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J Vandevivere

Publications and source records attributed to J Vandevivere.

At least 19 recordsLinked to original sources
PubMed1999

Bone marrow content measured in radioimmune bone marrow scintigraphy: intra- and inter-observer variability.

The aim of this study was to assess the possible quantification of vertebral residual bone marrow content relative to the bone marrow content of a non-irradiated vertebra. This method is based on the vertebral count activity, measured using radioimmune bone marrow scintigraphy. First, however, we had to evaluate intra- and inter-observer variability. In three patients who underwent radioimmune bone marrow scintigraphy, two independent observers measured the count density in 51 (15 lumbar and 36 thoracic) vertebrae using a manually drawn region of interest. To evaluate intra- and inter-observer variability, we calculated the means and standard deviations of the differences between measurements. Bland-Altman plots were drawn for all vertebrae as well as for three subgroups of vertebrae (the upper thoracic spine, D1-D6; the lower thoracic spine, D7-D12; and the lumber spine, L1-L5). For all vertebrae, the mean (+/- S.D.) difference, expressed as a percentage of the overall mean, was -0.44 +/- 3.3% for observer 1 and -0.3 +/- 2.1% for observer 2 for intra-observer variability; inter-observer variability varied from 0.55 +/- 3.9% to 1.28 +/- 3.7%. On the Bland-Altman plots, the data points were evenly distributed above and below the 0-line and the linear regression equations matched the line of equality almost perfectly. This pattern was observed for all the vertebrae as well as for the subgroups of vertebrae. In conclusion, our results show that the intra- and inter-observer variabilities are not great, confirming that this technique is simple and robust and can be used for further quantification of bone marrow content in the axial skeleton.

Adult↗
PubMed1998

Nuclear cardiology, Part II: Scintigraphic evaluation of cardiac function.

OBJECTIVE: Different methods are currently available to assess cardiac function, especially left ventricular ejection fraction, using either planar or tomographic imaging, first-pass or equilibrium techniques, and blood-pool or myocardial perfusion agents. This is the second article of a four-part series on nuclear cardiology. In this article the authors review the most widely used radiopharmaceuticals and methodologies.

Coronary Circulation↗
PubMed1998

Primary cerebral lymphoma visualised by means of In-111-pentetreotide scintigraphy.

Primary lymphoma of the central nervous system, until recently representing about 1% of all brain tumours, shows a dramatically increased incidence in the general population as well as in high-risk groups (immunocompromised, AIDS), and may rise up to 6% in a population of AIDS patients. The clinical presentation is variable and cannot reliably be distinguished from other intracerebral tumours. At present, CT and MRI are the methods of choice for diagnosing cerebral lymphomas. However, their characteristics are not specific. The radiological picture may suggest glioma, meningioma, metastatic carcinoma or even a cerebrovascular accident. A labelled somatostatin analogue (pentetreotide) has been proposed as a new tracer for the imaging of somatostatin receptors, which have been identified by immunocytochemical or radioimmunoassay techniques in several organ systems. Somatostatin receptors were also identified in surgical biopsy samples from patients with Hodgkin and non-Hodgkin lymphoma and extracerebral lymphoma has already been visualised in vivo by means of In-111-labelled pentetreotide. While CT images of the brain showed a regression of the tumour after radiotherapeutic treatment, the scintigraphic images showed persistence of the tumoural tissue, corresponding with the clinical evolution and outcome. Furthermore, the absence of extra-cerebral lymphoma tissue, seen on the whole body images, was confirmed by post-mortem examination. To our knowledge, this is the first report of a primary intracerebral lymphoma visualised by means In-111-pentetreotide.

Aged↗
PubMed1997

Determination of systolic thickening index with gated Tc-99m sestamibi SPECT. A new parameter of myocardial viability?

Myocardial perfusion imaging with Tc-99m MIBI SPECT may underestimate the amount of viable myocardium in patients with coronary artery disease and prior infarction. Electrocardiogram gating could potentially better correlate with the presence of jeopardized myocardium, since it allows the evaluation of systolic contractility parameters in addition to the assessment of perfusion. Using the diastolic and systolic bull's eyes of a rest Tc-99m MIBI-gated SPECT study to generate an index of systolic thickening, we clearly observed an impaired contractility in the anterior and septal walls in a patient with multiple vessel disease and a mild mid-left anterior descending stenosis, despite a normal tracer uptake. Confirmation of the index of systolic thickening findings was obtained by rest/redistribution TI-201 SPECT, showing decreased anteroseptal perfusion on the early images with almost complete perfusion. Gating myocardial perfusion imaging seems helpful to identify myocardium at risk. It can aid in the evaluation of the physiological significance of mild coronary artery disease, sometimes insufficient to result in perceptible flow disturbances but already responsible for contractility abnormalities, especially when a large arterial territory is involved.

