bluuebunny/crossref_metadata_2025 huggingface dataset:
Radionuclide bone imaging for detection of mandibular invasion by squamous cell carcinoma.
Authors: Lewis-Jones H G , Rogers S N , Beirne J C , Brown J S , Woolgar J A
Published: June 2014

The assessment of mandibular invasion is an important part of the pre-operative staging of oropharyngeal squamous cell carcinoma. When bone is surgically resected, histology often shows no direct bone invasion, yet such resections are associated with post-operative complication and morbidity. This prospective study of a large group of patients aims to lay down criteria for bone invasion using radionuclide bone imaging and orthopantomography, and to test their effectiveness when compared with histological analysis. 77 patients with proven squamous cell carcinoma of the oral cavity were investigated pre-operatively by radionuclide bone imaging and orthopantomography. All had bone resected as part of complete resection of the tumour. One patient had systemic bone metastases and was, therefore, excluded. In the remaining 76 patients, there were four false positive assessments for bone invasion radiologically and no false negatives. There were 48 true positive results and 24 true negatives, giving a sensitivity of 100% and specificity of 86%. It is concluded that correct application of the outlined criteria for bone invasion demonstrated that radionuclide bone imaging and orthopantomography are a sensitive test for bone invasion, with an acceptable level of specificity.
Dosimetric properties of the Theraview fluoroscopic electronic portal imaging device.
Authors: Glendinning A G , Bonnett D E
Published: June 2014

Electronic portal imaging devices (EPIDs) can be used for non-imaging applications in radiotherapy such as patient dosimetry. Of the systems available, the fluoroscopic camera-based EPID Theraview (InfiMed Inc.) has not been studied to date, and a review of the dosimetric properties of the system is presented here. In the "single set-up" mode of image acquisition, pixel intensity increases sublinearly with applied dose. The response was dependent on the system's video signal gain and showed a threshold dose to the detector in the range 0.05-0.35 cGy, and pixel saturation at detector doses in the range 1.2-1.6 cGy. Repeated exposures of the EPID were observed to be extremely reproducible (standard deviation 0.5%). The sensitivity of the system showed a linear decline of 0.04% day-1 over a 68-day period, during which time the relative off-axis response within 10 x 10 cm2 field was constant to within a standard deviation of 0.56%. The system shows spatial non-uniformity, which requires correction for application to dose measurements in two-dimensions. Warm-up of the camera control unit required a period of at least 40 min and was associated with an enhancement in pixel intensity of up to 12%. A radiation dose history effect was observed at doses as low as 0.2 Gy. Camera dark current was shown to be negligible at normal accelerator operation. No discernible image distortion was found. Mechanical stability on gantry rotation was also assessed and image displacement of up to 5 mm at the isocentre was observed. It was concluded that the device could be used for dosimetry provided necessary precautions were observed and corrections made.
A collision prevention software tool for complex three-dimensional isocentric set-ups.
Authors: Beange I , Nisbet A
Published: June 2014

During treatment planning it can be difficult to check whether a particular plan is workable, that is it avoids obstructing treatment beams with parts of the patient couch and it avoids collisions between the treatment machine head and the patient couch. To overcome this problem, the trigonometric relationships between the placement of treatment beams and the patient couch are examined. From these relationships a set of useful equations that can be generally applied is derived. The application of these equations practically as a simple (non-graphical) planning tool is described. The resulting tool enables the feasibility of a plan to be checked during treatment planning, and gives guidance as to how a patient could be repositioned to allow the use of a plan when potential beam obstructions are detected, prior to verification of the treatment on a simulator.
CT findings in post-operative subphrenic abscess with teratomatous inclusions.
Authors: Lindbichler F , Raith J , Tillich M , Sorantin E , Riccabona M , Geyer G
Published: June 2014

A 39-year-old woman presented with abdominal pain after tubal sterilization. CT showed a subphrenic abscess with fatty inclusions owing to laceration or rupture of a mature ovarian teratoma. Although subphrenic abscess is a well recognized post-operative complication, and ovarian teratomas are frequent, a teratomatous inclusion within a subphrenic abscess is a unique finding.
Acute radiation-induced hepatic injury: evaluation by triphasic contrast enhanced helical CT.
Authors: Willemart S , Nicaise N , Struyven J , van Gansbeke D
Published: June 2014

We report a case of radiation-induced hepatic injury as a complication of localized abdominal radiotherapy for epidural spread of non-Hodgkin's lymphoma. The liver was evaluated by triphasic contrast enhanced helical CT scan. Hepatic biopsy demonstrated changes typical of veno-occlusive disease. The pattern of hepatic enhancement resulting from the radiation-induced veno-occlusive process is discussed.
Bilateral radical radiotherapy in a patient with uterus didelphys.
Authors: Lee C D , Churn M , Haddad N , Davies-Humphries J , Kingston R K , Jones B
Published: June 2014

