Biomedical subjects

Viviane de Maertelaer

Publications and source records attributed to Viviane de Maertelaer.

8 recordsLinked to original sources

PubMed2006

Pulmonary emphysema: objective quantification at multi-detector row CT--comparison with macroscopic and microscopic morphometry.

PURPOSE: To prospectively compare pulmonary function tests and helical computed tomographic (CT) indexes for quantifying pulmonary emphysema with macroscopic and microscopic morphometry. MATERIALS AND METHODS: The investigation was approved by the local ethics committee, and written informed consent was obtained from patients. Multi-detector row CT of the thorax was performed with simultaneous acquisition of four 1-mm sections in 80 patients (57 men, 23 women; age range, 38-79 years) referred for surgical resection of lung cancer. From the raw data, 1.25-mm-thick sections were reconstructed at 10-mm intervals. Relative areas of lung with attenuation coefficients lower than nine thresholds and eight percentiles of the distribution of attenuation coefficients were calculated. Relative areas and percentiles were compared with areas found macroscopically to have emphysema and with two microscopic indexes assessed on resected specimens. Pulmonary function tests were measured 24-48 hours before surgery. Spearman correlation coefficients were calculated between each set of CT data obtained with the nine tested thresholds and eight percentiles with macroscopic and microscopic measurements. RESULTS: For relative lung areas, the strongest correlation with macroscopy was observed with a threshold of -970 HU (r = 0.543, P < .001) and that with microscopy was observed at -960 and -970 HU, depending on the index considered (r = 0.592, P < .001 and r = -0.546, P < .001, respectively). For percentiles, 1st percentile showed the strongest correlation with both macroscopy (r = -0.463, P < .001) and microscopy (r = -0.573, P < .001; and r = 0.523, P < .001 for each microscopic measurement). Forced expiratory volume in 1 second and vital capacity ratio, diffusing capacity of lung for carbon monoxide, and each of the three CT indexes were complementary to predict microscopic indexes. CONCLUSION: Relative lung areas with attenuation coefficients lower than -960 or -970 HU and 1st percentile are valid indexes to quantify pulmonary emphysema on multi-detector row CT scans.

Adult↗

PubMed2005

Dentocraniofacial morphology of 21 patients with unilateral cleft lip and palate: a cephalometric study.

OBJECTIVE: To assess the skeletal and dental craniofacial proportions of unilateral cleft lip and palate patients who were operated upon using the Malek technique, and compare them with a normal group to highlight the effect of surgical correction on craniofacial development during growth. DESIGN: Retrospective. METHODS: The cleft palate was closed using the Malek technique in a single operation at 3 months for 11 patients (complete closure of lip and palate) and in a two-stage operation for 10 patients (soft palate at 3 months, lip and hard palate at 6 months). Comparisons were made with a normal control group. Angular and linear measurements of anterior and posterior dimensions of the upper and lower compartments of the face were measured in the 7th and 12th years. RESULTS AND CONCLUSION: No significant differences were observed between the two groups of palate technique repair, although significant differences were observed between craniofacial dimensions of normal versus cleft lip and palate patients. At a skeletal level, the maxilla and mandible were retrusive relative to the cranial base in the cleft lip and palate group. In fact, there was a backward rotation of the palatal plane with repercussions on the maxillo-mandibular complex position. Furthermore, the maxilla was shorter than in normal patients, whereas the mandible was normally shaped. The upper incisors were retroclined and they locked the lower incisors in linguoversion. There was a posterior skeletal deficit of the respiratory compartment, compensated by more marked posterior maxillary alveolar growth. Facial growth in cleft lip and palate patients followed the same pattern, but was delayed compared with normal patients.

Age Factors↗

PubMed2004

Acute appendicitis: comparison of low-dose and standard-dose unenhanced multi-detector row CT.

PURPOSE: To prospectively compare low- and standard-dose unenhanced multi-detector row computed tomography (CT) in patients suspected of having acute appendicitis. MATERIALS AND METHODS: Ninety-five consecutive patients underwent two unenhanced multi-detector row CT examinations with 4 x 2.5-mm collimation, 120 kVp, and 30 and 100 effective mAs. Two radiologists independently read the images obtained at each dose during two sessions. Readers recorded visualization of the appendix and presence of gas in its lumen, appendicolith, periappendiceal fat stranding, cecal wall thickening, and abscess or phlegmon to measure the diameter of the appendix and to propose diagnosis (appendicitis or alternative). Data were compared according to dose and reader, with definite diagnosis established on basis of surgical findings (n = 37) or clinical follow-up. chi(2) tests and logistic regression were used. Measurement agreements were assessed with Cohen kappa statistics. RESULTS: Twenty-nine patients had a definite diagnosis of appendicitis. No difference was observed between the frequency of visualization of the appendix (P =.874) neither in its mean diameter (P =.101-.696, according to readers and sessions) nor in the readers' overall diagnosis (P =.788) at each dose. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of each sign were not different between doses. Fat stranding, appendicolith, and diameter were the most predictive signs, regardless of dose, yielding approximately 90% of correct diagnoses. The ability to propose a correct alternative diagnosis was not influenced by the dose. CONCLUSION: Low-dose unenhanced multi-detector row CT has similar diagnostic performance as standard-dose unenhanced multi-detector row CT for the diagnosis of acute appendicitis.