Aged↗
PubMed1997

Discriminative use of SPECT in frontal lobe-type dementia versus (senile) dementia of the Alzheimer's type.

UNLABELLED: Dementia of the Alzheimer's type [(S)DAT] and dementia with frontal features (FLD) are nosological entities with different prognoses and presumed pathophysiology. There is a need for noninvasive differential diagnostic tools. To evaluate whether SPECT perfusion imaging could discriminate between these neurodegenerative disorders, we performed a comparative study. METHODS: SPECT scans using 99mTc-hexamethylpropylene amine oxime (99mTc-HMPAO) of 21 patients with FLD were compared with those obtained in a group of 19 age- and severity-matched patients suffering from (S)DAT. Brain SPECT perfusion deficits were scored by visual qualitative analysis with respect to location, lateralization and severity. A total severity score of cerebral hypoperfusion (maximal value = 18) was calculated by adding all severity scores (scored between 0 and 3; 0 = no perfusion deficit; 1 = 13%-30% hypoperfusion; 2 = 30%-50%, hypoperfusion and 3 = > 50% hypoperfusion including breaching of the cortex) for right and left frontal, parietal and temporal lobes. Moreover, bifrontal hypoperfusion (Fa) was scored, yielding a value between 0 and 6 by adding the two frontal severity scores. RESULTS: No significant correlation was found between MMSE scores and total severity scores on SPECT. A statistically significant correlation was found between the Middelheim frontality score and frontal severity score. Statistically more significant bilateral hypoperfusion of the parietal lobes was found in the (S)DAT group. Conversely, bifrontal hypoperfusion was found more in the FLD group. Stepwise logistic regression analysis identified the severity of bifrontal hypoperfusion as the most significant contributing parameter to correctly classifying (S)DAT versus FLD on SPECT. The probability of predicting (S)DAT based on the SPECT scan is calculated with the following formula: [equation: see text] Using this equation, a value above 0.5 was predictive for (S)DAT and a calculated value under 0.5 was predictive for FLD. Using this model, 81% of the FLD group and 74% of the (S)DAT were correctly classified. CONCLUSION: Technetium-99m-HMPAO SPECT may help in discriminating FLD from (S)DAT. Bifrontal hypoperfusion was found to be the most powerful predictor of clinical classification. Further validation of the presented logistic regression model is warranted.

Aged↗
PubMed1996

Diagnostic value of Tc-99m sestamibi gated SPECT to assess viability in a patient after acute myocardial infarction.

The case of a 56-year-old woman who was admitted with an acute anteroseptal myocardial infarction showed severely decreased left ventricular function and regional wall motion abnormalities on planar Tc-99m gated blood pool imaging. Tc-99m sestamibi stress SPECT imaging demonstrated residual peri-infarct ischemia. At angiography, a solitary severe proximal left anterior descending stenosis was successfully dilated. Later, because of recurrent chest pain, a second Tc-99m sestamibi stress-rest SPECT was performed to exclude restenosis. Because the question of viability within the infarct region had also been asked, a gated protocol was applied and compared to TI-201 rest-redistribution SPECT. Both tests pointed to the existence of tissue viability in the septal region, without evidence for stress ischemia. The patient was then medically treated. One year later, because of angina, Tc-99m gated SPECT blood pool imaging showed a spectacular increase in left ventricular function and a dramatic improvement in regional wall motion. Angiographic data confirmed these findings and there was no significant restenosis. Thus, Tc-99m sestamibi gated SPECT may be helpful in predicting viability and recovery of function in patients with severely impaired left ventricular regional wall motion after acute myocardial infarction.

Female↗
PubMed1996

240 degrees: why not?

