bluuebunny/crossref_metadata_2025 huggingface dataset:
Taking a Leap of Faith
Authors: Chan Kai Qin , Tong Eddie Mun Wai , Tan Yan Lin
Published: June 2014

Recent psychological models of religion suggest that religious beliefs provide a form of psychological control. Independently, other research has found that an increase in psychological control can lead people to adopt riskier strategies. Hence, we hypothesized that activation of God concepts increases risk taking. In three studies, we found that God primes led to take greater risk taking as though participants were literally “taking a leap of faith.” In Study 2, we presented evidence that this effect could be mediated by increased psychological control. Although consistent with psychological models of religion, the findings also contradict some survey findings that religious people are less risk seeking. This inconsistency was addressed in Study 3 by looking at how religion, morality, and risk taking are related. Implications to a relational schema approach to study the effects of God primes are discussed.
Who participates in communal violence? Survey evidence from South Africa
Authors: Claassen Christopher
Published: June 2014

Little is known about the thousands of people who take part in communal violence. Existing research is largely based on interviews, impressionistic accounts and government records of arrestees. In contrast, this paper examines data from a novel survey of a representative sample of residents of Alexandra, a township in South Africa where a 2008 nation-wide wave of anti-immigrant riots began. Data on participation in the attacks were collected using a method ensuring the privacy of responses, thus potentially reducing response bias. In contrast to the conclusions of existing research, which emphasize the participation of young males, the survey data reveal that a significant number of participants were female and participants were not particularly young, being 34 years old on average. Participants are more likely to support an opposition party, attend community policing meetings and have a high-school education.
Coupling effects on photoluminescence of exciton states in asymmetric quantum dot molecules
Authors: Fino Nelson R , Camacho Angela S , Ramírez Hanz Y
Published: June 2014

We present a theoretical study of photoluminescence from exciton states in InAs/GaAs asymmetric dot pairs, where interdot coupling is reached via magnetic field in the Faraday configuration. Electronic structure is obtained by finite element calculations, and Coulomb effects are included using a perturbative approach. According to our simulated spectra, bright excited states may become optically accessible at low temperatures in hybridization regimes where intermixing with the ground state is achieved. Our results show effective magnetic control on the energy, polarization and intensity of emitted light, and suggest these coupled nanostructures as relevant candidates for implementation of quantum optoelectronic devices.
ROS Are Critical for Endometrial Breakdown via NF-κB–COX-2 Signaling in a Female Mouse Menstrual-Like Model
Authors: Wu Bin , Chen Xihua , He Bin , Liu Shuyan , Li Yunfeng , Wang Qianxing , Gao Haijun , Wang Shufang , Liu Jianbing , Zhang Shucheng , Xu Xiangbo , Wang Jiedong
Published: June 2014

Progesterone withdrawal triggers endometrial breakdown and shedding during menstruation. Menstruation results from inflammatory responses; however, the role of reactive oxygen species (ROS) in menstruation remains unclear. In this study, we explored the role of ROS in endometrial breakdown and shedding. We found that ROS levels were significantly increased before endometrial breakdown in a mouse menstrual-like model. Vaginal smear inspection, morphology of uterine horns, and endometrial histology examination showed that a broad range of ROS scavengers significantly inhibited endometrial breakdown in this model. Furthermore, Western blot and immunohistochemical analysis showed that the intracellular translocation of p50 and p65 from the cytoplasm into the nucleus was blocked by ROS scavengers and real-time PCR showed that cyclooxygenase-2 (COX-2) mRNA expression was decreased by ROS scavengers. Similar changes also occurred in human stromal cells in vitro. Furthermore, Western blotting and real-time PCR showed that one ROS, hydrogen peroxide (H2O2), promoted translocation of p50 and p65 from the cytoplasm to the nucleus and increased COX-2 mRNA expression along with progesterone maintenance. The nuclear factor κB inhibitor MG132 reduced the occurrence of these changes in human stromal cells in vitro. Viewed as a whole, our results provide evidence that certain ROS are important for endometrial breakdown and shedding in a mouse menstrual-like model and function at least partially via nuclear factor-κB/COX-2 signaling. Similar changes observed in human stromal cells could also implicate ROS as important mediators of human menstruation.
On Optimal Retirement
Authors: Ernst Philip A. , Foster Dean P. , Shepp Larry A.
Published: June 2014

We pose an optimal control problem arising in a perhaps new model for retirement investing. Given a control function f and our current net worth X(t) for any t, we invest an amount f(X(t)) in the market. We need a fortune of M ‘superdollars’ to retire and want to retire as early as possible. We model our change in net worth over each infinitesimal time interval by the Itô process dX(t) = (1 + f(X(t)))dt + f(X(t))dW(t). We show how to choose the optimal f = f0 and show that the choice of f0 is optimal among all nonanticipative investment strategies, not just among Markovian ones.
Synchronization via Interacting Reinforcement
Authors: Dai Pra Paolo , Louis Pierre-Yves , Minelli Ida G.
Published: June 2014

