113 results on '"Filip Claus"'
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2. Less Common Causes of Acute Abdomen
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Lieven Van Hoe, Filip Claus, and Piet Vanhoenacker
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Medical physics. Medical radiology. Nuclear medicine ,R895-920 - Abstract
In this presentation, less common causes of acute abdomen are reviewed. Emphasis is on three topics. First, the anatomy of the superior mesenteric vein and mesentery is reviewed, together with the anatomical basis and clinical/radiological presentation of midgut volvulus. Emphasis is on diagnostic clues (whirl sign, abnormal position of cecum, small bowel, and third part of duodenum) and pitfalls (positional variation of small bowel loops with pseudo-twisting of mesenteric vessels). Second, atypical presentations of acute appendicitis and appendagitis, as well as their mimics, are discussed. Finally, an overview is given of uncommon but important causes of free intraperitoneal fluid in patients with acute abdominal pain.
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- 2016
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3. Acute Abdominal Pathology in Pregnant Women
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Filip Claus
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Medical physics. Medical radiology. Nuclear medicine ,R895-920 - Published
- 2016
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4. A case report: septic shock due to (tropical) pyomyositis and multiple metastatic embolisms caused by Panton Valentine Leukocidin-positive methicillin-sensitive staphylococcus aureus in a 12-year-old boy
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Kristien Van Vaerenbergh, Valérie Vanbiervliet, Ignace Demeyer, and Filip Claus
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Adult ,Male ,Methicillin-Resistant Staphylococcus aureus ,Pediatrics ,medicine.medical_specialty ,Staphylococcus aureus ,Pyomyositis ,Adolescent ,Embolism ,medicine.disease_cause ,03 medical and health sciences ,Methicillin ,Young Adult ,0302 clinical medicine ,Leukocidins ,Medicine ,Humans ,Medical history ,030212 general & internal medicine ,Child ,business.industry ,Septic shock ,Osteomyelitis ,General Medicine ,Emergency department ,Staphylococcal Infections ,bacterial infections and mycoses ,medicine.disease ,Shock, Septic ,Blunt trauma ,030220 oncology & carcinogenesis ,Panton–Valentine leukocidin ,business - Abstract
Case Report: A 12-year-old boy, of Congolese roots and without medical history, first presented to our Emergency Department 3 days after blunt trauma of the left ankle. The boy represented on two more occasions in the next 3 days due to ongoing pain. On the last occasion he presented with severe hypoglycaemia. He was diagnosed with severe septic shock, secondary to subperiosteal abscess formation / osteomyelitis of the ankle. The patient was transferred to the paediatric intensive care unit where appropriate medical care was provided, including broad-spectrum antibiotic therapy, high dose vasopressor / inotropic support, surgical debridement of abscesses and below-knee amputation.Panton Valentine Leukocidin Toxin and Pyomyositis Tropicalis: The causative organism was a methicillin-susceptible S. aureus, which upon further identification was a carrier of the PVL (Panton Valentine leukocidin) toxin. This pathogen is responsible for severe musculoskeletal infections. In children these infections are often associated with more severe clinical course requiring a higher need for surgical intervention and longer hospital stay.Tropical pyomyositis is a disease caused by Staphylococcus aureus, often seen in tropical countries, and classically presented with muscle abscesses. Young males between the ages of 10-40 years old are the most susceptible, and often present with a history of blunt trauma. Treatment generally requires a combination of an anti-staphylococcal agent, and an anti-toxic agent blocking bacterial protein-synthesis of PVL. Source control by surgical debridement also plays a major role in the treatment of PVL-infection. Despite agressive treatment, mortality still varies from 0.5% to 2%.
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- 2021
5. MP24-10 THE ROLE OF MPMRI IN STRATIFYING PATIENTS WITH INCREASED RISK OF PROSTATE CANCER
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Wouter Everarts, Raymond Oyen, Maarten Albersen, Filip Claus, Lisa Moris, Liesbeth Dewever, Lauwers Nathalie, Cindy Mai, Vanhoutte Els, Steven Joniau, and Uros Milenkovic
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Oncology ,medicine.medical_specialty ,Prostate cancer ,Increased risk ,business.industry ,Urology ,Internal medicine ,medicine ,medicine.disease ,business ,Multiparametric Magnetic Resonance Imaging - Abstract
INTRODUCTION AND OBJECTIVES:Current evidence strongly supports the use of multiparametric magnetic resonance imaging (mpMRI) pre-biopsy in men with a suspicion of prostate cancer (PCa) based on ele...
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- 2019
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6. Congenital cytomegalovirus infection: contribution and best timing of prenatal MR imaging
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Roland Devlieger, T. Cos, Walter Foulon, Elise Van der Valk, Jacques Jani, Raymond Oyen, Mieke Cannie, Veerle Cossey, Ina Foulon, Filip Claus, Astrid Leus, Anja Bernaert, Luc De Catte, Mina Leyder, Supporting clinical sciences, Medical Imaging and Physical Sciences, Gyneacology-Urology, Surgical clinical sciences, Vriendenkring VUB, Mother and Child, Medical Imaging, and Microbiology and Infection Control
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Male ,Fetal MRI ,medicine.medical_specialty ,Congenital CMV ,Hearing Loss, Sensorineural ,Cytomegalovirus ,Gestational Age ,Prenatal diagnosis ,Ultrasonography, Prenatal ,Polar temporal lesions ,sensorineural hearing loss ,03 medical and health sciences ,0302 clinical medicine ,Predictive Value of Tests ,Pregnancy ,Prenatal Diagnosis ,otorhinolaryngologic diseases ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,030212 general & internal medicine ,Neuroradiology ,Medicine(all) ,030219 obstetrics & reproductive medicine ,medicine.diagnostic_test ,Receiver operating characteristic ,business.industry ,Infant, Newborn ,Brain ,Infant ,Gestational age ,Magnetic resonance imaging ,General Medicine ,Prognosis ,medicine.disease ,Magnetic Resonance Imaging ,Hyperintensity ,Fetal Diseases ,Fetal infection ,Predictive value of tests ,Cytomegalovirus Infections ,Feasibility Studies ,Female ,Sensorineural hearing loss ,Radiology ,business ,Follow-Up Studies - Abstract
OBJECTIVE: To predict sensorineural hearing loss (SNHL) and neurological impairment in congenital cytomegalovirus (cCMV) infection using MR imaging and define the best timing in pregnancy for prenatal assessment. METHODS: In 121 patients with confirmed cCMV infection, brain features at MR imaging were respectively graded from 1 to 5: normal; isolated frontal/parieto-occipital hyperintensity; temporal periventricular hyperintensity; temporal/occipital cysts and/or intraventricular septa; migration disorders. Grading was correlated with postnatal SNHL and neurological impairment using regression analysis. In 51 fetuses with MR examinations at 26.9 and 33.0 weeks, the predictive value of SNHL and neurological impairment was compared using ROC curves. RESULTS: Postnatal follow-up showed SNHL in 18 infants and neurological impairment in 10. MR grading was predictive of SNHL and of neurological impairment (P
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- 2016
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7. In vivo evidence by magnetic resonance volumetry of a gestational age dependent response to tracheal occlusion for congenital diaphragmatic hernia
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Olga Gómez, Katika Nawapun, Daysi Diaz-Cobos, Filip Claus, Julio Jimenez, Michael Aertsen, Eduard Gratacós, Jan Deprest, and Mary Patrice Eastwood
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Fetus ,medicine.diagnostic_test ,business.industry ,Obstetrics and Gynecology ,Diaphragmatic breathing ,Gestational age ,Congenital diaphragmatic hernia ,Magnetic resonance imaging ,Balloon ,medicine.disease ,In utero ,Anesthesia ,Occlusion ,Medicine ,business ,Nuclear medicine ,Genetics (clinical) - Abstract
Objective We aimed to assess in vivo changes in lung and liver volumes in fetuses with isolated congenital diaphragmatic hernia, either expectantly managed or treated in utero. Method This is a secondary analysis of prospectively collected data at two fetal therapy centers. We used archived magnetic resonance images of fetuses taken ≥7 days apart, creating paired observations in 20 expectantly managed cases, 41 with a second magnetic resonance prior to balloon reversal and 64 after balloon removal. We measured observed to expected total fetal lung volume (O/E TFLV) and liver-to-thoracic volume ratio. We calculated changes in volume as compared with the initial measurement and its rate as a function of gestational age (GA) at occlusion. Results The liver-to-thoracic volume ratio did not change in either group. In expectantly managed fetuses, O/E TFLV did not increase with gestation. In fetuses undergoing tracheal occlusion, the measured increase in volume was 2.6 times larger with balloon in place as compared with that after its removal. GA at tracheal occlusion was an independent predictor of the O/E TFLV. The net rate seems to initially increase and plateau at a maximum of 1.5% per week by 35 to 45 days after occlusion. Conclusions Tracheal occlusion induces a net increase in volume, its magnitude essentially dependent on the GA at occlusion.
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- 2015
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8. High-Resolution 1H NMR Spectroscopy Discriminates Amniotic Fluid of Fetuses with Congenital Diaphragmatic Hernia from Healthy Controls
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Sabine Van Huffel, Jan Deprest, Uwe Himmelreich, Inga Sandaite, Filip Claus, Anca R Croitor-Sava, Veronika Beck, and Tom Dresselaers
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Male ,medicine.medical_specialty ,Magnetic Resonance Spectroscopy ,Amniotic fluid ,Gestational Age ,Prenatal diagnosis ,Creatine ,Biochemistry ,Gastroenterology ,chemistry.chemical_compound ,Fetus ,Prenatal Diagnosis ,Internal medicine ,medicine ,Humans ,Lung ,Principal Component Analysis ,Creatinine ,business.industry ,Congenital diaphragmatic hernia ,Gestational age ,General Chemistry ,Anatomy ,Amniotic Fluid ,medicine.disease ,3. Good health ,medicine.anatomical_structure ,chemistry ,Case-Control Studies ,Metabolome ,Female ,Hernias, Diaphragmatic, Congenital ,business - Abstract
Lung hypoplasia in congenital diaphragmatic hernia (CDH) is a life-threatening birth defect. Severe cases can be offered tracheal occlusion to boost prenatal lung development, although defining those to benefit remains challenging. Metabonomics of (1)H NMR spectra collected from amniotic fluid (AF) can identify general changes in diseased versus healthy fetuses. AF embodies lung secretions and hence might contain pulmonary next to general markers of disease in CDH fetuses. AF from 81 healthy and 22 CDH fetuses was collected. NMR spectroscopy was performed at 400 MHz to compare AF from fetuses with CDH against controls. Several advanced feature extraction methods based on statistical tests that explore spectral variability, similarity, and dissimilarity were applied and compared. This resulted in the identification of 30 spectral regions, which accounted for 80% variability between CDH and controls. Combination with automated classification discriminates AF from CDH versus healthy fetuses with up to 92% accuracy. Within the identified spectral regions, isoleucine, leucine, valine, pyruvate, GABA, glutamate, glutamine, citrate, creatine, creatinine, taurine, and glucose were the most concentrated metabolites. As the metabolite pattern of AF changes with fetal development, we have excluded metabolites with a high age-related variability and repeated the analysis with 12 spectral regions, which has resulted in similar classification accuracy. From this analysis, it was possible to distinguish between AF from CDH fetuses versus healthy controls independent of gestational age.
