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Biomedical subjects

S G Robben

Publications and source records attributed to S G Robben.

At least 19 recordsLinked to original sources
PubMed2001

Quantitative tibial ultrasonometry versus radiographic phalangeal absorptiometry in a Caucasian pediatric population.

There is a need for a reliable bone assessment technique in children. In this study, we compare an existing technique used in children, radiographic absorptiometry (RA), with a relatively novel technique, quantitative tibial ultrasonometry (QUS). In a prospective cohort study, we enrolled 290 girls (mean age 12.7 years) and 273 boys (mean age 12.4 years). Radiographs of the left hand and the left index finger were taken with an aluminium reference wedge within the field of exposure. Radiographic absorptiometry on the second middle phalanx at the mid-level (BMD50%) and proximal quarter (BMD25%) was performed with interactive software. Tibial QUS was performed using the SoundScan Compact. Multiple regression analysis showed that SOS correlated significantly with BMD25% for both boys (r = 0.65, P < 0.001) and girls (r = 0.59, P < 0.001), taking into account age and gender. The same applied for the correlation between speed of sound (SOS) and BMD50% in boys (r = 0.62, P < 0.001) and girls (r = 0.67, P < 0.001). Cubic regression between calendar age and BMD25% showed the best fit for both boys (r2 = 0.60) and girls (r2 = 0.60). For BMD50% a difference in regression was found between boys and girls. Quadratic regression gave a satisfactory fit for boys (r2 = 0.61 ) whereas for girls, a cubic relation was best (r2 = 0.59). Overall, there was a significant correlation between BMD25% and BMD50% for boys r = 0.89 and for girls r = 0.91 (both P < 0.001). Our data show a significant correlation between two different bone assessment techniques. In addition, these data suggest that both tibial ultrasonometry and RA are useful techniques in children.

Absorptiometry, Photon↗
PubMed2001

Is the Greulich and Pyle atlas still valid for Dutch Caucasian children today?

BACKGROUND: In our Paediatric Radiology Department, the Greulich and Pyle technique is used to assess skeletal age. Several authors have raised questions with regard to the applicability of this technique in a contemporary paediatric and adolescent population. OBJECTIVE: To compare skeletal age and calendar age in a healthy Dutch Caucasian population in order to test the applicability in this specific population. MATERIALS AND METHODS: For this study we enrolled 278 Dutch Caucasian boys (age range 5.0-19.5 years, mean 12.6 years) and 294 Dutch Caucasian girls (age range 5.2-19.9 years, mean 12.2 years). Radiographs of the left hand were scored according to the Greulich and Pyle atlas by two investigators. RESULTS: Intra-observer coefficient of variation of duplicate assessment of skeletal age for investigator 1 (resident) was 2.4 % and for investigator 2 (radiologist) was 1.5 %. We found no significant systematic differences between the two observers regarding variability and levels of measurement, and the agreement was good. There was a strongly significant correlation between skeletal and calendar age rgirls = 0.974 and rboys = 0.979 (P < 0.001). On average, calendar age preceded skeletal age by a small amount (1.7 months in girls and 3.3 months in boys, both P < 0.001). CONCLUSIONS: The reliability of the Greulich and Pyle atlas in our study corresponds well with previously reported studies. Based on our data, we conclude that the Greulich and Pyle atlas is still applicable in Dutch Caucasian children and adolescents.

Adolescent↗
PubMed2001

Early prenatal sonographic diagnosis and follow-up of Jeune syndrome.

Jeune syndrome or asphyxiating thoracic dysplasia is an autosomal recessive osteochondrodysplasia. It is one of the six short-rib (polydactyly) syndromes. The disease has a wide spectrum of manifestations, ranging from a latent to a mild or lethal condition. We describe the prenatal sonographic diagnosis of Jeune syndrome at 14 weeks of gestation in a fetus at risk for this condition, and the development of the syndrome throughout the pregnancy.

Anthropometry↗
PubMed2001

The Sophia Anatomical Infant Nose-Throat (Saint) model: a valuable tool to study aerosol deposition in infants.

