bluuebunny/crossref_metadata_2025_split huggingface dataset:
Derivation of the optimum dose per fraction from the linear quadratic model
Authors: Jones B , Tan L T , Dale R G 
Published: July 2009

Abstract
The linear quadratic equation for fractionated radiotherapy has already been adapted to include a time factor for tumour repopulation: loge cell kill (E) is given as a function of dose per fraction (d), number of fractions (n), overall treatment time (T) and the clonogen doubling time (Tp). By incorporating a normal tissue isoeffect and replacing the relationship between T and n by a function f, the equation for E can be rewritten as a more complex function of d. In this form, E and d are continuous variables so that the dose per fraction (d′) required to produce maximum values of E for isoeffective late normal tissue effects can be found by differential calculus. The derived equation takes the form and when solved for d provides a direct estimation of the optimum dose per fraction. Where normal tissue sparing is possible and the tumour dose z is related to the normal tissue dose d, the optimum dose per fraction z′ can be found by solving the equation The results show that a critical minimum dose per fraction is required to counteract rapid tumour clonogen repopulation in both conventional and accelerated radiotherapy. The calculus method is reasonably accurate for larger fraction numbers, when clonogen doubling times are 3.5 days or longer and for conventional radiotherapy given 5 days per week. The model is even more accurate for accelerated hyperfractionated radiotherapy providing that there is complete repair between successive fractions. Where greater normal tissue sparing is possible, as with focal teletherapy methods and brachytherapy, higher tumour doses per fraction can be used to increase further the tumour cell kill without exceeding normal tissue tolerance. These predicted doses per fraction are consistent with clinical experience when the given constraints in terms of frequency of treatment are considered. The model described can be used for tumours in which repopulation occurs at a constant rate throughout treatment. For tumours in which accelerated repopulation occurs, the optimum dose per fraction can be separately calculated for the initial phase of slow repopulation (for which very small doses per fraction are optimal) and also for the second phase of rapid repopulation (for which either accelerated hyperfractionated treatments or hypofractionated focal methods of treatment would be appropriate). The limitations of the model are fully discussed including the need for accurate radiobiological predictive assays. In the future such assays of pre-treatment doubling times and tumour cell radiosensitivities could be used to determine reasonable ranges for the optimum dose per fraction in experimental tumours and subsequently in clinical trials. This approach could produce major improvements in the therapeutic potential of radiotherapy.
Dual energy X-ray absorptiometry normal reference range use within the UK and the effect of different normal ranges on the assessment of bone density
Authors: Simmons A , Barrington S , O'Doherty M J , Coakley A J 
Published: July 2009

Abstract
The number of different normal ranges used on dual energy X-ray absorptiometry (DEXA) machines in the United Kingdom was determined by means of a postal questionnaire. Both femoral neck and posteroanterior spine L2–L4 regions were considered. It was clear from this survey that a variety of normal ranges were in use for all manufacturers of DEXA systems. The effects of four normal ranges supplied by Norland for use within the UK on the stratification of over 1000 consecutive patients into different grades of bone mineral density (BMD) and Z-score were examined. The main outcomes measure the number of patients with BMD less than 80% of mean age-matched BMD and Z-score less than – 1.5 over the femoral neck and spine for each normal range. The percentage of patients for each normal range with BMD less than 80% of mean for the femoral neck were 24.6%, 7.4%, 17.5% and 11.1% and for the spine 12.1%, 7.4%, 16.5% and 14.4%, respectively. For the femoral neck, 21.2%, 5.0%, 12.9% and 12.1% of patients had Z-scores of less than – 1.5, for the spine this was 7.9%, 8.1%, 14.2% and 13.6% of patients. These differences between ranges are large enough to influence patient management—patients may be diagnosed as osteoporotic using one range and normal using another. The relationship between hip and spine measurements was also studied as some therapeutic agents do not affect BMD equally at all anatomical sites. The number of patients with a lower hip than spine BMD grade varied from 12.3% to 34.4%, and with a lower hip than spine Z-score from 14.0% to 43.4%. Choice of normal range thus has a critical effect on the categorization of osteoporotic patients using DEXA. The wide variety of normal ranges indicates that there are likely to be differences in patient management throughout the country. This will be an increasing problem due to the ability of NHS purchasers to switch contracts from one provider to another.
Estimating the volume of lung irradiated during tangential breast irradiation using the central lung distance
Authors: Neal A J , Yarnold J R 
Published: July 2009

