摘要:

The aim of this study was to compare the efficacy of CO2angiography with that of iodinated contrast angiography for vascular mapping prior to partial nephrectomy for presumed renal cell carcinoma. 13 consecutive patients were studied and all patients underwent selective renal angiography using both CO2and iodinated contrast medium. Digitally subtracted images were acquired and compared. Seven male and six female patients, with a median age of 58 years (range 46–74 years), were examined. On comparing images the main renal artery was visualized in all cases with both contrast agents. The segmental vessels were seen in 7 of 13 CO2studies and 12 of 13 iodinated contrast studies. CO2was also inferior in the depiction of tumour circulation, showing it in 4 of 13 cases compared with 9 of 13 cases using iodinated contrast. It therefore appears that CO2angiography offers no diagnostic advantage and is also inferior to iodinated contrast angiography in the pre-operative vascular mapping of renal tumours.

DOI:10.1259/bjr/15383522

出版商:British Institute of Radiology    

年代:2003

数据来源: WILEY

摘要:

Accurate interpretation of X-ray images is dependent on image viewing conditions. A recent study in Ireland demonstrated that even with the advent of digital departments the majority of images are still viewed using viewing boxes. This investigation aimed to measure average viewing box brightness, percentage uniformity and ambient light levels in radiology and radiographer viewing areas and wards within three major Dublin hospitals. The results were compared with published recommendations by the World Health Organization and Commission of the European Communities. Following analysis of more than 4650 measurements, it was shown that mean values for average viewing box brightness for all departments failed to achieve recommended levels. Only one third of areas met the most lenient guideline for percentage uniformity. Ambient lighting was shown to be unacceptable for ward areas. For all three parameters, radiology areas generally fared best, with wards gaining the poorest scores. Following a 3 min cleaning regimen of viewing boxes, the average brightness and percentage uniformity were improved in 100% and 80%, respectively, of viewing boxes, but average brightness values remained below recommended levels. The importance of comprehensive quality assurance programmes for viewing boxes has been highlighted so that visualization of images is not reduced to sub-optimal levels. The need for consistent and more informative recommendations has been emphasized.

DOI:10.1259/bjr/92036272

出版商:British Institute of Radiology    

年代:2003

数据来源: WILEY

摘要:

Functional MRI (fMRI) may provide a means of locating areas of eloquent cortex that can be used to guide neurosurgeons in their quest to maximize intracerebral tumour resection whilst minimizing post-procedural neurological deficits. This work aimed to develop and provide an initial assessment of such a technique. 19 patients with mass lesions close to the primary motor cortex underwent fMRI at 1.5T. A single shot echo planar technique was used to acquire data corresponding to right and left hand movement. Resultant activation maps were used to aid pre-surgical planning. Data was used in conjunction with an intraoperative navigation system in 13 cases. Activation was attributed to primary motor, primary somatosensory or supplementary motor cortex in 17 of 19 subjects. No permanent changes in motor deficit were detected post surgery. The additional information provided by fMRI, particularly when incorporated into a neuronavigation guided craniotomy, was deemed highly valuable to the neurosurgeon as it enabled safe resection of tumour in anatomical locations previously deemed to be too high risk for safe resection using conventional (non-fMRI-guided) technique. This observation is reinforced by the fact that no patients suffered permanent neurological deficit after radical tumour debulking (surgical estimates>90% tumour resection).

DOI:10.1259/bjr/66817309

出版商:British Institute of Radiology    

年代:2003

数据来源: WILEY

摘要:

Optimization of radiotherapy treatment plans based on dose–volume histograms relies on accurate organ delineation. Hollow organs, such as the rectum, are difficult and time-consuming to delineate owing to unclear visualization of the border between wall tissue and filling. Automated hollow organ delineation would be a valuable tool, but its development depends upon improved understanding of the dynamics of the rectum in response to filling. Two reasonable assumptions proposed in the literature are that (1) the rectal wall tissue along a constant length of the rectal cylinder is preserved over time and (2) the rectal wall tissue is distributed homogeneously along the cylinder. Therefore, variations in wall thickness can be explained by variable rectal filling. To investigate these assumptions, transversal cross-sectional areas enclosed by the outer contour (Aout) and inner contour (Ain) of the rectum were recorded from digital photographs of cadaver cryo-sections from the U.S. National Library of Medicine's Visible Human Project. In addition,AoutandAinwere recorded from 19 CT scans of 5 of our own patients. The transversal cross-sectional area of the wall of the rectum,Awall=Aout−Ain, was calculated. The data derived both from cryo-sections and repetitive CT scans of patients, revealed that there was a significant correlation betweenAwallandAout, in contradiction to assumption (1) stated above (male cryo-sections:p<0.001, female cryo-sections:p=0.03, repetitive CT scansp<0.001). Moreover, the meanAwallcalculated from one CT scan differed significantly from the meanAwallfrom other CT scans and was correlated with the meanAout,i.e.rectal filling (p<0.001). This finding was confirmed by careful analysis of another study (p=0.001) and opposes assumption (2). Hence, the amount of wall tissue within a constant length of rectum is not preserved over time, but increases with increased filling. This implies that the longitudinal length of the rectum decreases in response to distension of the organ.

