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Biomedical subjects

K Chaumoitre

Publications and source records attributed to K Chaumoitre.

At least 19 recordsLinked to original sources

Diffusion-weighted magnetic resonance imaging with apparent diffusion coefficient (ADC) determination in normal and pathological fetal kidneys.

OBJECTIVES: To assess the use of diffusion-weighted magnetic resonance imaging (DW-MRI) in the evaluation of the fetal kidney and to estimate age-dependent changes in the apparent diffusion coefficient (ADC) of normal and pathological fetal kidneys. METHODS: DW-MRI was performed on a 1.5-T machine at 23-38 gestational weeks in 51 pregnant women in whom the fetal kidneys were normal and in 10 whose fetuses had renal pathology (three with suspected nephropathy, three with renal tract dilatation, one with unilateral renal venous thrombosis, and three with twin-twin transfusion syndrome (TTTS)). The ADC was measured in an approximately 1-cm2 region of interest within the renal parenchyma. RESULTS: ADC values in normal renal parenchyma ranged from 1.1 to 1.8 10(-3) mm2 s-1. There was no significant age-dependent change in the ADC of normal kidneys. In cases of nephropathy, the ADC value was not always pathological but an ADC map could show abnormal findings. In cases of dilatation, the ADC value was difficult to determine when the dilatation was huge. In cases of TTTS, the ADC of the donor twin was higher than that of the recipient twin and the difference seemed to be related to the severity of the syndrome. CONCLUSION: Evaluation of the ADC for fetal kidneys is feasible. Fetal measurement of the ADC value and ADC maps may be useful tools with which to explore the fetal kidney when used in conjunction with current methods. DW-MR images, ADC value and ADC map seem to be useful in cases of suspected nephropathy (hyperechoic kidneys), dilated kidney and vascular pathology (renal venous thrombosis, TTTS).

Diffusion Magnetic Resonance Imaging↗

Advanced combined abdominal and intrauterine pregnancy: a case report.

We present a case of simultaneous abdominal and intrauterine pregnancy following in vitro fertilization and embryo transfer diagnosed during the second trimester. The patient had a recent history of hysteroscopic metroplasty due to in utero exposition to diethylstilboestrol. The pregnancy was managed conservatively with a favorable outcome for the mother and both fetuses.

Adult↗

Fetal magnetic resonance hydrography: evaluation of a single-shot thick-slab RARE (rapid acquisition with relaxation enhancement) sequence in fetal thoracoabdominal pathology.

OBJECTIVES: To evaluate the potential of a single-shot thick-slab RARE (rapid acquisition with relaxation enhancement) sequence in fetal thoracoabdominal magnetic resonance (MR) examinations compared with multislice T2-weighted sequence and postnatal imaging. METHODS: RARE sequence is rapid and provides very heavily T2-weighted images. Twenty-seven fetal thoracoabdominal MR imaging examinations were performed at 23-38 weeks using our conventional protocol. This included thin multislice T2-weighted half-Fourier acquired single-shot turbo spin-echo (HASTE) sequence and thin-slice GE (gradient echo) T1-weighted images with a 1.5-T MR unit. A single-shot thick-slab (60 mm) RARE sequence was added to all MR examinations. The acquisitions were obtained with the mother breath-holding. The thick-slab heavily T2-weighted images were compared with HASTE sequence images and with postnatal imaging in all cases. RESULTS: The thick-slab RARE sequence did not show additional abnormalities compared with the conventional protocol but displayed an overall view of the urinary tract, tracheobronchial tract and small bowel. It gave information that was highly correlated with postnatal imaging, such as abdominal plain films, chest film or cystography. The quality of the thick-slab RARE images was considered as good in 13 cases (48%), moderate in 12 cases (45%) and poor in two cases (7%). CONCLUSION: Although thick-slab RARE sequence does not show additional abnormalities compared with the conventional protocol, it illustrates very nicely static fluids such as those in urinary dilatation, the esophagus and small bowel (normal or dilated) and thoracic cystic masses. It is very rapid (5 s) to perform, allows fetal hydrography, and correlates well with postnatal imaging.

Adult↗

Differential diagnosis of fetal hyperechogenic cystic kidneys unrelated to renal tract anomalies: A multicenter study.