Single photon emission tomographic imaging of myocardial perfusion with 99Tcm-labelled agents is usually performed with single-detector gamma camera systems and 180 degrees anterior data collection. With multi-detector systems, reconstruction over 180 degrees and 360 degrees has been reported. We used a data set of normal subjects to compare both reconstruction methods. In addition, we tested an alternative approach, reconstructing data from 240 degrees acquisitions, excluding the right posterior views, which provide little myocardial information and which are responsible for a reduced signal-to-noise ratio. On the transverse slices, the known apical distortion with the 180 degrees reconstruction was not noted with the 360 degrees or 240 degrees reconstructions. Using semi-quantitative analysis of apical, mid-ventricular and basal short-axis slices, almost complete overlap was observed between the 240 degrees and 360 degrees circumferential profiles of our 20 normal volunteers, except in the inferior wall where a reduction in activity was noted. However, this finding was less pronounced with the 240 degrees than with the 180 degrees reconstruction. The frequent reduction in activity in the anterior wall was more prominent with the 180 degrees than with the 240 degrees and 360 degrees reconstructions. A 240 degrees acquisition represents a useful compromise between 180 degrees and 360 degrees imaging protocols when a single-detector device is used, allowing more homogeneous tracer distribution and a reduction in the apical distortion without material change of contrast or doubling of the acquisition time.

Adult↗
PubMed1995

Technetium-99m HMPAO SPET in acute supratentorial ischaemic infarction, expressing deficits as millilitre of zero perfusion.

A comparative interim analysis was performed of clinical parameters, computed tomographic (CT) scan results and technetium-99m hexamethylpropylene amine oxime single-photon emission tomography (SPET) findings obtained within 12 h of acute supratentorial ischaemic infarction. First, the applicability for SPET semiquantification in this study of the "method of Mountz", simultaneously accounting for extent and degrees of hypoperfusion by expressing deficits as millilitre of zero perfusion, was considered. Next, the relative contributions of perfusion SPET and CT scan in the acute stage of ischaemic infarction were compared in 27 patients (mean age 68.8 years). Finally, the correlation of SPET lesions with clinical parameters at onset was evaluated. The method of Mountz represents a workable, accurate virtual parameter, with the assumption that the contralateral brain region remains uninvolved. Interobserver reproducibility in 12 SPET studies, with lesions varying between 6 and 369 cc, showed a correlation coefficient r of 0.99. In practice, because of inconstant distribution of activities in the brain, the method can only be applied slice by slice and not on the total global volume. While the mean delay since the onset of symptomatology was approximately 7 h for both SPET and CT scan, SPET showed lesions concordant with the clinical neurological findings in 100% and CT scan in only 48%. One could hypothesize that SPET examinations performed later would show larger functional defects, because of the development of additional functional changes secondary to biochemical alterations. However, in this regard no statistically significant differences were found between two subproups, taking the median of delay before SPET examination as cut-off.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1995

Failure to label red blood cells adequately in daily practice using an in vivo method: methodological and clinical considerations.

This study was conducted to evaluate the frequency and possible causes of poor red blood cell (RBC) labelling when performing equilibrium gated blood pool (GBP) radionuclide angiography at rest with an in vivo method. The influence of the mode of administration on tagging efficiency was studied by investigating the image quality in 160 patients referred for evaluation of left ventricular (LV) function prior to or after coronary angiography, while using a roughly standardized administration protocol. The patients were subclassified into four groups according to the way both molecules involved in the tagging procedure were administered. When poor image quality was found (in 9.4% of the patients), the labelling efficiency was quantified and the frequency of failed tagging in each group was calculated. A significant association was found between poor labelling and the use of a Teflon catheter or butterfly needle for the injection of the stannous agent. In another 737 patients, in order to avoid the problems observed in the first group, a strict administration protocol was applied to analyse the frequency of poor tagging and its possible causes. Suboptimal image quality was present in 88 patients (11.9%). Quantitatively confirmed poor tagging was present in 36 of the 88 (40.9%, or 4.9% of the whole group); the remaining 52 patients showed borderline normal labelling (> 80% bound fraction). Drug interference was studied by comparing the medications used by the 36 patients showing poor binding with those used by 44 control patients. A significant relationship was found between the use of heparin or chemotherapy and the tagging. The influence of several clinical factors on the labelling was also investigated.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1995

Metastases seen on SPECT imaging despite a normal planar bone scan.