Acute Disease↗

PubMed2004

Prediction of severity of symptoms in iatrogenic ovarian hyperstimulation syndrome by follicle-stimulating hormone receptor Ser680Asn polymorphism.

The ovarian hyperstimulation syndrome (OHSS) is a potentially life-threatening complication of ovarian stimulation treatments for in vitro fertilization (i.v.f.). Recently, three different mutations of the FSH receptor (FSHr) have been identified in patients who presented recurrent spontaneous OHSS. This prompted us to study a possible association between coding polymorphisms of the FSHr and the occurrence of iatrogenic OHSS. We sequenced the region of the FSHr gene encompassing the A307T and S680N polymorphisms of exon 10 of FSHr in 37 Caucasian females who developed OHSS after an IVF cycle in our fertility clinic, 130 Caucasian female patients who were treated by i.v.f. but never developed OHSS, and 99 Caucasian female controls. The FSHr allele frequencies in the Caucasian control population were identical to what has already been published (39% S680 61% N680). The control i.v.f. population was enriched in the S680 allele compared with the Caucasian control population (51% S680; 49% N680; P = 0.016). The OHSS population had a even higher enrichment in the S680 allele compared with the Caucasian control population (57% S680; 43% N680; P = 0.010). These results were unexpected, because the frequency of the S680 allele was previously found to be increased among poor responders to FSH stimulation. In a second phase, we studied FSHr allele frequencies according to the severity of OHSS. Interestingly, a significant enrichment in the allele N680 was observed as the severity of OHSS increased (P = 0.034). Bearing in mind the limitations of the small number of patients studied and the possibility of sampling biases, these results suggest that the genotype in position 680 of the FSHr cannot predict which patients will develop OHSS, but could be a predictor of severity of symptoms among OHSS patients.

Adult↗

PubMed2003

Aneurysmal sizing after endovascular repair in patients with abdominal aortic aneurysm: interobserver variability of various measurement protocols and its clinical relevance.

The aim of this study was to determine the variability of various measurement protocols for measurement of abdominal aortic aneurysm (AAA) and the clinical relevance of variability. Three radiologists performed computed tomographic angiography measurements of both the aorta and the largest portion of the aneurysm on selected axial slices. Then measurements of the largest portion of the aneurysm were performed on unselected axial slices, sagittal and coronal reformatted. Finally, aortic volume was calculated. Measurements and volume calculation were performed before and after endovascular repair and assessed: Part 1: interobserver variability for maximum anteroposterior (MAP) and maximum transverse (MTR) diameters on selected slices; part 2: interobserver variability for unselected slices considering MAP and MTR; part 3: interobserver variability considering maximum diameter in any direction (MAD); part 4: interobserver variability for sagittal (SAG) and coronal (COR) free curved multiplanar reformation (MPR); and part 5: volume calculations. We then determined which technique of measurement was the most clinically relevant for detecting changes in aneurysm size or aortic volume. Parts 1 and 2: interobserver variability was 4.1 mm for both MAP and MTR; part 3: interobserver variability was 7 mm for MAD; part 4: interobserver variability was 5.5 mm (COR) and 4.9 mm (SAG); part 5: interobserver variability for volume was 5.5 ml. A combination of MAP and MTR was the most useful for detecting aortic modification. Volume calculation was needed in only a few cases. We recommend avoiding MAD and MPR measurements and suggest instead measuring both maximum anteroposterior and maximum transverse diameters. If aneurysm size remains stable after endovascular repair, aneurysm volume should be measured.

Aged↗

PubMed2003

Low-dose unenhanced multidetector CT of patients with suspected renal colic.

