bluuebunny/crossref_metadata_2025_split huggingface dataset:
Myocardial velocity gradients detected by Doppler imaging
Authors: Fleming A D , Xia X , McDicken W N , Sutherland G R , Fenn L 
Published: July 2009

Abstract
Using a scanner whose colour Doppler mode has been adapted to display tissue motion (instead of blood flow), velocity gradients have been detected across the myocardium. A velocity gradient is a gradual spatial change in the value of velocity estimates. Velocity gradients have potential for assessing regional myocardial contractility. 28 M-mode scans were performed on nine normal volunteers at different locations in the leftventricle posterior wall. In each case simultaneous Doppler M-mode and pulse-echo M-mode images were obtained. Doppler velocity gradient (DVG) was calculated from Doppler M-mode images and rate of change of wall thickness (RCWT) was calculated from pulse-echo M-mode images. In all Doppler M-mode images statistically significant velocity gradients were observed. In all but one scan, cyclically consistent peaks in DVG occur relative to the electrocardiogram waveform. 99% of systolic and 89% of early diastolic peaks in RCWT have a corresponding peak in DVG. Velocity gradients are consistent with wall thickness changes, suggesting that they have potential for assessment of myocardial contractility.
Aortic distensibility in post-menopausal women receiving Tibolone
Authors: Lehmann E D , Hopkins K D , Parker J R , Turay R C , Rymer J , Fogelman I , Gosling R G 
Published: July 2009

Abstract
Both oestrogen and androgens have been shown to affect the structural composition and biophysical properties of the arterial wall in vitro. A non-invasive Doppler ultrasound technique, based on the measurement of pulse wave velocity along the thoraco-abdominal aortic pathway, was used to assess aortic compliance C in vivo in 49 normotensive, normal, healthy post-menopausal female subjects. 23 of the women had been receiving Tibolone, a synthetic steroid structurally related to norethisterone, for at least 3 years. Since C varies with non-chronic changes in blood pressure, an index of intrinsic aortic distensibility, Cp, normally independent of blood pressure, was also calculated. No significant difference was found between the control group and those subjects receiving Tibolone for age, body mass index, systolic blood pressure, diastolic blood pressure, C or Cp. As one would expect the control group Cp values did not show a significant relationship with blood pressure (r = −0.1, not significant). However, in the Tibolone group some dependence of Cp values on pressure still remained (r = −0.58, p &lt; 0.004), suggesting that oral administration of Tibolone had altered the dynamic relationship between structural and functional biophysical properties of the aortic wall in vivo.
The admission chest radiograph after acute inhalation injury and burns
Authors: Wittram C , Kenny J B 
Published: July 2009

Abstract
The admission chest radiographs of 29 patients admitted with acute inhalation injury and burns, who required ventilatory support, were analysed for signs of inhalation injury. Four were excluded because of a history of chronic bronchitis or cardiac failure. 13 had radiological signs of inhalation injury, which included oedema of a nodular, consolidatory and interstitial pattern, and linear opacities due to atelectasis. 12 chest radiographs were normal. Inhalation injury in burns cases often requires clinical, bronchoscopic and blood gas assessment. Although changes were noted on 13/25 chest radiographs, the admission chest radiograph is an insensitive indicator of airway and parenchymal lung damage following acute inhalation injury and burns. We draw attention to the fact that significant lung damage may be present even with a normal initial chest radiograph.
Calculation of dose conversion factors for posterior–anterior chest radiography of adults with a relatively high-energy X-ray spectrum
Authors: Schultz F W , Geleijns J , Zoetelief J 
Published: July 2009

AbstractIn a survey of X-ray units as applied for thorax examinations considerable variations were observed in entrance dose among different hospitals in the Leyden region. For the median exposure conditions, i.e. 125 kVp, heavy filtering and large focus-to-skin distance (177.5 cm), absorbed dose distributions have been derived using mathematical phantoms of a standard male or female adult. For relatively high-energy X-rays, back scatter factors were calculated by Monte Carlo simulation. In addition, conversion factors were obtained, relating organ doses to air kerma, free in air. Effective dose equivalent and effective dose were calculated according to ICRP-26 and ICRP-60 recommendations, respectively. The computational procedures were compared with results reported in the literature for a similar exposure configuration but using lower-energy X-rays. Causes of relative differences ranging from – 56% to + 34% were analysed. In addition to the photon energy spectrum and filtering, the exposure geometry appears to be a very important parameter which can be optimized for the purpose of dose reduction.
The depth-dependent radiation response of human melanoma cells exposed to 65 MeV protons
Authors: Courdi A , Brassart N , Hérault J , Chauvel P 
Published: July 2009

