bluuebunny/crossref_metadata_2025_split huggingface dataset:
The determination of total filtration on mammographic X-ray sets
Authors: Robson K. J. , Kotre C. J. , Faulkner K. 
Published: July 2009

Abstract
Data produced by a computer model are presented which allow the amount of molybdenum filtration on a molybdenum target mammographic X-ray set to be estimated from the measurement of the half value layer (HVL) in aluminium. Existing data refer either to tungsten target tubes or to molybdenum target tubes for a single anode angle and a constant potential waveform with the compression plate present. In addition to the tube voltage, the present data take account of the waveform of the tube potential and target angle. The results of an experimental verification of the model are presented and the effect of the geometry used in the experimental set-up discussed. Theoretical predictions of the molybdenum filter thickness made using the data from the model are in good agreement with the measured filter thickness, provided that attention is paid to the experimental geometry.
A comparison of four mammographic image quality test objects
Authors: Payne M. , Lawinski C. P. 
Published: July 2009

The need for rigorous image quality assurance in mammography is well documented (Pritchard Report, 1989). However, there is still debate over the suitability of those image quality test objects commercially available. We have been able to compare three contemporary test objects with the “Barts” test object which has been in use since 1980 and has been used as a standard by many workers (Kirkpatrick & Law, 1987). The four mammographic test objects have been compared using six mammographic film-screen combinations. The following test objects were used.
The “Barts” mammographic image quality test object (White & Tucker, 1980). This object contains several series of opacities designed to mimic mammographic diagnostic features, some being fat equivalent, some water equivalent, some skin equivalent and some equivalent to calcifications, which are immersed in an epoxyresin scattering medium. The object is designed to assess contrast and resolution combined in various ways.
The Dupont mammographic image quality test object (Ackermann, personal communication, 1988). This simulates microcalcifications, fibrous structures and small spherical objects. It also allows an assessment of minimal detail contrast, line resolution in two dimensions and point resolution. A selection of organic materials is included to simulate benign and malignant tumours, lymph nodes and tissues characteristic of a dense breast. It is designed to be used with a stack of attenuator plates to provide the appropriate absorption, scatter and geometrical unsharpness in test exposures.
Improved image quality for dense breasts in mammography
Authors: Law J. 
Published: July 2009

Please note that the films reproduced in parts (a) and (b) of Fig. 2 (p. 51) should be interchanged to correspond with the caption and the text.
Thus the lighter film was obtained with the normal exposure (28 kV, 63 mAs), and the darker film was obtained with the increased exposure (28 keV, 120 mAs).
The Publisher apologises to both the author and the readers for this error.
Reference
LAW, J., 1992. Improved image quality for dense breasts in mammography. British Journal of Radiology, 65, 50–55.
The role of 3D CT in the assessment of acetabular fractures
Authors: Guy R. L. , Butler-Manuel P. A. , Holder P. , Brueton R. N. 
Published: July 2009

Abstract
A total of 16 patients with acetabular fractures were evaluated by plain radiography, axial computed tomography (CT) and three dimensional (3D) CT. It was possible to classify the fracture type in each case from the plain radiographs alone. Axial CT gave additional detail in certain areas, notably the region of the teardrop, the obturator foramen and the acetabular roof. Intra-articular and impacted roof fragments and associated soft tissue injuries were also shown. 3D CT provided the best and most easily interpreted overall assessment of the fractures. In addition to projections equivalent to the plain radiographs, two other views were of particular clinical value in demonstrating surgically inaccessible areas, namely the view of the pelvis from above and the view of the inner aspect of the fractured hemipelvis. However, fracture lines demonstrated on plain radiographs and axial CT were not always apparent on the 3D CT scans. Although 3D CT is a valuable addition to the imaging of acetabular fractures, it is not a substitute for good quality plain radiography and analysis of the axial CT images.
Computed tomography in abdominal trauma: an audit of usage and image quality
Authors: Padhani Anwar R. , Watson Christopher J. E. , Clements Leigh , Calne Roy Y. , Dixon Adrian K. 
Published: July 2009

