bluuebunny/crossref_metadata_2025 huggingface dataset:
Intrarenal Doppler ultrasound studies in normal and acutely obstructed kidneys
Authors: Rodgers P. M. , Bates J. A. , Irving H. C.
Published: July 2009

Renal ultrasound examinations and intrarenal arterial Doppler studies were performed on 48 patients with normal renal tracts and 20 patients presenting with acute renal colic resulting from ureteric calculus, 14 of whom had urographic evidence of renal obstruction. The mean resistance index (RI) of the Doppler waveforms obtained on the 14 obstructed kidneys (70.4 ± 6.22) was significantly higher than the mean RI of the 96 normal kidneys (62.4 ± 6.43). The mean difference between the RIs of the obstructed kidneys and their contralateral non-obstructed kidneys (8.37 ± 4.43) was also significantly higher than the differences in RI seen between pairs of normal kidneys (2.70 ± 1.71). Five out of 14 obstructed kidneys showed no pelvicalyceal dilatation and could not have been shown to be obstructed on conventional sonography. Four of these five had RI changes suggestive of obstruction and thus 13 of 14 obstructed kidneys would have been identified as obstructed by a combination of Doppler and conventional sonographic findings. 10 of the 14 obstructed kidneys were re-examined after passage of a urinary calculus and nine showed a reduction in the RI of the previously obstructed kidneys. The 10th subsequently required ureterolithotomy.
Dose reduction by the use of erbium filtration in a general radiographic room
Authors: Cranage R. W. , Howard C. J. , Welsh A. D.
Published: July 2009

The conventional aluminium filtration of a general purpose X-ray tube in a district general hospital was replaced by an erbium filter for a 2-month period. The resulting reduction in skin dose was measured for a number of examinations using thermoluminescent dosimetry. The change in effective dose equivalent was calculated from these measurements and compared with previous theoretical estimates. The use of the erbium filter had no effect on radiograph quality. It was concluded that the use of an erbium filter resulted in a worthwhile reduction in radiation dose, and was a cost-effective method of dose reduction.
Magnetic resonance imaging and treatment of an unusual seminoma metastasis occurring in the parasellar region
Authors: Guy R. L. , Mason M. , Van Rensburg L. Janse
Published: July 2009

Seminoma of the testis is a relatively common tumour in young men and its typical pattern of spread is well documented. We describe an unusual case of a right parasellar seminoma metastasis presenting with partial fifth and sixth cranial nerve palsies. The appearances of the tumour on magnetic resonance imaging (MRI) and the current treatment for metastatic seminoma are discussed.

A 32-year-old man presented with a right testicular mass and underwent a right orchidectomy. Histology showed the testis to be replaced by a combined malignant teratoma undifferentiated and a classical seminoma. Staging investigations showed involvement of right iliac lymph nodes. The patient was treated with five courses of combination chemotherapy with vincristine, methotrexate, cisplatinum and bleomycin alternating with etoposide, actinomycin D and cyclophosphamide (POMB/ ACE), following which he was in complete remission as judged by lymphography.
Book reviews
Authors: Colquhoun I. R.
Published: July 2009

This is a well presented quality hardback edition of 497 pages. There are copious illustrations, the majority of which are of a high standard together with many useful lists and tables; these features together with the lucid text make this an interesting and enjoyable book.

In the preface the author states his intention to provide an in-depth discussion of the basic principles of neurodiagnosis. As the number and complexity of the available imaging techniques has so rapidly increased over the past few years this is an increasingly difficult task to undertake, especially in less than 500 pages.
Intramuscular myxoma: magnetic resonance features
Authors: Abdelwahab Abrahim Fikry , Kenan Samuel , Hermann George , Lewis Michael M. , Klein Michael J.
Published: July 2009

Magnetic resonance imaging (MRI) was performed in six cases of intramuscular myxoma of the extremities and revealed the following characteristics. All tumours were confined to muscle and had a sharply defined border. All had a signal intensity lower than skeletal muscles on T  1-weighted images and brighter than fat on T  2-weighted images. The signals were homogeneous on both T  1 and T  2-weighted images. This study did not include contrast enhancement. The diagnosis was confirmed by an open biopsy. All tumours were resected with no recurrence. Diagnosis based on these MRI characteristics was incorrect in two cases of intramuscular ganglia and in a case of intramuscular cysticercus cellulose. MRI features of intramuscular myxoma are typical in the majority of cases. Benign intramuscular lesions that contain mainly fluid can mimic intramuscular myxomas.
Contralateral thinking
Authors: Mehta S. , Whitehouse R.
Published: July 2009

A 23-year-old man presented to a sports injury clinic with a 6 month history of exercise induced low back pain with radiation to his right buttock. 18 months previously he had been treated for osteomyelitis of the right medial malleolus. On examination there was no neurological deficit. Initial investigations consisted of antero-posterior (AP) and lateral lumbar spine films (Fig. 1) and a 99Tcm HDP bone scan (Fig. 2). Haematological and biochemical investigations were normal.
Mistaken hilar mass
Authors: Wright F. W.
Published: July 2009

R. Thomas discusses the possibility of hilar enlargement due to a dilated oesophagus on a supine radiograph taken on a radiotherapy simulator apparatus and states that this is “well known”!

