bluuebunny/crossref_metadata_2025 huggingface dataset:
Physical aspects of photostimulable phosphor computed radiography
Authors: Cowen A R , Workman A , Price J S
Published: July 2009

Currently photostimulable phosphor computed radiography (PPCR) promises to be the digital X-ray image acquisition technology of choice for classical radiography (i.e. X-ray examinations of natural anatomy). For the last two years we have been carrying out a physical evaluation of modern PPCR technology and some of our findings relevant to general radiographic applications are reviewed here. Topics covered include the function of the auto-reader system and the reliability of image reproduction, the radiation exposure requirement and physical image quality. The latter is based upon both objective and subjective measures of image quality. These studies have yielded a favourable comparison of the image quality of modern PPCR technology with that of medium-speed and fast radiographic screen-film combinations. The major advantages of PPCR appear to be the maintenance of high imaging efficiency (DQE) over a much wider range of signal levels than film and consistent image acquisition and presentation independent of exposure level. In general radiographic applications no major limitations due to the comparatively modest limiting spatial resolution of PPCR [maximum limiting resolution = 5 line-pair mm−1] have been experienced. Digital image enhancement is a central element of PPCR image reproduction. The authors believe that advances in image enhancement algorithms remain a potential area for further improving the presented quality of PPCR images.
Relationships between metacarpal morphometry, forearm and vertebral bone density and fractures in postmenopausal women
Authors: Wishart J M , Horowitz M , Bochner M , Need A G , Nordin B E C
Published: July 2009

The relationships between metacarpal morphometric, vertebral and forearm density measurements and the prevalence of vertebral and peripheral fractures were examined in 239 postmenopausal women (median age 63, range 32–84 years). Metacarpal cortical area/total area ratio (CA/TA) was measured with needle calipers, forearm mineral density (FMD) by single photon absorptiometry and vertebral mineral density (VMD) by single energy quantitative computed tomography. Of the 239 subjects 97 had not suffered any fractures, 44 had at least one previous vertebral fracture but no peripheral fractures, 41 had a history of peripheral fracture but no vertebral fracture and 57 had suffered both peripheral and vertebral fractures. There were significant correlations between a single measurement of CA/TA and both FMD (r = 0.65, p < 0.001) and VMD (r = 0.41, p < 0.001). Similar correlations existed between the mean of multiple measurements of CA/TA and both FMD and VMD. CA/TA (p < 0.001), FMD (p < 0.001) and VMD (p < 0.001) were reduced in subjects who had suffered fractures, when compared with the no fracture group. The percentage of cases in each of the four fracture groups (vertebral fracture only, peripheral fracture only, peripheral and vertebral fracture, peripheral or vertebral fracture) misclassified with reference to the no fracture group were similar with CA/TA, FMD or VMD measurements. We suggest that metacarpal morphometry, which is widely available at relatively low cost, yields cross-sectional information about bone density and fracture risk, comparable with that obtained by forearm and vertebral densitometry.
Book reviews
Authors: Faulkner K
Published: July 2009

All X-ray tubes contain some added filtration, usually in the form of aluminium for conventional radiology and molybdenum for mammography. The purpose of X-ray tube filtration is to remove selectively low energy X-ray photons from the X-ray spectrum.
Lingual thyroid, a cause of neonatal stridor
Authors: Chan F L , Low L C K , Yeung H W D , Saing H
Published: July 2009

Stridor implies partial airway obstruction, resulting from intrinsic or extrinsic abnormalities of the upper respiratory tract. In a neonate whose airway is small, soft and easily occluded this may be potentially life threatening. Its immediate diagnosis with prompt therapy is a rewarding challenge. When stridor occurs in a neonate with congenital hypothyroidism, surgically amenable cause of obstruction due to an ectopic thyroid or thyroglossal cyst has to be seriously considered. We report a case of neonatal stridor caused by a lingual thyroid, and discuss the imaging approach.
Chondrosarcoma of the epiglottis
Authors: Cheung W , Leong L L Y , Chan F L
Published: July 2009

Chondrosarcoma of the larynx is a rare lesion. We report a case of chondrosarcoma of the epiglottis, with a discussion on the diagnosis and treatment of this tumour.

A 34-year-old man, with previous good health, presented with a one-year history of hoarseness. Physical examination was normal and, in particular, there were no neck masses. Indirect laryngoscopy revealed a smooth mass arising from the laryngeal surface of the epiglottis, with intact mucosa.
Book reviews
Authors: Banerjee A K
Published: July 2009

Of all the radiology books published, few can claim to contain no examples of radiographs, ultrasound images, computed tomography (CT), magnetic resonance imaging (MRI) or nuclear medicine scans. This two volume, two author tome attempts to cover the subject of radiology without any “authentic” images. Although euphemistically titledOutline of Medical Imagingthe radiology trainee will find a wealth of detail within its 1300 pages.
Reproducibility of Doppler ultrasound measurement of resistance index in renal allografts
Authors: London N J , Aldoori M I , Lodge V G , Bates J A , Irving H C , Giles G R
Published: July 2009