We consider a system of urns of Pólya type, containing balls of two colors; the reinforcement of each urn depends on both the content of the urn and the average content of all urns. We show that the urns synchronize almost surely, in the sense that the fraction of balls of a given color converges almost surely as time tends to ∞ to the same limit for all urns. A normal approximation for a large number of urns is also obtained.
On the Asymmetric Telegraph Processes
Authors: López Oscar , Ratanov Nikita
Published: June 2014

We study the one-dimensional random motion X = X(t), t ≥ 0, which takes two different velocities with two different alternating intensities. The closed-form formulae for the density functions of X and for the moments of any order, as well as the distributions of the first passage times, are obtained. The limit behaviour of the moments is analysed under nonstandard Kac's scaling.
Introduction of the human AVPR1A gene significantly alters brain receptor expression patterns, and may enhance aspects of social behavior in transgenic mice
Authors: Charles Rhonda , Sakurai Takeshi , Takahashi Nagahide , Elder Gregory A. , Gama Sosa Miguel A. , Young Larry J. , Buxbaum Joseph D.
Published: June 2014

Central arginine vasopressin receptor 1A (AVPR1A) modulates a wide range of behaviors, including stress management and territorial aggression, as well as social bonding and recognition. Inter- and intra-species variations in AVPR1A brain expression patterns and downstream differential behavioural phenotypes have been attributed to differences in the 5′ non-coding region upstream of the AVPR1A gene including polymorphic elements within this regulatory area. Gene association studies have suggested a link between AVPR1A polymorphisms and autism and AVPR1A has emerged as a potential pharmacological target for treatment of social cognitive impairments and mood and anxiety disorders. To further investigate the genetic mechanism giving rise to species differences in AVPR1A expression patterns and associated social behaviors, and to create a preclinical mouse model useful for screening drugs targeting AVPR1A, we engineered and extensively characterized BAC transgenic mice harboring the entire human AVPR1A locus with the surrounding regulatory elements. Compared to wildtype animals, the humanized mice (hAVPR1A) displayed a more widely distributed AVPR1A binding pattern, with overlap with primate expression. Furthermore, hAVPR1A mice displayed increased reciprocal social interactions compared to wildtype animals, but no differences in social approach and preference for social novelty were observed. Aspects of learning and memory, specifically novel object recognition and spatial relocation recognition, were unaffected. The biological alterations in hAVPR1A mice resulted in the rescue of prepulse inhibition impairments observed in knockout mice, indicating conserved functionality. Although further behavioural paradigms and additional cohorts need to be examined in hAVPR1A mice, the results demonstrate that species-specific variations in the genomic content of regulatory regions surrounding the AVPR1A locus are likely responsible for differential receptor protein expression patterns across species and contribute to species-specific behavioral variation. The hAVPR1A mouse is a potential preclinical model for further understanding the regulation of receptor gene expression and the impact of variation in receptor expression on behaviors, and should be useful for screening drugs targeting human AVPR1A.
Cancers detected and induced in mammographic screening: new screening schedules and younger women with family history.
Authors: Law J
Published: June 2014

The numbers of cancers detected and induced in breast screening programmes are examined for two-view screening, and for a 2 year screening interval, in contrast to the single view screening at a 3 year interval of the UK Breast Screening Programme up until early 1995. Two-view screening is also considered for the 1 year interval and age range of the current UK age trial (40-47 years). The corresponding figures for screening of groups having a family history of breast cancer are calculated and discussed. Breast cancer induction data are taken from National Radiological Protection Board publications. Cancer detection rates are based on observed rates where available, and calculated rates otherwise. The results of calculations indicate cause for concern if screening is to be extended below the age of 30 years (or below 35 years in certain categories), or below 40 years of age if family history groups are shown in the future to have a generally increased susceptibility to ionizing radiation. The importance of restricting dose to 2 mGy per film (mean glandular dose for a standard breast thickness of 4.5 cm) is stressed, together with the need ot maintain maximum image quality. This is especially true for the family history groups, who should only be screened in centres within established screening programmes, or in centres with equally strict quality control procedures.
Mechanical thrombectomy of embolic occlusion in both the profunda femoris and superficial femoral arteries in critical limb ischaemia.
Authors: Rilinger N , Görich J , Scharrer-Pamler R , Vogel J , Tomczak R , Sokiranski R , Brambs H J
Published: June 2014

We report our preliminary experience using the Amplatz device for percutaneous thromboembolectomy in acute occlusion in both the profunda femoris artery (PFA) and superficial femoral artery (SFA) in four patients (mean age 78.5 years). All patients suffered from acute lower limb ischaemia, Fontaine Grade 3, due to cardiac embolization. Estimated occlusion times range from 3 h to 3 days. All four patients were treated successfully. Device activation time for both the PFA and the SFA was 85 s +/- 15 s. Total procedure time was 25 min +/- 10 min. There was no need for adjunctive procedures or intensive care monitoring. We conclude that the Amplatz device is a very effective and safe procedure for the quick restoration of vascular patency in cases of simultaneous embolically occluded PFA and SFA.
The incidence of transient renal medullary hyperechogenicity in neonatal ultrasound examination.
Authors: Howlett D C , Greenwood K L , Jarosz J M , MacDonald L M , Saunders A J
Published: June 2014

