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H Ham

Publications and source records attributed to H Ham.

At least 19 recordsLinked to original sources
PubMed2006

Revisiting normal (51)Cr-ethylenediaminetetraacetic acid clearance values in children.

PURPOSE: Normal (51)Cr-ethylenediaminetetraacetic acid (EDTA) clearance values as a function of age were published a number of years ago. These values were based on data from children with a normal left to right ratio and a normal appearance on DMSA scintigraphy, despite the presence of an acute renal infection. At that time, the authors were unaware that hyperfiltration is a common phenomenon in patients with acute renal infection and that their normal values could have been significantly overestimated. The present work therefore aimed to re-appraise these normal values. METHODS: In a first step, in order to verify the previous results, the same type of population was selected, namely patients with present or past urinary tract infection but normal images and a normal left to right ratio on DMSA scintigraphy. In a second step, the selection was based on patients who had had no recent urinary tract infection. In both series, a single blood sample method was used for the evaluation of (51)Cr-EDTA clearance. RESULTS: In the first group of patients, the results obtained were almost identical to those previously published. In the second group of patients, the results were significantly lower: after 2 years of age, the mean GFR value was 104 ml/min/1.73 m(2) (10th and 90th percentiles 81 and 135 ml/min/1.73 m(2), respectively), compared with 117 ml/min/1.73 m(2) in the first group. CONCLUSION: The data of the second group are probably more representative of the true normal GFR values and can be applied to the entire paediatric population.

Adolescent↗
PubMed2005

How to interpret a deterioration of split function?

OBJECTIVE: A drop of split renal function often constitutes a criterion for pyeloplasty in hydronephrosis since it is considered as representing deterioration of the affected kidney. The aim of this work was to determine, in a selected population of patients with a drop of split function of at least 5%, if the evolution of single kidney glomerular filtration rate (SKGFR) was parallel to the one of split renal function. METHODS: From a large data basis, we found retrospectively only 29 children (10 below and 19 above two years of age at first examination) having had at least two Tc-99m mertiatide (Tc-99m MAG3) renographic explorations for various urological diseases, with a decrease of split function of at least 5% between the two examinations. Evolution of split function was compared to evolution of SKGFR obtained by means of the combination of Tc-99m MAG3 split function and overall glomerular filtration rate as given by the chromium Cr 51 ethylenediamine tetraacetic acid (EDTA) clearance. RESULTS: For the group above two years of age, SKGFR increased or remained stable in 63% of the cases, while in the children less than 2 years of age, a decrease of SKGFR was never observed, according to the maturation of overall GFR in this age group. Thus, the decrease of split function was not necessarily associated with a similar decrease of SKGFR. CONCLUSION: In patients with unilateral or bilateral urological disorders, deterioration of split renal function does not necessary correspond to a loss of function of the affected kidney. SKGFR often modifies the interpretation of split function.

Chelating Agents↗
PubMed2004

Optimised tracer-dependent dosage cards to obtain weight-independent effective doses.

PURPOSE: The aim of this study was twofold: firstly, to determine whether the European Association of Nuclear Medicine (EANM) dosage card results in weight-independent effective doses or weight-independent count rates; secondly, to determine whether one dosage card is sufficient for 95 different radiopharmaceuticals, and, if not, how many cards we reasonably need to take into account inter-tracer variability. METHODS: Normalisation factors for count rate and effective dose were calculated as a function of body weight, with 70 kg as standard. Calculations were performed, using whole-body absorption fractions and MIRDOSE 3 software, for seven anthropomorphic phantoms and ten radionuclides. An analytic function for both relations was proposed. Normalisation factors for effective dose for 95 radiopharmaceuticals were investigated using cluster analysis. RESULTS: Normalisation factors for count rate and effective dose can be estimated accurately as a function of body weight W by (W/70)a holding only one parameter, called the a value. The a values for 95 radiopharmaceuticals were classified into three clusters (nA=7, nB=76, nC=12). Cluster A contains tracers for renal studies. Cluster B contains all remaining tracers, except iodine-labelled tracers for thyroid studies and 89Sr for therapy, which belong to cluster C. CONCLUSION: Correction factors proposed by the EANM task group mainly correct for effective dose. They are very similar to the factors obtained for cluster A. Using the EANM factors for tracers belonging to clusters B and C results in significantly higher effective doses to children. We suggest using three tracer-dependent dosage cards for which the correction factors have been calculated to obtain weight-independent effective doses.

Adult↗
PubMed2004

Registration accuracy of 153Gd transmission images of the brain.

