[Post-mortem perinatal imaging: State of the art and perspectives, with an emphasis on ultrasound]. / Imagerie post-mortem périnatale : état des lieux, point de vue et perspectives, échographiques en particulier.

The fields of application of post-mortem imaging have been exponentially growing for 10 years. Its potential to identify the cause of death in trauma and ballistic cases is now properly documented. In pediatric and perinatal practice, large significant series are less available, except for MRI and central nervous system analysis where scientific evidence is now robust. After a short historical and state-of-the-art review, we will try to depict the way we see the future of this sub-specialty of post-mortem imaging, especially in specific perinatal situations.

Fetal skeletal computed tomography: when? How? Why?

PURPOSE: To study the additional role of fetal skeletal computed tomography in suspected prenatal bone abnormalities. MATERIALS AND METHODS: Two centers included in a retrospective study all fetuses who benefited from skeletal computed tomography for a suspected constitutional bone disease or focal dysostosis. RESULTS: A total of 198 patients were included. CT was performed in 112 patients (56%) for an isolated short femur below the third percentile (group A), in 15 patients (8%) for bowed or fractured femur (group B), in 23 patients (12%) for biometric discrepancy between a short femur and increased head circumference (group C) and in 48 patients (24%) for suspected focal dysostosis (group D). CT was interpreted as normal in 126 cases (64%), i.e. 87% in group A, 0% in group B, 65% in group C and 25% in group D. When including only cases with postnatal or postmortem clinical and/or radiological confirmation was available, CT provided additional and/or more accurate information than ultrasound in 20% of cases in group A, 66% in group B, 30% in group C and 72% in group D. Sixty-seven percent of patients in whom CT was interpreted as normal were lost to follow-up. CONCLUSION: In isolated short femur, fetal skeletal CT is normal in the great majority of cases although protocolized follow-up of these babies is absolutely compulsory, as a large proportion is lost to follow-up. Fetal skeletal CT can confirm or improve imaging for the suspected diagnosis in suspected focal dysostosis or constitutional bone disease.

Contribution of the foetal uro-MRI in the prenatal diagnosis of uronephropathies.

PURPOSE: To study the complementary diagnostic value and role in the perinatal management of foetal MRI in the prenatal diagnosis of abnormalities of the urinary tract. PATIENTS AND METHODS: Retrospective monocentric study from November 2002 to June 2011 of foetuses benefiting from an MRI after ultrasound diagnosis of uronephropathy abnormalities. Ultrasound and MRI data were compared with postnatal radiological and/or surgical data or with the foetopathology. The MRI analysis focused on the diagnostic concordance with the ultrasound, the complementary diagnostic contribution and/or a change in perinatal care. RESULTS: Of the 154 MRI examined, a follow-up was obtained for 108 cases. The indications for MRI were classified into six groups: suspected renal agenesis (n = 20, 18.5%), posterior urethral valve (n = 20, 18.5%), reflux or megaureter (n = 14, 13%), uretropelvic junction syndrome (n = 24, 22.5%), enlarged kidneys (n = 7, 6.5%) and others (n = 23, 21%). The information supplied by ultrasound was confirmed by MRI in 72 patients (67%). MRI provided additional data for 36 patients (33%) and changed the perinatal care for 16 patients (15%). CONCLUSION: Foetal uro-MRI is a useful complementary tool in the prenatal diagnosis of some uropathy abnormalities.

[Urinary dribbling in girls: which investigations in 2012?]. / Écoulement urinaire chez la fille: quelle imagerie en 2012?

Continuous urinary leakage, despite normal deliberate voiding, must suggest the diagnosis of ectopic ureter, more specifically in girls. Ectopic ureter is usually associated with duplex kidney and complete ureteral duplication. The strategy of investigations has changed over the past few years, due to MRI development in the analysis of urinary tract malformations. We report the case of a 4-year-old girl who presented with these symptoms and had a suspicion of left duplex kidney on the prenatal ultrasonography (US). Two US examinations during the first months of life were compatible with a left duplex kidney without any complication. Another US at the age of 4 years was reported as normal. We completed the investigation with MR urography, which revealed a left duplex kidney with a poorly functioning dysplastic upper pole, and the orifice of the ureter of this upper pole inserting in the vagina. The surgical treatment, realized by celioscopy, was partial nephrectomy of the upper pole, removing most of the ectopic ureter. US is the first exam to investigate urinary tract malformations. However, duplex kidney with small dysplastic pole and ectopic insertion of a nondilated ureter may be difficult to see, and a normal US should never end the investigations. Intravenous urography and renal scintigraphy used to be the reference complementary exams, but are now replaced by MR urography. Without using ionizing radiation, MR urography can visualize duplex kidney and ectopic ureteral insertion with high resolution, and evaluates renal function of each kidney and each pole. These morphological and functional data are essential to determine the surgical treatment.