Two radiographs, one supine and one in the erect position were published with his letter to “prove” the point.
Measurement of tissue perfusion by dynamic computed tomography
Authors: Miles K.A.
Published: July 2009

I am most grateful for the references S. Rees has supplied on the measurement of blood flow using computed tomography (CT) in response to my paper (Miles, 1991). My comment in the discussion should have stated that absolute values for tissue perfusion from CT have not been reported previously in man.
The ultrasound appearances of intramural bowel gas: the bright ring appearance and the effervescent bowel. A report of three cases
Authors: Bloom Ronald A. , Craciun Eli , Lebensart Pinchus D. , Levy Pavel , Ziv Jacob Bar
Published: July 2009

Bowel necrosis is a serious condition with a very high mortality rate. The earlier the diagnosis is made, the better chance for survival. Ultrasound is a primary imaging technique in the diagnosis of the acute abdomen. Three cases are presented in which bowel wall gas could be demonstrated on ultrasound. In all cases there was computed tomographic and either operative or post-mortem correlation. In each case there was a “bright ring” appearance of the affected bowel when the ultrasound examination was carried out in transverse section. In one case, small bubbles were seen arising from the deep surface of the bowel.
The thread and streak sign of portal vein tumour thrombus demonstrated by colour Doppler imaging
Authors: McBride K. , Masterson J.
Published: July 2009

The angiographic, computed tomographic (CT) and real-time ultrasound demonstration of portal vein invasion and tumour thrombus is well documented, particularly in association with hepatocellular carcinoma (Gregg et al, 1975; Miller & Thomas, 1979; Freeny, 1980). One sign of portal vein tumour thrombus is the “thread and streak” sign first described angiographically in 1975 (Okuda et al, 1975). In this paper, we describe an unusual case of portal vein tumour thrombus first suspected by colour Doppler imaging (CDI). There have been no previously documented cases to show the thread and streak sign using this technique.

A 73-year-old man presented with a 4-month history of back pain, anorexia, weight loss and dyspnoea. He had a history of left pneumonectomy for squamous cell carcinoma of the bronchus 12 years previously, and a more recent history of drainage of left empyema 9 months earlier.
What is the clinical disadvantage of discarding old radiographs? Survey of patients not re-examined for a long time
Authors: Oyama Y. , Imamura K. , Ashida H. , Nakajima Y. , Itoh T. , Saeki M. , Kikuchi Y. , Matsumoto H. , Ishikawa T.
Published: July 2009

The clinical disadvantage of discarding old radiographs was evaluated in patients who had not been re-examined for more than 8 years after their last radiological examination, 38 772 in total. During the 1 year survey, 158 (0.41%) of them underwent re-examination after a long interval. Retrospective evaluation revealed that in only 12 patients (0.032%) were the old films useful. This survey suggested that the clinical risk of not referring to films more than 8 years old would be less than 0.049%. We consider this acceptable, and have formulated new guidelines of storage of films.
Gadolinium-DTPA enhanced MRI in neonatal osteomyelitis of the cervical spine
Authors: Martijn A. , van der Vliet A. M. , van Waarde W. M. , van Aalderen W. M. C.
Published: July 2009

Although the radiographic features of neonatal osteomyelitis are well described, spinal localizations are very rare and occur in about 2–4%. Clinical presentation with paresis and paralysis occurs in less than 1% (Resnick & Niwayama, 1988). In the neonate negative bone scintigraphy in the presence of bony destruction is not inconsistent with osteomyelitis as in the presented case (Swischuk, 1989). Magnetic resonance imaging (MRI) reports of these cases are scarce (Lac et al, 1990) and Gadolinium-DTPA enhanced MRI has not yet been described. Our recent experience with this unusual but characteristic presentation prompted this report.
Patellar metastasis: a rare presentation
Authors: Sur R. K. , Singh D. P. , Dhillon M. S. , Gupta B. D. , Murali B. , Sidhu R.
Published: July 2009

Primary patellar neoplasms are uncommon and metastasis to the patella is rarer still. Very few reports have been published in the literature (Stoler & Staple, 1969; Keeley, 1973; Gall et al, 1974; Ashby & Dappen, 1976; Hussey, 1976; Kwa & Nade, 1989). We present a case of primary bronchogenic carcinoma presenting as a huge swelling around the knee owing to a metastatic lesion in the patella.
Renal ultrasonographic appearances at presentation in an infant with Lesch-Nyhan syndrome
Authors: Ludman C. N. , Dicks-Mireaux C. , Saunders A. J.
Published: July 2009

Lesch-Nyhan syndrome, first described in 1964, is an X-linked recessive disorder of purine metabolism. A cellular deficiency or absence of the purine salvage enzyme hypoguanine phosphoribosyl transferase causes purine overproduction and subsequent hyperuricaemia and gout. Clinically the syndrome manifests as neurological disorders, behavioural disturbances characterized by self mutilation and variable mental retardation. In addition, hyperuricaemia results in the clinical features of gout, with gouty arthritis, tophi, urate and uric acid nephropathies.
How frequent is chronic lumbar arachnoiditis following intrathecal Myodil?
Authors: Hughes D. G. , Isherwood I.
Published: July 2009

