bluuebunny/crossref_metadata_2025 huggingface dataset:
Bone mass assessment in rats by dual energy X-ray absorptiometry.
Authors: Gala Paniagua J , Díaz-Curiel M , de la Piedra Gordo C , Castilla Reparaz C , Torralbo García M
Published: June 2014

At present there are many techniques available for determining bone mass, measurement of which is essential for monitoring osteopenia. Rats are preferred to other laboratory species when designing animal studies on osteoporosis. The precision and accuracy of dual energy X-ray absorptiometry (DXA) for the assessment of bone mineral density (BMD) and bone mineral content (BMC) in laboratory animals were assessed. Precision, expressed as a coefficient of variation (CV), was measured, making five determinations (Hologic QDR-1000) on lumbar spine (in vivo) and femur (in vitro), both with and without repositioning. The correlation (r) between densitometric parameters and mineral content of bone ashes was calculated both in lumbar spine (in vivo) and in femur (in vitro). In our study, DXA had good precision, better in femur (CV 0.53%) than in lumbar spine (L2-L4) (CV 1.0%). Repositioning did not increase significantly the coefficients of variation (CV 0.61% and 1.2%, respectively). The linear regression between BMD and ash weight, calcium and phosphorous content showed high correlation coefficients (r = 0.64-0.85, p < 0.05). Although we found an overestimate of values of BMC with respect to ash weight (21% in lumbar spine and 31% in femur), the correlation between BMC and mineral content was high (r = 0.96-0.99, p < 0.05). The results suggest that the DXA technique has the precision necessary when used to assess BMD and BMC in small laboratory animals.
Predictive value of clinical examination, transrectal ultrasound and magnetic resonance imaging prior to radiotherapy in carcinoma of the cervix.
Authors: Hawnaur J M , Johnson R J , Carrington B M , Hunter R D
Published: June 2014

The objectives of this study were to compare tumour staging and volume assessment by examination under anaesthesia (EUA), transrectal ultrasound (TRU) and magnetic resonance imaging (MRI) in patients with invasive carcinoma of the cervix, and to correlate findings with long-term outcome following treatment by radiotherapy. Tumour staging was performed on 60 patients immediately before starting radiotherapy. Clinicians and radiologists performing EUA, TRU or MRI were blinded to the results of other investigations. Tumour stage and dimensions were recorded prospectively for each technique, and analysed for concordance. The relationship between pre-treatment stage, size of tumour and patient outcome after radiotherapy was assessed, using clinical status 5 years after treatment as the truth measure. EUA, TRU and MRI assigned the same tumour stage in only 30% of patients and EUA and MRI agreed tumour stage in a further 27%. In cases of disagreement, the MRI stage correlated better with outcome than the TRU or EUA stage. There was a significant difference between tumour volume obtained from measurements made on MRI and those from TRU. 62% of patients with enlarged lymph nodes on pre-treatment MRI either died, or developed tumour recurrence or metastases. The ability of MRI to assess the full extent of bulky tumours and the presence of lymph node enlargement was an advantage over both EUA and TRU in identifying patients with a poor prognosis.
Bronchial arterial angio-CT: evaluation of intradural and oesophageal enhancement before bronchial arterial infusion.
Authors: Moteki T , Ohya N , Katsuya T
Published: June 2014

Ultrafast CT combined with bronchial angiography (BA angio-CT) demonstrated a supply from the bronchial arteries to the oesophagus and spinal cord which is not identified on conventional bronchial arteriography using a digital subtraction technique. 20 patients with bronchial carcinoma and one with lung metastasis were examined using BA angio-CT, before bronchial artery infusion. 20 ml of non-ionic iodinated contrast medium (300 mgI ml-1) was injected into the bronchial artery, and ultrafast CT of the whole mediastinum was commenced when 10 ml had been injected. The 6 mm single slice mode was used and 40 images were obtained. Intradural and oesophageal enhancement was evaluated on BA angio-CT, and compared with the findings on digital subtraction angiography (DSA) of the bronchial arteries. BA angio-CT clearly showed intradural enhancement in eight patients. Marked spinal cord enhancement was demonstrated in three, and a coaxial catheter technique was used to avoid infusing the intercostal branch of the intercostobronchial trunk. Oesophageal enhancement was demonstrated in 18 patients on BA angio-CT. In contrast, no enhancement of these structures was seen on bronchial arterial DSA. In conclusion, BA angio-CT enabled precise evaluation of intradural and oesophageal enhancement.
CT scanning of the paranasal sinuses: axial helical CT with reconstruction in the coronal direction versus coronal helical CT.
Authors: Bernhardt T M , Rapp-Bernhardt U , Fessel A , Ludwig K , Reichel G , Grote R
Published: June 2014

