Ultrasonography: Applications in Pediatric Abdomen

Ultrasound evaluation of kidney and liver involvement in Bardet-Biedl syndrome

BACKGROUND

Bardet-Biedl syndrome (BBS) is a rare autosomal-recessive ciliopathy with pathogenic variants in 26 BBS genes. It affects multiple organs, including the kidney and liver, with varying degrees regarding extent and time of first manifestation. Structural renal anomalies are an early feature and end-stage kidney disease (ESKD) cumulates to 25% in adulthood. Early-onset hyperphagia-associated obesity is another major symptom and contributes to liver pathology, presenting as steatosis/fibrosis. Aim of this study is the evaluation of high-end ultrasound (US) technologies in BBS patients regarding their potential to discriminate liver and kidney tissue pathology at an early stage.

MATERIALS AND METHODS

Patients with genetically proven BBS were recruited from the University Children's Hospital of Essen and from BBS patient days hosted in Germany. Acute illness was an exclusion criterion. Clinical and laboratory data were extracted from patients' digital records or medical letters. High-resolution ultrasound (US) imaging was utilized, including attenuation imaging (ATI), shear wave elastography (SWE) and dispersion (SWD) of liver tissue.

RESULTS

49 BBS patients (24/49 male; 1.1-51.0 years, mean 17.8 years) were included in the study. Mean body weight (SDS 2.13 ± 1.33) and BMI (SDS 2.64 ± 1.18) were increased. Structural kidney abnormalities (dysplasia, cysts) were present in 75% (36/48), and persistent fetal lobulation in 44% (21/48). Renal function was impaired in 27% (13/49) of whom 3 had ESKD (kidney transplantation (n = 2), hemodialysis (n = 1)). Elevation of liver enzymes was detected in 38% (16/42). In 51% (25/49) ATI of liver tissue was increased, indicating hepatic steatosis, and correlated with BMI SDS, liver size, and enzymes. SWE was elevated in 61% (30/49), suggesting hepatic fibrosis, and it correlated with BMI and GGT. Patients with pathogenic variants in BBS10 showed a tendency towards higher ATI, reduced GFR, and higher BMI SDS.

CONCLUSIONS

We detected kidney and liver abnormalities in a higher percentage of BBS patients than previously reported, indicating a high sensitivity and diagnostic yield of the evaluated high-end US applications. ATI detected liver pathology early (partially prior to liver enzymes) and revealed differences related to the affected genes. Evidence of tissue pathology at an early stage may improve diagnostics and the evaluation of therapeutic approaches.

Remote out-of-hours ultrasound live supervision in pediatrics - improvement of diagnostics and training

PURPOSE

Ultrasound (US) is the preferred imaging modality in pediatrics for diagnostic and therapeutic issues. The absence of radiation and the constant on-site accessibility make it the ideal tool for children. However, despite remarkable technical advances in resolution and applicability, many sophisticated medical questions still require profound expertise on the part of the examiner, thus often hampering fast decisions particularly outside regular working hours.

MATERIALS AND METHODS

This single-center study, at a university children's hospital evaluated the use of US during emergency service. A four-week documentation period was followed by a subsequent eight-week supervision period with live supervision availability on demand guided by a remote US expert. The demand for expert support, diagnosis, grading of urgency, duration and success of examination, and satisfaction of both examiners were analyzed.

RESULTS

108 patients (mean age 9.7 years) were included. In 38% of cases, US was supervised on demand with a definite diagnosis in 92.6% of cases (25/27). Image quality and technical performance were graded sufficient in 100% of cases. Supervised compared to non-supervised US examinations were prolonged (14.4 min vs. 7.1 min, p<0.001), were more prevalent within the first 24 h in the hospital (70% vs. 56.8%, p=0.06), and were classified more frequently as emergency (22.2% vs. 2.3%; p=0.015). All participants classified the availability of US supervision as decisively helpful.

CONCLUSION

Remote live supervised pediatric US was feasible and effective. It combined timely, high-quality diagnostics even in the case of challenging medical questions with simultaneous US training.

Mistakes in the ultrasound diagnostics of the abdominal cavity in pediatrics

The diagnostics of the abdominal cavity in children, especially in the neonatal-infantile period, requires knowledge in the field of anatomical and physiopathological differences as well as clinical symptomatology and pathology at every stage of the child’s development. Errors and mistakes in ultrasound diagnostics of the abdominal cavity in children result from many factors, including lack of experience in examining children and the knowledge concerning most frequent ailments and pathologies as well as the incidence or no changes in the ultrasound image of the abdominal cavity organs. The assessment of the ultrasound image should be always based on clinical data of the patient, information on the past diseases, surgeries and the results of additional examinations and laboratory tests. Particular attention should be paid to the occurrence of congenital diseases and inflammations, which may have varied clinical manifestation – especially in the case of pediatric diagnostics. The variety and non-specific nature of clinical symptoms may also mask the developing neoplastic process. Mistakes in ultrasound diagnostics, especially among the youngest children, may also be caused by technical difficulties related to carrying out the examination. The above situation results from lack of cooperation with the child, who is uneasy, wailing, fails to perform orders, which may lead to overlooking the existing lesion or overinterpreting, e.g. a full stomach or residual stool in the intestines to be a pathology. It is also of high importance to have a good class of the ultrasound equipment and technical knowledge concerning its operation. When performing an ultrasound examination in children, it is necessary to apply a wide range of phased-array, convex and linear heads and appropriate applications, the so-called pediatric software (stomach, kidneys, true pelvis, organs at the surface).

Validity of ultrasonographic measurement of gastric volume in fasted pediatric patients without sedation

Recently, gastric ultrasonography has been used as a noninvasive portable tool for evaluating gastric content and volume in adults and children. Pediatric patients are not always cooperative, especially younger ones, and it may be difficult to keep them in the appropriate scanning position without sedation. Hence, we modified the scanning method and position, and evaluated the efficacy of this alternative scanning technique in pediatric cases. We evaluated the gastric contents of 44 pediatric patients aged 4-14 years who were about to undergo elective surgery. Solid food and fluids were prohibited 8 and 2 h before anesthesia, respectively. Before anesthetic induction, we used gastric ultrasonography to measure the antral cross-sectional area in the supine position (supine CSA), irrespective of peristaltic contractions. The gastric volume was then aspirated using a multi-orifice catheter under general anesthesia. Supine CSA measured via this gastric ultrasonography method was positively correlated with gastric volume (r = 0.56, p < 0.0001). We concluded that our alternative method of measuring antral CSA may be applicable for children minimal gastric contents.