Abstract
The use and quality of computed tomography (CT) in the evaluation of blunt abdominal trauma has been assessed by a retrospective review of 122 patients referred in the first 8 years following the installation of CT of the body. The referral patterns were analysed, and the quality of the images was assessed, with particular reference to unsatisfactory (unacceptable or poor) images. Referrals increased over the 8 years following installation. A large proportion of these examinations were performed outside normal working hours (58/122, 48%). In 64 out of 122 (52%) of examinations the images were considered of unsatisfactory quality with inadequate use of intravenous contrast medium cited as the most common cause for unsatisfactory exminations. Image quality did not improve with time. Image quality was unsatisfactory in a larger proportion of those examinations performed outside normal working hours (35/58, 60%) than those during the routine working day (29/64, 45%), although this difference did not reach statistical significance (0.1 &gt; p &gt; 0.05). Fewer unsatisfactory examinations were produced by a system dedicated to body CT (31/74, 42%) than by a neuroradiological system (33/48, 69%) (p &lt; 0.01). The proportion of unsatisfactory abdominal examinations was lower when the CT study concentrated on the abdomen (26/65, 40%) than when multiple regions (head, chest, abdomen, etc.) were examined (38/57, 67%) (p &lt; 0.01). This audit revealed many unsatisfactory examinations. In order to complete the audit loop we have addressed many of the contributory factors. A new CT system now provides images of high quality and is used for all abdominal work. Guidelines, which describe an optimized technique, have been issued to radiographers and radiologists. In particular, we have emphasized that there is no place for a poorly supervised “quick look” at the abdomen following a cranial or thoracic study.
Quantitative analysis of CT brain images: a statistical model incorporating partial volume and beam hardening effects
Authors: McLoughlin Raymond F. , Ryan M. Veronica , Heuston Paula M. , McCoy Catherine T. , Masterson James B. 
Published: July 2009

Abstract
The purpose of this study was to construct and evaluate a statistical model for the quantitative analysis of computed tomographic brain images. Data were derived from standard sections in 34 normal studies. A model representing the intracranial pure tissue and partial volume areas, with allowance for beam hardening, was developed. The average percentage error in estimation of areas, derived from phantom tests using the model, was 28.47%. We conclude that our model is not sufficiently accurate to be of clinical use, even though allowance was made for partial volume and beam hardening effects.
The musculoskeletal manifestations of epidermolysis bullosa: an analysis of 19 cases with a review of the literature
Authors: Wong Wai Lup , Pemberton James 
Published: July 2009

Abstract
Epidermolysis bullosa encompasses a group of rare disorders characterized by marked skin fragility and blister formation. In patients with dystrophic epidermolysis bullosa, skeletal and soft-tissue abnormalities are an important feature. An analysis of the musculoskeletal manifestations in 19 patients is presented. In the hands and feet, features included generalized osteoporosis, wedge-shaped thinning and hooking of distal phalanges, overconstricted bones, acro-osteolysis, flexion contractures, metatarsal and metacarpal subluxation, distal trophic changes, webbing of digits, encasement of the whole extremity in a pouch of skin, soft-tissue calcification and retarded skeletal maturity. Previously undescribed findings in the hands and feet are bony ankylosis of the proximal interphalangeal joints, resorption of the metatarsal and metacarpal heads, shortened metatarsal bones, carpal and tarsal fusion and destruction, and cystic changes of the distal radius and ulna. In the remainder of the skeleton, hip dysplasia with premature osteoarthritis, knee joint bony ankylosis and thoracic and thoraco-lumbar scoliosis are other undescribed findings.
Magnetic resonance imaging of pulsatile cerebrospinal fluid flow by spatial modulation of magnetization
Authors: Wayte S. C. , Redpath T. W. , Beale D. J. 
Published: July 2009

