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P De Coster

Publications and source records attributed to P De Coster.

16 recordsLinked to original sources
PubMed2002

Is a lung perfusion scan obtained by using single photon emission computed tomography able to improve the radionuclide diagnosis of pulmonary embolism?

Planar pulmonary scintigraphy is still regularly performed for the evaluation of pulmonary embolism (PE). However, only about 50-80% of cases can be resolved by this approach. This study evaluates the ability of tomographic acquisition (single photon emission computed tomography, SPECT) of the perfusion scan to improve the radionuclide diagnosis of PE. One hundred and fourteen consecutive patients with a suspicion of PE underwent planar and SPECT lung perfusion scans as well as planar ventilation scans. The final diagnosis was obtained by using an algorithm, including D-dimer measurement, leg ultrasonography, a V/Q scan and chest spiral computed tomography, as well as the patient outcome. A planar perfusion scan was considered positive for PE in the presence of one or more wedge shaped defect, while SPECT was considered positive with one or more wedge shaped defect with sharp borders, three-plane visualization, whatever the photopenia. A definite diagnosis was achieved in 70 patients. After exclusion of four 'non-diagnostic' SPECT images, the prevalence of PE was 23% (n =15). Intraobserver and interobserver reproducibilities were 91%/94% and 79%/88% for planar/SPECT images, respectively. The sensitivities for PE diagnosis were similar for planar and SPECT perfusion scans (80%), whereas SPECT had a higher specificity (96% vs 78%; P =0.01). SPECT correctly classified 8/9 intermediate and 31/32 low probability V/Q scans as negative. It is concluded that lung perfusion SPECT is readily performed and reproducible. A negative study eliminates the need for a combined V/Q study and most of the 'non-diagnostic' V/Q probabilities can be solved with a perfusion image obtained by using tomography.

Adult↗
PubMed1998

Mechanisms of acute eosinophilic inflammation in a case of acute eosinophilic pneumonia in a 14-year-old girl.

BACKGROUND: Acute eosinophilic pneumonia (AEP) is characterized by respiratory distress, eosinophilic infiltration in the lung, acute onset, resolution of symptoms with corticosteroids and the absence of relapse. Studies to identify the pathophysiology of AEP in adults have demonstrated eosinophil activation in the BAL fluid, and the presence of high levels of interleukin 5 (IL-5) in the BAL. OBJECTIVE: To investigate the pathophysiology of AEP with pleural effusion in a paediatric patient. METHODS: ECP levels in the BALand pleural fluid was determined by radioimmunoassay. IL-5 and GM-CSF concentrations in the BAL and pleural fluid were measured by Elisa. Immunohistochemistry studies performed on open lung biopsy included a specific ICAM-1 immunostaining and a ECP specific immunostaining (EG2+). RESULTS: High levels of ECP were found in the BAL (5 microg/L) and pleural fluid (750 microg/L) demonstrating eosinophil activation at these sites. Immunohistochemistry illustrated activated (EG2+) eosinophils in the interalveolar septa and alveolar space and detected increased expression of ICAM-1 on alveolar epithelial cells. High levels of IL-5 were measured in the BAL (1334 pg/mL) and pleural fluid (7014 pg/mL), while elevated concentrations of GM-CSF (150 pg/mL) were found in the BAL. CONCLUSION: We conclude that in this paediatric patient with AEP activated eosinophils were present in the BAL fluid, in the interalveolar septa and in the pleural space while increased ICAM-1 expression was detected on alveolar epithelial cells, contributing, at least partly, for their adhesive interactions. IL-5 and GM-CSF are likely important to the massive eosinophil recruitment and activation in the lung, while IL-5 is probably related to eosinophil accumulation and activation in the pleural space. Thus, lung generation of eosinophil-active cytokines is central to the pathophysiology of AEP in paediatric patients.

Acute Disease↗
PubMed1996

Persisting perfusion defect in transient ischemic attacks: a new clinically useful subgroup?

