摘要:

AbstractDirect coronal computed tomography (CT) of the temporomandibular joint (TMJ) was performed in 26 patients with rheumatoid arthritis (RA) and 26 control subjects. Erosions and cysts of the mandibular condyle had a significantly higher frequency in the RA group than in the control group (p<0.05) but there was no significant difference in the incidence of other abnormalities. Bone changes were bilateral in RA. A wide range of CT abnormalities was present in patients with RA and in the control group. There are no CT abnormalities specific for RA, but the incidence of erosions and cysts of the mandibular condyle was significantly higher in the RA group and should suggest the diagnosis.

DOI:10.1259/0007-1285-65-779-955

出版商:The British Institute of Radiology    

年代:1992

数据来源: WILEY

摘要:

AbstractTo study the mechanism of the pain produced by contrast media (CM) in peripheral arteriography, we examined the direct effects of low concentrations (1.85–100 mg I/ml) of CM (diatrizoate, iopamidol, ioxaglate, and iotrolan) on helically cut strips of canine blood vessels taken from six different regions. We found that: (a) low concentrations of CM induced vasoconstriction. (b) This occurred immediately after the application of CM and produced sustained constriction, (c) The constriction produced in arteries was dose-dependent, (d) The production and intensity of constriction in the arterial strips differed as follows: cranial mesenteric artery>renal artery>femoral artery>common carotid artery>thoracic aorta>coronary artery. The effects of the CM were, in order of magnitude: diatrizoate>iopamidol>ioxaglate>iotrolan. Differences between CM corresponded with the differences in osmolality of the CM solutions, (e) Low concentrations of meglumine and mannitol also produced vasoconstriction. (f) Constriction caused by all drug samples used was reversible, but the process of relaxation to the original tension was much slower in CM-treated arterial strips than in the other strips. From these results, we confirmed that the incidence and degree of vasoconstriction produced by all drug samples used in this experiment depended on solution osmolality, rather than on chemotoxicity or ionicity. We discuss the physiological mechanism of these results and stress the importance of CM hyperosmolality in vasoconstriction and vascular pain production.

DOI:10.1259/0007-1285-65-779-961

出版商:The British Institute of Radiology    

年代:1992

数据来源: WILEY

摘要:

AbstractPercutaneous drainage of splenic abscesses has not yet become a common procedure due to the potential risk of bleeding and the danger of damage to neighbouring organs. We present our experience of percutaneous drainage in eight patients with splenic abscesses. Four patients were treated by therapeutic percutaneous needle aspiration of the fluid collection, and four by percutaneous trocar catheter insertion. All procedures were guided by ultrasound or computed tomography. The procedure was successful in all eight patients with no complications.

DOI:10.1259/0007-1285-65-779-968

出版商:The British Institute of Radiology    

年代:1992

数据来源: WILEY

摘要:

AbstractTwo-view mammography is generally preferred as an initial screening examination because the number of missed carcinomas and false positive results in one-view mammography is considered too large. The present review was performed to assess the difference in screening quality between one- and two-view mammography. Nineteen previous studies were reviewed and differences in sensitivity as well as specificity between two-view and one-view mammography were calculated. The results ranged from –5.7% to 19.4% (median 3.9%), and 2.7% to 36.1% (median 14.8%), respectively, and indicate a higher screening quality of two-view mammography. However, in the studies considered there is a large variation in study population, screening tests used and assessment of disease outcome, which makes the numerical results less conclusive. None of the studies provided adequate information for deciding whether two-view mammography in baseline screening for breast cancer is preferable to one-view mammography. If a screening programme using one-view mammography has already achieved high sensitivity and specificity, the value of an additional craniocaudal view is only marginal.

DOI:10.1259/0007-1285-65-779-971

出版商:The British Institute of Radiology    

年代:1992

数据来源: WILEY

摘要:

AbstractThis paper reviews the clinical, sonographic and pathological findings of 20 children with thyroid carcinoma in an attempt to determine the value and limitations of sonography in thyroid neoplasms in this age group. Although sonography is an excellent technique for the evaluation of thyroid disorders and masses, certain limitations must be kept in mind. Microscopic foci of tumour might be missed and sonography cannot predictably differentiate benign from malignant disease. Previous radiation exposure should increase the level of suspicion for malignancy.

DOI:10.1259/0007-1285-65-779-977

出版商:The British Institute of Radiology    

年代:1992

数据来源: WILEY

摘要:

AbstractThe aim of this study was to determine the prevalence of enlarged mediastinal lymph nodes in systemic sclerosis (SSc) and relate this to the extent of pulmonary disease and disease activity as judged by high resolution computed tomography HRCT). The HRCT scans of 78 patients with SSc were reviewed. The extent of lung disease and HRCT pattern were analysed and CT scans examined on soft tissue window settings for evidence of mediastinal lymph node enlargement. Sixty six (85%) patients had evidence of lung involvement on CT. Enlarged mediastinal lymph nodes were present in 21 (32%) patients with lung involvement but in only 1 (8%) patient without. The prevalence of enlarged mediastinal nodes increased with more extensive lung involvement on CT (p<0.025), but correlated poorly with the type of CT appearance and concurrent erythrocyte sedimentation rate. Mediastinal lymph node enlargement occurs frequently in patients with SSc, particularly if lung involvement is extensive.

