Radiation Protection of the Child from Diagnostic Imaging.

In recent years due to the technological advances in imaging techniques, which have undoubtedly improved diagnostic accuracy and resulted in improved patient care, the utilization of ionizing radiation in diagnostic imaging has significantly increased. Computed tomography is the major contributor to the radiation burden, but fluoroscopy continues to be a mainstay in paediatric radiology. The rise in the use of ionizing radiation is of particular concern with regard to the paediatric population, as they are up to 10 times more sensitive to the effects of radiation than adults, due to their increased tissue radiosensitivity, increased cumulative lifetime radiation dose and longer lifetime in which to manifest the effects. This article will review the estimated radiation risk to the child from diagnostic imaging and summarise the various methods through which both the paediatrician and radiologist can practice the ALARA (As Low As Reasonably Achievable) principle, which underpins the safe practice of radiology. Emphasis is on the justification for an examination, i.e. weighing of benefits versus radiation risk, on the appropriate utilization of other, non-ionizing imaging modalities such as ultrasound and magnetic resonance imaging, and on optimisation of a clinically indicated examination. It is essential that the paediatrician and radiologist work together in this decision making process for the mutual benefit of the patient. The appropriate practical application of ALARA in the workplace is crucial to the radiation safety of our paediatric patients.

Embryonal rhabdomyosarcoma of the omentum: two cases occurring in children.

Rhabdomyosarcoma is a soft-tissue malignancy that represents approximately 4-8% of all solid tumours in children and commonly arises from the head and neck and genitourinary system. Intraperitoneal rhabdomyosarcoma, in particular with omental involvement, has been rarely reported in the literature. Furthermore, reports of omental rhabdomyosarcoma of embryonal origin do not exist, to our knowledge. We report two cases of omental embryonal rhabdomyosarcoma affecting children and illustrate the imaging characteristics of this rare tumour.

Imaging features of von Hippel-Lindau disease.

von Hippel-Lindau (VHL) disease is a rare, autosomal dominantly inherited multisystem disorder characterized by development of a variety of benign and malignant tumors. The spectrum of clinical manifestations of the disease is broad and includes retinal and central nervous system hemangioblastomas, endolymphatic sac tumors, renal cysts and tumors, pancreatic cysts and tumors, pheochromocytomas, and epididymal cystadenomas. The most common causes of death in VHL disease patients are renal cell carcinoma and neurologic complications from cerebellar hemangioblastomas. The various manifestations can be demonstrated with different imaging modalities such as ultrasonography, computed tomography, magnetic resonance imaging, and nuclear medicine. Although genetic testing is available, the manifestations of the syndrome are protean; therefore, imaging plays a key role in identification of abnormalities and subsequent follow-up of lesions. It is also used for screening of asymptomatic gene carriers and their long-term surveillance. Screening is important because the lesions in VHL disease are treatable; thus, early detection allows use of more conservative therapy and may enhance the patient's length and quality of life. A multidisciplinary team approach is important in screening for VHL disease.

Coagulopathy as a presenting feature of Wilms tumour.

UNLABELLED: Wilms' tumour (nephroblastoma) is the most common intrarenal malignancy of childhood. The most common presentation is of an asymptomatic abdominal mass (more than 80%), usually discovered incidentally. Abdominal pain occurs in 30% to 40% of patients, and hypertension, frank haematuria and fever are found in 5% to 30%. A lesser known presentation of Wilms' tumour is that of acquired von Willebrand syndrome (AVWS). This has a well recognised association with malignancies, most commonly with monoclonal gammopathies, lymphoproliferative and myeloproliferative disorders, and less commonly with solid tumours. In this article we report two cases of AVWS in patients with Wilms' tumour, the discovery of which led to a retrospective study to determine the incidence of acquired von Willebrand syndrome and coagulopathy in general in association with Wilms' tumour. We reviewed the case notes of 65 children diagnosed with Wilms' tumour between 1996 and 2001 and referred to a haematology/oncology unit within a tertiary referral centre. We observed an incidence of abnormal clotting in 16/65 and AVWS in 2/65. Treatment of the coagulation abnormalities in these two patients was with fresh frozen plasma for both and also von Willebrand factor concentrate for one. In both cases resolution of the coagulation abnormalities occurred upon treatment of the tumour. CONCLUSION: we emphasise the importance of a routine coagulation screen in every patient who presents with a possible Wilms' tumour.