Abstract
The aim of this study was to evaluate the central lung distance (CLD) as a surrogate for the volume of lung irradiated during tangential breast radiotherapy. 20 women underwent a planning computed tomography (CT) scan and three-dimensional (3D) treatment planning for both breasts. The field size was perturbed in a systematic manner to give a number of plans with the CLD increasing from 0 to 30 mm. The volume of lung irradiated was determined directly using dose–volume histograms of the lung and correlated with the known CLD. The results indicate that absolute and percentage lung volumes increase with increasing CLD according to a quadratic relationship which is different for both left and right lungs. It is concluded that while there is no substitute for a 3D plan and a lung dose–volume histogram calculation, CLD may be used as a guide to the volume of lung included within the tangential fields used for breast radiotherapy.
Quality control of low dose craniospinal irradiation for low risk medulloblastoma
Authors: Benk V , Bouhnik H , Raquin M A , Kalifa C , Habrand J L 
Published: July 2009

Abstract
Between July 1984 and May 1990, 25 children (median age 9 years) classified as low risk medulloblastoma were treated post-operatively with low dose craniospinal irradiation (25 Gy) followed by a boost to the posterior fossa (total dose 55 Gy), with or without chemotherapy. Simulator and portal films were reviewed for all patients. Doses delivered at the mid cerebral and spinal axis, anterior vertebral body, field junctions and posterior fossa were recalculated and correlated with outcome. Three children were excluded because of inadequate data leaving 22 cases for study. The 5-year actuarial survival is 55%. Nine recurrences and one second tumour (astrocytoma) were observed. Sites of recurrence were either in the posterior fossa (5), in the brain (3), in the spinal axis (1), or combined (2). The dose delivered was within ±5% of that prescribed to the brain in 21/22 cases, and to the posterior fossa and the anterior surface of the vertebral body in 17/22 cases. The only patient who received less than 95% of the prescribed dose to the brain (23 Gy) failed in the subfrontal area and olfactory plate. One of the five patients who received less than 95% of the prescribed dose to the posterior fossa (50.3 Gy) failed at the primary site. None of the five patients who received less than 95% of the dose to the spinal axis failed. Quality control of radiation treatment showed that failures could not be correlated with incorrect technique.
Coincident granular cell tumour of the breast with invasive ductal carcinoma
Authors: Tai G , D'Costa H , Lee D , Watkins R M , Jones P 
Published: July 2009

Abstract
Granular cell tumours of the breast are rare lesions which are almost always benign. They are of interest because their clinical, radiological and pathological appearances often closely resemble those of malignancy. A case is described in which screening mammography in an asymptomatic woman led to the diagnosis of simultaneous invasive intraductal carcinoma in one breast and benign granular cell tumour in the other. Granular cell tumour of the breast coincident with other breast tumours is very rarely described and an association with breast carcinoma is unknown.
Comparison of single reading with double reading of mammograms, and change in effectiveness with experience
Authors: Warren R M L , Duffy W 
Published: July 2009