[Lung signal on fetal MRI: normal values and usefulness for congenital diaphragmatic hernia]. / Signal pulmonaire foetal en IRM: valeurs normales et application à la hernie diaphragmatique congénitale.

PURPOSE: To demonstrate the feasibility of lung signal measurements on fetal MRI, present normal signal intensity curves, and assess its value to predict pulmonary hypoplasia. PATIENTS AND METHODS: Prospective multicentric study of 115 fetuses without lung disease and 33 fetuses with left diaphragmatic hernia and high risk of pulmonary hypoplasia. Signal measurements were obtained of the lungs, liver and psoas from fast heavily T2W sequences (HASTE, 2 measurements and 2 orthogonal planes for each organ, oval-shaped ROI of 1 cm2 for lungs and liver, and 0.5 cm2 for the psoas). RESULTS: No direct linear relationship existed between lung signal intensity and gestational age. A direct linear relationship existed between liver signal and gestational age, and between psoas signal and gestational age. An exponential relationship existed for the ratios left lung/liver, right lung/liver, left lung/psoas and right lung/psoas. The inter-observer agreement was excellent, ranging between 0.888 and 0.926. Significant differences were observed between normal fetuses and fetuses with diaphragmatic hernia for the right lung/liver and left lung/psoas ratios. CONCLUSION: Normal fetal lung signal intensity curves can be obtained. Lungs at risk of hypoplasia presented significant alterations of signal ratios. The prognostic value of such results requires additional postnatal clinical follow-up.

Percutaneous treatment of osteoid osteoma by laser thermocoagulation under computed tomography guidance in pediatric patients.

To evaluate the efficiency of laser thermocoagulation under computed tomography (CT) guidance in the treatment of osteoid osteoma within a strictly pediatric group. Twenty-five patients aged 4 to 17 years were treated under CT by laser thermocoagulation. The nidus measured on average 10.1 mm. Pain relief was the main item for evaluation of the effectiveness of our treatment. Follow-up ranged from 3 months to 61 months (mean, 26 months). Technical success was achieved in 100%. Thermocoagulation proved to be initially effective in 24 of 25 children (96%) and had a positive long-term effect in 23 of 25 children (92%). We had four minor complications and one severe complication (partial osteonecrosis of the talus). Laser thermocoagualation is an effective treatment for osteoid osteoma in pediatric patients.

[Kidney trauma in children: state of the art medical imaging]. / Traumatisme du rein de l'enfant: bonnes pratiques en imagerie médicale.

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.

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.

[Imaging of the pediatric pancreas: state of the art]. / Imagerie du pancréas de l'enfant en 2005.

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.

[Immature hemangiomas in infants: MR and Doppler-US imaging features]. / Sémiologie IRM et écho-Doppler des hémangiomes immatures du nourrisson: à propos de 12 cas.

PURPOSE: To determine the MR imaging features of immature hemangiomas. To discuss the value of MR imaging compared to Doppler ultrasonography (US). MATERIALS AND METHODS: We performed a retrospective study of clinical, Doppler US and MRI data of 12 immature hemangiomas in 11 children. The mean age was 2 months and 21 days. The mean clinical follow up was 22 months and 7 days. RESULTS: MRI was performed for non-diagnosed lesions (4 cases) or to further define lesion extension (8 cases). The lesions either involved the head and neck (8 cases) or the extremities (4 cases). At MR imaging, all immature hemangiomas corresponded to well defined homogeneous T2W hyperintense masses. On T1-weighted images, 11 immature hemangiomas were isointense with intense homogeneous enhancement. Eleven tumors contained linear low signal intensity flow voids. Ten lesions had superficial cutaneous and/or subcutaneous extension whereas 2 lesions had intra-muscular extension. At Doppler US, immature hemangiomas were highly vascularized masses, with well defined margins, often compressibles, homogeneous isoechoic or heterogeneous with nodular hypoechoic foci, relative to subcutaneous fat. A diagnosis of immature hemangioma was confirmed either by pathology (2 cases) or clinical follow up (10 cases). CONCLUSION: In our study, the MR imaging features of immature hemangiomas were reproducible and similar to reports from the literature. MRI is a useful tool to better define the extent of immature hemangiomas, which can be difficult to assess at US. The sensitivity and specificity of MR imaging for this pathology remain to be defined.

