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Biomedical subjects

Rick R van Rijn

Publications and source records attributed to Rick R van Rijn.

8 recordsLinked to original sources

The sonographic characteristics of nontuberculous mycobacterial cervicofacial lymphadenitis in children.

BACKGROUND: Nontuberculous mycobacteria (NTM) are a common cause of chronic cervicofacial lymphadenitis in young children. The differential diagnosis includes other infections, lymphoepithelial cysts and malignancies. OBJECTIVE: To assess the sonographic findings of NTM cervicofacial lymphadenitis in children. MATERIALS AND METHODS: We analysed the sonograms of cervicofacial lymph nodes of 145 children with microbiologically proven NTM lymphadenitis. RESULTS: The size of the involved lymph nodes ranged from 1.9 cm to 4.4 cm. Most of the NTM patients (85%) presented in a stage of lymph node fluctuation with violaceous skin discoloration. On sonography, marked decreased echogenicity was seen in all cases. In 133 of the patients (92%) liquefaction with intranodal cystic necrosis, nodal matting and adjacent soft-tissue oedema were present. 66 children received antibiotic treatment, and the other children underwent surgical excision of the involved lymph nodes. In 69% of the patients successfully treated with antibiotics, multiple intranodal calcifications were present on sonography after 1 year. CONCLUSIONS: Sonographic findings can provide additional diagnostic clues for NTM lymphadenitis in childhood. A marked decrease of echogenicity in the early stages, with intranodal liquefaction in the advanced stages, are universal features, albeit not entirely specific. Multiple intranodal calcifications are rather characteristic of end-stage mycobacterial infection.

Anti-Bacterial Agents↗

The value of the abdominal radiograph in children with functional gastrointestinal disorders.

Functional gastrointestinal disorder is a common problem in childhood. The symptoms vary from a relative mild gastrointestinal problem such as abdominal pain or infrequent defecation to severe problems with fecal impaction and fecal incontinence. The aim of this review is to describe and evaluate the value of the different existing methods to assess fecal loading on an abdominal radiograph with or without the use of radio-opaque markers in the diagnosis of functional abdominal pain, functional constipation and functional non-retentive fecal incontinence. In our opinion, the abdominal radiograph has limited value in the diagnostic work-up of children with functional gastrointestinal disorders.

Abdominal Pain↗

Direct X-ray radiogrammetry versus dual-energy X-ray absorptiometry: assessment of bone density in children treated for acute lymphoblastic leukaemia and growth hormone deficiency.

BACKGROUND: In recent years interest in bone densitometry in children has increased. OBJECTIVE: To evaluate the clinical application of digital X-ray radiogrammetry (DXR) and compare the results with those of dual-energy X-ray absorptiometry (DXA). MATERIALS AND METHODS: A total of 41 children with acute lymphoblastic leukaemia (ALL) and 26 children with growth hormone deficiency (GHD) were included in this longitudinal study. Radiographs of the left hand were obtained and used for DXR. DXA of the total body and of the lumbar spine was performed. RESULTS: In both study populations significant correlations between DXR and DXA were found, and, with the exception of the correlation between DXR bone mineral density (DXR-BMD) and bone mineral apparent density in the GHD population, all correlations had a P-value of <0.001. During treatment a change in DXR-BMD was found in children with GHD. CONCLUSIONS: Our study showed that DXR in a paediatric population shows a strong correlation with DXA of the lumbar spine and total body and that it is able to detect a change in BMD during treatment.

Absorptiometry, Photon↗

The Leech method for diagnosing constipation: intra- and interobserver variability and accuracy.