We report a case of congenital abnormality of uterus didelyphys in a patient who developed invasive carcinoma of the cervix. She received radical radiotherapy by a combination of external beam pelvic radiotherapy and high dose rate brachytherapy by insertion of afterloading catheters into both uterine canals. A newly defined prescription point was used midway between the two catheters and 2 cm above the mean cervical os position. The classical point A was regarded as inappropriate in this patient with a rare condition. Acute toxicity was minor and the patient is tumour free with no significant normal tissue late effects after follow-up of nearly 3 years.
Systemic and regional haemodynamic effects of aortofemoral angiography.
Authors: Bardelli M , Fazio M , Cominotto F , Pozzi Mucelli F , Stacul F , Fabris B , Fischetti F , Ricci C , Carretta R
Published: June 2014

The aim was to investigate the regional and systemic haemodynamic consequences of bolus injection of fluids with different physical properties in the course of routine aortography. Iopamidol was compared with an equiosmolar solution of mannitol and with a 0.9 N saline solution. Continuous blood flow and Pulsatility Index (PI), as an index of regional vascular resistance, were measured by Doppler technique. Finger arterial pressure and heart rate were monitored at the time and for 3 min following each intraaortic bolus injections. The patients who underwent routine aortography were grouped according to the site of the flow measurements: common femoral artery, common carotid artery and brachial artery. Flow changes induced by the bolus infusion were evident for all the fluids but only at the femoral artery level. After an immediate (3 +/- 2 s) and brief (2 +/- 2 s) but marked reduction of flow and in-phase increase of PI following the bolus, further haemodynamic changes were observed only in the femoral artery, with a peak at 35 +/- 10 s and returning to baseline values after 70 +/- 15 s, in terms of both increased mean blood velocity and decreased PI. Saline and mannitol induced overall blood velocity alterations of 54% and 80%, respectively, and PI reductions of 44% and 57% compared with those induced by iopamidol. In the other vascular areas there was only a 17 +/- 2% increase of the physiological early diastolic backflow at the brachial artery level. Blood pressure decreased and heart rate increased in phase with the flow changes of the femoral artery. In conclusion: (1) a dramatic rheodynamic perturbation at the site of injection induces a vasodilating stimulus; (2) the haemodynamic response following injection results in marked vasodilation of only the tributary vascular bed; (3) flow steal may occur from other beds towards the lower limb vascular beds owing to vascular impedance imbalance; (4) a reduction of systemic arterial pressure is induced in phase with the regional vascular events and a reflex increase of the heart rate; and (5) the physical properties of the injected fluids influence the intensity of the perturbation, although the decisive triggering factor is the counterflowing bolus per se.
The value of intubation dacryocystography after dacryocystorhinostomy.
Authors: Amin M , Moseley I F , Rose G E
Published: June 2014

We retrospectively reviewed 104 dacryocystograms carried out on 72 patients who had previously undergone dacryocystorhinostomy, to assess the diagnostic contribution of the radiological investigation in patients with persistent or recurrent symptoms. In patients whose symptoms were referable to the operated side, dacryocystography was performed as part of further pre-operative assessment. In 42% of these patients it demonstrated an anatomical or physiological abnormality that explained the symptoms. However, no clear reason for the recurrence of symptoms was demonstrated in 58% of cases.
A comparison of fixed and variable kVp technique protocols for film-screen mammography.
Authors: McParland B J , Boyd M M
Published: June 2014

Mammographic image quality, contrast and dose for a variable tube potential (kVp) technique protocol for film-screen mammography have been investigated. In this protocol, the tube potential is increased for larger breast thicknesses. Comparisons were made with fixed kVp protocols, in which the tube potential is kept constant and the breast thickness compensated for by prolonging the exposure ("fixed kVp" protocol). All measurements were performed on a mammography unit with a molybdenum target and filter. Image quality was quantified by image contrast, image detail detection and the minimum detectable dimension of low contrast objects. It was demonstrated that for a compressed breast thickness of less than about 40 mm, varying the tube potential had a negligible effect upon dose but a significant effect upon image quality. For a compressed breast thickness greater than about 60 mm, the effect of the tube potential upon image quality was much reduced; however, the effect upon dose was significantly greater. The variable kVp protocol takes advantage of this feature to yield a significantly lower dose for thicker breasts with a small reduction in image quality, often only within experimental uncertainty. For an exposure under automatic exposure control, increasing the tube potential from 26 kVp to 30 kVp for a breast of a reference tissue composition (50% adipose and 50% glandular) with a compressed thickness of 60 mm reduced the mean glandular dose from 6 mGy to 3.9 mGy (-35%), but increased the minimum detectable dimension of a low contrast mass from 0.8 (+/- 0.1) mm to 1.1 (+/- 0.1) mm. Adopting a variable kVp protocol led to a median patient mean glandular dose per film of 2.7 mGy, nearly independent of compressed breast thickness. In our survey, the mean age of women presenting for mammography is younger and the mean compressed breast thickness is less than reported from screening centres. This suggests that there will be a higher proportion of denser, glandular tissue in the breasts incorporated within this survey than for surveys from screening centres. The clinical use of the variable kVp protocol allows the extraction from patient data of separate changes in breast composition which are due to patient age and breast thickness. It is concluded that the reference breast tissue composition is not an accurate representation of the women presenting at this centre.
The need for the moving junction in craniospinal irradiation.
Authors: Kiltie A E , Povall J M , Taylor R E
Published: June 2014

