Shear wave elastography and shear wave dispersion correlated to biopsy at the scheduled follow-up of pediatric liver grafts.

BACKGROUND: It is unknown how shear wave dispersion (SWD) is displayed in pediatric liver transplant recipients and not fully elucidated how ultrasound shear wave elastography (2D-SWE) display within this cohort, which is important to determine to improve noninvasive surveillance of these patients. The study aimed to compare SWE and SWD values with histopathology in pediatric liver recipients. METHODS: Forty-eight pediatric liver recipients were examined with SWE in conjunction with an elective liver biopsy (clinically without complication). Additionally, SWD values were measured in 21 children. SWE and SWD values were compared to histologically determined fibrosis graded as none-to-mild (F0-1) and moderate-to-severe (F2-4), and inflammation graded as low (grade 0-1) and high (grade 2-4). RESULTS: Two children were excluded due to SWE IQR/median > 30% kPa. The mean age across 46 included patients was 10.9 years (range 1.4-18). The number of patients and median (range) SWE value (kPa) for each stage of fibrosis were: F0-1 [n = 23; 5.8 (3.2-16.1)], F2 [n = 22; 6.0 (4.5-25.9)], F3 [n = 1; 33.3], and F4 [n = 0]. Significantly higher SWE values and greater variability were registered in F2-4 vs. F0-1 (p = .05). Grade of fibrosis correlated weakly to SWE values (r = .3; p = .05), but not to SWD values (r = .2; p = .27). In patients with low-grade inflammation, median SWD was 13.7 m/s KHz (10.7-17.6). Only one patient had high-grade inflammation. CONCLUSIONS: Uncomplicated transplanted liver grafts in a small pediatric cohort revealed slightly increased SWE and SWD values compared to previously reported values in healthy children. This likely reflect both the fibrotic and inflammatory elements in the grafts; however, other confounders impacting the liver's viscoelastic properties are also probable factors.

Transabdominal ultrasound of rectal diameter in healthy infants: a prospective cohort study during the first year of life.

AIM: Transabdominal rectal ultrasound (TRU) is used to measure transverse rectal diameter (TRD) in order to diagnose functional constipation (FC) and megarectum, and to evaluate treatment. The proposed cut-off value is 3.0 cm. Currently, no standardised values exist for children below the age of 4. We used repeated TRUs to establish reference TRD values in healthy infants and to describe rectal diameter in infants with FC. METHODS: This prospective observational cohort study enrolled healthy term babies from a maternity department. TRD measurements were taken at 2 and 12 months of age, and questionnaires completed in interviews helped diagnose FC according to Rome III criteria. RESULTS: Two hundred TRUs were performed on 110 infants (62 males). In infants without FC anytime, the mean TRD at 2 months was 1.56 (SD 0.32) cm and at 12 months 1.78 (0.47) cm, while the 95th percentiles were 2.26 and 2.64 cm, respectively. In 77 infants with two TRUs, the mean increase was 0.21 cm (95% confidence interval: 0.099-0.318). Thirteen infants were diagnosed with FC during the study period. At 2 and 12 months of age, there was no difference in TRD between infants with and without FC. CONCLUSION: TRD increased from 2 to 12 months. We suggest 2.3 cm as an upper limit for normal TRD at 2 months and 2.6 cm at 12 months. Infants diagnosed with FC did not have a greater TRD than infants without, either before or after treatment. Further studies are needed to evaluate the usefulness of TRU in infants with FC or megarectum.

Ultrasound Shear Wave Elastography, Shear Wave Dispersion and Attenuation Imaging of Pediatric Liver Disease with Histological Correlation.

Aim: To evaluate the feasibility of multiple ultrasound markers for the non-invasive characterization of fibrosis, inflammation and steatosis in the liver in pediatric patients. Materials and methods: The quantitative ultrasound measures shear wave elastography (SWE), shear wave dispersion (SWD) and attenuation imaging (ATI) were compared and correlated with percutaneous liver biopsies and corresponding measures in a control cohort. Results: The median age of the 32 patients was 12.1 years (range 0.1−17.9), and that of the 15 controls was 11.8 years (range: 2.6−16.6). Results: There was a significant difference in SWE values between histologic grades of fibrosis (p = 0.003), with a positive correlation according to the grade (r = 0.7; p < 0.0001). Overall, a difference in SWD values between grades of inflammation was found (p = 0.009) but with a lack of correlation (r = 0.1; p = 0.67). Comparing inflammation grades 0−1 (median:13.6 m/s kHz [min; max; 8.4; 17.5]) versus grades 2−3 (16.3 m/s kHz [14.6; 24.2]) showed significant differences between the groups (p = 0.003). In the 30 individuals with a steatosis score of 0, ATI was measured in 23 cases with a median value of 0.56 dB/cm/MHz. Conclusion: Comprehensive ultrasound analysis was feasible to apply in children and has the potential to reflect the various components of liver affection non-invasively. Larger studies are necessary to conclude to what extent these image-based markers can classify the grade of fibrosis, inflammation and steatosis.