Paranasal sinuses of 52 patients with sinusitis, tumours or fibrous dysplasia were scanned. Axially acquired spiral data were obtained and reconstructed coronally. Four radiologists compared the two sets of images. They evaluated the diagnostic quality for visualization of the ostiomeatal unit, infundibulum, infraorbital canal, inflammatory disease, fine osseous lamellae and presence of amalgam or step artefacts. Two test phantoms were scanned for both techniques and lens dose was measured. Statistical significant differences in the diagnostic quality of the representation of the fine osseous structures in the paranasal sinuses, attributable to step artefacts were found in the coronally reconstructed images (p < 0.001). However, there was no amalgam and almost no motion artefacts in the reconstructed images. Interobserver correlation was r = 0.953 versus 0.956 for inflammatory disease, r = 0.816 versus 0.852 for artefacts, and r = 0.596 versus 0.547 for fine osseous lamellae in coronally acquired or axially acquired and reconstructed images, respectively. Lens dose was measured between 11.8 mGy and 13.8 mGy for axially acquired and reconstructed images. The advantage of axially acquired, coronally reconstructed images is the absence of artefacts attributable to amalgam and fewer motion artefacts. Axially acquired, coronally reconstructed images are inferior to coronal helical CT images, because of step artefacts, when it comes to evaluating the resolution of fine osseous structures. Nevertheless, reconstructed images are suitable as a investigatory procedure for patients with inflammatory disease who cannot maintain the prone position.
Dose reduction in a paediatric X-ray department following optimization of radiographic technique.
Authors: Mooney R , Thomas P S
Published: June 2014

A survey of radiation doses to children from diagnostic radiography has been carried out in a dedicated paediatric X-ray room. Entrance surface dose (ESD) and dose-area product (DAP) per radiograph were simultaneously measured with thermoluminescent dosemeters (TLDs) and a DAP meter to provide mean dose values for separate age ranges. Results of ESD and DAP were lower than the mean values from other UK studies for all ages and radiographs, except for the infant pelvis AP radiograph. Comparison of ESD and radiographic technique with CEC quality criteria highlighted a need for reduction of dose to infants and implied an increase in tube filtration might overcome the limitations of the room's three-phase, 12-pulse generator, allowing higher tube potentials to be used on infants. Additional tube filtration of 3 mmA1 was installed following assessment of dose reduction and image quality with test objects and phantoms, and confirmation from the paediatric radiologist that clinical image quality was not-significantly altered. The tube potential was increased from 50 to 56 kVp for the infant pelvis AP radiograph. The resulting ESD and effective dose fell by 51% and 38%, respectively. The CEC quality criteria have proved useful as a benchmark against which technique in X-ray departments can be compared, and as such are a useful tool for optimizing radiographic technique and reducing patient dose.
Comparison of ultrasound and dual energy X-ray absorptiometry measurements in the calcaneus.
Authors: Kang C , Speller R
Published: June 2014

Ultrasound measurements have been proposed as a means of providing structural information on bone but have also been shown to correlate with density. High correlation coefficients have been obtained in vitro, but are lower for in vivo work. The aim of this study was to investigate the relationship of broadband ultrasound attenuation (BUA), speed of sound (SOS) and stiffness, to bone mineral density (BMD) measured in the calcaneus at a closely matched region of interest (ROI). Measurements were made in 55 post-menopausal and 20 young, normal women. Calcaneus BMD measurements were made using an ROI (fixed by reference to external axes) to represent the area and location of the ultrasound transducers and an ROI based on anatomical markers, positioned in the posterior part of the calcaneus. BUA was significantly correlated with calcaneus BMD in the fixed ROI (r = 0.77, p < 0.0001) and the anatomical ROI (r = 0.78, p < 0.0001). Correlation of BUA with axial BMD was lower at r = 0.63, p < 0.0001 for the spine (L2-L4) and r = 0.59, p < 0.0001 for the femoral neck. Results for SOS and stiffness were very similar. From the calcaneus dual energy X-ray absorptiometry (DXA) scan images the region representing the ultrasound measurement area was found to contain cortical bone edges in 60% of cases. In 16% of scans a small part (4.5 +/- 4.0%) of the ROI measurement area fell partially outside the heel. However, there was no obvious discrepancy in the ultrasound results in the individual cases where this occurred. The correlation between calcaneus BMD and BUA was improved from r = 0.72 to r = 0.86 when scans with a cortical edge in the measurement ROI were excluded. The values for SOS were similar. In summary, BMD of the calcaneus, when closely matched to the site of ultrasound measurement shows significant correlation with ultrasound measurements. By excluding scans in which the ultrasound measurement appeared to include bone edges, correlations of approximately r = 0.86 were obtained. However, the BMD result still does not explain all of the variance in the ultrasound results.
Is prostate specific antigen density an important prognostic indicator for patients with prostate cancer treated with external beam therapy?
Authors: Aref I , Eapen L , Agboola O , Cross P
Published: June 2014

The purpose of this study was to determine if prostate specific antigen density (PSAD) is a predictor of outcome following external beam radiotherapy for prostate cancer, and to compare it with other prognostic factors. Between January 1990 and December 1993, 205 patients with T1-T3 adenocarcinoma of the prostate received a radical course of external beam irradiation, with no prior or adjuvant hormonal therapy. All patients had pre- and post-treatment serum prostate specific antigen (PSA) evaluation. They were followed up for at least 24 months. PSAD was defined as the ratio of pre-treatment serum PSA to the prostate volume, as determined from CT treatment planning scans. Prostate volumes were calculated using the prostate ellipse formula. Median PSA density was 0.37, with a range 0.01-6.7. Biochemical failure was defined as three consecutive rises in serum PSA, regardless of the magnitude of elevation. 4-year biochemical disease-free survival (BDFS) for patients with PSAD < or = 0.3 was 60%, compared with 22% for patients with PSAD > 0.3 (p = < 0.001). In a multivariate analysis, pre-treatment PSA (p = < 0.001), Gleason score (p = 0.002), and stage (p = 0.03) were independent predictors of BDFS, while PSAD was not an important prognosticator (p = 0.62). Pre-treatment serum PSA is the most important prognosticator of BDFS, following external beam radiotherapy, for patients with prostate cancer. PSA density did not predict treatment outcome.
CT dimensions of the normal pericardium.
Authors: Bull R K , Edwards P D , Dixon A K
Published: June 2014