A prospective ultrasound study of the urinary tracts of 85 neonates (64 term, 21 preterm) was performed to assess the incidence of transient renal medullary hyperechogenicity (RMH) in the first week of life. None of the neonates examined had evidence of renal dysfunction. Echogenic material was observed in the renal papillae/calyces, ureter, or bladder of 33 of the 64 term babies, but in the bladder of only one pre-term infant. The distribution of the echogenicity differs from that seen in medullary hyperechogenicity due to crystal deposition, suggesting that calyceal involvement is a common feature. Follow-up ultrasound scans at 10-14 days were possible in eight of the term neonates and demonstrated complete resolution of the RMH. The aetiology of transient neonatal RMH is unclear, although it may be related to protein cast deposition in the renal tubules. RMH may rarely be associated with transient renal dysfunction, but in healthy neonates should be recognized as a normal variant.
Reproducibility of Leeds TOR(MAM) mammographic test object plates.
Authors: Underwood A C , Law J , Clayton C
Published: June 2014

Image quality test objects are essential tools for quality assurance in any branch of radiology. A major problem in test object construction is to make all examples of the test object closely comparable so that results from different examples can be compared. In mammography, the TOR(MAM) test object is considered to be the most sensitive of those generally available in the UK. This paper reports a comparison of 19 examples of this test object design, using five film scorers. Small differences in mean score were found to be statistically significant in about half of the test object plates tested. However, none of the plates differed from the overall mean at the 95% confidence level. Mean differences of score between single plates did not exceed 8%.
Training phantom for ultrasound guided biopsy.
Authors: Nicholson R A , Crofton M
Published: June 2014

Commercial phantoms designed for radiologists to practise the skills needed to biopsy lesions under ultrasound guidance can be prohibitively costly, and do not have an indefinite shelf-life. A gelatin-based in-house model has been developed to recreate the conditions found in human tissues, using materials which are cheap and in everyday use. This phantom remains useful for several weeks, although tears produced by the biopsy needle take progressively longer to bond when the reconstructed gelatin is older than a month. However, new phantoms can be built quickly and easily using fresh gelatin while recycling other components.
MRI in primary non-Hodgkin's lymphoma of the vagina associated with a uterine congenital anomaly.
Authors: Jenkins N , Husband J , Sellars N , Gore M
Published: June 2014

This case report describes the MRI features of untreated primary lymphoma of the vagina associated with a congenital septate uterus. The information provided by MRI was superior to CT in defining the extent of tumour invasion. MRI also detected a previously undiagnosed congenital anomaly.
The natural history of the multicystic dysplastic kidney in children.
Authors: Rottenberg G T , Gordon I , De Bruyn R
Published: June 2014

The objective of this study was to examine the natural history of the multicystic dysplastic kidney and the use of sonography for follow-up studies. A retrospective study was performed on 66 children with a radiological diagnosis of multicystic kidney. The change in size demonstrated on sonograms was examined. Adequate follow-up was available on 55 children over a period of 32 months (range 2-69 months). 40/55 of the kidneys underwent a reduction in size, including 22 which were no longer detectable by ultrasound. 10/55 kidneys showed an increase in size and 5/55 showed no change. Reduction in size occurred at a mean age of 84 weeks (range 20-120 weeks). In conclusion, most multicystic kidneys undergo partial or complete involution over the first 2 years of life. The mean size of the multicystic kidney at diagnosis is a poor predictor of eventual outcome.
Elevated trace element concentrations in malignant breast tissues.
Authors: Ng K H , Bradley D A , Looi L M
Published: June 2014

In vitro neutron activation analysis (NAA) was performed on malignant and adjacent normal tissue from 46 human female breast tumours. The objective was to investigate the chemical environment of the tissues within which microcalcifications develop and to develop a method for discrimination between malignant and normal breast tissue. The elements Al, Br, Ca, Cl, Co, Cs, Fe, K, Mn, Na, Rb and Zn were significantly higher in the cancer tissues (all p < 0.001; except for Co, p < 0.003, Wilcoxon signed-ranks test). In addition, a significant correlation (0.80, Spearman rank correlation) was found for Rb and Zn in tumour tissues. Present results are supported by the findings of others. The relevance of elevated concentrations of these elements in cancer breast tissue remains a matter of conjecture. Evidence suggests that there is a connection both with increased cellular activity and blood supply and the formation of microcalcifications in malignant breast tissues. This study suggests an association between the elemental composition of breast tissues and the formation of breast particles. That is, elevations of elemental concentration and clustered calcifications in breast are possibly related.
MRI of inner ear anatomy using 3D MP-RAGE and 3D CISS sequences.
Authors: Held P , Fellner C , Fellner F , Seitz J , Strutz J
Published: June 2014

