bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantitative computed tomography for spinal bone mineral measurements in chronic renal failure
Authors: Karantanas A H , Kalef-Ezra J A , Sferopoulos G , Siamopoulos K C 
Published: July 2009

Abstract
The aim of this study was to assess non-invasively the status of spinal trabecular bone in patients with chronic renal failure and the influence of the disease stage. Single energy quantitative computed tomography (CT) was used in 89 patients with chronic renal failure to measure spinal trabecular bone equivalent density. 23 patients were independent of dialysis and 66 were receiving long-term haemodialysis. Spinal trabecular bone density of the patients was compared with locally determined normal ranges. Although trabecular bone mineral density (BMD) was lower (9% on average) in the patients who were not dependent on dialysis compared with the predicted mean normal values (BMDp) for age- and sex-matched normal subjects, the difference was not statistically significant. A statistically significant reduction was found in patients on dialysis (BMD/BMDp 0.75±0.16, Z-score – 1.3). Osteosclerosis was found in 11 patients and they were excluded from the study. Longitudinal measurements in 42 patients on dialysis without osteosclerosis showed a 2.9% mean reduction in BMD/BMDp over a period of 8 months. All but one of the 16 haemodialysis patients with osteopenic spinal fractures had trabecular BMD values lower than the fracture threshold determined by our technique. In conclusion, end-stage chronic renal failure was associated with reduction in the spinal trabecular bone density.
Vertebral deformity in the thoracic spine in post-menopausal women: value of lumbar spine bone density
Authors: Grey C , Young R , Bearcroft P W P , Compston J E 
Published: July 2009

Abstract
Differential bone loss in the thoracic and lumbar spine is known to occur in some patients with osteoporosis. However, the discriminant value of lumbar spine bone densitometry in the detection of thoracic spine fractures in healthy, population-based women has not been established. The relationship between lumbar spine bone mineral density and thoracic spine vertebral deformities in a prospective study of 79 post-menopausal population-based women aged 45–65 years has been investigated. Lumbar spme bone mineral density was measured using dual energy X-ray absorptiometry, and vertebral morphometry was assessed from lateral thoracic spine radiographs. Seven women (9%) were found to have one or more vertebral deformities in the thoracic spine (reduction in anterior or posterior height &gt; 25%). Only one of these had a lumbar spme bone mineral density T score below − 2.5, whilst the T score was between − 1 and − 2.5 in three and greater than − 1 in three. Two of these women also had lumbar spine vertebral deformity but lumbar spine radiographs were normal in the remaining five. There were no significant differences in age, height, weight, hormone replacement therapy use or bone mineral density between women with and without thoracic spine fractures. These results demonstrate that vertebral deformities in the thoracic spine occur in a proportion of healthy post-menopausal women in the absence of densitometric or radiographic evidence of osteoporosis in the lumbar spine. Although often asymptomatic, the significance of these fractures lies in the increased risk of further fractures. In the future, morphometric X-ray absorptiometric techniques may prove valuable in the detection of these fractures and avoid the need for conventional radiography.
An experimental investigation of the effect of light-box luminance on the detection of low contrast objects in mammography
Authors: Robson K J , Kotre C J , Faulkner K 
Published: July 2009

Abstract
It has been hypothesized that light-box luminance is an important factor in the detection of objects on radiographs. In this work, existing psychophysical data relating to the measurement of visual thresholds at various scene luminance levels are applied to the problem of the observation of radiographs on a light-box. These data suggest that for a given stimulus size, the threshold contrast varies little over several orders of magnitude of scene lummance. In a series of contrast detail experiments performed over a wide range of lightbox lummances it has been demonstrated that the detection of low contrast objects on mammographic film is dominated by external noise, that is noise on the film, rather than the internal visual noise of the observer. It is therefore suggested that in mammography it is inappropriate to base recommendations for optimal values of light-box luminance on psychophysical studies of visual noise. It has been shown that commonly used light-box luminances are suitable for viewing mammograms at the higher average optical densities now being recommended, provided that precautions are taken to avoid glare and reflection.
Dose–area product values in frequently performed complex paediatric radiology examinations
Authors: Ruiz M J , Vañó E , González L , Fernández J M 
Published: July 2009