Abstract
Radiation therapy with positively charged particles implies that the Bragg peak be spread out to deliver a homogeneous dose to the tumour. The spread-out Bragg peak (SOBP) has a higher linear energy transfer (LET) than the entrance beam. In addition, there is an LET gradient from proximal to distal SOBP. The aim of this study is to find out whether these small LET variations lead to differences in radiation response. Human melanoma cells (CAL4) were exposed to 65 MeV proton beams produced by the cyclotron Medicyc at five different positions: 2 mm depth corresponding to the entrance, 15, 20, 25 and 26.8 mm depth corresponding to four different positions in the half-modulated SOBP. Survival curves were generated using the in vitro colony method and fitted with the linear-quadratic model. Survival differences were observed at high doses; they were statistically significant at a dose of 8 Gy. With respect to the entrance position (2 mm), the relative biological effectiveness (RBE) at 1% survival was 1.09, 1.12, 1.19 and 1.27 at 15, 20, 25 and 26.8 mm in the SOBP, respectively. Whereas RBE values in the SOBP greater than 1.0 relative to the entrance beam represent a small biological advantage to be added to the well-known physical advantage of high energy proton beams; the RBE gradient along the SOBP would imply that the distal end of the tumour would receive a higher biologically equivalent dose than the proximal end, despite a homogeneous physical dose, especially at the high doses per fraction given in ocular melanomas. Although the increase in effectiveness with depth is mild, it should be kept in mind during eye treatment planning, in case a critical target is present at the extreme end of the SOBP.
Reproducibility of bone ages when performed by radiology registrars: an audit of Tanner and Whitehouse II versus Greulich and Pyle methods
Authors: King D G , Steventon D M , O'Sullivan M P , Cook A M , Hornsby V P L , Jefferson I G , King P R 
Published: July 2009

Abstract
This audit analysed the Tanner and Whitehouse II twenty bone (TW2) method of bone age assessment which was used in our department, and compared it with the Greulich and Pyle (GP) method. 50 previous bone ages were independently re-calculated by each of three registrars using both techniques, with the time taken to perform each assessment being recorded. For each method the interobserver variation was analysed in terms of the spread of results. The intraobserver variation in TW2 was determined by comparing the bone age originally reported with that subsequently calculated on the same film by the same registrar. The average spread of results was 0.74 years for TW2 method, and 0.96 years for the GP method and this difference is not statistically significant at the 5% level. The average intraobserver variation to TW2 was 0.33 years, but with 95% confidence limits of −0.87 to +1.53 years. The average time taken was 7.9 min for TW2 and 1.4 min for GP assessments. It was concluded that the GP method gave similar reproducibility and was faster than the TW2 method. Following clinical discussion the routine departmental bone age assessment method was changed from the TW2 to the GP method.
A comparative study of peri-prosthetic bone mineral density measurement using two different dual-energy X-ray absorptiometry systems
Authors: Cohen B , Rushton N 
Published: July 2009

Abstract
24 patients aged 38–72 years with an uncemented total hip arthroplasty had dual-energy X-ray absorptiometry of the upper femur performed at a mean of 27 months after surgery. Each patient was scanned on both Lunar DPX and Hologic QDR-1000 densitometers. Peri-prosthetic bone mineral density (BMD) around the femoral component was measured in seven Gruen zones using software analysis techniques to allow quantification of bone mineral adjacent to a metal implant. There was a high correlation between the results obtained with the two systems (r = 0.94). BMD measurements using the Lunar DPX were 11% higher than with the Hologic QDR; however, there was a lack of agreement between the two instruments indicating that the two methods may not be used interchangeably.
Perinephric-splenic fistula—a complication of percutaneous perinephric abscess drainage
Authors: Stewart I E T , Borland C 
Published: July 2009