Previous studies have suggested that the upper limit of the thinnest portion of the pericardium is 3-4 mm using 10 mm CT slices. However, these studies suffered from small sample sizes, long data acquisition times and unconventional viewing parameters. We have measured the width of the thinnest portion of the normal pericardium using 10 mm (100 patients) and 1 mm (100 patients) high resolution CT (HRCT) slices with modern CT equipment and fixed mediastinal window settings (400/20). The pericardium was identified in all patients and was best seen anterior to the heart. The pericardium is exceptionally well seen using 1 mm HRCT slices and this may be the optimal technique for visualization of the pericardium. The upper limit of the thinnest portion of the normal pericardium (mean value + 2 SD) was 1.2 mm (10 mm CT slices) and 0.7 mm (1 mm HRCT slices). These values are substantially lower than those previously reported and in line with anatomical findings.
Magnetic resonance imaging of soft tissue expanders used in the management of musculoskeletal sarcomas.
Authors: Saunders A , Davies A M , Grimer R J
Published: June 2014

A soft tissue expander is surgically inserted into the body to displace radiosensitive organs from the treatment field in a small number of patients receiving radiotherapy for musculoskeletal sarcoma. MRI is routinely used to monitor the response to the radiotherapy, local recurrence and complications of treatment. This study retrospectively reviews MRI of soft tissue expanders in seven patients with musculoskeletal sarcomas; six arising in the pelvis and one in the retroperitoneum. In the absence of an appropriate clinical history, the soft tissue expander may be mistaken for a pathological fluid collection such as abscess, post-operative seroma or even recurrent tumour. MRI of the soft tissue expanders and potential errors in image interpretation are illustrated.
Determining the conditions for measurement of spatial-peak temporal-averaged intensity in scanned ultrasound beams.
Authors: Dixon K L , Duck F A
Published: June 2014

This paper describes a new three stage approach which simplifies the process of measurement of spatial-peak temporal-averaged intensity for scanned ultrasound beams. Firstly, the conditions delivering the maximum total acoustic power are determined. Secondly, out-of-plane beam-widths are measured which, together with knowledge of the in-plane scan widths, are used to locate the depth at which the scanned area is at a minimum. Finally, the spatial-peak temporal-average intensity is measured using the conditions and depth identified in the first two stages. Experimental results justify the use of this new procedure.
Aorto-oesophageal fistula presenting as a submucosal oesophageal haematoma.
Authors: Maher M M , Murphy J , Dervan P , O'Connell D
Published: June 2014

The CT findings in a fatal case of aorto-oesophageal fistula secondary to an atheromatous plaque in the thoracic aorta are described. These features are correlated with findings on endoscopy and barium studies.
Radiological findings in myxoid liposarcoma of the anterior mediastinum.
Authors: Jung J I , Kim H , Kang S W , Park S H
Published: June 2014

CT and MR findings of a rare myxoid liposarcoma involving the anterior mediastinum are reported. The mass was a low density lesion with calcific septations and some peripheral frond-like enhancement on CT. MRI showed heterogeneous intermediate to high signal intensity on T1 weighted images and high signal intensity on T2 weighted images. The signal of the mass was not suppressed on fat suppressed images.
Synovial presentation of non-Hodgkin's lymphoma.
Authors: Jamieson K A , Beggs I , Robb J E
Published: June 2014

The MRI appearances of synovial involvement from non-Hodgkin's lymphoma are described in a 61-year-old man. These appearances have not previously been described and the differential diagnosis is discussed.
Routine receiver operating characteristic analysis in mammography as a measure of radiologists' performance.
Authors: Goddard C C , Gilbert F J , Needham G , Deans H E
Published: June 2014

A system for calculating receiver operating characteristic (ROC) curves from routine audit data is described. Both diagnostic opinion and pathology outcome data from the symptomatic mammography department were recorded in an audit database, from which ROC curves were calculated. A comparison of overall radiologists' performance was made and the appropriate performance indices discussed. Similar data were collected from the breast screening centre where the same radiologists read mammograms. The radiologists' performance in the symptomatic department was compared with that in the breast screening centre and was found to be better in the screening centre. The difference could not be wholly attributed to the different age distribution of women and highlighted the different nature of the diagnostic task and the differing sampled populations. ROC curves were drawn for different clinical signs to determine any particular area of difficulty the radiologist may experience. ROC analysis as part of routine audit can be used for maintaining and improving the quality of an individual's performance, and targeting learning on areas of particular weakness.
Sonographic evaluation of focal nodular hyperplasias (FNH) of the liver with a transpulmonary galactose-based contrast agent (Levovist).
Authors: Uggowitzer M , Kugler C , Gröll R , Mischinger H J , Stacher R , Fickert P , Weiglein A
Published: June 2014