Abstract
Mean values of the dose–area product for barium meal, micturating cystourethrography and intravenous urography examinations from three health centres and for four age groups are presented in this study. Values measured are between 13% and 86% higher than results previously reported, which justifies the importance of applying procedures which reduce risks to patients.
Imaging of central nervous system sarcoidosis with gallium-67 single photon emission computed tomography
Authors: Jarman P R , Whyte M K B , Glass D M , Peters A M 
Published: July 2009

Abstract
Involvement of the nervous system is an uncommon and underdiagnosed complication of sarcoidosis. We used gallium single photon emission computed tomography (SPECT) to define areas of meningeal involvement in a patient with neurosarcoidosis. This technique may be of value in the assessment of patients with sarcoidosis and suspected central nervous system involvement.
Time-course changes of contrast enhancement in iron colloid enhanced MRI in patients with hepatocellular carcinoma
Authors: Suto Y , Ametani M , Kamba M , Sugihara S 
Published: July 2009

Abstract
Time-course changes in contrast enhancement of chondroitin sulphate iron colloid (CSIC), an MR contrast agent, were determined in 12 patients with 20 lesions of classical hepatocellular carcinoma (HCC). Spin echo T 1 weighted (T 1 WI) and T 2 weighted images (T 2WI) were obtained before administration of CSIC and 1, 6 and 24 h after injection. The signal-to-noise ratio (SNR) in the tumour region and the liver and the tumour-to-liver contrast-to-noise ratio (CNR) were calculated, and time-course changes of these ratios were determined. SNRs for tumour before the administration of contrast medium did not differ significantly from SNRs after administration on T 1WI or T 2WI SNRs for the liver on both T 2WI and T 2WI were significantly lower at each time point after administration than before administration. The tumour-to-liver CNRs for both T 1WI and T 2WI were significantly higher after administration than before administration The maximum CNR was observed 6 h after administration on both T 1WI and T 2WI. The contrast enhancement was maintained for at least 24 h, with a peak at 6 h after administration. The prolonged enhancement obtained with CSIC has extended the time during which effective contrast is maintained.
Measurement of spin-lattice relaxation times with FLASH for dynamic MRI of the breast
Authors: Brookes J A , Redpath T W , Gilbert F J , Needham G , Murray A D 
Published: July 2009

Abstract
Using a variable flip angle gradient refocused imaging technique, dynamic quantitative T 1 relaxation maps acquired before and after the administration of a gadolinium contrast bolus enable the concentration–time curve of the paramagnetic agent in breast tissue to be calculated. This imaging technique has the aim of improving the diagnostic accuracy of MR mammography. Measurements with phantoms of calibrated T 1 values have been carried out to investigate the accuracy of the method, with particular reference to errors caused by incomplete spoiling of residual transverse magnetization and inaccurate radio frequency (RF) flipangle settings. A clinical example is presented. The method has potential use for any patient study which necessitates rapid quantitation of changing in vivo T 1 values as a result of contrast agent injection.
The imaging performance of a storage phosphor system for dental radiography
Authors: Brettle D S , Workman A , Ellwood R P , Launders J H , Horner K , Davies R M 
Published: July 2009

Abstract
Direct digital imaging systems are becoming increasingly common in dental radiography. The majority of these systems are based on charge coupled device (CCD) technology. A relatively new system, based on photo-stimulable phosphor luminescence (PSPL), is now commercially available. This system appears to overcome some of the restrictions of CCD systems including those associated with the bulky detector, connecting wire, limited image size and limited exposure latitude. A physical evaluation of the PSPL system was conducted including measurements of sensitometric response, modulation transfer function (MTF), noise power spectrum (NPS), noise equivalent quanta (NEQ) and detective quantum efficiency (DQE). These measurements were compared with results obtained previously for Kodak Ektaspeed (E-speed) film. The results of the evaluation indicate that the PSPL system may be capable of operating at exposures up to 80% lower than for film with comparable image quality.
Computerized planimetry in the objective assessment of the antispasmodic effect of Zamifenacin in double contrast barium enemas
Authors: Hughes T , Wright A R , Owen J P , Keir M J 
Published: July 2009

