bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of bone mineral density and quantitative ultrasound of the calcaneus: site-matched correlation and discrimination of axial BMD status.
Authors: Langton C M , Langton D K
Published: June 2014

The performance of quantitative ultrasound (QUS) and dual energy X-ray absorptiometry (DXA) bone densitometry of the calcaneus have been compared, both in terms of site-matched correlation and their discriminatory ability to identify osteoporotic and osteoporotic or osteopenic subjects. 91 female subjects (aged 56.9 +/- 9.6 years, 31-84 years) who were routinely referred for axial BMD assessment of the lumbar spine and femoral neck by DXA (Lunar DPX-L), consented to have additional measurements of QUS (McCue CubaClinical Mk II) and DXA (Lunar PIXI) of their left calcaneus. The site-matched correlation between calcaneal BMD with QUS parameters were: (a) broadband ultrasound attenuation (BUA) alone, adj-R2 = 62.7%, p < 0.0001; (b) velocity (VOS) alone, adj-R2 = 48.4%, p < 0.0001; and (c) BUA and VOS combined, adj-R2 = 65.2%, p < 0.0001. The site-matched correlations are towards the higher end of data reported by other researchers, indicative of the exacting measurement protocol implemented here. 30 subjects were categorized as normal, 38 being osteopenic and 23 being osteoporotic. Optimum accuracies and odds ratios were obtained using logistic regression. The differences in accuracy between calcaneal BMD and calcaneal QUS parameters were statistically insignificant, with zero included within the confidence intervals, for the identification of both (a) osteoporotic and (b) osteoporotic or osteopenic subjects. The odds ratios for the discrimination of subject status achieved with calcaneal BMD were higher, although statistically insignificant, than achieved with the QUS parameters. Receiver operator characteristic (ROC) analysis for the identification of subjects into the categories (a) and (b) above was performed. Areas under the ROC curve (AUC) (95% confidence intervals) for the logit of the probability that a subject would be osteoporotic were: 0.814 (0.700, 0.928) for calcaneal BMD; 0.791 (0.673, 0.909) for BUA; 0.717 (0.588, 0.846) for VOS; and 0.793 (0.675, 0.911) for BUA and VOS combined. For the identification of osteoporotic or osteopenic subjects, the ROC areas were: 0.851 (0.774, 0.928) for calcaneal BMD; 0.773 (0.678, 0.868) for BUA; 0.783 (0.690, 0.877) for VOS; and 0.778 (0.685, 0.871) for BUA and VOS combined. Again, calcaneal BMD provided a higher, yet statistically insignificant, AUC than any QUS parameter. In conclusion, for the identification of subjects defined by World Health Organization criteria for axial BMD, the performance of BMD and QUS calcaneal parameters were statistically comparable. The choice of peripheral bone densitometry modality should therefore be made upon factors external to their discriminatory performance.
Application of draft European Commission reference levels to a regional CT dose survey.
Authors: Clarke J , Cranley K , Robinson J , Smith P H , Workman A
Published: June 2014

A survey of CT doses in Northern Ireland in the period between October 1995 and March 1997 was carried out. The survey included all but one of the 10 scanners in use at the time, and, additionally, two others that were replacement machines. The method used was to study standard protocols and calculate doses to the NRPB mathematical phantom, so that a direct comparison could be made with other surveys carried out in a similar fashion elsewhere. The survey addressed the patient radiation dose but not image quality or clinical outcomes. It is estimated that in Northern Ireland the contribution to collective dose to the population from CT is about 40% of that from all medical X-rays. The proposed European Commission reference quantities, weighted CT dose index and dose-length product were computed and their potential use evaluated. A full study of mean values of effective dose per examination revealed the average dose per examination was not significantly different from that found in the 1989 UK survey, although several procedures gave rise to doses that were high enough to be investigated with a view to justification or reduction. One of the scanners was found to give consistently high doses. It is likely that a revision of the mAs values used on this scanner will produce a significant reduction in patient doses without compromising image quality. When compared with the draft EC reference levels, fewer procedures were found to have excessively high dose values. The proposed EC reference levels would therefore be useful for continual monitoring of CT dose status, but do not appear to provide as comprehensive an assessment of patient exposure as that given by consideration of effective doses.
Dose response characteristics and basic dose distribution data for a polymerization-based dosemeter gel evaluated using MR.
Authors: Haraldsson P , Bäck S A , Magnusson P , Olsson L E
Published: June 2014

A safe and reproducible mixing procedure for the manufacture of a polymerization-based dosemeter gel evaluated using MRI (PoMRI) is presented. The dose response, obtained by irradiating gel-filled vials with absorbed doses in the interval 0-20 Gy and evaluated with respect to 1/T2, was found to be linear in the interval 0-8 Gy, with a sensitivity of 0.211 s-1Gy-1 (r2 = 0.998) at 1.5 T. Evaluation of the same set of vials with respect to 1/T1 gave a sensitivity of 0.018 s-1Gy-1 (r2 = 0.960). PoMRI and diode data were compared for standard photon and electron treatment beams. A deviation of less than 3% was found between the two methods for central depth dose curves as well as dose profiles (2 mm for electrons in the steep dose gradient regions). The importance of the method used for background correction for the reliability of the results was also evaluated. Barex (with a wall thickness of 1.5 mm) was investigated for use as phantom material and found to be favourable compared with glass. The results obtained in this study show that PoMRI has excellent potential as a 3D detector.
Intrathoracic extension of aggressive fibromatoses.
Authors: Shah J , Prasad S , Patkar D , Kothari S
Published: June 2014

