bluuebunny/crossref_metadata_2025 huggingface dataset:
Radiation protection awareness in non-radiologists.
Authors: Quinn A D , Taylor C G , Sabharwal T , Sikdar T
Published: June 2014

The outcome of teaching the core of knowledge to clinicians and the impact of the POPUMET regulations was assessed using an anonymous questionnaire. 82 of 120 (76%) of non-radiologists responded, of these 37% had attended a radiation protection course. Course attendance improved knowledge of the existence of the POPUMET regulations (p < 0.0001) and the ALARA principle. Course attendance made no difference to knowledge of the relative radiation dose of various radiological procedures. An underestimation of radiation dose was made by all responders (p < 0.001). The majority of responders were not aware that patients have no annual dose limit and the majority did not know the relative radiosensitivity of different organs. We have shown that despite the POPUMET regulations the majority of clinicians have not received adequate radiation protection teaching and that even if a course has been attended overall knowledge is still poor. We propose that formal compulsory teaching at undergraduate level may correct this in the future.
MRI study of hepatic tumours following high intensity focused ultrasound surgery.
Authors: Rowland I J , Rivens I , Chen L , Lebozer C H , Collins D J , ter Haar G R , Leach M O
Published: June 2014

High intensity, focused ultrasound has considerable potential as a non-invasive surgical technique, with applications which include the treatment of benign prostatic hyperplasia and the elimination of metastatic disease in the liver. In this study, the use of MRI for treatment planning and subsequent monitoring of ultrasound therapy in the liver has been evaluated. In an experimental model both tumour bearing and normal liver lobes were treated invasively with high intensity focused beam ultrasound surgery. Subsequent changes in the tissue properties were investigated using MRI, in combination with the intravenous contrast agent, Gd-DTPA. The repair of ultrasound damaged tissue was followed until 8 weeks after treatment. The appearance of the MR images was compared with histological sections prepared from parallel experiments. Imaging and histology results showed excellent agreement, illustrating that MRI is well suited to the non-invasive observation of the effects of high intensity focused ultrasound therapy on tissue. Thus, as the clinical potential of ultrasound surgery is realized, MRI, together with the use of contrast agents, will be invaluable both in treatment planning and in monitoring the progress of a treated tumour.
Effect of radiographic contrast media on endothelium derived nitric oxide-dependent renal vasodilatation.
Authors: Morcos S K , Oldroyd S , Haylor J
Published: June 2014

The effect of diatrizoate (Urografin325) on the cumulative dose-response curve of the vasodilatory response to acetylcholine was studied in the isolated perfused rat kidney (IPRK). The effect of 1-nitroarginine methyl ester (L-NAME) (10 mumol l-1) on the cumulative concentration-response curve of the vasodilatory response to acetylcholine and sodium nitroprusside was also studied. Acetylcholine is a vasodilator dependent on nitric oxide (NO) synthesis by the endothelium; sodium nitroprusside is a vasodilator not dependent on endogenous NO synthesis and L-NAME is an inhibitor of endogenous NO synthesis. The effect of L-NAME (10 mumol l-1) on the vasodilatory effect of diatrizoate which is observed in the presence of endothelin A receptor antagonist (BQ123, 10 mumol l-1) was also studied. In all experiments an infusion of angiotensin II (5 ng min-1) was maintained to increase the vascular tone of the preparation. Acetylcholine induced vasodilatation and the maximum increase in renal perfusate flow (RPF) was 17.0 +/- 1.7%, (p < 0.05). Diatrizoate (20 mgl ml-1 perfusate concentration) which induced a sustained fall in the RPF (-31.0 +/- 1.7%, p < 0.05) had no effect on the vasodilatory response to acetylcholine, and a similar increase in the RPF (17.8 +/- 2.2%, p < 0.05) was observed. In contrast, L-NAME (10 mumol l-1) completely abolished the vasodilatory effect of acetylcholine and produced instead a modest decrease in RPF by -5.0 +/- 1.7% (p < 0.05). The vasodilatory effect of sodium nitroprusside was not affected by L-NAME, confirming its selectivity as an inhibitor of endogenous NO synthesis in the IPRK. The maximum increase in the RPF induced by sodium nitroprusside was 23.1 +/- 2.0% (p < 0.05) in the absence of L-NAME and 21.2 +/- 2.2% (p < 0.05) in its presence. L-NAME did not interfere with the vasodilatation induced by diatrizoate in the presence of BQ123. In the presence of BQ123 alone the RPF increased from 23.3 +/- 1.4 ml min-1 g-1 to 26.5 +/- 1.0 ml min-1 g-1 (p < 0.05). In the presence of L-NAME and BQ123 the RPF increased from 24.4 +/- 3.0 ml min-1 g-1 to 27.2 +/- 2.7 ml min-1 g-1 (p < 0.05). There was no difference between the two groups (p > 0.05). In conclusion, diatrizoate did not interfere with endothelium derived NO-dependent vasodilatation in the kidney. A reduced production of NO in the vascular endothelium induced by contrast media is unlikely to play any role in the pathophysiology of the increase in renal vascular resistance produced by these agents. The renal vasodilatation induced by diatrizoate is not dependent on endogenous production of NO.
Does 100 mm photofluorography always have a dose advantage over conventional film-screen radiography in barium meals?
Authors: Dzik-Jurasz A S , Mumcuoglu E A
Published: June 2014