Chronic lumbar arachnoiditis has numerous causes, including the introduction of contrast media into the lumbar subarachnoid space. The oily contrast medium Myodil (iophendylate) is often cited but the true incidence of symptomatic lumbar arachnoiditis due solely to the presence of Myodil is unknown. A retrospective review of 98 patients in whom Myodil was introduced by ventriculography or cisternography, i.e. remote from the lumbar spine, revealed no cases of chronic lumbar arachnoiditis. All patients were monitored closely for periods ranging from 1 to 28 years. We conclude that, in these circumstances, it is rare for Myodil to produce symptomatic arachnoiditis.
The prognostic importance of CT features in primary intracranial lymphoma
Authors: Namasivayam J. , Teasdale E.
Published: July 2009

The correlation of computerized tomography (CT) features with survival of 28 patients with primary intracranial lymphoma was analysed retrospectively. Severe perifocal oedema, periventricular tumours and lesions which were nonhomogenously enhancing or non-enhancing were found to be associated with a poor prognosis. The prognosis when multiple lesions were present was almost the same as that of a solitary lesion (p = 0.95). Ring enhancing lesions had considerably longer survival. Lesions in the frontal region and those close to the meninges, enhancing homogeneously, had a better prognosis.
Transverse geniculate ligament of the knee: appearance and frequency on plain radiographs
Authors: Sintzoff Serge A. , Stallenberg Bernard , Gillard Isabelle , Gevenois Pierre A. , Matos Celso , Struyven Julien
Published: July 2009

The aims of the study were to determine the frequency of visualization of the normal transverse geniculate ligament (TGL) of the knee on lateral plain radiographs with magnetic resonance imaging (MRI) as a reference, and to determine features that make this ligament apparent on plain radiographs. 50 consecutive lateral plain radiographs and sagittal T1-weighted images of corresponding knees were evaluated prospectively. A TGL was considered visualized on plain radiographs when an opacity of soft-tissue density was apparent in the posterior part of the Hoffa's fat pad. The TGL was identified in 29 of the 50 (58%) sagittal MR images; a TGL was observed on the lateral plain radiographs of six patients (12%). Correlation with the MR images showed that, when visualized on plain radiographs, the ligament is at least 3 mm thick and completely surrounded by fat. Our study shows that the TGL is a normal variant that can be recognized frequently on lateral plain radiographs of the knee.
Digital cardiac imaging—the death knell of cineangiography?
Authors: Dyet J. F. , Hartley W. , Cowen A. R. , Aber C. P.
Published: July 2009

Digital X-ray imaging techniques have achieved wide-spread acclaim in general vascular diagnosis and in the support of interventional procedures. However, in cardiac angiography, acceptability of digital imaging until recently, has been less enthusiastic. To a large extent this has reflected the effectiveness of cine fluorography and the exacting performance standards that it sets to any competing technique. Whereas cine fluorography provides rapid acquisition of dynamic sequences of high (spatio-temporal) fidelty images, the review of these images has to be retrospective and in practice it is necessary to rely heavily on the modest image quality provided by TV fluoroscopy for the on-line evaluation of the procedure.

Early attempts at digital cardiac imaging based upon digital subtraction angiography (DSA) produced results of widely inconsistent quality. This was partly because of the inferior specification of the equipment used at that time. In addition, however, the dynamic nature of the heart itself sets limits to the precision with which subtractive imaging could be performed. Nonsubtractive, or grey-scale, digital imaging on the other hand promised several practical advantages over DSA for cardiac studies, provided that the quality of the images could be enhanced using digital imaging techniques (Rouse et al, 1986).

The recent introduction of extremely fast but economical analogue to digital converters and microprocessors now means that the contest between digital and cine fluorography in cardiac imaging can begin in earnest. Viable digital imaging systems which are custom designed for cardiac applications are now available.
Single- versus dual-energy quantitative computed tomography for spinal densitometry in patients with rheumatoid arthritis
Authors: Laan Roland F. J. M. , van Erning Leon J. Th. O. , Lemmens J. Albert M. , van de Putte Levinus B. A. , Ruijs Sjef H. J. , van Riel Piet L. C. M.
Published: July 2009

Lumbar bone mineral density was measured by both single- and dual-energy quantitative computed tomography in 109 patients with rheumatoid arthritis. The results were corrected for the age-related increase in vertebral fat content by converting them to percentages of expected densities, using sex and energy-level specific regression equations obtained in a normal reference population. The percentages of expected density are approximately 10% lower in the single- than in the dual-energy mode, both in the patients with and without prednisone therapy. This difference is statistically highly significant, and is positively correlated with the duration of the disease and with the degree of radiological joint destruction. The data suggest that the vertebral fat content may be increased in patients with rheumatoid arthritis, as a consequence of disease-dependent mechanisms.
Single energy quantitative computed tomography: the effects of phantom calibration material and kVp on QCT bone densitometry
Authors: Whitehouse R. W. , Adams J. E.
Published: July 2009

Bone mineral densitometry by quantitative computed tomography (QCT) was introduced in 1976 (Isherwood et al 1976), and is now a clinically established and useful technique. It is usually performed with a reference phantom scanned with the patient. The reference phantom is required to correct for variations that may occur in measured CT numbers due to CT scale drifts or changes in effective beam energy (Cann and Genant 1980). The measured CT number in a region of interest is expressed in mineral density equivalents of phantom reference material.