AbstractIn the prevalence round of screening for breast cancer at a single centre, the benefit of the second radiological report has been assessed using data from 33734 women, their screening results and knowledge of the interval cancers. The service was set up under the UK National Breast Screening Programme, and the data show evidence of learning by both individuals and the team as a whole. Of the 269 cancers detected by screening, 33 would not have been diagnosed if the only report available had been the first. The recall recommendation rate associated with the first report was 6.9% and 236 cancers were detected. The recall recommendation rate associated with all queries of all the reports was 10% (3354 queries). Had these 3354 queries all been investigated (instead of the 1423 actually recalled) only a further three cancers would have been detected. Sensitivity of the programme as a whole was substantially better than that of individual radiologists, while the specificity was maintained. The decision pathway by which recalls were agreed between the two radiologists resulted in a low recall rate (4.2%) for the programme as a whole, and is a critical factor in gaining the benefit of the improved sensitivity without a concomitant deterioration in the specificity. With the passage through the prevalent round, recall rates steadily fell, the malignant to benign biopsy ratio improved and sensitivity increased. The second radiological report yielded 14% additional cancers diagnosed and contributed very significantly to good sensitivity and so to the effectiveness of screening. Economic analysis of the results will be reported in a further paper.
Computed tomography manifestations of tricuspid regurgitation
Authors: Collins M A , Pidgeon J W , Fitzgerald R 
Published: July 2009

Abstract
Six patients undergoing dynamic contrast enhanced abdominal computed tomography (CT) for upper abdominal symptoms and signs are described. Each patient demonstrated early, intense opacification of the inferior vena cava (IVC) and hepatic veins, exceeding that in the aorta on scans through the upper abdomen. Opacification of the IVC returned to normal on more caudal slices. All six patients were found to have echocardiographically proven tricuspid regurgitation (TR). It is suggested that this sign occurs in patients with TR due to direct reflux of contrast from the right atrium into the IVC during protracted bolus injection. Additional CT findings included patchy parenchymal liver enhancement in four patients and ascites in five. Recognition of this simple sign may direct the clinician to a cardiac aetiology for upper abdominal symptoms and signs.
An investigation into techniques for reducing doses from neo-natal radiographic examinations
Authors: Wraith C M , Martin C J , Stockdale E J N , McDonald S , Farquhar B 
Published: July 2009

Abstract
A survey of radiation doses received by infants having radiography in a neo-natal unit was undertaken at Aberdeen Maternity Hospital. Options for dose reduction recommended by the CEC Lake Starnberg Group were investigated. Techniques were implemented for clinical evaluation after assessments of image quality with test objects and phantoms. Clinical image quality of radiographs was evaluated by paediatric radiologists using CEC criteria. Results revealed a clear relationship between entrance dose and patient weight, indicating that reference doses for infants could be linked to weight. At the start of the study the mean entrance dose for chest anteroposterior (AP) radiographs was 65 μGy and the dose-area product 12.3 mGy cm2 for a system with 2.5 mm aluminium filtration using 50 kVp X-rays with a 200 speed class film/screen system. A 400 speed class film/screen combination was investigated but not evaluated clinically, because the image quality was not considered acceptable. Addition of 0.1 mm copper to the filtration of the X-ray tube reduced entrance doses by 50%, but the technique was not adopted, because of a poorer image quality with only 72% of features in clinical images being reproduced to an acceptable standard, compared with 87% with the original system. Use of faster processing chemicals, an increase in filtration to 3.5 mm aluminium and a tube potential of 60 kVp resulted in a 40% reduction in mean entrance dose to 37 μGy with satisfactory clinical image quality.
Röntgen and the discovery of X-rays
Authors: Mould R F 
Published: July 2009

Abstract
This review celebrates the events of 100 years ago to the month of publication of this November 1995 issue of the British Journal of Radiology, when X-rays were discovered by Röntgen (8 November 1895) and he was working in his laboratory leading up to his 28 December 1895 communication “On a new kind of ray”. Biographical details of Röntgen are given, together with his work in Wörzburg before the discovery and popular and scientific opinion in the immediate months after the world first learned of the existence of X-rays. Some of Röntgen's apparatus is illustrated, accompanied by typical advertisements of 1896–1897. Where appropriate I have included information related to the UK, concerning, for example, Sir Arthur Schuster and Lord Kelvin; there is also a mention of the Röntgen Society, the forerunner of today's British Institute of Radiology.
A comparison of the methods of distraction for stress examination of the acromioclavicular joint
Authors: Sluming V A 
Published: July 2009