It is generally held that 100 mm photofluorography has a significant dose saving advantage over conventional radiography. The dose area product (DAP) data for the two formats were available for study in consecutive patients undergoing barium meal examination. There was no significant difference in DAP readings between the two formats. Conventional radiographs expose a 40% greater area than the 100 mm format, probably accounting for the lower mean DAP value of photofluorography. The mean DAP for whole examinations was 26.1 Gy cm2 for photofluorography, and 30.5 Gy cm2 for conventional radiography. These are both above the third quartile of national reference dose levels. There is little apparent difference in the doses incurred by patients between the two formats in respect of the working practice of the department. Barium meals will therefore continue to be recorded on both formats.
Absorbed dose measurements in dual energy X-ray absorptiometry (DXA).
Authors: Bezakova E , Collins P J , Beddoe A H
Published: June 2014

In this study a predominantly film dosimetric method was used to measure the effective dose from posteroanterior (PA) lumbar spine and proximal femur scans performed on a Lunar DPX-L machine. Because of the very low dose rate in scanning mode, the depth dose data were determined using a stationary detector configuration. The characteristic curve for the film (Kodak TMAT-H) was obtained and depth dose measurements were made using slabs of "solid water". The film was calibrated using a superficial X-ray unit (calibrated against a standard traceable to a national standard). To assess the change in film response with beam hardening at depth, the film was exposed to calibration beams of different half value layer (HVL). The HVL of the DXA beam was determined for surface and depth doses using aluminium filters and a diamond detector (an energy independent device). All measurements were performed three times. Beam size was measured using film, and the scan areas and times were determined by scanning phantoms. The dose from a scan was calculated using Dsc = DTscAb/Asc, where D = dose rate (stationary), Tsc = scan time, Ab = beam area, and Asc = scan area. Organ doses were determined using an anatomical atlas and ICRP 23 female reference. All film measurements had good precision (coefficient of variation < 4%). There was little variation in film sensitivity with change in HVL (< 1% change for the first three HVLs) and consequently no corrections were applied to the depth dose data. Skin entrance dose was 11.5 microGy. Effective dose in females was 0.19 microSv for the PA lumbar spine. For the proximal femur scan, the effective dose was 0.14 microSv (ovaries included) and 0.023 microSv (ovaries excluded) for pre-menopausal and pos-menopausal women, respectively.
Neonatal thymic haemorrhage.
Authors: Bees N R , Richards S W , Fearne C , Drake D P , Dicks-Mireaux C
Published: June 2014

Thymic haemorrhage in a neonate is an exceedingly rare condition. A case is presented of a neonate presenting at birth with cyanosis, respiratory distress and an anterior mediastinal mass. The radiological findings are demonstrated. After surgical excision and histopathological examination the lesion was found to be spontaneous haemorrhage into normal thymic tissue. Spontaneous thymic haemorrhage should be considered in any neonate developing acute respiratory distress with widening of the mediastinum and pleural effusion on chest radiography. Ultrasound may be used to support the diagnosis.
High attenuation lymphadenopathy caused by amyloidosis.
Authors: Fukuda T , Takao M , Uchida T , Iwanaga S , Hayashi K , Okimoto T
Published: June 2014

We describe a patient with generalized lymphadenopathy due to amyloidosis which showed on computed tomography as masses with high attenuation. Haemorrhage within lymph nodes caused by vascular amyloid deposition was confirmed at autopsy.
Osteosarcomatosis with Rothmund-Thomson syndrome.
Authors: el-Khoury J M , Haddad S N , Atallah N G
Published: June 2014

We describe the second reported case of multicentric osteosarcoma associated with Rothmund-Thomson syndrome (RTS), a rare hereditary cancer-prone genodermatosis characterized by typical cutaneous lesions and other non-dermatological pathological manifestations, particularly skeletal changes. A high incidence of malignant disorders has been found in RTS patients. This could be explained by the diminished capacity of DNA-repair demonstrated in the fibroblasts of RTS patients following exposure to oncogenic stimuli. The severe cutaneous lesions and the benign bone lesions found in RTS may be considered a predisposing factor to the particularly frequent skin carcinoma and osteogenic sarcoma encountered in these cancer-prone patients. A brief review of the literature is given, with a discussion of the association between these two rare conditions.
The ultrasound appearances of galactocoeles.
Authors: Stevens K , Burrell H C , Evans A J , Sibbering D M
Published: June 2014

Galactocoeles are an uncommon cause of breast masses, usually occurring in lactating women. The purpose of this study was to review the ultrasound (US) features of galactocoeles presenting to the Nottingham Breast Unit. Eight women with galactocoeles were scanned during 1994 and 1995. All the scans were abnormal, 50% of lesions were cystic or multicystic, 37% mixed cystic/solid and 13% appeared solid. A fat-fluid level was seen in only one case. Two of the cystic/solid lesions had ill defined solid components, raising the possibility of an intracystic carcinoma. All cases were confirmed by the aspiration of milk and clinical resolution following aspiration.
Application of computer texture analysis to the Singh Index.
Authors: Smyth P P , Adams J E , Whitehouse R W , Taylor C J
Published: June 2014