OBJECTIVE: This study is designed to assess the intraobserver and interobserver agreements and the diagnostic performances of low-dose unenhanced multidetector CT (MDCT) in patients with suspected renal colic. SUBJECTS AND METHODS: The study included 106 patients who underwent unenhanced MDCT with 4 x 2.5 mm collimation, 120 kVp, 30 mAs, and, if necessary, additional focused acquisitions at 60 or 120 mAs on areas with an equivocal ureteral stone or with significant image noise. The effective radiation dose was computer-simulated with software based on the Monte Carlo model and International Commission on Radiological Protection recommendations. CT scans were archived and independently reviewed by three radiologists during two interpretation sessions on a workstation with three dimensions functions. Intraobserver and interobserver agreements were calculated with the kappa statistics. Accuracy for detection of ureteral stone on low-dose MDCT was calculated by comparison with combined clinical (stone passage), surgical (stone retrieval, extracorporeal shock wave lithotripsy), biologic (urinalysis, urine culture), and other imaging (excretory urography, standard-dose MDCT, follow-up sonography, and abdominal radiography) findings or by evidence for an alternative diagnosis. RESULTS: Ureteral stones were present in 38 (36%) of 106 patients. Thirty-six of 38 ureteral stones were detected by low-dose MDCT. From reviewer to reviewer, the number of true-positive, false-positive, true-negative, and false-negative findings ranged, respectively, from 34 to 36, 1 to 4, 64 to 68, and 2 to 4. The corresponding sensitivity, specificity, and accuracy ranged from 89.5% to 94.7%, from 94.1% to 100%, and from 93.4% to 98.1%, respectively. The intraobserver and interobserver agreements were excellent, with kappa values ranging from 0.87 to 0.98. In 13 patients, an alternative diagnosis explaining the patient's symptoms was proposed by all reviewers using images obtained at 30 mAs. No additional or alternative diagnosis was found at standard dose. At 30 mAs, the mean effective dose was 1.2 mSv in men and 1.9 mSv in women. Additional acquisitions at 60 mAs, all focused on the lower pelvis, were acquired in 20 patients, but the corresponding images were needed by the reviewers for only six of them. The acquisitions at 60 mAs were responsible for an additional mean effective dose of 0.5 in men and 0.8 mSv in women. CONCLUSION: Our study shows that low-dose unenhanced MDCT is appropriate for the diagnosis of ureteral stones, and that it provides excellent intraobserver and interobserver agreements and does not obscure alternative diagnoses.

Adolescent↗

PubMed2002

Peripheral blood mononuclear cell proliferation to heat shock protein-70 derived from autologous lung carcinoma.

In animals, tumor-derived heat shock proteins (HSP) induce immune-mediated protection against autologous cancer. We investigated whether HSP-70 derived from human lung carcinoma are also complexed to tumor-specific antigens. Peripheral blood mononuclear cells collected 10 days after surgery from patients with lung cancer were stimulated with HSP-70 purified from autologous and heterologous tumors. The stimulation index (SI) obtained when stimulating cells with autologous tumor-derived HSP-70 averaged 3.07 +/- 0.75 in patients with lung cancer and 1.57 +/- 0.33 in control subjects (p < 0.001 by analysis of variance). No significant stimulation was observed with HSP-70 derived either from the majority of heterologous tumors or from autologous tumor-free lung tissue. SI decreased from 3.59 +/- 0.65 to 1.65 +/- 0.38 in six patients tested again 3 months after surgery (p = 0.02 by Wilcoxon test for paired data). HSP-70 derived from lung carcinoma are shown to be associated with T cell antigens. The T cell reactivity appears transient and restricted to antigens complexed to HSP-70 derived from autologous tumors only. This suggests that the antigenicity of human lung tumors is unique, which may be crucial for the design of new vaccines.

Adenocarcinoma↗

PubMed2002

Endoscopic implantation of a biopolymer in the lower esophageal sphincter for gastroesophageal reflux: a pilot study.

BACKGROUND: GERD is the most frequent disorder of the esophagus. Endoscopic minimally invasive treatment is desirable. However, the results of injection techniques have been disappointing. METHODS: A pilot study was conducted in patients with GERD, who required continuous therapy with a proton pump inhibitor, in which ethylene-vinyl-alcohol was injected into the muscle of the gastric cardia. Primary endpoints were the safety of the procedure, the effect on lower esophageal sphincter pressure and the stability of the injected material. A secondary endpoint was the effect on heartburn score after discontinuation of treatment with a proton pump inhibitor. RESULTS: Ethylene-vinyl-alcohol injection into the cardia resulted in circular diffusion of the product in 10 of 15 cases, suggesting that implantation into the muscle is feasible. Lower esophageal sphincter pressure was increased in 13 of 15 cases at 1 month and was sustained at a median follow-up of 6 months (range 4-12 months). Mean plus minus SEM of lower esophageal sphincter pressures (15 patients) were 12.2 plus minus 0.9, 18.7 plus minus 1.5 (p = 0.001 at baseline), and 16.7 plus minus 1.3 mm Hg (p = 0.038 from baseline) at, respectively, baseline, 1 month follow-up, and final follow-up. There was also a sustained reduction in heartburn score (off proton pump inhibitor) (3.40 plus minus 0.13 vs. 1.53 plus minus 0.24 and 1.87 plus minus 0.26 at baseline vs. 1 month and final follow-up, respectively; p < 0.01). Nine of the 15 patients had more than 50% of the injected material in place at second follow-up (at 6 months for 8 patients; at 12 months for 1 patient). In only 2 patients was there loss of more than 75% of injected ethylene-vinyl-alcohol. Persistence of greater than 50% of the material was associated with achievement of a circular injection. Only 4 patients had to resume therapy with a proton pump inhibitor. Mild retrosternal discomfort was observed in 8 patients; this disappeared in all cases after a maximum of 3 days. CONCLUSIONS: Ethylene-vinyl-alcohol implantation in the muscle of the cardia is feasible and safe. It leads to a sustained increase in resting lower esophageal sphincter pressure. This is associated with a sustained improvement in heartburn score for patients who previously required continuous therapy with a proton pump inhibitor.

Absorbable Implants↗