DOI:10.1259/bjr.73.870.10911777

出版商:The British Institute of Radiology    

年代:2000

数据来源: WILEY

摘要:

Teleradiology is the electronic transmission of radiographic images from one geographic location to another for the purposes of diagnosis and/or consultation. It raises interesting ethical and practical issues which have received relatively little attention in the radiology or ethics literature to date. These include confidentiality, data security and technological reliability, consent, competence, interprofessional and professional-patient relationships, and the organization of medical services. This paper reviews these issues, discussing how far these are new concerns in radiological practice, and makes suggestions for minimum ethical and professional standards for teleradiological practice.

DOI:10.1259/bjr.73.870.10911778

出版商:The British Institute of Radiology    

年代:2000

数据来源: WILEY

摘要:

The occurrence of significant mediastinal lymphadenopathy together with pleural effusion or empyema inevitably raises concern about the presence of intrathoracic malignancy or granulomatous disease. Lymph node enlargement may also occur when pneumonia is accompanied by a parapneumonic effusion or empyema. Features that allow "benign" lymph node enlargement to be distinguished from malignant causes have not previously been determined. The present study aims to establish the CT characteristics of enlarged nodes in parapneumonic effusion. The appearances of mediastinal lymph nodes were recorded in 50 consecutive patients with parapneumonic effusion/empyema. 18 (36%) had mediastinal lymphadenopathy (node size greater than 1 cm). The mean number of enlarged nodes was 1.9 (range 1-3) and the mean size was 1.4 cm (2 cm maximum). Seven patients had a single involved site, nine patients two sites and two patients three sites. The right paratracheal area was most commonly involved and the subcarinal area contained the largest nodes. The presence of enlarged nodes did not correlate with biochemical and microbiological stage of pleural infection, length of history, or extent of consolidation. This study shows that mediastinal lymphadenopathy is commonly associated with parapneumonic effusion and that multiple sites may be involved. The degree of enlargement is moderate although lymphadenopathy of greater than 2 cm size should raise the possibility of other pathology.

DOI:10.1259/bjr.73.870.10911779

出版商:The British Institute of Radiology    

年代:2000

数据来源: WILEY

摘要:

The aim was to investigate the regional and systemic haemodynamic consequences of bolus injection of fluids with different physical properties in the course of routine aortography. Iopamidol was compared with an equiosmolar solution of mannitol and with a 0.9 N saline solution. Continuous blood flow and Pulsatility Index (PI), as an index of regional vascular resistance, were measured by Doppler technique. Finger arterial pressure and heart rate were monitored at the time and for 3 min following each intraaortic bolus injections. The patients who underwent routine aortography were grouped according to the site of the flow measurements: common femoral artery, common carotid artery and brachial artery. Flow changes induced by the bolus infusion were evident for all the fluids but only at the femoral artery level. After an immediate (3 +/- 2 s) and brief (2 +/- 2 s) but marked reduction of flow and in-phase increase of PI following the bolus, further haemodynamic changes were observed only in the femoral artery, with a peak at 35 +/- 10 s and returning to baseline values after 70 +/- 15 s, in terms of both increased mean blood velocity and decreased PI. Saline and mannitol induced overall blood velocity alterations of 54% and 80%, respectively, and PI reductions of 44% and 57% compared with those induced by iopamidol. In the other vascular areas there was only a 17 +/- 2% increase of the physiological early diastolic backflow at the brachial artery level. Blood pressure decreased and heart rate increased in phase with the flow changes of the femoral artery. In conclusion: (1) a dramatic rheodynamic perturbation at the site of injection induces a vasodilating stimulus; (2) the haemodynamic response following injection results in marked vasodilation of only the tributary vascular bed; (3) flow steal may occur from other beds towards the lower limb vascular beds owing to vascular impedance imbalance; (4) a reduction of systemic arterial pressure is induced in phase with the regional vascular events and a reflex increase of the heart rate; and (5) the physical properties of the injected fluids influence the intensity of the perturbation, although the decisive triggering factor is the counterflowing bolus per se.