The aim of this study was to compare contrast enhanced 3D MP-RAGE (magnetization prepared rapid gradient echo), unenhanced 3D MP-RAGE and 3D CISS (constructive interference in steady state) in the evaluation of anatomical detail of the inner ear and facial nerve. 60 persons with no abnormalities and no or non-specific symptoms were examined with MRI. All examinations were performed using a 1.5 T MR unit. The detectability of anatomical details was evaluated by agreement of three radiologists. Statistical evaluation of the results was achieved by the two-tailed Wilcoxon's test. In 86-95% of the cases, 3D CISS resulted in excellent visibility of the basal and second turn and apex of the cochlea, the vestibule and semicircular canals, as well as the nerves within the internal auditory canal. There was a significantly better visualization with CISS than with MP-RAGE. Detectability of the extrameatal facial nerve was best using contrast enhanced 3D MP-RAGE in 91-96% of the cases (labyrinthine segment 96.7%; geniculate ganglion 95%; tympanic segment 91.7%; vertical segment 95%). The detection of the meatal seventh nerve was best using CISS, whilst unenhanced MP-RAGE gave significantly better results than contrast enhanced MP-RAGE. These results suggest that unenhanced and contrast enhanced 3D MP-RAGE and 3D CISS sequences are complementary and not alternative MRI techniques. Both T1 and T2 weighted 3D MR imaging of the temporal bone is of advantage when compared with 2D MR sequences due to improved contrast, geometrical resolution and the possibility of adequate reconstruction of anatomical structures.
Radiotherapy in the treatment of solitary plasmacytoma.
Authors: Jyothirmayi R , Gangadharan V P , Nair M K , Rajan B
Published: June 2014

Solitary plasmacytoma of bone (SPB) and extramedullary plasmacytoma (EMP) are rare. High local control rates are reported with radiotherapy, although the optimal dose and extent of radiotherapy portals remains controversial. Between 1983 and 1993, 30 patients with solitary plasmacytoma were seen at the Regional Cancer Centre, Trivandrum, India. 23 patients had SPB and seven EMP. The mean age was 52 years and the male to female ratio 3.2:1. Diagnosis of SPB was confirmed by biopsy in 16 patients and tumour excision in seven. 20 patients received megavoltage radiotherapy to the bone lesion with limited margins, and one received chemotherapy. Two patients who underwent complete tumour excision received no further treatment. All seven patients with EMP received megavoltage radiotherapy, four following biopsy and three after tumour excision. Local control was achieved in all patients with SPB. Nine progressed to multiple myeloma and one developed a solitary plasmacytoma in another bone. Six patients with EMP achieved local control. Three later progressed to multiple myeloma and one had local relapse. Median time to relapse was 28 months in SPB and 30 months in EMP. 5-year overall survival rates were 82% and 57% for patients with SPB and EMP, respectively. The corresponding progression free survival rates were 55% and 50%, respectively. Age, sex, site of tumour, serum M protein and haemoglobin levels did not significantly influence progression free survival. The extent of surgery, radiotherapy dose or time to relapse were not significant prognostic factors. Radiotherapy appears to be an effective modality of treatment of solitary plasmacytoma. No dose-response relationship is observed, and high local control rates are achieved with limited portals. Progression to multiple myeloma is the commonest pattern of failure, although no prognostic factors for progression are identified. The role of chemotherapy in preventing disease progression needs further evaluation.
Assessing the degree of osteoporosis in the axial skeleton using the dependence of the fractal dimension on the grey level threshold.
Authors: Haidekker M A , Andresen R , Evertsz C J , Banzer D , Peitgen H O
Published: June 2014

Combining the measurement of bone mineral density (BMD) and the classification of the trabecular structure in cancellous bone improves the estimation of the degree of osteoporosis. A fractal method for the automatic quantitative classification of the trabecular structure in midvertebral slices of lumbar vertebrae is introduced. This method is based on the computation of the fractal dimension (box counting method) for varying binarization thresholds. Radiographic images from 30 lumbar vertebrae and CT images from an additional 16 lumbar vertebrae were analysed by calculating the dimension D in dependency of the threshold value T. The function D(T) was normalized by the average image grey value, eliminating the bone mineral density from the computations. The results show that the images of the lumbar vertebrae have fractal properties, and the function D(T) has a typical behaviour that allows the discrimination of the degree of osteoporosis. With two parameters extracted from the function D(T) the correlation coefficients with BMD were both -79% for the radiographic images, and -93% and -91% for the CT data, respectively.
Segmental arterial mediolysis studied by repeated angiography.
Authors: Sakano T , Morita K , Imaki M , Ueno H
Published: June 2014

Segmental arterial mediolysis (SAM) is a rare disease of unknown aetiology. We report the fourteenth case of SAM, but the first to demonstrate serial changes on arteriography. A 65-year-old woman with abdominal pain underwent laparotomy with resection of an abnormally beaded and narrowed segment of the right branch of the middle colic artery. Characteristic pathological findings of lysis of the arterial media with dissecting haematomas were present. Other than some post-prandial pain, the patient's post-operative course was uneventful. Serial arteriography showed various abnormalities in the trunk and branches of the superior mesenteric artery. Changes in the vessels consisted of three phases, i.e. dilatation, beading with narrowing and restoration of the smooth wall, with various modifications such as aneurysmal enlargement and occlusion.
Risk assessment of the nuclear medicine patient.
Authors: Mountford P J
Published: June 2014

