Faculty Bibliography

PURPOSE/OBJECTIVE:This study aimed to compare the image quality of portal venous phase-derived virtual noncontrast (VNC) images from photon-counting computed tomography (PCCT) with energy-integrating dual-energy computed tomography (EI-DECT) in the same patient using quantitative and qualitative analyses. METHODS:Consecutive patients retrospectively identified with available portal venous phase-derived VNC images from both PCCT and EI-DECT were included. Patients without available VNC in picture archiving and communication system in PCCT or prior EI-DECT and non-portal venous phase acquisitions were excluded. Three fellowship-trained radiologists blinded to VNC source qualitatively assessed VNC images on a 5-point scale for overall image quality, image noise, small structure delineation, noise texture, artifacts, and degree of iodine removal. Quantitative assessment used region-of-interest measurements within the aorta at 4 standard locations, both psoas muscles, both renal cortices, spleen, retroperitoneal fat, and inferior vena cava. Attenuation (Hounsfield unit), quantitative noise (Hounsfield unit SD), contrast-to-noise ratio (CNR) (CNRvascular, CNRkidney, CNRspleen, CNRfat), signal-to-noise ratio (SNR) (SNRvascular, SNRkidney, SNRspleen, SNRfat), and radiation dose were compared between PCCT and EI-DECT with the Wilcoxon signed rank test. A P < 0.05 indicated statistical significance. RESULTS:A total of 74 patients (27 men; mean ± SD age, 63 ± 13 years) were included. Computed tomography dose index volumes for PCCT and EI-DECT were 9.2 ± 3.5 mGy and 9.4 ± 9.0 mGy, respectively (P = 0.06). Qualitatively, PCCT VNC images had better overall image quality, image noise, small structure delineation, noise texture, and fewer artifacts (all P < 0.00001). Virtual noncontrast images from PCCT had lower attenuation (all P < 0.05), noise (P = 0.006), and higher CNR (P < 0.0001-0.04). Contrast-enhanced structures had lower SNR on PCCT (P = 0.001, 0.002), reflecting greater contrast removal. The SNRfat (nonenhancing) was higher for PCCT than EI-DECT (P < 0.00001). CONCLUSIONS:Virtual noncontrast images from PCCT had improved image quality, lower noise, improved CNR and SNR compared with those derived from EI-DECT.

Though rhabdomyosarcoma is the most common soft-tissue tumor diagnosed in children there are no reported cases of prenatally detected prostatic embryonal rhabdomyosarcoma. This report demonstrates the first reported case of this phenomenon and its subsequent workup, diagnosis, and treatment.

INTRODUCTION/BACKGROUND:RENAL Nephrometry is a complexity score validated in adults with renal tumors and describes the likelihood of complication after partial nephrectomy (PN). Utilization in pediatrics has been limited. Thus, our goal is to quantify inter-rater agreement as well as determine how scores correlate with outcomes. We hypothesize that the RENAL Nephrometry Score is reproducible in children with renal tumors and is related to perioperative and post-operative complications. METHODS:All pediatric patients who underwent PN for a renal mass from 2006 to 2019 were identified. Patient data, operative details, and outcomes were aggregated. Pre-operative CT/MR imaging was anonymized and scored by 2 pediatric radiologists and 2 pediatric urologists using RENAL Nephrometry metrics. Statistical analysis utilized Fleiss' kappa and the intraclass correlation coefficient (ICC). Comparative analyses were performed based on Nephrometry Score <9 and ≥ 9. RESULTS:28 patients undergoing 33 PN were identified. Median age at surgery was 3.2 years (IQR 1.8-4.0). There is moderate-good agreement across scorers on the domains of RENAL Nephrometry Score, with the lowest agreement noted for anterior vs posterior tumors. Comparing patients with scores <9 and ≥ 9, there was increased operative time (357 vs 267 min, p = 0.003) and LOS for those with a higher score, but no difference in the incidence of 30-day complications. CONCLUSION/CONCLUSIONS:RENAL Nephrometry Score is an easily reproducible complexity score for renal tumors in pediatric patients. Higher scores are associated with increased length of stay and estimated blood loss but not complications. Reporting of nephrometry scores in future publications on pediatric renal tumors should become standard in the literature.

Beckwith-Wiedemann syndrome (BWS) is an epigenetic overgrowth disorder and cancer predisposition syndrome caused by imprinting defects of chromosome 11p15.5-11p15.4. BWS should be considered in children with atypical presentations of embryonal tumors regardless of clinical phenotype. Risk of malignancy correlates with specific molecular subgroups of BWS making molecular subclassification important for appropriate cancer screening. We report the first case of concurrent embryonal tumors in a phenotypically normal child, leading to the diagnosis of BWS with paternal uniparental disomy and describe the molecular classification of BWS as it relates to malignancy risk, along with approach to management.

Pediatric soft tissue tumors of the extremity include rhabdomyosarcoma and nonrhabdomyosarcoma neoplasms. This manuscript provides consensus-based imaging recommendations for imaging evaluation at diagnosis, during treatment, and following completion of therapy for patients with a soft tissue tumor of the extremity.