In recent years measurements of arterial blood flow in the renal allograft have been studied in an attempt to provide a non-invasive method of diagnosing and monitoring post-transplant renal dysfunction. Many studies have involved measurement of the resistance index (RI) of arterial blood flow. Although the reproducibility of the technique has been studied in other areas of application, no such studies have been performed on the renal allograft. In this study we attempted to evaluate the reproducibility of the measurement of the RI of the interlobar artery in the renal allograft. 18 renal allograft recipients with stable functioning grafts were studied twice by each of two experienced sonographers using a colour-coded duplex Doppler ultrasound scanner, in order to determine the intraobserver and interobserver variability in the measurement of RI of the interlobar arteries in the allograft. Variability was small and although interobserver variability exceeded intraobserver variability, both were within repeatability limits adopted by the British Standards Institution. The results suggest that measurement of the RI of the interlobar artery of renal allografts is repeatable and reproducible when performed by experienced operators.
Spontaneous perforation of the common bile duct in infancy
Authors: Smethurst F A , CARTY H
Published: July 2009

Spontaneous perforation of the common bile duct in infancy is a rare disorder, but it is second to biliary atresia as a cause of surgical jaundice in the infant (Lilly et al, 1974). This diagnosis was made by ultrasound and scintigraphy in an infant presenting with failure to thrive, abdominal ascites and mild jaundice.

Conservative surgery with repair of the leak is the preferred treatment. The long term prognosis is excellent.
Congenital fistula between the submandibular gland and the oropharynx
Authors: McFerran D J , Phillips R R
Published: July 2009

Congenital salivary fistulae are rare and may be associated with abnormalities of the branchial apparatus or arise from aberrant or accessory salivary tissue. Previous case reports have documented cutaneous fistulae. We report a case of a salivary fistula between the submandibular gland and the oropharynx and discuss a possible embryological basis for the abnormality.
3-dimensional reconstruction of ultrasound images of the uterine cavity
Authors: Balen F G , Allen C M , Gardener J E , Siddle N C , Lees W R
Published: July 2009

We report our experience of 3-dimensional (3-D) reconstruction of ultrasound images of the uterine cavity. This is the first time that mapping of the contours of the uterine cavity with 3-D reconstruction has been achieved using standard clinical equipment for image acquisition. Ultrasound contrast hysterography was performed on 10 patients using both negative and positive intrauterine contrast media. 3-D image acquisition was performed during uterine cavity distension. The manipulation of the 3-D data sets is described and examples are shown. We believe that in some circumstances 3-D reconstructed images may be easier to interpret than 2-dimensional ultrasound images. We anticipate that this new technique will have a role in the preoperative assessment of uterine fibroids and endometrial polyps.
Book review
Authors: Green V S , Saunders A J S
Published: July 2009

There can be few ultrasound departments unacquainted with the first edition of this superb bench book for sonographers produced by Roger Sanders and his team of sonographers at the Johns Hopkins in Baltimore. It contains a wealth of straight factual information, but more importantly a host of practical tips and guides for separating the important diagnostic details from the background of “noise” of anatomical variation and artefact which form an inevitable part of an ultrasound scan.
Pseudo-tumour of the postero-superior mediastinum
Authors: Meaney J F M , Roberts D E , Carty H
Published: July 2009

A 6-month-old male child with known cystic fibrosis and a previously normal chest X-ray had a routine chest radiograph. What does it show? An ultrasound examination and enhanced computed tomography (CT) were also performed. Do these help?

What is the most likely diagnosis and what would you do next?

The chest X-ray revealed an opacity in the right upper mediastinum extending from the right hilum to the apex of the lung (Figure 1). There was no evidence of calcification or rib erosion. In view of a recent normal CXR a malignant neurogenic tumour was considered the most likely diagnosis. Serum and urinary catecholamines were normal. Atelectasis of the right upper lobe was considered unlikely on both clinical and radiological grounds and furthermore there was no change in the mass following physiotherapy and antibiotic treatment.
Book reviews
Authors: Gleeson J A
Published: July 2009

This book attempts, successfully, to act as an introductory text to contrast examinations of the gastrointestinal tract. There is limited space devoted to nuclear imaging and computed tomography whilst ultrasound is purposely excluded. The text is short but adequate; some of the illustrations could be improved by increasing the image size and by the inclusion of line drawings.
The patello-femoral joint—a critical appraisal of its geometric assessment utilizing conventional axial radiography and computed arthro-tomography
Authors: Walker C , Cassar-Pullicino V N , Vaisha R , McCall I W
Published: July 2009

In the quest for treatable causes of anterior knee pain, plain film skyline views of the patello-femoral joint are requested, often in 30°, 60° and 90° of flexion, to assess the functional relationships of the joint. Patello-femoral malalignment predisposes to recurrent subluxation and dislocation, articular cartilage damage and premature degenerative change. The aim of this study is to evaluate critically, by comparative assessment, the information provided by skyline views and axial computed arthro-tomography (CTA). Measurements of the patello-femoral angle (assesses patellar tilt), the congruence angle (assesses patellar lateralization) and the trochlear depth were made on Merchant's skyline views and on axial CTA on each of 50 symptomatic knees. Results are presented in graphic form with visual examples indicating a poor correlation between the two imaging methods. We conclude that skyline views are inaccurate and unsuitable primarily because they cannot be obtained in less than 30° of flexion. We suggest that skyline views have no role to play in screening for maltracking as even florid examples must be missed, and would strongly urge that no surgery be performed on their basis alone as this would result in inappropriate operations. Although computed tomography is the preferred mode of assessing patello-femoral geometry, difficulties are still encountered and the ways of circumventing them are discussed.
The histological response of the lungs of rats to potentially suitable water soluble bronchographic contrast agents iotrolan (a non-ionic dimer) and iopamidol (a non-ionic monomer)
Authors: Ginai A Z , Bubberman A , Zondervan P E , Van Leeuwen W , Morcos S K
Published: July 2009