Focal nodular hyperplasias (FNH) are hypervascular, benign focal liver lesions. Differentiation of FNH from other focal liver lesions is of clinical importance. The purpose of this study was to examine the impact of a new, transpulmonary echo-enhancing agent SHU 508A (Levovist) and recent Doppler techniques in the sonographic evaluation of FNH. 43 patients with 61 focal nodular hyperplasias of the liver were examined with grey scale ultrasound and power Doppler ultrasound. Levovist, a galactose-air-microbubble suspension was administered intravenously in all patients, either by bolus injection (400 mg ml-1) or continuous pump-infusion (300 mg ml-1). Visualization of the feeding vessels and vascularity of the lesions were evaluated. The resistance indexes (RI) in the feeding vessel and the hepatic artery were assessed and compared with the diameters of the FNH. The mean diameter of FNH was 4.3 cm (+/- 1.0). Echo enhanced power Doppler ultrasound was superior to unenhanced power Doppler ultrasound in the detection of the feeding artery (85% vs. 98%) in FNH and depicted the internal vascular architecture more clearly, especially in lesions located in the left lobe of the liver. Lesions smaller than 3 cm did not show a characteristic vascular architecture with echo enhanced Doppler ultrasound. The resistance index of the feeding artery (mean: 0.51 +/- 0.08) is significantly (p < 0.0001) lower than that of the hepatic artery (mean 0.65 +/- 0.06) with a mean difference of -0.14 +/- 0.01 in the same patient. The RI of the feeding artery significantly decreased as the size of the FNH increased, whereas RI differences between the hepatic artery and the feeding artery increased with lesion size. Intravenous (i.v.) bolus injection of the contrast agent will depict the hypervascular nature of FNH more clearly than i.v. infusion, although the latter will significantly prolong the diagnostic window. In conclusion, i.v. infusion of Levovist improves the visualization of the feeding artery and the radiating vascular architecture in FNH located in the left lobe of the liver due to improved signal-to-noise ratio and results in more effective suppression of motion artefacts. Although echo enhanced Doppler ultrasound improves the detection of the low resistance arterial feeding vessel in small FNH, it will not, however, reveal a specific vascular pattern in these lesions.
Patient dosimetry in hysterosalpingography: a comparative study.
Authors: Gregan A C , Peach D , McHugo J M
Published: June 2014

Ovarian doses for 45 women undergoing hysterosalpingography (HSG) at our institution were calculated. Lithium borate thermoluminescent dosemeters were used to measure entrance surface doses in standard positions. The study compares the estimated dose received by 21 patients undergoing the procedure using an analogue fluoroscopic unit and standard film-screen radiography with that received by 24 patients who were imaged using a digital screening system with a C-arm. Our results show significant dose reduction is obtainable for patients undergoing HSG when a digital system is employed.
Radiotherapy planning techniques for thyroid cancer.
Authors: Harmer C , Bidmead M , Shepherd S , Sharpe A , Vini L
Published: June 2014

External beam radiotherapy has a role in each histological type of thyroid cancer. For treatment confined to the thyroid bed, an antero--oblique wedged pair of beams is simple to apply. More frequently, however, the volume needs to include both sides of the neck and adequate dose must be given down to the level of the suprasternal notch, precluding use of lateral fields. Thus, anterior and posterior fields are usually necessary, extending from the tips of the mastoid processes or hyoid down to the carina and laterally to include both sides of the neck and supraclavicular fossae. The mandible and infraclavicular portions of both lungs are shielded, but there is no midline lead in the phase one volume. A mid-plane dose of 46 Gy given in 23 daily fractions results in an acceptable early radiation reaction and will avoid late damage to the spinal cord. Because of considerable variation of interplanar distance along the length of the volume, a lateral simulator film should be taken to determine the maximum cord dose. For most patients, a three-dimensional CT planned phase two volume will be required and should be determined prior to completing phase one. The optimum beam arrangement, usually incorporating conformal beam shaping assisted by use of a multileaf collimator, should avoid further dose to the cord. If there is additional dose to the spinal cord, this phase can be introduced before 46 Gy is reached.
Renal malacoplakia: an important consideration in the differential diagnosis of renal masses in the presence of Escherichia coli infection.
Authors: Evans N L , French J , Rose M B
Published: June 2014

Renal malacoplakia is an uncommon condition with a variety of radiological characteristics which may initially suggest an alternative diagnosis. Three cases of renal malacoplakia were diagnosed in our hospital during a 2 year period. This apparent cluster of cases probably reflects the increased use of imaging and biopsy in the investigation of elderly hospitalized patients. It is important to make a definitive diagnosis as correct management may result in cure.
Endometroid adenocarcinoma of the cervix in a 9-year-old girl.
Authors: Palit A , McDowell H , Carty H , Rintala R , Kokai G
Published: June 2014

We present the first reported case of endometroid adenocarcinoma of the uterine cervix in a young girl. The differential diagnosis of a vaginal mass in this age group is usually rhabdomyosarcoma, although other, rarer tumours also occur.
Magnetic resonance cholangiopancreatography in the evaluation of pancreatic duct pathology.
Authors: Larena J A , Astigarraga E , Saralegui I , Merino A , Capelastegui A , Calvo M M
Published: June 2014