BACKGROUND:Solitary epiphyseal lesions are rare and present with nonspecific imaging features. Knowledge regarding etiologies of pediatric epiphyseal lesions is limited to small studies. OBJECTIVE:The purpose of this study was to determine the relative incidence of pathologies affecting the pediatric epiphysis based on biopsy-proven cases with imaging. MATERIALS AND METHODS/METHODS:We conducted a retrospective review of imaging studies including the terms "biopsy" or "resection" and entities known to affect the epiphysis and cross-referenced these with pathology reports, recording the relevant clinical data. Two radiologists performed comprehensive imaging review and recorded relevant features. RESULTS:Forty-nine children and adolescents met inclusion criteria. The long-bone epiphyseal lesion etiologies included chondroblastoma (n=22, 45%), nonspecific nonmalignant pathology (n=11, 22%), osteomyelitis (n=9, 18%), lymphoma (n=2, 4%) and 1 case of each of aneurysmal bone cyst, chondrosarcoma, enchondroma, hemangioendothelioma, and non-Langerhans cell histiocytosis. Median age was 13.1 years old (range 1.5-18.6 years). We performed comparative analysis of the two most common lesions in our series, chondroblastoma and osteomyelitis. Chondroblastoma was significantly more likely to be peripherally located (94% vs. 33%, P=0.002) and to demonstrate a discrete T1-weighted hypointense rim (94% vs. 33%, P=0.002); there were no significant differences in enhancement or intrinsic signal properties. Children with chondroblastoma were older (15.1 years vs. 7.3 years, P=0.001), and chondroblastoma lesions were significantly larger, with mean maximum lesion diameter of 25 mm (interquartile range [IQR] 20-30) vs. 12 mm (IQR 11-18) (P=0.001) and lesion volumes of 4.4 mL (IQR 2.4-7.9) vs. 0.4 mL (IQR 0.2-1.4) (P=0.01). CONCLUSION/CONCLUSIONS:This study reports the relative frequency of pathology of pediatric solitary epiphyseal lesions and describes several features that might assist in differentiating between chondroblastoma and osteomyelitis.

BACKGROUND:Head ultrasound (US) is commonly used to evaluate the neonatal brain but may be limited by its lack of sensitivity and specificity. Ultrasound shear wave elastography (SWE) might provide additional information to conventional gray-scale imaging. OBJECTIVE:To assess whether SWE of brain parenchyma can be (1) successfully performed at a large academic medical center where US technologists perform the majority of examinations and (2) used to detect intracranial pathology. MATERIALS AND METHODS/METHODS:Pediatric patients undergoing head ultrasound underwent simultaneous SWE examination. We included normal examinations (n=70) and those with intracranial pathology (n=8) for analysis. We analyzed inter-reader variability and examination success rates and assessed the stiffness of white matter and deep gray nuclei in normal and pathological states across multiple gestational age groups. RESULTS:Average gestational age of the term, pre-term and extreme pre-term groups were 38.4±1.2 weeks, 29.0±3.7 weeks and 28.3±3.1 weeks, respectively. Overall examination success rate was 79.5%. We observed a decrease in the SWE examination time from the first month (5.9±3.7 min) to the second month (4.1±1.7 min; P=0.01). Forty-one repeat examinations were performed on 14 children by different technologists, with an intraclass correlation coefficient (ICC) of 0.91. Mean stiffness in the periventricular white matter was lower than in the deep gray nuclei in all gestational age groups: term group (1.3 m/s vs. 1.5 m/s, P<0.001), pre-term (1.3 m/s vs. 1.4 m/s P=0.12), and extremely preterm group (1.2 m/s vs. 1.4 m/s, P=0.001). Mean stiffness for the deep gray nuclei differed between the term (1.5±0.3 m/s) and pre-term (1.4±0.2 m/s) groups (P<0.01). No significant differences in white matter stiffness were seen in relation to gestational age. Infants with large intraparenchymal hemorrhage had increased white matter stiffness (1.3±0.1 m/s) and deep gray nuclei stiffness (1.6±0.2 m/s) compared to full-term infants with normal head ultrasounds. These differences approached statistical significance with P=0.09 and P=0.06, respectively. CONCLUSION/CONCLUSIONS:We demonstrated that SWE performed by pediatric sonography technologists is reproducible. We found differences in stiffness between deep gray nuclei and periventricular white matter across multiple age groups.

OBJECTIVE. The contrast-enhanced ultrasound (CEUS) imaging features of hepatic vascular tumors in infants, including infantile hemangioma (IH) and congenital hemangioma (CH), are not well reported. Frequent inaccurate use of lesion terminology in the literature has created diagnostic confusion. The purpose of this study is to describe the CEUS features of IH and CH. MATERIALS AND METHODS. Ten patients, ranging in age from 8 days to 16 months, with hepatic vascular tumors were included for retrospective analysis. Gray-scale ultrasound, color Doppler ultrasound, and CEUS features were reviewed, and interobserver kappa coefficients were calculated. Final diagnoses were clinically determined by a pediatrician with expertise in vascular anomalies except in one patient who underwent surgical excision. RESULTS. Of the 10 patients, five had CHs and five had IHs. All 10 lesions were hyperenhancing in the early arterial phase. In the portal venous phase, four of five (80%) CHs showed hyperenhancement relative to normal liver parenchyma, whereas four of five (80%) IHs showed isoenhancement. In the late phase, washout of contrast material was seen in three of five (60%) IHs, whereas one IH remained isoenhancing and one IH was hyperenhancing. None of the CHs showed late washout. Interobserver kappa coefficients for CEUS features ranged from 0.60 to 1.00. CONCLUSION. Except for the CEUS feature portal venous phase enhancement (κ = 0.60), good to excellent (κ = 0.74-1.00) agreement about CEUS features of IHs and CHs was observed. A significant proportion of IHs (60%) showed washout at delayed phase imaging, which has also been reported with malignancies. Recognition of the overlap in imaging appearance of these two entities is vital to preventing misdiagnosis of malignancy.