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- 2015
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9. Correlation of observed-to-expected total fetal lung volume with intrathoracic organ herniation on magnetic resonance imaging in fetuses with isolated left-sided congenital diaphragmatic hernia
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Jan Deprest, Filip Claus, Jute Richter, Maissa Rayyan, Inga Sandaite, Philip DeKoninck, Katika Nawapun, and Mary Patrice Eastwood
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Thorax ,Fetus ,medicine.medical_specialty ,Radiological and Ultrasound Technology ,medicine.diagnostic_test ,business.industry ,Stomach ,Obstetrics and Gynecology ,Gestational age ,Congenital diaphragmatic hernia ,Magnetic resonance imaging ,General Medicine ,medicine.disease ,Pulmonary hypoplasia ,medicine.anatomical_structure ,Reproductive Medicine ,medicine ,Radiology, Nuclear Medicine and imaging ,Lung volumes ,Radiology ,business - Abstract
Objectives To assess using fetal magnetic resonance imaging (MRI) the relationship between the position of the stomach as well as the volume of herniation of organs into the thorax, and the observed-to-expected total fetal lung volume (o/e-TFLV), as a measure of pulmonary hypoplasia, in fetuses with isolated left-sided congenital diaphragmatic hernia (LCDH). Methods This was a single-center retrospective study using archived MR images from fetuses > 20 weeks' gestation evaluated for isolated LCDH over an 11-year period between July 2002 and September 2013. We retrieved data on the gestational age at MRI, o/e-TFLV and liver position. Images were also reviewed by a single operator to determine retrospectively the position of the stomach as well as the proportion of the total thorax volume occupied by the herniated fetal liver, stomach and other viscera. Following confirmation of reproducibility, we assessed the correlation of intrathoracic organ volumes and stomach position with o/e-TFLV. Results The study included 205 fetuses which underwent a total of 259 MR examinations. The reproducibility of organ volume measurements was excellent (intraclass correlation coefficient range, 0.928–0.997). The average time spent to obtain intrathoracic organ volumes ranged from 2.28 to 5.13 min. Of all herniated organ-to-thoracic volume ratios, the liver-to-thoracic volume ratio had the strongest correlation with o/e-TFLV (ρ = −0.429, P
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- 2015
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10. Comparison of matching by body volume or gestational age for calculation of observed to expected total lung volume in fetuses with isolated congenital diaphragmatic hernia
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Katika Nawapun, Filip Claus, Inga Sandaite, L. De Catte, Jute Richter, Philip DeKoninck, and Jan Deprest
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Intraclass correlation ,Gestational Age ,Body volume ,Pregnancy ,Prenatal Diagnosis ,Body Size ,Humans ,Medicine ,Radiology, Nuclear Medicine and imaging ,Lung volumes ,Small lungs ,Lung ,Retrospective Studies ,Observer Variation ,Fetus ,Radiological and Ultrasound Technology ,medicine.diagnostic_test ,business.industry ,Reproducibility of Results ,Obstetrics and Gynecology ,Congenital diaphragmatic hernia ,Gestational age ,Magnetic resonance imaging ,General Medicine ,Anatomy ,medicine.disease ,Magnetic Resonance Imaging ,Cross-Sectional Studies ,Reproductive Medicine ,Female ,Hernias, Diaphragmatic, Congenital ,Lung Volume Measurements ,business ,Nuclear medicine - Abstract
To determine the bias induced by matching fetuses according to gestational age (GA) or fetal body volume (FBV) when calculating the observed to expected total fetal lung volume (o/e TFLV) in cases of isolated congenital diaphragmatic hernia (CDH).This was a single-center, retrospective study on archived magnetic resonance (MR) images of fetuses with isolated CDH over a 10-year period. We retrieved the TFLV, GA and o/e TFLVGA , and delineated FBV to obtain TFLVFBV in each case. We evaluated the relationship between o/e TFLVFBV and o/e TFLVGA by Bland-Altman analysis. All outliers were manually identified, and their specific clinical features were retrieved.Records of a total of 377 MR examinations of 225 fetuses were identified and included in the analysis. The mean ( ± SD) time spent on FBV measurement was 16.12 ± 4.95 min. On reproducibility analysis of FBV measurement (n = 10), the intraobserver intraclass correlation coefficient (ICC) was 0.998 and the interobserver ICC was 0.999. FBV was highly correlated with GA (R(2) = 0.899; P 0.0001). There was good agreement between o/e TFLVGA and o/e TFLVFBV , with a mean difference of -1.10% and 95% limits of agreement of -8.58 to 6.39. There were no outliers in fetuses that had an o/e TFLV 25%. Discrepancies induced by different methods were more likely in women with a body mass index ≥ 25 kg/m(2) (+16.5%), fetuses with an estimated fetal weight (EFW) ≤ 10(th) centile (+21.3%) or an EFW 90(th) centile (+14.7%).Discrepancies in matching by FBV and GA when calculating o/e TFLV are more likely in fetuses with an abnormal EFW or in fetuses carried by overweight women. The clinical relevance of using FBV rather than GA for calculation of the o/e TFLV might be limited, as there was no discrepancy between the two methods in fetuses with small lungs ( 25%), which is the group of most interest for lung volume assessment.
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- 2014
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11. Incidence of bowel wall oedema on computed tomography exams and association with diarrhoea in renal cell carcinoma patients treated with sunitinib
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Pascal Wolter, Frederik De Keyzer, Herlinde Dumez, Benoit Beuselinck, Filip Claus, Liesbeth Cornelissen, Evelyne Lerut, and Hendrik Van Poppel
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Adult ,Diarrhea ,Male ,medicine.medical_specialty ,Indoles ,Antineoplastic Agents ,urologic and male genital diseases ,Belgium ,Renal cell carcinoma ,Multidetector Computed Tomography ,Sunitinib ,medicine ,Carcinoma ,Edema ,Humans ,Pyrroles ,Radiology, Nuclear Medicine and imaging ,Adverse effect ,Carcinoma, Renal Cell ,Aged ,Retrospective Studies ,Aged, 80 and over ,medicine.diagnostic_test ,business.industry ,Incidence ,Incidence (epidemiology) ,digestive, oral, and skin physiology ,Retrospective cohort study ,Interventional radiology ,General Medicine ,Middle Aged ,medicine.disease ,Kidney Neoplasms ,female genital diseases and pregnancy complications ,Intestines ,Female ,Radiology ,medicine.symptom ,business ,Follow-Up Studies ,medicine.drug - Abstract
The purpose of this study was to retrospectively assess the incidence of bowel wall oedema on computed tomography (CT) in patients with renal cell carcinoma (RCC) treated with sunitinib, and to investigate its association with diarrhoea. We conducted a retrospective analysis of all RCC patients treated with sunitinib at our hospital between December 2005 and December 2011. The presence or absence of bowel wall oedema on these CT examinations was scored. The presence of diarrhoea preceding, during, or after sunitinib treatment was identified from the patient files and retrospectively graded. For 54 of 87 patients, bowel wall oedema was present on at least one CT examination. Of these 54 patients, the right-sided colonic segment was affected in 87 %. Diarrhoea was the most common reported adverse event during treatment, with 58 patients (67 %) having grade 1/2 diarrhoea and 9 patients (10 %) having grade 3. There was a statistically significant correlation between the incidence of CT-scored bowel oedema and diarrhoea during sunitinib treatment (P = 0.004). This study shows a very high incidence of bowel wall oedema and a strong correlation between the incidence of bowel wall oedema and diarrhoea in patients treated with sunitinib. • Sunitinib is routinely used in patients with advanced renal cell carcinoma. • Diarrhoea is the most common reported adverse event during sunitinib treatment. • Incidence of bowel oedema and diarrhoea during sunitinib treatment is correlated. • Radiologists should avoid misinterpretation of bowel oedema as infectious colitis.
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- 2014
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12. Mesh contraction: in vivo documentation of changes in apparent surface area utilizing meshes visible on magnetic resonance imaging in the rabbit abdominal wall model
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Masayuki Endo, Andrew Feola, Jan Deprest, Jarek Vlacil, Filip Claus, Alexander Engels, S Manodoro, and Nikhil Sindhwani
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Urology ,Polypropylenes ,Abdominal wall ,Perimeter ,In vivo ,Materials Testing ,Animals ,Medicine ,Marlex ,Sutures ,medicine.diagnostic_test ,business.industry ,Abdominal Wall ,Biomechanics ,Obstetrics and Gynecology ,Magnetic resonance imaging ,Anatomy ,Surgical Mesh ,Magnetic Resonance Imaging ,medicine.anatomical_structure ,Surgical mesh ,Abdomen ,Equipment Failure ,Female ,Polyvinyls ,Rabbits ,business ,Biomedical engineering - Abstract
Our aim was to analyze the apparent contraction of meshes in vivo after abdominal wall reconstruction and evaluate histological and biomechanical properties after explantation.Nine New Zealand female rabbits underwent repair of two full-thickness 25 × 30-mm midline defects in the upper and lower parts of the abdomen. These were primarily overlaid by 35 × 40-mm implants of a polyvinylidene fluoride (PVDF) DynaMesh (n = 6) or polypropylene meshes Ultrapro (n = 6) and Marlex (n = 6). Edges of the meshes were secured with iron(II,III) oxide (Fe(3)O(4))-loaded PVDF sutures. Magnetic resonance images (MRIs) were taken at days 2, 30 and 90 after implantation. The perimeter of the mesh was traced using a 3D spline curve. The apparent surface area or the area within the PVDF sutures was compared with the initial size using the one-sample t test. A two-way repeat analysis of variance (ANOVA) was used to compare the apparent surface area over time and between groups.PVDF meshes and sutures with Fe(3)O(4) could be well visualized on MRI. DynaMesh and Marlex each had a 17 % decrease in apparent surface area by day 2 (p 0.001 and p = 0.001), respectively, which persisted after day 90. Whereas there was a decrease in apparent surface area in Ultrapro, it did not reach significance until day 90 (p = 0.01). Overall, the apparent surface area decreased 21 % in all meshes by day 90. No differences in histological or biomechanical properties were observed at day 90.There was a reduction in the apparent surface area between implantation and day 2, indicating that most mesh deformation occurs prior to tissue in-growth.
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- 2014
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13. A pictorial essay on fetal rabbit anatomy using micro-ultrasound and magnetic resonance imaging
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Masayuki Endo, Jaan Toelen, Luc De Catte, Jan Deprest, Jute Richter, Ben Van Calster, Inga Sandaite, Filip Claus, Uwe Himmelreich, and Philip DeKoninck
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Fetus ,Pregnancy ,medicine.diagnostic_test ,business.industry ,Obstetrics and Gynecology ,Gestational age ,Magnetic resonance imaging ,Umbilical artery ,Anatomy ,medicine.disease ,Umbilical vein ,medicine.artery ,medicine ,Gestation ,business ,Genetics (clinical) ,Ductus venosus - Abstract
Introduction With this pictorial essay, we aimed to provide gestational age specific reference ranges of relevant fetal structures using micro-ultrasound, as well as its correlation with postmortem MRI and whole body sections. Material and Methods Time-mated pregnant rabbits (n = 24) were assessed once at various gestational ages in the second half of pregnancy (15, 17, 21 to 23, 25 to 28, and 30 to 31 days; term = 31 days). We obtained biometric data, together with Doppler flow patterns in the ductus venosus, umbilical artery and umbilical vein. After euthanasia, micro-ultrasound images were compared with images obtained by 9.4 Tesla MRI and whole body paraffin sections at 15, 23, 26, and 28 days. Results We constructed biometric normative curves, which showed a significant correlation with gestational age. The pulsatility index (PI) in the umbilical artery decreased with gestation (PI = 5.746–0.2969(GA) + 0.004931(GA)2; R2 = 0.30), whereas pulsatility index for veins (PIV) in the ductus venosus remained constant (median PIV = 0.82 (0.60–1.12)). In this report, we provide an anatomical atlas of fetal thoracic development using both micro-ultrasound and MRI. Conclusion We describe anatomical fetal leporine development as can be visualized by micro-ultrasound and MR imaging. The reported reference ranges may be useful for researchers using the fetal rabbit model. © 2013 John Wiley & Sons, Ltd.
