bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of MR sequences in quantifying in vitro cartilage degeneration in osteoarthritis of the knee.
Authors: Uhl M , Allmann K H , Tauer U , Laubenberger J , Adler C P , Ihling C , Langer M
Published: June 2014

Magnetic resonance imaging of amputated human knees was performed to determine optimal sequences for depicting articular cartilage. 24 knees were examined with eight different sequences in a 1.0 T imager. Each cartilage lesion was graded from 1 to 4 (Outerbridge staging system). The results of each sequence were compared with the macroscopic findings and statistically tested against each other. The FLASH sequence (TR = 50 ms) with combination of flip angle of 40 degrees and echo time of 10 ms and the FISP sequence (TR = 40 ms) with combination of flip angle of 40 degrees and echo time of 11 ms were best for depicting cartilage structure and internal detail. There was no significant difference between fat-saturated three-dimensional FLASH (FS-3D-FLASH) and FS-3D-FISP (p = 0.05). These FS-3D sequences were significantly better than sequences without fat saturation (p = 0.05). There was no significant difference between magnetization transfer (MT) 3D-FLASH, MT-3D-FISP and 3D-FISP. All 3D sequences showed significantly (p = 0.05) better results than spin echo or fast spin echo sequences. The T1 weighted SE pulse sequence was significantly (p = 0.005) better than the T2 weighted TSE sequence. Fast T2 weighted spin echo was not suitable for early and accurate detection of cartilage lesions.
Selective delivery of 10B to soft tissue sarcoma using 10B-L-borophenylalanine for boron neutron capture therapy.
Authors: Pignol J P , Oudart H , Chauvel P , Sauerwein W , Gabel D , Prevot G
Published: June 2014

Boron neutron capture therapy (BNCT) may improve the locoregional control of radio/chemoresistant tumours like soft tissues sarcomas (STS). This technique uses the 10B(n,alpha)7Li nuclear reaction to destroy tumour cells, provided that a sufficient amount of 10B may be carried selectively into them. In order to evaluate the targeting potential of 10B-L-borophenylalanine (BPA) a 10B biodistribution study was carried out in 24 Wistar rats bearing Yoshida sarcoma. Six animals received increasing intraperitoneal doses of BPA (300, 600 and 1200 mg kg-1), while the remainder received a BPA dose of 600 mg kg-1 but with a sacrifice at six different time points: 1, 2, 4, 6, 9 and 12 h. The 10B concentrations in the tumours, normal tissues and blood were analysed with neutron capture radiography (NCR). The analysis shows that 36 micrograms g-1 (+/- 4 SD) of 10B may be incorporated into the tumour, with a ratio of 13 (+/- 4 SD) versus the muscle and a ratio of 15 (+/- 3 SD) versus the blood, 6 h after an intraperitoneal injection of 600 mg kg-1 of BPA. The BPA appears to be abundantly incorporated in the tumour, and the kidney proximal tubule area. These data suggest that BNCT using BPA may provide an improved therapeutic ratio for the treatment of STS.
Metastatic cardiac osteosarcoma--imaging features.
Authors: Atra A , Shankar A G , Padhani A R
Published: June 2014

There are several reports of osteosarcoma metastases to the heart. A rare case of a metastatic osteosarcoma to the endocardium of the left atrium in a 17 year old patient is described. The radiological features are discussed in detail.
Appearances of paranasal fungal sinusitis on computed tomography.
Authors: Dahniya M H , Makkar R , Grexa E , Cherian J , al-Marzouk N , Mattar M , Saghir E , Fathi al-Samman T
Published: June 2014

The primary invasive granulomatous form of fungal sinusitis, due to inhalation of aspergillus spores, is commonest in the Sudan and the Gulf states. This condition often presents clinically as a chronic, severe sinusitis which has not responded to antibiotics. On CT scanning, the major feature is a soft tissue mass, which is either homogeneous or has lower attenuation components. There may be erosion or expansion of the bony margins of the sinuses. Intraorbital and/or intracranial extension sometimes occur.
Observer variation in plain radiography of the lumbosacral spine.
Authors: Espeland A , Korsbrekke K , Albrektsen G , Larsen J L
Published: June 2014

In this study, interobserver and intraobserver variations in the interpretation of plain radiographs of the lumbosacral spine were evaluated. Three radiologists independently interpreted the radiographs from 200 consecutive outpatients, aged 13-93 years, mostly referred from general practitioners. Interobserver agreement was best for vertebral fractures, osteopenia, spondylolisthesis at L5-S1, lumbosacral junctional vertebra, reduced disc height at L4-S1 and osteophytes at L2-S1 (kappa 0.61-0.95), and poorest for spina bifida of S1, degenerative spondylolisthesis and facet joint arthrosis at T12-L4, sacroiliac joint arthrosis, narrow central spinal canal, film quality, and for decisions concerning evaluation of facet joints and spinal canal (kappa < 0.34). For several diagnoses, the number of abnormal findings differed significantly between observers (p < 0.05, McNemar's test), indicating different diagnostic thresholds. Intraobserver agreement in 36 reevaluated patients was fair to excellent for almost all variables (kappa > 0.46). Although some diagnoses related to low back pain were quite consistently evaluated, the substantial disagreement on many findings should alert clinicians and radiologists against overestimating the validity and usefulness of the examinations. To improve diagnostic consistency, it is important to reduce variation caused by different thresholds for abnormality.
The effect of radiographic contrast media on human vascular smooth muscle cells.
Authors: Wang Y X , Chan P , Morcos S K
Published: June 2014