The moving junction is used in craniospinal irradiation (CSI) to smooth out any dose inhomogeneity across the head/spine junction. The aim of this study was to demonstrate the extent of the head/spine junction inhomogeneity in treatment plans of actual patients and to compare stationary and moving junction data. The radiotherapy plans, prescriptions and case notes of 18 patients (12 medulloblastomas, 3 supratentorial primitive neuroectodermal tumours, 2 pineoblastomas and 1 pineal germinoma) treated with CSI (35 Gy in 21 fractions over 29 days) were examined. At 16 months median follow-up (range 1.5-35.5 months), no junctional recurrences or myelopathy were observed. Using the moving junction technique the mean maximum anterior cord dose, from 5 cm caudal to 3 cm cephalad of the Day 1 junction, was 36.3 Gy, and the mean minimum anterior cord dose was 32.9 Gy, with a mean within-patient variation of 3.4 Gy (9.7% of 35 Gy). In four patients, comparison of dose variation across the field junction was made between the original plans and a re-plan using a stationary junction. The effect of a matched junction, a 2 mm overlap and a 2 mm gap were studied both for moving junction and stationary junction techniques. Dose variations were similar in all cases for exactly-matched fields, but for a 2 mm overlap or gap the dose variation was smaller in all but one case for the moving junction technique. These data suggest that the moving junction is important to minimize the risk of overdose or underdose across the spine/head junction in CSI.
Intraosseous pneumatocyst of the scapula.
Authors: Kamba M , Ohuchi Y , Ogawa T , Ohata R
Published: June 2014

Intraosseous pneumatocyst is a gas-containing cyst-like lesion that occurs most frequently in the ilium, sacrum or vertebrae. We present a case involving the left scapula that was found incidentally on CT. To our knowledge, intraosseous pneumatocyst of the scapula has not been previously reported.
Perianal mucinous carcinoma successfully treated with a combination of external beam radiotherapy and high dose rate interstitial brachytherapy.
Authors: Nishimura T , Nozue M , Suzuki K , Imai M , Suzuki S , Sakahara H , Nakamura T , Sugimura H
Published: June 2014

The case of an 84-year-old man with perianal mucinous carcinoma is presented. The tumour was 6 cm in diameter and extended into the surrounding tissues. Taking the patient's advanced age and disease into account, rectosigmoidectomy and colostomy were carried out without resection of most of the tumour. Radiotherapy consisted of pre-operative external beam radiotherapy (EBRT) of 40 Gy in 20 fractions, post-operative EBRT of 24 Gy in 12 fractions, and high dose rate interstitial brachytherapy of 12 Gy in a single fraction. The patient tolerated the entire course of radiotherapy well. The patient is doing well without regrowth or complications 7 years after radiotherapy. To our knowledge, there have been no reports on the successful outcome of radiotherapy for perianal mucinous carcinoma. This case suggests that a combination of EBRT plus interstitial brachytherapy boost may play a role in the definitive treatment of perianal mucinous carcinoma.
The benefit of stereology for quantitative radiology.
Authors: Roberts N , Puddephat M J , McNulty V
Published: June 2014

A knowledge of stereology (i.e. proper sampling), the opportunities provided by computers for image analysis (i.e. image segmentation, image registration, data base exploration, 3D reconstruction), and the strengths (i.e. non-invasive) and limitations (i.e. finite resolution, image artefacts) of medical imaging equipment must all be combined for reliable quantitative magnetic resonance imaging (MRI), the goal of which is to obtain a deeper understanding of the structure, function, life cycle and evolution of the human body, especially the brain, and a more objective diagnosis of disease and assessment of its response to treatment. In this article we illustrate the first of these requirements. We describe the application of proper sampling strategies and efficient computer-based counting procedures for obtaining unbiased estimates of volume by the Cavalieri method and of surface area from vertical sections. In particular, we estimate the volume of a brain tumour from Cavalieri sections, the volume of grey matter in the cerebral hemispheres from Cavalieri slices and the surface area of the cerebral cortex from vertical sections. The estimates obtained are mathematically unbiased. In each case, we assess the precision of the estimates empirically. Application of formulae available for predicting the precision of volume estimates obtained using the Cavalieri sections and slices methods is also described.
Spiral CT optimization for measurement of bronchial lumen diameter using an experimental model.
Authors: Edwards P D , Bull R K , Brown V S , Curtin J
Published: June 2014

The aim of the study was to determine optimal parameters for demonstrating sublobar bronchi on spiral CT. Measurements were obtained from five parallel polyethylene tubes embedded in foam matrix with similar radiographic characteristics to segmental and subsegmental bronchi and to lung parenchyma, respectively. Collimation widths of 1.5, 2, 3 and 4 mm were used, with a pitch of 1 or 1.5 and a reconstruction interval of 1 mm or 2 mm. Various slice planes were used. Images acquired orthogonally were viewed normally. Images acquired in planes oblique or parallel to the long axes of the tubes were reformatted into a plane orthogonal to the long axes of the tubes to be comparable with the directly acquired orthogonal images. Tube diameters were measured at lung window settings (L, -400; W, 1300) and compared with known true inner and outer tube diameters. Measurements from images acquired orthogonal to the tube long axes were accurate regardless of slice thickness. Images acquired obliquely or parallel only produced accurate measurements at the lowest slice thickness (1.5 mm). Pitch and reconstruction interval had no effect on measurement error in any scan plane. It is concluded that a slice thickness of 1.5 mm or less, with a pitch of 1.5, should be used when acquiring images at angles other than orthogonal to the long axes of experimental tubes equivalent to the segmental and subsegmental bronchi. It is suggested that similar parameters should be used in vivo and that the examination should be targeted to the area of the bronchial tree in question to reduce patient dose and length of breath-hold.
The aetiology of non-tumorous enhancement in the hepatic hilum shown on CT hepatic arteriography.
Authors: Yamagami T , Arai Y , Inaba Y , Matsueda K , Takeuchi Y , Nishimura T
Published: June 2014