MR cholangiopancreatography (MRCP) may replace direct pancreatography in the evaluation of the pancreatic duct. The aim of this pictorial review is to demonstrate the usefulness of MRCP in the evaluation of pancreatic duct pathology. The examination technique included coronal, sagittal and axial breath-hold HASTE 2D imaging using a body phase array coil. We present the diagnostic features on MRCP of a variety of benign and malignant disorders of the pancreatic duct, and conclude that MRCP is a suitable method for imaging the pancreatic duct system.
Fundamentals of tracer kinetics for radiologists.
Authors: Peters A M
Published: June 2014

With the increasing application of dynamic and functional techniques to radiological imaging modalities other than nuclear medicine, it is becoming increasingly important for radiologists to understand the principles of tracer kinetics and for functional and physiological aspects of imaging to be expanded in radiological training. Tracer, or indicator, kinetics can be broken down in six fundamental physiological variables (transit time, distribution volume, clearance, extraction fraction, blood flow and permeability-surface area product), three fundamental physical variables (time, mass and volume) and three fundamental equations (transit time equation, dilution equation and Fick equation). This teaching review defines the six fundamental physiological variables, discusses their relevance to functional imaging and describes how they may be measured using radiological techniques. It also illustrates how most of their tracer kinetics are based on one or other of the three fundamental equations.
Ultrasonic heel pad thickness measurements: a preliminary study.
Authors: Rome K , Campbell R S , Flint A A , Haslock I
Published: June 2014

The heel pad has an important role in pain-free locomotion due to its shock-attenuation function. Various diagnostic techniques are available to measure heel pad thickness. Ultrasonic measurement of the heel pad is inexpensive, involves no ionizing radiation and is portable, making it an ideal screening technique. Measurement errors may occur between different ultrasonic techniques used to measure heel pad thickness. A new standardized ultrasonic technique was performed on 15 healthy volunteers. The ultrasonic measurements were compared with the measurement obtained from a normal non-weightbearing heel pad thickness ultrasonic assessment. The results demonstrated a significant mean difference (p < 0.001) between the two techniques. The 95% confidence interval of the heel pad thickness difference indicated values between 7.68 and 9.13 mm. These results suggest that a standardized technique reduces the variability of measurement error when using weightbearing ultrasound, allowing a more reproducible diagnostic technique for assessing heel pad function, and improving patient management.
Characterization and use of a commercial n-type diode system.
Authors: Wolff T , Carter S , Langmack K A , Twyman N I , Dendy P P
Published: June 2014

The characteristics of n-type diodes (linearity, temperature, dose rate, radiation damage response, directional dependence, output factors, wedge factors and percentage depth dose determinations) were investigated. Subsequently, the diodes were used clinically for in vivo dose verification during external megavoltage photon beam therapy. It has been shown that n-type diodes are easy to use and the results obtained are comparable to those reported for p-type diodes. On most occasions, n-type diodes can be used without any additional correction factors apart from regular monthly calibration. There is good agreement between the uncertainty limits estimated from the diodes' characteristics and those obtained on the basis of 2261 patient measurements.
Pneumomediastinum complicating bleomycin related lung damage.
Authors: Sikdar T , MacVicar D , Husband J E
Published: June 2014

We describe two patients who developed spontaneous pneumomediastinum without pneumothorax against a background of bleomycin-induced pulmonary interstitial disease whilst on treatment for metastatic germ cell tumours of the testis. Pneumomediastinum is a rare but recognized complication of bleomycin-induced lung toxicity, which has previously only been described in association with pneumothorax.
Protocol for measurement of patient entrance surface dose rates for fluoroscopic X-ray equipment.
Authors: Martin C J , Sutton D G , Workman A , Shaw A J , Temperton D
Published: June 2014

While patient entrance surface dose rate is an important indicator of dose performance for fluoroscopic units, there has been no standardized approach to measuring this. Since results are strongly dependent on the type of phantom used and the relative positions of the X-ray tube, intensifier and phantom, comparisons of the performance for different units are difficult to make. This document sets out a protocol for making these measurements using a standard phantom and standard configurations for different types of X-ray unit Values of dose rates which might be expected are given.
Timer error and beam quality variation during "ramp-up" of a superficial X-ray therapy unit.
Authors: Heales J C , Harrett A , Blake S
Published: June 2014

Superficial and orthovoltage therapy machines generally exhibit a "ramp-up region" during which the dose rate increases from zero to the steady state output. This can produce a significant dose deficit, which can be made up by adding a correction to the treatment time. This correction, which can be determined from the intercept of the dose versus time plot, takes no account of either the true duration of the ramp-up region or the beam quality variation while it takes place. A new method for investigating the ramp-up region is proposed, and the results are presented for a 100 kVp beam. Measurements of beam quality in terms of half value layer (HVL) have been made as a function of time. A change in HVL from an average of 2.9 mm aluminium in the ramp-up region to 3.1 mm for the steady state region has been observed. A significant random variation in the time between initiation of the radiation and the beginning of the ramp-up region was also observed which was traced to a time varying signal in the control system.
Magnetic resonance imaging of the painful wrist.
Authors: Seymour R , White P G
Published: June 2014