The relation between intravascular radiographic contrast media (RCM) and myointimal hyperplasia after percutaneous transluminal angioplasty is not known. We have investigated the cytotoxic effects of RCM on human vascular smooth muscle cells (VSMCs) and their effect on the growth of these cells. The cytotoxic effects of RCM were studied using human VSMCs. The cells after being grown to confluency were exposed for 60 min to 250 mgI ml-1 of diatrizoate, ioxaglate, iopromide, iotrolan and saturated mannitol solutions. The control group was treated with only 15% fetal calf serum (FCS) containing medium. The viability of the cells was examined using the trypan blue exclusion test. The effect of RCM on growth was assessed by exposing the VSMCs after growth arrest, for either 15 or 60 min to 250 mgI ml-1 of diatrozoate, ioxaglate, iopromide, iotrolan and saturated mannitol solution. There was no significant change in the viability of the VSMCs after 60 min exposure to iopromide, iotrolan, saturated mannitol solution, and after 15 min exposure to diatrizoate or ioxaglate. After exposure to diatrizoate or ioxaglate for 60 min, 16.5 +/- 2.2% or 9.2 +/- 2.6% dead cells were found, respectively (p < 0.05 versus control). In the growth assay of VSMCs, diatrizoate, ioxaglate and saturated mannitol solutions reduced the growth rate (p < 0.05 versus control). No significant change was observed with iopromide and iotrolan. In conclusion, ionic RCM have cytotoxic and cytostatic effects on VSMCs while non-ionic media have no effects. There is no direct stimulatory effect of contrast media on the growth of VSMCs. The cytotoxic and cytostatic effects of contrast media seems to be both osmolality and chemotoxicity dependent. Low osmolar non-ionic RCM are not likely to contribute to the mechanisms responsible for myointimal hyperplasia after angioplasty.
Comparison of the precision of two vertebral morphometry programs for the lunar EXPERT-XL imaging densitometer.
Authors: Harvey S B , Hutchison K M , Rennie E C , Hukins D W , Reid D M
Published: June 2014

Comparative precision tests of the vertebral height measurement function of the Aberdeen Vertebral Morphometry System (AVMS) software and Lunar EXPERT-XL software were undertaken using four vertebrae from the same lateral spine dual energy X-ray absorptiometry (DXA) image of the same subject (male, 67 years). Two of the vertebrae were abnormal and two were normal. Three observers inexperienced in morphometry and one experienced observer took part in the study. Repeatability was obtained from 10 sequential measurements of the posterior, middle and anterior heights at the same sitting by the same observer. Intraobserver reproducibility compared the means of one set of measurements for all vertebrae with another taken 1 week later. Interobserver reproducibility compared the means of one set of measurements for all vertebrae from an experienced and an inexperienced observer, and from two inexperienced observers. The AVMS software had significantly higher (p < 0.05) repeatability (mean coefficient of variability, CV = 3.5%) than the Lunar software (mean CV = 5%), significantly higher (p < 0.01) intraobserver reproducibility (mean CV = 4.6%) than the Lunar software (mean CV = 8.5%), and significantly higher (p < 0.05) interobserver reproducibility (mean CV = 4.7%) than the Lunar software (mean CV = 7.5%). In conclusion, the new AVMS method possessed higher precision when measuring both abnormal and normal vertebrae and when used by both experienced and inexperienced observers.
MRI of a giant splenic artery aneurysm.
Authors: Kehagias D T , Tzalonikos M T , Moulopoulos L A , Gouliamos A D , Mourikis D A , Vlahos L J
Published: June 2014

Aneurysms of the splenic artery larger than 3 cm are very rare. We present the imaging features of a 12 cm, partially thrombosed splenic artery aneurysm. MRI was valuable in establishing the diagnosis.
A 10 year audit of antenatal ultrasound detection of renal disease.
Authors: Dillon E , Ryall A
Published: June 2014

During a 10 year period, a renal tract anomaly was suspected on antenatal ultrasound in 125 fetuses, an incidence of five per 1000 births. 107 live births resulted. Three of six babies with renal failure were stented antenatally. A chromosome anomaly was present in three fetuses (2.4%). No live birth resulted in 14 pregnancies associated with oligohydramnios and no visible fetal bladder. Of those with renal agenesis or bilateral cystic dysplasia, one had a chromosome defect and a further four had extrarenal anomalies. Nine fetuses demonstrated isolated parenchymal hyperechogenicity and trisomy occurred in two of four with bilateral change in enlarged kidneys. All 14 babies with unilateral renal cysts had normal renal function postnatally, but only three of the cystic kidneys showed function. Antenatally, typical multicystic change was seen in 10, and smaller unevenly distributed cysts in four kidneys. Contralateral parenchymal echogenicity and/or pelvicalyceal distension indicating dysplasia was identified in four fetuses. Of 78 fetuses with isolated pelvic with or without calyceal distension the outcome was completely normal in 59% with unilateral, and in 48% with bilateral changes. One baby with unilateral and three with bilateral changes required dialysis or renal transplantation. One of four babies with antenatal ureteric distension had renal failure. Only one of six fetuses with bladder distension is alive in renal failure after in utero stenting.
The use of TIPS to control bleeding caput medusae.
Authors: Fitzgerald J B , Chalmers N , Abbott G , Lee S H , Warnes T W , Youngs G R , Wardle T D
Published: June 2014