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- 2013
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14. Calculation of membrane tension in selected sections of the pelvic floor
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Edoardo Mazza, Yves Ozog, Kim Haest, Filip Claus, Jan Deprest, and Dirk De Ridder
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Adult ,Urology ,Abdominal cavity ,Ellipse ,Models, Biological ,Pelvic Organ Prolapse ,Pressure ,Humans ,Medicine ,Pelvis ,Aged ,Ultrasonography ,Aged, 80 and over ,Mucous Membrane ,Pelvic floor ,medicine.diagnostic_test ,business.industry ,Ultrasound ,Obstetrics and Gynecology ,Magnetic resonance imaging ,Pelvic Floor ,Anatomy ,Middle Aged ,Pelvic cavity ,Circumference ,Magnetic Resonance Imaging ,medicine.anatomical_structure ,Case-Control Studies ,Female ,Stress, Mechanical ,business - Abstract
A mathematical model to estimate membrane tensions (Mt) at the urogenital hiatus and midpelvis in patients with and without prolapse is proposed. For that purpose the complex structures of the pelvic floor were simplified and, based on assumptions concerning geometry and loading conditions, Laplace's law was used to calculate Mt. The pelvic cavity is represented by an ellipsoid in which the midpelvic and hiatal sections are described by an ellipse. The downwards forces within the pelvis (F(in)) are in equilibrium with the support forces within its walls (F(w)). F(in) is the abdominal pressure (PABD) multiplied by the area A of the ellipse. The force inside the tissues (F(w)) is distributed along the circumference of the ellipse C. The Mt can be approximated as Mt = (PABD.A)/C (N/m). Mt-α accounts for the angle α which describes tissue orientation with respect to the anatomical section and is calculated as Mt-α = Mt/sin(α).We conducted a retrospective study on archived magnetic resonance imaging scans (n = 20) and ultrasound images in patients with (n = 50) or without prolapse (n = 50) and measured actual geometrical variables. PABD was measured in patients with and without prolapse (n = 20).Mt at the urogenital hiatus at rest is 0.35 N/cm. They significantly increase with the Valsalva manoeuvre, by a factor of 2.3 (without prolapse) to 3.6 (with prolapse).Calculated Mt are much lower than what is reported for the abdominal cavity. Prolapse patients have significantly larger Mt, which during the Valsalva manoeuvre increase more than in healthy subjects.
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- 2013
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15. A morphometric study of the human fetal heart on post-mortem 3-tesla magnetic resonance imaging
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Filip Claus, Luc De Catte, Jan Deprest, Philippe Moerman, Marc Gewillig, Luigi Fedele, and Inga Sandaite
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3 Tesla Magnetic Resonance Imaging ,medicine.medical_specialty ,Fetus ,Aorta ,business.industry ,Obstetrics and Gynecology ,Gestational age ,medicine.anatomical_structure ,medicine.artery ,Internal medicine ,Cardiac chamber ,Ductus arteriosus ,Pulmonary artery ,cardiovascular system ,Cardiology ,Medicine ,Gestation ,business ,Genetics (clinical) - Abstract
Objective To report on the feasibility of assessing cardiac structures on post-mortem 3-tesla MRI (pmMRI) and to provide morphometric data in fetuses without cardiac abnormalities. Methods Retrospective single center study on 3T pmMRI of 39 consecutive fetuses without cardiac abnormalities (13–38weeks of gestation). Fetal cardiac anatomy was assessed and measurements of cardiac structures were performed on T2-weighted 3D multiplanar reconstructed images. Linear regression analysis was performed to examine changes of cardiac dimensions during gestation. Results The four-chamber view of the fetal heart could be obtained and the measurements of cardiac chambers and ventricular walls could be performed in all 39 cases. The aorta and the pulmonary artery were visualized and their diameters were measured in 38 (97.4%) fetuses, ductus arteriosus in 32 (82%). All measurements showed strong linear correlation with gestational age. The relationship of the diameters of the pulmonary artery, aorta, and ductus arteriosus remained constant over pregnancy. All these observations are consistent with what is known from prenatal ultrasound. Conclusions The present study proves the feasibility of visualizing normal cardiac structures on 3-tesla pmMRI in fetuses beyond 14weeks. We provide morphometric data that may enable diagnostic evaluation of cardiac abnormalities on pmMRI. © 2013 John Wiley & Sons, Ltd.
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- 2013
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16. Prenatal diagnosis of MPPH syndrome
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Filip Claus, Luc De Catte, Philippe Moerman, Hilde Van Esch, Dominique Van Schoubroeck, and Bart De Keersmaecker
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Fetus ,medicine.medical_specialty ,Pathology ,Polydactyly ,business.industry ,Obstetrics and Gynecology ,Prenatal diagnosis ,medicine.disease ,Endocrinology ,Recessive inheritance ,MPPH syndrome ,Internal medicine ,medicine ,Etiology ,Polymicrogyria ,Megalencephaly ,business ,Genetics (clinical) - Abstract
We report the prenatal sonographic detection of a fetus with megalencephaly, polymicrogyria, postaxial polydactyly and hydrocephaly. Only 14 patients have been reported in the literature so far, all but one were diagnosed postnatally. The polymicrogyria in the frontoparietal lobe was confirmed by prenatal magnetic resonance imaging. Additionally, a hypoplastic thymus as seen in a 22q11 deletion was present. Although polymicrogyria along with pre-axial polydactyly has been described in 22q11 deletion, the diagnosis of Di George syndrome was ruled out. The etiology of megalencephaly, polymicrogyria, postaxial polydactyly and hydrocephaly has not been revealed yet. A dominant as well as recessive inheritance has been suggested. © 2013 John Wiley & Sons, Ltd.
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- 2013
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17. Postmortem High-Resolution Fetal Magnetic Resonance Imaging in Three Cases of Lower Urinary Tract Obstruction
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An Hindryckx, Philippe Moerman, Filip Claus, Luc De Catte, Mathieu Lefere, Roland Devlieger, and Inga Sandaite
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Adult ,Embryology ,medicine.medical_specialty ,Urethral Obstruction ,Urinary system ,Prenatal Diagnosis ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Urinary Tract ,Pregnancy ,medicine.diagnostic_test ,business.industry ,Obstetrics and Gynecology ,Magnetic resonance imaging ,General Medicine ,Megacystis ,medicine.disease ,Magnetic Resonance Imaging ,Surgery ,Urethral atresia ,Fetal Diseases ,Pediatrics, Perinatology and Child Health ,Female ,Radiology ,Presentation (obstetrics) ,business ,Urinary tract obstruction ,Urethral valve - Abstract
In this manuscript we report 3 cases of severe lower urinary tract obstruction diagnosed before 20 weeks of pregnancy. All cases had a very similar prenatal presentation with a megacystis, bilateral hydro-ureteronephrosis and increased echogenicity of the kidneys. High-resolution postmortem magnetic resonance imaging (MRI), following termination of pregnancy, enabled accurate investigation of the underlying cause of the urinary tract obstruction, by depicting the presence of an urethral valve, urethral atresia and cloacal dysgenesis. Postmortem fetal MRI provides high anatomical detail and is very suitable to investigate congenital anomalies of the lower urinary tract. In case (timely or consented) conventional autopsy is not possible, MRI is an excellent alternative.
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- 2013
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18. Ischemic Strangulation of a Giant Epiploic Appendage through an Omental Defect: a Case Report
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Filip Claus, Tine Hulstaert, Lieven Van Hoe, Marc Krick, Olivier Bladt, An Verena Lerut, and Faculty of Medicine and Pharmacy
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lcsh:Medical physics. Medical radiology. Nuclear medicine ,medicine.medical_specialty ,Abdominal pain ,lcsh:R895-920 ,Case Report ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,Total colonoscopy ,0302 clinical medicine ,Rare case ,Abdomen ,medicine ,Epiploic appendagitis ,business.industry ,Epiploic appendage ,Colonic wall ,medicine.disease ,Surgery ,medicine.anatomical_structure ,030220 oncology & carcinogenesis ,Transomental herniation ,Radiology ,medicine.symptom ,business - Abstract
We report a rare case of an epiploic appendage twisted through an omental defect, resulting in an epiploic appendagitis at a distance to the colonic wall. The 59-year-old women complained of low abdominal pain and alguria, progressively increasing following a total colonoscopy 4 days earlier.
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- 2016
19. Less Common Causes of Acute Abdomen
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Filip Claus, Piet Vanhoenacker, and Lieven Van Hoe
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lcsh:Medical physics. Medical radiology. Nuclear medicine ,medicine.medical_specialty ,business.industry ,lcsh:R895-920 ,Cecum ,medicine.anatomical_structure ,Acute abdomen ,Acute appendicitis ,medicine ,Duodenum ,In patient ,Radiology ,medicine.symptom ,Presentation (obstetrics) ,Superior mesenteric vein ,Mesentery ,business ,Abstract - Abstract
In this presentation, less common causes of acute abdomen are reviewed. Emphasis is on three topics. First, the anatomy of the superior mesenteric vein and mesentery is reviewed, together with the anatomical basis and clinical/radiological presentation of midgut volvulus. Emphasis is on diagnostic clues (whirl sign, abnormal position of cecum, small bowel, and third part of duodenum) and pitfalls (positional variation of small bowel loops with pseudo-twisting of mesenteric vessels). Second, atypical presentations of acute appendicitis and appendagitis, as well as their mimics, are discussed. Finally, an overview is given of uncommon but important causes of free intraperitoneal fluid in patients with acute abdominal pain.