A saturated solution of dipotassium hydrogen phosphate (K2HPO4) in water has been used in dosimetry as a cortical bone equivalent material for many years (Witt and Cameron, 1969) and dilutions of this material are popular for QCT reference phantoms used in trabecular bone mineral densitometry (Cann and Genant, 1980). Several potential sources of error have been identified with reference phantoms containing aqueous solutions of K2HPO4, including changes in concentration of the solute with time and displacement effects (Rao et al, 1987). These problems have stimulated searches for alternative reference materials, the most popular of which has been calcium hydroxyapatite. This has been regarded as preferable to K2HPO4 as calcium hydroxyapatite is a true constituent of bone. Calcium hydroxyapatite is not water soluble and has to be embedded in a water equivalent plastic. The attenuations of K2HPO4 and calcium hydroxyapatite alter with X-ray energy in similar, but not identical, rates to that of bone (Hubbell, 1969; ICRU, 1989).
Efficiency of a lead-containing tie for radiation protection of the thyroid gland
Authors: Klein Hans-Martin , Stargardt Achim
Published: July 2009

During fluoroscopy the examiner is usually protected by a radiation-reducing body shield, leaving the thyroid unprotected. The fact that the thyroid is located in a region of the neck usually covered by the shirt collar led to the idea of designing a tie with lead core, providing easy and “decorative” reduction of the radiation dose. Sonographic examinations were carried out in 20 volunteers (10 men, 10 women) to determine the size of the gland and its coverage by such a tie. The reduction of the surface and organ dose was assessed using film dosimetry with scattered radiation, the body of the examiner being simulated by an Alderson phantom. On average 88% of the thyroid gland surface area was covered. Surface dose was reduced to 1%, and organ dose to 10% of the value without the protection tie.
Effect of diatrizoate on the function of the isolated perfused rat kidney
Authors: Brownd P. , Haylor J. , Morcos S. K. , Cope G. H. , El Nahas A. M.
Published: July 2009

The mechanism of the nephrotoxicity of water-soluble contrast media (WSCM) remains ill denned. We have studied the effect of diatrizoate on the isolated perfused rat kidney (IPRK). Emphasis was on the effect of low- and high-dose diatrizoate on glomerular filtration rate (GFR), renal perfusate flow (RPF), fractional excretion of albumin (FE Alb) and fractional reabsorption of sodium (FR Na). The addition of diatrizoate to the IPRK led to a dose-dependent biphasic change in RPF and GFR characterized by an initial transient increase followed by a marked and sustained decrease. Diatrizoate induced a diuresis and a parallel increase in urinary sodium excretion (fall of FR Na). FE Alb was also increased in kidneys exposed to diatrizoate. Electron microscopy of a control kidney showed preservation of cellular architecture, which contrasted with the observed cytoplasmic vacuolation of proximal tubular cells after perfusion with diatrizoate. This study confirms a direct effect of WSCM on the function of the IPRK. In this experimental model, diatrizoate reproduces the effects observed in vivo on GFR and renal perfusion.
Phantoms for evaluating the performance characteristics of bone densitometers
Authors: Royle G. J. , Speller R.D.
Published: July 2009

Osteoporosis is characterized by a gradual loss of osseous tissue within the framework of the bone, which lowers bone strength and so increases the risk of fracture. A variety of techniques exist for identifying early bone loss, such as single- or dual-photon absorptiometry (SPA, DP A), quantitative computed tomography (QCT), etc. (Speller et al, 1989). Those commonly employed concentrate on the rate of decrease in bone density or bone mineral content within a particular site. The skeletal sites that become most susceptible to fracture are those with high trabecular content, namely the distal radius, the femoral neck and the lumbar vertebrae. For diagnosis of osteoporosis serial density measurements need to be performed at regular intervals over a period of many months. The frequency at which measurements are performed must be determined by the precision of the machine as compared with the decrease in bone density over that period of time. The reported rates of bone loss for normal post-menopausal women are 1.2% per year for trabecular bone (vertebral QCT measurements; Cann et al, 1985) and 0.9% per year for cortical bone (SPA measurements of mid-radius; Mazess, 1982). Therefore, the precision of the method must be sufficient to allow the machine to detect the small changes in bone density that occur in the space of a few months. Thus, knowledge of the precision and accuracy of the machine is essential. All systems when installed are supplied with a calibration phantom.
Dural venous sinus thrombosis following myelography: demonstration by magnetic resonance imaging
Authors: Hartley R. W. J. , Jackson A. , Cooke R. S.
Published: July 2009

Headache is a common complication of myelography, occurring in approximately 30% of cases (Wilkinson & Sellar, 1991). The headaches may be severe and are frequently postural in nature. We present a case in which a severe post-myelographic headache progressed over a period of six weeks. The development of fundal haemorrhages with visual impairment prompted investigation by magnetic resonance imaging (MRI) which demonstrated thrombosis of the right transverse sinus. Anticoagulant therapy led to prompt relief of symptoms and improvement of visual acuity.