Relatively little is known about the variables that influence lung deposition of inhaled aerosols in children. A model of the upper airways of an infant could be a useful tool to study these variables in vitro. The objective of this study was to construct an anatomically correct model of the upper airways of a young child. A routine three-dimensional (3D) CT scan of the skull and neck of a child was selected that included the airway from the nasal cavity down to the subglottic region. The CT scan was edited to obtain an anatomically correct distinction between air and mucosa. Next, a model was constructed with a stereolithographic technique using a UV-sensitive resin. To validate the model, a 3D CT scan of the model was made and compared to the anatomy of the original image. To study aerosol deposition, the model was connected to a breathing simulator. Medical aerosols were delivered to the model by MDI/spacer during stimulated breathing. An upper airway model was made of a 9-month-old child that needed reconstructive surgery for a skull deformity and with normal anatomy of the upper airways. The nasal airway of the model was open for air passage and the oral airway was closed. The CT scan of the model matched the original in vivo CT scan closely. Aerosol deposition measurements showed that dose passing the model, or lung dose, was comparable with in vivo lung deposition data. We have constructed an anatomically correct model of the upper airways of a child, using a stereolithographic method for in vitro studies of aerosol deposition in young children. This model will be used to obtain insight in aerosol treatment that cannot be obtained in vivo.

Aerosols↗
PubMed2001

Efficacy, safety and tolerability of 3 day azithromycin versus 10 day co-amoxiclav in the treatment of children with acute lower respiratory tract infections.

To compare the efficacy, safety and tolerability of a 3 day course of azithromycin with a 10 day course of co-amoxiclav in the treatment of children with acute lower respiratory tract infection (LRTI), 118 patients with community-acquired LRTI were included in a multicentre randomized double-blind, double-dummy study. The diagnosis of LRTI was based on the presence of respiratory signs and symptoms in combination with consolidation on a chest radiograph or clinical evidence of LRTI. Patients received oral azithromycin suspension (10 mg/kg/24 h) or placebo in one dose for 3 days and co-amoxiclav (45/11.25 mg/kg/24 h) or placebo in three doses for 10 days. Of 110 eligible patients, 56 and 54 patients, respectively, were treated with azithromycin or co-amoxiclav. The percentage of patients cured or clinically improved at days 10-13 (primary endpoint) was 91% for azithromycin and 87% for co-amoxiclav. This difference of 4% (90% confidence interval: -6%, +14%) was not statistically significant (P= 0.55). Significantly (P = 0.01) more related adverse events were found in the co-amoxiclav group. This was largely due to a higher percentage (43% versus 19%) of gastrointestinal complaints. A 3 day course of azithromycin (three doses) is as effective in the treatment of LRTI in children as a 10 day course of co-amoxiclav (30 doses). The azithromycin group had fewer adverse events. We conclude that azithromycin is an effective, safe and well-tolerated drug in the treatment of children with LRTI. An additional advantage is the easy administration and short duration of therapy.

Amoxicillin-Potassium Clavulanate Combination↗
PubMed2001

Comparison between quantitative calcaneal and tibial ultrasound in a Dutch Caucasian pediatric and adolescent population.

In the field of bone densitometry, attention has recently been focused on the pediatric population. Quantitative ultrasound (QUS) as bone assessment technique has many advantages for children in comparison with bone assessment techniques that use ionizing radiation. In this pilot study, we investigated the use of calcaneal and tibial QUS systems in a healthy Caucasian pediatric population. We studied 120 healthy Caucasian Dutch children between ages 7 and 19 yr: 53 boys (mean age of 12.5 yr, range 4.5-18) and 67 girls (mean age of 13.5 yr; range 7.1-19). We recruited children from a large population who previously had participated in a bone assessment study performed at our hospital. Two operators performed calcaneal QUS of the right calcaneus and tibial QUS of the right tibia. The correlation between calcaneal and tibial ultrasound was modest but significant (r = 0.29; p < 0.01). Using the calcaneal device, we found in girls a weak positive correlation between skeletal age and speed of sound (SOS) (r = 0.38), broadband ultrasound attenuation (r = 0.57), and quantitative ultrasound index (r = 0.46), all with a value of p < 0.01. For boys all parameters failed to reach significance. Using the tibial device, we found a good correlation between skeletal age and SOS in girls (r = 0.76) and modest correlation in boys (r = 0.50), both with a value of p < 0.01. This is one of the first studies to present a comparison between two ultrasound techniques in children. At present we feel that, in light of the poor correlation with skeletal age, calcaneal ultrasound has yet to prove its efficacy in children. Tibial ultrasound seems to be a good bone assessment technique in children.