PURPOSE: The aim of the study was to determine the accuracy of non-rigid nine-parameter image registrations based on 153Gd transmission computed tomography (TCT) images as compared with those based on 99mTc-ethyl cysteinate dimer (ECD) images and to assess whether normalised mutual information (NMI) or count difference (CD) should be used. METHODS: TCT and ECD data were acquired in 25 randomly selected patients. Emission images were registered to an ECD template with a CD cost function. The same registration parameters were applied to the transmission images to create a TCT template. All TCT images were registered to the TCT template and the same registration parameters were applied to the ECD images. The procedure was repeated with NMI as cost function. Accuracy of both ECD-based and TCT-based registrations was assessed by comparing the normalisation parameter values and regional activities in the spatially normalised ECD images, using a mixed-model analysis of variance (ANOVA). Scheffe post hoc tests were performed. RESULTS: No significant differences were found between ECD/CD, ECD/NMI and TCT/CD, suggesting that ECD registration can be done with either CD or NMI, and that TCT registration using CD is equally as accurate as ECD registration. The accuracy of TCT registration with NMI was lower, with discrepancies occurring in the frontal inferior region and the cerebellum. The analysis of normalisation parameters indicated that z-scaling is underestimated and yz-rotation overestimated with TCT/NMI registration. CONCLUSION: We conclude that ECD registrations with CD or NMI are as accurate as TCT registrations with CD and that TCT registrations with NMI should be avoided.

Brain↗
PubMed2003

99mTc-MAG3 diuretic renography in children: a comparison between F0 and F+20.

The aim of this work was to compare the quality of renal drainage obtained with two well-described procedures of diuretic renography (F+20 and F0 tests). We selected 36 clinically stable children, aged 10 days to 17 years, with unilateral (25) or bilateral (11) hydronephrosis, in whom both F+20 and F0 tests were successively performed. In all cases, a late image (PM) was acquired after micturition and after changing the position of the patient. The following parameters were calculated: the time to the maximum of the basic renogram (Tmax); and the normalized residual activity (NORA) and output efficiency (OE) at the end of the 20 min renogram, at the end of the furosemide test (35 min) and on the PM image. In F+20, the renal drainage was better on the PM image than at the end of the diuretic renogram, whereas, in F0, the renal drainage was better on the PM image than at the end of the 20 min diuretic renogram. When comparing F0 and F+20, both OE and NORA parameters revealed slightly better drainage at the end of the 20 min F0 renogram than at the end of the 35 min F+20 diuretic renogram. The drainage obtained on the late post-voiding image was comparable for both F0 and F+20 tests. In conclusion, the quality of drainage obtained during the F+20 and F0 procedures can easily be compared using both OE and NORA. A very similar quality of drainage was reached for both procedures when considering only the PM image. This PM view remains mandatory irrespective of the timing of the furosemide injection and despite the use of tracers with a high extraction rate.

Adolescent↗
PubMed2003

Influence of early furosemide injection on the split renal function.

The split renal function, obtained using Technetium 99m mercaptoacetyltriglycine renography, is currently considered as a robust, accurate and reproducible parameter, provided that it is calculated at a time when no escape of the tracer from the kidney has occurred. The question arises as to whether the simultaneous administration of furosemide with the tracer (F0 test) might accelerate the escape of the tracer, resulting in an underestimation of the split renal function. From a large database, we selected 36 clinically stable children in whom both F0 and F+20 (administration of furosemide 20 min after the tracer) diuretic renography had been performed. In all cases, the F+20 test preceded the F0 test. The mean interval between the two tests was 17 months. The split renal function was calculated on the basis of the 1-2 min background-corrected renal activity using the integral method, slope method and Rutland-Patlak plot. In order to evaluate the effect on the split renal function of an early escape of the tracer, the patients were analysed according to the T(max) value of the renogram for both the F0 and F+20 tests. For the F+20 test, all T(max) values were more than 3 min. For the F0 test, the T(max) value was more than 3 min in 53 kidneys and less than 3 min in 19 kidneys (unilateral in all 19 patients). For the F0 test, for the kidneys with a T(max) value of less than 3 min, there was a tendency to underestimate the split renal function, taking as reference the split renal function observed in the F+20 test. This observation, however, was only statistically significant for the slope method (P=0.03). There was a tendency for lower values with the Rutland-Patlak plot (P=0.07), but, for the integral method, no difference was observed (P=0.5). In conclusion, the simultaneous administration of furosemide with the tracer induces an early acceleration of renal transit. This should be taken into account when calculating the split renal function, for example by favouring the integral method.

Adolescent↗
PubMed2001

A survey of physicians' attitude towards women with postmenopausal bleeding.