A 51-year-old man presented to another hospital with three days of severe low back pain and right-sided sciatica. Initial examination demonstrated reduced straight leg raising on the right but no other abnormality. Initial treatment with seven days bed rest resulted in no improvement and a lumbar myelogram was performed using iohexol (Omnipaque, 240mg/ml, Nycomed Ltd). Myelography demonstrated no evidence of significant abnormality and the patient's symptoms resolved spontaneously.
Book reviews
Authors: Whitehouse G. H.
Published: July 2009

This monograph encompasses the extensive experience and expertise of its author, who has pioneered the technique of magnetic resonance imaging (MRI) of the breast using gadolinium enhancement, and has been eagerly awaited by those who practise in this field. Dr Heywang-Kobrunner's technique uses a 3D gradient echo fast imaging sequence with a slice thickness of no more than 5 mm.
Book reviews
Authors: Raphael M. J.
Published: July 2009

This book is essentially the proceedings of a conference held in June 1989 on the progress in quantitative coronary arteriography and related techniques. It consists of a pot pourri of topics. Part I, some 132 pages long, considers the problems and solutions in directly measuring coronary arteries and their stenoses. Part 4 considers the methods of measuring coronary flow reserve and their potential pitfalls.
Uptake of technetium-99m methylene diphosphonate by a pulmonary hamartoma/mesenchymoma
Authors: Burke W , Rubens M B
Published: July 2009

Pulmonary hamartomas (or mesenchymomas) are benign developmental abnormalities of the lung, and are usually discovered as an incidental finding on a chest radiograph. Some exhibit characteristic “popcorn” calcification that may be recognized on plain chest radiography or standard tomography (Bateson et al, 1960), but computed tomography (CT) has been shown to be more sensitive in detecting calcification (Siegelman et al, 1980).

Bone scanning using technetium-99m methylene diphosphonate (99Tcm MDP), a bone-seeking radiopharmaceutical, provides information that reflects skeletal metabolic activity. We report a case of pulmonary hamartoma in which a carcinoma developed in the contralateral lung. In the course of investigating the patient a bone scan was performed and radioisotope uptake by the hamartoma was observed. As far as we are aware this has not been described previously in a pulmonary hamartoma.
Book reviews
Authors: Reidy J
Published: July 2009

This substantial text book has been produced by a cardiac radiologist with help from about 50 contributors, mainly radiologists from the United States. The layout is unusual, being “uniquely based on the physiologic and anatomic conclusions ascertained from the chest film which is still the most accurate and inexpensive non-invasive examination”.
Book reviews
Authors: Testa H J
Published: July 2009

This volume is part of a series of books entitled “A Clinician'sGuide to Nuclear Medicine” written under the auspices of the British Nuclear Medicine Society. It is aimed at clinicians interested in nuclear medicine as part of their own specialty. It consists of an introduction (Chapter one) and six other chapters.
The dose-fractionation sensitivity of the kidney; assessment of viable tubule cross-sections at 19 months after X irradiation
Authors: Jen Y-M , Hendry J H
Published: July 2009

The formation of viable tubule cross-sections was assessed in histological sections of murine kidneys at 19 months after fractionated bilateral X-ray doses with 12 h intervals between fractions. The data were analysed using the linear-quadratic model which provides values of α and β characterizing the slope of the dose-response curve, and the ratio of α and β indicative of the sparing effect of dose fractionation. The tubule data were characterized by α = 0.057 ± 0.009 Gy-1, β = 0.011 ± 0.001 Gy-2, α/β = 5.0 ± 0.9 Gy. Also, the number of cells (per focus region of the nephron) calculated as being capable of producing a viable focus was 2.5 ± 0.5, which was confirmed using a separate two-dose approach (2.1 ± 0.3). Together with other data, of the order of 1000 regenerative cells per nephron (104 total cells) can be deduced. The values of the fractionation sensitivity parameters are similar to values measured previously for cells taken from irradiated kidneys up to a year after irradiation and forming colonies in primary culture, and also similar to values assessed using various functional measures of kidney injury.
Optimization of X-ray spectra for mammography
Authors: Whall M A
Published: July 2009

The introduction of a dual-track anode X-ray unit for mammography (IGE Senographe DMR) prompts some consideration of the optimization of X-ray spectra used for this examination on existing units. A considerable number of the X-ray units used for screening and symptomatic mammography in the UK and elsewhere employ a molybdenum anode tube with molybdenum filtration, usually 0.03 mm thick, using a tube potential of around 30 kVp.
Hair raising artifacts in magnetic resonance imaging
Authors: Williamson V C
Published: July 2009

A 44-year-old shot blaster from Camel Lairds ship yard was referred to the neurology outpatients clinic with a history of episodes of diplopia and ptosis. These had been occurring over the past 7 years and all had resolved fully. In addition, he had had an episode of weakness in the left leg when aged 8 years old. This had lasted for a few weeks before resolving.

In view of the above history, demyelinating disease was considered, and a magnetic resonance (MR) scan requested. Images were obtained on a General Electric Signa 1.5 Tesla scanner using spin-echo sequences. A T  1weighted (TR = 600 ms, TE = 30 ms) sagittal series, and an axial proton density and T2 weighted sequence (TR = 2000 ms, with dual echoes at 20 ms and 80 ms) were performed.
Comparison of various film densitometers
Authors: Burch A , Goodman D A , Hill S J , Law J , Robinson A , Underwood A C
Published: July 2009

Quality control techniques are increasingly being applied in general radiography and particularly in mammography. A densitometer is an important basic tool for quality control measurements, and may be used for checking film processor performance (in conjunction with a sensitometer) and for measuring optical densities at test points on a radiograph of an image quality phantom (BIR, 1988; IPSM, 1989). Incorrect calibration or drift of such an instrument could give a misleading impression of the performance of the imaging system when performing comparisons with colleagues. The purpose of the present work was to establish whether differences between instruments are likely to be a significant source of error.