Intrathoracic extension or primary thoracic origin of fibromatoses is distinctly uncommon. We describe the imaging features in three patients with this condition.
Issues of threshold selection when determining the fractal dimension in HRCT slices of lumbar vertebrae.
Authors: Haidekker M A , Andresen R , Evertsz C J , Banzer D , Peitgen H O
Published: June 2014

The box counting dimension is a frequently applied tool for the classification of trabecular bone structure. The algorithm requires a binarization of the gray value data, for example that acquired by high resolution CT (HRCT). We recently proposed a method to eliminate bone mineral density (BMD) by applying a linear normalization scheme. Further consideration has shown that full BMD independence has not been achieved, and the structural parameter proposed was therefore difficult to interpret. In this study we present an alternative approach to obtain a structural parameter that is independent of BMD. HRCT volume data was acquired on 21 lumbar vertebrae from five cadavers. In the segmented spongiosa, thresholding was based on different quantiles of the gray value histogram, yielding invariance over linear and non-linear transformations. Thresholding at high gray value levels (80% quantile) shows the highest level of significance when discriminating between osteoporotic and non-osteoporotic cases. As an addition to the measurement of BMD alone, the determination of structural properties allows an improvement of the assessment of the individual fracture risk.
Intraosseous venous drainage anomaly of the tibia treated with imaging-guided sclerotherapy.
Authors: Peh W C , Wong J W , Tso W K , Chien E P
Published: June 2014

A 23-year-old man presented with a pre-tibial soft tissue mass. Magnetic resonance images demonstrated the subcutaneous, intracortical and intramedullary components of an intraosseous venous drainage anomaly, which was confirmed by direct venography. Sclerotherapy using absolute alcohol was subsequently performed under imaging guidance with complete resolution of the subcutaneous component of the lesion.
Pancreatic serous cystadenoma associated with islet cell tumour.
Authors: Baek S Y , Kang B C , Choi H Y , Lee S W
Published: June 2014

We report the case of a 29-year-old female patient with a diffuse type of serous cystadenoma involving the entire pancreas except for part of the head, which was replaced by islet cell tumour. Ultrasound and CT showed multiple cysts in the entire pancreas and a solid mass with calcification in the head. MRI characterized the fluid content of the cysts and the extent of disease.
Characteristics of small lung cancers invisible on conventional chest radiography and detected by population based screening using spiral CT.
Authors: Sone S , Li F , Yang Z G , Takashima S , Maruyama Y , Hasegawa M , Wang J C , Kawakami S , Honda T
Published: June 2014

Conventional chest radiography (CXR) is a poor diagnostic tool for detecting lung cancers at a surgically curable stage. To determine the visibility of peripheral small lung cancers on CXR, we retrospectively examined the usefulness of CXR using a consecutive series of 44 cases detected on CT screening and later confirmed by histopathology. All cases had been detected by low dose CT during a population based screening trial for lung cancer. The control group consisted of 48 chest radiographs of normal subjects. Tumour diameters ranged from 6 mm to 45 mm, with 95% (42/44) < or = 20 mm, and 5% (2/44) > 20 mm. CXR failed to detect 77% (34/44) of all cancers, including 79% (33/42) < or = 20 mm and 50% (1/2) > 20 mm. Of the 42 lung cancers < or = 20 mm, 74% (31/42) were located in the well penetrated lung zones and 71% (22/31) of these were missed on CXR. 26% (11/42) were concealed by hilar vessels, mediastinum, heart or diaphragm, and all (11/11) of these were missed on CXR. 93% (39/42) of the lung cancers < or = 20 mm were adenocarcinomas and 79% (31/39) of these were missed on CXR. 7% (3/42) were epidermoid carcinomas or small cell carcinomas and 66% (2/3) of these were missed on CXR. The overall accuracy of interpretation on CXR for lung cancers was 61%, sensitivity was 23% and specificity 96%. Although there was an association between presence of lung cancer and positive reading of CXR (chi 2 test of association, p < 0.05), the percentage of positive readings was only 23%. Thus, CXR was poor at visualizing CT detectable lung cancers of < or = 20 mm diameter, which are usually of very low density, and cannot be relied upon for detection of surgically curable small lung cancer.
MRI of the claustrophobic patient: interventionally configured magnets.
Authors: Spouse E , Gedroyc W M
Published: June 2014