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- 2016
20. Correlation of free-response and receiver-operating-characteristic area-under-the-curve estimates: Results from independently conducted FROC/ROC studies in mammography
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Valerie Celis, Hong-Jun Yoon, Chantal Van Ongeval, Federica Zanca, Filip Claus, Stephen L. Hillis, Veerle Provoost, and Hilde Bosmans
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medicine.diagnostic_test ,Receiver operating characteristic ,Area under the curve ,Nonparametric statistics ,General Medicine ,Pearson product-moment correlation coefficient ,Confidence interval ,Correlation ,symbols.namesake ,Standard error ,Statistics ,symbols ,medicine ,Mammography ,Mathematics - Abstract
Purpose: From independently conducted free-response receiver operating characteristic (FROC) and receiver operating characteristic (ROC) experiments, to study fixed-reader associations between three estimators: the area under the alternative FROC (AFROC) curve computed from FROC data, the area under the ROC curve computed from FROC highest rating data, and the area under the ROC curve computed from confidence-of-disease ratings. Methods: Two hundred mammograms, 100 of which were abnormal, were processed by two image-processing algorithms and interpreted by four radiologists under the FROC paradigm. From the FROC data, inferred-ROC data were derived, using the highest rating assumption. Eighteen months afterwards, the images were interpreted by the same radiologists under the conventional ROC paradigm; conventional-ROC data (in contrast to inferred-ROC data) were obtained. FROC and ROC (inferred, conventional) data were analyzed using the nonparametric area-under-the-curve (AUC), (AFROC and ROC curve, respectively). Pearson correlation was used to quantify the degree of association between the modality-specific AUC indices and standard errors were computed using the bootstrap-after-bootstrap method. The magnitude of the correlations was assessed by comparison with computed Obuchowski-Rockette fixed reader correlations. Results: Average Pearson correlations (with 95% confidence intervals in square brackets) were: Corr(FROC, inferred ROC) = 0.76[0.64, 0.84] > Corr(inferred ROC, conventional ROC) =more » 0.40[0.18, 0.58] > Corr (FROC, conventional ROC) = 0.32[0.16, 0.46]. Conclusions: Correlation between FROC and inferred-ROC data AUC estimates was high. Correlation between inferred- and conventional-ROC AUC was similar to the correlation between two modalities for a single reader using one estimation method, suggesting that the highest rating assumption might be questionable.« less
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- 2012
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21. Prenatal Neurologic Anomalies
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Filip Claus, Luc De Catte, and Bart De Keersmaeker
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medicine.medical_specialty ,Microcephaly ,Pathology ,Prenatal diagnosis ,Nervous System Malformations ,Ultrasonography, Prenatal ,Corpus Callosum ,Pregnancy ,medicine ,Humans ,Abnormalities, Multiple ,Pharmacology (medical) ,3D ultrasound ,Cyst ,Neural Tube Defects ,Fetus ,medicine.diagnostic_test ,Cysts ,business.industry ,Vascular malformation ,Brain ,medicine.disease ,Hypoplasia ,Agenesis ,Pediatrics, Perinatology and Child Health ,Female ,Radiology ,Agenesis of Corpus Callosum ,Dandy-Walker Syndrome ,business ,Hydrocephalus - Abstract
The low prevalence of fetal CNS anomalies results in a restricted level of exposure to, and limited experience for most obstetricians involved in, prenatal ultrasound. Sonographic guidelines for screening the fetal brain in a systematic way may increase the detection rate of fetal CNS anomalies, thus promoting correct referral to tertiary care centers offering patients a multidisciplinary approach to the condition. The aim of this review is to elaborate on the prenatal sonographic diagnosis and outcome of various CNS malformations. Detailed neurosonographic investigation has become available through high-resolution vaginal ultrasound probes and the development of a variety of 3-dimensional (3D) ultrasound modalities, such as ultrasound tomographic imaging. In addition, fetal magnetic resonance imaging is particularly helpful in the detection of gyration and neurulation anomalies, and disorders of the gray and white matter. Isolated mild ventriculomegaly is a rather common finding with good overall outcome. With an increasing diameter of the atria, however, and especially with the presence of associated malformations, long-term neurodevelopmental and behavioral outcome is disturbed in about 15% or more of cases. In view of recent developments in fetal therapy for neural tube defects, there is a clear need for a high level of ultrasound screening, work-up and counseling in tertiary care centers to identify those cases that might benefit from in utero intervention. The failure of prosencephalic midline induction and development results in midline defects ranging from alobar holoprosencephaly to isolated corpus callosum defects. The detection of callosal abnormaties is enhanced by 3D ultrasound, but counseling on neurodevelopmental outcome remains challenging. The Dandy-Walker spectrum includes isolated megacisterna magna, Blake's pouch cyst, hypoplasia of the vermis and Dandy-Walker malformation. Except for complete agenesis of the vermis associated with fourth ventricle cyst formation, data on long-term outcomes for the various conditions is largely lacking. Congenital cytomegalovirus (CMV) results in the highest incidence of children born with, or developing, long-term neurologic conditions. If proof of fetal infection has been delivered, microcephaly, cortical malformations, and intraparenchymal cysts show a strong correlation with poor outcome. Fetuses with CMV-related ultrasound abnormalities might benefit from maternal transplacental treatment. The aneurysm of the vein of Galen, a vascular malformation of the brain, often results in high cardiac output failure. After neonatal arterial embolization, survival is about 50% with normal neurologic development in 36% of cases. Over 50% of intracranial tumors are teratomata, presenting as fast-growing heterogeneous solid-cystic masses with calcifications. Most intracranial hemorrhages are related to the ventricular system, and prognosis is often poor, particularly in cases involving parenchymal and subdural bleeding. Proliferation disorders of the brain are often characterized by microcephaly. Their etiology is heterogeneous and prenatal diagnosis is often made late in gestation.
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- 2012
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22. The correlation between lung volume and liver herniation measurements by fetal MRI in isolated congenital diaphragmatic hernia: a systematic review and meta-analysis of observational studies
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Inga Sandaite, Holger Till, Jan Deprest, Steffi Mayer, Filip Claus, Elisa Done, Philipp Klaritsch, and Scott Petersen
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Adult ,medicine.medical_specialty ,Birth weight ,Diaphragmatic breathing ,Fetus ,Pregnancy ,Prenatal Diagnosis ,medicine ,Humans ,Abnormalities, Multiple ,Lung volumes ,Lung ,Survival rate ,Genetics (clinical) ,Hernia, Diaphragmatic ,medicine.diagnostic_test ,business.industry ,Obstetrics and Gynecology ,Congenital diaphragmatic hernia ,Gestational age ,Magnetic resonance imaging ,Odds ratio ,medicine.disease ,Magnetic Resonance Imaging ,Surgery ,Survival Rate ,Fetal Diseases ,Liver ,Female ,Hernias, Diaphragmatic, Congenital ,Lung Volume Measurements ,business ,Nuclear medicine - Abstract
Objective We conducted a meta-analysis to assess the correlation of lung volume and liver position measured by magnetic resonance imaging (MRI) with survival until discharge in fetuses with isolated congenital diaphragmatic hernia (CDH). Method Systematic searches of MEDLINE and EMBASE from 1 January 1980 to 10 December 2010 were performed. Studies correlating total fetal lung volumes (TFLV, observed/expected (O/E) TFLV) and/or liver position by fetal MRI to survival in expectantly managed fetuses with CDH were included. Data on the side of the defect, position of the liver, TFLV, O/E TFLV, gestational age (GA) at MRI, GA and weight at birth were collected. Odds ratio (OR) for dichotomous data, mean differences (MD) or standardized mean differences (SMD) for continuous variables were determined using RevMan 5.0 software. Results Nineteen studies (n = 602 fetuses) were included. Survival was associated with left-sided defects (OR 2.52; p = 0.01), “liver down” (OR 0.18; p
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- 2011
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23. Prenatal assessment and management of sacrococcygeal teratoma
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Anne Uyttebroek, Filip Claus, Marleen Renard, Leonardo Gucciardo, Luc De Catte, Jan Deprest, Ivo De Wever, Roland Devlieger, and Liesbeth Lewi
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education.field_of_study ,medicine.medical_specialty ,Obstetrics ,Fetal surgery ,business.industry ,medicine.medical_treatment ,Population ,Obstetrics and Gynecology ,Prenatal diagnosis ,Prenatal care ,medicine.disease ,Malignancy ,Fetal intervention ,medicine ,Teratoma ,education ,Sacrococcygeal teratoma ,business ,Genetics (clinical) - Abstract
Sacrococcygeal teratoma (SCT) is one of the most common tumors in newborns with a birth prevalence of up to 1 in 21,700 births. Routine fetal anomaly screening programs allow for prenatal diagnosis in many cases. Fetal ultrasound with Doppler evaluation and more recently magnetic resonance imaging may be used to document the extent of the tumor as well as identifying the population at risk for serious fetal complications. Rapidly growing SCT and highly vascularized tumors are more likely to have hemodynamic repercussions. Fetal hydrops is usually considered as a poor prognostic marker and a potential indicator for fetal intervention. Newborns with SCT require stabilization prior to early surgical resection. In case of malignancy additional chemotherapy may be required. SCT may result in significant morbidity, either directly or as a consequence of surgical therapy. Careful postnatal follow-up is required for timely identification and treatment of complications as well as recurrence. This paper aims to review the perinatal management of this condition.
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- 2011
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24. Prenatal Anatomical Imaging in Fetuses with Congenital Diaphragmatic Hernia
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Leonardo Gucciardo, Rogelio Cruz Martinez, Philip DeKoninck, Tim Van Mieghem, Eduard Gratacós, Filip Claus, O. Moreno, Inga Sandaite, Katrijn Michielsen, Jan Deprest, Jonas Decraene, Jute Richter, Roland Devlieger, Surgical clinical sciences, and Mother and Child
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Embryology ,medicine.medical_specialty ,Diaphragmatic breathing ,Ultrasonography, Prenatal ,lung ,Diagnosis, Differential ,Fetal Development ,Fetoscopy ,Pulmonary hypoplasia ,medicine ,Humans ,magnetic resonance imaging ,Radiology, Nuclear Medicine and imaging ,Diaphragmatic hernia ,Hernia ,Hernia, Diaphragmatic ,medicine.diagnostic_test ,business.industry ,Obstetrics and Gynecology ,Congenital diaphragmatic hernia ,Magnetic resonance imaging ,General Medicine ,Prognosis ,medicine.disease ,Hypoplasia ,Surgery ,Trachea ,fetus ,Pediatrics, Perinatology and Child Health ,Radiology ,Hernias, Diaphragmatic, Congenital ,business - Abstract
The role of prenatal ultrasound and magnetic resonance imaging in the diagnosis and management of congenital diaphragmatic hernia (CDH) is reviewed. Topics include morphologic imaging and vascular assessment of the developing lung, the value of imaging parameters as prognostic predictors in CDH and the role of imaging following percutaneous fetoscopic endoluminal tracheal occlusion.
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- 2010
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25. Cross-sectional Study of Tracheomegaly in Children after Fetal Tracheal Occlusion for Severe Congenital Diaphragmatic Hernia
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Maria-Helena Smet, Anne Debeer, Paul Lewi, Marijke Proesmans, Filip Claus, Jan Deprest, Karel Allegaert, Frederik De Keyzer, and Luc Breysem
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Male ,medicine.medical_specialty ,Tracheomegaly ,Statistics, Nonparametric ,Fetoscopy ,Occlusion ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Diaphragmatic hernia ,Child ,Hernia, Diaphragmatic ,Pregnancy ,medicine.diagnostic_test ,business.industry ,Respiratory disease ,Infant, Newborn ,Infant ,Congenital diaphragmatic hernia ,Balloon Occlusion ,respiratory system ,medicine.disease ,Surgery ,Trachea ,Cross-Sectional Studies ,Treatment Outcome ,Child, Preschool ,Regression Analysis ,Female ,Hernias, Diaphragmatic, Congenital ,Tomography, X-Ray Computed ,Complication ,business - Abstract
To measure tracheal dimensions in children with congenital diaphragmatic hernia (CDH) who had undergone fetoscopic endoluminal tracheal occlusion (FETO) or were treated expectantly during gestation.The study was approved by the local ethics committee. Computed tomography was performed in 23 patients (14 boys and nine girls) aged 1 month to 6.5 years, and the anteroposterior diameter, width, area, and perimeter of the trachea were determined. Seven of the 23 patients had undergone FETO and 16 had been treated expectantly. The relative difference of each parameter between the two most proximal concentric sections of the trachea, just below the larynx, and the two sections on which the trachea was the largest was compared between both groups (Mann-Whitney U test). Regression statistics were applied to maximum and mean tracheal areas as a function of age. Each trachea was divided into quartiles, and mean areas normalized to 3 years of age were analyzed for each quartile as a function of its relative position on the trachea (Student t test).Tracheal width, area, and perimeter were significantly different between both groups. A linear relationship was observed between the maximum and mean tracheal areas and age for both the FETO group (maximum tracheal area: R(2) = 0.83, P = .0045; mean tracheal area: R(2) = 0.92, P = .0005) and the non-FETO group (maximum tracheal area: R(2) = 0.66, P = .0001; mean trachea area: R(2) = 0.66, P = .0001). The maximum tracheal area in both groups tended to decrease toward the age of 5 years. Significantly different mean tracheal areas per tracheal quartile (P.05) were found for all quartiles except for the proximal one-fourth.The relative difference between proximal and largest tracheal width, area, and perimeter was significantly larger in patients who underwent FETO than in those treated expectantly, demonstrating tracheal dilatation in the former. Measurements of tracheal dimensions at different levels indicate a maximum dilatation in the lower half of the trachea, which tends to level off toward the age of 5 years.