AbstractA case of acute perinephric abscess due to chronic parenchymal disease and calculi is presented. During percutaneous drainage a reno–splenic vein communication developed acutely. The aetiology and treatment complications of perinephric abscesses are reviewed.
Colonic stricture and fibrosis associated with high-strength pancreatic enzymes in a child with cystic fibrosis
Authors: McHugh K , Thomson A , TAM P 
Published: July 2009

Abstract
High-strength pancreatic enzymes have recently been implicated as a cause of colonic strictures in children with cystic fibrosis (CF). We report a 5-year-old boy with CF who had a stricture of the hepati flexure region with associated narrowing due to submucosal fibrosis of the transverse colon, secondary to high-lipase pancreatin therapy.
Perinephric angiomyolipomas in tuberous sclerosis
Authors: Peh W C G , Lim B H , Tam P C 
Published: July 2009

Abstract
Bilateral large perinephric angiomyolipomas in a young Chinese woman with tuberous sclerosis are reported. Computed tomography (CT) demonstrated large fatty masses, containing abnormally dilated blood vessels and muscle strands, within the Gerota's fascia bilaterally. There were multiple foci of involvement in both kidneys. The diagnosis was confirmed on histological examination of the excised left perinephric angiomyolipoma and nephrectomy specimens. The patient subsequently developed bilateral pneumothoraces which were surgically treated. High resolution CT showed extensive thin-walled cysts in both lungs.
European Society of Mastology Consensus Conference on Breast Cancer Screening: Report of the Evaluation Committee
Authors: Wald N J , Chamberlain J , Hackshaw A 
Published: July 2009

Abstract
On 4 February 1993, the European Society of Mastology (EUSOMA) convened a meeting of experts in Paris to evaluate the current evidence on the value and hazards of breast cancer screening. The Committee consisted of individuals from different countries throughout Europe and from different disciplines. We summarise here the deliberations and conclusions of the Committee.
The persistent computed tomography nephrogram: its significance in the diagnosis of contrast-associated nephrotoxicity
Authors: Love L , Johnson M S , Bresler M E , Nelson J E , Olson M C , Flisak M E 
Published: July 2009

Abstract
A study was undertaken to find out if there is a quantitative relationship between the development of contrast-associated nephrotoxicity (CAN) and the mean renal cortical attenuation (RCA) as seen on computed tomography (CT) examination of the kidneys 24 hours after injection of contrast medium. 96 patients undergoing aortography were selected, who were considered “high risk” either because of the presence of a baseline serum creatinine (Cr) of 123.76 μmol I-1 (1.4 mg dl-1) or higher, or who were 73 or older with or without elevated creatinine levels. A CT study of the kidneys at approximately 24 h was correlated with baseline serum creatinine as well as 24 h Cr (48–72 h Cr when available). Medical history and medications were recorded. Eight of 96 patients had RCA of 108–236 HU at 24 h CT and all developed significant CAN of varying degree; 3/96 had RCA ranging from 48 to 67 HU and had transient CAN; two other patients with RCA of 67–90 HU developed CAN; and there was increased incidence of CAN in patients: (a) with pre-existing renal insufficiency; (b) with diabetes with renal insufficiency; (c) on diuretics; (d) who were older; and (e) had a unilateral atrophic kidney. It was concluded that a 24 h CT study evaluating the RCA had better predictive value for the development of CAN than a 24 h creatinine level.
Iomeprol versus iopromide for intravenous urography
Authors: de Geeter P , Melchior H 
Published: July 2009

