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Biomedical subjects

M Panuel

Publications and source records attributed to M Panuel.

At least 19 recordsLinked to original sources
PubMed2007

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↗
PubMed2006

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↗
PubMed2006

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↗
PubMed2006

[Kidney trauma in children: state of the art medical imaging].

Traumatic renal lesions have some particularities in the pediatric age group, especially for anatomic reasons. Imaging is very important for diagnosis and staging. Ultrasonography with Doppler is the first line examination performed in children and frequently allows initial diagnosis. From the Doppler-ultrasonographic results and the type of trauma, renal Computed Tomography (CT) is complementary performed. The association of these imaging techniques allows comprehensive work-up of traumatic renal lesions, and also of associated or pre-existing lesions. Conservative management is the rule in most cases. Interventional imaging techniques are sometimes used for therapeutic care of renal pedicular vascular lesions or lesions of the collecting system. Far from the traumatic event, imaging allows to follow up the morphologic and functional evolution of major renal lesions, in particular lesions of excretory renal ducts.

Algorithms↗
PubMed2006

[Reliability of the Sauvegrain and Nahum method to assess bone age in a contemporary population].

PURPOSE: The Sauvegrain and Nahum method can be used to assess bone age in addition to methods based on hand and wrist radiographs in children between 9 and 15 years of age. The aim of this study was to evaluate the reliability of this method in a contemporary population. MATERIAL AND METHODS: Elbow radiographs taken for acute trauma in 106 patients (42 girls, 64 boys) aged from 9 to 15 years old were analyzed by four radiologists. Inclusion in the study required the absence of chronic disease and previous trauma as well as parental consent. RESULTS: There was no significant difference between the four observers. The differences between bone age (BA) and chronological age (CA) were 5+/-1 months for the study group, 3.5+/-9 months for the female group, and 6+/-12 months for the male group. Bone age was overestimated compared with chronological age. There was a good correlation between CA and BA (r = 0.84). CONCLUSION: The Sauvegrain and Nahum method seems to overestimate CA in a contemporary population.

Adolescent↗
PubMed2005

[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↗
PubMed2005

[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↗
PubMed2004

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↗
PubMed2004

[Prenatal MRI diagnosis of esophageal atresia].

The diagnosis of esophageal atresia may be suspected on prenatal ultrasonography in fetuses with absent or small stomach, upper esophageal dilatation and unexplained polyhydramnios. However, the diagnostic value of these findings is relatively poor. Two cases are reported where MRI appeared to be accurate for establishing the diagnosis of this congenital anomaly.

Adult↗
PubMed2004

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↗
PubMed2003

[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↗
PubMed2003

[Anatomic study of the anterior patellar groove in the fetal period].

PURPOSE OF THE STUDY: We performed a biometric analysis of the femoral trochlea in the fetus and compared our findings with those observed in adults in order to search for correlations with other biometric parameters of the femur. MATERIAL AND METHOD: Twenty-two fetuses (44 knees) conserved in formol and free of known orthopedic disease were studied. Fetal age ranged from 26 to 40 weeks. After anatomic dissection, digitalized images were used to obtain angle measurements with a dedicated software. Measurements made on the distal epiphyseal view were: anteroposterior dimension of the condyles, medial and lateral protrusion of the trochlear borders, difference in condyle height, length of the trochleal borders, alpha angle of the trochlear groove, trochlear slope. Measurements made on the AP femoral view were: femoral anteversion, length of the femoral neck, neck-shaft angle. Spearman's test was used to search for correlations. Results were compared with measurements obtained under the same conditions in a series of 32 adult knees published by Wanner. RESULTS: The trochlear alpha angle was 148 degrees (coefficient of variation 4%). The angle was greater than 150 degrees for 18 trochleae. The lateral border of the trochela was higher than the medial border in 37 of the 44 knees. There was no correlation with age and gender. Femoral anteversion was 27.01 degrees, with a high coefficient of variation (46%), and no correlation with the trochlear alpha angle. Comparison with measurements made on the adult knees revealed no significant difference. DISCUSSION: This is the first report of statistically significant biometric data of the fetal trochlea. The morphology of the lower femur observed during the third trimester of fetal live is the same as observed in adults. Morphological changes in the proximal femur occurring during growth do not appear to modify the morphology of the distal femur. The asymmetrical ingression of the patella into the trochlea, characteristic of modern man, is considered to result from bipedalism. Our study would suggest that the anatomic characteristics of the trochlea could have been integrated into the genoma during the course of evolution. This would be in favor of a genetic origin of trochlear dysplasia.

Adult↗