bluuebunny/crossref_metadata_2025_split huggingface dataset:
A re-evaluation of magnetic resonance imaging damping loops
Authors: McRobbie D W 
Published: July 2009

The measurement of signal-to-noise ratio and contrast-to-noise ratio (SNR and CNR) forms an essential part of performance assessment or image quality assurance (QA) procedures in magnetic resonance imaging (MRI). When a patient is present within the scanner there is an interaction between the radiofrequency (RF) coils and electrically conducting tissue. This interaction is commonly referred to as loading. Its main consequences are the detuning of the coil resonant frequency, the generation of additional noise and the changing of the impedance of the coil as seen by the preamplifier. It is therefore essential that a means of simulating patient loading is applied in performance evaluation and QA procedures.
Edelstein et al (1984) offered an elegant solution for simulating loading using an inductive damping loop. The use of damping loops was further investigated by Jennings et al (1986) who concluded that the same loop could not be used at different imaging frequencies (field strengths). The present work constitutes a re-evaluation of the use of damping loops which contradicts these earlier findings.
The effect of loading on the coil can be represented by the addition of a further series resistance Rm to the coil resistance Rc. The effective loaded coil quality factor (Q1) is then: where ω0 is the coil resonant angular frequency (2πf) and L is the coil inductance.
Comparison of technetium 99m nanocolloid and indium 111 leucocytes in the diagnosis of orthopaedic infections
Authors: Ooi G C , Belton I , Finlay D 
Published: July 2009

Abstract
It has been suggested that technetium 99m nanocolloid is as effective an inflammatory radiopharmaceutical as indium 111 leucocytes. This study compares the efficacy of 99Tcm nanocolloid and 111In leucocytes in the detection of orthopaedic infection in 19 patients with a high clinical suspicion of infection. The two scintigrams were performed within 24 h of each other. A scintigram was considered positive where there was an increase in tracer uptake at the site of interest. Concordance rate of 73% was achieved. The numbers of false positives with 111In leucocytes and 99Tcm nanocolloid were three and six respectively. The single false negative in both was of a patient with tuberculous spondylodiscitis. Sensitivity was 75% in both. Specificities were 79% and 60% for 111In leucocytes and 99Tcm nanocolloid respectively. Positive Predictive Value was only 33% with 99Tcm nanocolloid and 50% with 111In leucocytes. 99Tcm nanocolloid also proved less reliable in accurately detecting infected prostheses. We conclude that 99Tcm nanocolloid cannot replace 111In leucocytes in the diagnosis of orthopaedic infections.
Late pulmonary scintigraphic defects after uneventful recovery from simple focal pneumonia of childhood
Authors: Kenney I J , Lenney W , Lutkin J E , Gordon I 
Published: July 2009

Abstract
We present a pilot study designed to determine whether pneumonia in children accompanied by focal consolidation on the chest radiograph (CXR) is associated with late abnormality as detected by radionuclide lung scintigraphy. 14 children with focal pneumonia were assessed 1 year after initial presentation. In 12 both krypton-81m ventilation and technetium-99m MAA perfusion studies were performed, while in two only perfusion studies were obtained. All cases had a further CXR. Abnormal or equivocal cases were reviewed clinically. Scans and CXRs were independently assessed by two observers and subsequently consensus reached by discussion. There were five abnormal and nine normal lung scans. Two defects matched the site of the initial pneumonia while three did not. A CXR at the time of lung scanning was normal except for one case with a small focus of consolidation on the opposite side to the initial pneumonia but with a normal lung scan. Similarly, clinical assessment at the time of scanning was unremarkable, with no history of further respiratory episodes except in one child excluded from the study because of an interval diagnosis of asthma. This pilot study indicates that lung scan defects are common in the medium term after supposedly uncomplicated pneumonia in childhood. The cause of these defects remains uncertain. The correlation with the site of the initial radiological abnormality is variable, pointing to the need for further research in this area. The importance of independent blind interpretation is also highlighted.
The safety of outpatient arteriography using 3F catheters
Authors: Reidy J F , Ludman C 
Published: July 2009