The causes of non-tumorous abnormalities in the hepatic hilum seen on CT hepatic arteriography were investigated. 13 patients with non-tumorous defects of portal perfusion in the hepatic hilum on CT arterial portography underwent both CT hepatic arteriography from the common hepatic artery and CT obtained during proper hepatic arteriography. The findings of non-tumorous portal defects on these two angiographic studies using helical CT were compared. In the 13 patients, 14 non-tumorous defects of portal perfusion in the hepatic hilum on CT arterial portography were detected as enhanced areas in 10 regions (dorsum of segment IV, 7/10; dorsum of the lateral segment, 3/4) on CT hepatic arteriography via the common hepatic artery, but none were enhanced on CT obtained during proper hepatic arteriography. In conclusion, the main cause of non-tumorous enhancement in the hepatic hilum seen on CT hepatic arteriography is non-portal direct inflow via the parabiliary venous system.
MRI appearances of bladder endometriosis.
Authors: Umaria N , Olliff J F
Published: June 2014

Endometriosis is characterized by endometrial tissue in ectopic foci outside the uterus. Involvement of the urinary tract is rare, with the bladder being most commonly affected in these cases. Radiologically these lesions, which are usually small, may be difficult to distinguish from intrinsic bladder neoplasia. Four cases of vesical endometriosis are presented with the MRI features that suggest the diagnosis.
Single dose irradiation response of pig skin: a comparison of brachytherapy using a single, high dose rate iridium-192 stepping source with 200 kV X-rays.
Authors: Hamm P C , Bakker E J , van den Berg A P , van den Aardweg G J , Visser A G , Levendag P C
Published: June 2014

An experimental brachytherapy model has been developed to study acute and late normal tissue reactions as a tool to examine the effects of clinically relevant multifractionation schedules. Pig skin was used as a model since its morphology, structure, cell kinetics and radiation-induced responses are similar to human skin. Brachytherapy was performed using a microSelectron high dose rate (HDR) afterloading machine with a single stepping source and a custom-made template. In this study the acute epidermal reactions of erythema and moist desquamation and the late dermal reactions of dusky mauve erythema and necrosis were evaluated after single doses of irradiation over a follow-up period of 16 weeks. The major aims of this work were: (a) to compare the effects of iridium-192 (192Ir) irradiation with effects after X-irradiation; (b) to compare the skin reactions in Yorkshire and Large White pigs; and (c) to standardize the methodology. For 192Ir irradiation with 100% isodose at the skin surface, the 95% isodose was estimated at the basal membrane, while the 80% isodose covered the dermal fat layers. After HDR 192Ir irradiation of Yorkshire pig skin the ED50 values (95% isodose) for moderate/severe erythema and moist desquamation were 24.8 Gy and 31.9 Gy, respectively. The associated mean latent period (+/- SD) was 39 +/- 7 days for both skin reactions. Late skin responses of dusky mauve erythema and dermal necrosis were characterized by ED50 values (80% isodose) of 16.3 Gy and 19.5 Gy, with latent periods of 58 +/- 7 days and 76 +/- 12 days, respectively. After X-irradiation, the incidence of the various skin reactions and their latent periods were similar. Acute and late reactions were well separated in time. The occurrence of skin reactions and the incidence of effects were comparable in Yorkshire and Large White pigs for both X-irradiation and HDR 192Ir brachytherapy. This pig skin model is feasible for future studies on clinically relevant multifractionation schedules in a brachytherapy setting.
Acute appendicitis presenting with a testicular mass: ultrasound appearances.
Authors: Satchithananda K , Beese R C , Sidhu P S
Published: June 2014

Acute appendicitis presenting with scrotal symptoms is a rare event, occurring when a patent processus vaginalis persists. We present a case where ultrasound demonstrated an inflamed appendix and a scrotal abscess, allowing the correct surgical management in a difficult clinical situation. In a child presenting with scrotal signs and vague lower abdominal symptoms, an ultrasound assessment of the right iliac fossa should always be performed.
MR findings of subarachnoid dissemination of a pituitary adenoma.
Authors: Matsuki M , Kaji Y , Matsuo M , Kobashi Y
Published: June 2014

