ureters and the pelvicalyceal systems. The technique also allows for the assessment of bladder filling and emptying, providing information on anatomical and functional aspects. VCUG is, together with contrast-enhanced voiding urosonography (VUS), still the gold standard test to diagnose VUR and it is one of the most performed fluoroscopic examinations in pediatric radiology departments. VCUG is also considered a follow-up examination after urinary tract surgery, and one of the most sensitive techniques for studying anatomy of the lower genitourinary tract in suspected anatomical malformations. The international reflux study in 1985 published the first reflux-protocol and graded VUR into five classes; over the following years, other papers have been published on this topic. In 2008, the European Society of Paediatric Radiology (ESPR) Uroradiology Task Force published the first proposed VCUG Guidelines with internal scientific society agreement. The purpose of our work is to create a detailed overview of VCUG indications, procedural recommendations, and to provide a structured final report, with the aim of updating the 2008 VCUG paper proposed by the European Society of Paediatric Radiology (ESPR). We have also compared VCUG with contrast-enhanced VUS as an emergent alternative. As a result of this work, the ESPR Urogenital Task Force strongly recommends the use of contrast-enhanced VUS as a non-radiating imaging technique whenever indicated and possible.

Pancake kidney and jejunal atresia: An uncommon dual anomaly detected prenatally-A case report.

Pancake kidney is a renal fusion anomaly with only a few reported prenatal diagnoses. Other structural anomalies beyond the urogenital system may also be associated. This study describes a dual anomaly case detected prenatally, comprising of pancake kidney and jejunal atresia. A postnatal abdominal ultrasound confirmed both kidneys were fused in the midline at the aortic bifurcation level, along with a type 3b jejunal atresia. Based on the available limited evidence about pancake kidney, renal functions appear to remain largely preserved and unaffected as in our case according to 6 months of follow-up. However, further investigation is needed to explore any potential association with chromosomal and structural abnormalities in selected cases.

A new tool supporting the diagnosis of childhood-onset Behçet's disease: venous wall thickness.

OBJECTIVES: The lower extremity venous wall thickness (VWT) of Behçet's disease (BD) patients was reported to be significantly increased in adults, suggesting its use for the support of BD diagnosis. This prospective study aimed to investigate the lower extremity VWT in childhood-onset definite and incomplete BD patients and compare it to healthy age-matched controls. METHODS: Paediatric patients classified with BD according to the 2015 international paediatric BD criteria in our centre were included in the study. Intima-media thickness of the lower extremity veins to evaluate VWT was measured by ultrasonography, including common femoral vein (CFV), femoral vein (FV), vena saphena magna, vena saphena parva and popliteal vein (PV). RESULTS: In this cross-sectional study, VWT was measured in 35 patients (63% male) and 27 healthy controls (55% male). Thirteen (37%) of 35 patients met the criteria for the diagnosis of BD. The remaining 22 (63%) had incomplete BD and met two criteria. The median VWT values of both definite and incomplete BD patients were significantly higher than the control group in all veins on both sides. Regarding the best cut-off values of VWT for all lower extremity veins, the sensitivity rates were between 63% and 86%, while specificity rates were between 71% and 100%. CONCLUSION: Increased VWT was present not only in BD patients with vascular involvement but also in those without. We suggest that VWT may be a new criterion in supporting the diagnosis of childhood BD both in definite and incomplete BD patients.

Effect of prostaglandin-E1 treatment on pyloric wall thickness in newborns with ductal-dependent critical congenital heart diseases.