In a quality control programme, all measuring equipment should be calibrated at a frequency that may be advised by the manufacturer; in the absence of such advice, this would typically be on an annual basis. The densitometers discussed here were not calibrated especially for the study, except where this was a part of the routine method of use.

A test strip was produced, having a range of optical densities, for circulation to the authors. The strip was produced by exposing a Kodak MinRE mammography film to a nine-step optical sensitometer (“QA Sensi-Densitometer” Model SDM, MIC Medical Ltd). This resulted in nine areas of the film, each roughly 1 cm square, with various densities in the range approximately 0.2–3.3.
Book reviews
Authors: Mayles P
Published: July 2009

This book is intended as an introduction to medical physics for radiotherapists. It begins with an explanation of the concept of kinetic and potential energy and works up from there. The text is very clear and well written and diagrams are good. For someone starting from a limited background in physics this would be an excellent book to enable them to get a feel for what radiotherapy physics is all about.
Book reviews
Authors: Faulkner K
Published: July 2009

This book is the proceedings of an American College of Medical Physics conference on “Current Regulatory Issues in Medical Physics” which was held in April 1992. The text is based on the various oral presentations made at the meeting, supplemented by copies of the regulations. It is interesting to note that in some instances the rationale for the regulations is described. The editors should be congratulated on producing this book so soon after the meeting. It represents a comprehensive and authoritive text on this subject.
Observer variation in ultrasound assessment of the thyroid gland
Authors: Jarløv A E , Nygård B , Hegedüs L , Karstrup S , Hansen J M
Published: July 2009

In order to determine observer variation in the assessment of the thyroid gland by ultrasonography, two specialists (one endocrinologist and one radiologist) independently evaluated 76 thyroid glands, and assessed the sonogram as homogeneous, inhomogeneous, containing a solitary solid lesion or a solitary cyst in each of 152 thyroid lobes. The observed agreement between the two observers ranged from 0.80 to 0.91. By the use of the kappa coefficient the observed agreement was adjusted for change agreement. Kappa can vary from − 1 (total disagreement) to + 1 (total agreement) and kappa values between 0.55 and 0.60 were found. Among 152 lobes a solitary solid lesion, i.e. a nodule, was found in 22 lobes by the two observers; however, they only agreed on a classification in 10 lobes (45%). Clinicians should be aware of the moderate agreement between observers in thyroid ultrasonography.
The management of stroke during intraarterial thrombolysis
Authors: Nyamekye I , Beard J , Gaines P
Published: July 2009

Intraarterial thrombolytic therapy is being increasingly used in the treatment of acute limb ischaemia. When strokes occur during thrombolytic therapy treatment is usually stopped because of the suspicion of cerebral haemorrhage. If the stroke is not haemorrhagic then stopping the treatment jeopardizes the ischaemic limb. If the stroke is proven to be non-haemorrhagic on computed tomography (CT) then the thrombolytic therapy should be recommenced. We present three case histories of patients who suffered a stroke during thrombolytic therapy over a 30-month period, in whom CT confirmed non-haemorrhagic stroke and we suggest that managing the ischaemic limb with anticoagulant and thrombolytic therapy can be safe in the early period following the stroke. We also discuss the probable aetiology of the strokes and whether cardiac echocardiography should be performed in these patients.
Assessment of X-ray field alignment in mammography
Authors: Brennan A G , Johnson C H
Published: July 2009

It was with some interest that we read the above paper by Kotre et al (1993). We have formerly addressed this problem and have devised a measurement technique with an identical measurement accuracy (± 0.5 mm) which has been presented at two major conferences (Brennan & Johnson, 1992, 1993). Our measurement method was also presented to fellow physicists at a UK Mammography Physics Group Meeting on 7 November 1991 in Manchester.
A reference frame designed to use external numeric references during simulation for tumours located in the head
Authors: Niël C
Published: July 2009

The interest in three-dimensional radiation therapy planning and conformal beam therapy is increasing rapidly as the equipment necessary for these techniques becomes commercially available. Compared with classical two-dimensionally planned two- and three-field irradiation this new treatment mode can achieve higher tumour doses with simultaneous reduction of radiation dose to surrounding normal tissue by the use of five or more external, multi-leaf collimated radiation beams. Beam positioning, however, can diverge from the treatment plan as assessed by computer planning since (often complex) anatomical structures are used as a reference to position the irradiation beams at the time of simulation. We therefore developed a reference frame to enable the use of external numeric references in the craniocaudal, anteroposterior and laterolateral direction as a guide for beam positioning on the simulator. In this study we evaluate the accuracy of such a frame and the reproducibility of its use.