Although pituitary adenoma is a benign tumour, subarachnoid dissemination occurs rarely. We describe a case of pituitary adenoma with subarachnoid dissemination. After the third operation for pituitary adenoma, an extraaxial mass was demonstrated on MR images. On T1 and T2 weighted images, the signal intensities of the extraaxial mass were similar to those of the primary pituitary adenoma. On dynamic contrast T1 weighted images, the time-intensity curve of the extraaxial mass, which showed early and persistent signal intensity, was also similar to that of the primary pituitary adenoma. These MR findings are considered to reflect the similar vascularity and stroma of the extraaxial mass and the primary pituitary adenoma.
CT diagnosis of malpositioned chest tubes.
Authors: Gayer G , Rozenman J , Hoffmann C , Apter S , Simansky D A , Yellin A , Itzchak Y
Published: June 2014

Insertion of a chest tube into the pleural space is standard management for various pleural disorders. Malpositioning of chest tubes in extrathoracic, intraparenchymal and mediastinal locations and in the fissures is common. Malpositioning results not only in inadequate drainage of air and fluid but may also result in increased morbidity and mortality. Diagnosis of a malpositioned tube is sometimes difficult to establish on a chest radiograph. CT, however, has proven to be extremely accurate in evaluating the position of a chest tube and has often provided additional valuable information with significant therapeutic impact.
MRI of the breast.
Authors: Rankin S C
Published: June 2014

MRI of the breast is rapidly evolving as a sensitive technique for the detection and staging of breast cancer. It has considerable benefits but is time consuming and expensive. The benefits and limitations of this technique are presented.
Value of spiral CT in patients with cricothyroid approximation.
Authors: Pickuth D , Brandt S , Neumann K , Berghaus A , Spielmann R P , Heywang-Köbrunner S H
Published: June 2014

Cricothyroid approximation raises the vocal pitch by simulating contraction of the cricothyroid muscle with sutures. The aim of this study was to determine the role of spiral CT in patients scheduled for cricothyroid approximation. 29 transsexual patients were examined with spiral CT prior to and after laryngoplastic surgery. CT findings were correlated with phonographic findings in all patients. The average reduction of the cricothyroid distance was 6 mm (range 2-10 mm). Vocal pitch elevation was greatest in patients with the largest reduction of the cricothyroid distance. CT accurately determines the cricothyroid distance prior to and after surgery and is an ideal method for follow-up, especially in post-operative reversion towards a lower pitch. In addition, CT provides important data in determining the most appropriate extent and site of intracordal intervention to achieve a desired pitch elevation.
Accurate measurement of exposure rate from a 60Co teletherapy source: deviations from the inverse-square law.
Authors: Samat S B , Evans C J , Kadni T , Dolah M T
Published: June 2014

A cylindrical gamma-ray 60Co source of activity alpha is predicted to produce an exposure rate X at a distance d in vacuum, given by X = gamma(T)(alpha/d2), where gamma(T) is the specific gamma-ray constant. It has been documented that this formula may be used to approximate X with an accuracy of 1% from a source of length l, provided that d/l > or = 5. It is shown that the formula is accurate to 0.1% under these conditions, provided that the distance is measured from the centre of the source. When absorption in the source and scattering in the collimator are considered, the position of the origin d = 0 can shift by a distance of the order of centimetres. Absorption in air between the source and the ionization chamber adds an exponential factor to the formula. It is shown that even when these modifications are included the discrepancy in the results, although generally less than 1%, is still large compared with the measurement errors. Some suggestions are made for the origin of this discrepancy.
Radiography for midfacial trauma: is a single OM 15 degrees radiograph as sensitive as OM 15 degrees and OM 30 degrees combined?
Authors: McGhee A , Guse J
Published: June 2014

Two previous studies have suggested that a single occipitomental (OM) 15 degrees radiograph may be sufficient for screening for midfacial fractures in the Accident and Emergency (A&E) department, but the study had insufficient power to detect whether some fractures might be missed with only one projection. We undertook to determine whether there is a decreased sensitivity for detecting fractures if only a single OM 15 degrees radiograph is used rather than OM 15 degrees + 30 degrees. 44 cases of major and minor midfacial fractures interspersed randomly with 49 cases of facial injury without fracture were shown to nine A&E clinicians. Initially they were shown only the OM 15 degrees radiograph, then the OM 30 degrees radiograph alone, and then the two radiographs together. They were asked each time to indicate the presence or absence of fracture. The sensitivity for the OM 15 degrees projection alone was 89.4%, and when both radiographs were used it was 90.9% (difference not significant). Given the positive yield of facial radiographs is only 6%, any minimal increase in sensitivity from using two projections is likely to be outweighed by the beneficial reduction in X-ray exposure and costs from using only a single projection. The policy of using a single OM 15 degrees radiograph as a screening tool for midfacial fractures in A&E is a safe one.
Dose equivalents of tumour repopulation during radiotherapy: the potential for confusion.
Authors: Dale R G , Jones B , Sinclair J A
Published: June 2014

When employing linear quadratic equations to calculate compensation for changes in overall treatment time, a potential confusion exists regarding use of the parameter commonly described as the dose equivalent of tumour repopulation. The more correct term for this factor is the biologically effective dose equivalent of tumour repopulation. The distinction between the two concepts is discussed and the potential errors arising from their confusion are illustrated by means of an example.
Conservative surgery and radiation therapy for early stage breast cancer after previous mantle radiation for Hodgkin's disease.
Authors: Aref I , Cross P
Published: June 2014