The aim of this study was to determine whether or not claustrophobic patients would tolerate a scan in an open configuration interventional magnetic resonance (iMR) imaging unit, when they had failed to complete a diagnostic scan in a conventional MRI system. 50 claustrophobic subjects were entered into the study. Their response to the iMR environment was compared with their previous experience in an MRI scanner by means of a two-stage questionnaire. Part 1 was completed before their iMR scan and Part 2 following their attempt at imaging in the iMR unit. 60% (n = 30) of the participants were female and 40% (n = 20) were male, age range 25-71 years (mean 49.5 years). 48% (n = 24) were lumbar spine studies and 28% (n = 14) were studies of the head. 24% (n = 12) underwent scanning of other anatomical regions. 94% (n = 47) of participants underwent successful MRI in the interventional magnet without extra sedation. 6% (n = 3) failed to complete a diagnostic scan in the iMR machine. The GE Signa 0.5 T SP magnet allows successful MRI in 94% of the claustrophobic population who have failed to complete a scan in a conventional diagnostic machine.
Factors affecting patient radiation exposure during routine coronary angiography in a tertiary referral centre.
Authors: Clark A L , Brennan A G , Robertson L J , McArthur J D
Published: June 2014

Cardiac catheterization is carried out by an increasing number of operators from district hospitals as well as tertiary referral centres. Procedures are not standardized and are at the discretion of individual operators. The purpose of this study was to describe the pattern of patient radiation dose and screening times associated with diagnostic cardiac catheterization, and explore determinants of radiation dose to patients and staff. Data were collected from 1337 diagnostic procedures carried out in two cardiac catheterization laboratories from January to June 1998. Screening time and radiation dose measured by dose-area product (DAP) meter were recorded. Status of the operator and type of investigation were determined. 22 operators had performed at least 15 left ventriculograms with coronary angiography (total 944 procedures). The average (+/- SD) was 40 (+/- 22) per operator. Screening times for individual operators varied from 2.0 (+/- 1.3) min to 5.0 (+/- 4.3) min with no relationship between time and number of cases. Consultants and visiting physicians had longer screening times and greater patient DAP readings. In comparison with 115 cases of coronary angiography alone, left ventriculography increased DAP reading from 14.24 (+/- 11.7) Gy cm2 to 20.26 (+/- 0.47) Gy cm2 (p < 0.0001). In 106 cases of coronary artery bypass graft angiography, an aortogram (n = 53) did not add significantly to radiation dose or screening time. A right heart catheter added approximately 5 min to screening time (9.13 (+/- 0.63) min with right heart (n = 83) vs 3.96 (+/- 0.12) min without right heart (n = 1234)), but did not affect radiation dose significantly. There is a wide range of screening times and radiation doses related to diagnostic cardiac catheterization. Visiting and consultant staff use greater radiation doses. Left ventriculography adds significantly to patients' radiation exposure. Aortography does not add significantly to radiation dose in cases of graft angiography.
Retroperitoneal fibrosis: typical and atypical manifestations.
Authors: Vivas I , Nicolás A I , Velázquez P , Elduayen B , Fernández-Villa T , Martínez-Cuesta A
Published: June 2014

Retroperitoneal fibrosis (RPF) is a well described clinical entity that is being diagnosed with increasing frequency. RPF is characterized by replacement of the normal tissue of the retroperitoneum with fibrosis and/or chronic inflammation. However, aetiology, clinical presentation and radiological appearance in many cases are protean. Up to 15% of patients have additional fibrotic processes outside the retroperitoneum. In the abdomen, RPF may spread contiguously to involve multiple structures in both the retroperitoneum and the peritoneal cavity or multiple non-contiguous sites may be involved. We retrospectively reviewed 30 patients (19 male, 11 female; age range 28-79 years) with biopsy proven RPF. Although we found RPF most commonly as an isolated fibrotic plaque in the lower lumbar region (18 patients), 12 patients (40%) presented with RPF in atypical locations (4 peripancreatic, 1 periduodenal, 7 pelvic). The RPF was non-malignant in 24 patients (21 idiopathic, 2 perianeurysmal, 1 ergot-derivative treatment) and malignant in six cases. We present a pictorial review of the varied appearances of RPF, concentrating on atypical sites. The radiological differential diagnosis and its appearance with various imaging modalities are discussed. Current concepts with respect to management, prognosis and treatment are summarized.
Imaging liver metastases: current limitations and future prospects.
Authors: Robinson P J
Published: June 2014

The diagnosis of liver metastasis relies on imaging. The sensitivity of ultrasound, CT and magnetic resonance techniques for detecting liver metastases can only be assessed in comparison with surgical inspection, intraoperative ultrasound and pathological examination, all methods that are of uncertain accuracy in detecting very small lesions. With current imaging technology, we should detect virtually all liver metastases 2 cm or larger in size, and most of those 1-2 cm in size. Even with optimum imaging, at present we detect only about one-half of metastatic nodules smaller than 1 cm in patients undergoing liver resection and pathological correlation. Improvements in the earlier detection of metastases will probably require a fundamentally different approach from that of conventional anatomical methods. Micrometastases produce alterations in blood flow that may be recognized by radionuclide or Doppler perfusion methods.
Distribution of cranial MRI abnormalities in patients with symptomatic and subclinical CADASIL.
Authors: Coulthard A , Blank S C , Bushby K , Kalaria R N , Burn D J
Published: June 2014