BACKGROUND: Prostaglandin E1 (PGE1) is used in the medical treatment of ductal-dependent critical congenital heart disease (CCHD) in neonates. Apnea/bradycardia, hypotension, hypokalemia, and fever are the most important side effects of PGE1. Moreover, gastric outlet obstruction has been reported in a few case reports. A prospective study was conducted to investigate the effect of PGE1 treatment on pyloric wall thickness in newborns with congenital heart diseases. METHODS: A total of 22 newborns with ductal-dependent CCHD having PGE1 infusion longer than a week were included in this study. Ultrasonographic measurements were performed before and one week after the PGE1 infusion to evaluate the pyloric thickness and length. The protocol was registered with ClinicalTrials.govidentifier NCT04496050. RESULTS: A total of 22 neonates with mean gestational age 38 ± 1.8 weeks and birth weight 3105 ± 611 gr were enrolled in the study. The median time of the second ultrasound was seven days. The median cumulative dose of PGE1 given during this period was 108 mcg/kg/min. There was a statistically significant increase in post-treatment pyloric thickness and length compared to pre-treatment measurements (p < 0.001, p < 0.001). None of the patients with increased thickness and pyloric muscle length presented any symptoms. CONCLUSION: PGE1 treatment significantly increased the pyloric thickness and length after at least one-week treatment. PGE1 with its action mechanism is likely to cause gastric outlet obstruction, although not exactly pyloric stenosis on the condition used for a long time.

Beyond Wilms tumor: imaging findings and outcomes of rare renal tumors in children.

BACKGROUND: Compared to Wilms, non-Wilms renal tumors in children are less well understood due to their rare occurrence which limits precise definition of the typical imaging patterns. OBJECTIVE: This study aims to identify distinctive imaging findings, demographic characteristics and prognosis of pediatric non-Wilms renal tumors. MATERIALS AND METHODS: From January 2007 to December 2018, 207 patients with a diagnosis of primary kidney neoplasia were yielded from our radiology archive, 171 of whom were diagnosed with Wilms tumor, 4 with angiomyolipoma and one with nephrogenic rest. The remaining 31 patients with a diagnosis of primary kidney neoplasia were enrolled in this retrospective study. Imaging data, age, gender, prognosis and findings regarding follow-up were noted. RESULTS: Eight patients had renal cell carcinoma, seven had clear cell sarcoma, six had mesoblastic nephroma, four had rhabdoid tumor, three had desmoplastic small round cell tumor, two had cystic nephroma and one had metanephric stromal tumor. The age of diagnosis was > 8 years for renal cell carcinoma and desmoplastic small round cell tumor, < 5 years for rhabdoid tumor and < 7 months for mesoblastic nephroma. There was no gender preference for any tumor type. The prognosis for rhabdoid tumor was extremely poor in that all the patients followed up in our institute were deceased, whereas no recurrence was found in other tumors. Translocation type renal cell carcinoma had lower T2-weighted signal intensity, mesoblastic nephroma was a predominantly cystic mass, clear cell sarcoma was generally larger at presentation and extensive amorphous calcifications were seen in desmoplastic small round cell tumor. CONCLUSION: For the differential diagnosis of pediatric non-Wilms renal tumors, age is the most important factor, followed by propensity to metastasize/aggressive behavior of the mass. Knowledge of specific imaging findings of these tumors may help to narrow the differential diagnosis.

Radiation dose levels of thoracic-lumbar spine CT in pediatric trauma patients and assessment of scan parameters for dose optimization.

BACKGROUND: CT is frequently used for assessing spinal trauma in children. OBJECTIVE: To establish the local diagnostic reference levels of spine CT examinations in pediatric spinal trauma patients and analyze scan parameters to enable dose optimization. MATERIALS AND METHODS: In this retrospective study, we included 192 pediatric spinal trauma patients who underwent spine CT. Children were divided into two age groups: 0-10 years (group 1) and 11-17 years (group 2). Each group was subdivided into thoracic, thoracolumbar and lumbar CT groups. CT acquisition parameters (tube potential, in kilovoltage [kV]; mean tube current-time product, in milliamperes [mAs]; reference mAs; collimated slice width; tube rotation time; pitch; scan length) and radiation dose descriptors (volume CT dose index [CTDIvol] and dose-length product [DLP]) were recorded. The CTDIvol and DLP values of spine CTs obtained with different tube potential and collimated slice width values were compared for each group. RESULTS: CTDIvol and DLP values of thoracolumbar spine CTs in group 1 and lumbar spine CTs in group 2 were significantly lower in CTs acquired with low tube potential levels (P<0.05). CTDIvol and DLP values of thoracolumbar spine CTs in both groups and lumbar spine CTs in group 2 acquired with high collimated slice width values were significantly lower than in corresponding CTs acquired with low collimated slice width values (P<0.05). CONCLUSION: Pediatric spine CT radiation doses can be notably reduced from the manufacturers' default protocols while preserving image quality.