There is an increased incidence of breast cancer in female patients who have previously undergone mantle radiation for Hodgkin's disease. Lumpectomy followed by breast irradiation is generally considered to be contraindicated in such patients owing to the high cumulative radiation dose to the breast. Mastectomy is therefore recommended as the preferred treatment option in these women. We report two cases of breast cancer occurring in women previously treated with mantle radiation for Hodgkin's disease. Both women declined mastectomy and requested breast-conserving treatment.
Impact of motion artefact on the measurement of coronary calcium score.
Authors: Brown S J , Hayball M P , Coulden R A
Published: June 2014

Reports have shown that total coronary calcium (CC) measured by electron beam CT (EBCT) correlates well with atheroma extent, and this in turn is a reliable indicator of risk for future ischaemic events. Although total CC may be measured using a conventional CT scanner, image quality is degraded by cardiac motion artefact. Errors in CC measurement owing to slice misregistration between adjacent breath-holds affect both conventional CT and EBCT. The latest generation conventional CT scanners have acquisition times of 500 ms or shorter, and, when combined with ECG triggering, quantitative CC measurement without reliance upon EBCT becomes a real possibility. We investigated the effect of motion on the measured calcium score using a moving phantom. Our results show that use of ECG triggering with conventional CT improves reproducibility of Agatston calcium score measurement. Increasing motion time during image acquisition results in an apparent increase in the Agatston CC score. Alternative measures of the amount of CC may be less susceptible to motion-induced bias, but have a similar reproducibility.
Change in oxygenation status in intratumour total and quiescent cells following gamma-ray irradiation, tirapazamine administration, cisplatin injection and bleomycin treatment.
Authors: Masunaga S , Ono K , Hori H , Suzuki M , Kinashi Y , Takagaki M , Kasai S , Nagasawa H , Uto Y
Published: June 2014

C3H/He mice bearing SCC VII tumours received 5-bromo-2'-deoxyuridine (BrdU) continuously for 5 days via implanted mini-osmotic pumps to label all proliferating (P) cells. The mice then received gamma-ray irradiation, or administration of tirapazamine (TPZ), cisplatin or bleomycin. At various time points after each treatment, tumour-bearing mice were irradiated with a series of test doses of gamma-rays, while alive or after being killed, to obtain hypoxic fractions (HFs) in the tumours. Immediately after gamma-ray test irradiation, the tumours were excised, minced and trypsinized. Tumour cell suspensions obtained were incubated with cytochalasin-B, a cytokinesis blocker, and the micronucleus (MN) frequency in cells without BrdU labelling (i.e. quiescent (Q) cells) was determined using immunofluorescence staining for BrdU. MN frequency in the total (P + Q) tumour cells was determined from the tumours that were not pre-treated with BrdU. MN frequency of BrdU-unlabelled cells was then used to calculate the surviving fraction of the unlabelled cells from the regression line for the relationship between the MN frequency and the surviving fraction of total tumour cells. TPZ and cisplatin reduced the HF after treatment, especially in Q cells, and this tendency was particularly marked with TPZ. In contrast, bleomycin increased the HF after treatment. Both reoxygenation following gamma-ray irradiation or bleomycin treatment and a subsequent return to pre-treatment levels of HF following TPZ or cisplatin treatment (rehypoxiation) occurred more rapidly in total (P + Q) cells than in Q cells. Based on our previous report that total (P + Q) and Q cells within this tumour have large acutely and chronically HFs, respectively, we conclude that acute hypoxic cells play a major role in reoxygenation and rehypoxiation in SCC VII tumours.
An audit of outcome of adjuvant post-operative radiotherapy for 52 women with stage II carcinoma of the endometrium.
Authors: Blake P , Lodge N , A'Hern R P
Published: June 2014

A retrospective review was undertaken of the medical records of 52 women with stage II carcinoma of the endometrium who received adjuvant radiotherapy following surgery. The information was obtained from medical notes and a hospital database. Actuarial disease-free survival was 68% at 5 years for those women with stage IIA disease, and 70% at 5 years for those women with stage IIB disease. 6 of the women (11.5%) had side effects from treatment. In contrast to the literature, the only statistically significant prognostic factor in this study was histological differentiation; patients with poorly differentiated tumours fared worse (p = 0.05). This may indicate that a greater number than 52 women is needed to demonstrate weaker prognostic factors such as substage. A larger review is being undertaken of the remaining women recorded on the database, with stage I, III and IV disease.
GSM cell phones can interfere with ionizing radiation dose monitoring equipment.
Authors: Gilligan P , Somerville S , Ennis J T
Published: June 2014