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a rare, inherited cause of early stroke and dementia, with a poor prognosis. This study was performed to clarify lesion appearance and pattern of lesion distribution in CADASIL. 20 members of a single family were tested for the CADASIL gene mutation and studied with cranial MRI. Scans were evaluated for lesion load and pattern of lesion distribution. 19 patients had cranial MRI, of whom 11 had normal MRI scans, were clinically unaffected and tested negative for the CADASIL gene mutation. The remaining eight patients had abnormal cranial MRI scans: seven patients were positive for the CADASIL gene mutation and one (untested) patient was severely clinically affected. Three of the patients who tested positive for the CADASIL gene mutation were clinically unaffected at the time of imaging. All eight patients with abnormal cranial MRI had subcortical white matter abnormalities, mostly in frontal and temporal lobes. Lesions involving the corpus callosum were present on sagittal T2 weighted images in four of five clinically affected and one of three clinically unaffected patients. Lesions involving the deep grey nuclei and the brain stem were common. On T1 weighted images, lesions were either poorly defined (confluent white matter hypointensity) or well defined (cystic infarcts or enlarged perivascular spaces). Atrophy was infrequent. Familiarity with the range of cranial MRI appearances may aid diagnosis of CADASIL. Recognition of cranial imaging features in asymptomatic CADASIL patients could prompt earlier diagnosis.
Radiation risk estimation in varicocele embolization.
Authors: Chalmers N , Hufton A P , Jackson R W , Conway B
Published: June 2014

Varicocele embolization is performed in healthy young men with normal life expectancy. Therefore, it is essential that the radiation risks associated with the procedure are minimized. The radiation risks associated with varicocele embolization have been estimated retrospectively from dose-area product records in a series of 41 cases and compared with a prospective series of 10 cases. Lithium fluoride dosemeters were used to measure gonad dose in the prospective series. Estimated lifetime fatal cancer risk was of the order of 0.1% in the retrospective series. A seven-fold reduction in median radiation dose was observed in the prospective series. The results indicate that with meticulous attention to technique, substantial reductions in radiation exposure can be achieved.
Acute mild hypothermia caused by a low dose of X-irradiation induces a protective effect against mid-lethal doses of X-rays, and a low level concentration of ozone may act as a radiomimetic.
Authors: Miyachi Y
Published: June 2014

Acute changes in core body temperature following exposure to a low dose of X-rays were assessed in unanaesthetized and unrestrained mice. Radiotelemetry techniques were used to monitor core body temperature continuously. Following exposure to a 20 cGy dose of X-rays, the mice displayed a rapid and significant reduction in core body temperature relative to the sham-treated (non-irradiated) control animals. The present studies, and those by others, showed that pre-exposure to X-rays at doses as low as 20 cGy may result in a reduced mortality rate following subsequent exposure to X-rays at mid-lethal dose levels. This indicates an increased tolerance to radiation. An additional experiment was conducted to examine whether the reduction in the mortality rate following exposure to mid-lethal doses of radiation could be found when mice were subjected to a stressor, ozone inhalation, which induced a suppression in body temperature. The results showed that following inhalation of ozone at a concentration of 0.5 ppm, 93% of the treated animals survived a mid-lethal dose of radiation, whereas 50% of the sham-control animals died within 30 days. These results suggest that low-dose-induced tolerance to radiation may be dependent on a brief exposure to ozone, and a reduction in core temperature may be necessary to obtain tolerance effects in response to a mid-lethal dose of radiation.
Tension pneumocephalus and pneumorachis secondary to subarachnoid pleural fistula.
Authors: Lin M B , Cheah F K , Ng S E , Yeo T T
Published: June 2014

A case of tension pneumocephalus and pneumorachis secondary to a subarachnoid pleural fistula after thoracic spinal surgery is described. This rare complication was diagnosed on CT. The imaging findings, significance and management of this unusual condition are discussed.
MR findings of ovarian tumours with cystic components.
Authors: Kinoshita T , Ishii K , Naganuma H , Higashiiwai H
Published: June 2014

This article depicts the MR findings of ovarian tumours with cystic components. MRI can predict the cyst contents and evaluate the potential for malignancy when an irregular solid portion or a papillary nodule is observed within the cystic tumour. Post-contrast T1 weighted MRI is helpful for the identification of solid areas that enhance. Fat suppression imaging is useful for differentiation between mature cystic teratoma and other pathology. Fat suppressed post-contrast T1 weighted MRI may demonstrate contrast enhancement, reflecting inflammatory or neoplastic processes in the pelvis.
Do bullae indicate a predisposition to recurrent pneumothorax?
Authors: Smit H J , Wienk M A , Schreurs A J , Schramel F M , Postmus P E
Published: June 2014

A relationship between idiopathic spontaneous pneumothorax (ISP) and visible parenchymal bullae and blebs has been reported. The causal relationship between blebs and bullae and ISP is questionable. Consequently, resection of the involved area is only indicated if it predisposes to recurrence of the pneumothorax. CT studies on 101 cases of ISP were analysed. The presence of bullae and their distribution was then related to the first and recurrent pneumothorax. CT demonstrated bullae in 56% of first ISP and in 64% of recurrent ISP, mostly among older patients. Only eight patients had bullae larger than 2 cm on the side of the pneumothorax. The location of the bullae was not a factor in predicting recurrent pneumothorax.
Reference dose levels for patients undergoing common diagnostic X-ray examinations in Irish hospitals.
Authors: Johnston D A , Brennan P C
Published: June 2014