The recent need for selective bronchography during bronchoscopy in certain patients, together with paediatric indications for tracheo-bronchography, raises the question as to which contrast medium is both safe and efficient. The purpose of the present experimental study was to define the tissue reaction caused by iotrolan and iopamidol in the bronchi and lungs of rats. 60 animals used in this study were divided into five groups receiving iotrolan 300, iopamidol 370, iopamidol 150, physiological saline and anaesthetic only, the last two acting as control groups. Statistically there was no significant difference in the histological reaction between iotrolan 300, iopamidol 370 and iopamidol 150 compared with the control groups, although iotrolan 300 appeared to result in the least tissue reaction. With its adequately high iodine concentration, low osmolality and relatively high viscosity, iotrolan 300 would appear to be a suitable contrast medium for bronchography.
T1ρ dispersion imaging of diseased muscle tissue
Authors: Lamminen A E , Tanttu J I , Sepponen R E , Pihko H , Korhola O A
Published: July 2009

T1ρ dispersion, or the frequency dependence of T1 relaxation in the rotating frame, was used for in vivo muscle tissue characterization in 13 patients with primary skeletal muscle disease and in eight normal subjects for comparison. T1ρ dispersion measurements represent a new approach to magnetic resonance tissue characterization, possibly reflecting the macromolecular constituents of tissue. A definite, statistically significant, difference was found between the relative T1ρ dispersion values of normal and diseased muscle tissue. T1ρ dispersion measurements and images may increase the accuracy of identification of diseased muscles. Early identification of affected muscles is important for accurate diagnosis by muscle biopsy.
Stab wounds of the heart: two new signs of pneumopericardium
Authors: Van Gelderen W F C
Published: July 2009

The diagnosis of a small traumatic pneumopericardium may be difficult and differentiation from a left medial pneumothorax or pneumomediastinum is important. Two new signs which only occur in pneumopericardium are described: the “transverse band of air” sign on the frontal radiograph representing air in the transverse sinus of the pericardium, and the “triangle of air” sign as noted on the lateral radiograph. If there is still doubt, a left-side-down decubitus radiograph will establish the diagnosis.
Book reviews
Authors: Duck F A
Published: July 2009

The present widespread use of Doppler colour imaging in ultrasonic clinics has occurred extraordinarily rapidly. As Dr Merritt tells us, less than 10 years has elapsed since the earliest systems were emerging as prototypes into American hospitals, and barely 5 years since colour Doppler was added to commercial duplex scanners. Now, a large proportion of District Hospitals have at least one colour Doppler ultrasound scanner, and many have several as the value of imaging functional blood flow becomes clearer.
Complications of intraarterial digital subtraction angiography in patients investigated for cerebral vascular disease
Authors: Warnock N G , Gandhi M R , Bergvall U , Powell T
Published: July 2009

395 patients (236 males, mean age 55.6 years: 159 females, mean age 52.2 years) with suspected transient ischaemic attacks or previous strokes underwent intraarterial digital subtraction angiography (IADSA) over a 3-year period ending in March 1991. All procedures were performed via the femoral approach and the majority consisted of arch studies followed by selective catheterization. 253 (64.1%) of the patients had extracranial vascular disease confirmed at angiography. A retrospective analysis of the patients' records was made to extract all possible complications. Complications were defined as any untoward symptoms or signs occurring within 48 h and which could have been related to the angiogram. Neurological complications occurred in 15 (3.89%) patients. 10 (2.5%) patients had transient complications which resolved completely within 24 h. In three (0.8%) patients the neurological deficit was reversible, recovering fully within 6 days. Two (0.52%) patients were left with residual disability from stroke at 10 days. The permanent neurological complication rate is in the lower range of the rates recorded in previous conventional angiographic studies. We conclude that IADSA is a relatively safe and reliable form of investigation in patients with suspected cerebral vascular disease.
Improving the evaluation of renal transplant collecting system dilatation by computerized ultrasound image digitization
Authors: Kashi S H , Romaniuk C , Sadek S A , Irving H C
Published: July 2009

43% of the renal allografts transplanted at our centre demonstrate pelvicalyceal dilatation on ultrasonography. However, only 6% of grafts are ultimately shown to be obstructed by antegrade pyelography. We have attempted to improve the specificity of ultrasonography by a quantitative analysis of 394 serial ultrasound studies from 150 renal transplant recipients. Representative images in the longitudinal and transverse axes were selected by a single observer for each of the studies and the outline of the kidney and its pelvicalyceal system was traced out. The images were then digitized using a Summagraphics tablet so that the length, width and area of the kidney and its pelvicalyceal system were calculated for each image. A step-wise discriminant analysis was performed which showed that the ratio of the area of the kidney to its pelvicalyceal area in both axes discriminated between normal, dilated but non-obstructed, and obstructed grafts. The median ratio of kidney to collecting system area in the obstructed grafts was 5.2 in the longitudinal and 4.4 in the transverse scan planes (vs median ratios of 32.8 and 22.0 for non-dilated grafts). Using canonical discriminant function, an index was derived which combines these ratios for the longitudinal and transverse images of the same kidney and this has further improved the diagnostic accuracy (median index of 2.45 in obstructed group vs –0.85 in non-dilated kidneys). This method improves upon the radiologist's report and identifies those grafts which require intervention.
Feasibility of patient immobilization for conventional cranial irradiation with a relocatable stereotactic frame
Authors: Laing R W , Thompson V , Warrington A P , Brada M
Published: July 2009