OBJECTIVES: To identify important factors in the differential diagnosis of renal cysts associated with hyperechogenic kidneys. METHODS: This was a retrospective multicenter study. We identified 93 fetuses presenting between 1990 and 2002 with hyperechogenic kidneys and which had a diagnosis of nephropathy confirmed later. We analyzed retrospectively the prenatal ultrasound findings of those fetuses which were found sonographically to have renal cysts. RESULTS: Of the 93 fetuses presenting with hyperechogenic kidneys and with a later diagnosis of nephropathy, there were 28 with autosomal dominant polycystic kidney disease (ADPKD), 31 with autosomal recessive polycystic kidney disease (ARPKD), 11 with Bardet-Biedl syndrome, nine with Meckel-Gruber syndrome, six with Ivemark II syndrome, one with Jarcho-Levin syndrome, one with Beemer syndrome and one with Meckel-like syndrome. One third of the fetuses (30/93) had renal cysts. Cystic characteristics (size, location, number) were not very useful for diagnosis; more useful was diagnosis of an associated malformation. Three (11%) of the fetuses with ADPKD had cysts, as did nine (29%) of those with ARPKD, three (27%) of those with Bardet-Biedl syndrome, all (100%) of those with Meckel-Gruber syndrome, three (50%) of those with Ivemark II syndrome, and each of the three cases with other syndromes (Jarcho-Levin, Beemer and Meckel-like syndromes). None of the cases with trisomy 13 had cysts. There were no associated malformations in the 12 cases with renal cysts and polycystic kidney disease; the other 18 cases with renal cysts were associated with malformations that were often specific, such as polydactyly in Bardet-Biedl and Beemer syndromes, occipital defect and Dandy-Walker malformation in Meckel-Gruber or Meckel-Gruber-like syndromes, and thoracic and/or vertebral abnormalities in Jarcho-Levin and Beemer syndromes. CONCLUSION: Renal cysts associated with hyperechogenic kidneys are not rare. The clue to diagnosis is the demonstration of an associated malformation. If no malformation is found, the main diagnosis remains polycystic kidney disease, i.e. ARPKD or ADPKD.

Bardet-Biedl Syndrome↗

Prenatal prognosis of congenital diaphragmatic hernia using magnetic resonance imaging measurement of fetal lung volume.

OBJECTIVES: To investigate the correlation between fetal lung volume (FLV), measured with magnetic resonance imaging (MRI), and postnatal mortality in newborns with prenatally diagnosed isolated congenital diaphragmatic hernia (CDH). METHODS: In a 4-year prospective multicenter study, 77 fetuses with isolated CDH diagnosed between 20 and 33 weeks' gestation underwent fast spin-echo T2-weighted lung MRI. These MRI-FLV measurements were compared with a previously published normative curve obtained in 215 fetuses without thoracoabdominal malformations and with normal ultrasound biometric findings. FLV measurements were correlated with postnatal survival. The mean gestational age at MRI was 31.3 weeks. RESULTS: The measured/expected FLV ratio was significantly lower in the newborns with CDH who died compared with those who survived (23.6 +/- 12.2 vs. 36.1 +/- 13.0, P < 0.001). When the ratio was below 25%, there was a significant decrease in postnatal survival (19% vs. 40.3%, P = 0.008). Survival was significantly lower for neonates when one lung could not be seen by fetal MRI compared with those fetuses with two visible lungs on MRI (17.9% vs. 62.1%, P < 0.001). CONCLUSION: In isolated CDH, FLV measurement by MRI is a good predictor of postnatal mortality due to pulmonary hypoplasia.

Female↗

[Non-traumatic abdominal emergencies in paediatric practice].

Do advances in MR imaging and Computed Tomography have encroached upon the private territory of Ultrasound-Doppler imaging on paediatric practice? Do the enthusiasm promoted by the use of CT on non traumatic acute abdomen in adult has contaminated the indomitable village of paediatric radiologist? Undoubtfully, Ultrasound-Doppler stayed the first imaging modality to perform. However, the habits are less crystallised than a few years ago. The goal of this article is to describe the ultrasound findings and the potential indications for MRI or CT in the major non traumatic abdominal paediatric emergencies.

Abdomen, Acute↗

[Imaging of the pediatric pancreas: state of the art].