There has been a general trend for diagnostic arteriography to be performed as a day-case procedure, thus obviating the need for hospital admission. Most commonly 5F and, more recently, 4F catheters have been used via the femoral approach.
After catheter removal, firm digital pressure is applied at the puncture site for 10–15 min following which patients are observed for 2–4 h. Although this approach is undoubtedly safe, problems may arise, particularly in elderly patients, those with hypertension and also in patients with groin scarring, often associated with surgical bypass grafts. Severe bleeding is very rare, but a haematoma or delayed oozing is not unusual. In a recent paper advocating outpatient arteriography with 4F catheters there was no delayed bleeding, but over half the patients had bruising in the groin or slight oozing following the procedure (Dyet et al, 1990). The ages of these patients were not specified but there is nothing to suggest that they were a particularly “atrisk” group.
Ovarian cystic teratomas: value of chemical fat saturation magnetic resonance imaging
Authors: Imaoka I , Sugimura K , Okizuka H , Iwanari O , Kitao M , Ishida T 
Published: July 2009

Abstract
Chemical fat saturation (FS) magnetic resonance imaging (MRI) for the characterization of ovarian cystic teratoma was evaluated in 19 patients with 22 lesions. The tumour was evaluated for signal intensity, location and size; the presence of chemical shift artefact, debris and fat-fluid level. Ovarian cystic teratoma was diagnosed prospectively if the mass contained fat and/or more than one type of internal pattern on (1) SE T 1-, T 2-, (2) SE T 1-, T 2-, FS T 1,-weighted images. A correct diagnosis was reached in 17 of 22 tumours on conventional T 1- and T 2-weighted images, and in 21 of 22 tumours when fat-saturation images were added. When fat-saturation images were added, four of five tumours misdiagnosed on conventional images were then correctly diagnosed. These tumours contained only small amounts of fat. Fat-saturation images could detect smaller amounts of fat than conventional images. However, one tumour did not show decreased intensity on fat saturation images, and was not diagnosed even when fat-saturation images were added. Fat saturation images have been shown to be of value in diagnosing cystic teratomas.
The biology and radiobiology of in utero development in relation to radiological protection
Authors: Mole R H 
Published: July 2009

Abstract
Aspects of intrauterine development relevant to radiological protection but not considered in the recently revised Recommendations of ICRP (1991a) include (i) recently acquired evidence on the totipotency of cells of the morula with implications for dosimetry and risk in the first week of human development in utero; (ii) much older evidence on the earliest stages of myelo- and lymphopoiesis in the human subject that bears on radiosensitivity to leukaemia induction in utero; (iii) much older evidence on species differences that may affect the application to the human of experimental work on radionuclide transport from mother to embryo and fetus; (iv) recent proposals of alternative mechanisms for localization of functions in the developing mammalian forebrain with implications for risk of mental impairment caused by low level irradiation in utero, and (v) a recent demonstration that UNSCEAR (1977) was mistaken when concluding that a high radiosensitivity for teratogenesis is characteristic of the embryo and of preimplantation irradiation. The 1990 Recommendations of ICRP (1991a) to limit exposure of the fetus to radionuclides by reference to the occupation ALI for adults, i.e. women of reproductive age, seems to be a serious mistake.
The role of intravenous cholangiography in pre-operative assessment for laparoscopic cholecystectomy
Authors: Patel J C , McInnes G C , Bagley J S , Needham G , Krukowski Z H 
Published: July 2009

Abstract
With the advent of laparoscopic cholecystectomy, pre-operative identification of calculi in the common bile duct has become increasingly important. In patients without clinical or biochemical evidence of common bile duct calculi, debate continues as to the value of intravenous cholangiography (IVC) as a screening modality for the detection of unsuspected choledocholithiasis. In a prospective series of 180 patients, IVC was used to assess the common bile duct in 113 patients at low risk of choledocholithiasis, 51 patients at high risk underwent endoscopic retrograde cholangiography (ERC) and sphincterotomy if indicated, and in 16 patients, for a variety of reasons, no pre-operative cholangiography was performed. 31% of those who had ERC and two (1.8%) of those who had IVC had duct calculi. These data do not support the routine use of IVC in patients with no evidence of common bile duct calculi and its routine use has been discontinued.
Latent image fading in mobile mammographic screening
Authors: Law J 
Published: July 2009