The precision of patient repositioning and the firmness of immobilization are among the major determinants of the accuracy of radiation treatment delivery. A relocatable Gill-Thomas localizer (GTL) developed for neurosurgery and stereotactic radiotherapy achieves highly accurate relocation and immobilization and has been used successfully for fractionated stereotactic radiotherapy of intracranial lesions. The feasibility of using GTL for immobilization in conventional fractionated external beam radiotherapy was assessed by comparison with conventional Cabulite shell head fixation. The GTL was well tolerated at the time of preparation and during a 5 week course of radiotherapy. The principal advantage was superior relocation accuracy maintained throughout the course of treatment, high precision of field set-up and markedly reduced production time. In addition the time taken to position the patient in the treatment room was also marginally shortened. GTL is therefore a feasible method of head fixation for conventional cranial irradiation providing patients have adequate dentition. With further development the relocatable method of immobilization originally designed for stereotactic radiotherapy may become the preferred technique particularly in situations where high accuracy is desirable, such as stereotactically guided conformal radiotherapy.
Organ absorbed doses in intraoral dental radiography
Authors: Lecomber A R , Faulkner K
Published: July 2009

A dental radiography unit operating at 70 kV (nominal) and 20 cm focus–skin distance was used to irradiate an anthropomorphic phantom loaded with lithium fluoride thermoluminescent dosemeters, in order to assess the variation in organ absorbed dose with intraoral periapical radiographic view. 14 views using the bisectingangle technique and four views using the paralleling technique were studied. The results are presented and the doses and dose distributions examined. Doses for the paralleling and bisecting-angle techniques are compared, and the effects of focus-skin distance and beam collimation upon patient dosimetry discussed. Sources of uncertainty in dental dosimetry studies using phantoms are also considered.
Book review
Authors: Castellano I A
Published: July 2009

In this report the NCRP has gathered together past surveys of diagnostic radiology practice in the US in order to assess in detail the magnitude of medical diagnostic exposure and dose over the period 1964 to 1986. Data has been collected for diagnostic radiology, dental radiography and diagnostic nuclear medicine.
Gallbladder perforation and bile leakage: diagnosis by colour Doppler sonography and percutaneous treatment
Authors: Longo J M , Bilbao J I , de Villa V H , Iglesias A , Pardo F , Cienfuegos J A
Published: July 2009

Nowadays, ultrasound examination is routinely utilized in the diagnosis of acute cholecystitis and its complications. Perforation of the gallbladder wall is usually suspected from indirect, non-specific sonographic findings, i.e. pericholecystic fluid collections, free peritoneal fluid, irregular gallbladder wall thickening, gallbladder distention, gallstones, coarse intracholecystic echogenic debris, and a complex mass in the gallbladder fossa (Forsberg et al, 1988; Chen et al, 1990). Sonographic visualization of the gallbladder perforation itself is rarely achieved (Chau et al, 1988; Takada et al, 1989; Chen et al, 1990). We report a case in which colour Doppler sonography allowed direct visualization of the biliary leakage across the gallbladder wall, thus providing the diagnosis. In addition, percutaneous catheter drainage of both the gallbladder and adjacent collection allowed the perforation to heal, hence avoiding surgery.
Malignant giant cell tumour of the pancreas presenting as a large pancreatic cyst
Authors: Scott R , Jersky J , Hariparsad G
Published: July 2009

Carcinoma of the pancreas is a common tumour. Histologically, the majority are adenocarcinomas of duct origin. Carcinomas of the pancreas containing giant cells are uncommon and those containing osteoclast-type tumour cells are very rare. We report a case of malignant giant cell tumour presenting as an extremely large, thin walled haemorrhagic cyst of the pancreas. This tumour is most unusual in that the wall is composed of multiple highly pleomorphic malignant-looking multinucleated giant cells as well as numerous osteoclast-like giant cells in a stroma of small spindle shaped mononuclear cells.
Cranial fasciitis in childhood
Authors: Hoeffel J C , Galloy M A , Palau R , Lascombes P , Floquet J
Published: July 2009

We present a case of cranial fasciitis with involvement of the cranial vault.
Hypomagnesaemia in a patient with acromesomelic dysplasia
Authors: Minty I L , Hall C M
Published: July 2009

Hypomagnesaemia and acromesomelic dwarfism are both rare inherited disorders. We report the first case of both these conditions occurring in the same patient. Our child and his family pedigree are further evidence that both these diseases are inherited as autosomal recessive conditions. There is no known association between these two diseases.
Uterine sarcomas: a review of the Edinburgh experience from 1974 to 1992
Authors: Tinkler S D , Cowie V J
Published: July 2009