The Singh Index, which describes trabecular patterns in the proximal femur, has been used as a predictor for hip fractures and as an indicator of osteopenia. Evidence suggests that its contribution to the assessment of hip fracture risk is in its description of the structural properties of the femur. However, subjectivity in its determination may limit its practical value. In this study, we have used computer texture analysis to characterize the textural changes in trabecular bone which occur in osteoporosis. Texture analysis of the proximal femur was used to rank radiographs of 25 cadaver femora by Singh grading. These rankings were compared with those performed by two experienced radiologists. The computer method performed better than the least consistent individual radiologist, but not as well as the two radiologists in combination. The method required no radiologist's time after the system had been 'trained' from a set of example radiographs. The method has potential for use in large studies in which speed and consistency of measurement are important.
Hepatic artery thrombosis and infarction: evolution of the ultrasound appearances in liver transplant recipients.
Authors: Cook G J , Crofton M E
Published: June 2014

Hepatic infarction is a serious complication of liver transplantation, causing significant morbidity and mortality and often requiring retransplantation. Real time ultrasonography with Doppler examination is often the first imaging modality employed to investigate post-operative complications. We report on the sonographic appearances of three patients in whom hepatic infarction followed transplantation but who did not require retransplantation, allowing us to study the evolution of sonographic features. Geographic areas of decreased echogenicity with preservation of the portal tracts are an early sign of hepatic ischaemia and may either resolve completely or progress to true infarction with the development of transient small hyperechoic lesions. Calcification may also occur quite rapidly. Biliary strictures, bilomas and abscess formation are later complications.
The role of metallic stents in malignant duodenal obstruction.
Authors: Scott-Mackie P , Morgan R , Farrugia M , Glynos M , Adam A
Published: June 2014

Malignant duodenal obstruction is a common complication of carcinoma of the head of the pancreas. We report successful palliative treatment of malignant duodenal strictures by the peroral placement of metallic endoprostheses in two patients in whom palliative surgery was not possible.
Optimization and deconvolution of lithium fluoride TLD-100 in diagnostic radiology.
Authors: Burke K , Sutton D
Published: June 2014

Lithium fluoride (LiF) TLD-100 is one of the most commonly used thermoluminescent (TL) materials for the measurement of entrance surface dose (ESD) in diagnostic radiology. However, the minimum detectable dose (MDD) achieved, as derived from measurements of the random uncertainty present in the background signal, is usually quoted as being 50-100 microGy. A more appropriate definition of MDD for use in the clinical setting is the dose at which measurements exhibit a specified level of random uncertainty. This definition will give rise to a higher value for the MDD. An MDD of 50-100 microGy precludes accurate measurement of ESD in high tube potential (kVp) chest or neonatal radiography. Techniques described in the specialist literature for the reduction of the MDD of LiF were assessed both in the laboratory, and during a patient dose survey of high kVp chest radiography. Optimization of the pre-irradiation annealing and post-irradiation TL read heating cycles in terms of sensitivity and precision resulted in an MDD of 5/80 microGy (derived from background signal variation and 20% random uncertainty at 95% confidence limits, respectively). Deconvolution of the glowcurve was found to result in an MDD of approximately 10 microGy. Clinical measurements were contrasted with calculated values derived from ionization chamber measurements of tube output. The results support the hypothesis that glowcurve deconvolution permits the measurement of ESDs from low dose examinations using basic TL dosimetry equipment available to virtually all medical physics departments.
Estimation of fetal and effective dose for CT examinations.
Authors: Adams E J , Brettle D S , Jones A P , Hounsell A R , Mott D J
Published: June 2014

Doses from CT examinations are difficult to estimate. However, they are requested more frequently due to the increase in CT examinations. In particular, fetal dose estimations are frequently required for patients who have discovered, subsequent to the examination, that they were pregnant when the examination was conducted. A computer model has been developed to facilitate such dose calculations. This model combines empirical beam data with anatomical information. The model has been verified using thermoluminescent dosemeter (TLD) readings of internal and surface dose from both phantoms and patients, including intrauterine doses for patients undergoing afterloading gynaecological intracavitary treatment. Although only limited experimental data were available, the results indicate that the model accurately predicts uterine doses within acceptable errors. This approach has been validated for fetal dose estimation. The model was also used in a comparison with the nationally available CT dose data from the National Radiological Protection Board (NRPB). The two models were found to be in agreement for fetal dose estimations.
Involvement of the inferior vena cava by adrenal phaeochromocytoma--MRI findings.
Authors: Lau T N , Goddard P , Vaidya M , Calloway M , Bullimore J
Published: June 2014

Involvement of the inferior vena cava (IVC) by adrenal phaeochromocytoma is rare. Only angiographic and sonographic features have been described previously. We present a case with magnetic resonance demonstration of the IVC invasion.
Ectopic pancreas complicated by pancreatitis and pseudocyst formation mimicking jejunal diverticulitis.
Authors: Rubesin S E , Furth E E , Birnbaum B A , Rowling S E , Herlinger H
Published: June 2014