Abstract
Iomeprol (B16880) is a new non-ionic tri-iodinated radiographic contrast medium. It was the aim of this double blind randomized phase III clinical trial to compare the local and systemic tolerance of iomeprol-300 (300 mg I ml-1) with the commercially available iopromide-300 (300 mg I ml-1) in a group of 198 patients needing intravenous urography. The contrast medium was injected rapidly into an antecubital vein within 2–3 min in most cases, using a standard dosage of 1 ml kg-1 body weight. The proportion of patients with an allergic diathesis was 25% in the iomeprol group and 17.3% in the iopromide group. There were no life-threatening adverse reactions. Eight patients (8%) receiving iomeprol and 6 (6.1%) receiving iopromide had a sensation of heat related to the injection of contrast medium. Only one patient (1%) in the iomeprol group and two patients (2%) in the iopromide group noted pain on injection. Although the incidence of all other side-effects was relatively high (7% after iomeprol and 11.2% after iopromide) these reactions were generally harmless. The most common symptom was nausea and/or vomiting, which occurred with the same incidence (5%) in both groups. Only one patient in each group developed urticaria or erythema. Vital parameters remained essentially unchanged in all patients. The results suggest that iomeprol is a safe contrast medium, with a tendency to produce fewer side effects than iopromide, which is known to be particularly well tolerated.
The relationship between bone mineral density, vertebral body shape and spinal curvature in the elderly thoracolumbar spine: an in vitro study
Authors: Edmondston S J , Singer K P , Price R I , Day R E , Breidahl P D 
Published: July 2009

Abstract
Vertebral body geometry, defined by the anterior/posterior (A/P) and mid/posterior (M/P) vertebral body height ratios, was measured in 18 vertebral columns (T1–L5) from sagittal computed tomography scans. For each vertebra, the trabecular density (VTD) and bone mineral density (BMD) were measured using quantitative computed tomography (QCT) and dual-energy X-ray absorptiometry (DXA), respectively. Lateral view radiographs were digitized to measure the thoracic curvature. The segmental correlations between vertebral shape and bone density were poor (r = 0.01–0.31). The mean thoracic BMD and VTD and the mean lumbar VTD were significantly correlated with the mean thoracic A/P ratio (r = 0.55–0.69). The thoracic curvature was significantly correlated with both the mean thoracic and the mean lumbar VTD and BMD (r = 0.55–0.73). In summary, the extent of vertebral wedging and thoracic curvature was moderately indicative of the mean BMD of the thoracic vertebrae, and lumbar spine densitometry is useful to assess the relative severity of osteopenia in individuals with thoracic vertebral deformities.
The effects of static 3.0 T and 0.5 T magnetic fields and the echo-planar imaging experiment at 0.5 T on E. coli
Authors: Mahdi A , Gowland P A , Mansfield P , Coupland R E , Lloyd R G 
Published: July 2009

Abstract
Various mutant strains of Escherichia coli have been exposed to a homogeneous static magnetic field of either 0.5 T or 3.0 T and to the time varying magnetic fields found in echo-planar imaging experiments. No evidence of increased DNA damage was detected, even with bacterial strains disabled for DNA repair.
Hepatic ultrasound findings in the glycogen storage diseases
Authors: Lee P , Mather S , Owens C , Leonard J , Dicks-Mireaux C 
Published: July 2009

Abstract
Hepatic ultrasonography was performed on 70 patients with the hepatic glycogen storage diseases (GSDs) to assess parenchymal echogenicity. 27 patients had GSD-I, 24 had GSD-III and 19 had GSDs-VI/IX; ages varied from 0.6 to 35.7 years (median 11.7). 31 (44%) had normal or mild parenchymal changes, and 41% (11/27) of those with GSD-I, 25% (6/24) with GSD-III and 11% (2/19) with GSDs-VI/IX had marked changes. No relationships were found between the ultrasonographic appearances and other indices of metabolic control, including plasma triglycerides, total cholesterol or height standard deviation score. Seven adult patients (21–29 years) were found to have hepatic tumours: six with GSD-I and one with GSD-III. Those with GSD-I and tumours tended to have the more severe hepatic parenchymal changes. We conclude that ultrasonography may be useful in identifying patients with GSD-I at risk of hepatic tumour formation.
Cine magnetic resonance imaging of pulsatile cerebrospinal fluid flow using CSPAMM
Authors: Wayte S C , Redpath T W 
Published: July 2009