BACKGROUND AND PURPOSE: Cerebral infarction and prolonged regional hypoperfusion have been described in patients with transient ischemic attacks (TIAs). The aim of this study was to compare the sensitivity of single-photon emission CT (SPECT) with that of brain CT and to evaluate the clinical significance of differentiation of TIA patients with or without focal hypoperfusion. METHODS: From a hospital-based population, we studied the SPECT and CT findings in 76 consecutive patients, without a stroke history, who presented with TIA in the carotid artery territory. The recorded variables were the time of SPECT, imaging (<36 or > or = 36 hours), clinical presentation, history of previous TIA(s), duration of the presenting attack (<2 or > or = 2 hours), vascular risk factors, and etiology. We used both visual and semiquantitative analyses for the SPECT evaluation. Acetazolamide challenge was not performed. RESULTS: The overall SPECT sensitivity was 36% (27/76). When brain CT and SPECT were performed in the same patients, the SPECT sensitivity was significantly higher than that of CT (19/59 [32%] versus 8/59 [14%]; P=.007). The SPECT sensitivity was not dependent on the time of investigation, duration of attacks, history of TIA(s), or the clinical presentation. The vascular risk and etiologic factors were not significantly different between the patients with or without prolonged focal hypoperfusion. Logistic regression did not identify any variable to discriminate the two groups. CONCLUSIONS: Despite its better sensitivity compared with CT, SPECT performed without the acetazolamide test provides no additional clinically useful information on the vascular risk factors and etiology in TIA patients.

Acetazolamide↗
PubMed1995

Exercise gated planar myocardial perfusion imaging using technetium-99m sestamibi for the diagnosis of coronary artery disease: an alternative to exercise tomographic imaging.

Single-photon emission tomography (SPET) using technetium-99m labelled myocardial tracers (e.g. 99mTc-sestamibi) has become one of the most popular myocardial imaging methods for the diagnosis of coronary artery disease (CAD). This prospective study was designed to evaluate the diagnostic performance of 99mTc-sestamibi exercise gated planar myocardial imaging by comparison with both visual and quantitative analyses of SPET. The study was conducted in 115 consecutive patients with known or suspected CAD, including 54 patients with a previous myocardial infarction (MI), referred for exercise testing prior to coronary angiography. Multi-gated planar imaging and SPET were performed after bicycle exercise. The end-diastolic (ED) and SPET images were visually scored (SVi). Myocardial uptake was quantitated on SPET slices using maximum count circumferential profiles (SQu) and defect extent was measured by comparison with gender-matched data sets obtained from 27 controls (< 5% likelihood of CAD). CAD was defined as coronary artery stenosis > 50% and/or regional wall motion abnormality. The cut-off criteria for positivity of the three procedures were determined from receiver operating characteristic (ROC) curves derived from the data of patients without previous MI. The area under the ROC curves was similar for ED, SVi and SQu. This was confirmed by the analysis of sensitivity performed using the ROC curve-derived cut-off criteria, in patients with or without previous MI. SVi was more sensitive than ED in identifying the diseased vessel(s) (ED: 41% vs SVi: 80%; P < 0.0005) but ED was more specific in this respect (ED: 79% vs SVi: 61%; P < 0.0005).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

HMPAO single-photon emission computed tomography in posterior circulation infarcts.