OBJECTIVE: To study how gynaecologist manage postmenopausal bleeding in women not using HRT. The impact on the physicians' attitude of risk factors for endometrial cancer and of the endometrial thickness was essentially accounted for. METHODS: Two different case-types were defined by modifying the risk level of developing endometrial cancer. Also the level of endometrial thickness, assessed by ultrasound, was made to vary. In total four case-types were constructed. One case-type was sent at random to each Belgian gynaecologist (n=970). RESULTS: Response rate: 55%. The proportion of physicians who would not investigate the patients' endometrium varied between 2% (high-risk patient with abnormal ultrasound) and 34% (low risk patient, normal ultrasound). Significant differences were observed in relation to the level of risk factors for endometrial cancer and in relation to endometrial thickness. No significant relationship was found between the choice of the method of endometrial investigation and the risk situation or the ultrasound result. CONCLUSIONS: The attitude of Belgian gynaecologists towards postmenopausal bleeding is modified by the presence of risk factors and by the level of endometrium thickness. About one third of physicians would not further investigate the endometrium of a patient with a low risk profile and a normal endometrium as assessed by ultrasound.

Aged↗
PubMed2001

Opinion survey towards hormone replacement therapy in the prevention of coronary heart disease.

BACKGROUND: Observational and experimental data underscore the cardioprotective effects of hormone replacement therapy (HRT). On the other hand, the randomised trial available, the 'Heart and Estrogen/Progestin Replacement Study (HERS)', showed no reduced risk of coronary heart disease (CHD), using HRT. AIM: Opinion survey on the effect of HRT on CHD risk. SETTING: Identification of articles on the related topic using a Medline search. Written survey of the authors' opinion towards HRT in relation to CHD. RESULTS: Thirty-seven of the 108 principal authors responded. Among them, respectively, 16 (43%) and seven (19%) found that HRT has favourable effects on primary and secondary prevention, two (5%) and five (14%) that it had no effect, none (0%) and four ( 11%) that it had an unfavourable effect, seven (19%) and nine (25%) that it had both favourable and unfavourable effects, and nine (25%) and ten (27%), thought that there are not enough data. Considering a risk modification superior to 20% as clinically relevant, then 57% thought that HRT has a beneficial effect of on primary prevention and 30% on secondary prevention, while none of the responders considered that HRT has unfavourable effects on primary prevention and only 2% on secondary prevention of CHD. CONCLUSION: Despite the negative results of the HERS study, about one-half of the responders still think that HRT has a beneficial effect on primary prevention of CHD and almost one-third on secondary prevention.

Attitude of Health Personnel↗
PubMed2001

Treatment of children with acute pyelonephritis: a prospective randomized study.

The aim of this study was to compare, in children with acute pyelonephritis, the efficacy of 7 days' (group A) and 3 days' (group B) intravenous antibiotics, both followed by an oral treatment. Children were randomized after 3 days of intravenous treatment. Technetium-99m dimercaptosuccinic acid (DMSA) scintigraphy was performed within the first days after admission and repeated 6 months later. Total or partial persistence of renal abnormalities on the 6-month DMSA scintigraphy was used as the endpoint of the study. Among the 92 children included in the study, 87 were followed for at least 6 months (43 in group A and 44 in group B) and were eligible for analysis. Late DMSA was abnormal in 9 kidneys of group A and 12 kidneys of group B, representing respectively 24% and 44% of kidneys with abnormalities on the initial DMSA (difference statistically not significant). When the patients were stratified according to the delay of treatment, the percentage of patients with sequelae in group A was comparable, whether the delay was less or more than 1 week. In group B, the percentage of patients with sequelae was significantly higher (P<0.01) when the delay was more than 1 week.

Acute Disease↗
PubMed2001

"Fellow gynaecologists, help your patients stop smoking!".

BACKGROUND: Age-adjusted mortality from lung cancer in American women has increased dramatically and has even exceeded breast cancer mortality. Gynaecologists, are often involved as primary actors in prevention strategies but may not be aware of this epidemic. This is especially true in Europe where, lung cancer mortality for women is three times lower than in the US. OBJECTIVE: We aimed to investigate whether smoking data could explain the lower death rates found in Europe. METHOD: Analysis of smoking and mortality data in different European countries. RESULTS: European lung cancer mortality data shows a huge heterogeneity between countries (ranging from as low as 5/100,000 to 37/100,000). A strong correlation exists between the smoking prevalence in different countries, in women aged 55 years and more, and the mortality rates from lung cancer (R(2)=0.8; p<0.001). Smoking prevalence of younger women is much higher today than that of women over 55 years. CONCLUSION: These data strongly suggest that the epidemic of lung cancer will explode in Europe during the next decades. Gynaecologists should be aware of this and spend the necessary time to inform women adequately about the dangers of smoking and help them to quit.