Wide variations in patient dose for the same type of X-ray examination have been evident from various international dose surveys. Reference dose levels provide a framework to reduce this variability and aid in the optimization of radiation protection. The aim of this study was to establish, for the first time, a baseline for national reference dose levels in Ireland for four of the most common X-ray examinations: chest, abdomen, pelvis and lumbar spine. Measurements of entrance surface dose using thermoluminescent dosemeters (TLDs) for these four X-ray examinations were performed on 10 patients in each of 16 randomly selected hospitals. This represented 42% of Irish hospitals applicable to this study. Results have shown wide variation of mean hospital doses, from a factor of 3 for an anteroposterior lumbar spine to a factor of 23 for the chest X-ray. The difference between maximum and minimum individual patient dose values varied up to a factor of 75. Reasons for these dose variations were complex but, in general, low tube potential, high mAs and low filtration were associated with high-dose hospitals. This study also demonstrated lower reference dose levels of up to 40% when compared with those established by the UK and the Commission of the European Communities for four out of six projections. Only the chest X-ray exhibited a similar reference level to those established elsewhere. This emphasizes the importance of each country establishing its own reference dose levels that are appropriate to their own radiographic techniques and practices in order to optimize patient protection.
Direct measurement of air kerma rate in air from CDCS J-type caesium-137 therapy sources using a Farmer ionization chamber.
Authors: Poynter A J
Published: June 2014

A simple method for directly measuring the reference air kerma rate from J-type 137Cs sources using a Farmer 2571 chamber has been evaluated. The method is useful as an independent means of verifying manufacturers' test data.
Parametric mapping of scaled fitting error in dynamic susceptibility contrast enhanced MR perfusion imaging.
Authors: Li K L , Zhu X P , Jackson A
Published: June 2014

The purpose of this study was to examine the benefits of routine generation of a parametric image of scaled curve fitting errors in the analysis of dynamic susceptibility contrast enhanced MR perfusion imaging. We describe the scaled fitting error (SFE), which reflects the magnitude of potential errors in the estimation of perfusion parameters from dynamic susceptibility contrast enhanced studies. The SFE is the root-mean-square error between the observed values in the time course of change of effective transverse relaxation rate (delta R2* (t)) in tissue and the theoretical values derived by gamma variate curve fitting, scaled with a simple function related to the area under the fitted gamma variate curve. The SFE was tested using Monte Carlo simulation and by observations in normal volunteers and patients. This demonstrated that the SFE was linearly related to uncertainties in calculation of the values of relative cerebral blood volume (rCBV) and relative mean transit time (rMTT). High spatial resolution SFE maps were obtained in all volunteers and patients. In normal brain, SFE was consistently higher in white matter than in grey matter. In 54/85 patients with neurodegenerative or vascular brain disease, SFE maps showed focal areas with high values owing to poor signal to noise ratio in delta R2*(t). Increased SFE was also found in 11/54 brain tumours owing to loss of conformance of delta R2*(t) to the gamma variate function. SFE mapping is simple to implement and the computational overhead is negligible. It is concluded that parametric maps of SFE allow visual and quantitative comparison of fitting errors with the theoretical gamma variate model between anatomical regions and provide a quality control device to rapidly assess the reliability of the associated rCBV and rMTT estimations.
The incidence and significance of testicular microlithiasis in a subfertile population.
Authors: Thomas K , Wood S J , Thompson A J , Pilling D , Lewis-Jones D I
Published: June 2014

The objective of this study was to assess the frequency of testicular microlithiasis (TM) in infertile men who underwent testicular ultrasound and to determine any causative or associated factors. The case notes of 159 consecutive patients who were referred for testicular ultrasound in the investigation of male factor infertility were reviewed. Microcalcification was found in 10 cases (6.2%). This was unilateral in all cases and six patients had clinical evidence of a varicocele. Five cases had minimal calcification and five had marked TM. On patient had a past history of testicular maldescent and another of testicular torsion. Sperm function (as assessed by sperm count, motility and the sperm migration test) was variable within the 10 patients and there was no correlation with hormone profiles or testicular size. There was a statistical difference between a number of investigations in those patients with minimal degrees of calcification and those with TM (sperm migration test (SMT), namely sperm migration and sperm motility (p < 0.05, Mann-Whitney U test)). The results showed a higher than expected incidence of TM. Patients with marked TM seemed to have poorer sperm function than those with minimal calcification. There was a high incidence of co-existing pathology, for instance scrotal varicocele and cryptorchidism, although the numbers in this study were small and further studies need to be carried out to determine the exact nature and significance of this condition.
Correlation of patient skin doses in cardiac interventional radiology with dose-area product.
Authors: van de Putte S , Verhaegen F , Taeymans Y , Thierens H
Published: June 2014