This pictorial review illustrates the use of magnetic resonance imaging in the assessment of the painful wrist. Careful technique is essential to optimize the accuracy of MR of the wrist. MR is the investigation of choice in avascular necrosis and has an increasing role in internal derangement, trauma and soft tissue lesions.
Dynamic intravenous coronary angiography using 2D monochromatic synchrotron radiation.
Authors: Ohtsuka S , Sugishita Y , Takeda T , Itai Y , Tada J , Hyodo K , Ando M
Published: June 2014

A method of examination for coronary artery disease that is less invasive and easier than coronary angiography (CAG) has been sought. We have developed a dynamic intravenous coronary angiography (IVCAG) system using synchrotron radiation (SR) and have used it clinically. Four patients suspected of having angina pectoris underwent IVCAG. An SR beam was reflected asymmetrically with a silicon crystal to produce a wide (150 mm x 80 mm) and monochromatic (37 keV) X-ray beam, with an energy level to achieve high sensitivity to the contrast agent. Following an intravenous injection of contrast agent, irradiation was applied for 4 ms periods at 33 ms intervals for dynamic IVCAG at 30 images s-1. Images were acquired with an image intensifier and recorded with a digital fluorography system. The dynamic images permitted clear visualization of the coronary arteries and permitted evaluation of coronary anatomy. Two patients exhibited no stenotic lesions, one patient had a 90% stenosis in the right coronary artery, and the remaining patient had a 25% stenosis at the site of previous percutaneous transluminal coronary angioplasty in the left anterior descending artery (LAD). The total irradiation doses used for IVCAG were less than those for conventional angiography. Dynamic IVCAG can be readily used for the evaluation of coronary arteries.
Radiographic exposure slide rules.
Authors: Burns J E
Published: June 2014

Before automatic exposure control was fitted to diagnostic X-ray sets, radiographers were faced with the problem of choosing the parameters that would give the best radiographic image. For a new X-ray set whose performance was unknown, this was no easy matter, and often required considerable trial and error because of the number of variables involved. To reduce the amount of work, special slide rules were invented which calculated the effect of some of these variables. Five such slide rules, dating from between about 1910 and 1950, are illustrated and discussed, including the light they shed on changes in radiographic practice over the years.
Waldenstrøm's macroglobulinaemia of the breast detected by colour Doppler ultrasound.
Authors: Lamb P M , Perry N M , Mulele C K
Published: June 2014

Waldenstrøm's macroglobulinaemia (lymphoplasmacytoid lymphoma) is a low grade B cell non-Hodgkin's lymphoma. The majority of patients present with advanced disease. Lymphoma of the breast is rare and usually arises as part of a disseminated disease process. A case of disseminated Waldenstrøm's macroglobulinaemia is reported in which the breast was involved. The findings using standard mammographic and ultrasound techniques were non-specific and only when colour Doppler examination was performed could an abnormality be detected.
Calcification of presumed ovarian carcinoma brain metastases following radiotherapy.
Authors: Henríquez I , Castro C , Berenguer J , Biete A
Published: June 2014

Multiple brain metastases from ovarian carcinoma are rare. CT findings are reported in a case treated with whole brain radiation therapy and chemotherapy. Radiological complete-calcified brain metastases following treatment and long morphological changes occurred. Delayed neurological findings in relation to treatment are considered. Long survival with unmodified calcified lesions may suggest a stabilization of CNS disease.
Intramedullary spinal metastasis from carcinoma of the cervix.
Authors: Amin R
Published: June 2014

Intramedullary spinal metastases are rare and prior to the availability of MRI were seldom diagnosed antemortem. Lung and breast carcinoma are the most common primary sources. Cervical carcinoma is the least likely source of intramedullary spinal metastases. A case of intramedullary spinal metastases is described in a 29-year-old woman with squamous cell carcinoma of the cervix.
Forensic radiology.
Authors: Kahana T , Hiss J
Published: June 2014

Imaging techniques are a powerful tool in forensic science. Medical examiners and forensic anthropologists are less versed in the finer points of radiology than radiologists; nevertheless they are required to interpret findings from imaging studies to further medico-legal investigations. The forensic investigator often should call upon the radiologist whose expertise might prove invaluable in forensic consultations. The radiologist should be aware of the importance of storing radiographs over prolonged periods of time and of efficient record keeping methods, because various legal problems may require the radiographs for additional interpretation or for their presentation in court. Some of the main issues that might be encountered in forensic radiology are discussed in this review.
The value of serial Doppler ultrasound as a predictor of clinical outcome and the need for transplantation in fulminant and severe acute liver failure.
Authors: Deasy N P , Wendon J , Meire H B , Sidhu P S
Published: June 2014

The aim of this study was to document the changes in Doppler ultrasound variables of the hepatic artery and portal vein in fulminant and severe acute liver failure, and to assess their prognostic significance. 18 adult patients with fulminant and severe acute liver failure underwent serial Doppler sonography, in the early stages after presentation. 12 hourly measurements of hepatic artery resistance index (HARI), spleen length, portal vein cross-sectional area, time average velocity (TAV) and flow volume were performed. Mean HARI (p = 0.03) and mean maximum HARI (p = 0.03) were significantly higher in those who fulfilled criteria for liver transplantation. Increased portal vein flow was demonstrated, although the difference between the groups was not significant. A significant increase in portal vein cross-sectional area (p < 0.02) and spleen length (p < 0.02) was demonstrated. In summary, an increase in portal blood flow to the damaged liver has been demonstrated. The mean HARI is significantly higher in patients who fulfil transplant criteria and may possibly be used as an indicator of poorer prognosis and the need for liver transplantation in acute severe and fulminant liver failure.
Ultrasound, CT and colonoscopy of colonic cancer.
Authors: Loftus W K , Metreweli C , Sung J J , Yang W T , Leung V K , Set P A
Published: June 2014