A retrospective review of patients treated for a uterine sarcoma in Edinburgh from 1974 to 1992 has been performed. Clinical details at presentation, tumour pathology, treatment and the outcome of treatment were all recorded. 82 patients' case notes were reviewed. 54 patients had died and 28 were alive (mean follow-up period 80.3 months). 39 patients had a malignant mixed mesodermal tumour, 12 patients had an endometrial stromal sarcoma, and 27 had a leiomyosarcoma. Using a modified FIGO staging retrospectively, 41 patients had Stage 1 disease, two patients had Stage 2, 16 patients had Stage 3, and 13 patients had Stage 4 disease. Definitive treatment of total abdominal hysterectomy and bilateral salpingo-oophorectomy was used in 69 patients, with 35 of these patients also receiving post-operative radiotherapy to the pelvis. 13 patients did not undergo surgery. Five of these patients received radical radiotherapy, three patients received palliative radiotherapy, and five patients were not treated. The overall median survival is 15 months and the 5-year actuarial survival is 31%. 25 of the 26 surviving patients had Stage 1 disease at presentation. Post-operative pelvic radiotherapy did not influence either survival or local tumour control. 51 of the 54 patients who relapsed had evidence of distant metastases. We conclude that total abdominal hysterectomy and bilateral salpingo-oophorectomy remains the treatment of choice for uterine sarcomas.
Fast magnetic resonance angiography using turbo-FLASH sequences in advanced aortoiliac disease
Authors: Sivananthan U M , Ridgway J P , Bann K , Verma S P , Cullingworth J , Ward J , Rees M R
Published: July 2009

A prospective study using contrast enhanced turbo-FLASH (Fast Low-Angle Shot) magnetic resonance (MR) angiography was performed to assess the arterial anatomy in patients who had advanced atherosclerotic aortoiliac disease. This new imaging sequence was employed in 17 patients and the results were compared with conventional abdominal aortography. MR angiography accurately detected all aortic occlusions (3/3), their sites and their extent. All nine iliac occlusions were correctly identified (sensitivity 100%, specificity of 90%). The sensitivity was 100% for stenosis of 50% or greater in the abdominal aorta, and the iliac and common femoral arteries. The degree of stenosis was overgraded in 20 of 51 lesions (39.2%). Mild stenosis was overgraded as moderate stenosis in 10 and as severe stenosis in three. Moderate stenosis was overgraded as severe stenosis in four. None of the mild or moderate stenoses resulted in areas of signal voids suggestive of occlusions. Three severe stenoses were seen as areas of signal voids (two iliac, one femoral). In the eight patients who had in total 10 aneurysmal dilatations of the aorta or the iliac arteries, MR angiography was superior in demonstrating the true extent of the aneurysms. We conclude that turbo-FLASH MR angiography has the potential to be a useful non-invasive imaging technique for patients with advanced aortoiliac disease.
Computed tomography in sternocostoclavicular hyperostosis
Authors: Economou G , Jones P B B , Adams J E , Bernstein R M
Published: July 2009

Sternocostoclavicular hyperostosis is a rare but recognized entity characterized by new bone formation and ligamentous ossification which limits mobility of the sternoclavicular joints. Aetiology is obscure and debated. There may be considerable delay in establishing the diagnosis, even by specialists. In confirming the diagnosis plain radiography is of limited value but radionuclide bone scan and computed tomography (CT) may be helpful. Four cases are described to emphasize these points and illustrate the clinical and radiological features of the condition. High resolution CT with thin sections (5 mm or less) is the examination of choice for demonstrating the characteristic features and is essential if the condition is to be confirmed in its early stages when treatment might be more successful in delaying progression.
A comparison of reference bone mineral density measurements derived from two sources: referred and population based
Authors: Ryan P J , Spector T P , Blake G M , Doyle D V , Fogelman I
Published: July 2009

The construction of reference ranges for bone mineral density (BMD) is of importance when denning risk of osteoporosis in an individual. This study examined lumbar spine BMD from two different populations of women aged 40–69 years, both measured by dual X-ray absorptiometry (DXA) using Hologic QDR-1000 machines. Results were compared with the manufacturer's reference range. At one site (Centre 1) women were referred by general practitioners for BMD measurement to aid decisions regarding long term hormone replacement therapy (HRT). At the other (Centre 2), women were drawn from the age/sex register of a London general practice (population 11 000) and invited to attend a screening examination at their local hospital. The BMD for both groups did not differ significantly from the manufacturer's reference range. The BMD at Centre 1 was lower than Centre 2 by 0.0175 g cm−2 but this did not reach significance and after calibration of both DXA machines with a spine phantom the difference in BMD of the two groups was reduced to only 0.0034 g cm−2. Population based sampling carries no advantage over a GP referral based method for the construction of spinal BMD reference ranges. Although local BMD reference ranges may be required for sites outside the spine the comparable results in this study of the two UK reference ranges and those of the USA manufacturer suggest that local reference ranges for lumbar spine BMD using DXA may be unnecessary in the UK.
Monte Carlo study of grid performance in diagnostic radiology: factors which affect the selection of tube potential and grid ratio
Authors: Sandborg M , Dance D R , Carlsson G Alm , Persliden J
Published: July 2009