DOI:10.1259/0007-1285-65-779-983

出版商:The British Institute of Radiology    

年代:1992

数据来源: WILEY

摘要:

AbstractA total of 104 women with singleton pregnancies who were delivered between 37 and 42 weeks gestation had ultrasound scans during the fortnight before delivery. The biparietal diameter (BPD), abdominal circumference (AC) and femur length (FL) were measured in all cases. Estimation of fetal weight (EFW) was done by four different methods: using AC alone, AC/BPD, AC/FL and AC/BPD/FL. Results were compared with values of actual birthweights at delivery. There was no significant difference between the mean birthweights of the 47 boy and 57 girl fetuses studied. The EFW(Shepard)method showed the least bias overall: mean percentage error 1.7%, standard deviation (SD) 10.6%. The other three methods significantly underestimated birthweights on average: EFW(Deter), mean error 2.2%, SD 9.3%,p<0.02; EFW(Campbell), mean error 5.4%, SD 9.5%,p<0.001; EFW(Hadlock), mean error 5.6%, SD 9.3%,p<0.001. The percentage error in each group was significantly negatively correlated (p<0.001) with the scan–delivery interval. Two new equations were generated which gave more accurate predictions for the cases under study using AC, BPD and FL as a combination and also in addition to scan–delivery interval (SDI) in days.

DOI:10.1259/0007-1285-65-779-987

出版商:The British Institute of Radiology    

年代:1992

数据来源: WILEY

摘要:

AbstractThe use of thin K-edge filters has been found to reduce considerably the radiation dose in intra-oral radiography. The aim of this study was to investigate the effect of nitration on the skin entrance dose and several sites (representing organs or areas of interest within the head) along the central beam axis, at other points within the primary beam and at two points just outside the primary beam. The subject was a sliced head phantom (a human skull embedded in tissue-equivalent material) which was exposed to X rays from a conventional dental X-ray unit in the range of tube voltage 55–85 kVp for each of four filter systems. These were 2.7 mm of aluminium alone (the existing total filtration) or with an added 0.1 mm erbium, 0.1 mm yttrium or 0.05 mm niobium metal foils. Measurements of radiation dose were made using thermoluminescent dosemeters (TLD rods) and were adjusted to simulate the exposure resulting from a typical dental radiograph of a maxillary molar. The results suggest that the use of thin K-edge filters significantly reduces the entrance skin dose and to a certain extent reduces the total dose imparted to the head. However, the dose to the ipsilateral orbit at higher tube voltages may be increased.

DOI:10.1259/0007-1285-65-779-990

出版商:The British Institute of Radiology    

年代:1992

数据来源: WILEY

摘要:

AbstractThis study has estimated the distribution of diagnostic X-ray doses amongst individuals in the British population by sampling the records kept by general practitioners (GPs) on their patients and the records held by the radiology department of a district general hospital. Deceased patients were chosen in the former case in order to evaluate the dose acquired over a complete lifetime. In each case, several hundred records were sampled. The GP data obtained have enabled an estimate to be made of the likelihood of reaching various dose levels in a lifetime. It is estimated that about 1% of the population has received a lifetime effective dose-equivalent of more than 100 mSv. The largest cumulative dose revealed by the samples of GP and radiology department records was about 200 mSv. The GP data have also shown that the last year of life sees a four-fold increase in the number of X-ray examinations experienced compared with the previous 9 years. The hospital data have allowed an estimate to be made of current rates of dose acquisition amongst the population of a District Health Authority.

DOI:10.1259/0007-1285-65-779-996

出版商:The British Institute of Radiology    

年代:1992

数据来源: WILEY

摘要:

AbstractDuring fluoroscopy the examiner is usually protected by a radiation-reducing body shield, leaving the thyroid unprotected. The fact that the thyroid is located in a region of the neck usually covered by the shirt collar led to the idea of designing a tie with lead core, providing easy and “decorative” reduction of the radiation dose. Sonographic examinations were carried out in 20 volunteers (10 men, 10 women) to determine the size of the gland and its coverage by such a tie. The reduction of the surface and organ dose was assessed using film dosimetry with scattered radiation, the body of the examiner being simulated by an Alderson phantom. On average 88% of the thyroid gland surface area was covered. Surface dose was reduced to 1%, and organ dose to 10% of the value without the protection tie.

DOI:10.1259/0007-1285-65-779-1003

出版商:The British Institute of Radiology    

年代:1992

数据来源: WILEY