Two types of risk are identified following the administration of a radiopharmaceutical to a patient: the risk to the patient, and the risk to critical groups exposed to the patient. The method for quantifying the risk to the patient is described in terms of estimating the effective dose. The main limitations in these estimates for adult and paediatric patients are uncertainties in the biokinetic data, and the assumption of a uniform distribution of activity in each organ. Effective doses from most nuclear medicine procedures will not exceed twice the annual dose from natural background radiation in the UK. Lack of human placental transfer data is now the main limitation to estimating fetal doses. The characteristics of two methods which can be used to derive the dose to critical groups exposed to nuclear medicine patients are reviewed. It is shown that studies using either method have indicated that the current recommendations in the UK for restricting the exposure of these groups and the recommendation recently proposed for restricting the exposure of pregnant members of staff are not appropriate. Revised recommendations for restricting the behaviour of patients administered iodine-131 should await the results of a current multicentre trial. The method to estimate the dose to a breast-fed infant from a mother administered a radiopharmaceutical is outlined, and the recently revised guidance for interrupting breast feeding is summarised. When a recommendation for controlling risk is to be derived from dosimetry data obtained from a number of individuals, an outstanding issue to be resolved is the value (e.g. 95% upper confidence limit) on which it should be based.
In vivo demonstration of microcalcification in breast cancer using high resolution ultrasound.
Authors: Yang W T , Suen M , Ahuja A , Metreweli C
Published: June 2014

84 patients with 89 primary breast cancers underwent high resolution ultrasound, mammography and histological evaluation. Pathological specimens and hard copy images of both imaging modalities were reviewed in order to document the amount of microcalcification present in each tumour. A total of 44, 40 and 46 tumours had visible microcalcification using high resolution ultrasound, mammography and histology, respectively. Using mammography as the gold standard, ultrasound achieved a sensitivity of 95%, specificity of 87.8% and accuracy of 91% in the detection of microcalcification. Histology had a sensitivity of 80%, specificity of 71.4% and accuracy of 75.3%. We conclude that ultrasound is sensitive in the detection of microcalcification in breast cancer when they are within a mass lesion, and is a reliable diagnostic sign of carcinoma when present.
Pre-operative TN staging of gastric cancer using a 15 MHz ultrasound miniprobe.
Authors: Akahoshi K , Chijiiwa Y , Sasaki I , Hamada S , Iwakiri Y , Nawata H , Kabemura T
Published: June 2014

The aim of the study was to evaluate the usefulness of and problems associated with a new endoscopically guided ultrasound miniprobe, used for pre-operative staging of gastric cancers. 59 cases of gastric cancer were prospectively examined with a 15 MHz ultrasound miniprobe. The results of the ultrasound imaging were compared with the histological findings of the resected specimens. The accuracy of the miniprobe for depth of invasion (T category) was 61% for all tumours, and 72% and 40%, respectively, for T1 and T2 to T4 lesions. If indeterminate cases due to ultrasound attenuation were excluded, the accuracy was improved to 82% for T1 and 57% for T2 to T4 tumours, respectively. The accuracy of the miniprobe for nodal staging (N category) was 69% overall, and 86%, 25% and 14% for stages N0, N1 and N2, respectively. In tumours classified on the basis of endoscopic types, the miniprobe staged early type gastric cancers (T category = 73%, N category = 80%) significantly (p < 0.01) more accurately than advanced ones (T category = 21%, N category = 36%). This study suggests that the miniprobe is indicated for pre-operative TN staging when endoscopy reveals an early gastric cancer.
Prenatal diagnosis of an extensive fetal lymphangioma using ultrasonography, magnetic resonance imaging and cytology.
Authors: Kaminopetros P , Jauniaux E , Kane P , Weston M , Nicolaides K H , Campbell D J
Published: June 2014

An unusual case of fetal lymphangioma diagnosed before delivery is reported in a second trimester pregnant woman. The lymphangioma was suspected at 28 weeks on the basis of the ultrasound appearances and progression of the lesions with advancing gestation. MRI was used to evaluate the extent and the tissue characteristics of the lesions. Cytology of the fluid aspirated from the cystic lesions showed abundant lymphocytes and macrophages, confirming the diagnosis of a lymphangioma. The parents opted for a pregnancy termination because of the rapid growth of the lesions and the poor prognosis. It is suggested that the combination of these tests could enable the early diagnosis of these tumours at a stage when the lesion is relatively limited and accessible to therapy in utero.
Optimum conditions for iron colloid enhanced fast spin echo imaging in hepatocellular carcinoma.
Authors: Sugihara S , Suto Y , Yoshida K
Published: June 2014

The optimum conditions for iron colloid enhanced fast spin echo (FSE) in the detection of hepatocellular carcinoma have not been clearly established as yet. MRI was performed on 14 patients with hepatocellular carcinoma (45 nodules) before and after administration of chondroitin sulphate iron colloid (CSIC). One type of conventional spin echo (CSE) (TR/TE = 1800/80) was then quantitatively and qualitatively compared with three types of FSE (FSE 1800 (TR/effective TE/echo factor = 1800/90/7); FSE 7 (3500/90/7); and FSE 11 (3500/99/11)). The liver signal-to-noise ratio (SNR) was significantly decreased after CSIC administration in all sequences, while the tumour-to-liver contrast-to-noise ratio (CNR) was significantly increased. Although the decreased ratio of the liver SNR was smaller on the three FSE sequences compared with CSE, the increased ratio of the tumour-to-liver CNR was higher on the FSE sequences. The highest increase of the tumour-to-liver CNR was on the FSE 7 sequence. The number of detectable tumours, both before and after the administration of CSIC, was largest on FSE 7. In conclusion, FSE with longer TR and TE, and decreased echo factor, was especially useful for CSIC enhanced liver MRI.
Transient small bowel intussusception: CT findings in adults.
Authors: Catalano O
Published: June 2014