A Monte Carlo computational model has been developed for the study of the performance of anti-scatter grids in diagnostic radiology. It is used here to estimate the scatter in the image plane from soft tissue phantoms (representing the patient) and to calculate image contrast and the mean absorbed dose in the phantom. Different scattering conditions, representative of various examinations, have been investigated: adult lumbar spine; small field radiography and fluoroscopy; adult chest and paediatric pelvis and chest. For each scattering condition, the combinations of tube potential and grid ratio have been found which, for a well designed grid, result in the lowest mean absorbed dose in the phantom for a fixed contrast level. In examinations which generate large amounts of scatter, the use of high grid ratios in combination with high tube potentials is favourable with regard to both mean absorbed dose in the phantom and tube charge. When less scatter is generated, either the grid ratio or the tube potential can be varied to achieve the desired contrast level. High grid ratios require shorter exposure times, but need careful alignment in the beam to prevent primary radiation cut-off. It is shown that the air gap technique can be used to reduce patient dose in examinations with small amounts of scatter, but in combinations with a lower tube potential than when a grid is used.
A new method of quantification of the pulmonary regional distribution of aerosols using combined CT and SPECT and its application to nedocromil sodium administered by metered dose inhaler
Authors: Perring S , Summers Q , Fleming J S , Nassim M A , Holgate S T
Published: July 2009

Aerosols of nedocromil sodium labelled with 99Tcm were delivered on 20 separate occasions to healthy male volunteers. Planar and single photon emission computerized tomography (SPECT) gamma scintigraphy were immediately performed to assess the pulmonary regional distribution of delivered aerosol. On a separate occasion volunteers were imaged using X-ray computed tomography (CT). Alignment of SPECT and CT images was performed using marked anatomical features and the anterior and lateral skin outlines. CT images provided data for attenuation correction and were used to define the anatomical lung volume. Central to peripheral (CP) ratios of deposited activity were calculated from volumes of interest in coronal and transverse sections of the right lung. These were compared with CP ratios obtained from planar images obtained immediately following aerosol inhalation. Volumetric CP ratio correlated significantly with immediate planar CP ratio (p < 0.001). Analysis of deposition in the whole right lung was performed by separating the SPECT lung data into a series of thin concentric shells centred on the entry of the right main bronchus. Measures were defined for describing the variation of deposition density and cumulative total deposition with distance from the lung centre. These showed significant correlation with planar CP ratio (p < 0.001). SPECT analysis using CT is consistent with planar measures of aerosol deposition but offers a more complete quantification of aerosol penetration and absolute deposited activity within the whole lung. It is a valuable new tool for aerosol analysis.
Errors in dual-energy X-ray absorptiometry of the lumbar spine owing to fat distribution and soft tissue thickness during weight change
Authors: Tothill P , Avenell A
Published: July 2009

It has previously been shown that the non-uniform distribution of fat leads to errors in the determination of spine bone mineral. If the fat error changes during alterations of weight, conclusions about bone mineral measurements might be compromised. To test this possibility, the distribution of adipose tissue was determined from X-ray CT scans taken for diagnostic purposes from patients whose weight had increased or decreased due to disease or treatment. For AP scanning the change in mean fat thickness over the vertebrae was similar to that in the background area, so that there was little change in fat error and therefore no misinterpretation of bone mineral measurements. Results were more variable for lateral scanning, sufficiently so as to question its validity in this context.

The dependence of bone mineral measurements on the soft tissue thickness was investigated with three different makes of dual-energy X-ray absorptiometer and four spine models. A complex dependence was found, which varied with the bone mineral density, the thickness, the machine and the model. However, the magnitude of the dependence was not sufficient to falsify the conclusions about changes in bone mineral in two clinical studies in which patients had changed weight.
Monte Carlo study of grid performance in diagnostic radiology: task dependent optimization for screen–film imaging
Authors: Sandborg M , Dance D R , Carlsson G Alm , Persliden J
Published: July 2009

An optimization of anti-scatter grid design using Monte Carlo techniques in diagnostic radiology is presented. The criterion for optimization was to find the combinations of the grid parameters (lead strip width, grid ratio and strip density) and tube potential which result in the lowest mean absorbed dose in the patient at fixed image contrast. The optimization was performed in three irradiation geometries, representing different scattering conditions (paediatric examinations, and two adult lumbar spine examinations) and was restricted to grids using fibre materials in covers and interspaces. Grid designs currently available were studied, as were designs which use thinner strips (< 30 μm) and higher grid ratios (> 18). It was found that grids with widely different strip densities (strips cm−1) and grid ratios can have good performance provided that they are used with appropriate strip width and tube potential. With increasing amounts of scatter, the optimal grid requires thicker strips and higher grid ratios. Increasing the strip density and using thinner strips and higher grid ratios are generally required. Grids with low strip density (25 strips cm−1) were found to be less sensitive to alterations in strip width. Optimal grids for paediatric radiology require thinner strips (10–20 μm) than those in currently available grids. Grids on the market are best suited for examinations of the adult body in anteroposterior (AP) view. In the adult lateral view, representing the largest scattering volume, higher grid ratios (> 18) than those in existing grids would be optimal. Examples of good grid designs are given for each examination.
Computed tomography findings in lipoid proteinosis: report of two cases
Authors: Özbek S S , Akyar S , Turgay M
Published: July 2009

