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C van Kuijk

Publications and source records attributed to C van Kuijk.

At least 37 records · Page 2Linked to original sources
PubMed1999

Chondrosarcoma of the foot: imaging, surgical and pathological correlation of three new cases.

The foot is an uncommon location for chondrosarcoma. The presentation, diagnosis, pathological findings, surgical treatment and follow-up of three patients with chondrosarcoma in this rare location are presented. Though nonspecific, MR imaging findings were of aid in the diagnosis and treatment planning of these patients. If the diagnosis of this tumor is rapidly made, a tumor excision instead of limb amputation may be sufficient treatment at surgery.

Adult↗
PubMed1999

Imaging of trabecular bone structure in osteoporosis.

Osteoporosis is a metabolic bone disorder that is characterized by reduced bone mass and a deterioration of bone structure which results in an increased fracture risk. Since the disease is preventable, diagnostic techniques are of major importance. Standard techniques determine bone mineral density, whereas some of the newer techniques focus on trabecular structure. This article reviews structure analysis techniques in the diagnosis of osteoporosis. Imaging techniques applied to the assessment of trabecular bone structure include conventional radiography, magnification radiography, high-resolution CT (HRCT) and high-resolution MR imaging (HRMRI). The best results were obtained using high-resolution tomographic techniques. The highest spatial resolutions in vivo were achieved using HRMRI. The most common texture analysis techniques that have been used are morphological parameters (analogous to bone histomorphometry). Fractal dimension, co-occurrence matrices, mathematical filter techniques and autocorrelation functions are more complex techniques. Most of the studies evaluating structure analysis show that texture parameters and bone mineral density both predict bone strength and osteoporotic fractures, and that combining both techniques yields the best results in the diagnosis of osteoporosis.

Bone Density↗
PubMed1998

Vertebral dimensions: influence of X-ray technique and patient size on measurements.

In this study a new reference value, "corrected vertebral dimension," is presented for vertebral height measurements. Of 68 females (age 18-88 years; mean 44.2 years) and 40 males (age 16-81 years; mean 55 years) the projected vertebral dimensions (T4-L5) were measured on lateral radiographs. In addition to this, the vertebra-to-film distances (VFD) were measured and a fixed focus-to-film distance (FFD) was used during the study. Corrected dimensions of the thoracic and lumbar vertebrae (T4-L5) were calculated using the FFD and VFD. These corrected dimensions were then used to recalculate projected vertebral dimensions at different focus-to-film distances. The applied geometric corrections were verified in a phantom study representing an in vitro situation. The results indicate that studies using different X-ray techniques for making lateral radiographs of the spine can become comparable when using corrected vertebral dimensions.

Adolescent↗
PubMed1996

Accuracy and the influence of marrow fat on quantitative CT and dual-energy X-ray absorptiometry measurements of the femoral neck in vitro.

Bone mineral measurements with quantitative computed tomography (QCT) and dual-energy X-ray absorptiometry (DXA) were compared with chemical analysis (ChA) to determine (1) the accuracy and (2) the influence of bone marrow fat. Total bone mass of 19 human femoral necks in vitro was determined with QCT and DXA before and after defatting. ChA consisted of defatting and decalcification of the femoral neck samples for determination of bone mineral mass (BmM) and amount of fat. The mean BmM was 4.49 g. Mean fat percentage was 37.2% (23.3%-48.5%). QCT, DXA and ChA before and after defatting were all highly correlated (r > 0.96, p < 0.0001). Before defatting the QCT values were on average 0.35 g less than BmM and the DXA values were on average 0.65 g less than BmM. After defatting, all bone mass values increased; QCT values were on average 0.30 g more than BmM and DXA values were 0.29 g less than BmM. It is concluded that bone mineral measurements of the femoral neck with QCT and DXA are highly correlated with the chemically determined bone mineral mass and that both techniques are influenced by the femoral fat content.

Absorptiometry, Photon↗
PubMed1995

Radiographic absorptiometry of the phalanges in healthy children and in girls with Turner syndrome.

Although bone mineral status in children has been measured with various techniques, information about development of the actual bone mass density during childhood and adolescent growth is scarce. Our modified radiographic absorptiometry (RA) determines bone mass density (BMaD) three dimensionally at the diaphyseal and metaphyseal site of the middle phalanx of the left second digit, representing predominantly cortical (50% site) and trabecular bone compartments (25% site), respectively. The objectives of this study were to establish reference curves with 95% prediction intervals of BMaD in relation to bone age (BA) during childhood and adolescence (N = 303) determined by RA. The specific effects of female puberty on BMaD were studied comparing the values of 110 untreated girls with Turner syndrome (TS) with those of the female reference group. For either sex, a piecewise linear model with one inflection point (IP) was postulated for the relationship of both the 25% and 50% site with BA. The IPs appeared at exactly the same BA (11.5 "years") for both the 25% and 50% site in boys and for the 25% site in girls. However, in girls the 50% site IP appeared 0.25 "years" later. All BMaD values to the left of the IPs showed little increase with age. In contrast, the slopes to the right of the IPs showed in both genders regression coefficients of approximately 0.05 for the 25% site. For the 50% site, the regression coefficient in girls was markedly higher (0.075) than in boys (0.058), resulting only in girls in a significant difference between the 25% and the 50% site to the right of the IP (p = 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗
PubMed1994

Course of bone mass during and after hormonal replacement therapy with and without addition of nandrolone decanoate.