Shear Wave Elastography in the Differentiation of Nonfibrotic Versus Fibrotic Liver Disease in Children: A Prospective Study With Histological Correlation.

To evaluate the diagnostic accuracy of ultrasound shear wave elastography (SWE) prospectively and to determine cutoff value for nonfibrotic liver tissue in children with suspected or established liver disease. Methods: In 90 consecutive pediatric patients, standardized 2D-SWE was performed during general anesthesia and free breathing. Liver stiffness was estimated with SWE followed by a percutaneous biopsy from the corresponding area. SWE values were compared with histology with fibrosis scored according to Batts & Ludwig classification (grade 0-4 = F0-F4) and to hepatic biomarkers. Results: Four patients with SWE interquartile range (IQR)/median ≥ 30% kPa were excluded. The remaining 86 children (59% males) had a mean age = 10.2 years (0.1-18). The distribution of individuals with median (min;max) SWE values (kPa) within each fibrosis grade were; F0[n = 10; 5.0(3.4;6.3)], F1[n = 24; 5.0(3.6;8.7)], F2[n = 32; 5.8(3.5;13.4)], F3[n = 12, 7.5(4.0;14.4)], and F4[n = 8; 12.5(6.6;21.0)]. There was a significant difference between fibrosis grades (0.03 > P < 0.002) except between F0 and F1 respectively between F1 and F2. The AuROC differentiating F0-1 from F2-4 was 0.77(95% CI: 0.67-0.87). A cutoff SWE value of ≤4.5 kPa yielded 90% sensitivity and 68% specificity to rule out significant fibrosis (F2-F4). Out of the 18 children (21%) with SWE value ≤4.5 kPa, 12 had grade F0-1 and 6 had F2, although including some confounders for increased SWE measurements as steatosis/hepatitis/cholestasis. Conclusions: 2D-SWE ultrasound can reliably distinguish no/mild (F0/F1) from moderate/severe (F2-F4) fibrosis in children with suspected/established liver disease with good sensitivity and acceptable specificity. Our results show that in pediatric patients, when the indication for biopsy is to rule out significant fibrosis, SWE can be considered an alternative.

Management of neutropenic enterocolitis in children with cancer.

AIM: To describe the symptoms, clinical management and short-term outcome in a series of paediatric oncology patients with severe typhlitis following conservative treatment. METHODS: Twelve episodes of severe typhlitis in 11 children with cancer treated at the paediatric oncology ward at Queen Silvias Children's Hospital between 1995 and 2006 were analysed retrospectively. Data on symptoms, radiological findings, laboratory status and treatment as well as outcome were collected and analysed. RESULTS: In all episodes, the classical signs of neutropenia, fever, abdominal pain and thickening of the bowel wall were present. All were successfully treated with bowel rest, broadspectrum antibiotics and supportive care. After recovery from typhlitis, three patients needed surgical intervention because of complications. CONCLUSION: A high clinical suspicion combined with radiological imaging aids early diagnosis. Predisposing factors for developing typhlitis were haematologic malignancy and treatment with chemotherapy within 3 weeks of onset. Supportive care, bowel rest including parenteral nutrition, correction of cytopenias and aggressive antimicrobial treatment is essential. Measurements of C-reactive protein in blood may be of benefit when assessing the clinical course.

An optimisation strategy in a digital environment applied to neonatal chest imaging.

The aim of this study was to find the optimum tube voltage for neonatal chest imaging in computed radiography. The study was designed to take full advantage of the benefits of digital imaging, for example, by comparing the tube voltages at constant effective dose. A phantom study using a living rabbit was first conducted. Images were collected at tube voltages ranging from 40 to 90 kV(p). The reproduction of four structures (central vessels, peripheral vessels, carina and thoracic vertebrae) was rated by 10 radiologists. The reproduction of both central and peripheral vessels was relatively independent of tube voltage. The carina was better reproduced at higher tube voltages whereas the opposite was true for the thoracic vertebrae. Based on the higher importance of the reproduction of the carina it was decided that 90 kV(p) was the optimal tube voltage. To validate the result from the phantom study, a follow-up study was conducted in which images of neonates collected at the tube voltage regularly used at Sahlgrenska University Hospital (70 kV(p)) were compared with images collected at the tube voltage proposed by the phantom study. The follow-up study confirmed the results from the phantom study that the reproduction of the carina was better at 90 than at 70 kV(p). In conclusion, for neonatal chest imaging-given the same effective dose-90 kVp gives better reproduction of important structures than the regularly used 70 kV(p).