Clinical symptoms are rarely produced by ectopic pancreas arising in the jejunum. We report a case of a patient with left lower quadrant abdominal pain due to jejunal ectopic pancreas complicated by acute pancreatitis and pseudocyst formation.
Does magnetic resonance imaging make a difference for patients with musculoskeletal sarcoma?
Authors: Bloem J L , van der Woude H J , Geirnaerdt M , Hogendoorn P C , Taminiau A H , Hermans J
Published: June 2014

MR imaging has had an unparalleled impact on the treatment of patients with musculoskeletal sarcoma. Basically, the high accuracy of local staging has made the introduction of reconstructive and limb salvage procedures instead of amputation of disarticulation available to the majority of patients with musculoskeletal sarcoma. Pre-operative work-up with MRI is not only more accurate, but also much faster and cheaper than the conventional work-up. Staging is the single most important reason for performing MR imaging in patients with musculoskeletal tumours. The impact of MR specificity is less dramatic but the benefit to the patient is an increased safety margin. When diagnostic errors with devastating consequences are made nowadays, it is usually because the proper protocol has not been followed. A patient with a potentially malignant, or equivocal, musculoskeletal mass deserves to have a combined radiographic-MRI examination prior to invasive procedures. MRI does not currently have a major impact on chemotherapy decisions and colour Doppler ultrasound has a higher accuracy than MRI. However, selected cases, i.e. intraosseous tumours, dynamic Gd-enhanced MRI, can replace colour Doppler ultrasound.
The antenatal diagnosis of fetal abnormalities: a 10 year audit of influencing factors.
Authors: Dillon E , Walton S M
Published: June 2014

During the 10 years 1984-1993, a total of 438 fetuses and children with a congenital abnormality, identified antenatally or in the first year of life, were registered from the North Tees Health District with the Northern Region Congenital Abnormality Survey (NorCAS). This represented an abnormality rate of 2% of all births. In total, 252 structural abnormalities (57.5%) were detected by antenatal ultrasound examination. In spite of a targeted education programme, identification of cardiac lesions remained poor. The detection of structural abnormality by antenatal scan rose from 52% in 1984 to 85% in 1993, due mainly to improvements in image quality and resolution of ultrasound equipment. Also important was audit, based both on review of images and feedback from a comprehensive central register (NorCAS).
Bolus dynamics: theoretical and experimental aspects.
Authors: Blomley M J , Dawson P
Published: June 2014

This paper analyses the arterial enhancement produced by short intravenous boluses of iodinated contrast medium, with particular attention to the differences between various types of contrast media. A theoretical discussion is presented, followed by a small experimental study. The characteristics of the arterial time-attenuation curve are a function of the rate of contrast medium transit to the extracellular fluid (ECF), osmolality driven transit of water from the ECF into the plasma, direct effects on the heart and pulmonary circulation, the distribution of transit times in the cardiopulmonary circulation and recirculation. Theory predicts that while differences in peak arterial attenuation/peak height (PH) will be small, alterations in the areas under the time-attenuation curve (AUC) will reflect early-phase rate constants in the absence of major inotropic effects. The AUC should be higher for non-ionic than ionic media reflecting these lower rate constants. An experimental study on three healthy dogs confirmed these theoretical observations, with a slightly higher PH (6.5% higher) using a non-ionic medium but a substantially higher AUC (22% higher). (Differences significant at the 5% level, two-tailed paired t-test.) Our theoretical predictions and experimental findings suggest non-ionic media produce superior vascular enhancement, particularly shortly after injection. Possible clinical implications, particularly in dynamic enhanced computed tomography, are discussed.
Survey of CT techniques and absorbed dose in various Dutch hospitals.
Authors: Van Unnik J G , Broerse J J , Geleijns J , Jansen J T , Zoetelief J , Zweers D
Published: June 2014

The purpose of this study was to make an inventory of the radiation dose from CT in the Netherlands and to relate the dose to the way the examination was performed. Details were obtained from approximately 3000 CT examinations carried out in 18 hospitals (22 CT scanners). Effective dose was calculated for each examination using CTDI-to-effective dose conversion factors. For most scanners, the conversion factors were available from the literature, for some they had to be derived with a computer model using a Monte Carlo algorithm. The data on effective dose, examination parameters and patient population are presented on a per hospital basis. Mean effective doses from brain CT were 0.8-5 mSv, from lumbar spine CT 2-12 mSv, from chest CT 6-18 mSv and from abdominal CT 6-24 mSv. The general indications for the various CT examinations were as follows: for the brain ischaemia and malignancy, for the lumbar spine disc herniation and for the chest and abdomen a known malignancy. This explains the relatively advanced age of the patients. In many hospitals intravenous contrast is used less than is recommended in current literature.
The use of carbon fibre material in radiographic cassettes: estimation of the dose and contrast advantages.
Authors: Dance D R , Lester S A , Carlsson G A , Sandborg M , Persliden J
Published: June 2014