Two patients with cirrhosis and portal hypertension had persistent bleeding from caput medusae and ascites. Transjugular intrahepatic portosystemic shunt (TIPS) resulted in regression of the caput medusae and ascites in both cases.
Radiology of adjustable silicone gastric banding for morbid obesity.
Authors: Pretolesi F , Camerini G , Bonifacino E , Nardi F , Marinari G , Scopinaro N , Derchi L E
Published: June 2014

We reviewed the radiological findings in 45 morbidly obese patients (weight range 80-129 kg; mean 95.7 kg) after gastric restriction surgery with adjustable silicone gastric banding (ASBG) according to the Kuzmak technique. Radiographic studies of the stomach were performed before, and at 4 and 12 months after surgery; symptomatic patients underwent additional studies when needed. Patients were evaluated using both liquid barium and a solid opaque meal to assess post-operative gastric morphology as well as emptying time of the proximal gastric pouch. 27 patients had a normal clinical course. Variation of the calibre of the silicone band under radiographic guidance was required in 12 of these patients, based on dilatation of the proximal pouch, variation of the stomal calibre from operative values, or an emptying time longer than 30 min. All these problems disappeared after the adjustment manoeuvres. 18 patients had complications, of which five had stomal stenosis which could not be managed through simple deflation of the band; two had posterior bending and dilatation of the proximal pouch; four had gastritis and oesophagitis; six had infection of the inflatable reservoir; one had cranial displacement of the band, and two had migration of the band into the stomach. Removal of the gastric band was necessary in 11 cases, and removal of the reservoir alone had to be performed in three additional patients. Radiology plays an important role in evaluating complications after gastric restriction surgery. Knowing the variety of findings enables accurate treatment planning and follow-up of these patients.
Mediastinal venous anomalies: potential pitfalls in cancer diagnosis.
Authors: Padhani A R , Hale H L
Published: June 2014

Mediastinal venous anomalies encountered during CT assessments of cancer patients are often unsuspected and may be misinterpreted, particularly in the presence of intrathoracic disease. Errors in diagnosis result from a lack of intravenous contrast, concomitant mediastinal lymphadenopathy and primary intrathoracic tumour. The small calibre of vessels, previous mediastinal surgery and poor mediastinal planes are other confounding factors. An awareness of the anatomical features and optimal scanning technique are required to avoid misinterpretation.
Carotid artery stenosis in patients who have undergone radiation therapy for head and neck malignancy.
Authors: Dubec J J , Munk P L , Tsang V , Lee M J , Janzen D L , Buckley J , Seal M , Taylor D
Published: June 2014

Although it is established that small and medium sized arteries undergo extensive radiation damage, the effect on large vessels such as the carotid arteries is less well understood. We sought to determine if an increased severity of carotid artery stenosis is present in patients who have undergone radiotherapy for head and neck tumours. 45 patients aged 43-90 years (average 67) with head and neck malignancies treated with radiotherapy underwent colour Doppler ultrasonographic scanning of the carotid arteries. These patients were compared with a population of asymptomatic historical controls. 60% of patients demonstrated stenosis ranging from 21 to 86%. 38% of patients demonstrated a stenosis greater than or equal to 50%. Carotid artery stenosis appears to be increased in patients who have previously undergone treatment with radiotherapy to the head and neck regions compared with controls (p < 0.001). These findings suggest that radiation has an adverse effect on large vessels. Colour Doppler follow-up may be indicated for patients receiving head and neck radiation therapy.
The derivation of tissue-maximum ratio from percentage depth dose requires peak scatter factor to be considered a function of source-to-surface distance.
Authors: Bedford J L , Hansen V N , Webb S
Published: June 2014

A formula for the calculation of tissue-maximum ratio (TMR) from percentage depth dose (PDD) and peak scatter factor (PSF) is derived from first principles using a simple geometric model for the case when the field size for PDD and PSF is defined at the surface. The derivation is carried out in two ways: (a) taking field size for PDD and PSF as defined at the depth of maximum dose and then applying a conversion factor, and (b) by a direct derivation. The first of these methods yields a formula which agrees with BJR Supplement 25, but the latter yields a result which differs from it. Numerically, this difference is insignificant, but it has implications for the theoretical basis of the conversion formulae. The difference arises due to the translation of field size from one depth to another when calculating PSF: two different values of source-to-surface distance (SSD) yield two apparently different PSFs for the same size of field at the depth of maximum dose. Disagreements of this type are prevalent throughout the standard conversion formulae given in BJR Supplement 25 when field size for PDD and PSF is defined at the surface rather than at the depth of dose maximum. These disagreements are illustrated here using the conversion of PDD from one SSD to another as an example. The difficulty is overcome by considering PSF to be a function of SSD as well as field size.
Striking regression of radiation-induced fibrosis by a combination of pentoxifylline and tocopherol.
Authors: Delanian S
Published: June 2014