Abstract
Various orders of binomial spatial modulation of magnetization sequences up to (1 4 6 4 1) have been tested to find the optimum sequence for clinical application. Stripe width, stripe sharpness and the tolerance of the sequences to radiofrequency non-linearity have been investigated. The (1 3 3 1) sequence was found to be a good compromise between competing design criteria, and its application to viewing pulsatile cerebrospinal fluid motion is described.
The value of magnetic resonance relaxation time in staging ovarian endometrial cysts
Authors: Sugimura Kazuro , Takemori Masayuki , Sugiura Makiko , Okizuka Hiromi , Kono Michio , Ishida Tetsuya 
Published: July 2009

Abstract
We evaluated the use of magnetic resonance imaging (MRI) in the pre-operative staging of 15 endometrial cysts. The effect of the iron content on the T 1 and T 2 relaxation times was assessed in confirmed endometrial cysts employing a 0.15 T MR system and a 200 MHz spectrometer. There was a positive linear correlation (r = 0.93) between the T 1 values of the lesions obtained using the MR system (T 1) and those of the resected cyst contents obtained using the spectrometer (sp-T 1). A similar relationship was found between T 2 and sp-T 2(r = 0.87). There was a negative linear relationship between the T 1, value and the cyst iron content (r = –0.81), but there was no relationship between the T 2 value and the iron content. T 1 was 412±91 ms for Stage II cysts (n = 3), 356±126 ms for Stage III cysts (n = 3) and 208±30 ms for Stage IV cysts (n = 9). The T 1 value for Stage IV cysts was significantly shorter than that for Stages II and III cysts (p&lt;0.05). Thus, the T 1 value was useful in distinguishing fresh from old endometrial cysts, suggesting that the MRI T 1, relaxation time might be useful for staging ovarian endometrial cysts before surgery.
Audit in action: significant reduction of double-contrast barium enema screening time with no loss of examination quality
Authors: Horton D. , Cook A. M. , Taylor A. D. 
Published: July 2009

Abstract
The double-contrast barium enema is an examination of high radiation exposure to the patient. As part of a departmental audit, our own fluoroscopic screening times were being recorded. A study was undertaken to see if a determined effort could reduce the screening time without having a detrimental effect on the quality of the examinations. Methods of screening time reduction were identified and then implemented by two radiologists. In the period before the study the average screening time for radiologists A and B was 2.6 min and 3.2 min, respectively (over 56 examinations). After implementation of the changes, the average screening time for both was 0.9 min (over 50 examinations). This is a statistically significant reduction (p &lt; 0.01). The examinations were assessed independently by a gastroradiologist. No difference in the quality of the examinations was identified. We conclude that a significant reduction of screening time for the double-contrast barium enema can be achieved without loss of examination quality.
Output factors for blocked fields
Authors: Dean E. M. , Davis J. B. 
Published: July 2009

Abstract
This study investigates the output from blocked treatment fields with 6 MV and 18 MV photons. Square fields, defined collimators, were blocked down to smaller symmetrical square, rectangular and asymmetrical rectangular fields using blocks on tray beneath the collimators. Up to 7.5% difference was found between the output measured for the blocked field and the output calculated using a collimator output factor for the surface field size. A method is described by which output factors for the blocked fields can be measured and used in practice. Three methods of approximating these output factors are also presented.
The application of microdosimetry in clinical bone densitometry using a dual-photon absorptiometer
Authors: Waker A. J. , Oldroyd B. , Marco M. 
Published: July 2009

Abstract
Experimental microdosimetric methods have been used to determine absorbed dose values for a scanning dual-photon absorptiometer. Absorbed doses within the scanned field have been obtained for three different scanning speeds. For the normal speed setting used clinically, measurements have also been carried out in a water-filled phantom in order to estimate typical patient entrance, exit and midline doses. The results agree well with values obtained using thermoluminescence dosimetry and support the claims of the manufacturers with regard to upper limits placed on patient dose levels. The microdosimetric method enables changes in radiation quality to be followed and comparisons to be made with other low-energy photon fields used in medical diagnosis.
A preliminary investigation of the imaging performance of photostimulable phosphor computed radiography using a new design of mammographic quality control test object
Authors: Cowen A. R. , Brettle D. S. , Coleman N. J. , Parkin G. J. S. 
Published: July 2009