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- 2010
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26. Tracheal side effects following fetal endoscopic tracheal occlusion for severe congenital diaphragmatic hernia
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E. Gratacós, Jan Deprest, Pierre Fayoux, Anne Debeer, Kypros H. Nicolaides, Maria Helena Smet, Marijke Proesmans, Filip Claus, Laurent Storme, and Luc Breysem
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Male ,medicine.medical_specialty ,Percutaneous ,medicine.medical_treatment ,Pulmonary hypoplasia ,Tracheotomy ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Hernia ,Tracheobronchomegaly ,Hysterotomy ,Survival rate ,Hernia, Diaphragmatic ,Lung ,business.industry ,Congenital diaphragmatic hernia ,Endoscopy ,medicine.disease ,Surgery ,Radiography ,Fetal Diseases ,Treatment Outcome ,medicine.anatomical_structure ,Anesthesia ,Pediatrics, Perinatology and Child Health ,Female ,business - Abstract
Despite optimal neonatal care and even in large referral centres, between 20% and 30% of neonates with isolated congenital diaphragmatic hernia (CDH) will not survive [1]. The leading causes of death remain in essence pulmonary hypoplasia and persistent pulmonary hypertension (PPHT). Prenatal medical imaging methods are used to predict individual outcome, which provides parents with prenatal options. For those with a predicted poor outcome this might include prenatal intervention, which aims to improve lung development rather than repairing the anatomical defect. Early attempts by prenatal surgical repair of the defect were abandoned as they required access by hysterotomy and because reducing liver herniation compromises the fetal circulation [2]. Tracheal occlusion (TO) prevents egress of lung liquid produced by the airway epithelium, hence induces tissue stretch, which acts as a signal for lung growth [3, 4]. Clinically TO was initially performed using extra-luminal clips with reversal during an ex-utero intrapartum tracheoplasty procedure [5]. Subsequently an endoluminal balloon was used, which allows easier reversal in utero, that itself triggers lung maturation according to experimental evidence [5–7]. Invasiveness was further reduced by using a completely percutaneous approach, small diameter instruments with a move towards regional or local anaesthesia. Up to 2008 the FETO consortium performed more than 200 percutaneous fetoscopic endoluminal TOs (FETO) [8]. Survival rate is twice as high as predicted, the latter based on lung size measurements in case of left-sided CDH [9]. Obviously this data is based on external controls and the procedure should be considered as investigational whilst a trial has not confirmed these early findings [10].
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- 2010
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27. Evaluation of clinical image processing algorithms used in digital mammography
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Chantal Van Ongeval, Valerie Celis, Filip Claus, Herman Pauwels, Catherine Geniets, Veerle Provost, Federica Zanca, Jurgen Jacobs, Guy Marchal, and Hilde Bosmans
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medicine.medical_specialty ,Digital mammography ,medicine.diagnostic_test ,Receiver operating characteristic ,Breast imaging ,Screening mammography ,business.industry ,Computer science ,Image quality ,Cancer ,Image processing ,Pattern recognition ,General Medicine ,medicine.disease ,Breast cancer ,Calcinosis ,Digital image processing ,Medical imaging ,medicine ,Mammography ,Radiographic Image Enhancement ,Artificial intelligence ,Radiology ,business - Abstract
Screening is the only proven approach to reduce the mortality of breast cancer, but significant numbers of breast cancers remain undetected even when all quality assurance guidelines are implemented. With the increasing adoption of digital mammography systems, image processing may be a key factor in the imaging chain. Although to our knowledge statistically significant effects of manufacturer-recommended image processings have not been previously demonstrated, the subjective experience of our radiologists, that the apparent image quality can vary considerably between different algorithms, motivated this study. This article addresses the impact of five such algorithms on the detection of clusters of microcalcifications. A database of unprocessed (raw) images of 200 normal digital mammograms, acquired with the Siemens Novation DR, was collected retrospectively. Realistic simulated microcalcification clusters were inserted in half of the unprocessed images. All unprocessed images were subsequently processed with five manufacturer-recommended image processing algorithms (Agfa Musica 1, IMS Raffaello Mammo 1.2, Sectra Mamea AB Sigmoid, Siemens OPVIEW v2, and Siemens OPVIEW v1). Four breast imaging radiologists were asked to locate and score the clusters in each image on a five point rating scale. The free-response data were analyzed by the jackknife free-response receiver operating characteristic (JAFROC) method and, for comparison, also with the receiver operating characteristic (ROC) method. JAFROC analysis revealed highly significant differences between the image processings (F = 8.51, p < 0.0001), suggesting that image processing strongly impacts the detectability of clusters. Siemens OPVIEW2 and Siemens OPVIEW1 yielded the highest and lowest performances, respectively. ROC analysis of the data also revealed significant differences between the processing but at lower significance (F = 3.47, p = 0.0305) than JAFROC. Both statistical analysis methods revealed that the same six pairs of modalities were significantly different, but the JAFROC confidence intervals were about 32% smaller than ROC confidence intervals. This study shows that image processing has a significant impact on the detection of microcalcifications in digital mammograms. Objective measurements, such as described here, should be used by the manufacturers to select the optimal image processing algorithm.
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- 2009
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28. Clinical Challenges and Images in GI
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Filip Claus, André D'Hoore, and Karel Geboes
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medicine.medical_specialty ,Pathology ,Leiomyomatosis ,medicine.anatomical_structure ,Hepatology ,medicine.diagnostic_test ,business.industry ,Gastroenterology ,medicine ,Rectum ,Magnetic resonance imaging ,Radiology ,business - Published
- 2008
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29. An improved method for simulating microcalcifications in digital mammograms
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Jurgen Jacobs, Chantal Van Ongeval, Filip Claus, Hilde Bosmans, Federica Zanca, Dev P. Chakraborty, and Guy Marchal
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medicine.medical_specialty ,Digital mammography ,medicine.diagnostic_test ,business.industry ,Image processing ,Pattern recognition ,General Medicine ,Digital image ,Medical imaging ,Imaging technology ,Medicine ,Mammography ,Radiology ,Artificial intelligence ,Microcalcification ,Image sensor ,medicine.symptom ,business - Abstract
The assessment of the performance of a digital mammography system requires an observer study with a relatively large number of cases with known truth which is often difficult to assemble. Several investigators have developed methods for generating hybrid abnormal images containing simulated microcalcifications. This article addresses some of the limitations of earlier methods. The new method is based on digital images of needle biopsy specimens. Since the specimens are imaged separately from the breast, the microcalcification attenuation profile scan is deduced without the effects of over and underlying tissues. The resulting templates are normalized for image acquisition specific parameters and reprocessed to simulate microcalcifications appropriate to other imaging systems, with different x-ray, detector and image processing parameters than the original acquisition system. This capability is not shared by previous simulation methods that have relied on extracting microcalcifications from breast images. The method was validated by five experienced mammographers who compared 59 pairs of simulated and real microcalcifications in a two-alternative forced choice task designed to test if they could distinguish the real from the simulated lesions. They also classified the shapes of the microcalcifications according to a standardized clinical lexicon. The observed probability of correct choice was 0.415, 95% confidencemore » interval (0.284, 0.546), showing that the radiologists were unable to distinguish the lesions. The shape classification revealed substantial agreement with the truth (mean kappa=0.70), showing that we were able to accurately simulate the lesion morphology. While currently limited to single microcalcifications, the method is extensible to more complex clusters of microcalcifications and to three-dimensional images. It can be used to objectively assess an imaging technology, especially with respect to its ability to adequately visualize the morphology of the lesions, which is a critical factor in the benign versus malignant classification of a lesion detected in screening mammography.« less
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- 2008
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30. In vivo evidence by magnetic resonance volumetry of a gestational age dependent response to tracheal occlusion for congenital diaphragmatic hernia
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Katika, Nawapun, Mary Patrice, Eastwood, Daysi, Diaz-Cobos, Julio, Jimenez, Michael, Aertsen, Olga, Gomez, Filip, Claus, Eduard, Gratacós, and Jan, Deprest
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Adult ,Fetal Therapies ,Gestational Age ,Organ Size ,Magnetic Resonance Imaging ,Trachea ,Fetus ,Liver ,Pregnancy ,Case-Control Studies ,Prenatal Diagnosis ,Disease Progression ,Linear Models ,Humans ,Female ,Prospective Studies ,Hernias, Diaphragmatic, Congenital ,Watchful Waiting ,Lung - Abstract
We aimed to assess in vivo changes in lung and liver volumes in fetuses with isolated congenital diaphragmatic hernia, either expectantly managed or treated in utero.This is a secondary analysis of prospectively collected data at two fetal therapy centers. We used archived magnetic resonance images of fetuses taken ≥7 days apart, creating paired observations in 20 expectantly managed cases, 41 with a second magnetic resonance prior to balloon reversal and 64 after balloon removal. We measured observed to expected total fetal lung volume (O/E TFLV) and liver-to-thoracic volume ratio. We calculated changes in volume as compared with the initial measurement and its rate as a function of gestational age (GA) at occlusion.The liver-to-thoracic volume ratio did not change in either group. In expectantly managed fetuses, O/E TFLV did not increase with gestation. In fetuses undergoing tracheal occlusion, the measured increase in volume was 2.6 times larger with balloon in place as compared with that after its removal. GA at tracheal occlusion was an independent predictor of the O/E TFLV. The net rate seems to initially increase and plateau at a maximum of 1.5% per week by 35 to 45 days after occlusion.Tracheal occlusion induces a net increase in volume, its magnitude essentially dependent on the GA at occlusion.
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- 2015
31. Three-dimensional analysis of implanted magnetic-resonance-visible meshes
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Jan D'hooge, Frederik De Keyzer, Geertje Callewaert, Filip Claus, Andrew Feola, Sebastien Ourselin, Nikhil Sindhwani, Jan Deprest, and Iva Urbankova
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Semiautomatic segmentation ,Three dimensional analysis ,medicine.medical_specialty ,medicine.diagnostic_test ,business.industry ,Urology ,Antenna aperture ,Obstetrics and Gynecology ,3d model ,Magnetic resonance imaging ,Surgical Mesh ,Magnetic Resonance Imaging ,Surgery ,Workflow ,Imaging, Three-Dimensional ,Position (vector) ,medicine ,Humans ,Polygon mesh ,Female ,Mr images ,business ,Algorithms ,Biomedical engineering - Abstract
Our primary objective was to develop relevant algorithms for quantification of mesh position and 3D shape in magnetic resonance (MR) images. In this proof-of-principle study, one patient with severe anterior vaginal wall prolapse was implanted with an MR-visible mesh. High-resolution MR images of the pelvis were acquired 6 weeks and 8 months postsurgery. 3D models were created using semiautomatic segmentation techniques. Conformational changes were recorded quantitatively using part-comparison analysis. An ellipticity measure is proposed to record longitudinal conformational changes in the mesh arms. The surface that is the effective reinforcement provided by the mesh is calculated using a novel methodology. The area of this surface is the effective support area (ESA). MR-visible mesh was clearly outlined in the images, which allowed us to longitudinally quantify mesh configuration between 6 weeks and 8 months after implantation. No significant changes were found in mesh position, effective support area, conformation of the mesh’s main body, and arm length during the period of observation. Ellipticity profiles show longitudinal conformational changes in posterior arms. This paper proposes novel methodologies for a systematic 3D assessment of the position and morphology of MR-visible meshes. A novel semiautomatic tool was developed to calculate the effective area of support provided by the mesh, a potentially clinically important parameter.