BACKGROUND: The data concerning the value of a plain abdominal radiograph in childhood constipation are inconsistent. Recently, positive results have been reported of a new radiographic scoring system, "the Leech method", for assessing faecal loading. OBJECTIVE: To assess intra- and interobserver variability and determine diagnostic accuracy of the Leech method in identifying children with functional constipation (FC). MATERIALS AND METHODS: A total of 89 children (median age 9.8 years) with functional gastrointestinal disorders were included in the study. Based on clinical parameters, 52 fulfilled the criteria for FC, six fulfilled the criteria for functional abdominal pain (FAP), and 31 for functional non-retentive faecal incontinence (FNRFI); the latter two groups provided the controls. To assess intra- and interobserver variability of the Leech method three scorers scored the same abdominal radiograph twice. A Leech score of 9 or more was considered as suggestive of constipation. ROC analysis was used to determine the diagnostic accuracy of the Leech method in separating patients with FC from control patients. RESULTS: Significant intraobserver variability was found between two scorers (P=0.005 and P<0.0001), whereas there was no systematic difference between the two scores of the other scorer (P=0.89). The scores between scorers differed systematically and displayed large variability. The area under the ROC curve was 0.68 (95% CI 0.58-0.80), indicating poor diagnostic accuracy. CONCLUSIONS: The Leech scoring method for assessing faecal loading on a plain abdominal radiograph is of limited value in the diagnosis of FC in children.

Child↗

A longitudinal study using tibial ultrasonometry as a bone assessment technique in children with acute lymphoblastic leukaemia.

BACKGROUND: Several longitudinal studies have shown contradictory results regarding the change in bone status in children with acute lymphoblastic leukaemia (ALL) using dual-energy X-ray absorptiometry as the bone assessment technique. OBJECTIVE: To determine whether a more recently developed bone assessment technique which does not use radiation, tibial ultrasonometry, can be used for the detection of short-term changes. PATIENTS AND METHODS: From January 1997 to February 2001, 37 patients (25 boys, 12 girls, mean age 9.0 years, range 3.0-16.8 years) were included in a longitudinal study to assess changes in bone status induced by the disease itself and/or treatment. Of these 37 patients, 35 had a measurement at the start of therapy (t0), 26 at 6 months (t6), 24 at 12 months (t12), 11 at 24 months (t24) and 9 at 36 months (t36). For assessment of bone mass, the tibial ultrasound (US) device SoundScan Compact was used, which measures the speed of sound (SOS) along the cortex of the tibia over a fixed length of 5 cm at the mid-tibial point. RESULTS. The SOS standard deviation (SD) scores were significantly lower at t6, t12, t24 and t36 than at baseline (t0). The biggest change was found between t0 and t6. During follow-up, no significant correlation was found between changes from baseline of height SD scores and SOS SD scores, indicating that tibial ultrasonometry was not measuring growth. After ending therapy (t36), no further growth retardation was found. CONCLUSIONS: Short-term changes of SOS SD scores in children with ALL can be detected by tibial ultrasonometry. Tibial ultrasonometry measures a change in bone status, not growth.

Absorptiometry, Photon↗

Development of a perigraft seroma around modified Blalock-Taussig shunts: imaging evaluation.

OBJECTIVE: The modified Blalock-Taussig shunt is a synthetic shunt between the subclavian and pulmonary artery, frequently used in the treatment of children with pulmonary hypoperfusion caused by congenital heart disease. The development of a perigraft seroma is a known complication of this procedure. We sought to describe the imaging features of a perigraft seroma and to define an optimal diagnostic strategy in patients with a suspected perigraft seroma. MATERIALS AND METHODS: Between January 1993 and December 1998, 96 children underwent 105 modified Blalock-Taussig shunt procedures. In eight children, 11 cases of perigraft seromas were identified. The mean age of these children at the time of operation was 3 years (range, 6 days to 5 years 8 months). Pre- and postoperative chest radiographs were routinely performed in the children in whom seromas had been found. Additional postoperative radiologic investigations consisted of thoracic sonography (in 11 cases), CT (in eight cases), and MR imaging (in two cases). In all cases of perigraft seroma, the modified Blalock-Taussig shunts were constructed through a posterolateral thoracotomy at the fourth intercostal space. RESULTS: On average, the chest radiographs showed the first signs of the seroma on day 10 after the surgery (range, day 1-day 30). Using thoracic sonography, it was possible to visualize the perigraft seroma and the modified Blalock-Taussig shunt in eight (73%) of 11 cases. CT and MR imaging performed equally well in revealing perigraft seromas. CONCLUSION: As was found in these critically ill children, sonography has an advantage over CT and MR imaging because of its portability and, therefore, capability for bedside use. We recommend the use of sonography as the initial imaging modality in suspected cases of perigraft seroma development.

Blood Vessel Prosthesis Implantation↗