Cell phone use is growing worldwide. These phones transmit to adjacent base stations using radiofrequency signals in the microwave range (approximately 900-approximately 1800 MHz). Portable electronic dose monitoring equipment is used in hospitals and other institutions to monitor and control levels of exposure to ionizing radiation, and to reassure staff. The objective of this paper is to investigate the effect of mobile phones on a sample of dose monitoring devices. Two mobile phones (Siemens C25 and Motorola CD930) were used in the study. Field strengths were measured to be in the range 0 V m-1 to over 100 V m-1, depending on the distance from the phone, and were strongest at the beginning of a call. Personal electronic dosemeters (n = 7), portable dose monitors (n = 4) and contamination monitors (n = 2) were assessed. All the units were in service. Three of the personal dosemeters showed abnormal responses when exposed to mobile phone transmission. One dosemeter (Siemens EPD-2) registered doses equivalent to a dose rate of 99 mSv h-1. In addition, two of the portable dosemeters and one of the contamination monitors also gave an abnormal response. Interference was observed across a number of detector types from a number of manufacturers. Modern cell phones can interfere with ionizing radiation dose monitoring equipment. This should be taken into account when distributing these devices and when assessing results generated by them. Electromagnetic compatibility testing should form part of the commissioning and specification protocol for new dose monitoring equipment.
Communication of doubt and certainty in radiological reports.
Authors: Hobby J L , Tom B D , Todd C , Bearcroft P W , Dixon A K
Published: June 2014

We have investigated the reliability of communication of uncertainty in radiological reports. The 18 most commonly used verbal expressions of probability were identified from a series of radiological reports. 11 clinicians (three radiologists, three rheumatologists and five orthopaedic surgeons) recorded the probability that they ascribed to each of the 18 expressions using visual analogue scales. Each subject was re-tested on four occasions at least 1 week apart. The results were analysed to assess reproducibility within and between individuals. We found considerable variation in the probabilities assigned to many commonly used expressions between subjects, and between repeated testing of the same subject. Some expressions were rated much more consistently than others. "Absent", "excludes", "unlikely", "probable", "certain" and "definite" were the most consistently rated expressions. We have identified a potential source of misunderstanding in radiological reports owing to differences in interpretation of expressions used by radiologists and referring clinicians.
Malignant stromal tumour of the rectum: findings at endorectal ultrasound and MRI.
Authors: van den Berg J C , van Heesewijk J P , van Es H W
Published: June 2014

This case report describes the findings on endorectal ultrasound and MRI in a patient with a giant malignant stromal tumour of the rectum. A review of imaging characteristics and histopathological findings as described in the literature is presented.
Extensive soft tissue uptake of 99Tcm methylene diphosphonate in a patient with multiple myeloma.
Authors: Evans J C , Murphy M , Eyes B
Published: June 2014

Bone scintigraphy is not usually performed in multiple myeloma (MM), as marrow deposits characteristically show no tracer uptake. However, metastatic bone disease often mimics MM both clinically and biochemically, resulting in a substantial number of MM patients undergoing bone scintigraphy. Variable appearances in these cases have been reported, ranging from normal to a superscan, the latter a result of massive tracer uptake within bone. Soft tissue uptake has been documented, often when MM is complicated by secondary amyloidosis. This usually results in mainly solid organ uptake of tracer. We report a case of MM where massive soft tissue uptake occurred, primarily within muscles, with very little isotope elsewhere.
Vertigo after stapes surgery: the role of high resolution CT.
Authors: Pickuth D , Brandt S , Berghaus A , Spielmann R P , Heywang-Köbrunner S H
Published: June 2014

CT findings in patients with vertigo after stapes surgery include a prosthesis shaft entering the vestibule and compressing the saccule, a complete dislocation of the stapes prosthesis, air bubbles and fluid collections within the vestibule and outside the oval window indicating a perilymphatic fistula, and bony fragments leading to compression of the basal saccule. Although immediate post-operative vertigo is often transient, patients with persistent or recurrent vertigo should be imaged as high resolution CT will determine the underlying cause in the majority of cases.
Increased hepatic arterial blood flow after decreased portal supply to the liver parenchyma owing to intrahepatic portosystemic venous shunt: angiographic demonstration using helical CT.
Authors: Yamagami T , Arai Y , Takeuchi Y , Nakamura T , Inaba Y , Matsueda K , Nishimura T
Published: June 2014

This study was conducted to investigate the haemodynamics of the liver parenchyma in the presence of intrahepatic portosystemic venous shunt. 3 patients with intrahepatic portosystemic venous shunts and 24 patients with normal intrahepatic haemodynamics underwent both CT arterial portography and CT during hepatic arteriography. Angiographic findings with helical CT were compared, and CT attenuated values were measured in both groups. The liver parenchyma on CT arterial portography had lower attenuation than on CT during hepatic arteriography in all patients with intrahepatic portosystemic venous shunts. Overall average CT attenuation was 92.2 +/- 7.7 Hounsfield units (HU) on CT arterial portography and 149.9 +/- 8.5 HU after CT during hepatic arteriography, with the opposite findings in all patients without intrahepatic portosystemic venous shunt: CT attenuation 142.0 +/- 25.7 HU on CT arterial portography and 100.7 +/- 16.4 HU after CT during hepatic arteriography. In conclusion, the portal venous supply to the liver parenchyma decreased due to intrahepatic portosystemic venous shunts, with a compensatory increase in hepatic arterial blood supply.
Crohn's disease of aphthous type: serial changes in intestinal lesions.
Authors: Matsumoto T , Iida M , Nakamura S , Hizawa K , Yao T , Fujishima M
Published: June 2014