Magnetic resonance imaging of pulmonary infection in immunocompromised children: comparison with multidetector computed tomography.

BACKGROUND: Computed tomography (CT) is commonly used to detect pulmonary infection in immunocompromised children. OBJECTIVE: To compare MRI and multidetector CT findings of pulmonary abnormalities in immunocompromised children. MATERIALS AND METHODS: Seventeen neutropaenic children (6 girls; ages 2-18 years) were included. Non-contrast-enhanced CT was performed with a 64-detector CT scanner. Axial and coronal non-enhanced thoracic MRI was performed using a 1.5-T scanner within 24 h of the CT examination (true fast imaging with steady-state free precession, fat-saturated T2-weighted turbo spin echo with motion correction, T2-weighted half-Fourier single-shot turbo spin echo [HASTE], fat-saturated T1-weighted spoiled gradient echo). Pulmonary abnormalities (nodules, consolidations, ground glass opacities, atelectasis, pleural effusion and lymph nodes) were evaluated and compared among MRI sequences and between MRI and CT. The relationship between MRI sequences and nodule sizes was examined by chi- square test. RESULTS: Of 256 CT lesions, 207 (81%, 95% confidence interval [CI] 76-85%) were detected at MRI. Of 202 CT-detected nodules, 157 (78%, 95% CI 71-83%) were seen at motion-corrected MRI. Of the 1-5-mm nodules, 69% were detected by motion-corrected T2-weighted MRI and 38% by HASTE MRI. CONCLUSION: Sensitivity of MRI (both axial fat-saturated T2-weighted turbo spin echo with variable phase encoding directions (BLADE) images and HASTE sequences) to detect pulmonary abnormalities is promising.

Imaging Findings of Fetal-Neonatal Ovarian Cysts Complicated With Ovarian Torsion and Autoamputation.

OBJECTIVE: Large nonresolving neonatal ovarian cysts may be a risk factor for complications such as torsion, mass effect, rupture, intracystic hemorrhage, and autoamputation. Torsed cysts and autoamputated cysts can cause a diagnostic dilemma. The objective of our study was to correlate the imaging findings of intrauterine ovarian torsion and autoamputated ovaries with their pathologic findings. MATERIALS AND METHODS: We retrospectively analyzed the pre- and postnatal medical records, sonographic findings, operation notes, and pathologic reports of 15 patients with ovarian torsion. All patients had complex cysts noted on postnatal sonographic examination. A complex heterogeneous ovarian cyst was defined by the presence of a fluid-debris level indicating hemorrhage within the cyst, a retracting clot, septations with or without internal echoes, calcification, and a solid component. RESULTS: On ultrasound examination, four cysts had solid components, and 11 were heterogeneous and had a fluid-debris level. Calcifications were seen in two patients. The mean patient age at the time of surgery was 3.9 months. Exploratory laparotomy was performed on all patients. Torsed ovaries were identified in five patients. Ten patients had ovaries that were floating free in the peritoneal cavity at the time of surgery. Histopathologic evaluation revealed that 11 of the cysts consisted of extensive hemorrhagic, necrotic autolytic tissue with dystrophic calcification. None of the cysts contained any ovarian tissue. CONCLUSION: A complex heterogeneous ovarian cyst with a fluid-debris level indicating hemorrhage is a significant sonographic hallmark for the diagnosis of ovarian torsion. A calcified abdominal mass, with or without wandering, can be an autoamputated ovary.