Barium enema and colonoscopy are commonly used for the investigation of suspected colonic cancer. These techniques are relatively invasive and both the investigation and the preceding bowel preparation are demanding, particularly in the elderly. A prospective, blinded trial was conducted to compare ultrasound (US) and CT with colonoscopy. CT and colonoscopy were performed on 50 patients with symptoms suggesting colonic cancer. Both radiological investigations were performed prior to the bowel preparation for colonoscopy. US was performed without any preparation and oral contrast medium was the only preparation used for CT. Colonoscopy detected six cancers, all of which were diagnosed by both US and CT. In addition, US and CT diagnosed a further cancer not seen on colonoscopy due to an incomplete study. US had a sensitivity and specificity of 100% and CT a sensitivity of 100% and a specificity of 84%. US and CT were poor at diagnosing polyps. If the detection of polyps greater than 2 cm is included then US sensitivity falls to 67% and CT sensitivity falls to 89% and specificity rises to 88%. In conclusion, both US and CT are possible alternatives to colonoscopy in the investigation of symptomatic patients with suspected colonic cancer. The use of these techniques could markedly reduce the need for colonoscopy in this patient population with attendant cost savings. Non-invasive imaging has particular advantages in the elderly who cope poorly with both the bowel preparation and the procedure.
Embolization of uterine fibroids.
Authors: Burn P , McCall J , Chinn R , Healy J
Published: June 2014

14 patients have undergone uterine artery embolization of uterine fibroids. No complications related to the procedure have occurred. In all six of the cases with available data, there has been a reduction in fibroid volume as measured with MRI at 2 months post procedure (average reduction 43%). Technical aspects of this promising procedure are described.
The use of soft and flexible guidewires in the treatment of chronic total coronary occlusions by activated guidewire angioplasty.
Authors: Rees M R , Michalis L K , Pappa E C , Loukas S , Goudevenos J A , Sideris D A
Published: June 2014

Activated guidewire angioplasty (AGA) is a new technique which has been designed to assist in angioplasty of total occlusions. The purpose of this study was to determine the safety and efficacy of using flexible relatively soft guidewires (floppy wires) in conjunction with this technique and also to determine the predictors of lesion crossing and final success by this technique in patients with chronic total coronary occlusions. 73 patients with 73 chronic total coronary occlusions in whom coronary angioplasty using conventional techniques had failed were treated with AGA using floppy guidewires. The success of crossing these lesions was 65.7% (48/73) resulting in a final angioplasty success of 56.1% (41/73). Angioplasty success was reduced compared with crossing success in seven arteries in which complications occurred during balloon angioplasty. Multiple stepwise logistic regression analysis identified the location of the occlusion (right coronary artery, p = 0.005) as independent predictor of crossing success of this technique and the male gender (p = 0.03), the duration of occlusion (p = 0.05), the lesion length (p = 0.01) and the location of the occlusion (right coronary artery, p = 0.02) as independent predictors of final procedural success of the method.
Two-dimensional kinetic models for radiotherapy planning quality assurance.
Authors: Seaby A W , Thomas M
Published: June 2014

For treatment planning, the visualization of the direction and orientation of a beam, specified by a set of machine angles, can sometimes be very difficult. A set of simple two-dimensional kinetic models has been prepared. These show the angular and field conventions of the local linear accelerators.
A comparison of MRI and echocardiography in hypertrophic cardiomyopathy.
Authors: Devlin A M , Moore N R , Ostman-Smith I
Published: June 2014

This study compares MRI and echocardiography as imaging modalities in hypertrophic cardiomyopathy, with particular reference to measurement of left ventricular wall thickness and mass. 10 subjects underwent echocardiography and MRI. Contiguous 10 mm short axis 35 degrees flip angle cine gradient recalled echo MR images were acquired from the apex to the base of the left ventricle at 1.5 tesla. Standard M-mode and cross-sectional echocardiographic views of the left ventricle were obtained. Excellent agreement between measurements occurred with MRI and M-mode echocardiographic assessment of the thickness of the anterior interventricular septum (95% limits of agreement -1.5 to +1.5 mm). Other comparisons of MRI vs M-mode echocardiographic measurements had the following limits of agreement: posterior free wall -3.3 to +2.9 mm; end-diastolic dimension -5 to +8 mm, left ventricular mass -291 to +55.5 g. Comparing MRI with cross-sectional echocardiographic measurements, the limits of agreement were: anterior interventricular septum -2.4 to +1.7 mm, posterior interventricular septum -2.4 to +2.9 mm, posterior free wall -3.4 to +2.5 mm, anterior free wall -2.4 to +1.7 mm, end-diastolic dimension -4.1 to +8 mm. MRI estimates of LVM in systole vs diastole showed good agreement with 95% limits of agreement of -20 to +17 g, with excellent interobserver variability in diastole (-9 to +5 g) and in systole (-7 to +12 g). In conclusion, MRI is superior to echocardiography for the quantification of ventricular mass in the abnormal left ventricle because it does not make invalid geometrical assumptions. Comparisons of wall thickness show greater discrepancy with increasing distance from the echocardiographic transducer. This study suggests that sequential echocardiography could rationalize the need for MRI in left ventricular hypertrophy. A change in anterior septal thickness of > or = 3 mm on echocardiography merits a further MRI study.
Embolization of iatrogenic venous pseudoaneurysm.
Authors: Chakraborty S , McGann G , Coen L D
Published: June 2014