Transient non-obstructing intussusception is known to occur in adults. While the CT findings in small bowel intussusception have been described in detail, few reports concerning transient cases have been published. We evaluated five patients with non-obstructive jejuno-jejunal invagination. All CT studies showed a target pattern with an intraluminal soft tissue mass, an eccentric mesentery, and a slightly dilated intussuscipiens. Transient intussusception has typical CT features and should be distinguished from more severe forms requiring prompt surgical treatment.
Evaluation of quantitative CT vertebral bone mineral density measurement and the Singh index in elderly females with hip fractures--a case control study.
Authors: Heneghan J P , Kirke P N , Murphy B L , Darcy E , Daly L , Bourke G J , Dinn E , Masterson J
Published: June 2014

This study aims to evaluate the ability of quantitative computed tomography (QCT) bone mineral density (BMD) measurement of vertebral bodies to predict risk of hip fracture. We also examine the predictive value of the radiographic Singh index and its relationship to the vertebral BMD. The vertebral BMD (using a QCT protocol) and radiographic Singh index were evaluated in 86 white females who had sustained a hip fracture after minor trauma. 86 age-matched female controls were also studied. All patients were post-menopausal, the age range was 52-95 years. BMD values were found to be low in both the study group and controls; there was no statistically significant difference between the groups. A low Singh index did not correlate with hip fracture, nor did it correlate with low vertebral BMD measurement. We conclude that vertebral BMD and radiographic Singh index are not reliable predictors of hip fracture in the elderly female.
Measurement of radiation dose received by the hands and thyroid of staff performing gridless fluoroscopic procedures in children.
Authors: Coakley K S , Ratcliffe J , Masel J
Published: June 2014

The aim of this study was to confirm that the radiation doses received by attendants who manually restrain infants during fluoroscopic procedures are low. Doses to the hands and neck of three radiologists and three nurses performing or assisting at all the fluoroscopic procedures in a children's hospital were measured for 1 month using thermoluminescent dosemeters. All fluoroscopy on children at this hospital is performed without an antiscatter grid. Total doses for the neck ranged from 20 to 50 microSv per week and for hands from 40 to 210 microSv per week. These doses were shared by the three radiologists and the three nurses. Individual doses received per staff member are very small when compared with the doses received by interventional radiology staff. Doses received by staff in this study were of the order of 5% of the limit advised by the National Health and Medical Research Council of Australia (NHMRC) for radiation workers. Nurses received larger doses than radiologists and steps will be taken to reduce this dose further.
Atypical angiographic appearance of a superficial femoral artery mycotic aneurysm.
Authors: Fung Y , Ahn J , Stancato-Pasik A , Rybak L D , Mitty H A , Cooper J M , Silberzweig J E
Published: June 2014

An unusual presentation of mycotic aneurysm is described. In this case, a large thrombosed mycotic aneurysm of the superficial femoral artery was associated with segmental occlusion of the adjacent artery. Small vessels were delineated in the periphery of the aneurysm on angiography.
The changing face of emphysematous cholecystitis.
Authors: Gill K S , Chapman A H , Weston M J
Published: June 2014

Emphysematous cholecystitis is a variant of acute cholecystitis characterized by the presence of gas in the gall bladder lumen, wall or pericholecystic tissues in the absence of an abnormal communication between the biliary system and the gastrointestinal tract. In the past, the diagnosis has relied on the plain abdominal radiograph (AXR), since there are no clinical features to separate this condition from simple acute cholecystitis. The apparently high mortality and morbidity associated with emphysematous cholecystitis has previously emphasized the importance of emergency cholecystectomy. We have reviewed eight cases of emphysematous cholecystitis presenting to this hospital over the last 5 years. The diagnosis was made on AXR in only one of these cases. Ultrasound (US) scans were performed in all eight cases, of which five were positive and three negative, due to non-visualization of the gall bladder. In the three negative cases, the diagnosis was made on subsequent CT scans. On initial clinical examination, only one of the eight patients appeared systemically unwell and conservative management was employed in five of the patients. The remaining three patients underwent cholecystectomy within 3-5 days because of continuing signs or symptoms. It is concluded that the AXR is relatively insensitive in the diagnosis of emphysematous cholecystitis. As a result of the regular use of US in suspected hepatobiliary disease, emphysematous cholecystitis is being diagnosed with increased frequency, uncovering a broad spectrum of disease ranging from mild to severe. Previously, failure to separate milder cases from simple acute cholecystitis may have been responsible for reports of unremitting severity and progression requiring emergency cholecystectomy. Based on clinical assessment, conservative surgical management is possible in a significant proportion of patients.
A comparison of the effectiveness of 28 kV (grid) versus 25 kV (no grid) mammographic techniques for breast screening.
Authors: Warren R M , Duffy S
Published: June 2014