Lipoid proteinosis (Urbach–Wiethe disease (Urbach, E and Wiethe, C, Lipoidosis cutis mucosae, Virchows Arch. Patholog. Anat., 273, 285–319 (1929)) is a rare generalized disease with autosomal recessive inheritance. It most often involves the skin and mucosal membranes of the aerodigestive tract; but also involves the central nervous system, lung, lymph nodes and striated muscles. We present the computed tomography findings in the cranium and larynx of two siblings with lipoid proteinosis.
Unusual ultrasonographic appearance of a solitary retroperitoneal neurofibroma
Authors: Tsai Chung-Jyi
Published: July 2009

A neurofibroma in the retroperitoneum with unusual ultrasonic findings is described. The ultrasonographic differential diagnosis with other abdominal neoplasms, clinical features and pathological findings are presented.
The value of the short tau inversion recovery sequence in magnetic resonance imaging of thyroid eye disease
Authors: Laitt R D , Hoh B , Wakeley C , Kabala J , Harrad R , Potts M , Goddard P
Published: July 2009

22 patients with thyroid eye disease were examined with magnetic resonance imaging (MRI) and the results compared with 10 controls. Imaging was performed on a 1.0 T scanner using a head coil. All patients were examined using both T1W and short tau inversion recovery (STIR) sequences. The relative signal intensity (SI) of individual extraocular muscles were quantified by comparison with SI from the adjacent temporalis muscle to give a signal intensity ratio (SIR). The results were compared with clinical disease activity assessed by the Werner grading system. Visual evaluation of muscle size and calculated SIRs showed an increase when compared to normals in 15 of the 22 patients. This difference was significant in patients with high grade (4–6) clinical disease. The known histological changes in this disease suggest that this increase in signal is caused by oedema secondary to acute inflammation. STIR sequences suppress the retro-orbital fat and thus enhance these changes both in the muscles and in the fat itself. The MR findings suggest that the STIR sequence can be used to predict those patients that will respond to anti-antiflammatory treatment.
The value of shoulder distension arthrography with intraarticular injection of steroid and local anaesthetic: a follow-up study
Authors: Mulcahy K A , Baxter A D , Oni O O A , Finlay D
Published: July 2009

A series of 51 patients, seen in Leicester, with “frozen shoulder”, and referred for arthrographic examination, were assessed both before and after distension arthrography, using air and a low-osmolar contrast media combined with a steroid and local anaesthetic injection. 38 attended for further assessment at up to 6 months later. 16 patients were found to have a rotator cuff tear. There was no significant change in the mean range of active movement in the patients with rotator cuff tears, but symptomatic improvement ensued in 44% of cases. In those found to have no rotator cuff tear, and external rotation of less than 35°, a significant improvement in range of movement was seen. While those with less limitation of external rotation showed no change in their range of movement, they did experience symptomatic improvement in 73% of cases. We conclude that shoulder distension arthrography, with steroid and local anaesthetic injection, may be of symptomatic benefit in patients with frozen shoulder and without a rotator cuff tear, while only those with external rotation of less than 35° are likely to improve their range of motion.
EMI patent litigation in the US
Authors: Cormack A M
Published: July 2009

Having observed a little bit of the EMI patent litigation in the United States from a somewhat different perspective I would like to comment on the above letter by Strong and Hurst.

The paragraph about EMI's willingness to grant patent licences being inhibited by fear of a Declamatory Judgement seems unfair to the US District Courts as well as perhaps being disingenuous.
Magnetic resonance imaging appearances of fatigue fractures of the long bones of the lower limb
Authors: Tyrrell P N M , Davies A M
Published: July 2009

Fatigue fractures may be confused with malignant bone lesions on radiography and hence are periodically referred for further imaging assessment with computed tomography (CT) and magnetic resonance imaging (MRI). The appearances on MRI are characteristic although not pathognomonic. Typical findings include: intramedullary bands of low signal intensity, continuous at some point with the cortex, indicative of a fracture line; intramedullary areas of high signal on both T2-weighted and short-t inversion recovery (STIR) images representing marrow oedema or haemorrhage, together with evidence of periosteal oedema. We present seven cases of fatigue fractures of the long bones of the lower limb and discuss the MRI findings and compare CT and MRI in imaging these lesions.
Magnetic resonance imaging of transfusional hepatic iron overload
Authors: Bondestam S , Lamminen A , Anttila V-J , Ruutu T , Ruutu P
Published: July 2009

The transfusional iron overload in 11 adult patients suffering from haematological malignancy was studied in 14 consecutive 1.0 Tesla magnetic resonance imaging (MRI) studies. Routine T  1- and T  2-weighted spin echo sequences and a fat suppressed sequence (STIR) were used. The ratio from a region of interest of the liver parenchyma and from a manganese chloride reference phantom was measured. There was a definite difference between the signal ratio from the haematological patient group and the control group (p = 0.0001). The patients showed a diminished signal ratio in all pulse sequences used. There was a statistically significant inverse linear correlation between the number of transfused red cell units and the signal ratio in the T  2,-weighted (p = 0.03) and the T  2-weighted (p = 0.03) images. A definite decrease of the effect is found after 20–30 red cell unit transfusions in T  2-weighted and STIR images.
Intraperitoneal metastases from testicular germ cell tumour
Authors: Heafield R J , Mead G M , Tung K T
Published: July 2009