Radiation-induced fibrosis (RIF) is a terminal sequela to irradiation that does not regress spontaneously. A preliminary study of a combination of pentoxifylline (PTX) and tocopherol (vit-E) has shown clinical activity with 50% superficial RIF regression at 6 months in half of the patients studied. The present report is of a 67-year-old woman presenting with bulky cervicothoracic RIF who, 10 years previously, had received radiochemotherapy for a small cell thyroid carcinoma to a dose of 50 Gy, with severe acute side-effects. She had palpable cervicosternal fibrosis measuring 10 x 8 cm, with local inflammatory signs and functional consequences (cough, restricted cervical movement, dyspnoea and bronchitis) with a SOMA scale for grading the long-term side effects of radiation therapy of 19/14. CT showed deep RIF extending from the vocal cords to the carina, with laryngotracheal compression but without cancer recurrence. PTX (800 mg d-1) and vit-E (1000 U d-1), orally administered daily for 18 months, were well tolerated. The patient exhibited clinical regression and functional improvement. The linear dimensions and SOMA scale were, respectively, 8 x 6 cm and 11 at 6 months; 4 x 4 cm and 7 at 12 months; and complete response with no measurable RIF and 1 at 18 months. This is the first time that the combination of PTX and vit-E has had a significant antifibrotic effect by completely reversing deep RIF as shown by CT scan normalization.
An in vitro study comparing two different film-screen combinations in the detection of impacted fish bones.
Authors: Abdullah B J , Kaur H , Ng K H
Published: June 2014

Dried fish bones from eight species of Malaysian fish were placed in an animal cadaver at four sites (tonsil, valleculae, larynx and oesophagus) and radiographed using a double and a single film-screen combination. The use of the single film-screen combination resulted in visibility of all fish bones placed in the larynx, two of which were not visible on the double film-screen combination. There was a 50% increase of the visibility of the fish bones in the oesophagus using the single film-screen combination. The difference in dose and cost between the two different film-screen combinations was not significant.
Optimizing optical density of a Kodak mammography film-screen combination with standard-cycle processing.
Authors: McParland B J , Boyd M M , al Yousef K
Published: June 2014

The optimization of optical density in film-screen mammography is crucial in attaining good image quality. While a target range for film optical density of 1.4-1.8 has been recommended for centres participating in the National Health Service Breast Screening Programme (NHSBSP), past investigations have shown that combinations of mammography film and screen and processor conditions can have various optimum densities, some of which are outside this recommended range. The optimum optical density of the film/screen/processor conditions combination used at our institution (the Kodak MIN-RM/MIN-R combination designed for standard-cycle processing) was evaluated using a breast detail phantom study. It was found that the optimum optical density was 1.25 OD. We recommend that an individual institution determines the optimum optical density for the film-screen combination it uses and the processing conditions specific to it.
CT measurement of main pulmonary artery diameter.
Authors: Edwards P D , Bull R K , Coulden R
Published: June 2014

The aim of this study was to determine the upper limit of the normal main pulmonary artery diameter using a modern CT system. This was measured at the level of the pulmonary artery bifurcation in 100 normal subjects using unenhanced contiguous 10 mm CT slices viewed at fixed mediastinal window settings (400/20). These normal subjects were then compared with similar unenhanced 10 mm images from 12 patients with proven pulmonary arterial hypertension (mean pulmonary artery pressure > 20 mmHg). The main pulmonary artery diameter in normal subjects was 2.72 cm (SD = 0.3). Main pulmonary artery diameter in patients with pulmonary arterial hypertension was significantly greater (p < 0.01) at 3.47 cm (SD = 0.33). A pulmonary artery diameter of 3.32 cm (main pulmonary artery diameter + 2 SD) had a 58% sensitivity and 95% specificity for the presence of pulmonary arterial hypertension. It is concluded that, using unenhanced axial 10 mm CT sections, the upper limit of normal main pulmonary artery diameter is 3.32 cm. Pulmonary arterial hypertension should be considered in patients with values above this level.
Prevalence of deep vein thrombosis in suspected and proven pulmonary embolism: a meta-analysis.
Authors: van Rossum A B , van Houwelingen H C , Kieft G J , Pattynama P M
Published: June 2014

The purpose of this study was to determine the prevalence of lower extremity deep venous thrombosis (DVT) in patients with suspected and proven pulmonary embolism (PE). A meta-analysis was performed, based on literature from January 1983 to June 1997. Papers obtained from a computer-aided literature search were divided into studies with pulmonary angiography or ventilation-perfusion (V/Q) scintigraphy as the reference study. Our own observational data of the prevalence of DVT in 149 patients suspected of PE were also reported. The estimated prevalence of DVT in patients with proven and suspected PE was calculated. In the 149 patients studied, the prevalence of DVT was 12% with suspected PE and 32% (95% confidence interval 20-46%) in patients with proven PE. The individual studies showed a considerable heterogeneity, the prevalence of DVT in proven PE ranged from 10 to 93%. The pooled estimate of the prevalence of DVT in patients suspected of PE, over all studies, was 18% (95% confidence interval 15-20%). The DVT prevalence in proven PE was 36% (95% confidence interval 22-52%) in the angiography-based studies, and 45% (95% confidence interval 33-58%) in the V/Q scintigraphy-based studies. In conclusion, the current meta-analysis shows that the prevalence of DVT in suspected PE is approximately 18%, and in proven PE 36-45%.
Treatable lesions demonstrated on vertebral angiography for posterior circulation ischaemic events.
Authors: Crawley F , Clifton A , Brown M M
Published: June 2014