The use of X-rays in cardiac interventional radiology has the potential to induce deterministic radiation effects on the patient's skin. Guidelines published by official organizations encourage the recording of information to evaluate this risk, and the use of reference values in terms of the dose-area product (DAP). Skin dose measurements were made with thermoluminescent dosemeters placed at eight different locations on the body. In addition, DAP was recorded in 100 patients for four types of interventional radiology procedures. Mean, median and third quartile for these results are presented. Maximum skin dose values found were 412 mGy, 725 mGy, 760 mGy and 1800 mGy for coronary catheterization, coronary catheterization with left ventricle investigation, and percutaneous transluminal angiography without and with stenting, respectively. Median DAPs for these same procedures were, respectively, 5682 cGy cm2, 10,632 cGy cm2, 10,880 cGy cm2 and 13,161 cGy cm2. The relationship between DAP and skin dose was investigated. We found a poor correlation of DAP with maximum skin dose (r = 0.77) and skin dose indicator (r = 0.78). Using conversion factors derived from Monte Carlo simulations, skin dose distributions were calculated based on the measured DAPs. Agreement between the calculated skin dose distribution, using DAP values averaged over a group of patients who underwent coronary catheterization and left ventricle investigation, and the measured skin dose averaged over the same group of patients was very good. However, there were large differences between the calculated skin doses using the individual DAP data per patient and measured skin doses for individual patients (r = 0.66). Hence, calculation of individual skin doses based on the specific DAP data per patient is not reliable and therefore measuring skin dose is preferable.
The radiological approach to precocious puberty.
Authors: Fahmy J L , Kaminsky C K , Kaufman F , Nelson M D , Parisi M T
Published: June 2014

Precocious puberty is caused by a heterogeneous group of disorders, which range from idiopathic to malignant tumours. The radiologist's role is to help: (1) differentiate precocious puberty from pubertal variants; (2) identify the underlying cause of precocity if present; and (3) assess for effectiveness of treatment. This pictorial review discusses the types of precocious puberty and their underlying aetiologies, differentiates precocious puberty from pubertal variants and illustrates the appropriate imaging evaluation for the patient diagnosed with precocious puberty.
Granularity of the carotid artery intima-medial layer: reproducibility of quantification by a computer-based program.
Authors: Ellis S M , Sidhu P S
Published: June 2014

Ultrasound of the carotid artery identifies the hypoechoic intima-medial layer (IML). Increased granularity of the IML has been associated with early atherosclerosis. The aim of the study was to assess the reproducibility and observer agreement of a computer-based program measure of IML granularity. Ten healthy adult volunteers (median age 32 years, range 18-34 years) were examined twice, 2 weeks apart, with a 7 MHz linear transducer using standardized imaging settings, by two observers. Images of both common carotid arteries were digitized and analysed on a customized computer program. The ratio (averaged over a 1 cm length of arterial wall) of the lowest pixel brightness in the IML to the maximum pixel brightness in the intima-medial interface was determined. Overall mean intima-medial reflectivity (IMR) indices for the two observers were 0.761 +/- 0.101 and 0.707 +/- 0.103, with single determination standard deviation values of 0.090 and 0.073, respectively. For interobserver calculations, the overall mean IMR index for both sessions was 0.734 +/- 0.107, with a single determination standard deviation of 0.067. Comparison with the intima-medial thickness (IMT) showed an inverse correlation (r = -0.72). This method of quantifying the reflectivity of the IML demonstrates good reproducibility in subjects with normal IMT measurements. The technique may be of value in identifying subjects at high risk of atherosclerosis but with IMT still within the normal range.
In vivo degradation of tungsten embolisation coils.
Authors: Butler T J , Jackson R W , Robson J Y , Owen R J , Delves H T , Sieniawska C E , Rose J D
Published: June 2014

It has been suggested that tungsten embolisation coils in intracranial aneurysms may dissolve in situ. These coils are also used, in much larger quantities, for the occlusion of larger vessels outside the cranium. This study was performed to investigate whether tungsten embolisation coils may become degraded in vivo and to examine whether this is radiographically evident on medium-term follow-up. 10 patients who had undergone aortic stent-graft repair of an abdominal aortic aneurysm (8 male and 2 female, mean age 69.7 years) and 10 age- and sex-matched controls were studied. The study group had also received an average of 64 cm of tungsten coil either to prevent or to treat an endoleak. Whole blood, serum and urine tungsten levels were assayed. Immediate post-operative and follow-up abdominal radiographs were reviewed by two consultant vascular radiologists to detect visible changes in the coils. Whole blood, serum and urine levels of tungsten were highly and significantly elevated (p < 0.001) in the study group compared with the controls. No radiographic changes in the coils were seen at an average of 16.7 months. In conclusion, tungsten embolisation coils dissolve in humans but radiographic changes are not apparent on medium-term follow-up. The clinical significance of these findings is uncertain but long-term follow-up is needed.
Improving radiographer highlighting of trauma films in the accident and emergency department with a short course of study--an evaluation.
Authors: McConnell J R , Webster A J
Published: June 2014