Abstract
Leeds Test Object TOR[MAM] has been designed to supplement the current FAXIL mammography test object TOR[MAX]. It contains a range of details that have a more natural radiographic appearance and has been designed as a test that more closely approximates the image quality achieved in clinical mammography. Physical aspects of the design and implementation of TOR[MAM] are presented. The TOR[MAM] has been used in a preliminary physical evaluation of the comparative image qualities produced by conventional (screen–film) and photostimulable phosphor computed mammography and the results are discussed. TOR[MAX] results are also presented. The influence of digital image processing (enhancement) on the image quality of computed mammograms is also considered. The results presented indicate the sensitivity of TOR[MAM].
Technique for steel coil embolization of biopsy track for use with the “Biopty” needle
Authors: Dawson Peter , Adam Andreas , Edwards Richard 
Published: July 2009

Percutaneous biopsy is quick, usually relatively easy to perform with a minimum of special equipment and, with its high diagnostic yield and low associated morbidity and mortality, is a key tool in the radiologist's armamentarium. Indeed, it is the single most frequently performed interventional procedure. A number of risks have been enumerated (Perrault et al, 1978; Westaby, 1980; Reichert et al, 1983; Whitmire et al, 1985; Lees, 1987), the most serious being severe bleeding, particularly, but not exclusively, in patients with a bleeding diathesis. The bleeding is thought to be related to needle size, and fine-needle aspiration cytology (FNAC), which, with improvements in cytology, is a reliable procedure (Lees et al, 1985), is thought to be safer than histological biopsy. However, there are frequently circumstances, such as diffuse organ disease, suspected unusual or benign neoplasms and lymphoma, where a core biopsy using a larger cutting needle is desirable in spite of some increased risk.
For liver biopsy, in particular, a number of alternative techniques to the percutaneous approach have been developed, the transjugular approach being the most favoured (Hanafee & Winer, 1967; Korshin et al, 1978; Bull et al, 1983; Colapinto, 1985).
Radiation protection associated with well women breast cancer screening
Authors: Moores B. M. , Henshaw E. T. 
Published: July 2009

We wish to raise a number of issues concerning radiation protection aspects associated with well women breast cancer screening programmes now established throughout the UK.
Does irradiation of well women for screening purposes constitute a medical exposure and, therefore, fall within the terms of the 1988 Ionizing Radiation (Protection of Persons Undergoing Medical Examination or Treatment) Regulations? If so, then according to section 4 part 3, persons physically directing a medical exposure shall select procedures such as to ensure a dose of ionizing radiation to the “patient” as low as reasonably parcticable in order to achieve the required diagnostic or therapeutic purpose.
Two cases of isolated deficiency of all four limbs diagnosed antenatally with a review of the literature
Authors: Wong W. L. , Clarke O. , Bhattacharya J. , MacDonald L. M. 
Published: July 2009

Congenital absence of a limb (amelia) is extremely rare with an incidence ranging from between 0.05 to 0.15 per 10000 live births with total absence of an upper limb having an incidence of between 0.02 to 0.07 per 10000 live births (Birch-Jensen, 1949; Bod et al, 1983; Froster-Iskenius & Baird, 1990; Kallen et al, 1984). The different rates quoted probably reflect the different periods over which the cases were collected in the various studies, ranging from 3 to 32 years, rather than a true variation.
Complete absence of all four limbs is particularly unusual. Froster-Iskenius and Baird identified two cases amongst 1213913 consecutive live births in British Columbia between 1952 and 1984, one of which was associated with thalidomide exposure (Froster-Iskenius & Baird, 1990). In their search of the world literature, Dresher and MacDonell identified only 11 cases, including one described in 1886. To these they added a further two cases (Dresher & MacDonell, 1965).
We present two cases of severe limb reduction diagnosed by ultrasound scanning during the second trimester. In one case all four limbs were absent and in the other one limb was absent and there was severe reduction of the other three.
A 37 year old Indian (G7, P6) presented for a routine ultrasound examination at 19 weeks. She had no family history of congenital abnormalities. There were no complications to the pregnancy at this time.
A single live fetus of 19½ weeks gestation was demonstrated. All intracranial and intra-abdominal structures were normal and correctly sited.
Prenatal ultrasonographic diagnosis of an aneurysm of the vein of Galen
Authors: Worswick L. , Lamont R. F. , Thomas R. , Gordon H. 
Published: July 2009