DOI:10.1259/bjr.73.870.10911780

出版商:The British Institute of Radiology    

年代:2000

数据来源: WILEY

摘要:

Ultrasound of the carotid artery identifies the hypoechoic intima-medial layer (IML). Increased granularity of the IML has been associated with early atherosclerosis. The aim of the study was to assess the reproducibility and observer agreement of a computer-based program measure of IML granularity. Ten healthy adult volunteers (median age 32 years, range 18-34 years) were examined twice, 2 weeks apart, with a 7 MHz linear transducer using standardized imaging settings, by two observers. Images of both common carotid arteries were digitized and analysed on a customized computer program. The ratio (averaged over a 1 cm length of arterial wall) of the lowest pixel brightness in the IML to the maximum pixel brightness in the intima-medial interface was determined. Overall mean intima-medial reflectivity (IMR) indices for the two observers were 0.761 +/- 0.101 and 0.707 +/- 0.103, with single determination standard deviation values of 0.090 and 0.073, respectively. For interobserver calculations, the overall mean IMR index for both sessions was 0.734 +/- 0.107, with a single determination standard deviation of 0.067. Comparison with the intima-medial thickness (IMT) showed an inverse correlation (r = -0.72). This method of quantifying the reflectivity of the IML demonstrates good reproducibility in subjects with normal IMT measurements. The technique may be of value in identifying subjects at high risk of atherosclerosis but with IMT still within the normal range.

DOI:10.1259/bjr.73.870.10911781

出版商:The British Institute of Radiology    

年代:2000

数据来源: WILEY

摘要:

It has been suggested that tungsten embolisation coils in intracranial aneurysms may dissolve in situ. These coils are also used, in much larger quantities, for the occlusion of larger vessels outside the cranium. This study was performed to investigate whether tungsten embolisation coils may become degraded in vivo and to examine whether this is radiographically evident on medium-term follow-up. 10 patients who had undergone aortic stent-graft repair of an abdominal aortic aneurysm (8 male and 2 female, mean age 69.7 years) and 10 age- and sex-matched controls were studied. The study group had also received an average of 64 cm of tungsten coil either to prevent or to treat an endoleak. Whole blood, serum and urine tungsten levels were assayed. Immediate post-operative and follow-up abdominal radiographs were reviewed by two consultant vascular radiologists to detect visible changes in the coils. Whole blood, serum and urine levels of tungsten were highly and significantly elevated (p<0.001) in the study group compared with the controls. No radiographic changes in the coils were seen at an average of 16.7 months. In conclusion, tungsten embolisation coils dissolve in humans but radiographic changes are not apparent on medium-term follow-up. The clinical significance of these findings is uncertain but long-term follow-up is needed.

DOI:10.1259/bjr.73.870.10911782

出版商:The British Institute of Radiology    

年代:2000

数据来源: WILEY

摘要:

We retrospectively reviewed 104 dacryocystograms carried out on 72 patients who had previously undergone dacryocystorhinostomy, to assess the diagnostic contribution of the radiological investigation in patients with persistent or recurrent symptoms. In patients whose symptoms were referable to the operated side, dacryocystography was performed as part of further pre-operative assessment. In 42% of these patients it demonstrated an anatomical or physiological abnormality that explained the symptoms. However, no clear reason for the recurrence of symptoms was demonstrated in 58% of cases.