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- 2015
32. Gustatory Stimulation Changes the Apparent Diffusion Coefficient of Salivary Glands: Initial Experience
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Robert Hermans, Frederik De Keyzer, Stefan Sunaert, Filip Claus, and Harriet C. Thoeny
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Adult ,Male ,Saliva ,Submandibular Gland ,Stimulation ,Ascorbic Acid ,Sensitivity and Specificity ,stomatognathic system ,Reference Values ,Image Processing, Computer-Assisted ,medicine ,Humans ,Parotid Gland ,Radiology, Nuclear Medicine and imaging ,Prospective Studies ,Volunteer ,medicine.diagnostic_test ,Salivary gland ,Echo-Planar Imaging ,business.industry ,Magnetic resonance imaging ,Ascorbic acid ,Submandibular gland ,Parotid gland ,Diffusion Magnetic Resonance Imaging ,medicine.anatomical_structure ,Taste ,Female ,Salivation ,Nuclear medicine ,business - Abstract
Echo-planar diffusion-weighted (DW) magnetic resonance (MR) imaging was used to evaluate changes in the parotid glands during gustatory stimulation. The study protocol was approved by the local ethics committee, and informed consent was obtained from all volunteers. Twelve healthy volunteers (five women, seven men) with a median age of 25 years (range, 22-30 years) were examined with a 1.5-T MR unit. A DW MR imaging sequence was performed once at rest and continuously repeated over a mean period of 26 minutes (range, 24-28 minutes) during salivary stimulation with a tablet of ascorbic acid given orally. During the first 5 minutes (range, 1 minute 30 seconds--7 minutes 30 seconds) of salivary stimulation, a decrease in apparent diffusion coefficient (ADC) was observed in both the parotid (P = .0001) and the submandibular (P = .0004) glands in all volunteers. During the following 15 minutes, a steady increase in ADC from the baseline value was noted for the parotid glands (P = .0022), and peak ADC was reached a median of 21 minutes (range, 14-21 minutes) after the start of gustatory stimulation. The ADC of the submandibular glands did not increase significantly after the start of gustatory stimulation compared with the ADC at baseline. In conclusion, DW MR imaging allows physicians to noninvasively demonstrate functional changes in the salivary glands.
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- 2005
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33. Report of a Study on IMRT Planning Strategies for Ethmoid Sinus Cancer
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Holger Wirtz, Wilfried De Neve, Ben J. Mijnheer, Coen R.N. Rasch, Hoonsik Bae, Filip Claus, Lai Wan Dora Kwong, Cordelia Hoinkis, Thomas Bortfeld, Werner De Gersem, Byung Chul Cho, Benedick A. Fraass, Karin Muller, and Other departments
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Male ,medicine.medical_specialty ,medicine.medical_treatment ,Planning target volume ,Adenocarcinoma ,Ethmoid Sinus ,Ethmoid sinus ,Imrt planning ,otorhinolaryngologic diseases ,Humans ,Medicine ,Radiology, Nuclear Medicine and imaging ,Medical physics ,Head and neck ,Radiation treatment planning ,neoplasms ,Neoplasm Staging ,business.industry ,Cancer case ,Radiotherapy Planning, Computer-Assisted ,Reproducibility of Results ,Cancer ,Middle Aged ,medicine.disease ,Combined Modality Therapy ,Radiation therapy ,medicine.anatomical_structure ,Oncology ,Radiotherapy, Adjuvant ,Radiotherapy, Conformal ,business ,therapeutics ,Paranasal Sinus Neoplasms - Abstract
Aim: This communication reviews the planning strategies and dose statistics of nine IMRT plans generated for a complex head and neck case. Patient and Method: An ethmoid sinus cancer case was sent as an IMRT planning task to all participants of the ESTRO course on “IMRT and Other Conformal Techniques in Practice”, held in Amsterdam in June 2001. Results: Nine IMRT plans were generated for the case, the majority of the plans generated with commercial planning systems. The number of beam incidences ranged between four and eleven, while five of the nine beam setups were coplanar. The planning target volume dose homogeneity was inversely correlated with the degree of sparing of the surrounding organs at risk. Conclusion: IMRT strategies for complex head and neck cases, such as ethmoid sinus cancer, can be strikingly different in various aspects, such as beam setup, total number of segments, PTV dose coverage and dose statistics for organs at risks.
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- 2002
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34. Termination of pregnancy for renal malformations
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Filip Claus, An Hindryckx, Philippe Moerman, Eva Simoens, and Luc De Catte
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Nephrology ,Urologic Diseases ,medicine.medical_specialty ,Prenatal diagnosis ,Outcome assessment ,Abortion ,urologic and male genital diseases ,Ultrasonography, Prenatal ,Prenatal ultrasound ,Pregnancy ,Internal medicine ,Germany ,Prenatal Diagnosis ,Outcome Assessment, Health Care ,medicine ,Humans ,Prospective Studies ,Prospective cohort study ,Gynecology ,business.industry ,Obstetrics ,medicine.disease ,Magnetic Resonance Imaging ,Fetal Diseases ,Urogenital Abnormalities ,Pediatrics, Perinatology and Child Health ,Aborted Fetus ,Female ,Autopsy ,Ultrasonography ,business ,Abortion, Eugenic - Abstract
We studied the correlation between prenatal diagnosis and postmortem investigations in pregnancies terminated for renal malformations.Over a 5-year period, 77 cases of termination of pregnancy (TOP) for renal malformations were reviewed. Chromosomal anomalies (n = 9) and cases without conventional or virtual autopsy were excluded (n = 15). In 53 cases, prenatal ultrasound diagnosis and conventional autopsy findings were compared. In addition, we compared the accuracy of conventional and virtual autopsy findings in 17 cases.Full agreement was observed in 60.4% (32/53) of cases. In 26.4% (14/53) of the cases, the presence of additional malformations did not alter the final diagnosis. However, in 11.3% (6/53) the final diagnosis was adjusted because of major additional findings. One case showed a total disagreement. Conventional and virtual autopsy were in full agreement in 52.9% (9/17). Postmortem magnetic resonance imaging (MRI) description and detection of malformations was less complete and failed to correctly diagnose 5/17 cases (29.4%). In 17.6% (3/17) of the cases, postmortem MRI revealed malformations not confirmed by conventional autopsy.A high correlation between prenatal ultrasound and postmortem investigations was observed. Conventional autopsy remains the gold standard to reveal additional major and minor malformations, leading to a correct final diagnosis. The added value of virtual necropsy for renal pathology was limited.
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- 2014
35. Right-sided congenital diaphragmatic hernia in a decade of fetal surgery
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Inga Sandaite, Jan Deprest, Philip DeKoninck, Olga Gómez, Eduard Gratacós, Katika Nawapun, Filip Claus, Jute Richter, An Eerdekens, and Jc Ramirez
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medicine.medical_specialty ,Polyhydramnios ,medicine.medical_treatment ,Population ,Ultrasonography, Prenatal ,Pregnancy ,Prenatal Diagnosis ,medicine ,Rupture of membranes ,Humans ,education ,Survival rate ,Lung ,Retrospective Studies ,education.field_of_study ,Fetal surgery ,Obstetrics ,business.industry ,Infant, Newborn ,Obstetrics and Gynecology ,Gestational age ,Congenital diaphragmatic hernia ,medicine.disease ,Magnetic Resonance Imaging ,Surgery ,Fetal Diseases ,Treatment Outcome ,Female ,business ,Hernias, Diaphragmatic, Congenital - Abstract
Objective To report a recent update on fetuses with right-sided congenital diaphragmatic hernia (RCDH) in the era of fetal surgery. Design Retrospective review of prospectively collected data. Setting Fetal treatment centres in Leuven and Barcelona. Population Consecutive cases of RCDH between 2002 and 2012. Methods Data on prenatal imaging, genetic testing, pregnancy and neonatal outcomes were extracted from our databases, including structural and genetic anomalies, candidate outcome predictors such as lung size, liver herniation ratio, polyhydramnios, cervical length, preterm prelabour rupture of membranes and gestational age at birth. Main outcome measures Survival and oxygen dependency at discharge. Results Ten out of 86 fetuses with RCDH had associated abnormalities. Of 76 isolated pregnancies, eight women opted for termination of pregnancy, most with severe hypoplasia and one was lost to follow up. Nineteen pregnancies were expectantly managed and delivered at a mean gestational age of 36.0 ± 3.0 weeks. Survival at discharge was 53% (10/19), one being oxygen dependent. In the fetal surgery group (n = 48), mean gestational age at delivery was 34.5 ± 3.0 weeks. In our recent experience not previously published (n = 23) survival rate was 52 and 39% were oxygen dependent at discharge. Pooling these data with earlier reported observations by our group we observed a 42% survival rate in 57 fetuses. Lung size on magnetic resonance imaging and an interval of >24 hours between reversal of tracheal occlusion and delivery were predictors of outcome. Conclusions Right-sided CDH seems to have a poorer outcome than that reported for fetuses with left-sided CDH with similar lung size before birth. Survival rates after expectant management with observed/expected lung-to-head ratio values ≤45 and ≤30% were 17 and 0%, respectively. In those undergoing fetal surgery (observed/expected lung-to-head ratio ≤45%) there was an apparent increase (42%).
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- 2014
36. Distal intestinal obstruction syndrome
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K Carels and Filip Claus
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lcsh:Medical physics. Medical radiology. Nuclear medicine ,Adult ,medicine.medical_specialty ,Cystic Fibrosis ,lcsh:R895-920 ,Contrast Media ,Cystic fibrosis ,law.invention ,Diagnosis, Differential ,Feces ,law ,Clinical history ,medicine ,Humans ,Exocrine pancreatic insufficiency ,business.industry ,Septic shock ,Bilateral lung transplantation ,Syndrome ,medicine.disease ,Intensive care unit ,Surgery ,Distal intestinal obstruction syndrome ,Radiographic Image Enhancement ,Mucus ,Female ,medicine.symptom ,business ,Tomography, X-Ray Computed ,Pyeloureteral junction ,Intestinal Obstruction - Abstract
A 31-year-old woman with cystic fibrosis (CF) presents with a rightsided obstructive pyeloureteral junction stone complicated by urosepsis. Following an emergency treatment with ureteral stent placement, she is transferred to the intensive care unit for symptoms of septic shock and hemodynamic instability. Her clinical history reveals an exocrine pancreatic insufficiency and bilateral lung transplantation, both related to CF.
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- 2014
37. An isocenter position verification device for electronic portal imaging: physical and dosimetrical characteristics
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J. Schauvliege, Wim Duthoy, Bruno Speleers, Vincent Remouchamps, W. De Neve, Y De Deene, K Van Vaerenbergh, Filip Claus, C. De Wagter, and B Van Duyse
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Diagnostic Imaging ,Medical device ,Radiotherapy ,business.industry ,Isocenter ,Conformal radiotherapy ,Dose distribution ,Gel dosimetry ,Portal imaging ,Oncology ,Position (vector) ,Humans ,Medicine ,Dosimetry ,Radiology, Nuclear Medicine and imaging ,Dose Fractionation, Radiation ,Electronics ,business ,Nuclear medicine ,Biomedical engineering - Abstract
The physical and dosimetrical characteristics of a device, designed to visualize the isocenter position on electronic portal images, were examined. The device, to be mounted on the gantry head of the accelerator, containing five spheric lead markers, was designed in order to visualize the isocenter position on portal images. A quality control device was designed to check the reliability of this technique. The disturbance of the dose distribution by the markers was studied with gel dosimetry. The use of markers resulted in a precise and accurate method to visualize the isocenter on portal images. A maximum underdosage of 11%, due to attenuation by the markers, was observed. The use of markers to visualize the isocenter position on portal images, is a fast and reliable method when analyzing patient setup errors with online electronic portal imaging.