A Monte Carlo simulation has been used to estimate the dose and contrast advantages of replacing radiographic cassette fronts fabricated from aluminium with cassette fronts fabricated from low atomic number material (carbon fibre). The simulation used a realistic imaging geometry and calculations were made both with and without an anti-scatter grid. Account was taken of the scatter generated in the cassette front and the effect of beam hardening on primary contrast. Dose and contrast were evaluated for a range of cassette front thicknesses and tube potentials (60-150 kV) as well as for four examinations representative of situations with varying amounts of scatter. The results with an anti-scatter grid show a clear dose and contrast advantage in all cases when an aluminium cassette front is replaced with a low attenuation cassette front. The contrast advantage is dependent upon the examination and is generally greater for imaging bony structures than for imaging soft tissue. If a 1.74 mm aluminium cassette front is compared with a 1.1 mm carbon fibre cassette front, then the dose advantages are 16%, 9%, 8% and 6% and the contrast advantages are 10%, 7%, 4% and 5% for the AP paediatric pelvis examination at 60 kV, the anteroposterior (AP) lumbar spine examination at 80 kV, the lateral lumbar spine examination at 100 kV and the posteroanterior (PA) chest examination at 150 kV, respectively. The results without an anti-scatter grid show an increased dose advantage when a low attenuation cassette front is used, but the contrast advantage is small and in some situations negative.
Modification of the response of a quiescent cell population within a murine solid tumour to boron neutron capture irradiation: studies with nicotinamide and hyperthermia.
Authors: Masunaga S , Ono K , Suzuki M , Takagaki M , Sakurai Y , Kobayashi T , Akuta K , Akaboshi M , Kinashi Y , Abe M
Published: June 2014

C3H/He mice bearing SCC VII tumours received 5-bromo-2'-deoxyuridine (BrdU) continuously for 5 days via implanted mini-osmotic pumps, to label all proliferating (P) cells. 20 min after intraperitoneal injection of sodium borocaptate-10B (BSH), or 3 h after oral administration of dl-p-boronophenylalanine-10B (BPA), the tumours were irradiated with thermal neutrons. To modify the uptake dose of 10B, nicotinamide (NA) was intraperitoneally injected 60 min before the administration of 10B-compounds and/or the tumours were heated to 41.5 degrees C for 20 min immediately before irradiation. After irradiation, the tumours were excised, minced and trypsinized. The tumour cell suspensions were then incubated with cytochalasin-B (a cytokinesis-blocker). The micronucleus (MN) frequency in cells not BrdU-labelled (quiescent (Q) cells) was determined using immunofluorescence staining for BrdU. With or without the administration of 10B-compounds, the sensitivity of Q cells was lower than that of total (P + Q) tumour cells. With thermal neutron irradiation in the presence of either BPA or BSH, the MN frequency in each cell population was increased. A greater increase in the MN frequency of total tumour cells was observed after thermal neutron irradiation in the presence of BPA than in the presence of BSH. The distribution of 10B from BPA into tumour cells was thought to be more dependent on the uptake ability of the tumour cells than that from BSH. Sufficient quantity of 10B from these two 10B-compounds to cause a highly lethal event inside the cancer cell with thermal neutron irradiation could not be delivered to Q cells. When NA and/or heat treatment were combined with 10B-compound administration, NA increased MN frequency in the BSH treated total cells, and heat treatment elevated MN frequency in Q cells. From the viewpoint of cell kill effect, the combined treatment with nicotinamide and heat treatment was more useful than treatment with either nicotinamide or heat treatment alone, not only in the total tumour cells but also in the Q cells.
Film viewing conditions in mammography.
Authors: Hill S J , Faulkner K , Law J , Starritt H C
Published: June 2014

A requirement for a minimum viewing box brightness of 3000 cd m-2 for reading mammograms has been widely advocated. Some recent work has challenged that opinion by reporting no significant variation in visibility of low contrast and fine detail objects over a wide range of brightness levels. This paper provides further experimental evidence to support the latter conclusion, at least over the range 1340-4190 cd m-2, and suggests that the currently recommended minimum viewing box brightness levels need to be revised. The importance of reducing room lighting levels is fully confirmed.
Intracavitary radiotherapy boosting for nasopharynx cancer.
Authors: Slevin N J , Wilkinson J M , Filby H M , Gupta N K
Published: June 2014

Intracavitary radiotherapy is conceptually an attractive method of boosting dose to nasopharynx cancer whilst sparing sensitive normal tissues. A high dose rate (HDR) microselectron can be used to deliver a brachytherapy boost conveniently, safely, comfortably and effectively. Following external radiotherapy a single outpatient treatment has been given to patients using the remote afterloading system of sources placed in modified paediatric endotracheal tubes. This has been associated with good primary control and no evidence of serious morbidity in eight patients. The main limitation of this method is restriction of its utilization to small volume primary disease.
Dynamic MR imaging of invasive breast cancer: correlation with tumour grade and other histological factors.
Authors: Mussurakis S , Buckley D L , Horsman A
Published: June 2014