AbstractAcromioclavicular joint disruption is frequently evaluated with a radiographic examination of the joint under stress (weight bearing). Certain authors recommend suspending the weights from the arm, rather than being hand-held, to allow for total muscle relaxation. This study examines the relationship between the coracoclavicular distance measured and the method of distraction. 30 normal subjects participated in the study which used ultrasound (5 MHz linear array) to measure the coracoclavicular distance under four conditions (levels of traction): non-stressed, muscles relaxed; non-stressed, muscles tensed; stressed with 7.5 kg weight hand held; stressed with 7.5 kg weight suspended from the wrist.The data were subjected to a multifactor ANOVA. The level of traction was statistically significant (p&gt;0.001). The data were then subjected to a Bonferroni multiple comparisons procedure. This showed a difference between the non-stressed and stressed conditions, but there was no difference between the two methods of applying stress to the joint. It was concluded that, in normal subjects, the method of performing the weight bearing examination does not have a significant effect on the magnitude of the coracoclavicular distance.
Broadband ultrasonic attenuation: are current measurement techniques inherently inaccurate?
Authors: Petley G W , Robins P A , Aindow J D 
Published: July 2009

Abstract
Measurements of broadband ultrasonic attenuation (BUA) are currently made using large aperture, piezoelectric transducers. The use of such a receiver is known to lead to the possibility of an overestimate of ultrasonic attenuation due to phase cancellation and it is shown theoretically that this same effect can also lead to an overestimate of BUA. Using a new scanning approach, BUA was measured using two methods, one sensitive to the phase of the acoustic wave, the other not. The phase sensitive BUA measurements were found to be of significantly higher value (p &lt; 0.0001) than the phase insensitive measurements with a mean difference of 31.2 dB MHz−1. These findings are compatible with the hypothesis that BUA measurement systems with large aperture, piezo-electric receivers are inherently inaccurate.
Non-destructive elemental analysis of vertebral body trabecular bone using muonic X-rays
Authors: Hosoi Y , Watanabe Y , Sugita R , Tanaka Y , Nagamine K , Ono T , Sakamoto K 
Published: July 2009

Abstract
Non-destructive elemental analysis with muonic X-rays was performed on human vertebral bone and lumbar torso phantoms. It can provide quantitative information on all elements in small deep-seated localized volumes. The experiment was carried out using the superconducting muon channel at TRIUMF in Vancouver, Canada and a lithium drifted germanium detector with an active area of 18.5 cm2. The muon channel produced backward-decayed negative muons with wide kinetic energy range from 0.5 to 54.2 MeV. The muon beam was collimated to a diameter of 18 mm. The number of incoming muons was about 4×l06∼5×l07 per data point. In the measurements with human vertebral bones fixed with neutralized formaldehyde, the correlation coefficient between calcium content measured by muons and by atomic absorption analysis was 0.99 and the level of significance was 0.0003. In the measurements with lumbar torso phantoms, the correlation coefficient between calcium content measured by muons and by atomic absorption analysis was 0.99 and the level of significance was 0.02. The results suggest that elemental analysis in vertebral body trabecular bone using muonic X-rays closely correlates with measurements by atomic absorption analysis.
Radiographers as film readers in screening mammography: an assessment of competence under test and screening conditions
Authors: Pauli R , Hammond S , Cooke J , Ansell J 
Published: July 2009

Abstract
The aim of this study was to investigate the potential of radiographers as film readers in screening mammography. Seven radiographers received training in mammogram interpretation at a National Health Service (NHS) Breast Screening Training Centre. Film reading performance was assessed over a period of 1 year after training with test sets of selected screening mammograms. Actual screening performance on contemporary screening mammograms was monitored after training in relation to radiologist decisions and screening outcome. It was found that trained radiographers read mammograms to a standard comparable with that of radiologists. Film reading skills were maintained consistently over the period of this study and transferred to actual screening performance. It was concluded that radiographers could play a useful role as second readers in screening mammography. Training needs have to be assessed in relation to the role the film reading radiographer is to adopt.
Evaluation of 1H magnetic resonance spectroscopic imaging as a diagnostic tool for the lateralization of epileptogenic seizure foci
Authors: Constantinidis I , Malko J A , Peterman S B , Long R C , Epstein C M , Boor D , Hoffman J C , Shutter L , Weissman J D 
Published: July 2009