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- 2001
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38. Evaluation of a leaf position optimization tool for intensity modulated radiation therapy of head and neck cancer
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Carlos De Wagter, Filip Claus, Ilse Vanhoutte, Wilfried De Neve, Wim Duthoy, Werner De Gersem, and Vincent Remouchamps
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medicine.medical_specialty ,Nose Neoplasms ,Planning target volume ,Optic chiasm ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Head and neck ,Laryngeal Neoplasms ,business.industry ,Radiotherapy Planning, Computer-Assisted ,Head and neck cancer ,Pharyngeal Neoplasms ,Radiotherapy Dosage ,Hematology ,Intensity-modulated radiation therapy ,medicine.disease ,University hospital ,Surgery ,Multileaf collimator ,medicine.anatomical_structure ,Oncology ,Optic nerve ,Radiotherapy, Conformal ,Nuclear medicine ,business ,Algorithms ,Paranasal Sinus Neoplasms - Abstract
Background and purpose : Since 1996, patients are treated at Ghent University Hospital with a multi-segment technique using MultiLeaf Collimators. The segments were obtained by using the Beam's eye view projections of the planning target volume (PTV) and the organs at risk (OARs), after which the segments weights were optimized. To investigate if optimization of the leaf positions would further improve the intensity modulated radiation therapy (IMRT) plans, a tool optimizing leaf positions and segment weights simultaneously, was developed. This tool is called SOWAT, which is the acronym for segment outline and weight adapting tool. Material and methods : The tool evaluates the effects of changing the position of each collimating leaf of all segments on the value of the objective function. Only changes that improve the value of the objective function are retained. Between December 1999 and January 2001, 30 head and neck patients were treated with IMRT. Two patient groups were distinguished: pharyngeal and laryngeal tumors (n=17) and sinonasal tumors (n=13). A specific set of physical endpoints was evaluated for each group. Dose statistics of the treatment plans without and with SOWAT were analyzed. Results : When using SOWAT for the pharyngeal and laryngeal cases, the PTV dose homogeneity increased with a median of 11% (range 2–27%), while the maximum dose to the spinal cord was decreased for 14 of the 17 patients. In four plans where parotid function preservation was a goal, the parotid mean dose was lower than 26 Gy in one plan without SOWAT, and in four plans with SOWAT. For the sinonasal tumors, the PTV dose homogeneity increased with a median of 7% (range 1–14%). SOWAT lowered the mean dose to 53 of the 63 optic pathway structures (retina, optic nerve and optic chiasm). SOWAT leaves the number of segments unchanged and has little or no effect on the delivery time. Conclusions : SOWAT is a powerful tool to perform the final optimization of IMRT plans, without increasing the complexity of the plan or the delivery time.
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- 2001
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39. Improved delivery efficiency for step and shoot intensity modulated radiotherapy using a fast-tuning magnetron
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C Martens, Filip Claus, and GJ Budgell
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Monitor unit ,Step and shoot ,Time Factors ,Materials science ,Radiological and Ultrasound Technology ,business.industry ,Instrumentation ,Reproducibility of Results ,Linear particle accelerator ,Intensity (physics) ,Magnetics ,Cavity magnetron ,Radiology, Nuclear Medicine and imaging ,Particle Accelerators ,Radiotherapy, Conformal ,Radiometry ,Nuclear medicine ,business ,Radiation treatment planning ,Beam (structure) ,Biomedical engineering - Abstract
The delivery efficiency of step and shoot intensity modulated radiotherapy (IMRT) has been improved by the installation of fast-tuning magnetrons into three travelling wave linear accelerators. The IMRT delivery efficiency and the beam start-up performance have been compared before and after installation. Start-up and inter sub-field times were reduced by an average of 3.0 s. A typical start-up time from depression of the start button to beam on is now around 4 s. Delivery efficiency for a variety of clinical and quality control prescriptions was improved by an average of 30.7% (range 7.4-60.9%), depending on a complex combination of the number of sub-fields, distance moved by leaves and dose rate. For the oldest accelerator (7 years old), dosimetric accuracy was significantly improved for low dose sub-fields. The dose output was within 2% for a 1 monitor unit (MU) sub-field and 1% for a 2 MU sub-field. The two newer accelerators displayed similar or better dose characteristics even before fast-tuning magnetron installation. Beam symmetries and flatnesses were acceptable at all energies and dose rates, and showed no obvious degradation in low dose sub-fields. It is recommended that fast-tuning magnetrons are adopted for accelerators of this design performing step and shoot IMRT.
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- 2001
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40. An implementation strategy for IMRT of ethmoid sinus cancer with bilateral sparing of the optic pathways
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Hubert Vermeersch, Wim Duthoy, Wilfried De Neve, Werner De Gersem, Luc Vakaet, Filip Claus, Carlos De Wagter, Vincent Remouchamps, Robert Van Severen, Bart Van Duyse, Marc Lemmerling, and Ilse Vanhoutte
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Male ,Cancer Research ,medicine.medical_specialty ,medicine.medical_treatment ,Mandible ,Adenocarcinoma ,Radiation Dosage ,Retina ,Ethmoid Sinus ,Ethmoid sinus ,medicine ,Humans ,Parotid Gland ,Radiology, Nuclear Medicine and imaging ,Radiation treatment planning ,Aged ,Carcinoma, Transitional Cell ,Radiation ,business.industry ,Brain ,Optic Nerve ,Radiotherapy Dosage ,Middle Aged ,medicine.disease ,Spinal cord ,Surgery ,Multileaf collimator ,Radiation therapy ,medicine.anatomical_structure ,Spinal Cord ,Oncology ,Optic Chiasm ,Carcinoma, Squamous Cell ,Optic nerve ,Radiology ,Radiotherapy, Conformal ,business ,Binocular vision ,Paranasal Sinus Neoplasms ,Retinopathy - Abstract
Purpose: To develop a protocol for the irradiation of ethmoid sinus cancer, with the aim of sparing binocular vision; of developing a strategy of intensity-modulated radiation therapy (IMRT) planning that produces dose distributions that ( 1 ) are consistent with the protocol prescriptions and ( 2 ) are deliverable by static segmental IMRT techniques within a 15-minute time slot; of fine tuning the implementation strategy to a class solution approach that is sufficiently automated and efficient, allowing routine clinical application; of reporting on the early clinical implementation involving 11 patients between February 1999 and July 2000. Patients and Methods: Eleven consecutive T1–4N0M0 ethmoid sinus cancer patients were enrolled in the study. For Patients 1–8, a first protocol was implemented, defining a planning target volume prescription dose of 60 to 66 Gy in 30–33 fractions and a maximum dose ( Dmax ) of 50 Gy to optic pathway structures and spinal cord and limit of 60 Gy to brainstem. For Patients 9–11, an adapted (now considered mature) protocol was implemented, defining a (planning target volume) prescription dose of 70 Gy in 35 fractions and a Dmax to optic pathway structures and brainstem of 60 Gy and to spinal cord of 50 Gy. Results: The class solution-directed strategy developed during this study reduced the protocol translation process from a few days to about 2 hours of planner time. The mature class solution involved the use of 7 beam incidences (20–37 segments), which could be delivered within a 15-minute time slot. Acute side effects were limited and mild. None of the patients developed dry eye syndrome or other visual disturbances. The follow-up period is too short for detection of retinopathy or optic nerve and chiasm toxicity. Conclusion: Conventional radiotherapy of ethmoid sinus tumors is associated with serious morbidity, including blindness. We hypothesize that IMRT has the potential to save binocular vision. The dose to the optic pathway structures can be reduced selectively by IMRT. Further enrollment of patients and longer follow-up will show whether the level of reduction tested by the clinical protocol is sufficient to save binocular vision. An adaptive strategy of IMRT planning was too inefficient for routine clinical practice. A class solution-directed strategy improved efficiency by eliminating human trial and error during the IMRT planning process.
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- 2001
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41. modulation d'intensité en radiothérapie par collimateur multilame dynamique. Technique et expérience clinique
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S. Derycke, P. Van Houtte, C. De Wagter, Filip Claus, and W. De Neve
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Contouring ,business.industry ,medicine.medical_treatment ,Head and neck cancer ,Mediastinum ,medicine.disease ,Multileaf collimator ,Radiation therapy ,Prostate cancer ,medicine.anatomical_structure ,Oncology ,Prostate ,otorhinolaryngologic diseases ,medicine ,Radiology, Nuclear Medicine and imaging ,business ,Nuclear medicine ,therapeutics ,neoplasms ,Intensity modulation - Abstract
Since early 1997, dynamic multileaf collimators (DMLCs) have been used in our division for intensity modulated radiotherapy (IMRT). We have used IMRT to: irradiate concave targets (head and neck, paraspinal tumors); combine beams with shallow hinge angles (mediastinum, lung tumors); deliver intentionally inhomogeneous dose distributions (prostate, paranasal sinuses, brain tumors). IMRT is now our standard treatment for locoregional relapse (after high-dose radiotherapy) for head and neck cancer and for radical treatment of localized prostate cancer. For a variety of other tumors, conventional 3D-plans are compared with IMRT-plans, the latter being clinically implemented if superior. We developed a geometry based IMRT planning strategy to create assemblies of static intensity modulated (IM)-beams which consist of uniform (unmodulated) segments. By a translator program, segments are combined in a single prescription which allows delivery under computer control. Cost-containment is further improved by automation of the planning. After manual or semi-automated contouring of PTV and the organs at risk, prostate IMRT plans, based on a class solution, are generated and optimized by a computer. IMRT for pharyngeal relapses and most other tumor sites is planned semi-automatically. IMRT replaces gradually conventional treatments in our division. Interesting dose distributions generated by IMRT allow a better sparing of normal tissues with decreased acute and late toxicity, and offer a window for further dose escalation.
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- 1999
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42. Intrarenal resistive index after renal transplantation
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Dirk Kuypers, Raymond Oyen, Yves Vanrenterghem, Diethard Monbaliu, Filip Claus, Line Heylen, Ben Sprangers, Evelyne Lerut, Christoph Metalidis, Bert Bammens, Pieter Evenepoel, Björn Meijers, Jacques Pirenne, Hylke de Jonge, Katrien De Vusser, Kathleen Claes, Liesbeth De Wever, and Maarten Naesens
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Adult ,Graft Rejection ,Male ,medicine.medical_specialty ,Biopsy ,Urology ,Renal function ,Kidney ,Kidney Function Tests ,Postoperative Complications ,Renal Artery ,medicine.artery ,Medicine ,Humans ,Prospective Studies ,Renal artery ,Prospective cohort study ,Kidney transplantation ,Aged ,business.industry ,Hazard ratio ,Graft Survival ,Age Factors ,Ultrasonography, Doppler ,General Medicine ,Middle Aged ,medicine.disease ,Prognosis ,Kidney Transplantation ,Confidence interval ,Surgery ,Transplantation ,surgical procedures, operative ,medicine.anatomical_structure ,Pulsatile Flow ,Vascular resistance ,Female ,Vascular Resistance ,business ,Blood Flow Velocity - Abstract
The intrarenal resistive index is routinely measured in many renal-transplantation centers for assessment of renal-allograft status, although the value of the resistive index remains unclear.In a single-center, prospective study involving 321 renal-allograft recipients, we measured the resistive index at baseline, at the time of protocol-specified renal-allograft biopsies (3, 12, and 24 months after transplantation), and at the time of biopsies performed because of graft dysfunction. A total of 1124 renal-allograft resistive-index measurements were included in the analysis. All patients were followed for at least 4.5 years after transplantation.Allograft recipients with a resistive index of at least 0.80 had higher mortality than those with a resistive index of less than 0.80 at 3, 12, and 24 months after transplantation (hazard ratio, 5.20 [95% confidence interval {CI}, 2.14 to 12.64; P0.001]; 3.46 [95% CI, 1.39 to 8.56; P=0.007]; and 4.12 [95% CI, 1.26 to 13.45; P=0.02], respectively). The need for dialysis did not differ significantly between patients with a resistive index of at least 0.80 and those with a resistive index of less than 0.80 at 3, 12, and 24 months after transplantation (hazard ratio, 1.95 [95% CI, 0.39 to 9.82; P=0.42]; 0.44 [95% CI, 0.05 to 3.72; P=0.45]; and 1.34 [95% CI, 0.20 to 8.82; P=0.76], respectively). At protocol-specified biopsy time points, the resistive index was not associated with renal-allograft histologic features. Older recipient age was the strongest determinant of a higher resistive index (P0.001). At the time of biopsies performed because of graft dysfunction, antibody-mediated rejection or acute tubular necrosis, as compared with normal biopsy results, was associated with a higher resistive index (0.87 ± 0.12 vs. 0.78 ± 0.14 [P=0.05], and 0.86 ± 0.09 vs. 0.78 ± 0.14 [P=0.007], respectively).The resistive index, routinely measured at predefined time points after transplantation, reflects characteristics of the recipient but not those of the graft. (ClinicalTrials.gov number, NCT01879124 .).