Adolescent↗
PubMed2000

Normal values for tibial quantitative ultrasonometry in caucasian children and adolescents (aged 6 to 19 years).

Bone densitometry in children is a relatively new topic of interest within the field of osteoporosis. Bone densitometry techniques using an X-ray source have the disadvantage of radiation exposure. Also on some systems, motion artifacts are caused by long scan times. Tibial quantitative ultrasonometry (QUS) is ideally suited for children as it is radiation free and the interactive measurement provides real-time quality control. In this prospective study, we present data from 596 healthy children-309 girls, mean age 12.9 years (range 6.1-19.9), and 287 boys, mean age 12.3 years (range 6.1-19.6) from Rotterdam, The Netherlands. For all subjects, a short questionnaire regarding overall health was completed. To assess skeletal age, an X-ray of the left hand was taken and tibial QUS of the right tibia was performed using the SoundScan Compact. A statistically significant correlation was found between age and speed of sound (SOS)-r(2)(boys) = 0.52 and r(2)(girls) = 0.63 (both P < 0.001) and between skeletal age and SOS-r(2)(boys) = 0.56 and r(2)(girls) = 0. 63 (both P < 0.001). In boys, significant increase of mean SOS is seen between Tanner stages II and III and between IV and V. In girls there is a significant increase of mean SOS among all Tanner stages, except stages II and III. This is the first study to present normative tibial QUS data for Caucasian children and adolescents. In this study, normative data relative to skeletal age are also provided, facilitating the implementation of this technique in children with growth disorders showing dissociation between calendar and skeletal age.

Adolescent↗
PubMed2000

Tibial quantitative ultrasound versus whole-body and lumbar spine DXA in a Dutch pediatric and adolescent population.

RATIONALE AND OBJECTIVES: To understand normal bone development, studies in healthy children and adolescents are important. To assess the applicability of tibial quantitative ultrasound measurements (QUS) in children, we performed a study that compared dual-energy x-ray absorptiometry (DXA) of the lumbar spine and whole body with tibial QUS. METHODS: For this study we recruited 146 Dutch children and adolescents, 58 boys (median age, 14.1 years; range, 7.6-23.4 years) and 88 girls (median age, 18.0 years; range, 7.6-23.5 years). Tanner stage, weight, and height were assessed for all participants. Bone mineral density (BMD; g x cm(-2)) of the whole body and lumbar spine (L2-L4) and bone mineral apparent density (BMAD) of the lumbar spine (g x cm(-3)) were assessed by using the Lunar DPXL. For tibial QUS, the Soundscan compact system was used. RESULTS: Both lumbar as well as whole-body BMD showed a strong, significant correlation with tibial QUS in boys and girls: rtotal body boys = 0.81, rtotal body girls = 0.77, rlumbar spine boys = 0.79, and rlumbar spine girls = 0.72. Lumbar spine BMAD also showed significant correlations with tibial QUS: rboys= 0.63 and rgirls = 0.63 (for all correlations, P < 0.001). CONCLUSIONS: Our study showing strong, significant correlations between DXA and tibial QUS measurements suggests that tibial QUS is a technique that may be applicable in children and adolescents.

Absorptiometry, Photon↗
PubMed2000

Doppler sonography of the anterior ascending cervical arteries of the hip: evaluation of healthy and painful hips in children.