The purpose of this study was to compare the clinical effectiveness of breast screening using a mammographic technique of 25 kV without a grid, with one of 28 kV with a grid. Effectiveness is judged by cancer detection, interval cancer rates, sensitivity and specificity calculations and tumour characteristics. The doses on standard physics tests given by the three machines when these exposure factors are selected were compared to see whether there is any scientific basis for recommendations on which is the more effective technique. The experiment was undertaken in the prevalence round of a screening programme set up in the UK in 1987. The main comparison is on 25,078 women randomized to one or other technique after March 1989. Comparison can also be made with the preceding 8482 women, who were examined by the 25 kV method, but not randomized and in whom there were a variety of other differences. In the randomized group there was no statistically significant difference in cancer detection. A minor difference in overall numbers without statistical significance was seen in favour of the 28 kV grid technique, but is offset by a greater interval cancer rate in this group. Small cancer detection was equal in the two groups. By contrast, the first 8482 women showed significantly worse screening performance, both in lower overall and small cancer detection rate, and in increased number of interval cancers, for which the explanation is likely to be complex. The dose measurements show that the use of a higher tube potential with the grid mitigates the dose increase that may have been expected. The choice between these two techniques is therefore neither automatically made by greater cancer detection nor made on grounds of dose. There was a minor dose penalty in using the 28 kV technique with grid.
The agreement between colour Doppler systems in measuring internal carotid artery peak systolic velocities.
Authors: Wolstenhulme S , Evans J A , Weston M J
Published: June 2014

The study was undertaken to determine if the internal carotid artery peak systolic velocities (ICA PSVs) measured by two colour Doppler imaging systems (Acuson 128 and Siemens Quantum) agree sufficiently for the two systems to be interchangeable in evaluating carotid artery disease. One operator obtained blinded measurements of ICA PSV in 63 prospective nonrandomized patients at risk of stroke. The operator examined 20 patients in the first cohort to assess the intraobserver variation, and 43 patients in the second cohort to assess the limits of agreement between the systems. In vitro comparisons of the systems were also undertaken, using both string and flow phantoms. Excluding one outlier, the intraobserver reproducibility coefficient for both machines was 0.48 m s-1. The limits of agreement (within which 95% of differences lie) between systems were -0.47 to 0.45 m s-1. This reduced to -0.39 to 0.33 m s-1 when the one outlier was excluded. This is within the intraobserver reproducibility range. In vitro data show little intersystem variation with phantom velocity. Intratransducer differences increase when the Doppler angle is increased using the string phantom; maximum differences: Acuson 0.30 m s-1 (42%) and Siemens 0.32 m s-1 (32%). These are within the in vivo reproducibility range. Intratransducer difference decreases when the Doppler angle is increased using the flow phantom, maximum differences: Acuson 0.05 m s-1 and Siemens 0.07 m s-1. The results show the systems agree sufficiently to be interchangeable in evaluating carotid artery disease; however, errors in maximum PSVs, caused by operator or system variation, may lead to errors in percent stenosis grading of the carotid arteries.
Ultrasound diagnosis of metastatic melanoma of the gallbladder.
Authors: Holloway B J , King D M
Published: June 2014

The abdominal ultrasound examinations of 464 patients with malignant melanoma performed over a 3 year period were reviewed. 23 (5.2%) had soft tissue material attached to the gallbladder wall and projecting into the lumen. Four of these were polyps of less than 1 cm which were thought to be benign, while the remaining 19 had abnormalities likely to be metastatic melanoma. Upper abdominal ultrasound examinations are frequently requested for staging purposes in patients with thick high grade malignant melanoma or clinical suspicion of metastases. Ultrasound clearly identifies the gallbladder and biliary tree in the vast majority of patients and is generally regarded as the imaging modality of choice for suspected gallbladder pathology. As autopsy studies have confirmed the incidence of gallbladder metastases from malignant melanoma to be 15-20%, a careful review of the gallbladder is advocated when abdominal ultrasound examinations are performed on patients with malignant melanoma.
Magnetic resonance imaging of subcutaneous diffuse neurofibroma.
Authors: Peh W C , Shek T W , Yip D K
Published: June 2014

A 31-year-old woman presented with increasing pain and tenderness of a long-standing soft tissue mass on her back. MRI showed a network of interconnecting tubular areas, which were T1 isointense and T2 hyperintense relative to skeletal muscle, and displayed marked Gd-DTPA enhancement. The lesion was situated within the subcutaneous fat. Clinically and radiologically, this mass was considered to be a subcutaneous venous haemangioma. Histological examination of the excised mass showed a diffuse neurofibroma with ectatic vessels and entrapped adipose tissue. Similar MRI appearances of subcutaneous haemangioma and diffuse neurofibroma may result in failure to make the correct diagnosis and in inappropriate management.
A philosophical approach to treatment machine maintenance and breakdown.
Authors: Colligan S J , Mills J A
Published: June 2014