- Published
- 2013
43. Imaging issues in maternal critical care
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Susanna I. Lee, Melina Pectasides, and Filip Claus
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medicine.medical_specialty ,Obstetrics ,business.industry ,Reproductive medicine ,Elevated liver enzymes ,Pain management ,Imaging modalities ,Plain radiography ,Obstetrics and gynaecology ,Intensive care ,medicine ,Postpartum sepsis ,Intensive care medicine ,business - Published
- 2013
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44. A pictorial essay on fetal rabbit anatomy using micro-ultrasound and magnetic resonance imaging
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Philip, DeKoninck, Masayuki, Endo, Inga, Sandaite, Jute, Richter, Luc, De Catte, Ben, Van Calster, Jaan, Toelen, Uwe, Himmelreich, Filip, Claus, and Jan, Deprest
- Subjects
Umbilical Veins ,Biometry ,Gestational Age ,Magnetic Resonance Imaging ,Ultrasonography, Prenatal ,Umbilical Arteries ,Fetal Development ,Fetus ,Pregnancy ,Reference Values ,Models, Animal ,Animals ,Female ,Rabbits - Abstract
With this pictorial essay, we aimed to provide gestational age specific reference ranges of relevant fetal structures using micro-ultrasound, as well as its correlation with postmortem MRI and whole body sections.Time-mated pregnant rabbits (n = 24) were assessed once at various gestational ages in the second half of pregnancy (15, 17, 21 to 23, 25 to 28, and 30 to 31 days; term = 31 days). We obtained biometric data, together with Doppler flow patterns in the ductus venosus, umbilical artery and umbilical vein. After euthanasia, micro-ultrasound images were compared with images obtained by 9.4 Tesla MRI and whole body paraffin sections at 15, 23, 26, and 28 days.We constructed biometric normative curves, which showed a significant correlation with gestational age. The pulsatility index (PI) in the umbilical artery decreased with gestation (PI = 5.746-0.2969(GA) + 0.004931(GA)(2) ; R(2) = 0.30), whereas pulsatility index for veins (PIV) in the ductus venosus remained constant (median PIV = 0.82 (0.60-1.12)). In this report, we provide an anatomical atlas of fetal thoracic development using both micro-ultrasound and MRI.We describe anatomical fetal leporine development as can be visualized by micro-ultrasound and MR imaging. The reported reference ranges may be useful for researchers using the fetal rabbit model.
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- 2013
45. Fetal heart pathology on postmortem 3-T magnetic resonance imaging
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Inga, Sandaite, Steven, Dymarkowski, Luc, De Catte, Philippe, Moerman, Marc, Gewillig, Luigi, Fedele, Jan, Deprest, and Filip, Claus
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Heart Defects, Congenital ,Fetal Diseases ,Humans ,Magnetic Resonance Imaging ,Retrospective Studies - Abstract
Postmortem magnetic resonance imaging (pmMRI) is increasingly used in perinatology, typically as an alternative or complement to conventional necropsy for central nervous system anomalies. Overall, it provides reliable information on structural malformations but was shown to be of limited use in examining the fetal heart.We aimed to assess the fetal heart on 3-T pmMRI in a consecutive series of fetuses with structural congenital heart defects (CHD) and to determine diagnostic evaluation limits in case of CHD.A single-center database was retrospectively reviewed. Only fetuses having CHD of functional significance were included. Fetal cardiac anatomy was assessed on T2-weighted 3D multiplanar reconstructed images acquired using isovolumetric voxel size (0.3-0.8 mm(3) ), which allows to visualize cardiac structures in situ in multiple fetal body planes. Cardiac pathology was classified into complex and isolated CHD. On the basis of clinically relevant findings, pmMRI was considered either diagnostic or not diagnostic.A total of 24 fetuses were included in this study. The median gestational age was 22 weeks and 2 days (range 12w5d-34w6d). The median delay between delivery of the fetus and MR was 6 h and 30 min (range 1 h and 30 min-19 h). PmMRI was diagnostic for 12 out of 13 (92.3%) complex CHD and for 6 out of 11 (54.5%) isolated CHD. In case of valvular malformation, a tentative diagnosis was reached in 7/11 cases (64%) on the basis of indirect features.Postmortem MRI is a valid diagnostic tool for CHD in fetuses beyond 16 weeks up to term.
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- 2013
46. Diabetic Muscle Infarction: A Rare Cause of Acute Limb Pain in Dialysis Patients
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Robin Vos, Filip Claus, G. De Vlieger, Bert Bammens, and K. Claes
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Aspirin ,medicine.medical_specialty ,biology ,business.industry ,medicine.medical_treatment ,Infarction ,Case Report ,medicine.disease ,lcsh:Diseases of the genitourinary system. Urology ,lcsh:RC870-923 ,Cystic fibrosis ,Fasciotomy ,Surgery ,Nephrology ,Diabetes mellitus ,medicine ,biology.protein ,Creatine kinase ,business ,Complication ,Kidney disease ,medicine.drug - Abstract
Diabetic muscle infarction is a rare microangiopathic complication occurring in patients with advanced diabetes mellitus. Diabetic patients with chronic kidney disease stage Vd are prone to develop this complication. The presenting symptom is a localized painful swelling of the affected limb. Symptoms usually resolve spontaneously during the following weeks, but frequent relapse can occur and in some cases swelling may lead to compartment syndrome. Biochemical blood analyses show an elevated C-reactive protein, but creatine kinase is often normal. Diagnosis can be made on clinical presentation and imaging, with magnetic resonance imaging as the gold standard. Histology is often not contributive. Treatment consists of rest, analgesics, rigorous glycemic control and low-dose aspirin. Severe cases of compartment syndrome require fasciotomy. In the current paper, we present two diabetic patients with cystic fibrosis, who are treated with automated peritoneal dialysis and suffered from episodic lower limb infarction. We subsequently review 48 episodes of diabetic muscle infarction previously reported in the literature in patients with end-stage renal disease.
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- 2013
47. 18F-MK-9470 PET imaging of the type 1 cannabinoid receptor in prostate carcinoma: a pilot study
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Laura Van den Bergh, Cindy Casteels, Hendrik Van Poppel, Evelyne Lerut, Felix M. Mottaghy, Karolien Goffin, Herlinde Dumez, Kimy M Emonds, Liesbeth De Wever, Michel Koole, Guy Bormans, Karin Haustermans, Steven Joniau, Koen Van Laere, Luc Mortelmans, Christophe Deroose, Filip Claus, MUMC+: DA BV Medische staf (6), RS: NUTRIM - R1 - Metabolic Syndrome, Beeldvorming, and RS: GROW - School for Oncology and Reproduction
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Pathology ,medicine.medical_specialty ,Appendicular skeleton ,PET/CT ,medicine.medical_treatment ,TRACER ,F-18-MK-9470 ,Standardized uptake value ,ACTIVATION ,Prostate cancer ,POSITRON-EMISSION-TOMOGRAPHY ,INTERNATIONAL-SOCIETY ,Prostate ,BIODISTRIBUTION ,medicine ,CB1R ,Radiology, Nuclear Medicine and imaging ,RADIOLIGAND ,Original Research ,PET-CT ,medicine.diagnostic_test ,business.industry ,Prostatectomy ,18F-MK-9470 ,Magnetic resonance imaging ,DOSIMETRY ,medicine.disease ,CANCER ,medicine.anatomical_structure ,Positron emission tomography ,CB1 RECEPTORS ,ISUP CONSENSUS CONFERENCE ,business ,Nuclear medicine ,MRI - Abstract
EJNMMI Research 3(1), 59 (2013). doi:10.1186/2191-219X-3-59, Published by Springer, Berlin
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- 2013
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48. Congenital diaphragmatic hernia
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Dick Tibboel, Eduard Gratacós, Jute Richter, Kypros H. Nicolaides, Philip De Koninck, Jan Deprest, Alexander Engels, Paul Brady, Jaan Toelen, Filip Claus, and Roland Devlieger
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medicine.medical_specialty ,Lung ,business.industry ,Persistent pulmonary hypertension ,Congenital diaphragmatic hernia ,medicine.disease ,Pulmonary hypertension ,Surgery ,medicine.anatomical_structure ,Obstetrics and gynaecology ,Tracheal occlusion ,Anesthesia ,medicine ,Doppler ultrasound ,business ,Fetal therapy - Published
- 2012
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49. Prenatal diagnosis of MPPH syndrome
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Bart, De Keersmaecker, Hilde, Van Esch, Dominique, Van Schoubroeck, Filip, Claus, Philippe, Moerman, and Luc, De Catte
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Adult ,Malformations of Cortical Development ,Polydactyly ,Pregnancy ,Prenatal Diagnosis ,Humans ,Female ,Magnetic Resonance Imaging ,Hydrocephalus ,Ultrasonography - Abstract
We report the prenatal sonographic detection of a fetus with megalencephaly, polymicrogyria, postaxial polydactyly and hydrocephaly. Only 14 patients have been reported in the literature so far, all but one were diagnosed postnatally. The polymicrogyria in the frontoparietal lobe was confirmed by prenatal magnetic resonance imaging. Additionally, a hypoplastic thymus as seen in a 22q11 deletion was present. Although polymicrogyria along with pre-axial polydactyly has been described in 22q11 deletion, the diagnosis of Di George syndrome was ruled out. The etiology of megalencephaly, polymicrogyria, postaxial polydactyly and hydrocephaly has not been revealed yet. A dominant as well as recessive inheritance has been suggested.
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- 2012
50. Comparison of visual grading and free-response ROC analyses for assessment of image-processing algorithms in digital mammography
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Hilde Bosmans, Federica Zanca, Raymond Oyen, Filip Claus, C. Van Ongeval, and J. Jacobs
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Pathology ,medicine.medical_specialty ,Digital mammography ,Computer science ,Siemens ,Breast Neoplasms ,Breast Diseases ,Reference Values ,Digital image processing ,medicine ,Image Processing, Computer-Assisted ,Humans ,Radiology, Nuclear Medicine and imaging ,Grading (tumors) ,Observer Variation ,Receiver operating characteristic ,Video Graphics Array ,Full Paper ,business.industry ,Calcinosis ,Pattern recognition ,General Medicine ,ROC Curve ,Female ,Artificial intelligence ,Microcalcification ,Noise (video) ,medicine.symptom ,business ,Algorithms ,Mammography - Abstract
To compare two methods for assessment of image-processing algorithms in digital mammography: free-response receiver operating characteristic (FROC) for the specific task of microcalcification detection and visual grading analysis (VGA).The FROC study was conducted prior to the VGA study reported here. 200 raw data files of low breast density (Breast Imaging-Reporting and Data System I-II) mammograms (Novation DR, Siemens, Germany)-100 of which abnormal-were processed by four image-processing algorithms: Raffaello (IMS, Bologna, Italy), Sigmoid (Sectra, Linköping, Sweden), and OpView v. 2 and v. 1 (Siemens, Erlangen, Germany). Four radiologists assessed the mammograms for the detection of microcalcifications. 8 months after the FROC study, a subset (200) of the 800 images was reinterpreted by the same radiologists, using the VGA methodology in a side-by-side approach. The VGA grading was based on noise, saturation, contrast, sharpness and confidence with the image in terms of normal structures. Ordinal logistic regression was applied; OpView v. 1 was the reference processing algorithm.In the FROC study all algorithms performed better than OpView v. 1. From the current VGA study and for confidence with the image, Sigmoid and Raffaello were significantly worse (p0.001) than OpView v. 1; OpView v. 2 was significantly better (p=0.01). For the image quality criteria, results were mixed; Raffaello and Sigmoid for example were better than OpView v. 1 for sharpness and contrast (although not always significantly).VGA and FROC discordant results should be attributed to the different clinical task addressed.The method to use for image-processing assessment depends on the clinical task tested.
- Published
- 2012
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