OBJECTIVE: We evaluated the Doppler sonography of small feeding arteries to the femoral head in children. SUBJECTS AND METHODS: In a prospective study of 224 hips in 112 patients (mean age, 5 years 11 months), the anterior ascending cervical arteries of the hip were identified with color Doppler sonography. Subsequently, we measured the resistive index (RI) with pulsed Doppler sonography. RESULTS: In 61% (137/224) of hips, a Doppler signal could be obtained. In asymptomatic hips (n = 64), the mean RI was 0.58. In symptomatic hips, the definitive diagnoses and mean values of RI included transient synovitis (n = 31) and 0.92, Perthes' disease (n = 9) and 0.67, and miscellaneous (n = 5) and 0.68. In 28 symptomatic hips, no definite diagnosis could be determined and the complaints spontaneously disappeared during follow-up (mean RI, 0.57). We found no statistically significant difference in the RI of symptomatic versus asymptomatic hips, except in patients with transient synovitis (p < 0.001). In 11 hips with transient synovitis that were reexamined after 4-6 weeks, the RI returned to normal (0.57). The RI in symptomatic hips showed a positive correlation with the amount of effusion (r = 0.69, p < 0.001). In symptomatic and asymptomatic hips, we found no correlation with age (p = 0.9 and 0.1, respectively). CONCLUSION: The deep capsular vessels of the hip joint can be evaluated on Doppler sonography in more than 60% of hips. Also, the RI is age independent and correlates with the amount of effusion.

Adolescent↗
PubMed1999

Evaluation of short-term precision for tibial ultrasonometry.

Tibial quantitative ultrasonometry is a relatively novel technique in the field of bone sonometry, an emerging alternative to bone densitometry. The implementation of this technique in a pediatric population could prove valuable from a clinical as well as a research viewpoint. In clinical practice it is necessary to know the precision of this technique and the possible influence on measurements before implementation. This study presents the precision in a Caucasian pediatric population and the influence of measurement site, dexterity, brand of coupling gel, and temperature of coupling gel. To assess intra- and interobserver variance duplicate measurements, with repositioning, ultrasonometry was performed in 10 children over a short period of time. The observers were blinded for the results of the other observer and after each measurement the skin markings were removed. Intraobserver variance for operator one (MHL) and for observer two (SFGR) was CV 0.43%. The interobserver variance was CV 0.61%. Left midtibial and right midtibial speed of sound (SOS) measurements showed no significant differences. There were, however, significant differences in both boys and girls between right proximal versus right midtibial, right midtibial versus right distal, and right proximal versus right distal (for all P < 0.001). One-way analysis of variance (ANOVA) showed that neither the use of different coupling gels nor an increase in gel temperature had a significant influence on measurements. The results of our study show that tibial quantitative ultrasonography (QUS) is a highly reproducible technique in a Caucasian pediatric population.

Adolescent↗
PubMed1999

Significance of thickening of the wall of the renal collecting system in children: an ultrasound study.

OBJECTIVE: To evaluate the significance of thickening of the wall of the renal collecting system by US. MATERIALS AND METHODS: Wall thickening of the renal collecting system was seen during US in 62 collecting systems of 51 patients over a period of 2 years. The medical and radiological records of these patients were reviewed with special attention to the definitive diagnosis and other clinical and radiological parameters. Moreover, a control group consisting of 48 renal collecting systems was examined to establish normal values for the thickness of the wall of the collecting system. RESULTS: Of the 62 collecting systems (mean wall thickness 1.6 mm, range 0.8-3.1 mm), vesicoureteric reflux (VUR) was present in 18 cases, urinary tract infection (UTI) in 11, and both VUR and UTI in 9 cases. In 10 cases, intermittent dilatation was present caused by primary obstructive megaureter (n = 2), pelvi-ureteric junction stenosis (n = 4), high-pressure bladder (n = 3), or of unknown cause (n = 1). In 11 cases, transient dilatation had been present in the recent past (usually prenatally detected hydronephrosis), but had disappeared at the time of the US examination. In 3 patients, no definite cause for the wall thickening could be established. In the control group, wall thickness ranged from 0.1 to 0.8 mm. CONCLUSIONS: The upper limit for wall thickness of the normal collecting system in children is 0.8 mm. Thickening of the wall of more than 0.8 mm should be considered as pathological and is caused by urinary tract infection, intermittent dilatation (e. g., VUR), and dilatation in the recent past.

Child↗
PubMed1999

Atrophy of the quadriceps muscle in children with a painful hip.