Planned preventative maintenance (PPM), quality control (QC) checks and breakdown all contribute to the down-time of a radiotherapy treatment machine. Low levels of machine availability are unacceptable both clinically and financially. Clinical data demonstrate that, for many tumours, interruptions to treatment will result in reduced local control. Reductions to the gaps in treatment can be achieved by patient interchange between machines. Maintaining the maximum possible machine availability will reduce the potential for errors associated with the transfer of patients between machines, and reduce the cost of treatment. Practices for routine PPM and QC vary between hospitals. In this report, a rationale for breakdown and maintenance will be described. Based on the faults experienced on a Philips SL 75-5 and a Philips SL25 over a period of 3 years, the workload associated with routine maintenance and quality control are presented and the additional work associated with breakdown discussed. Faults have been categorized on a scale between catastrophe and maintainability. A demonstration of how this analysis can be used to assess the cost-benefits of proposed changes in working patterns by the extension or reduction of maintenance periods is provided. The results indicated that no gain would be made in changing from a 1-day to a 2-day per month PPM schedule.
An evaluation of correction factors applied to dose-area product meter readings for the use of sinus cones.
Authors: Bridge L R , Ison J E
Published: June 2014

As a result of the refurbishment of a dedicated skull radiography unit (Siemens Orbix) a dose-area product (DAP) meter was fitted into the light beam diaphragm/X-ray collimating system. Following calibration of the DAP system for X-ray beams defined by the unit's integral rectangular and octagonal iris diaphragms, DAP correction factors were obtained for the clinical use of externally fitted sinus cones. Correction factors can be derived from a simple ratio of coned to unconed beam areas, and these agree well with measured correction factors. The simple ratio of areas factor may be used in clinical practice to reduce potential errors.
The magic angle phenomenon in tendons: effect of varying the MR echo time.
Authors: Peh W C , Chan J H
Published: June 2014

Increased signal intensity on magnetic resonance (MR) imaging of tendons arising from the magic angle phenomenon is well recognized. This study aimed to evaluate the effect of varying the echo time (TE) upon tendon signal intensity, and to determine if a modified TE value produces acceptable T1 and proton density (PD) weighted images. Fresh bovine tendons were imaged in a 1.5 T MR scanner using spin echo (SE) T1 and PD weighted sequences and utilizing a number of different coils. For each set of sequences, the tendon was orientated at 55 degrees to the main magnetic field (B0) and imaged using constant TR and incremental TE values. Signal intensity was measured on images at each TR/TE value and compared with the signal intensities of tendons orientated at 0 degree to B0, obtained using minimum TE values. This experiment was repeated with a 1.0 T MR scanner and utilizing a spine coil. The Achilles tendon of a human volunteer was similarly imaged using a general purpose flex coil. For bovine and human tendons orientated at 55 degrees to B0, the signal intensities decreased exponentially with increasing TE. A critical TE value exceeding 37 ms, for each sequence, reduced the signal intensities to the levels obtained with the tendons orientated at 0 degree to B0, such that the magic angle phenomenon could be avoided. Although there was variability of the signal intensities with different coils, the critical TE value remained constant and the anatomical clarity was not degraded. The critical TE value was unaltered using two MR scanners of different field strengths.
A simple method for investigating the effects of non-uniformity of radiofrequency transmission and radiofrequency reception in MRI.
Authors: Barker G J , Simmons A , Arridge S R , Tofts P S
Published: June 2014

Inhomogeneity of the transmitted or received B1 field leads to intensity variations in MR images and spatial dependence in apparent concentration in MR spectra. We describe a simple method for investigating such variations. The transmitted B1 field can be measured both in vivo and in vitro which allows investigation of sample dependent effects that can not be measured on phantoms. For homogeneous regions the method also allows the received B1 field to be measured both in vivo and in vitro. Our method uses only a standard spin echo pulse sequence and simple region of interest analysis and should be implementable on any commercial scanner. The method is demonstrated using a variety of transmission and reception radiofrequency coils both in vivo and in vitro.
Thymic sarcoma in childhood.
Authors: Iyer R , Jaffe N , Ayala A G , Eftekhari F
Published: June 2014

Sarcoma of the thymus is exceedingly rare, especially in children. We report a case of thymic sarcoma in a child, including the imaging findings which have not been previously described.
Recurrent follicular carcinoma-oxyphilic cell type (Hürthle cell carcinoma) of the thyroid, imaging with iodine-131 and technetium-99m tetrofosmin before and after radiotherapy.
Authors: Bomanji J B , Gacinovic S , Gaze M N , Costa D C , Ell P J
Published: June 2014

A 68-year-old male with recurrence of malignant follicular carcinoma-oxyphilic cell type of the thyroid after surgery underwent whole body scintigraphy with 131I-sodium iodide and 99Tcm-tetrofosmin (Myoview). 131I scanning demonstrated local uptake most likely to be in the normal remnant, but 99Tcm-Myoview images delineated recurrence of the carcinoma in the neck, with more extensive involvement. We believe that a combination of 131I and 99Tcm-tetrofosmin imaging may be useful to assess the extent of disease in patients with recurrent Hürthle cell type carcinoma of the thyroid.