AbstractThe purpose of this study was to assess whether a visual examination of 1H spectroscopic images could correctly lateralize patients with intractable temporal lobe epilepsy. 20 patients with intractable temporal lobe epilepsy and 10 volunteers were included in this study. Spectroscopic images were analysed using a protocol based on visual inspection. Images of the metabolites N-acetyl aspartate (NAA), choline (Cho), creatine (Cr) and lactate were obtained from a transverse plane oriented along the sylvian fissure. Images from each individual were evaluated independently by six reviewers. Results of the lateralization procedure obtained from the visual examinations were compared with those obtained from quantitative analysis of the spectra and with those obtained by magnetic resonance imaging (MRI), positron emission tomography (PET), neuropsychological examinations, and electroencephalographic (EEG) recordings. NAA images were found to be the most effective, amongst metabolite images, in lateralizing the epileptogenic lobe. Using the site selected for resection as the definition of the correct lateralization, 70% of the patients who underwent temporal lobectomy were correctly lateralized by the majority of the examiners using the visual inspection protocol. Based on the results of this study it is concluded that visual examination of 1H spectroscopic images is potentially valid in lateralizing patients with intractable temporal lobe seizures. Confidence in the visual interpretation increased as the difference in NAA signal intensity between the temporal lobes increased. The threshold above which the majority of the examiners correctly lateralized the patients was ≈15% in NAA signal loss in the ipsilateral lobe.
Clinically suspected scaphoid fracture: a comparison of magnetic resonance imaging and bone scintigraphy
Authors: Thorpe A P , Murray A D , Smith F W , Ferguson J 
Published: July 2009

Abstract
59 patients with clinical suspicion of scaphoid fracture, but negative radiographs at presentation and review, were examined by magnetic resonance imaging (MRI) and bone scintigraphy (BS). The diagnoses were compared with subsequent follow-up. There were four scaphoid fractures, 10 other fractures and three significant ligamentous injuries. All scaphoid fractures were identified by MRI and BS. MRI showed better interobserver agreement for scaphoid injury than BS and fewer false positive reports. Significant ligamentous injury and carpal instability diagnosed by MRI were not evident on scintigraphy. Using fast scanning protocols the cost of MRI is comparable with that of BS. MRI should be considered as the appropriate second line investigation in these clinical circumstances.
Ganglioneuroma: computed tomography and magnetic resonance features
Authors: Ichikawa T , Ohtomo K , Araki T , Fujimoto H , Nemoto K , Nanbu A , Onoue M , Aoki K 
Published: July 2009

Abstract
12 patients who had histological proven ganglioneuromas were investigated by computed tomography (CT) and magnetic resonance (MR) imaging. CT scans (n = 11), conventional spin-echo MR images (n = 10) and dynamic MR images (n = 5) were acquired. All lesions showed a well defined, oval shape. Five lesions (42%) showed calcification which was punctate in four and coarse in one on CT. CT attenuation was predominantly low in three of 10 (30%) and intermediate in the remaining seven (70%). In all lesions MR signals were mainly of low intensity on T1 weighted images (T 1WI) and of high intensity on T2 weighted images (T 2WI). Dynamic MR studies in five cases showed a lack of early enhancement but gradual increasing enhancement One case had a ganglioneuroblastoma component which showed soft-tissue density and coarse calcifications on CT scans, MR images with intermediate intensity on T 1WI and T 2WI and early enhancement and little washout on dynamic MR images. In conclusion, ganglioneuroma typically shows punctate calcification and low attenuation on CT and marked hypenntensity on T 2WI with gradual increasing enhancement on dynamic MR images If a ganglioneuroma has atypical CT and MR features, coexistence of a malignant component should be considered.