The purpose of this study was to explore the association between dynamic MR enhancement characteristics and histopathological prognostic factors of invasive breast cancer. 53 women with primary invasive breast cancer underwent dynamic contrast enhanced breast MRI. Region of interest (ROI) analysis was performed on synthetic images obtained by kinetic modelling of the dynamic data. Operator-defined, large ROIs and computer-defined, 9-pixel ROIs were selected for each tumour. The relative increase in mean ROI pixel intensity was expressed in the form of enhancement ratios. Univariate and multivariate analyses were performed to explore the association of these ratios with standard histological factors, including tumour size, histopathological classification, histological grade, the presence of extensive in situ component and lymphovascular invasion, multifocal disease, and axillary lymph node status. All enhancement ratios showed significant differences between node-positive and node-negative tumours (max. p = 0.002). However, automated ROI ratios showed less overlap between node-positive and node-negative carcinomas than did large ROI ratios. A strongly significant association was observed between all automated ROI enhancement ratios and histological tumour grade (max. p = 0.001). Based on stepwise multiple regression analysis, node status and histological grade were the only histopathological factors with a significant independent effect on the enhancement characteristics. In summary, there is a strong association between dynamic MR characteristics and two important prognostic markers of invasive breast cancer, namely axillary node status and histological grade. This may allow MRI to be used in pre-operative predictions of tumour behaviour and biological activity.
The impact of cardiology on the collective effective dose in the North of England.
Authors: Broadhead D A , Chapple C L , Faulkner K , Davies M L , McCallum H
Published: June 2014

Two cardiology X-ray rooms were monitored with dose-area product meters as part of a Regional Patient Dosimetry Programme. Dose-area product measurements on over 2000 patients undergoing examinations in the cardiology rooms are presented. The data have been corrected according to patient size where possible. In room A mean dose-area product values for coronary angiography, coronary angioplasty, radiofrequency ablation and mitral valvuloplasty were found to be 47.7, 72.2, 91.1 and 161.9 Gy cm2 respectively. In room B mean dose-area product values for coronary angiography and coronary angioplasty were found to be 23.4 and 51.6 Gy cm2 respectively. Observational studies were used to deduce the typical projections and technique factors. This typical examination was used to simulate an angiogram from which it was possible to derive factors to convert measured dose-area product values into estimates of effective dose. In room A, the effective doses were estimated to be 9.4, 14.2, 17.3 and 29.3 mSv for coronary angiography, coronary angioplasty, radiofrequency ablation and mitral valvuloplasty, respectively. The effective doses during coronary angiography and coronary angioplasty, performed in room B, were found to be 4.6 and 10.2 mSv, respectively. A regional survey of the frequency of these cardiac procedures was performed. It was deduced that the annual collective effective dose from these cardiac procedures in the North of England, the former Northern Region, was 45.7 manSv.
The interdependence of staff and patient doses in interventional radiology.
Authors: Williams J R
Published: June 2014

Staff doses arising from the use of X-rays are principally due to scattered radiation. This is related to the dose received by the patient expressed as the dose-area product (DAP). Doses to patients in interventional radiology are generally higher than for other fluoroscopically guided procedures. Doses to interventional radiologists are, therefore, amongst the highest associated with the use of diagnostic X-rays. The results of staff dose monitoring normalized to DAP should provide an indicator of those procedures which are associated with particularly high radiation exposures to staff, and should help to identify those radiologists whose practice may result in unnecessarily high doses to themselves. A study has been made of patient doses in two X-ray rooms used for interventional procedures associated with vascular and liver diseases. Doses to radiologists in these rooms were normalized to DAP. It was found that the average doses to the body, neck and hands were 0.05, 0.89 and 2.45 microSv/(Gy cm2), respectively for those radiologists with no significant involvement in hepatobiliary procedures. Higher doses were found for one radiologist whose workload included biliary drainage. The whole body dose was 0.17 microSv/(Gy cm2) or 5.8 mSv per year. It was shown that the doses to the neck and hands for the biliary drainage work was 6.59 and 29.0 microSv/(Gy cm2), respectively. This study has demonstrated the value of DAP as a measure of radiologist workload in respect of its significance in terms of staff dose.
The effect of cortical endplates on ultrasound velocity through the calcaneus: an in vitro study.
Authors: Njeh C F , Langton C M
Published: June 2014

Ultrasound velocity has been reported as a good predictor of bone strength measured in vitro using standard mechanical testing techniques. Such mechanical investigation of bone strength cannot be carried out in vivo, because of the invasive nature of the testing. Therefore to be able to extrapolate the in vitro findings to the clinical situation, the effect of cortex on ultrasound transmission velocity through the calcaneus is required. This was investigated in vitro by measuring ultrasound velocity through samples of different modification using a CUBAResearch ultrasound machine. The different sample modifications were: "whole" (soft tissue removed), "core" (cylindrical sample), "can" (cancellous sample without the cortex) and "def" (defatted cancellous sample). Ultrasound transmission velocity for the various sample modification were highly correlated with each other (r = 0.80-0.97). Coring resulted in a 0.77% increase in the mean velocity. Substituting bone marrow (defatting) with water at room temperature had no measurable effect on the ultrasound velocity. The velocity in the whole samples and the cancellous samples were statistically different with the cortex introducing only a 2% increase in the ultrasound velocity. Therefore the in vivo ultrasound velocity measured at the calcaneus is determined mainly by the cancellous bone component which is more sensitive to osteoporotic changes. Hence the reported ability of ultrasound velocity in vitro to predict bone strength could be expected in vivo.
Adenoid cystic carcinoma of the external auditory canal: correlation between histological features and MRI appearances.
Authors: Aikawa H , Tomonari K , Okino Y , Hori F , Ueyama T , Suenaga S , Bundo J , Tsuji K
Published: June 2014