The case for radiographer abnormality highlighting in the Accident and Emergency (A&E) department is well documented. Following evaluative feedback, 280 questionnaires were sent nationally to A&E radiology departments (excluding Northern Ireland). The intent of the survey was to ascertain the viability of constructing a short course in trauma plain film pattern recognition in the axial and appendicular skeleton. Following a highly positive response a course was designed and operated on a workshop basis, being lead primarily by reporting radiographers. The course was evaluated for effectiveness using three identical assessments of 42 films, including 12 positive for trauma. A sample of 22 radiographers who attended the pilot course and subsequent courses throughout 1998/99 undertook the assessment. The assessments themselves were performed at the start and end of the course and 6-10 weeks after completion. Results appear to indicate that a significant improvement in the specificity (p = 0.002) and accuracy (p = 0.005) was achieved following the course. In the light of continuing professional development, the course appears to address the needs of the majority of clinical radiographers working in A&E.
False positive 131I whole body scans in thyroid cancer.
Authors: Mitchell G , Pratt B E , Vini L , McCready V R , Harmer C L
Published: June 2014

Well differentiated thyroid cancer is a rare disease in the UK. It is the only cancer which, having metastasized, remains curable by radioisotope therapy with 131I. The main indication for administering repeat doses of 131I is the appearance of abnormal uptake in a whole body scan following diagnostic or therapeutic 131I administration. False positive scans, showing the presence of 131I uptake in the absence of residual thyroid tissue or metastases can occur, although they are uncommon. Unless recognized as a false positive, 131I uptake may result in diagnostic error and lead to administration of an unnecessary therapy dose. We describe a series of nine patients in whom the scans showed false positive uptake of 131I, including cases where the cause of the uptake is still uncertain. We demonstrate the common sites of false positive uptake, discuss the underlying mechanisms and suggest a systematic approach to the interpretation of whole body scans in order to prevent unnecessary treatment with 131I.
The curved needle technique for accessing the L5/S1 disc space.
Authors: Kumar N , Agorastides I D
Published: June 2014

Bending the guide needle has been suggested as an alternative technique that may improve the success rate for accessing the L5/S1 level on discography. We performed a prospective randomized study to compare this technique with the use of a conventional straight needle. There was a significantly lower failure rate using the curved needle (p < 0.05). The incidence of nerve root impingement was also lower.
Pitfalls of breast MRI.
Authors: Coulthard A , Potterton A J
Published: June 2014

This article reviews some of the common pitfalls associated with breast MRI. Pitfalls can be broadly considered as "technical" (relating to patient factors or machine factors, which can influence image interpretation) or "non-technical" (relating to misinterpretation of imaging findings in the absence of technical problems). Awareness of potential pitfalls is important if MRI is to maximize its potential in breast imaging.
Effects of Lipochromin and Levosinum in the modulation of radiation-induced injury to pig skin.
Authors: Rezvani M , Uzlenkova N , Whitehouse E , Frenkel L , Wilkinson J H , Ross G , Morris G M , Hopewell J W , Pilipenko N
Published: June 2014

Pig skin was used as a model to study the effectiveness of two topically applied creams, Lipochromin and Levosinum, in modifying the development of both early and late radiation damage to pig skin. Irradiated skin sites that received daily topical application of Levosinum or Lipochromin after exposure were compared with sites on the contralateral flank of the same animal that received irradiation only. Irradiation was with graded doses of 90Sr/90Y beta-rays. Incidence of moist desquamation (acute) and ischaemic dermal necrosis (late) were used as end-points. The latency period for the development of moist desquamation and its healing time was also assessed. The latency period for the development of moist desquamation in this model ranged from 4.00-6.75 weeks. There was no significant difference between the cream treatment and control sites. Application of Levosinum shortened the healing time of moist desquamation at each dose level by 5-10 days. In three out of four dose levels used, this shortening of the healing time was statistically significant (p < 0.03). Treatment with these topical applications also reduced the incidence of late dermal necrosis and increased the ED50 values for the incidence of dermal necrosis. This increase in ED50 values was equivalent to a dose modification factor of 1.11-1.13.
A comparison of bolus chasing and static digital subtraction arteriography in peripheral vascular disease.
Authors: Ashleigh R J , Hufton A P , Razzaq R , MacDiarmaid-Gordon L
Published: June 2014

The purpose of this study was to compare the techniques of bolus chasing angiography (BCA) and digital subtraction angiography (DSA). 75 patients with symptomatic atherosclerotic peripheral vascular disease were randomly assigned to have their lower limbs examined by BCA or DSA. Dose-area product (DAP), time of examination and dose of contrast medium were measured. Staff doses were measured with personal electronic dosemeters. Image quality was assessed from the laser printed images. DSA produced better images of vessels below the inguinal ligament, particularly the crural vessels (1/76 vs 17/74 non-diagnostic examinations, p < 0.00001) but at a higher DAP (median 53.8 Gy cm2 vs 18.9 Gy cm2, p < 0.01). Contrast medium dose was higher with BCA (29.8 gI2 vs 25.3 gI2, p < 0.01). Staff doses per unit patient dose were 2.3-3.3 times higher with BCA than DSA. Because of the poor long-term prognosis of patients with peripheral vascular disease, the improved image quality obtained by DSA justifies the increased radiation dose.
Radiation doses to patients undergoing scoliosis radiography.
Authors: Chamberlain C C , Huda W , Hojnowski L S , Perkins A , Scaramuzzino A
Published: June 2014