Although bone scintigraphy is an extremely sensitive method for the detection of focal bone disease, small lesions below the resolution of planar imaging may be missed. This is a report of a patient with carcinoma of the breast who showed tumor progression 1 year after initial treatment. Complete evaluation was performed in order to detect the origin of increased level of a tumor marker. Although planar bone scintigraphy could not demonstrate any lesion in the spine, multiple metastases were detected in the lumbar and the thoracic spines on SPECT imaging. Only some of these lesions were seen with MRI. Repeat planar bone imaging 6 weeks later showed multiple bone lesions in the lumbar and thoracic areas.

Adenocarcinoma↗
PubMed1992

Technetium-99m hexamethylpropylene amine oxime single photon emission tomography in febrile convulsions.

We report our initial experience with technetium-99m hexamethyl propylene amine oxime (99mTC-HMPAO) brain single photon emission tomography (SPET) in the investigation of 19 children presenting with febrile convulsions. Two patients with complex febrile convulsions showed focal SPET lesions contralateral to the neurological deficit. However, in 9 out of 17 patients with simple febrile convulsions, focally disturbed perfusion was shown. In 4 out of 6 patients with electroencephalogram (EEG) abnormalities on admittance, SPET revealed at least 2 focal lesions. The temporofrontal region was the one most commonly involved. The SPET findings presented here also suggest a temporal relationship with the febrile convulsions, with markedly fewer lesions if examined after 12 days. In our initial experience, perfusion SPET did not show any particular pattern helpful in the differential diagnosis of the child presenting with febrile convulsions. Physiopathologically, our findings may support the hypothesis that brain tissue is regionally more vulnerable to fever, in patients presenting with febrile convulsions.

Brain↗
PubMed1992

Involvement of the renal parenchyma in acute urinary tract infection: the contribution of 99mTc dimercaptosuccinic acid scan.

We performed 99mTc dimercaptosuccinic acid (DMSA) scan and ultrasonography in 146 children during the acute phase of a proven urinary tract infection (UTI). In 99 a micturating cysto-urethrography and in 83 an intravenous urography was also done. The occurrence of fever and increased WBC count, CRP and ESR were also studied. It appeared from this retrospective study that 47% of the kidneys had a cortical or patchy pattern of decreased uptake of 99mTc DMSA, as compared to 23% with abnormal findings on US. Vesico-ureteral reflux was present in 38% of the kidneys with parenchymal involvement on 99mTc DMSA scan. Although fever, leucocytosis and elevated CRP and ESR were significantly correlated with abnormal 99mTc DMSA scan, they were also observed in children without renal parenchymal involvement. Our results suggest that 99mTc DMSA scan is a sensitive method for the detection of parenchymal involvement during acute UTI. The exact nature of these lesions and their relation with scars need, however, to be defined.

Acute Disease↗
PubMed1992

Single photon emission computed tomography using perfusion tracers in seizure disorders.

Single photon emission computed tomography (SPECT) using perfusion tracers makes it possible to estimate regional cerebral blood flow (rCBF) and, indirectly, local brain metabolism. It may be possible to detect and follow physiopathological alterations, such as may be seen in seizure disorders. The authors review the principles of and some data on perfusion SPECT in seizure disorders, stress advantages as well as major drawbacks and add their initial experience with Tc-99m hexamethylpropyleneamine oxime (HMPAO) SPECT in febrile convulsions.

Humans↗
PubMed1992

Improvement in the efficacy of exercise first-pass radionuclide angiocardiography in detecting coronary artery disease and the effect of patient age.

The most widely used criterion of normality during exercise radionuclide angiocardiography (a five EF units increase in left ventricular ejection fraction from rest to exercise) has been established in young, healthy volunteers resulting in a relatively low specificity when applied to older, less fit patients or in women. In a group of 57 patients ranging in age from 22 to 79 years with a low likelihood of coronary artery disease, the age of the patient was the only independent variable predicting left ventricular ejection fraction change during exercise. The efficacy of a new age-based criterion for the diagnosis of coronary artery disease was then evaluated in 115 patients with chest pain undergoing both exercise first-pass radionuclide angiocardiography and coronary arteriography. Compared to the classic five EF unit criterion, the age-based criterion had a higher specificity (73.2% vs 34.1% P less than 0.001) without significant loss in sensitivity (85.1% vs 92.6%; P = NS).

Adult↗