Angiography after a posterior circulation ischaemic event is often not considered because of the perception that it will not alter patient management. We identified 53 patients investigated with vertebral angiography over a 5 year period. This was significantly abnormal in 32 patients (60%). Five (9%) had vertebral artery dissections, nine (17%) had unilateral vertebral artery occlusion, two had a basilar artery disease. 16 (30%) had vertebral artery stenosis. 12 stenoses were considered suitable for percutaneous transluminal angioplasty (23%). 11 patients were anticoagulated (21%). There was no significant correlation between clinical features, site of infarct or the presence of carotid stenosis that would have allowed the prediction of the findings in the posterior circulation. Our results indicate that using vertebral angiography to investigate posterior circulation ischaemia will identify a significant number of potentially treatable lesions.
Variation of patient dose in head CT.
Authors: Smith A , Shah G A , Kron T
Published: June 2014

CT dose varies with both equipment related and operator dependent factors. Thermoluminescence dosimetry (TLD) was employed in two phantoms to investigate the variation in absorbed dose for head CT scans, using a cylindrical head CT dose phantom. Dose profiles were plotted and the computed tomography dose index (CTDI) calculated for a single 10 mm thick slice on 14 CT scanners. An anthropomorphic head phantom was also scanned from the base-of-skull to the vertex using 10/10 mm slices. The absorbed dose measured at the centre of the scan series is reported (Dmid). The mean CTDIw for the 14 scanners was 60.0 mGy, while the mean Dmid was 45.8 mGy. Dmid better represents the absorbed dose in human tissues. The CTDIw and Dmid normalized to mAs varied by up to a factor of 2.2 for the different scanners. Equipment related factors contribute to such variations. However, variations due to operator dependent factors such as the choice of exposure factors, scanning protocol and positioning technique must also be considered. When such factors are taken into account the absorbed dose received by the patient can vary considerably, by as much as 16.2 for lens dose. Increased awareness of the factors influencing CT dose and the standardization of scanning protocols is recommended.
Biliary imaging by spiral CT cholangiography--a retrospective analysis.
Authors: Sajjad Z , Oxtoby J , West D , Deakin M
Published: June 2014

CT cholangiography employs spiral CT scanning after the administration of biliary contrast medium to generate three-dimensional images of the biliary tract. A retrospective review of 61 patients who had undergone CT cholangiography was performed to determine the technical efficacy and the clinical utility of the technique. The results of CT cholangiography were analysed retrospectively to determine technical success rate of the imaging procedure and to correlate imaging diagnosis with results of other diagnostic procedures and with clinical follow-up. 60 of the 61 examinations produced technically satisfactory images. 21 of these examinations showed bile duct abnormalities. (12 stones, 6 duct dilatation to papillary level, 2 post-operative strictures and 1 case of sclerosing cholangitis). The remaining 39 cases showed no bile duct abnormality. In 59 of the 60 cases, subsequent investigations and follow-up supported the CT cholangiographic diagnosis. CT cholangiography is a robust technique for imaging of the biliary tract and is a valuable addition to the battery of non-invasive biliary investigations.
Patient doses from barium meal and barium enema examinations and potential for reduction through proper set-up of equipment.
Authors: Yakoumakis E , Tsalafoutas I A , Sandilos P , Koulentianos H , Kasfiki A , Vlahos L , Proukakis C
Published: June 2014

Patient doses for barium meal and barium enema examinations, performed at two Greek hospitals, were measured using a dose-area product meter. The results were analysed to obtain the contributions of fluoroscopy and radiography to the dose as well as a number of other dose related parameters for each examination. The doses observed are within the range of values reported by other authors and comply with the dose reference levels (DRLs), proposed from relevant surveys in the UK and The Netherlands. However, comparison between the two hospitals revealed significant differences in the contributions to dose from the various parts of the examinations. To determine the reasons for these differences, measurements of dose related parameters were made using a Plexiglas phantom and standard clinical X-ray machine settings. Factors contributing to increased dose delivery were determined and recommendations have been made concerning ways in which doses might be reduced in each hospital, without degradation of the diagnostic quality of these examinations.
The X-ray and electron benchmarking of the Monte Carlo codes MCNP-4A and 4B on different computers.
Authors: Edwards C R , Mountford P J
Published: June 2014

MCNP (Monte Carlo N-Particle) is a Monte Carlo transport code which has been of widespread use in modelling the dosimetry of ionizing radiations. The most recent version (4B) features improved electron transport compared with the previous version 4A. The processing time required by a number of computing systems to carry out X-ray and electron transport calculations using both versions of the code was compared. Version 4A was installed onto a Dec Alpha Server 8200, a personal computer (Pentium 90 MHz), and a Sun Sparc20, 10, 4 and 1+. MCNP-4B was also installed onto the Sun Sparc20. The benchmark tests consisted of determining the transmission of 2 MeV X-rays and 30 MeV electrons through lead. It was found that the Dec Alpha Server 8200 was the fastest computing platform, and the Sun Sparc1+ was the slowest for both tests. The difference in computational speed between different platforms was not matched by the corresponding differences in price. The time required by version 4B to complete the X-ray and electron benchmark tests was found to be 1.4 and 2.3 times greater than version 4A, respectively, without any difference in the results of the calculation for each type of radiation. This suggests that in cases where computing time is important, it may be preferable to use version 4A instead of 4B.
The 4 year outcome following the demonstration of bilateral renal pelvic dilatation on pre-natal renal ultrasound.
Authors: Broadley P , McHugo J , Morgan I , Whittle M J , Kilby M D
Published: June 2014