I should like to comment in support of the letter by Robson et al (1992) and to provide further data on this topic, which is one of some concern to Breast Screening Programmes in remote areas.
The film–screen system used in the Edinburgh Breast Screening Centre at the start of the national screening programme was Fuji NH film with Fuji Hi-Mammo screens and cassettes. This system was tested for latent image fading in July 1989, when 24 radiographs of a “Baits” phantom (White & Tucker, 1980) were obtained in under 1 h. The X-ray exposures were made on a Siemens Mammomat 2S unit in a screening van. This X-ray unit was chosen in preference to the units then available at the Centre because of the high reproducibility of its X-ray output. Of these 24 films, six were processed about 1 h after exposure (the shortest practicable time), six after a further 24 h, six at 1 week after exposure and the last six at 3 weeks after exposure. The mean background density of each set of six films is given in Table I, after correction for small changes in sensitometry speed index of the processor.
Radiological appearances in peliosis hepatis
Authors: Jamadar D A , D'Souza S P , Thomas E A , Giles T E 
Published: July 2009

Abstract
Peliosis hepatis is an unusual disorder characterized by blood filled hepatic spaces. We describe the appearances of this entity on ultrasonography, computed tomography and magnetic resonance imaging. The importance of peliosis hepatis is that it may be an indicator of a treatable underlying condition.
Identification of inappropriate radiological referrals with suspected gallstones: a prospective audit
Authors: Farrell T , Mahon T , Daly L , Masterson J 
Published: July 2009

Abstract
The objective of this study was to derive and test a clinical scoring system in order to predict the presence of gallstones and to identify inappropriate referrals. The design of this scoring system comprised a prospective audit of all referrals with suspected gallstones and a prospective validation of the system on new patients. The subjects used in the study consisted of 300 inpatient, outpatient and general practitioner referrals to a radiology department with suspected gallstones during the period 1984–1986 (1st cohort) and 200 similar referrals from 1987 to 1988 (2nd cohort). The main outcome measures were gallstones as determined by oral cholecystogram and/or ultrasound of the gallbladder. 32.7% and 24.0% of referrals in the first and second cohorts, respectively, had gallstones. A scoring system to predict gallstones was derived on the first cohort based on age, Murphy's sign, duration and type of pain, presence or absence of flatulence, and source of referral. This scoring system discriminated well between those with and without stones in both cohorts. Low risk groups, comprising about 15% of the referrals in each cohort, were identified with a prevalence of gallstones of 4.5% (1st cohort) and 3.0% (2nd cohort). If these patients had not been referred the radiological workload would have dropped by 15%, with a very small reduction in diagnostic yield. We conclude that prior to radiological assessment it is possible, on the basis of source of referral and symptoms, to identify a group of patients with a low prevalence of gallstones. These cases, with a low diagnostic yield, contribute substantially to the workload of a radiological department.
Effect of overall time when radiotherapy includes teletherapy and brachytherapy: a mathematical model
Authors: Jones B , Bleasdale C 
Published: July 2009

Abstract
By expanding the linear quadratic equations to allow for the interval of time between teletherapy and brachytherapy in a model which assumes continual exponential tumour regression following teletherapy, the loge cell kill resulting from brachytherapy is found to depend on radiosensitivity, tumour regression rate (λ) and tumour clonogen doubling time (T p). When λ is relatively small the precise timing of brachytherapy following teletherapy is shown to influence the tumour cure probabilities. The model predicts a reduction in tumour control if brachytherapy is delayed when λ values are small and T p values are short, but when T p values are long, deferral of brachytherapy may be advantageous. By differential calculus the occurrence of a minimum value of log cell kill can be found. Application of these concepts may improve the results of clinical radiotherapy.
A newborn case of chondrodysplasia punctata, tibia-metacarpal type
Authors: Matsui M. , Honma Y , Oguro N , Shiraishi H , Kobayashi S , Yanagisawa M , Nakamura K 
Published: July 2009