The sensitivity of single-photon emission computed tomography (SPECT) in evaluating posterior circulation infarcts compared with that of computed tomography (CT) or magnetic resonance imaging (MRI) remains unknown. In a hospital-based population, the authors studied SPECT, CT, and MRI in 35 consecutive patients presenting with acute infarction clinically localized in the thalamus (7), posterior cerebral artery (PCA) territory (15), brainstem (19), and cerebellum (3). Multiple infarcts were noted in 8 patients. Overall, the SPECT sensitivity was lower than that of MRI (21% vs 93%, p = 0.004) and CT (42% vs 65%, p = 0.046). The SPECT and CT sensitivities were not significantly different (67% vs 73%) for PCA infarcts. Performed within 24 hours, SPECT showed a relevant hypoperfusion in all PCA infarcts. For brainstem infarcts, CT (33%, p = 0.074) and MRI (91%, p = 0.004) were more sensitive than SPECT, which showed no hemispheric hypoperfusion. The sensitivity of the three imaging techniques was 100% for large cerebellar infarcts. For the small group of thalamic infarcts, the SPECT, CT, and MRI sensitivities were 14, 71, and 100%, respectively. Thus, SPECT compared to CT and MRI is not helpful in the subacute phase to localize PCA and cerebellar infarcts and is of limited value for thalamic infarcts. In the first hours, the absence of cerebral hypoperfusion in brainstem infarcts may help to differentiate them from hemispheric infarcts usually associated with profound hypoperfusion.

Aged↗
PubMed1995

Comparative correlations of HMPAO SPECT indices, neurological score, and stroke subtypes with clinical outcome in acute carotid infarcts.

BACKGROUND AND PURPOSE: The prognostic value of single-photon emission computed tomography (SPECT) remains controversial. The aim of this study was to compare the prognostic value of stroke severity, stroke subtypes, and SPECT indices and to determine which predictive factors have an independent effect on clinical outcome. METHODS: We studied 55 consecutive patients with acute (< 12 hours) carotid infarct within 36 hours of symptom onset with SPECT. Clinical presentation was assessed by the Canadian Neurological Scale and stroke subtypes. SPECT indices were the degree and size of hypoperfusion and crossed cerebellar diaschisis as assessed by a semiquantitative analysis. Outcome was evaluated by the functional status and mortality (Rankin Scale score at 1 month). RESULTS: The Rankin Scale score correlated with the degree (r = .580; P < .00001) and size (r = .616; P < .00001) of hypoperfusion. The mean degree and size of hypoperfusion were significantly higher in patients with poor outcome. Crossed cerebellar diaschisis had no significant predictive value. Statistical analysis determined threshold values for the Canadian Neurological Scale score and the degree and size of hypoperfusion for the functional status and mortality. The degree and size of hypoperfusion had no higher performance than the Canadian Neurological Scale score. The negative predictive value was excellent for both clinical and SPECT indices. Multivariate analysis selected only the size of hypoperfusion as an independent predictor for the functional status (P = .004) and the Canadian Neurological Scale score for mortality (P = .009). CONCLUSIONS: SPECT performed within 36 hours of onset predicts clinical outcome, but different clinical and SPECT indices with threshold values should be chosen according to the relevant outcome end point.

Aged↗
PubMed1995

Cerebral blood flow and perfusion reserve capacity in hemodynamic carotid transient ischemic attacks due to innominate artery stenosis.

Ischemia in the carotid artery territory due to atherosclerotic stenosis of the innominate artery is rare. We report a case in which transcranial Doppler ultrasonography (TCD) and SPECT with acetazolamide challenge proved the hemodynamic mechanism. The patient presented with three hypotensive TIAs in the right middle cerebral artery territory. Angiography showed a tight innominate artery stenosis and subclavian steal but no coexistent carotid or vertebrobasilar lesion. SPECT showed disturbed regional blood flow in the middle cerebral artery territory along with an exhausted perfusion reserve capacity. After angioplasty, flow velocities were normal and the perfusion reserve was restored. SPECT should be used to select patients at risk susceptible to benefit from angioplasty.

Adult↗
PubMed1994

[Status of 3 years of hyperthyroidism treatment with iodine 131].