In this study we computed the radiation doses associated with scoliosis radiography and investigated how these radiation doses are influenced by the weight of the patient. We recorded the radiographic technique factors of 61 consecutive patients (46 females and 15 males) undergoing scoliosis radiography. A wedge-shaped aluminium filter attenuated the X-ray beam in the "chest region" relative to the "abdomen region". X-ray tube air kerma output factors (microGy mAs-1) and half value layers (HVLs) were determined experimentally for the "chest region" and "abdomen region". The energy imparted to each patient was computed from the air kerma area product, X-ray beam HVL and measured patient thickness. Values of patient effective dose were obtained using effective dose-to-energy conversion factors for specified radiographic projections, taking into account each patient's weight. The median patient age was 17 years, and the median patient weight was 53 kg. Entrance skin air kerma values in the "chest region" were approximately a factor of four lower than those in the "abdomen region". The air kerma values increased by a factor of two when the patient weight increased from 30 kg to 70 kg. Approximately 80% of the total energy imparted to a patient undergoing a scoliosis examination was in the "abdomen region", with the remaining 20% imparted to the "chest region". Energy imparted increased with patient weight, and was approximately 3 mJ for a 30 kg patient and approximately 8 mJ for a 70 kg adult patient. Effective doses showed little correlation with patient weight, with an average-sized patient (50 kg) receiving an effective dose of approximately 140 microSv. Patients undergoing scoliosis radiography receive effective doses that are low in comparison with other types of radiographic examination.
Gadolinium-DTPA as X-ray contrast medium in clinical studies.
Authors: Albrecht T , Dawson P
Published: June 2014

The aim of this study was to investigate the contrast effects of gadolinium (Gd) in patients undergoing digital subtraction angiography (DSA), intravenous urography (IVU) and CT. 15 patients attending for coeliac axis DSA (n = 5), abdominal CT (n = 5) and IVU (n = 5) were injected with 0.3 mmol kg-1 Gd-DTPA, the maximum approved dose. For DSA and IVU, images were categorized as being of diagnostic or non-diagnostic quality. For CT, enhancement was measured in Hounsfield Units (HU). On CT, enhancement with Gd was reproducible in all cases; average peak aortic enhancement was 75 HU but duration was short. On IVU, four of five studies yielded positive pyelograms but all nephrograms were relatively poor. On DSA, all five patients had diagnostic arteriograms and four of five indirect portograms were of diagnostic quality. In all 15 cases, enhancement was weaker than that achieved with routine dosage of iodinated agents. In conclusion, Gd chelates may be clinically useful in X-ray studies under certain circumstances on patients with contraindications to iodinated agents. Higher doses than currently approved would be potentially useful.
Rapidly growing small peripheral lung cancers detected by screening CT: correlation between radiological appearance and pathological features.
Authors: Wang J C , Sone S , Feng L , Yang Z G , Takashima S , Maruyama Y , Hasegawa M , Kawakami S , Honda T , Yamanda T
Published: June 2014

12 peripheral small lung cancers (< 20 mm) of rapid growth (volume doubling time < 150 days), detected by repeated low dose CT screening, were evaluated to examine their CT features and to correlate such features with histopathological findings. Each patient's CT images, including follow-up and thin section CT images, were studied retrospectively to determine tumour growth rate and CT morphological features. Nine of the tumours exhibited a solid tumour growth pattern: seven of these showed a well defined, homogeneous, soft tissue density with spicular or lobulated margin. These seven tumours included small cell lung cancer (n = 3), moderately differentiated adenocarcinoma (n = 2), poorly differentiated adenocarcinoma (n = 1) and squamous cell carcinoma (n = 1). The other two tumours, a moderately differentiated adenocarcinoma and a well differentiated adenocarcinoma, appeared as irregular, soft tissue density nodules with poorly defined margins. The latter exhibited an air bronchogram pattern and a small cavity. The remaining three tumours exhibited a lepidic tumour growth pattern. They showed ground glass opacity or ground glass opacity with a higher density central zone on CT images and were well differentiated adenocarcinomas. In conclusion, most peripheral small lung cancers of rapid growth were adenocarcinomas. They also included small cell lung cancer and squamous cell carcinoma. The majority showed solid tumour growth pattern and lacked an air bronchogram and/or small air spaces in the nodule. Some well differentiated adenocarcinomas with lepidic tumour growth pattern also showed rapid growth.
CT diagnosis of acute appendicitis in a femoral hernia.
Authors: Zissin R , Brautbar O , Shapiro-Feinberg M
Published: June 2014

We present the first case, to our knowledge, of a patient with a CT diagnosis of acute appendicitis strangulated in a femoral hernia, a known but very rare entity. CT features of acute appendicitis within the hernia established the correct diagnosis. The pathological findings confirmed the diagnosis of this rare location of appendicitis.