The objective of this study was to determine the degree of muscle wasting of various components of the quadriceps muscle in children with a painful hip. Between January 1994 and September 1997, 327 consecutive children with a unilateral painful hip and/or limping were evaluated prospectively with ultrasonography. Quadriceps thickness was measured on both sides. Moreover, muscle thickness was measured in 59 control subjects. The patients were divided into eight groups; transient synovitis (n = 134), Perthes' disease (n = 35), slipped capital femoral epiphysis (n = 5), osteomyelitis (n = 4), aspecific synovitis (n = 5), rheumatoid arthritis (n = 3) and miscellaneous (n = 16). In 125 patients, no sonographic and radiological abnormalities were found and during follow-up the symptoms disappeared ('no pathology' group). Ipsilateral muscle wasting was present in all patient groups, whereas the control subjects showed no significant difference in muscle thickness between legs. The degree of muscle wasting was compared between transient synovitis, the 'no pathology' group, Perthes' disease and control subjects. For both quadriceps and vastus intermedius muscles, there was a significant difference between these groups, except between control subjects and the 'no pathology' group. For the rectus femoris muscle, there was a significant difference between these groups, except between transient synovitis and 'no pathology'. Muscle wasting showed a positive correlation with duration of symptoms and pre-existing muscle mass. In conclusion, different diseases show different degrees of muscle wasting, and there are different patterns of muscle wasting of various components of the quadriceps femoris muscle.

Adolescent↗
PubMed1999

Anterior joint capsule of the normal hip and in children with transient synovitis: US study with anatomic and histologic correlation.

PURPOSE: To study the anatomic components of the anterior joint capsule of the normal hip and in children with transient synovitis. MATERIALS AND METHODS: Six cadaveric specimens were imaged with ultrasonography (US) with special attention to the anterior joint capsule. Subsequently, two specimens were analyzed histologically. These anatomic findings were correlated with the US findings in 58 healthy children and 105 children with unilateral transient synovitis. RESULTS: The anterior joint capsule comprises an anterior and posterior layer, mainly composed of fibrous tissue, lined by only a minute synovial membrane. Both fibrous layers were identified separately at US in 98 of 116 (84%) hips of healthy subjects and in all hips with transient synovitis. Overall, the anterior layer was thicker than the posterior layer. In transient synovitis compared with normal hips, no significant thickening of both layers was present (P = .24 and .57 for the anterior and posterior layers, respectively). Normal variants include plicae, local thickening of the capsule, and pseudodiverticula. CONCLUSION: Increased thickness of the anterior joint capsule in transient synovitis is caused entirely by effusion. There is no US evidence for additional capsule swelling or synovial hypertrophy.

Adult↗
PubMed1998

US of the painful hip in childhood: diagnostic value of cartilage thickening and muscle atrophy in the detection of Perthes disease.

PURPOSE: To evaluate the combined use of several ultrasonographic (US) criteria in the detection of Perthes disease. MATERIALS AND METHODS: In a prospective study, 144 consecutive children with a painful hip underwent US. The thicknesses of the (a) anterior recess of the joint capsule, (b) cartilage of the femoral head, and (c) quadriceps muscle were assessed. Sixty-eight children with no symptoms, the control group, were also examined. RESULTS: The final diagnosis was transient synovitis (n = 58), Perthes disease (n = 21), slipped capital femoral epiphysis (SCFE; n = 5), or miscellaneous (n = 6). Fifty-four patients had no US or radiographic abnormalities, and symptoms disappeared during follow-up. The anterior recess in patients with transient synovitis was significantly wider than that in the other patients and control subjects (P < .001). Patients with Perthes disease showed significant cartilage thickening in the symptomatic hip compared with the other patients and control subjects (P < .001). Patients with Perthes disease and patients with SCFE showed significant atrophy of the ipsilateral quadriceps muscle compared with all other groups (P < .001). The combined use of these US criteria for the diagnosis of Perthes disease resulted in a positive predictive value of 95%, a negative predictive value of 95%, a sensitivity of 71%, and a specificity of 99%. CONCLUSION: The combination of several US criteria increases the diagnostic value of US of the painful hip in patients with Perthes disease.

Adolescent↗