No abstract available

[en] Because of their longer life expectancy, the risk of late manifestations of detrimental radiation effects is greater in children than in adults. Many paediatric radiographic examinations are performed by surgeons, paediatricians and adult radiologists with variable knowledge of specific paediatric pathology, radiographic technique and radioprotection. Therefore, in order to optimise medical exposures in children, it is essential to develop quality criteria specifically adapted to paediatric imaging that can be used throughout Europe. With the help of the European Commission, the European Network of Paediatric Radiologists (ENPR), has laid out the status of paediatric radiology in Europe and then elaborated European Guidelines on Quality Criteria for Diagnostic Radiographic Images in Paediatrics. The applicability of the quality criteria has been checked in large European trials involving about 160 X ray departments. These quality criteria are currently being extended to include paediatric fluoroscopy and CT. (author)

[en] We have realized 150 μmx150 μm pixels using ion implantation followed by photolithography, metallic contact evaporation and chemical etching on about 200 μm thick GaAs epitaxial layers. These layers were grown on n⁺ and p⁺ substrates by an already described Chemical Reaction technique, which is economical, non-polluting and can attain growth rates of several microns per minute. The mesa p⁺/i/n⁺ pixel were characterized using current-voltage and capacitance-voltage measurements. The charge collection efficiency was evaluated by photoconductivity measurements under typical conditions of standard radiological examinations

[en] The total measured dose-area product (DAP), fluoroscopic screening time and the number of radiographic exposures were surveyed in a study on micturating cystourethrography (MCU) performed in 1997/1998 in 12 children's clinics in seven European countries. The examination technique and, consequently, total DAP varied widely within and between radiology departments. The evaluation of image quality of original radiographic exposures from the MCUs also showed a wide variation which was not correlated to dose. The quality criteria developed for and used for the MCU in this study proved to be useful for evaluation of spot film images. The wide variations in technique, dose and image quality, even for the relatively homogeneous infant group, indicate the necessity of further optimisation in fluoroscopy. (author)

[en] CT with high dose intravenous injection of iodine can objectivate, the hourglass extension of paraspinal tumors without subarachnoid space opacification. This extradural component of a tumor was seen in 21 children (11 neuroblastomas, 3 non Hodgkin lymphomas, 2 teratomas, 1 Hodgkin, 1 Ewing, 1 sarcoma, 2 metastases). There were 2 cervical, 4 thoracic, 6 abdominal, 9 pelvic tumors. Myelography is not mandatory. Contrast CT should be sufficient. It allows direct visualization of the tumor and of its intraspinal extension

[en] We report one case of multilocular cyst of the kidney in one year and three months female infant who underwent echography, computed tomography and MRI before surgery. MR image accurately reflect the morphology of the tumor: the capsule is hypointense on T1-weighted images, the septa show moderate enhancement with intraveinous contrast. Varied intensities from fluid in the visualized locules presumably represent different concentration of proteins. MR imaging features are highly suggestive but non pathognomonic of the disease. Positive diagnosis always require histology. (authors). 7 refs., 7 figs

[en] The authors report eight cases of biliary duct rhabdomyosarcoma in children, examined by US and CT. There were five boys and three girls, aged 2 to 17 years. At presentation, US demonstrates the tumor mass within the liver or the hepatic hilum; it allows measurement of it and defines the relationship with portal vessels, biliary tract and other important structures. CT complements the US evaluation and determines operability. As US and CT cannot assess the histologial origin of the tumor, a biopsy is mandatory before treatment. If complete surgical excision does not seem possible, percutaneous biopsy is preferrable to incomplete excision and its possible complications. During the follow-up period, US can be repeated to measure tumor regression under chemotherapy. After surgery, CT seems preferable because of gas interposition. Both US and CT proved to be valuable for the early detection of local recurrence. The prognosis of these tumors remains bad. However, with more aggressive and hopefully more efficient chemotherapy a precise evaluation of the tumor extension by US and CT is very important. Surgery will then be performed only on localized tumors or on residual masses after chemotherapy. (orig.)

[en] The authors report 18 cases of pelvic rhabdomyosarcomas in children examined at presentation and followed on US and CT. There were 11 boys, 7 girls; tumor location was bladder, prostate or uterus in 12, perineum in 4, buttock in 2. US is good to define tumoral extension within the bladder CT is better to delineate the extension outside the bladder and regional spread to iliac nodes. CT is the only useful examination for perineal tumors. During chemotherapy US can be frequently repeated to appreciate tumoral regression and to give measurement of the mass. Preoperative CT should be performed when tumoral regression seems sufficient to permit complete tumoral excision without pelvic exanteration. Correlation between US and CT and surgical findings proved to be good. US and CT are also very useful in the follow-up when the child has finished treatment as it can demonstrate a local recurrence before clinical symptoms appear. However, post-surgical and post-radiation changes may be difficult to recognize. These aspects are discussed. (orig.)

[en] We report 2 cases of thoracic neural crest tumors complicating the course in patients with Beckwith-Wiedemann syndrome (BWS). In the first patient, a thoracic neuroblastoma was fortuitously discovered at age 3 months on a chest film prior to a partial glossectomy. In the follow-up left nephroblastoma and a right kidney simple cyst appeared. In the second patient, a thoracic tumor which proved to be a mature ganglioneuroma was discovered at age 4 years on a follow-up spinal radiograph. Although less frequent than nephroblastoma and/or adrenal tumors, the occurrence of thoracic neuroblastoma in BWS suggests that periodic chest radiograph and assays of HVA, VMA and Dopamine should be included in the follow-up protocol. (orig.)

[en] Six patients with eosinophilic granuloma were studied retrospectively in order to correlate the MRI appearances with the pathology. Ages ranged from 2 years 6 months to 11 years. The bones involved were the humerus, ulna, radius, femur, clavicle and ilium. Plain films, MRI and pathology specimens were obtained. A lytic lesion with indistinct margins, endosteal erosions and periosteal reaction was seen in all cases on plain radiographs. Bone marrow signal was decreased on T1-weighted images and increased on T2-weighted images throughout the bony lesion in all cases. T2-weighted images showed extensive soft-tissue abnormalities suggesting inflammatory changes in four cases. In two cases abnormalities were limited. Extensive changes correlated histologically with an early phase lesion. Localized minor changes were associated with a mid-phase lesion. Inflammatory soft-tissue changes could be associated with eosinophilic granuloma. The size of the soft tissue mass correlated well with the activity of the bony lesion. (orig.)