There is little in the literature regarding long-term prognosis in cases of fetal pyelectasis and calyceal dilatation. The aim of this study was to correlate antenatal ultrasound findings with outcome in a large group of children, most of whom had routine antenatal mid-trimester scans. 75 babies with bilateral pyelectasis and calyceal dilatation in the pre-natal period and complete radiological and clinical data were identified over a 3 year period. Pre-natal ultrasound was correlated with results of post-natal investigation and the frequency of post-natal surgery was established. Follow-up was documented to discharge or to at least 4 years of age. Prognosis was related to the degree of pelvic dilatation, but neonatal morbidity was much more likely to be associated with pre-natal calyceal dilatation and/or hydroureter. 68% (51 of 75) of babies had insignificant abnormalities on post-natal investigation, defined as either transient fetal pyelectasis and calyceal dilatation, extrarenal pelves, or transient neonatal pyelectasis and calyceal dilatation. Five babies died in the neonatal period, all classified as either moderate or severe disease. Of the surviving 70 cases (93.3%), 27% had renal anomalies that required treatment by prophylactic antibiotics or surgery. The remaining babies were conservatively managed and followed as outpatients. One child required transplantation and a further two had a severe degree of chronic renal failure by the age of 4 years. These data will be of value in prospective counselling.
A model simulator for radiotherapy treatment planning and checking.
Authors: Seaby A W , Thomas M , Craven C
Published: June 2014

For a linear accelerator the direction and orientation of a beam is specified uniquely by a set of gantry, turntable and collimator angles. Sometimes, particularly for 3D planning, it is very difficult for the planner or plan checker to visualize the set-up of the treatment machine from the angles specified for each beam. This note describes a simple line-of-sight model that can be used for planning and checking the radiotherapy geometry prior to simulator verification.
Pre-surgical localization of ectopic parathyroid glands using three-dimensional CT imaging, 99Tcm sestamibi, and 99Tcm tetrofosmin imaging.
Authors: Ishibashi M , Uchida M , Nishida H , Hiromatsu Y , Kohno K , Okuda S , Hayabuchi N
Published: June 2014

We describe two patients with ectopic parathyroid glands evaluated with 99Tcm sestamibi, 99Tcm tetrofosmin, and three-dimensional computed tomography (3D-CT). Radionuclide images of the neck were acquired at 10 min, and at 2-3 h after radiopharmaceutical injection, and showed intense uptake in the ectopic parathyroid tissue. These patients also underwent contrast enhanced CT imaging with 3D reconstructions which were evaluated for ability to visualize critical anatomical structures, e.g. blood vessels and parathyroid glands. Based on 3D-CT images, surgical planning was altered in one of the two patients studied. In conclusion, reconstructed 3D-CT images provided useful anatomical localization of ectopic parathyroid glands identified on 99Tcm sestamibi and 99Tcm tetrofosmin imaging. This anatomical information aided surgical planning of gland resection.
Differential diagnosis of gynaecological "stained glass" tumours on MRI.
Authors: Tanaka Y O , Nishida M , Kurosaki Y , Itai Y , Tsunoda H , Kubo T
Published: June 2014

Although multilocular cystic gynaecological masses in which the loculi show variable signal intensity on both T1 and T2 weighted images have been considered to be mucinous cystadenoma or adenocarcinoma, other gynaecological tumours can demonstrate this "stained glass" appearance. These include mature cystic teratoma, fibrothecoma, endometrioma, Brenner's tumour of the ovary and degenerated leiomyoma of the uterus, all of which may mimic mucinous tumours of the ovaries.
The reliability of bone age determination in central European children using the Greulich and Pyle method.
Authors: Groell R , Lindbichler F , Riepl T , Gherra L , Roposch A , Fotter R
Published: June 2014

This study assessed the reliability of bone age determination in normal central European children using the Greulich and Pyle method and determined the effects of readers' experience on the measured bone ages. Plain hand radiographs of 47 children (aged 2 months to 18.8 years) with normal growth were analysed by four radiologists (two experienced paediatric radiologists and two radiology residents). The readers were blinded to the age of the children. The images were re-read by the same readers 2 months later. The mean intraobserver and interobserver variations were lower for experienced readers than for radiology residents. However, these differences were not statistically significant at the 5% level. The difference between the chronological age and the measured bone age was -1.5 +/- 7.6 months (p = 0.20) for the experienced readers and 2.7 +/- 10.3 months (p = 0.09) for the radiology residents. The differences between the measured bone age and chronological age were statistically significant (p = 0.04) for only one of the two radiology residents. Although the measurements by all four readers underestimated the chronological age, the differences between chronological age and bone age were within the normal variations of skeletal maturation as reported by Greulich and Pyle. Our data suggest that the reliability of bone age measurements increases with experience and that the Greulich and Pyle method may be used for central European children.
Is there an improvement in performance when radiographs are re-reported at 24 hours?
Authors: Tudor G R , Finlay D B
Published: June 2014