A total of 33 women with postmenopausal osteoporosis were matched pairwise by age, years since menopause, and body mass index and randomized to receive either cyclic estrogen-progestagen replacement treatment (group 1) or the same treatment plus nandrolone decanoate (ND; group 2). Both groups were treated during 3 years and subsequently followed for another year off treatment. A year after cessation of the treatment the distal forearm bone mineral content in group 2 was significantly higher than that in group 1. Bone mass measurements in the axial skeleton already showed a significant difference in favor of group 2 after 3 years treatment, which persisted during the year off treatment. The decline in lumbar bone mineral mass and density in the 1 year off treatment was similar in both groups. Correction for body mass did not change these results. Bone turnover parameters did not show significant differences between the two groups after cessation of treatment. A higher muscle mass, induced by ND, could partly explain the differences between the groups since even 1 year after treatment was stopped an increased serum creatinine level was still observed in group 2.

Aged↗
PubMed1994

Skin thickness does not reflect bone mineral density in postmenopausal women.

Skin and bone both contain primarily type I collagen in connective tissue matrices and are assumed to be related due to this common organic constituent. The purpose of this study was to investigate whether skin thickness measurements by ultrasound (US) could be used for screening for low bone mass. In 94 healthy, white, non-smoking women, 1-3 years postmenopause, the thickness of the skin of the left upper arm and forearm was measured by ultrasound (US). These measurements were compared with values of bone mineral density (BMD) as measured by quantitative computed tomography (QCT) of the lumbar spine and quantitative video micro-densitometry (QMD) of the hand. The correlation found between US skin thickness measurements and BMD results was of low magnitude and not significant. It is concluded that US measurements of skin thickness cannot be used to screen early postmenopausal women for low bone mass.

Bone Density↗
PubMed1994

The association between age and bone mineral density in men and women aged 55 years and over: the Rotterdam Study.

In this cross-sectional study, bone mineral density (BMD) measurements were performed in 1762 ambulatory subjects (678 men and 1084 women) aged 55 years and over from the Rotterdam Study, a population based study of diseases in the elderly. BMD measurements of the proximal femur and lumbar spine were performed using dual energy X-ray absorptiometry. No age-related decline in BMD could be observed in the lumbar spine. Yearly percentage BMD reduction in women and men was -0.6% and -0.3% in the femoral neck, -0.8% and -0.5% in the Ward's triangle, and -0.4% and -0.3% in the trochanter, respectively. Late menopause was associated with high BMD in Ward's triangle and lumbar spine. We conclude that: (1) accurate assessment of age-related bone reduction in the spine is impossible from cross-sectional studies since BMD measurements in the elderly may be influenced by spinal osteoarthritis; and (2) the rate of age-related bone reduction in the femoral neck appears to be approximately two times higher in women than in men.

Absorptiometry, Photon↗
PubMed1993

Vertebral fracture assessment using a semiquantitative technique.

The assessment of vertebral fracture by conventional radiography has been refined and improved using either semiquantitative or quantitative criteria. The inter- and intraobserver variability was determined for a semiquantitative visual approach that we routinely use in clinical studies for assessing prevalent and incident vertebral fractures. In addition, the semiquantitative approach was compared with a quantitative morphometric approach. The incidence and prevalence of vertebral fractures were determined in 57 postmenopausal women (age 65-75 years) by three independent observers. The radiographic basis for fracture definitions and the source of interobserver agreement for the semiquantitative technique. We conclude that the semiquantitative approach can be applied reliably in vertebral fracture assessment when performed using well-defined criteria.

Aged↗
PubMed1993

Determinants of lumbar bone mineral density in normal weight, non-smoking women soon after menopause. A study using clinical data and quantitative computed tomography.

OBJECTIVES: Is there an influence of oral contraceptive use, parity and lactation on early postmenopausal bone mass? Is assessment of reproductive history, body weight in combination with biochemical markers of bone metabolism suitable to predict lumbar bone mass soon after menopause? STUDY DESIGN: A cross-sectional study in 94 healthy, normal weight, non-smoking women, 1-3 years after spontaneous menopause. Bone mineral density (BMD) of the lumbar spine was measured with single energy quantitative computed tomography. RESULTS: Multiple regression analysis showed that only total duration of lactation and alkaline phosphatase (AP) levels are independently related to trabecular BMD (P = 0.001 and P = 0.002 respectively). AP was also associated with cortical BMD (P = 0.003). Assessment of reproductive history, body mass index and biochemical markers of bone metabolism could only account for 17% of the variation of trabecular BMD observed in the study population. CONCLUSION: This study suggests that total duration of lactation rather than parity is associated with trabecular BMD of the spine. Clinical assessment of risk factors unsuccessfully predicts lumbar BMD in healthy, early postmenopausal women.

Biomarkers↗