Imaging findings of pediatric rheumatologic emergencies.

OBJECTIVE. Pediatric rheumatologic diseases can present with a wide spectrum of clinical features, affecting any organ in the body and causing significant morbidity and mortality. The aim of this review is to emphasize the diagnostic imaging findings of pediatric rheumatologic emergencies and to discuss their pertinent complications. CONCLUSION. Because of their multiorgan and multisystem involvement, pediatric rheumatologic diseases comprise a wide spectrum of differential diagnosis. Although the diagnosis may generally not be time critical, for a few conditions, prompt recognition is crucial to preserving organ function or the patient's life [ 1 ].

Pneumomediastinum, pneumorrhachis and subcutaneous emphysema associated with viral infections: Report of three cases.

Spontaneous pneumomediastinum is usually secondary to alveolar rupture in the pulmonary interstitium, associated with subcutaneous emphysema and occasionally with pneumothorax, but is rarely associated with pneumorrhachis. The leaked air into the pulmonary perivascular interstitium follows the path of least resistance from the mediastinum to the fascial planes of the neck. Air freely communicates via the neural foramina and collects in the epidural space. Pneumorrhachis is defined as the presence of air in the spinal canal, either in the intradural and/or extradural spaces. It is a very rare clinical entity and mostly asymptomatic, hence most probably underdiagnosed. Many pathological and physiological events can lead to alveolar rupture, and these clinical findings can be related to various, mainly traumatic and iatrogenic etiologies. Herein we report three cases of pneumomediastinum, subcutaneous emphysema, interstitial emphysema and pneumorrhachis in two cases, which were related to rhinovirus, human bocavirus and respiratory syncytial virus infection.

Intraosseous pseudotumor in a child with hypofibrinogenemia.

Intraosseous pseudotumor (i.e. chronic, encapsulated, hemorrhagic fluid collection that can be seen in any portion of the tubular bones) is an uncommon complication of severe hemophilia; however, it can occur with other rare bleeding disorders. We present the case of an 11-year-old girl with hypofibrinogenemia who had multiple intramedullary lesions that were consistent with intramedullary pseudotumor associated with this rare bleeding disorder. Percutaneous biopsy of a pseudotumor is contraindicated due to the high prevalence of complications, including life-threatening bleeding. Therefore, radiologists should make the diagnosis with characteristic MR imaging findings in a patient with a severe coagulation disorder.

Focal fatty sparing areas of the pediatric steatotic liver: pseudolesions on hepatobiliary phase magnetic resonance images.

PURPOSE: Focal fatty sparing in liver can be detected as hyperintense pseudolesions on hepatobiliary phase magnetic resonance imaging (MRI). Distinguishing these pseudolesions from liver lesions may make diagnosis challenging. The aim of this study was to evaluate the imaging features of fatty sparing areas on liver MRI in pediatric patients who have been administered gadoxetate disodium. METHODS: A total of 63 patients between January 2018 and June 2023 underwent gadoxetate disodium-enhanced liver MRI, and 9 (14%) patients with a focal fatty sparing were included in the study. The fat spared areas were evaluated qualitatively and quantitatively including signal intensity measurements and fat fraction calculations. RESULTS: The liver MRI examinations of 9 patients (5 boys, 4 girls; aged 8-18 years, median age: 14.4) using gadoxetate disodium were evaluated. Based on in-phase and opposed-phase sequences, 13 areas of focal fatty sparing were identified. The mean fat fraction of the liver and fat spared areas were 26.2% (range, 15-47) and 9% (range, 2-17), respectively. All fat spared areas were hyperintense in the hepatobiliary phase images. The mean relative enhancement ratios of the liver and fat spared areas were 0.78 (range, 0.35-1.6) and 1.11 (range, 0.45-1.9), respectively. CONCLUSION: Focal fatty sparing in liver in children was observed as hyperintense on hepatobiliary phase MRI, and it should not be identified as a focal liver lesion.