Europe↗
PubMed2001

Effect of physicians opinion on patients' choice of treatment.

BACKGROUND: While it is obvious that patients should be involved in the decision making process, questions arise as to whether it is feasible to inform them objectively. OBJECTIVE: To assess the impact of the physician's opinion, on the choice of treatment, to the patient. SETTING: We imagined a hypothetical case of a 55-years-old woman with a high risk of osteoporosis. Two patient information letters were written, containing valid scientific information, but reflecting two diverging physicians' opinions, giving the choice between two available medications for osteoporosis prevention: hormone replacement therapy (HRT) and a selective estrogen receptor modulator (SERM), raloxifene. SUBJECTS: We submitted one of the letters (by lottery) to 58 nurses. They were asked to act as this potential patient, and to choose which treatment they preferred to have prescribed. RESULTS: 23/30 women receiving the version favouring the use of HRT, preferred HRT, 26/28 receiving the version favouring SERM preferred this treatment (Chi-Square Pearson 37.3; P<0.001). CONCLUSION: The content of the information provided and its wording have a great influence on the patients' decision.

Estrogen Replacement Therapy↗
PubMed2001

Is deconvolution applicable to renography?

The feasibility of deconvolution depends on many factors, but the technique cannot provide accurate results if the maximal transit time (MaxTT) is longer than the duration of the acquisition. This study evaluated whether, on the basis of a 20 min renogram, it is possible to predict in which cases the MaxTT will exceed 20 min. Renograms of various shapes were simulated by convolution of a plasma disappearance curve and various created retention functions with a mean transit time (MTT) ranging from 3 to 23 min. The values of MaxTT were then derived from the created curves and compared to three parameters of transit measured on the renograms: the time to reach the maximum of the curve (Tmax), the output efficiency at 20 min (OE20), and the normalized residual activity at 20 min (NORA20). The proportion of retention functions (n=390) with MaxTT>20 min increased with increasing Tmax (e.g. 9% for 6< or =Tmax<10 min, and 34% for 11< or =Tmax<15 min), increasing NORA20 (e.g. 20% for 1.4< or =NORA20<3.0, and 84% for 3.0< or =NORA20<5.0) and decreasing OE20 (19% for 50% <OE20< or =75%, and 76% for 25% <OE20< or =50%). Use of Tmax, OE20 and NORA20 doesn't allow the differentiation of cases with a MaxTT longer or shorter than 20 min. Deconvolution can paradoxically only be used in cases of normal transit.

Humans↗
PubMed2001

Interobserver reproducibility in reporting on 99mTc-DMSA scintigraphy for detection of late renal sequelae.

UNLABELLED: This study was designed to evaluate the interobserver variability in reporting on 99mTc-dimercaptosuccinic acid (DMSA) scanning performed 6 mo after an acute episode of pyelonephritis for the detection of late renal sequelae. METHODS: Forty-six children were selected, who had early and late DMSA studies for evaluation of acute pyelonephritic lesions as well as sequelae. Three observers reported independently and separately on the early and late DMSA scans and, in a second step, on the late scan in the presence of the early scan. Interobserver reproducibility was evaluated for the early DMSA scan, the late DMSA scan alone, and the late DMSA scan with the early scan for comparison. RESULTS: Complete agreement between the three observers was reached in 75%, 78%, and 77% for the early DMSA scan, the late DMSA scan alone, and the late DMSA scan with the early scan for comparison, respectively. CONCLUSION: Interobserver reproducibility was high and was comparable for both early and late DMSA scintigraphy.

Acute Disease↗
PubMed2000

Health perception by women who work in a medical environment.

A mail survey was sent to 1154 women working in a university hospital, to assess the perception of health and the uptake of prevention strategies in an optimal setting. A list of 13 diseases was submitted and the women were asked to list the five diseases they found to be the most important for a woman of their age. Breast cancer was ranked among the five most important diseases by 85% of the women and uterus cancer by 71.3%. Other diseases, which have a high occurrence and mortality, like myocardial infarction, colon- and lung cancer were only ranked by approximately 30% of them. A high uptake of medical follow-up was reported by the surveyed women; 89% of them had seen a general practitioner or a gynaecologist during the past 12 months. Among women aged 50 and over, 92% had had at least one mammography in the past. However, only 20% had ever had faecal occult blood testing. Even among women who benefit from superior conditions for medical follow-up, the awareness of some diseases is low. Campaigns to increase awareness should consider the prevalence of diseases, their mortality and morbidity and also their actual perception in the targeted population.

Adult↗