Abstract
Spatial modulation of magnetization (SPAMM) is a well established imaging technique which superimposes a tagging pattern on conventional magnetic resonance (MR) images, allowing movement to be visualized. A modification to the SPAMM technique, called complementary spatial modulation of magnetization (CSPAMM), which improves the contrast of the tagging pattern is explained. The application of CSPAMM to the visualization of pulsatile cerebrospinal fluid flow (CSF) using an 8 frame cardiac-gated cine sequence is described. Various combinations of binomial pulses, up to the fifth order, were investigated to see which produces the optimum tagging pattern in the CSPAMM images. The flip angles of the imaging RF pulses were studied to see which would give equal maximum CSF signal intensity in all the cine images. The optimized cine CSPAMM technique was compared in vivo with SPAMM and CSF motion was found to be more easily visualized in the CSPAMM images.
Radioiodine ablation of residual tissue in thyroid cancer: relationship between administered activity, neck uptake and outcome
Authors: Logue J P , Tsang R W , Brierley J D , Simpson W J 
Published: July 2009

Abstract
A retrospective review was performed to evaluate the effectiveness of radioiodine in the ablation of residual thyroid tissue after surgery for differentiated thyroid cancer. 121 patients were treated at the Princess Margaret Hospital, Toronto, Canada between 1977 and 1989, with the activity of radioiodine determined empirically. Ablation of residual thyroid was determined by 131I nuclear scans, using absent visible uptake (compared with background) as the criterion for successful ablation. 97 patients (80%) had successful ablation of residual thyroid tissue after the first administration of radioiodine. Patients with higher iodine uptake in the neck had a tendency to receive higher activities of 131I. There were no statistically significant differences in age, sex, type of surgery, initial iodine uptake in the neck and administered radioiodine activity between those successfully ablated and those that were not. Patients receiving less than 3.7 GBq (100 mCi) tended to have lower iodine uptake (&lt;5% at 24 or 48 h), but their rate of thyroid ablation was just as high as those given 3.7 GBq or more. In order to take advantage of this, we have formalized our approach by deriving guidelines to the empiric determination of radioiodine activity based on the iodine uptake in the neck. Among the 11 patients treated with lobectomy only, the ablation rate was 64%. Although this was not significantly lower than for other forms of surgery, we continue to recommend completion thyroidectomy for this group of patients, if the goal of treatment is to ablate all thyroid tissue.
Tangential breast irradiation—rationale and methods for improving dosimetry
Authors: Neal A J , Mayles W P M , Yarnold J R 
Published: July 2009

Abstract
In recent years there have been great advances and innovations in all technical aspects of radiotherapy, including three dimensional (3D) computer planning, patient immobilization, radiation delivery and treatment verification. Despite this progress, the technique of tangential breast irradiation has changed little over this period and has not exploited these advances. There is increasing evidence that dose inhomogeneity within the breast is greater than at other anatomical sites, especially in women with large breasts. This paper is a review of the factors contributing to poor dosimetry in the breast, the clinical consequences of an inhomogeneous dose distribution, and how breast dosimetry could be improved by considering each of the stages from planning to accurate treatment delivery. It also highlights the particular problem of women with large breasts who may be more likely to have a poorer cosmetic outcome after a fractionated course of radiotherapy than women with small/medium-sized breasts, and supports the clinical impression that such women are also more likely to have greater dose inhomogeneity when 3D treatment plans are examined. Preliminary data from our current computed tomography (CT) planning study are presented to support these observations.
Dynamic contrast-enhanced and fat suppressed magnetic resonance imaging in suspected recurrent carcinoma of the breast: preliminary experience
Authors: Kerslake R W , Fox J N , Carleton P J , Imrie M J , Cook A M , Bowsley S J , Horsman A 
Published: July 2009

Abstract
20 women with suspected recurrent breast cancer who had undergone previous breast-conserving operations were investigated using dynamic contrast-enhanced gradient echo (GRE) and fat suppressed spin echo (SE) magnetic resonance (MR) imaging. Histologically confirmed recurrent tumour was readily recognized on dynamic GRE scans by virtue of rapid, early and avid enhancement. Benign scars enhanced more slowly and reached lower magnitudes of enhancement. Fat suppressed SE images, which were typically acquired lO min after contrast administration, were sensitive for the detection of tumour recurrence but lacked specificity. Early scanning after contrast administration offers the best prospects for distinguishing tumour recurrence from benign scarring. The criteria used to distinguish these two entities are highly dependent on the scan technique and the time at which images are obtained post-contrast.