We analysed retrospectively the results obtained during 3 years in the treatment of thyrotoxicosis with 131-iodine. A group of 32 patients, including 21 Graves' diseases, 10 multinodular toxic goitres and 1 toxic adenoma has been collected. The therapeutic efficacy of one dose of radioiodine, assessed after 6 months was 100% in toxic multinodular goitres and 57% in Graves' diseases. No acute complications were observed. The best radiosensitivity of toxic multinodular goitres compared with diffuse goitres is probably due to the mechanisms themselves of thyrotoxicosis in these diseases. Results also suggest that multinodular toxic goitres in our country should be systematically treated with antithyroid drugs before radioiodine. In Graves' disease, no predictive factor of the early response to therapy could be definitely evidenced. Finally, clinicians should be aware of the advantages of such a treatment of thyrotoxicosis which is not very aggressive and at least definitive.

Adult↗
PubMed1991

Comparison between the positive inotropic effects of enoximone, a cardiac phosphodiesterase III inhibitor, and dobutamine in patients with moderate to severe congestive heart failure. A study using the end-systolic pressure-volume relationship method.

This study was designed to compare the positive inotropic properties of enoximone, a cardiac phosphodiesterase III inhibitor, with those of dobutamine in a population of moderate to severe congestive heart failure patients. The end-systolic pressure-volume relationship method was used. In addition, the haemodynamic effects of both drugs were compared. In seven of the 11 patients studied, enoximone induced a significant shift upwards and to the left of the end-ejection pressure/end-systolic volume (EEP/ESV) relation, giving evidence of a true positive inotropic effect. In the remaining patients, improvement in cardiac pump function was observed together with a shift of the EEP/ESV relation along the line of iso-inotropism and appeared to be the result of the vasodilatory effect of the drug alone. Data from nine patients were available for comparison with dobutamine which induced a shift upward and to the left of the EEP/ESV relation in seven patients. At the therapeutic doses chosen, the difference between the inotropic effects of the two drugs was not significant (P = 0.07). Of the three patients available for comparison who did not manifest inotropic response with enoximone, two were also dobutamine 'non-responders': they differed from the 'responder' patients in two respects: they had undergone surgery for correction of valvular disease and had significantly higher pulmonary artery pressures. The haemodynamic measurements confirmed the vasodilatory properties of enoximone; in particular, the fall in ventricular filling pressures was much greater with enoximone than with dobutamine.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Volume↗
PubMed1989

Detection of restenosis after coronary angioplasty for single-vessel disease: how reliable are exercise electrocardiography and scintigraphy in asymptomatic patients?

The diagnostic value of exercise electrocardiography and thallium myocardial scintigraphy for the detection of restenosis was assessed in 111 patients undergoing control angiography 6 months after successful coronary angioplasty. All patients were free of symptoms at the time of the study. A diameter reduction of 70% or more at the site of angioplasty was considered restenosis. The sensitivity of exercise electrocardiography is low (64%). Exercise ECG and scintigraphy are highly specific (respectively 90% and 93%). The predictive value of a positive ECG or thallium scintigraphy is poor (respectively 53% and 63%). The value of a negative scintigraphic result is slightly better than the predictive value of a negative ECG (98% vs 95%; NS). A negative exercise scintigraphy almost excludes severe restenosis. These non-invasive tests seem suitable for the detection of asymptomatic restenosis.

Angioplasty, Balloon, Coronary↗
PubMed1985

Alternative diagnostic strategies for coronary artery disease in women: demonstration of the usefulness and efficiency of probability analysis.