Abstract
Chondrodysplasia punctata, tibia-metacarpal type, was diagnosed in a Japanese neonate with short limbs, based on the characteristic radiological findings of widespread calcific stippling in the epiphysis, tarsal area and the sacrum, and dysplasias with predominant involvement of the tibiae and metacarpals.
Diagnostic pharmaco-scintigraphy with hepatic intraarterial technetium-99m macroaggregated albumin in the determination of tumour to non-tumour uptake ratio in hepatocellular carcinoma
Authors: Lau W Y , Leung T W T , Ho S , Chan M , Leung N W Y , Lin J , Metreweli C , LI A K C 
Published: July 2009

Abstract
Between October 1990 and March 1993, 124 patients who had hepatocellular carcinoma (HCC) underwent diagnostic pharmaco-scintigraphy with hepatic intraarterial technetium-99m macroaggregated albumin (TcMAA) to determine the tumorous to non-tumorous liver tissue uptake ratio (T/N ratio). There were 110 males and 14 females. Ages ranged from 16 to 73 with a median of 55 years. The range of T/N ratio was 0.7 to 19.3 with a median of 3.8. 12 patients with inoperable HCC were subsequently selected by predetermined criteria to undergo treatment with hepatic intraarterial yttrium-90 microspheres and the T/N ratios in these patients were validated by beta probe dosimetry and liquid scintillation count of multiple liver biopsies. The T/N ratio determined by preoperative diagnostic TcMAA scan correlated well with intraoperative beta probe dosimetry, with coefficient of correlation r = 0.82. Preoperative TcMAA scan also correlated well with liquid scintillation count of biopsy specimens, with r = 0.96. We conclude that TcMAA scan can be used to determine the T/N ratio in patients with HCC, thus allowing better selection of patients with inoperable tumours for loco-regional therapy.
Book review
Authors: Gleeson J A 
Published: July 2009

It is rare to be able to recommend a text book without reservation, happily in this case one can do so.
Radiology of the Small Bowel is an excellent well written book with superb illustrations and up-to-date references from a wide range of sources. For the most part it confines itself to the changes found on “luminal contrast studies” but this is not to the complete exclusion of other methods of investigations when considered of value in reaching a diagnosis.
Comparison of a new dual characteristic film–screen system (Insight) with a standard film–screen system for chest radiology
Authors: Logan P M , Tunney T , McCoy C T , Masterson J 
Published: July 2009

Abstract
A new dual image receptor screen–film combination has been developed by Kodak with the objective of improving mediastinal and retro-cardiac detail whilst retaining good contrast and detail in the lung fields. This system was compared with our standard chest system. The study population was 36 patients with sarcoidosis. A postero-anterior (PA) chest film using our standard system was followed by a PA chest film using the new system—both using high kVp technique. The pairs of radiographs were assessed for (1) presence or absence of lymphadenopathy; (2) visibility of anterior and posterior mediastinal and azygooesophageal lines; (3) visibility of vessels in the outer and inner thirds of the lungs and (4) visibility of infiltrates, if present. The new film–screen combination was judged to show the mediastinal structures better in almost all instances. However, our standard combination was preferred for lung detail visualization in most cases. No significant difference was found between the two systems in their ability to demonstrate lymphadenopathy. The results were almost unchanged when the observers were given the option to score the criteria as equally well demonstrated on both films as opposed to not having this option available. We feel the advantages of the Insight system do not compensate for the significant loss of parenchymal detail resulting from the use of this system.
Image quality and patient dose for different screen–film combinations
Authors: Guibelalde E , Fernández J M , Vañó E , Llorca A , Ruiz M J 
Published: July 2009

Abstract
Comparisons of image quality and estimations of dose reductions were made for several new screen–film combinations including conventional and rare-earth systems under conditions similar to abdomen radiography. The evaluation was carried out using an ANSI type phantom and the TOR(CDR) image quality object developed by the University of Leeds. The parameters employed for the comparison were: entrance dose, high and low contrast threshold sensitivity and resolution. The advantages and limitations of the method are also discussed. Results show that images with high quality can be obtained with comparatively low patient doses, and that there are still wide differences in image quality for similar speed systems, depending on the manufacturer and on the chosen combination.
Metastatic malignant testicular teratoma of the thymus
Authors: Phillips C J 
Published: July 2009