We report a patient with intraperitoneal metastases following treatment for seminoma. This is an unusual site of spread and was accompanied by transformation of tumour morphology.
Magnetic resonance imaging for volume estimation of large multinodular goitres: a comparison with scintigraphy
Authors: Huysmans D A K C , De Haas M M , Van Den Broek W J M , Hermus A R M M , Barentsz J O , Corstens F H M , Ruijs S H J
Published: July 2009

As a result of increasing interest in non-surgical treatment for the reduction of goitre size the use of magnetic resonance (MR) imaging for volume estimation of large multinodular goitres was evaluated in 20 patients (three males and 17 females; age 61 ± 21 years) with a multinodular goitre larger than 100 ml. In addition, MR measurements were compared with scintigraphic (SC) volume estimations. Intraobserver coefficient of variation (CV) of MR measurements was 2.2 ± 2.0% (Observer 1) and interobserver CV 4.1 ± 2.2% (Observers 1 and 2). In all 20 patients signs of mechanical complications were shown on MR images. For SC measurements intraobserver CV was 7.5 ± 5.7% (Observer 3) and 5.4 ± 5.1% (Observer 4). Interobserver CV was 10.1 ± 6.1%. The correlation between measurements with both methods was not strong (r = 0.665) and the resulting CV was 17.3 ± 14.2%. Underestimation of SC volumes could not be explained by the presence of cysts on the surface of the thyroid. It is concluded that MR imaging can be used for in vivo thyroid volume estimation in large multinodular goitres. The high precision of MR measurements makes this technique potentially useful for the evaluation of thyroid growth and non-surgical treatment for reducing goitre size. Scintigraphic volume measurements do not suffice for this purpose. An additional advantage of MR imaging is the detailed anatomical information it provides with regard to mechanical complications of large goitres.
Digital sialography: imaging and intervention
Authors: Buckenham T M , George C D , McVicar D , Moody A R , Coles G S
Published: July 2009

Digital subtraction imaging (DSI) has been widely used in angiography but less commonly applied to sialography. Over a 3-year period 109 patients referred for sialography, 42 males and 67 females with a mean age of 44 years (range 8–85 years), were examined using a digital subtraction imaging technique. 13 patients went on to have an interventional procedure, stone removal or duct dilatation. The role of DSI imaging in sialography and its use in facilitating interventional procedures on the salivary glands are discussed.
99Tcm-HMPAO cerebral scintigraphy and transcranial pulsed Doppler in acute intracranial hypertension in rabbits
Authors: De Bray J M , Le Jeune J , Pourcelot L , Saumet J L , Jallet P
Published: July 2009

The purpose of this study was to compare transcranial Doppler sonography (TCD) and 99Tcm-HMPAO cerebral scintigraphy in detecting the effects of acute intracranial hypertension by pressure transmission using a previously validated model. In 20 New Zealand rabbits, cerebral blood flow velocities of basilar artery and carotid siphon were simultaneously monitored in baseline conditions and during acute intracranial hypertension by pressure transmission. This hypertension was induced by progressive steps of 5 mmHg, for a 5 min duration by elevating a saline infusion bottle connected to the subdural space. In baseline conditions, significant correlations were found between basilar artery resistive index and 99Tcm-HMPAO uptake in brain stem, r = 0.5 (p < 0.05) and posterior cerebral areas, r = 0.78 (p < 0.001). Severe intracranial hypertension equal to the diastolic arterial pressure with a cerebral perfusion pressure of 22.8 ± 12.7 mmHg significantly decreased the basilar artery blood flow velocities and global 99Tcm-HMPAO cerebral uptake. At this level of intracranial pressure, few correlations between the two methods were observed. TCD detected relatively high blood-flow velocities in the carotid siphon appearing to result from proximal cerebral artery vasospasm. Transcranial pulsed Doppler provides data about haemodynamic changes such as hypoperfusion, vascular resistance increase in the basilar artery territory and vasospasm of the carotid siphon. 99Tcm-HMPAO scintigraphy, which has not yet been studied during intracranial hypertension, gave immediate information on local cerebral perfusion. Cerebral scintigraphy demonstrated a significant diffuse and heterogeneous decrease in cerebral blood flow, without dissociation between supratentorial and infratentorial territories, and tissue perfusion deficit owing to arterial vasospasm. TCD provides emergency investigation in patients with severe head injuries or hydrocephalus. 99Tcm-HMPAO complements TCD in cases of vasospasm and in determining an area of perfusion tissue deficit.
Ciliated foregut cyst of the pancreas mimicking teratomatous tumour
Authors: Kohzaki S , Fukuda T , Fujimoto T , Hirao K , Matsunaga N , Hayashi K , Irie J , Kondo N
Published: July 2009

A ciliated cyst of foregut origin is often found in relation to the tracheobronchial tree and the upper gastrointestinal tract, when it is called bronchogenic cyst and enterogenous cyst, respectively. Cysts of this type rarely occur in the pancreas. We report a case of ciliated foregut cyst involving the pancreas, and mimicking teratomatous tumour on radiology.