Alternative strategies using conditional probability analysis for the diagnosis of coronary artery disease (CAD) were examined in 93 infarct-free women presenting with chest pain. Another group of 42 consecutive female patients was prospectively analyzed. For this latter group, the physician had access to the pretest and posttest probability of CAD before coronary angiography. These 135 women all underwent stress electrocardiographic, thallium scintigraphic, and coronary angiographic examination. The pretest and posttest probabilities of coronary disease were derived from a computerized Bayesian algorithm. Probability estimates were calculated by the four following hypothetical strategies: SO, in which history, including risk factors, was considered; S1, in which history and stress electrocardiographic results were considered; S2, in which history and stress electrocardiographic and stress thallium scintigraphic results were considered; and S3, in which history and stress electrocardiographic results were used, but in which stress scintigraphic results were considered only if the poststress probability of CAD was between 10% and 90%, i.e., if a sufficient level of diagnostic certainty could not be obtained with the electrocardiographic results alone. The strategies were compared with respect to accuracy with the coronary angiogram as the standard. For both groups of women, S2 and S3 were found to be the most accurate in predicting the presence or absence of coronary disease (p less than .05). However, it was found with use of S3 that more than one-third of the thallium scintigrams could have been avoided without loss of accuracy. It was also found that diagnostic catheterization performed to exclude CAD as a diagnosis could have been avoided in half of the patients without loss of accuracy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

Validation of radionuclide cardiac output measurements during exercise.

A nongeometric radionuclide technique with correction for attenuation was used for the determination of cardiac output and stroke volume during exercise in nine normal subjects and in ten hypertensive patients. Simultaneous reference stroke volume (range 48-159 ml) and cardiac output (range 3.6-23.8 l/min) measurements were obtained by the Fick method. Data were collected at rest and during 60 degrees upright exercise, at two or three levels of increasing severity. Three statistical measurements were used for the comparison of both methods: correlation, precision, and accuracy. Radionuclide and Fick cardiac output measurements (n = 67, rest and exercise data) correlated well (r = 0.90). For stroke volume, the correlation was less (r = 0.64); however, the precision or random variability of both methods was similar for stroke volume (radionuclide: 8 ml or 9%; Fick: 16 ml or 16%). The accuracy or systematic error was defined as the mean difference between radionuclide and Fick measurements. The radionuclide method underestimated the Fick measurements. The systematic error was 18 +/- 18 ml for stroke volume and 2.4 +/- 2.4 l/m for cardiac output. A similar comparison of both methods was made on the absolute changes of stroke volume (r = 0.61; range -19 + 70 ml) and cardiac output (r = 0.82; range +1.6 + 16.4 l/m) between rest and exercise. The precision of the two methods was similar; the systematic error was 1.9 +/- 2.2 l/m for cardiac output and 6 +/- 17 ml for stroke volume. Thus, in these two groups of patients, although radionuclide and Fick cardiac output measurements at rest and during exercise correlated well, the radionuclide values were systematically and significantly lower.

Adult↗
PubMedDate not supplied

Proximal femur density in type 1 and 2 diabetic patients.

This study reports on the proximal femur mineral content in 36 Type 1 and 60 Type 2 diabetic patients. Bone mass measurements were performed in the neck, Ward's triangle and in the trochanteric area of the femur, using dual-photon absorptiometry with 153Gd. Bone mineral density (BMD) was significantly decreased in Type 1 diabetic men and women as well in Type 2 men, when compared with a non diabetic matched population. In Type 1 men, neck and Ward's triangle densities were reduced from 0.94 +/- 0.05 to 0.86 +/- 0.11 (p = 0.007) and from 0.87 +/- 0.10 to 0.74 +/- 0.14 g.cm-2 (p = 0.011), respectively. In Type 1 women, BMD was reduced from 0.97 +/- 0.10 to 0.90 +/- 0.10 g.cm-2 (p = 0.023) in the femoral neck. In Type 2 men, BMD in Ward's triangle was also significantly lower than in controls: 0.69 +/- 0.14 vs 0.76 +/- 0.19 g.cm-2, respectively (p = 0.001). In contrast, no bone loss was observed in a group of Type 2 overweight diabetic women. No statistical correlation was observed between bone loss and age, duration of diabetes, body mass index, C-peptide levels, daily insulin doses, HbA1 and the presence of diabetic complications. In conclusion, long-standing Type 1 diabetic men and women and Type 2 diabetic men have a decrease in the proximal femur bone mass. Type 2 diabetic women appear to be protected from diabetic osteopenia.

Adult↗