Four lucite (polymethylmethacrylate) arcs were constructed with holes drilled every centimetre. All arcs were identical in form, size and location of the holes. Two identical frames were constructed by connecting two arcs (Figure 1a) by the use of one lucite rod at the top (Figure 1b) and two lucite plates at the base (Figure 1c), the latter having two metal rods perpendicular to the plates to ensure reproducible positioning of the frame by corresponding holes in the base plate of the immobilization set-up (Figure 1d).
Isolated atraumatic third nerve palsy: clinical features and imaging techniques
Authors: Renowden S A , Harris K M , Hourihan M D
Published: July 2009

We have reviewed 34 consecutive patients imaged for an isolated third nerve palsy over a 2-year period. With pupil sparing the third nerve palsy was most often due to ischaemic microvascular disease. The commonest cause of a third nerve palsy with pupillary involvement was a posterior communicating artery aneurysm. Clinical features such as speed of onset, pain and completeness of palsy were not reliable in the diagnosis of either the nature or the location of the cause. Pupillary involvement was however often associated with a compressive lesion. Imaging along the whole course of the nerve is recommended for adequate evaluation.
Child abuse—necklace calcification—a sign of strangulation
Authors: Carty H
Published: July 2009

Strangulation has been postulated as one cause of cerebral hypoxia in child abuse. This report describes the finding of necklace calcification in an infant with rib fractures and a metaphyseal fracture and an admission of a shaking injury. The calcification is likely to represent fat necrosis as the result of strangulation.
Book reviews
Authors: Moskovic E
Published: July 2009

This genuinely pocket-sized handbook contains 500 pages of highly concentrated information about the anatomy, radiology and pathology of the face, skull base and neck. It is organized principally into three closely defined anatomical regions: suprahyoid neck, infra-hyoid neck, and head and neck above the hard palate.
Angioplasty gives good results in critical lower limb ischaemia. A 5-year follow-up in patients with known ankle pressure and diabetic status having femoropopliteal dilatations
Authors: Jeans W D , Cole S E A , Horrocks M , Baird R N
Published: July 2009

137 consecutive patients with known ankle pressures and diabetic status had attempted femoro-popliteal dilatation for lower limb ischaemia in an English provincial teaching hospital. All except one were followed until failure or death to assess survival and amputation rates. Non-diabetic patients with critical limb ischaemia had a 5 year survival rate of 62.2% (SE 17.1) compared to 50.5% (SE 7.0) for claudicants, with no significant difference on logrank testing. Diabetics had a relative risk of amputation of 11.2 compared to non-diabetics. Patients with pre-treatment ankle pressures of 50 mm or less had a relative risk of amputation of 2.6 compared to those with higher resting pressures. It is concluded that angioplasty should be the treatment of first choice in critical lower limb ischaemia whenever it is technically possible. Including patients with rest pain in the critical ischaemia group does not significantly affect cumulative patency rates.
Craniospinal axis irradiation: an improved electron technique for irradiation of the spinal axis
Authors: Li Chun , Muller-Runkel R , Vijayakumar S , Myrianthopoulos L C , Kuchnir F T
Published: July 2009

In this work we review the dosimetric features of craniospinal axis irradiation in the areas of matching cranial and spinal fields, with reference to the normal structures within the spinal field. The implications of the use of photon or electron modalities for the spinal port were evaluated. A novel method of matching the cranial photon and the spinal electron fields involving a computer-aided junction design is presented. The technique involves moving the photon beam in three steps to degrade its penumbra to match that of the electron field. Thermoluminescent dosimetry in a Rando phantom and computed tomography-based dose–volume histogram study for an illustrative paediatric case were used to compare the dose to normal structures within the spinal field. Our results show that the use of electrons for the spinal field leads to better sparing of deep seated normal structures. In the case of bone marrow, the use of a customized bolus for the spinal field results in an improved dose distribution, making electrons potentially superior to photons for radiobiological reasons.
Computed tomography and magnetic resonance in the diagnosis of intraventricular cerebral masses
Authors: McConachie N S , Worthington B S , Cornford E J , Balsitis M , Kerslake R W , Jaspan T
Published: July 2009

We describe a series of 60 cases of patients with masses arising within the cerebral ventricles. The site and relative frequency is noted for each histological type. The differential diagnosis depends on patient age and sex, site, morphology and number of masses, presence and type of hydrocephalus and the characteristics of the mass on computed tomography (CT) and magnetic resonance (MR) images. A review of the literature has been performed and this information collated with our own experience to give detailed descriptions of the typical features of each intraventricular mass. Attention is drawn to intraventricular neurocytoma, a recently described tumour that may be mistaken histologically for intraventricular oligodendroglioma or ependymoma. A comparison is made of the value of CT and MR in the diagnosis of intraventricular masses.
Book reviews
Authors: Gedroyc W
Published: July 2009

This is a very welcome and timely book from the well knownGerman expert in this field, Dr Kaiser. MR mammography hasbeen nurtured and developed to its current state by Dr Kaiser and several other workers in Germany and it is a tribute to their efforts that MR mammography is becoming a widely accepted new technique in the investigation of breast carcinoma and indeed many MRI machine manufacturers are now producing dedicated breast coils for this application.
Computed tomographic scanning of L3/4 in suspected disc prolapse: is it necessary?
Authors: de Vos Meiring P , Gandhi M , Nakielny R A
Published: July 2009