A rare case of adenoid cystic carcinoma of the external auditory canal with magnetic resonance imaging appearances is reported. Both T1 weighted and T2 weighted MR images showed the tumour as a hypointense mass, although there was marked contrast enhancement. Microscopic examination of the resected tumour showed a preponderance of solid tumour cell nests. According to previous reports, these pathological and radiological findings indicate a poor prognosis.
Obliteration of maxillary and sphenoid sinuses in Gaucher's disease.
Authors: Karabulut N , Ahmetoglu A , Ariyürek M , Erol C , Gürakan F
Published: June 2014

Paranasal sinus obliteration is described in a patient with adult type Gaucher's disease. Plain radiographs and computed tomography showed obliteration of paranasal sinuses due to medullary expansion of surrounding bone. The mandible and maxilla are rarely affected in Gaucher's disease and obliteration of paranasal sinuses due to bony expansion has not previously been reported.
Uncommon features of abdominal aortoiliac disease.
Authors: Griffith J F , Yang W T , Lam W W , Metreweli C
Published: June 2014

This pictorial review illustrates the cross-sectional imaging of several less common manifestations of aortoiliac disease. Despite their varying clinical features, the imaging appearances with ultrasound, CT and MRI will allow a correct assessment in most cases.
Early detection of locally recurrent rectal cancer by endosonography.
Authors: Rotondano G , Esposito P , Pellecchia L , Novi A , Romano G
Published: June 2014

After curative surgery for rectal cancer, the goal of an aggressive surveillance programme is the detection of local recurrence (LR) at an early and potentially curable stage 62 patients (mean age 66.2 years) operated on for rectal cancer were prospectively enrolled in a follow-up study including endorectal ultrasound (EUS), serial CEA levels, digital examination, colonoscopy and pelvic CT. A total of 192 sonographic scans were performed, with a mean of three (range 2-7) for each patient. LR occurred in 11 patients; in all cases this was suggested by EUS. In two patients (18%) other techniques had failed to detect recurrent disease, which was identified solely by EUS. These two were treated radically and the remainder received radiotherapy or other palliative management. Five patients are alive at, on average, 18 months after LR (range 4-26 months). These include both cases treated with salvage surgery and who remain disease free. EUS is a valuable tool in the detection of locally recurrent rectal cancer.
Male and female normative data for ultrasound measurement of the calcaneus within the UK adult population.
Authors: Langton C M , Langton D K
Published: June 2014

The establishment of accurate normative data for specific populations is required before ultrasound bone densitometry may be considered for routine clinical application. A single general practice was utilized, representing both rural and urban populations, to recruit 169 male and 210 female subjects in the age range 20-80 years. Measurements of broadband ultrasound attenuation (BUA) and velocity (VOS) of the left calcaneus were undertaken using the McCue CUBAClinical II system. Two descriptive statistical models were used, mean and 95th percentile, and regression analysis. The female data for both BUA and VOS illustrated peak values in the 30-39 years age group, falling steadily thereafter. For male BUA and VOS data there was less evidence of an age related dependence. Upon analysis of previous normative studies and current data it is evident that there is considerable variability. In addition to different commercial systems being utilized, there is a lack of consistency in study design and method of subject recruitment. The need for accurate calibration and cross-calibration methods for commercial ultrasound bone densitometers is therefore of paramount importance to enable clinical interpretation of ultrasound measurements to be performed.
Human biodistribution of an ultrasound contrast agent (Quantison) by radiolabelling and gamma scintigraphy.
Authors: Perkins A C , Frier M , Hindle A J , Blackshaw P E , Bailey S E , Hebden J M , Middleton S M , Wastie M L
Published: June 2014

The biodistribution and kinetics of an air filled human serum albumin microcapsule formulation (Quantison) intended for use as an intravenous ultrasound contrast agent have been examined. 12 healthy subjects were administered with approximately 50 million microcapsules per kilogram body weight, radiolabelled with 50 MBq 123I. Imaging was performed over a period of 58 h using a large field-of-view gamma camera and the amount of labelled material present in the blood, urine and faeces measured. Imaging demonstrated that the liver was the organ with the highest uptake, with a mean uptake of 41.8% (SD 10.4%) of the administered dose 1 h following administration. The maximum uptake of the agent in the lungs was low, mean 4.0% (SD 3.4%). A small amount of uptake was visible in the bone marrow; however, this was not quantifiable. There was also evidence of minimal myocardial activity within 5 min of administration. No adverse events were observed and there were no changes in any of the individual post-study indices. The present study demonstrates the safety of Quantison. Gamma scintigraphy played a useful role in confirming the biodistribution of the agent with little lung uptake, high liver uptake and evidence of myocardial uptake.
Assessment of lifetime gained as a result of mammographic breast cancer screening using a computer model.
Authors: Jansen J T , Zoetelief J
Published: June 2014