The use of high frequency (7-12 MHz) transducers on state of the art US units equipped with Doppler imaging provides excellent evaluation of the pediatric pancreas that compares to other cross-sectional imaging techniques. The availability of multidetector CT imaging reduces the need for sedation but requires additional review of the indications and protocols to avoid unnecessary radiation exposure. Evaluation of pancreatitis and tumors remains the main indication. Advances in MR imaging and MRCP has lead to very good results in children. Storage diseases of the pancreas can be diagnosed at MRI. The length of the examinations, the need for sedation and the limited spatial resolution remain the main pitfalls of MR imaging of the pancreas in pediatric patients.

Child↗

Fetal brain injury.

Improvements in MRI techniques widen the indications for fetal brain imaging and fetal brain injury represents the third indication of fetal brain magnetic resonance imaging (MRI) after the evaluation of suspected central nervous system (CNS) malformations and ventricular dilatation. Optimal MR imaging technique is necessary in order to collect as much data as possible about the fetal brain. Diffusion images can be used routinely in addition to the standard protocol of fetal brain MRI that consists of T1 and T2 weighted images of the fetal brain. Monovoxel proton magnetic resonance spectroscopy can also be performed in utero, but this technique is still more part of research protocol than of routine clinical protocol. Fetal brain injury includes hypoxia-ischemia, congenital infections (especially toxoplasmosis and cytomegalovirus infections), brain damage due to malformation such as vascular brain malformation and heart malformation, pregnancies at risk of fetal brain damage, and even inherited metabolic diseases, especially mitochondrial diseases. MRI findings in fetal brain injury consist of acute or chronic lesions that can be seen alone or in combination. Acute response of the fetal brain is less commonly seen than the chronic response compared to the brain response encountered in the postnatal period.

Brain Injuries↗

Voiding cystourethrography in boys. Does the presence of the catheter during voiding alter the evaluation of the urethra?

PURPOSE: We determined whether the presence of the catheter during the voiding phase of voiding cystourethrography alters the evaluation of the urethra concerning the normal structures as well as pathological findings, especially posterior urethral valves. MATERIALS AND METHODS: A total of 123 males 3 days to 16 years old (median age 2.6 months) underwent voiding cystourethrography. Urethral catheterization was performed in all cases. Four views were taken during the voiding phase with and without the catheter in place. Only 80 patients had available results. These examinations were studied with special attention to the normal structures and pathological findings. RESULTS: A total of 36 examinations (45%) were normal. Pathological findings were observed in 44 patients (55%), with abnormal vesical findings and/or vesicoureteral reflux in 33 (41.25%). In 11 patients (13.75%) 12 urethral abnormalities were found (posterior urethral valves 3, hypospadias 4, prostatic utricle 1, verumontanum polyp 1, prune belly syndrome with urethral dilatation 1, imperforate anus with urethral fistula 1 and urethral duplication 1). In all cases excluding those involving hypospadias there was no difference between the views with and without the catheter. However, concerning the normal structures, the verumontanum and fossa navicularis were better delineated without the catheter in 27% and 33% of cases, respectively. CONCLUSIONS: Our study shows that a urethral catheter does not alter the diagnosis of abnormalities of the posterior urethra but may hamper the observation of normal structures or abnormalities of the anterior urethra.

Adolescent↗

[Tumorlike form of bladder schistosomiasis in children].

Two tumorlike forms of urinary schistosomiasis are reported. Diagnosis was suspected as the patients exerted haematuria while they originated from a geographic area where schistosomiasis is endemic. Terminal urine samples were positive for Schistosoma haematobium. Cystoscopy revealed an hemorrhagic granulomatous polyp in one case and villous polyps in the other case, associated with suggestive lesions of schistosomiasis. Schistosoma haematobium infection in children is uncommon in Europe and rarely considered in the diagnosis of haematuria.

Animals↗

[Imaging of neonatal neurological disorders].

