Doppler ultrasound in the diagnosis of Budd-Chiari syndrome in children after split liver transplantation.

PURPOSE: To assess the capabilities of a velocity ratio>3 for the diagnosis of Budd-Chiari syndrome (BCS) in children after split liver transplantation using Doppler ultrasonography (DUS). MATERIALS AND METHODS: A total of 28 children who underwent liver transplantation using a split procedure were included. There were 11boys and 17girls with a mean age of 3.8years (range: 0.7-12years). Velocity ratio between blood velocity upstream of the anastomosis and that at the level of the inferior vena cava anastomosis was calculated. Sensitivity, specificity and accuracy of DUS for the diagnosis of BCS were estimated using a velocity ratio>3. RESULTS: Eight children (8/28; 29%) had BCS and 20 (20/28; 71%) did not have BCS using the standard of reference. A velocity ratio>3 on DUS yielded 88% sensitivity (95% CI: 53-98%), 80% specificity (95% CI: 58-92%) and 82% accuracy (95% CI: 64-92%) for the diagnosis of BCS. CONCLUSION: A velocity ratio>3 on DUS is a reliable finding for the diagnosis of BCS in children after split liver transplantation.

Cardiac CT or MRI in pediatric practice: Which one to choose?

The different factors involved in the choice of the best cardiovascular imaging examination for pediatric patients are justification, radiation protection, sedation, resolutions (spatial and contrast), morphology or function, intervention and contrast enhancement. Computed tomography is preferable for all coronary artery conditions, any arterial or venous abnormalities in newborns and infants and in the preoperative assessment for tetralogy of Fallot. Magnetic resonance imaging is used for any tumoral or functional assessment, cardiomyopathy or arrhythmia or if the child's participation and/or size of the structures being examined allows using this technique.

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.

Value of diffusion-weighted images in differentiating mid-course responders to chemotherapy for osteosarcoma compared to the histological response: preliminary results.

BACKGROUND: Preoperative diffusion-weighted MRI (DW-MRI) has been described as an efficient method to differentiate good and poor responders to chemotherapy in osteosarcoma patients. A DW-MRI performed earlier during treatment could be helpful in monitoring chemotherapy. OBJECTIVE: To assess the accuracy of DW-MRI in evaluating response to chemotherapy in the treatment of osteosarcoma, more specifically at mid-course of treatment. MATERIALS AND METHODS: This study was carried out on a prospective series of adolescents treated for long-bone osteosarcoma. MR examinations were performed at diagnosis (MRI-1), at mid-course of chemotherapy (MRI-2), and immediately before surgery (MRI-3). A DW sequence was performed using diffusion gradients of b0 and b900. The apparent diffusion coefficients (ADC1, ADC2, ADC3, respectively), their differentials (ADC2 - ADC1 and ADC3 - ADC1), and their variation (ADC2 - ADC1/ADC1 and ADC3 - ADC1/ADC1) were calculated for each of these three time points. RESULTS: Fifteen patients were included. Patients with no increase in ADC showed a poor response to chemotherapy on their histology results. At mid-course, the three calculated values were significantly different between good and poor responders. ADC2 - ADC1 enabled us to detect, with 100% specificity, four out of seven of the poor responders. There was no significant difference in the values at MRI-3 between the two groups. CONCLUSION: DW-MRI performed both at baseline and mid-course of neoadjuvant chemotherapy is an efficient method to predict further histological response of osteosarcoma. This method could be used as an early prognostic factor to monitor preoperative chemotherapy.

[Pediatric thoracic spine radiographs: Comparison of two scintillators]. / Radiographies thoraciques pédiatriques: comparaison de deux détecteurs à mémoire.

PURPOSE: To compare image quality and radiation exposure from pediatric thoracic spine radiographs from two systems, one using a granular structure scintillator and another using a needle structure scintillator with 40% reduction of exposure. PATIENTS AND METHODS: Randomized prospective study of 296 patients divided into 2 groups of 5 weight categories from 4 to 60 kg. Standard technique parameters are used for granular structure scintillators with dose reduction of 40% applied for needle structure scintillators based on results from a phantom study. Image quality based on detectability of 8 anatomical structures for both types of scintillators was assessed by 6 blinded radiologists. Exposure was expressed by DLP. Results underwent statistical analysis. RESULTS: Overall, image quality was superior with corresponding dose reduction between 33-46% according to weight with needle structure scintillators. For the 4 lower weight categories, image quality was identical. CONCLUSION: With image quality at least equal, new needle structure scintillator units allow a dose reduction of about 40%.

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.

[Radiography of scoliosis: comparative dosimetry between conventional technique and digital fluorography]. / Radiographie des scolioses: dosimétrie comparée entre la technique conventionnelle et la fluorographie numérique.

OBJECTIVE: Compare the irradiation delivered in conventional radiography and digital radiography by image intensifier during a scoliosis workup. PATIENTS AND METHODS: Our prospective randomized study included 105 patients, all of whom were identified according to sociodemographic parameters as well as criteria evaluating the quality of the full front spinal x-ray at PA incidence. The entry dose at the scapula and the exit dose in interorbital, thyroid, mammary, and hypogastric projection was measured by thermoluminescent dosimeters. RESULTS: The results of 71 girls and 28 boys, aged a mean 13.8 years with a mean weight of 47 kg were analyzed. At equal image quality, the entry dose was not significantly different between the two techniques; the mean exit dose reduction was 64% during digital acquisition. This reduction involved the interorbital (162%), mammary (43%), and thyroid (309%) regions. However, this system is more irradiating in the hypogastric region (34%). CONCLUSION: The dosimetric evaluation of the different imaging techniques used to explore the entirety of the spine should be part of radiologists' quality standard used to document their work and their choices.

[Percutaneous treatment of cystic lymphangiomas]. / Malformations lymphatiques: traitement percutané.

Management of cystic lymphangioma necessitate for optimal diagnosis and treatment the expertise of a trained multidisciplinary team including dermatologists, radiologists, plastic and vascular surgeons. An initial imaging work-up of these lesions by ultrasound Doppler examination and MR imaging are necessary before treatment planning. Depending of the size, the location, the risk for the adjacent organs, a therapeutic decision may be mandatory. Percutaneous sclerotherapy is a safe and efficient treatment. It is the treatment of choice that must be proposed in first intention.