This study was designed to assess the accuracy and intraobserver variability when plain radiographs are re-reported after 24 h, in order to determine if there was a change in observer performance. Five consultant radiologists reported 50 plain radiographs on patients in whom the diagnosis had been established. The radiographs were reviewed by each radiologist after an interval of 24 h. The same clinical information was available on both occasions. 32 of the radiographs showed an abnormality and 18 were normal. The accuracy of the report in relation to the established diagnosis was assessed, intraobserver agreement being calculated using kappa (kappa) statistics. The kappa-value for intraobserver agreement was in the range 0.33-0.88. Accuracy showed a range of 78-90% on the first viewing and 80-92% on the subsequent viewing. ROC curves were produced for each viewing for the group as a whole. The areas under the curves were 0.88 and 0.9 respectively. For the group, the accuracy increased on the second occasion, but this did not reach statistical significance.
The benefits of hospital-wide picture archiving and communication systems: a survey of clinical users of radiology services.
Authors: Bryan S , Weatherburn G C , Watkins J R , Buxton M J
Published: June 2014

This paper describes one element of a broad evaluation of a hospital-wide picture archiving and communication system (PACS): an assessment of the views of users of the radiology service, their major causes of dissatisfaction with the service, the incidence of image unavailability, and the consequences of images being unavailable. The principal research design was a "before and after" comparison at Hammersmith Hospital, as the hospital site introducing PACS. Several other hospitals were included in this survey, for comparison. Questionnaires were distributed several times before PACS was operational at Hammersmith, and on one occasion after. The overall response rate was 54%. The main pre-PACS radiology-related problem areas were: the non-availability of images, the non-availability of written reports when clinically required, and the time devoted by junior staff to image searching. PACS greatly reduced the perceived problem of image non-availability. But Hammersmith's problems with the availability of radiological reports still remained when PACS was operational. The time junior doctors spent in image-searching was dramatically reduced by the introduction of PACS.
The effect of a picture archiving and communication system (PACS) on patient radiation doses for examination of the lateral lumbar spine.
Authors: Weatherburn G C , Bryan S
Published: June 2014

This study was conducted to determine whether the doses for the radiographic examination of the lateral lumbar spine changed as a result of the introduction of a hospital-wide picture archiving and communication system (PACS). Doses were measured by thermoluminescent dosimeters (TLD) and dose-area product (DAP) meter readings for 100 patient examinations using a 300-speed conventional film/screen system and for 96 patient examinations when PACS was fully operational. Radiographic technique, exposure factors and patient characteristics were noted and effective doses were calculated, and a comparison was made of all variables. No significant differences between conventional and PACS working were found in surface entry and effective doses for single views of the lateral lumbar spine, but there was a 20% reduction in DAP readings with PACS. However, when summed doses for all images, including rejects, required to demonstrate the lateral lumbar spine for each patient were compared, PACS was found to be associated with significantly lower surface entry (TLD) dose, DAP reading and effective dose (28%, 36% and 16%, respectively) than conventional film. For single images of L1-5, when PACS was in use, there was a significant reduction in the DAP readings and increases in the area of the film/plate irradiated, the focus-to-skin distance and the focus-to-film distance. In addition, significantly fewer lumbosacral junction views were undertaken when PACS was in use. Since many confounding factors may have influenced the results over the period of dose measurement, regression models were used to determine the significance of PACS. These models showed that the use of PACS was not significant in causing any differences in the dose for single images as compared with when film was used, but was significant in the resulting total dose reductions for the examinations.
Interpretation of selected accident and emergency radiographic examinations by radiographers: a review of 11000 cases.
Authors: Robinson P J , Culpan G , Wiggins M
Published: June 2014

Two specially trained radiographers took part in the radiologists' rota for "cold" reporting skeletal radiographs of patients who attended the Accident and Emergency (A&E) Department at times when there was no "hot" reporting service operating, and who were not admitted for treatment or referred to fracture clinics for follow-up. These radiographs had initially been seen by A&E medical staff. At the end of an 18 month period during which the two radiographers reported on 11,322 skeletal examinations, a retrospective search was made to detect interpretive errors. The radiological history of all 11,322 patients was reviewed over a follow-up period of at least 3 months subsequent to the attendance reported by the radiographers. 48% of patients did not re-attend, 42% re-attended for unrelated examinations, and 10% re-attended for repeat examinations of the same anatomical area, or for different procedures (bone scintigraphy or CT) related to the original injury. The second (or subsequent) report was discrepant with that of the first attendance in only 29 cases out of 1103. Of these 29 patients, 13 had occult fractures which were undetectable at first attendance even in retrospect, six had new injuries accounting for the new findings, six had been the subject of false positive calls at an earlier visit, one had a fracture of the hamate missed at first attendance, and in three cases no consensus could be reached as to the cause of the discrepancy, owing to incomplete films or insufficient clinical data. Analysis of the patients' postcodes showed at least 89% were of local origin and only 1% were from outside Yorkshire, suggesting that the review should have identified the great majority of erroneous reports. It is concluded that appropriately trained and supervised radiographers can successfully undertake diagnostic reporting of selected skeletal examinations on A&E patients.
A preliminary study for clinical pharmacokinetics of oral fluorine anticancer medicines using the commercial MRI system 19F-MRS.
Authors: Ikehira H , Girard F , Obata T , Ito H , Yoshitomi H , Miyazaki M , Nakajima N , Kamei H , Kanazawa Y , Takano H , Ito H , Tanada S , Sasaki Y
Published: June 2014

