DOI:10.1259/bjr.71.849.10195001

出版商:The British Institute of Radiology    

年代:1998

数据来源: WILEY

DOI:10.1259/bjr.71.849.10195002

出版商:The British Institute of Radiology    

年代:1998

数据来源: WILEY

摘要:

A prospective, double-blind study of 392 patients randomized into four groups was performed to establish whether diagnostic intravenous urograms could be obtained with a lower dose of iodine when using the dimeric, non-ionic contrast medium iodixanol compared with the monomeric, non-ionic iohexol. Patients received iodixanol or iohexol containing either 9 or 12 g of iodine (gI). The primary parameter was the diagnostic quality of the 6 min film, assessed in a blinded fashion, by consensus, by four radiologists. Iodixanol at both doses was diagnostic in over 90% of cases. Iohexol was only diagnostic in 74% (9 gI) and 81.8% (12 gI). Pairwise comparisons revealed that iodixanol 9 gI was significantly better than both iohexol 9 gI (p = 0.0005) and 12 gI (p = 0.014). No significant difference was present for different doses within the same contrast medium group. Iodixanol resulted in poorer bladder distension than iohexol. Iodixanol caused significantly less discomfort than iohexol.

DOI:10.1259/bjr.71.849.10195003

出版商:The British Institute of Radiology    

年代:1998

数据来源: WILEY

摘要:

Non-ionic dimers induce less diuresis than non-ionic monomers, resulting in increased opacification of the urinary tract in intravenous (i.v.) urography. This double blind, comparative, randomized, parallel trial compared the efficacy of iodixanol (non-ionic dimer) and iopromide (non-ionic monomer) in 100 patients with mild to moderate renal insufficiency (serum creatinine of 135 to 265 mumol l-1) who underwent i.v. urography. A total dose of 600 mgI kg-1 bw of iodixanol (320 mgI ml-1) or iopromide (300 mgI ml-1) was injected. Radiographs were blindly evaluated by three radiologists who analysed different parameters (renal border visualization, nephrogram density, calyceal filling and density, papillary blush detection, delineation of collecting ducts, renal pelvis opacification, visualization of ureters, bladder density, bladder distention). Densitometric evaluation on the renal pelvis and bladder was also performed. Iodixanol showed better filling and density of the calyces (p = 0.004), more frequent detection of papillary blush (p = 0.003) and better opacification of the renal pelvis (p = 0.006). No significant differences between the two contrast media were found in regard to other parameters. In conclusion, the results confirmed theoretical expectations. The non-ionic dimer iodixanol is to be preferred to a non-ionic monomer such as iopromide in i.v. urography on patients with impaired renal function.

DOI:10.1259/bjr.71.849.10195004

出版商:The British Institute of Radiology    

年代:1998

数据来源: WILEY

摘要:

Previous studies have suggested that the upper limit of the thinnest portion of the pericardium is 3-4 mm using 10 mm CT slices. However, these studies suffered from small sample sizes, long data acquisition times and unconventional viewing parameters. We have measured the width of the thinnest portion of the normal pericardium using 10 mm (100 patients) and 1 mm (100 patients) high resolution CT (HRCT) slices with modern CT equipment and fixed mediastinal window settings (400/20). The pericardium was identified in all patients and was best seen anterior to the heart. The pericardium is exceptionally well seen using 1 mm HRCT slices and this may be the optimal technique for visualization of the pericardium. The upper limit of the thinnest portion of the normal pericardium (mean value + 2 SD) was 1.2 mm (10 mm CT slices) and 0.7 mm (1 mm HRCT slices). These values are substantially lower than those previously reported and in line with anatomical findings.

DOI:10.1259/bjr.71.849.10195005

出版商:The British Institute of Radiology    

年代:1998

数据来源: WILEY

摘要:

A soft tissue expander is surgically inserted into the body to displace radiosensitive organs from the treatment field in a small number of patients receiving radiotherapy for musculoskeletal sarcoma. MRI is routinely used to monitor the response to the radiotherapy, local recurrence and complications of treatment. This study retrospectively reviews MRI of soft tissue expanders in seven patients with musculoskeletal sarcomas; six arising in the pelvis and one in the retroperitoneum. In the absence of an appropriate clinical history, the soft tissue expander may be mistaken for a pathological fluid collection such as abscess, post-operative seroma or even recurrent tumour. MRI of the soft tissue expanders and potential errors in image interpretation are illustrated.