Abstract
A prospective, randomized, double-blind study was undertaken to evaluate Zamifenacin 30 mg (Pfizer Ltd), a novel, orally-administered, gut-specific muscarinic receptor antagonist, as an adjuvant to the double contrast barium enema examination (DCBE). Zamifenacin was compared with placebo in terms of side-effects and colonic tone. Analysis of colonic tone was carried out by two independent observers, using a subjective grading system and also by an objective method using computerized planimetry. Interobserver variability was also assessed. Zamifenacin is safe and well tolerated but at the prescribed dose is an ineffective antispasmodic for DCBE. Subjective assessment of colonic tone was shown to be of limited value whilst the objective analysis using computerized planimetry was reliable and highly reproducible.
Consistency of film optical density in mammographic screening programmes
Authors: Law J 
Published: July 2009

Abstract
Maintaining a constant and appropriate mean film optical density in mammography is an essential part of quality assurance in a breast screening programme. It depends on stability in X-ray exposure controls, film supplies, intensifying screens and film processing. A programme of weekly monitoring is described which helps to trace the source of any irregular or step-wise changes in any of the relevant parameters. Its results are also used to investigate by statistical methods the degree of film optical density variation achieved in periods of several weeks of apparent general stability. Results are presented for 20 X-ray sets and a total of 32 record periods of 8–10 weeks each. The mean standard deviation for density of a single film of a Perspex block was found to be 3.5%. For processor speed index it was the same while for X-ray set variations it was less than 2%. Neither of these last two variables showed any strong correlation with block film optical density.
Oesophageal tumour volume measurement using spiral CT
Authors: Liang E Y , Chan A , Chung S C S , Metreweli C 
Published: July 2009

Abstract
A CT technique for measuring oesophageal cancer tumour volume in the monitoring of local disease response following radiotherapy or chemotherapy is described. Patients with newly diagnosed oesophageal carcinoma were referred for pre- and post-chemotherapy CT scans. IV Buscopan was given to abolish peristalsis. Patients were scanned in prone position. Effervescent gas granules and Calogen (a negative contrast of fat density) were given. Spiral scanning was performed. The area of tumour on each 1 cm slice was measured. The sum of these areas gave tumour volume in cubic centimetres. The accuracy of the method was tested on patients who had had surgery. The volume of the segment of oesophagus containing tumour was measured by its weight and water displacement. Lumenal distention proximal and distal to the tumour was achieved in all patients. 10 gross surgical specimens were available for comparison with pre-operative CT. The correlation coefficient was 0.95. In conclusion, accurate tumour volume assessment was achieved with our technique.
Phrenic artery injury—a rare complication of percutaneous needle lung biopsy
Authors: Padhani A R , Scott W W 
Published: July 2009

Abstract
The phrenic artery is a small vessel that is not often visualized on CT and is at risk of injury during biopsy of low lung lesions. This may result in haemoperitoneum that will not be evident on post-biopsy chest X-rays. We present a patient with a bleeding tendency who had this unusual complication following a needle aspiration lung biopsy.
Pneumocystis carinii pneumonia presenting as a solitary cavitating lung lesion in non-HIV immunosuppressed patients
Authors: Uwyyed K , Bar-Ziv J , Kramer M R 
Published: July 2009

Abstract
Pneumocystis carinii is one of the most common pulmonary opportunistic infections in immunodeficient patients. It has a classical chest radiographic appearance of bilateral interstitial infiltrates. Recently, cystic or cavitating lesions have been reported in HIV patients with Pneumocystis carinii pneumonia. We report two cases of non-AIDS immunosuppressed patients with the unusual presentation of a solitary cavity in the lung.
Paravesical suture granuloma resembling bladder carcinoma on CT scanning
Authors: Carroll K M , Sairam K , Olliff S P , Wallace D M A 
Published: July 2009