Computed tomography (CT) scanning is an accepted first line investigation for suspected lumbar prolapsed intervertebral disc disease (PID). However, it does involve ionizing radiation and any possible reduction in the dose is desirable. A questionnaire was sent to a random selection of 60 CT centres in the UK to confirm that a routine scan of the three lower lumbar levels is current practice in a majority of centres, regardless of symptomatic presentation. All orthopaedic CT referrals over 2 years for suspected lumbar disc disease in Sheffield were studied retrospectively. Of 486 cases, 99 (20%) were shown to have disc disease, of which 16 (3.3%) had disease at the L3/4 level. Of these 16 cases, 11 were suspected clinically. Analysis of the long-term outcome of the five unsuspected cases showed that in none did the CT findings make any significant contribution to this outcome. These results have altered our practice. Two-level scanning is now performed routinely and three-level scanning is only performed when specified clinical or radiological indications are present.
Scintigraphic evaluation of sialadenitis
Authors: Hughes P M , Carson K , Hill J , Hastings D
Published: July 2009

Salivary gland scintigraphy using 99Tcm sodium pertechnetate and a 20-min dynamic data acquisition with a sialogogue at 10 min was employed as the primary imaging modality in sialadenitis in 32 patients. Paired asymptomatic glands within the study group were used to establish control values for a number of computer-derived functional parameters. The shape of the activity-time curve was described as: H = hyperactive, N = normal, M = median, S = sloped, F = flat, 0 = obstructed. Of seven patients who had ductal stones on plain films, two passed stones prior to sialography and had normal curves, whole the remaining five patients had Type O curves. Parametric evidence of gland dysfunction was identified in an additional seven symptomatic glands, six being hyperactive; histology identified an acute inflammatory infiltrate in the only excised gland in this group. Glandular hypofunction was identified in one case, in which histology revealed extensive fibrosis and glandular atrophy. Type M and S curves were found in 28 glands, 75% of which were asymptomatic. Only one gland was indicated as hypoactive by calculated parameters, and this showed a Type S curve. Scintigraphy and plain films represent the least invasive and, we feel, the most suitable primary method of investigating sialadenitis. Conventional contrast sialography may be reserved for cases with no identifiable stone but an obstructed curve. The use of functional parameters and curve morphology to determine gland dysfunction other than obstruction is non-specific, probably insensitive and is unlikely to alter clinical management. We propose an algorithm for the investigation of sialadenitis.
67Ga scintigraphy in HIV antibody positive patients; a review of its clinical usefulness
Authors: wassie E , Buscombe J R , Miller R F , Ell P J
Published: July 2009

We reviewed the results of 67Ga scintigraphy in HIV antibody positive patients in order to determine how the result affected management. Case records of 37 HIV antibody positive patients undergoing 67Ga scintigraphic studies over a 31 month period were examined. New and additional information was provided by 67Ga scintigraphy in 22 studies (53%). In 13 studies (32%) there was a positive effect on patient management. 67Ga scintigraphy was most useful in differentiating Pneumocystis carinii pneumonia from Kaposi's sarcoma in the chest and for the diagnosis of unsuspected lymphoma. Factors which reduced the effectiveness of 67Ga scintigraphy included empirical use of antibiotics in patients with suspected infection and the low specificity of the test.
Evaluation of a region growing algorithm for segmenting pelvic computed tomography images during radiotherapy planning
Authors: Neal A J , Sivewright G , Bentley R
Published: July 2009

A clinical evaluation of a computer segmentation algorithm was performed to determine whether the incorporation of such an algorithm into a radiotherapy treatment planning computer would increase the speed of segmentation and therefore increase user productivity. Six pelvic computed tomography (CT) data cubes were manually segmented akin to current radiotherapy practice on three occasions and the mean times for each data cube recorded to provide baseline measurements. The same images were then segmented using the new region growing algorithm, backed up by manual segmentation and contour editing tools where necessary, and the times compared with the baseline for each data cube. The results confirm that this algorithm can decrease segmentation times by a factor of 2.4 without compromising the quality of the final plan (p <0.0001). Most of this time gain is from a rapid segmentation of the pelvic bones and external contour rather than the soft tissues of the pelvis. We conclude that such algorithms will be of value for segmenting large pelvic CT data cubes for radiotherapy planning by making the procedure less labour intensive.
Comparison of spiral-acquisition computed tomography and conventional computed tomography in the assessment of pulmonary metastatic disease
Authors: Collie D A , Wright A R , Williams J R , Hashemi-Malayeri B , Stevenson A J M , Turnbull C M
Published: July 2009

In a prospective study, spiral-acquisition computed tomography (SACT) of the thorax was evaluated in 104 patients with extrathoracic malignancy and suspected pulmonary metastases, and was directly compared with conventional computed tomography (CCT) in 23 patients. The following parameters were assessed: lesion detectability; the effect on lesion detectability of reconstruction of scans at 5 mm and 10 mm slice increments; breathing artefact and slice misregistration. The radiation dose of the two techniques was measured using thermoluminescent dosimeters placed within an anthropomorphic chest phantom, and the visibility of simulated metastases inserted into the phantom was also compared using CCT, standard SACT and SACT with pitch greater than 1.0. Where metastases were present, SACT scans showed significantly better lesion detectability than CCT scans (p < 0.001). Image reconstruction of SACT data at 5 mm increments conferred no significant advantage in lesion detectability over 10 mm increment reconstructions. Compared with CCT,SACT scans showed reduced breathing artefact, and a complete absence of slice misregistration (p < 0.01). Phantom measurements of radiation dose and resolution were similar for both techniques. Increasing the pitch of the spiral in SACT caused only a small decrease in phantom resolution, but with the advantage of a reduction in the radiation dose. Spiral-acquisition CT is superior to conventional CT for the assessment of pulmonary metastatic disease.