A case is described where a patient on long-term anticoagulation developed a venous pseudoaneurysm in the antecubital fossa following venepuncture. This venous pseudoaneurysm was successfully treated with coil embolization.
Variation between experienced observers in the interpretation of accident and emergency radiographs.
Authors: Robinson P J , Wilson D , Coral A , Murphy A , Verow P
Published: June 2014

Skill mix and role extension initiatives have highlighted the difficulty of establishing quality standards for the accuracy of plain film reporting. An acceptable performance might be one which is indistinguishable from that of a group of experienced consultant radiologists. In order to assess the feasibility of setting such a standard, the variation between experienced observers must first be established. This study examines the variation found between three observers with the three major types of plain film examination. 402 plain film examinations (205 skeletal, 100 chest and 97 abdominal) performed on accident and emergency patients were reported retrospectively and independently by three experienced radiologists. The clinical data supplied on the request cards were available to the readers. Each examination was categorized by each reader as being normal, as showing significant abnormality relevant to the current clinical problem, or as showing insignificant or irrelevant abnormality. Concordance between all three readers was found in 51%, 61% and 74% of abdominal, chest and skeletal radiographs, respectively. Weighted kappa values confirmed that the level of agreement between pairs of observers was higher with skeletal radiographs (kappa w = 0.76-0.77) than with chest (kappa w = 0.63-0.68), or abdominal (kappa w = 0.50-0.78) examinations. However, the frequency of major disagreements (at least one reader reporting "normal" and one reporting "relevant abnormality") was similar for abdominal (11%), chest (12%) and skeletal (10%) radiographs. When the reports were reclassified into only two groups--either significantly abnormal or not--pairs of observers disagreed on 9-10% of skeletal, 11-19% of chest and 8-18% of abdominal cases. The average incidence of errors per observer was estimated to be in the range 3-6%. The magnitude of interobserver variation in plain film reporting is considerable, and must be taken into account when designing assessment techniques and setting quality standards for this activity.
A radiographic method for assessing lung area in neonates.
Authors: Dimitriou G , Greenough A , Kavvadia V , Shute M , Karani J
Published: June 2014

The aim of this study was to determine whether computer assisted analysis of lung area on the chest radiograph reliably predicted lung volume in neonates. Anteroposterior chest radiographs taken for clinical purposes were scanned and analysed using a Power Macintosh computer with a Wacom A5 Ultra Pad and NIH image software. The cardiac, mediastinal and thymic densities and areas of perihilar and lobar consolidation were subtracted from the thoracic area to give the lung area. This was compared with lung volume, assessed by measurement of functional residual capacity (FRC), within 1 h of the chest radiograph being performed. 50 infants, median gestational age 30 weeks (range 24-43) were studied. Their median lung area was 11.23 cm2 (range 0.82-28.53) and lung volume 28 ml (range 3-103). The intraobserver and interobserver coefficients of repeatability of lung area were 1.0 cm2 and 1.06 cm2, respectively. Lung area correlated significantly with FRC (r = 0.60, p < 0.0001). It is concluded that computer assisted analysis of the chest radiograph lung area is a reliable method of assessing lung volume in neonates.
Pulmonary tuberculosis: radiological features in west Africans coinfected with HIV.
Authors: Lawn S D , Evans A J , Sedgwick P M , Acheampong J W
Published: June 2014

A retrospective study was performed to document and compare the radiological appearances of newly diagnosed pulmonary tuberculosis (PTB) in groups of West African patients with (n = 86) and without (n = 106) human immunodeficiency virus (HIV) coinfection. Analysis of chest radiographs showed that the HIV-positive group had less consolidation (mean 3.1 zones vs 3.7 zones; p < 0.05), less apical involvement (64.0% vs 85.5%; p < 0.001), less bronchopulmonary spread (27.9% vs 58.5%; p < 0.001), less volume loss (53.5% vs 76.4%; p < 0.001) and less pleural thickening (46.5% vs 61.3%; p < 0.05) compared with the HIV-negative group. However, HIV-positive patients more commonly had pleural effusions (17.4% vs 6.6%; p < 0.05) and lymphadenopathy (9.3% vs 1.9%; p < 0.05). Previous studies on this subject from sub-Saharan Africa have focused either on selected patient groups likely to have more advanced immunosuppression or on smear-positive cases only, or where there has been only limited radiological documentation. This study suggests that the highly significant differences that exist may not be as frequent as previously shown. The lower frequencies of bronchopulmonary pattern of consolidation and pleural thickening in HIV-positive subjects have not previously been documented. The possible reasons for the altered radiographic appearance of PTB in HIV positive subjects are discussed.