[Non-traumatic abdominal emergencies in paediatric practice]. / Les urgences abdominales non traumatiques de l'enfant.

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.

Unusual association of congenital middle ear cholesteatoma and first branchial cleft anomaly: management and embryological concepts.

OBJECTIVE: To report two cases of an undescribed association of first branchial cleft fistula and middle ear congenital cholesteatoma and to discuss management and embryological hypothesis. DESIGN: Retrospective study and review of the literature RESULTS: Both patients were young girls free of past medical or surgical history. Surgical removal of the first cleft anomaly found in the two cases a fistula routing underneath the facial nerve. Both cholesteatomas were located in the hypotympanum, mesotympanum. In one case, an anatomical link between the two malformations was clearly identified with CT scan. DISCUSSION: The main embryological theories and classification are reviewed. A connection between Aimi's and Michaels' theories (congenital cholesteatoma) and Work classification might explain the reported clinical association.

Value of fetal skeletal radiographs in the diagnosis of fetal death.

The aim of this study was to assess the value of fetal skeletal radiographs in determining the etiology of fetal death. A total of 1193 post-mortem fetal skeletal radiographs were analysed. Fetuses were classified into one of three groups (group I: abnormality diagnosed during pregnancy; group II: maternal pathology; group III: spontaneous abortion of pregnancy, IIIa before 26 weeks of gestation (WG), IIIb after 26 weeks of gestation). Face, supine and lateral skeletal views were performed. Skeletal abnormalities were detected in 33.9% of the fetuses, including 22.7% with minor abnormalities (abnormal rib number, no nasal bone ossification, amesophalangia or P2 hypoplasia of the fifth digit) and 14.5% with major abnormalities (other skeletal abnormalities). Among the fetuses with major abnormalities, 98.8% came from group I, 2.9% came from group II, 2.3% came from group IIIa and none came from group IIIb. Fetal skeletal radiographs are not useful in fetuses arising from spontaneous abortion of pregnancy without abnormality on ultrasound screening, abnormality clinical examination or in fetuses with prenatal diagnosis of chromosomal abnormality. This practice is valuable only if there is a multidisciplinary team, with all the participants (pathologists, radiologists, geneticists) knowledgeable about fetal pathology. In the absence of this multidisciplinary approach, it is easier to X-ray all fetuses to avoid misdiagnosis and the important consequences for genetic counselling.

Postmortem assessment of fetal diaphyseal femoral length: validation of a radiographic methodology.

Depending on the general condition of fetal remains, forensic specialists might face difficulties concerning age estimation. Reference tables and regression equations are helpful devices in this task, although they are generally applied for complete fetuses or fetal remains including soft tissues. However, the problem of age estimation stays for osseous remains, both for entire bones and ossified parts, since most of the reference tables come from ultrasonographic measurements, which are not easily reproducible on fetal osseous remains. Furthermore, the ultrasonographic measurements contain slight errors in comparison to the real anatomical ones. This study describes a radiographic protocol and a measurement technique that facilitate and improve bone measurements, and therefore, facilitate age estimation, too. A qualitative criterion, namely a clear-cut bony endplate, was defined and tested. Its reliability (repeatability and reproducibility) turned out to be good, showing nonsignificative differences to the threshold of 0.05, with average errors of 0.26 and 0.44 mm respectively. Moreover, concerning the test of eventual size differences between the right and left femurs showed a P value < 0.0001. The test of the qualitative criterion was based on the comparison of the radiographic in situ femur measurements and the radiographic measurements of the same bones after dissection. The results were satisfactory, since an average error of 0.58 mm was obtained, which did not give any significant differences to the threshold of 0.05. It was concluded that this methodology provides an easy and precise new measurement tool for forensic practice, and can allow us to establish some nonultrasonographic tables, which fit our population.

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.

[Is ultrasonographic evaluation the the length of the kidney possible in children? Apropos of a prospective study in Madagascar children less than 1 year of age]. / L'évaluation echographique de la taille des reins chez des enfants est-elle possible? A propos d'une étude prospective chez des enfants malgaches de moins de un an.

Renal US was prospectively performed in 124 madagascan children less than 1 year of age. Patients were examined in the prone position and maximum kidney length was measured in the longitudinal plane. These measurements and the height and weight of our patient population were compared to published tables. Kidney length and height and weight of our patient population were inferior to the previously published reference data and the growth curve of kidneys steeper than normative standards (p < 0.001). Because of the important variability in US measurement of kidney length it is not possible to definitely conclude that length and growth curve of kidneys in madagascan children are statistically different from those of the published normative standards.