These preliminary studies of dynamic natural abundance 19F-magnetic resonance spectroscopy (19F-MRS) on 5-FU based medicines were performed in the human liver using commercial 1.5 T MRI equipment. A single tuned, custom-made circular shape surface coil with a diameter of 15 cm operating at 60 MHz was used for the 19F-MRS study. Localized proton shimming with a whole body coil was performed with adequate volume to include the observing area of the surface coil, and the line width of the water signal was less than 40 Hz. Very different spectroscopic appearance patterns of 5-FU were observed. We examined whether the pharmacokinetics in the liver of orally administered 1-hexylcarbamoyl-5-fluorouracil (HCFU) differ from those of orally administered 5'-deoxy-5-fluorouridine (5'-DFUR). This preliminary study suggested the 19F-MRS technique could be a useful method of evaluating in vivo the metabolism of 5-FU based medicines.
Comparison of MRI with CT for the radiotherapy planning of prostate cancer: a feasibility study.
Authors: Khoo V S , Padhani A R , Tanner S F , Finnigan D J , Leach M O , Dearnaley D P
Published: June 2014

This feasibility study was performed to evaluate the suitability of MRI in defining appropriate pelvic radiotherapy treatment volumes, and to compare MRI sequences with CT for prostate cancer radiotherapy. Five patients with localized prostate cancer, imaged with four MRI sequences (spin echo (SE) T1, turbo SE (TSE) T2, high resolution TSE (HR) T2, and FLASH 3D (F3D)), compared with their corresponding CT planning scans. Segmentation ability of the following pelvic structures: prostatic apex (PA), prostate, rectum, bladder and seminal vesicles (SV), were evaluated by three independent observers. They used a five point grading scale based on the anatomical definition of the organ boundary, tissue contrast and multiplanar display. Results were averaged for the group and for each sequence. There was no significant interobserver variation in the assessed scores (p > 0.1). The average scores (+/- 1 SD) for all pelvic structures assessed by each imaging sequence were CT 1.3 +/- 0.6; SE T1 2.4 +/- 0.9; TSE T2 2.4 +/- 0.7; HR T2 2.2 +/- 0.7 and F3D 3.4 +/- 0.6. Compared with CT, the average MR score for each assessed pelvic structure was higher with a trend for all transaxial MR sequences to provide improved segmentation of the PA and rectum. The F3D sequence scored highest as it provided multiplanar views and avoided the problem of partial volume averaging. MRI, compared with CT, appears to provide improved definition of pelvic treatment volumes but further work is required to confirm this and to address the issues of MRI associated distortion and dosimetry before MRI can be used routinely for pelvic radiotherapy planning.
Plexiform neurofibroma of the small bowel infiltrated with metastatic adenocarcinoma.
Authors: Leslie A , Virjee J P , Moorghen M
Published: June 2014

Neurofibromatosis Type 1 (NF1) is not classically associated with gastrointestinal manifestations although these patients are at increased risk of several GI complications. We describe the ultrasound, CT and barium findings in a patient with NF1 who had a huge benign plexiform neurofibroma of the ileum that was infiltrated with metastatic adenocarcinoma.
MRI of thoracic vascular lesions with emphasis on two-dimensional time-of-flight MR angiography.
Authors: Ko S F , Wan Y L , Ng S H , Lee T Y , Cheng Y F , Wong H F , Hsieh M J
Published: June 2014

MRI is a valuable method for evaluating thoracic vascular lesions by virtue of its non-invasiveness and multiplanar capability. In addition, ionizing radiation and iodinated contrast medium are not required. Electrocardiographically gated T1 weighted spin echo MRI remains the principal technique for demonstrating the anatomy and morphology of thoracic vascular diseases. Cine MRI allows dynamic evaluation of vascular flow, whereas MR angiography is particularly useful in the two-dimensional (2D) or three-dimensional (3D) display of vascular anatomy. This pictorial review illustrates the use of 2D time-of-flight MR angiography in the assessment of various thoracic vascular conditions including aortic arch and great vessel anomalies, heterotaxic syndromes, aortic dissection, aortic or arch vessel aneurysms, pulmonary embolism, pulmonary sequestration, axillofemoral bypass and tumour/vessel relationships.
Transient splenomegaly in acute pancreatitis.
Authors: Tsushima Y , Tamura T , Tomioka K , Okada C , Kusano S , Endo K
Published: June 2014

Serial changes in splenic volume of 25 patients (18 men and seven women; 53.4 +/- 20.8 years old, range 25-83) with acute pancreatitis who underwent CT examinations were retrospectively studied. Abdominal CT was performed within 3 days after the onset and there was at least one follow-up CT examination after this time. The percentage changes of splenic volume in the first (4-30 days) and second (31-100 days) follow-up CT were calculated. Splenic volume increased in the first follow-up CT (mean +/- SD: 197.8 +/- 121.0 cm3) compared with the initial CT (124.8 +/- 70.0; p < 0.0001), and then decreased in the second follow-up CT (179.7 +/- 100.7; p < 0.002). The average splenic volume increased 65.5 +/- 88.7% (range -10.4-377.4%) between the initial and first follow-up CT examinations. Five of 25 cases (20%) in whom size of spleen increased more than twice had severe acute pancreatitis (p < 0.05), complicated pseudocyst requiring surgical drainage (p < 0.05), pleural effusion (p < 0.01), splenic vein thrombosis or compression (p < 0.05) and longer hospital stay (p < 0.02) compared with patients with a smaller increase in splenic volume. In conclusion, transient splenomegaly was commonly seen in acute pancreatitis, especially in severe or complicated cases. Congestive splenomegaly caused by obstruction or stenosis of the splenic vein and non-specified acute splenitis were suspected of contributing to the transient splenomegaly.