Neonatal brain disorders consist of a wide chapter including brain malformations, hypoxic-ischemic encephalopathy, intracranial infections, perinatal trauma and metabolic encephalopathies. The aim of this review paper is to describe the main imaging modalities (ultrasonography, CT, MRI) that are used extensively for the diagnosis of neonatal brain disorders, with their respective advantages and limitations, to illustrate and describe the main brain lesions encountered in the neonatal period, particularly with MRI since its role has increased over the recent years. We will focus on hypoxic-ischemic encephalopathy, materno-fetal infections, metabolic encephalopathies and stroke, those four conditions being the most frequent so far. Imaging modalities, especially MRI, by showing the extent of brain damage, are part of the prognostic factors in cases of infective causes and of hypoxic-ischemic origin. MRI is also very efficient in showing brain damage as atrophy and white matter abnormalities suggestive of an underlying abnormal brain of metabolic origin.

Age Factors↗

[MRI and in utero ventriculomegaly].

Ventriculomegaly constitutes the major indication of fetal brain MRI. MRI is therefore of utmost importance to look for a cause through the depiction of criteria of malformations and through the definition of criteria of destructive lesions. Malformations and destructive lesions are the most common causes of ventricular dilatation. Some challenging points are worth mentioning in term of mechanism with the challenge of hydrocephalus (in term of increased in intracranial pressure) and of isolated ventriculomegaly. The image itself is also challenging since a similar image may be of different origin. In term of natural history of fetal brain injury an irregular, nodular aspect of the ventricular wall and/or the germinal matrix is often the only pathologic MRI finding that is known to be of clastic origin. In term of prognosis the challenge is represented by the isolated mild ventriculomegaly, the literature being quite confusing. The purpose of this review paper is to highlight the underlying mechanisms and pathophysiology of ventricular dilatation based on results from the literature as well as from personal experience.

Cerebral Ventricles↗

[Bilateral vas deferens agenesis and inguinal hernia in a child. A rare, early presentation of cystic fibrosis].

UNLABELLED: Epididymal and ductal anomalies can be discovered incidentally during inguinal herniorraphy in children. The congenital bilateral absence of vas deferens is frequently associated with cystic fibrosis. CASE REPORT: This agenesia of vas deferens was detected in a 5-month-old boy who underwent an inguinal herniorraphy. Although the child did not present any symptoms, he actually presented cystic fibrosis: the sudoral test showed high levels of chloride (95 mmol/L) and an isolated homozygous delta F 508 deletion on the gene CFTR was evidenced on genetic investigations. CONCLUSION: The congenital bilateral absence of vas deferens is the most frequent anomaly of the male genital tract discovered in adults investigated for azoospermia. Relations with cystic fibrosis are well established but congenital bilateral absence of vas deferens discovered during infancy is an exceptional situation that requires genetic investigations to show evidence of a likely underlying cystic fibrosis.

Cystic Fibrosis↗

Rate of abnormal osteoarticular radiographic findings in pediatric patients.

OBJECTIVE: The objective of our study was to assess the rate of abnormal radiographic findings in the most frequent osteoarticular locations of traumatic injury in a pediatric population. SUBJECTS AND METHODS: During two periods of 12 weeks each, all patients admitted to the pediatric emergency department for osteoarticular trauma who underwent radiography were prospectively included in this study. A connection was drawn between the rate of abnormal radiographic findings for the seven most frequently radiographed locations and the clinical findings. RESULTS: Of 3128 locations of trauma in 2470 children, only 22% of the radiographic examinations were considered to reveal abnormal findings. In decreasing order, the hand and fingers, the ankle, the wrist, the knee, the elbow, the foot and toes, and the forearm were the most frequently examined locations. The rate of abnormal findings was 25.7% for the hand and fingers, 9.0% for the ankle, 42.5% for the wrist, 9.5% for the knee, 33.3% for the elbow, 18.3% for the foot, and 43.2% for the forearm. When only the direct sign of fracture was taken into account, these rates decreased for the ankle and knee to 2.6% and 1.9%, respectively. There was always a significant link between the degree of clinical suspicion and the rate of abnormal radiographic findings. However, fewer than 50% of the cases with high clinical suspicion of fracture were radiographically confirmed. CONCLUSION: It appears necessary, especially in cases of lower limb trauma, to evaluate clinical tests, including the implementation of the Ottawa ankle rules, to reduce the number of unnecessary radiographic examinations. This reduction will improve some parameters of children's quality of life and will significantly decrease the cost of emergency care.

Adolescent↗