Abstract
Paravesical granuloma formation is a rare complication of inguinal herniorrhaphy. Infected non-absorbable suture material is the usual cause. We present a case of paravesical granuloma that was initially thought to be bladder carcinoma both clinically and on CT scanning. The patient presented with urinary symptoms. Repeated biopsies revealed only reactive changes with no evidence of malignancy. CT showed a mass which appeared to arise from the anterior aspect of the bladder with a central area of low attenuation. The diagnosis was established at cystoscopy with deep resection of the mass, when two retained silk stitches with surrounding pus and granulation tissue was found. The diagnosis of paravesical suture granuloma (PSG) should be considered in patients with suprapubic symptoms, no haematuria, an atypical mass and a history of herniorrhaphy, which may have been many years prior to the time of presentation.
Radiation properties of a miniature X-ray device for radiosurgery
Authors: Biggs D S , Thomson E S 
Published: July 2009

Abstract
An alternative technology for performing interstitial intracranial radiosurgery is presented. Treatments are performed intraoperatively using a stereotactically mounted, miniature X-ray device. A concentrated, spherical pattern of X-rays is generated about the tip of a needle-like probe, which is inserted into the site of the lesion allowing the absorbed dose to healthy tissue to be minimized. A description of the device is given and results of investigations into the operating characteristics discussed.
Dose and image quality in mammography with an automatic beam quality system
Authors: Young K C , Ramsdale M L , Rust A 
Published: July 2009

Abstract
Radiation dose, contrast and image quality for automatic beam quality selection (OPDOSE) with the Siemens Mammomat 3000 has been investigated for different breast thicknesses and compared with those found using manually set tube potentials and a molybdenum target and filter. Automatic beam quality selection was found to have a negligible effect for breasts with a compressed breast thickness of less than 45 mm. However, for larger breasts substantial dose savings were achieved for a loss in contrast. For mammograms of compressed breasts with a thickness in excess of 60 mm the mean glandular dose (MGD) per film was 2.90 mGy for manually selected tube potentials with a molybdenum/molybdenum target filter combination as compared with 1.87 mGy using 26 kVp and a tungsten target with rhodium filtration. The contrast loss in using OPDOSE was measured with a test object to be about 10% for breast thicknesses in excess of 45 mm. The standard breast model, which assumes a 50% glandular content, did not provide a good fit to the MGD for women attending for breast screening in the age range 50 to 64 years.
Renal function and the excretion of contrast agents
Authors: Dawson P , Peters A M 
Published: July 2009

Abstract
The renal excretion of intravascular iodinated X-ray and gadolinium chelate MR contrast is examined theoretically. An expression is derived for the proportion of an administered dose of such an agent excreted in any given time in the face of varying levels of renal function. It is shown that a family of curves may be generated from which an estimate of this proportion for any time may be made. Some circumstances in which such knowledge may be useful are briefly discussed.
Kaposi's sarcoma of the rectum—treatment with radiation therapy
Authors: Kaufmann T , Nisce L Z , Coleman M 
Published: July 2009

Abstract
The number of patients afflicted with the acquired immune deficiency syndrome (AIDS) is on the rise. About 30% of AIDS patients develop Kaposi's sarcoma. Although the skin is the most common site of involvement, lesions may encompass the gastrointestinal tract. The purpose of this report is to describe a patient with AIDS related Kaposi's sarcoma of the rectum, successfully treated with radiation therapy. We believe this to be a useful technique in the treatment of this condition.
Nasolacrimal duct opacity on CT
Authors: Loftus W K , Kew J , Metreweli C 
Published: July 2009

Abstract
A retrospective analysis of 100 coronal sinus CT scans was performed to investigate the frequency of opacity of the nasolacrimal duct and determine if there was any correlation between the pattern of duct opacity and the presence of inflammatory sinus disease. The study showed that the nasolacrimal ducts are opaque in the majority of normal people and that there is no relationship to inflammatory sinus disease.
Detection of early scirrhous carcinoma of the stomach by endoscopic ultrasonography
Authors: Fujishima H , Chijiiwa Y , Nawata H 
Published: July 2009