A computer model for the simulation of breast cancer screening (MBS) is used to calculate the results of screening in terms of lifetime. To optimize breast cancer screening protocols, risk (lifetime lost due to radiation-induced tumours) versus benefit (lifetime gained due to early detection of breast cancer) analyses are performed for a simulated stable Swedish female population. The present study focuses on the results of different screening strategies employing single view mammography, including starting and finishing ages of screening, time interval between successive screening sessions as well as the influence of high detection screening and differences between different populations, based on lifetime lost or gained. To test the stability of the recommendations with respect to possible changes in the variables used in MBS, calculations are also performed for high risk factors for breast tumour induction using both the additive and multiplicative risk models, fast growing breast tumours, late incidence of breast tumours and age dependent survival. The results of the simulations expressed in terms of lifetime gained suggest that a theoretical benefit can be obtained employing starting and finishing ages of 35 and 75 years, respectively. In terms of number of fatal breast tumours, the favourable screening period is 40-80 years. It is concluded that the recommendations are stable for changes in the input variables of MBS. The benefits of higher detection screening are more marked for younger than for older women. A high screening frequency results in more lifetime gained, especially at relatively young ages, whereas for older ages the effect is only marginal.
Evaluation of a new ultraviolet-emitting rare-earth film-screen combination.
Authors: Farajollahi A R , Sutton D
Published: June 2014

The performance of a 400 speed class DuPont Ultra Vision Rapid (UVR) film-screen combination has been evaluated and compared with that of DuPont Quanta Fast Detail screens with Cronex 10L film (QFD-200 speed class). The speed was calculated from the constructed characteristic curves (H&D) at different energies. Image quality was derived objectively using the Leeds test object TOR (CDR). An anthropomorphic phantom was then employed to determine image quality subjectively by means of radiologist appraisal. Lumbar spine and chest radiography of patients were performed to evaluate the potential for dose reduction in clinical conditions by measuring skin entrance doses with thermoluminescent dosimeters (TLDs). UVR provided better resolution (9 lp mm-1 as opposed to 8 lp mm-1) and contrast response than QFD. UVR has accommodated a wider exposure latitude than might be expected with conventional 400 speed class film-screen combinations. Use of UVR resulted in better image quality than use of QFD over a wide range of exposure factors. The use of UVR can result in a dose reduction of 50% with no loss in image quality.
Monitor unit calculation in 6 MV irregularly shaped beams--accuracy in clinical practice.
Authors: Lombardi P , Fiorino C , Cattaneo G M , Calandrino R
Published: June 2014

The results of an investigation of the accuracy of monitor unit (MU) calculation in clinical shaped beams are presented. Measured doses at the reference depth on the beam central axis (isocentre) or on a beam axis representative of the irradiated area (when the isocentre lies under a block or near the edges of the block's shadow) were compared with the expected doses when calculating MUs, by applying different methods normally used in clinical practice. Empirical (areas weighted, Wrede) and scatter summation (Clarkson) methods as well as a pencil-beam based algorithm were applied. 40 irregular fields (6 MV X-rays, CLinac, Varian 6/100), divided into six categories, were considered. Dose measurements were performed with a NE2571 ionization chamber in an acrylic 30 x 30 x 30 cm3 phantom. The depths in acrylic were converted into water-equivalent depths through a correction factor derived from TMR measurements. The method of dose measurements in acrylic was found to be sufficiently accurate for the purpose of this study by comparing expected and measured doses in open square and rectangular fields (mean deviation +0.2%, SD = 0.5%). Results show that all the considered methods are sufficiently reliable in calculating MUs in clinical situations. Mean deviations between measured and expected dose values are around 0 for all the methods; standard deviations range from 1% for the Wrede method to 0.75% for the pencil-beam method. The differences between expected and measured doses were within 1% for about 3/4 of the fields when calculating MUs with all the considered methods. Maximum deviations range from 1.6% (pencil-beam) to 3% (Wrede). Slight differences among the methods of MU calculation were revealed within the different categories of blocked fields analysed. The surprising agreement between measured and expected dose values obtained by using empirical methods (area weighted and Wrede) is probably due to the fact that the reference points were positioned in a "central" region of the unblocked areas.
Sagittal vertebral body fractures: magnetic resonance imaging features.
Authors: Harvey C J , Saifuddin A , Nordeen M H , Taylor B A
Published: June 2014

Isolated sagittal vertebral body fractures are rare and the plain radiographic diagnosis may be difficult. We report two cases, confirmed by CT, and describe the subtle MRI features which comprised increased signal intensity only on the midline sagittal T2 weighted images. In one case, the information from MRI significantly altered the patient's management by leading to a change from surgical to conservative treatment.
Hydatid cyst of the liver communicating with the left colon.
Authors: Lo Casto A , Salerno S , Grisanti M , Mastrandrea G
Published: June 2014

Rupture and secondary infection are common complications of hydatid cyst in the liver. Ultrasound and CT findings are reported in a case of hydatid cyst which has ruptured directly into the left colon. Rupture of hydatid cyst into a hollow viscus is extremely rare. CT demonstrated partial drainage of the cyst contents with the creation of an air-fluid level.
Transvaginal leak of peritoneal dialysate demonstrated by CT peritoneography.
Authors: Bradley A J , Mamtora H , Pritchard N
Published: June 2014

CT peritoneography is the investigation of choice for suspected leaks or hernias in patients on continuous ambulatory peritoneal dialysis (CAPD). We report a case of transvaginal leak of peritoneal dialysate in a young woman, confirmed by CT peritoneography. CAPD has been successfully recommenced following the repair of a left vaginal vault erosion.