DOI:10.1259/bjr.73.870.10911783

出版商:The British Institute of Radiology    

年代:2000

数据来源: WILEY

摘要:

The case for radiographer abnormality highlighting in the Accident and Emergency (A&E) department is well documented. Following evaluative feedback, 280 questionnaires were sent nationally to A&E radiology departments (excluding Northern Ireland). The intent of the survey was to ascertain the viability of constructing a short course in trauma plain film pattern recognition in the axial and appendicular skeleton. Following a highly positive response a course was designed and operated on a workshop basis, being lead primarily by reporting radiographers. The course was evaluated for effectiveness using three identical assessments of 42 films, including 12 positive for trauma. A sample of 22 radiographers who attended the pilot course and subsequent courses throughout 1998/99 undertook the assessment. The assessments themselves were performed at the start and end of the course and 6-10 weeks after completion. Results appear to indicate that a significant improvement in the specificity (p = 0.002) and accuracy (p = 0.005) was achieved following the course. In the light of continuing professional development, the course appears to address the needs of the majority of clinical radiographers working in A&E.

DOI:10.1259/bjr.73.870.10911784

出版商:The British Institute of Radiology    

年代:2000

数据来源: WILEY

摘要:

Mammographic image quality, contrast and dose for a variable tube potential (kVp) technique protocol for film-screen mammography have been investigated. In this protocol, the tube potential is increased for larger breast thicknesses. Comparisons were made with fixed kVp protocols, in which the tube potential is kept constant and the breast thickness compensated for by prolonging the exposure ("fixed kVp" protocol). All measurements were performed on a mammography unit with a molybdenum target and filter. Image quality was quantified by image contrast, image detail detection and the minimum detectable dimension of low contrast objects. It was demonstrated that for a compressed breast thickness of less than about 40 mm, varying the tube potential had a negligible effect upon dose but a significant effect upon image quality. For a compressed breast thickness greater than about 60 mm, the effect of the tube potential upon image quality was much reduced; however, the effect upon dose was significantly greater. The variable kVp protocol takes advantage of this feature to yield a significantly lower dose for thicker breasts with a small reduction in image quality, often only within experimental uncertainty. For an exposure under automatic exposure control, increasing the tube potential from 26 kVp to 30 kVp for a breast of a reference tissue composition (50% adipose and 50% glandular) with a compressed thickness of 60 mm reduced the mean glandular dose from 6 mGy to 3.9 mGy (-35%), but increased the minimum detectable dimension of a low contrast mass from 0.8 (+/- 0.1) mm to 1.1 (+/- 0.1) mm. Adopting a variable kVp protocol led to a median patient mean glandular dose per film of 2.7 mGy, nearly independent of compressed breast thickness. In our survey, the mean age of women presenting for mammography is younger and the mean compressed breast thickness is less than reported from screening centres. This suggests that there will be a higher proportion of denser, glandular tissue in the breasts incorporated within this survey than for surveys from screening centres. The clinical use of the variable kVp protocol allows the extraction from patient data of separate changes in breast composition which are due to patient age and breast thickness. It is concluded that the reference breast tissue composition is not an accurate representation of the women presenting at this centre.

DOI:10.1259/bjr.73.870.10911785

出版商:The British Institute of Radiology    

年代:2000

数据来源: WILEY

摘要:

Well differentiated thyroid cancer is a rare disease in the UK. It is the only cancer which, having metastasized, remains curable by radioisotope therapy with 131I. The main indication for administering repeat doses of 131I is the appearance of abnormal uptake in a whole body scan following diagnostic or therapeutic 131I administration. False positive scans, showing the presence of 131I uptake in the absence of residual thyroid tissue or metastases can occur, although they are uncommon. Unless recognized as a false positive, 131I uptake may result in diagnostic error and lead to administration of an unnecessary therapy dose. We describe a series of nine patients in whom the scans showed false positive uptake of 131I, including cases where the cause of the uptake is still uncertain. We demonstrate the common sites of false positive uptake, discuss the underlying mechanisms and suggest a systematic approach to the interpretation of whole body scans in order to prevent unnecessary treatment with 131I.

DOI:10.1259/bjr.73.870.10911786

出版商:The British Institute of Radiology    

年代:2000

数据来源: WILEY