Biomedical subjects
N R Bees
Publications and source records attributed to N R Bees.
Renal angiography using carbon dioxide.
The many advantages of carbon dioxide (CO2) angiography in the investigation of renal arterial disease include an absence of both nephrotoxicity and allergic reactions. An automated delivery system facilitates injection of CO2 whilst ensuring that there is no contamination of the injection with air. We report our initial experience using a prospective study of this delivery system in 47 patients referred for renal angiography, and assess diagnostic image quality and adverse reactions to CO2 angiography using the automated delivery system. The majority (37/47; 79%) of angiograms were of diagnostic quality and there were no significant adverse reactions in response to the CO2 contrast agent.
Carbon dioxide angiography of the lower limbs: initial experience with an automated carbon dioxide injector.
Carbon dioxide (CO2) has been used as an arterial contrast agent since 1971. The development of digital subtraction angiography and an automated CO2 injector has increased the practicability and safety of using CO2 routinely. Sixty-three patients had lower limb and/or renal arteriograms performed over a 6-month period using CO2 in comparison with iodinated contrast medium. The majority (mean 74%, range 53-86%) of non-selective studies were diagnostic to the level of the popliteal artery, and 84% of selective lower limb studies were diagnostic. No serious complications occurred. The contrast and spatial resolution of CO2 digital subtraction arteriography (CO2DSA) was not consistently as good as iodinated contrast medium in peripheral lower limb or renal studies. However, due to the absence of allergic reactions and lack of nephrotoxicity, CO2 is a diagnostic alternative to iodinated contrast medium in selected patients.
Trends in the use of pelvimetry techniques.
Assessment of maternal pelvic dimensions is usually considered necessary where vaginal delivery is contemplated in a breech presentation or if reduced pelvic dimensions are suspected in a current or previous pregnancy. Pelvimetry techniques include computed tomography (CT), conventional radiography, digital fluorography and magnetic resonance imaging (MRI). The first three techniques result in a radiation dose to mother and fetus which, depending on how the technique is performed, can vary by up to 40-fold. Of the techniques using X-rays, CT pelvimetry with a lateral scanogram generally gives the lowest radiation dose and conventional radiography using an air gap technique with a single lateral view is a relatively low-dose alternative where CT is not available. A questionnaire was sent to 227 hospitals during 1993 and 1996 to assess whether there was a move towards lower dose techniques of pelvimetry. The results show a trend away from conventional pelvimetry (48.4% in 1993 to 28% in 1996) with a small proportion of centres using MRI (4%) in 1996. Of the centres still using conventional pelvimetry, relatively few were using a low-dose air-gap technique (2.1% in 1993 to 10.9% in 1996). An increasing majority of centres were using one-view CT (69.3% in 1993 and 80.4% in 1996) but a significant proportion were still performing more than one view. This study shows that there was a move towards lower dose techniques of pelvimetry but that there were still many hospitals that had not implemented a policy of reducing radiation exposure in these patients.
Neonatal thymic haemorrhage.
Thymic haemorrhage in a neonate is an exceedingly rare condition. A case is presented of a neonate presenting at birth with cyanosis, respiratory distress and an anterior mediastinal mass. The radiological findings are demonstrated. After surgical excision and histopathological examination the lesion was found to be spontaneous haemorrhage into normal thymic tissue. Spontaneous thymic haemorrhage should be considered in any neonate developing acute respiratory distress with widening of the mediastinum and pleural effusion on chest radiography. Ultrasound may be used to support the diagnosis.
Gastric malignant schwannoma in a child.
Malignant schwannoma (malignant peripheral nerve sheath tumour, MPNST) is a high grade sarcoma with a potential for local recurrence and distant metastasis that may occur at any site in the body where there is neural tissue. MPNST is rare in children and is unreported in the stomach in the paediatric age group. MPNST presents either as an expanding mass, with or without pain, or in the gastrointestinal tract with haemorrhage or obstruction. Many cases occur without evidence of neurofibromatosis but thers is a reported association between MPNST and neurofibromatosis of up to 50%. MPNST has a higher incidence at sites of previous irradiation. Treatment is by complete surgical excision. Radiology is of value in initial diagnosis and staging prior to surgery. The definitive diagnosis is made on the histopathological appearance and immunohistochemical profile. The findings on barium meal, abdominal ultrasound and CT are presented.