Abstract
Metastasis of malignant testicular teratoma to numerous sites is recognized and thymic hypertrophy following chemotherapy is frequently seen. The finding of metastatic malignant testicular teratoma in the thymus described here illustrates a further cause of thymic enlargement in this group of patients, which has not been previously reported.
Radiology of stromal sarcoma of the breast with ossifying pleural metastases
Authors: Roditi G , Prasad S 
Published: July 2009

Abstract
Stromal sarcoma of the breast is a rare tumour, the radiology of which has not been to our knowledge properly documented: the case presented returned to medical attention with a large, apparently calcifying pulmonary mass. This proved to be an ossifying pleural metastasis at thoracotomy, when a second smaller, unsuspected similar lesion was found. The radiological findings (including mammography and CT) are reviewed. The role of the radionuclide bone scan (the full significance of which was not appreciated preoperatively) is discussed.
Plain chest radiographic changes of the absent pulmonary valve syndrome
Authors: Owens C M , Rees P , Elliot M , Shaw D 
Published: July 2009

Abstract
The plain chest radiographs of 40 patients with the absent pulmonary valve syndrome in association with tetralogy of Fallot have been reviewed. The conventional frontal projection showed characteristic changes of massively dilated central pulmonary arteries with normal peripheral markings in all patients (100%). Lobar hyperinflation was present in a significant proportion of the infant group (38%) which in a smaller group can be a complication requiring surgery in addition to that for the cardiac malformation.
Ultrasound diagnosis of obstructed Roux loop after cancer of the pancreas or bile duct
Authors: Holland C L , Olliff S P , Olliff J F 
Published: July 2009

Abstract
We describe three cases with known pancreatic or bile duct neoplasia treated by surgery who subsequently presented with obstructive jaundice. In all cases ultrasound demonstrated a fluid-filled obstructed Roux loop and a patent biliary–enteric anastomosis. The cause of the obstruction was seen in two cases. Ultrasound is a safe, fast, reliable and non-invasive method in the assessment of these patients.
Communication makes all the difference
Authors: Gill K P , Hine A L 
Published: July 2009

A 64-year-old man was admitted for excision of a mass in the right groin. The mass had been present for 6 months and had recently enlarged. The patient had noticed aching at the end of the day. His past history was non-contributory.
On clinical examination a fixed hard mass was palpated in the right groin. A similar mass was present in the left groin. A computed tomography (CT) scan of the pelvis was arranged (Figure 1).
A method and contrast–detail phantom for the quantitative assessment of radiotherapy portal imaging systems
Authors: Harrison R M , Lambert G D 
Published: July 2009

Abstract
Several designs of electronic portal imaging systems for radiotherapy have been reported or are now commercially available, as well as the familiar radiographic screen-film combinations. In order to evaluate imaging performance of these, and future, systems a prototype contrast-detail test object has been developed in conjunction with a method for determining contrast from a model of the X-ray spectra produced by linear accelerators. Several existing test objects rely on qualitative or semi-quantitative estimates of contrast. In this technique, quantitative estimates of contrast may be determined for each detail size from realistic estimates of the X-ray spectrum by using a spectral model either in conjunction with narrow-beam attenuation measurements on the linear accelerator used, or by using the nominal value of maximum photon energy. This technique should facilitate the comparison of imaging systems used with linear accelerators of different energies as well as providing a quantitative quality control tool for regular measurements of imaging performance. Examples of the use of the test object in the evaluation of several commercial screen-film combinations are given.
Ultrasound guided transvaginal drainage utilizing a 7 French pig tail balloon catheter
Authors: Bangsbøll S , Karstrup S 
Published: July 2009

Abstract
Ultrasound guided transvaginal drainage of abscesses in the small pelvis is usually performed using needles or stiff pig tail catheters without internal fixation. To prevent dislodgement during the subsequent drainage and irrigation procedure, we have developed a new soft 7 F balloon catheter for continuous transvaginal drainage. The catheter is made of soft C-flex and contains two channels, one for drainage and one for inflating a small distal balloon (outer diameter, 10 mm).