DOI:10.1259/bjr.71.849.10195006

出版商:The British Institute of Radiology    

年代:1998

数据来源: WILEY

摘要:

Dried fish bones from eight species of Malaysian fish were placed in an animal cadaver at four sites (tonsil, valleculae, larynx and oesophagus) and radiographed using a double and a single film-screen combination. The use of the single film-screen combination resulted in visibility of all fish bones placed in the larynx, two of which were not visible on the double film-screen combination. There was a 50% increase of the visibility of the fish bones in the oesophagus using the single film-screen combination. The difference in dose and cost between the two different film-screen combinations was not significant.

DOI:10.1259/bjr.71.849.10195007

出版商:The British Institute of Radiology    

年代:1998

数据来源: WILEY

摘要:

Bone densitometry using dual energy X-ray absorptiometry (DXA) is frequently used to diagnose osteoporosis and to identify patients at risk of later fractures. The parameters of interest are bone mineral content (BMC) and bone mineral areal density (BMD). Bone densitometry results have a large overlap between normals and patient with fractures. This would suggest that other factors are important for the development of fractures or that bone densitometry is not used optimally. It is generally believed that the conversion of BMC to BMD by division of the former by the projected bone area is a good normalization procedure. Other normalization procedures have been attempted in the past with little success. We hypothesized that this might be due to a blurring effect of time since menopause, and that body size could be demonstrated to have an effect on measured BMC and BMD, if this time effect could be eliminated. The results of this study, comprising 1625 early post-menopausal women studied at virtually the same time since menopause, confirm that this is the case. Body surface area was the parameter among conventional body size variables showing the highest correlation with BMC and BMD. It was clearly shown that low values of BMD were seen more often in the lowest than in the highest body surface area quartile. The difference between quartiles was statistically significant. Simple division of BMC by actual body surface area or division of BMD by the square root of body surface removed the uneven distribution between the body surface area quartiles for lumbar spine and femoral neck measurements, and reduced it at peripheral measuring sites. It is suggested that BMC and BMD of the lumbar spine and the femoral neck should be normalized as described to avoid overdiagnosis of osteoporosis in persons of petite body stature and underdiagnosis in tall ones.

DOI:10.1259/bjr.71.849.10195008

出版商:The British Institute of Radiology    

年代:1998

数据来源: WILEY

摘要:

Ytong is a widely used building material. The X-ray attenuation properties of Ytong for broad beam geometry conditions and for tube potentials in the 50-140 kVp range are investigated. Comparisons with published data for concrete and other building materials are made. The results suggest that Ytong is not suitable for primary X-ray shielding in common diagnostic installations. However, walls of Ytong, typically 15-20 cm thick, may offer adequate protection in dental and mammography installations, as well as in low workload diagnostic installations as a secondary barrier.

DOI:10.1259/bjr.71.849.10195009

出版商:The British Institute of Radiology    

年代:1998

数据来源: WILEY

摘要:

The optimization of optical density in film-screen mammography is crucial in attaining good image quality. While a target range for film optical density of 1.4-1.8 has been recommended for centres participating in the National Health Service Breast Screening Programme (NHSBSP), past investigations have shown that combinations of mammography film and screen and processor conditions can have various optimum densities, some of which are outside this recommended range. The optimum optical density of the film/screen/processor conditions combination used at our institution (the Kodak MIN-RM/MIN-R combination designed for standard-cycle processing) was evaluated using a breast detail phantom study. It was found that the optimum optical density was 1.25 OD. We recommend that an individual institution determines the optimum optical density for the film-screen combination it uses and the processing conditions specific to it.

DOI:10.1259/bjr.71.849.10195010

出版商:The British Institute of Radiology    

年代:1998

数据来源: WILEY