A 31-year-old white woman, gravida 2, para 1 was admitted to hospital because of pre-term labour at 29 weeks gestation. An ultrasound scan at 18 weeks gestation at the referring hospital had shown normal fetal anatomy.
On admission, an ultrasound scan revealed a midline, fusiform, echo-free area measuring 35 mm × 20 mm × 20 mm in the fetal brain, superior to the thalamus and extending posteriorly (Fig. 1). The remainder of the fetal anatomy was normal, except for mild left-sided renal pelvic dilatation. There were no signs of fetal hydrops or ascites. An aneurysm of the vein of Galen (AVG) was suspected and Doppler studies were performed which revealed arterial type flow within the cystic structure (Fig. 2).
Subluxation of the patella: evaluation of patellar articular cartilage with MR imaging
Authors: Nakanishi Katsuyuki , Inoue Masahiro , Harada Koushi , Ikezoe Junpei , Murakami Takamichi , Nakamura Hironobu , Kozuka Takahiro 
Published: July 2009

Abstract
In patients with subluxation of the patella, injury of the patellar articular cartilage is frequently observed, and correct evaluation of this cartilage injury is extremely important for the management of these patients. Magnetic Resonance (MR) studies were performed on 102 patellofemoral (PF) joints of 51 patients with subluxation of the patella and 20 PF joints of 10 healthy volunteers. In 77 of the 102 PF joints with subluxation, arthroscopy and/or operation were performed. MR images were obtained with spin-echo and FLASH sequences, and para-axial images were obtained. We retrospectively analysed the MR findings of the 77 joints with special attention to the surface and thickness of the cartilage, and classified them into four grades. These MR grades were compared with the grades on arthroscopy, and the following results were obtained: MR grade 0, normal cartilage (n = 27, sensitivity 90.9%, specificity 74.2%); MR grade 1, thickening of the cartilage (n = 24, sensitivity 50%, specificity 89.1%); MR grade 2, surface irregularity of the cartilage (n = 20, sensitivity 85%, specificity 94.7%); MR grade 3, loss of the cartilage (n = 6, sensitivity 100%, specificity 100%). Although the early changes observed by arthroscopy were underestimated from the MR images, MR imaging proved to be extremely useful for evaluating moderately or advanced patellar cartilage injury.
Accelerated fast neutron therapy: a pilot study
Authors: Husband D. J. , Errington R. D. , Myint Sun , Littler J. A. H. , Warenius H. M. 
Published: July 2009

Abstract
The clinical role of fast neutron therapy has been limited by excessive late normal tissue damage. A pilot study of accelerated fractionation of fast neutron therapy was performed, based on the rationale that this should result in an increase in the response in acute reacting tissues (normal and malignant), with no change in late damage and a consequent increase in the therapeutic ratio. Further accelerated fractionation should improve the local control of rapidly proliferating tumour, without the potential problem of inadequate reoxygenation inherent in accelerated photon schedules. 6 or 12 fractions of 62 MeV (p-Be) neutrons were given over 12 days to 27 sites in 23 patients with locally advanced tumours. With a dose reduction of 12% (18 Gy), acceptable skin and oral mucosa early reactions were obtained. A larger dose reduction (15%) was required at pelvic sites. The incidence of late EORTC/RTOG grade 4 toxicity was 46%. The overall response rate was 76% with a complete response rate of 16%. For locally advanced breast cancer, the complete response rate was 9%, which compares unfavourably with previous results with conventional neutron fractionation schedules. The combination of a low overall complete response rate and excessive late normal tissue toxicity suggests that accelerated fractionation of fast neutrons does not lead to an improvement in the therapeutic ratio, and that late normal tissue damage will continue to be dose limiting.