Abstract
The endoscopic ultrasonography (US) characteristics of early scirrhous carcinoma of the stomach (ESS) were evaluated in four patients. ESS was defined as the presence of poorly differentiated carcinoma cells spreading through the submucosa and muscularis propria in association with a marked desmoplastic reaction without serosal invasion. ESS was characterized by localized irregular hypoechoic enlargement of the third (sub-mucosal) and the fourth (muscularis propria) layers. The fifth (serosal) layer was normal. The third and fourth layers showed a threefold increase in thickness compared with the thickness of these layers in healthy subjects. Our results suggest that endoscopic US is useful for diagnosis of ESS.
Endoanal ultrasound during contraction of the anal sphincter—improved definition and diagnostic accuracy
Authors: Rieger N A , Downey P R , Wattchow D A 
Published: July 2009

Abstract
Endoanal ultrasound was used in the investigation of 26 patients with faecal incontinence. In each case images of the anal sphincter were taken at rest and during contraction or squeezing (dynamic). Better definition of the normal anal sphincter or anal sphincter defects was obtained in 16 (62%) of the patients with imaging during contraction. In eight of the 13 patients with a sphincter defect there was better definition of the defect and increased separation of the ends of the sphincter during contraction. Imaging during contraction improves diagnostic accuracy and is a useful adjunct with endoanal ultrasound.
Patterns of chronic adhesive arachnoiditis following Myodil myelography: the significance of spinal canal stenosis and previous surgery
Authors: Laitt R , Jackson A , Isherwood I 
Published: July 2009

Abstract
109 patients who had undergone Myodil myelography on at least one occasion were identified. The patterns of lumbar nerve root distribution in this group were examined using magnetic resonance imaging. The relationship between these patterns and the presence of spinal stenosis or previous surgery was investigated. Chronic adhesive arachnoiditic nerve root patterns were seen in 68 patients and were classified into three groups according to Delemarter et al. Central clumping of nerve roots (type 1) and complete opacification of the thecal sac (type 3), extending over at least one vertebral level, were significantly related to spinal stenosis at an adjacent level (p&lt;0.0001). Peripheral adhesion of nerve roots to the theca (type 2) was significantly related to previous surgery at the level of abnormality (p&lt;0.00005). Only a single case of arachnoiditic nerve root patterns was seen in the absence of stenosis or previous surgery. We conclude that chronic adhesive arachnoiditis is significantly related to previous Myodil myelography in the presence of spinal stenosis or previous surgery but that Myodil alone rarely produces these changes.
MRI as an aid to the fitting of tracheo-oesophageal Blom–Singer valves post-laryngectomy
Authors: Brunton J N , Needham G , Mickleburgh J E 
Published: July 2009

Abstract
The Blom–Singer valve is a device for facilitating speech in patients who have undergone total laryngectomy. The valve is inserted into a surgically created tracheo-oesophageal fistula. Fitting the valve and determining the correct length and direction of the fistula, although usually straightforward, can be difficult. We describe two patients in whom MR imaging of the fistula tract has aided valve fitting.
The influence of air cavities on the optic chiasm dose during pituitary radiotherapy for acromegaly
Authors: Jones B , Samarasekara S , Tan L T , Mayles W P M 
Published: July 2009

Abstract
The treatment planning of acromegalic patients can be complicated by the presence of abnormally large frontal air sinuses which allow increased anterior beam transmission causing increased dose to the optic nerve and chiasm which, if excessive, can result in blindness. This potential problem has been investigated by computer treatment planning exercises which have allowed for a variable thickness (1–3 cm) of air cavity beneath the frontal field and for different weightings of the lateral opposed fields relative to the anterior field. The resultant overdosage can be greater than 5% of the intended dose. The increased biological effect from errors of this magnitude is sufficient to increase the risk of optic nerve damage since neural tissue is very sensitive to small increments in fraction size. Even when the reduced attenuation is allowed for in the computer plan, the thickness of the air sinuses varies across the field so that irradiation through the frontal enlarged frontal air sinuses causes inhomogeneous dose distributions in the target volume. Acromegalic patients should therefore be treated with a more superior beam which would avoid the air sinuses altogether.