In Crohn's disease (CD), aphthous lesions are regarded as possible precursors of typical intestinal involvement. To determine the natural course of intestinal lesions in CD of aphthous type, the clinical course of 10 patients was retrospectively investigated during a period ranging from 6 to 16 years after diagnosis. The criterion for inclusion was confirmed aphthous lesions within the gastrointestinal tract with histologically verified epithelioid granuloma. The degrees of aphthous lesions in the small intestine and the colon were graded by small bowel radiography, barium enema examination and colonoscopy. Five patients developed typical CD during a period ranging from 0.8-3.3 years. The site of involvement was the ileum in three patients, the colon in one patient and both the ileum and the colon in one patient. Typical small intestinal CD occurred in four of seven patients with marked aphthous lesions of the small intestine, whereas colonic CD occurred in two of eight patients with such aphthous lesions of the colon. These findings suggest that CD of aphthous type is not necessarily a precursor of clinically overt disease. This may especially be the case for colonic aphthous lesions.
Image quality and dose in film-screen magnification mammography.
Authors: McParland B J
Published: June 2014

Extended exposure times in magnification mammography are a result of the reduced X-ray tube currents required for a small focal spot. The consequences of this are the potential for reduced image quality through motion blur during exposure as well as the onset of film reciprocity law failure. Previous investigators have suggested increasing the X-ray tube potential as a practical mechanism for reducing exposure times in magnification mammography and have demonstrated negligible image quality degradation at least up to 32 kVp. This paper describes a film-screen magnification mammography study that expands upon this previous work to investigate the magnitude of the reduction of breast mean glandular dose and exposure time and the changes in subjective image quality (visibility of low contrast details in an RMI 152 phantom) with increases in tube potential between 28 kVp and 35 kVp. Measures of changes in the radiographic contrast and in the scatter-to-primary ratio (SPR) in magnification geometry as a function of tube potential were also obtained. Evidence for reciprocity law failure was also assessed. For a constant film optical density, increasing the X-ray tube potential from 28 kVp to 35 kVp reduced the mean glandular dose from 3.9 mGy to 2.7 mGy and reduced the exposure time from 3.2 s to 1.0 s. Over this range, the detection rate of fibrils and microcalcification-mimicking specks did not vary with tube potential at the 0.05 level of significance. It was found that only the low contrast mass detail detection rate at 35 kVp was significantly less than that at 28 kVp. The measured radiographic contrast decreased with tube potential and the SPR increased with tube potential. However, both changes were weak, and linear regressions determined that the 95% confidence intervals of the slopes relating both contrast and SPR with tube potential encompassed zero. It is concluded that magnification mammography performed at 34 kVp yields significant reductions in exposure time and mean glandular dose, with a detail detection capability similar to that at 28 kVp.
Morphological study of the femur in osteopetrotic (op/op) mice using microcomputed tomography.
Authors: Abe S , Watanabe H , Hirayama A , Shibuya E , Hashimoto M , Ide Y
Published: June 2014

Osteopetrosis is an inherited metabolic disorder in which normal bone remodelling is inhibited. Its primary cause is considered to be disruption of the functional balance between osteoblasts and osteoclasts as well as a reduction in the quantity of osteoclasts. The purpose of this study was to observe morphological characteristics of the femur in osteopetrotic (op/op) mice, in which the pathogenic mechanism of osteopetrosis has been shown to operate, using microcomputed tomography (micro-CT), in addition to macro-anatomical observations. Previously, micro-CT has been used mainly for morphometry of a small portion of cancellous bone. However, with recent improvements it has become possible for three-dimensional (3D) observations of bone using slightly larger samples to be made. In this study, the accuracy of reconstructed 3D images of the femur produced by micro-CT was confirmed by comparison with the original femur. In addition, an arbitrary cross-section could be displayed on the screen for detailed examination of its internal structure, and the volume percentage of trabecular bone in a particular region of interest could be measured in three dimensions. The results of this study revealed that the femur was smaller and malformed in the op/op mouse compared with the controls, and the differences were greater at the age of 18 weeks than at 5 weeks. In the control mice, bone marrow occupied a large space in the centre of the body of the femur, whereas this area was occupied by calcified bone tissue in the mutant mice. Moreover, when 3D bone density was measured in the region of interest, the value was greater in the mutants than in the controls at both 5 weeks and 18 weeks of age. This study also showed that micro-CT can be applied to 3D morphometric analyses.
Fluid collections detected by ultrasound following uncomplicated colorectal surgery.
Authors: Miliaras S , Beveridge E , Campbell C , Sunderland G , MacDonald A
Published: June 2014

The aim of the study was to assess the incidence and site of intraperitoneal fluid collections following uncomplicated colorectal surgery and to identify factors relating to the presence of such collections. 38 patients (22 males) with a mean age of 67 years (range 38-85 years) undergoing uncomplicated colorectal procedures were studied prospectively. Patients underwent abdominal and pelvic ultrasound on Day 3 and Day 7 following surgery. The number, site and volume of collections were recorded. Ultrasound-detected fluid collections were present in 26% on Day 3 and 25% on Day 7 following laparotomy. The presence of a collection was not related to the amount of residual volume after peritoneal lavage with normal saline prior to operative closure, to intraoperative blood loss or to the presence of drains. The right upper quadrant was the commonest site of intraperitoneal collections. In the absence of additional clinical signs, the presence of such collections is not an indication for intervention.