DOI:10.1259/bjr/75640835

出版商:British Institute of Radiology    

年代:2003

数据来源: WILEY

摘要:

The present study investigated differences in the growth rate of multicellular tumour spheroids of the MCF-7 line of human breast cancer before and after their irradiation. Growth of the spheroids was analysed according to a model based on a Gompertz function. In this model, normalization to a common initial volume is achieved in a way that enables meaningful comparisons to be made between the results obtained for each spheroid. For irradiated spheroids the model includes an additional term to take account of sterilized cells. We found that the growth rate observed before irradiation is not fully recovered by irradiated spheroids and that growth recovery reduces with higher irradiation doses. Surviving fractions obtained at doses below 3 Gy are comparable with those found in clonogenic assays on spheroids of the same cellular line. At larger doses, discrepancies between the different studies are considerable.

DOI:10.1259/bjr/30772617

出版商:British Institute of Radiology    

年代:2003

数据来源: WILEY

摘要:

Sentinel node localization using an injected radiopharmaceutical and a gamma probe is performed in many hospitals. Employers have a duty to give appropriate training to staff who may not have been previously formally trained to work with unsealed radioactive sources. A study was performed to assess hazards and risks at all stages of the localization procedure. Whole body doses and finger doses of imaging, surgery and pathology staff were determined. The activity remaining in the tumour specimen, excised nodes and disposable waste from the operating theatre was measured. Any radioactive contamination of the operating theatre and equipment was also ascertained. All results were then assessed in light of current UK radiation protection legislation for the protection of staff and members of the public.Results showed that radiation doses are low and no additional procedures are required for protection of staff, provided the usual procedures for biohazards are in place. However, an information sheet has been prepared for the reassurance of staff, and theatre swabs may need to be stored temporarily before disposal. Injecting and imaging on the day before surgery is preferred, compared with injecting and imaging before surgery on the same day, since this gives lower radiation doses to staff, lower activity in excised specimens and waste, and provides a higher count rate giving better image quality.

DOI:10.1259/bjr/91805723

出版商:British Institute of Radiology    

年代:2003

数据来源: WILEY

摘要:

Dual X-ray absorptiometry (DXA) is now widely available as a method for assessing bone density. However, the place of peripheral bone densitometry in clinical practice for diagnosis of osteoporosis is not yet clear. To examine the potential use in our district general hospital setting, we compared calcaneus measurements with conventional DXA of the hip and spine in 100 patients referred for assessment following identification of risk factors for osteoporosis. Measurements were made on both heels and the results were found to be similar but not completely interchangeable. Use of receiver operating characteristic curves confirmed that a thresholdT-score of −1.6 could be used to identify many of the high risk subjects. However, there was only moderate agreement between fracture risk classifications derived from heelT-scores, and diagnostic classification (osteoporosis/osteopenia/normal) derived from axial DXA. The specificity of heel measurements was high, but sensitivity was poorer. Heel measurements could therefore be valuable in some circumstances for finding patients for whom treatment of osteoporosis would be appropriate, such as in a population with a low prevalence of osteoporosis. They may also be of value in a population with a high prevalence of disease, particularly if there were no alternative means of bone densitometry. However, with an intermediate prevalence, the relatively high risk of false negative values would mean that false reassurance could be given to many of those classed as “low risk”. This could be a major drawback in clinical practice if heel densitometry were used as the initial investigation and axial measurements were also available, since they would give conflicting results for a substantial proportion of these patients.

DOI:10.1259/bjr/56105358

出版商:British Institute of Radiology    

年代:2003

数据来源: WILEY

摘要:

The National Radiological Protection Board has recommended the introduction of dose–width product (DWP) for the measurement of patient dose in panoramic dental radiology. The present work describes a method for measuring DWP using a pencil ionization chamber. The technique was tested on five panoramic dental units; the reproducibility of the method was 5.7%. In order to test the method, DWP was also assessed using thermoluminescent dosemeters and film. The results obtained agreed within 8.6% with those obtained using the pencil ionization chamber method. The proposed method appears to be simple and precise.

DOI:10.1259/bjr/58851704

出版商:British Institute of Radiology    

年代:2003

数据来源: WILEY

摘要:

Split notochord syndrome is a spectrum of congenital spinal malformations that develops due to an adhesion between endoderm and ectoderm causing the “splitting” of notochord. Neurenteric cyst is one of the components of split notochord syndrome. We report CT and MRI findings of an unusual case with thoracal spinal cord herniation into a mediastinal neurenteric cyst.

DOI:10.1259/bjr/60547861

出版商:British Institute of Radiology    

年代:2003

数据来源: WILEY

摘要:

We present a case of pseudoaneurysm and arteriovenous fistula of the inferior epigastric artery secondary to the placement of a drain during a surgical intervention. We stress the utility of colour Doppler ultrasound and arteriography embolisation in diagnosis and treatment, respectively.

DOI:10.1259/bjr/87038703

出版商:British Institute of Radiology    

年代:2003

数据来源: WILEY