bluuebunny/crossref_metadata_2025 huggingface dataset:
Eutectoid Transformation in Zn-Al Alloys Solidified by Rapid Cooling
Authors: Peter Ildiko , Varga Béla , Rosso Mario
Published: May 2014

Rapid solidification represents a very attractive approach to develop new Al alloys in an economically convenient way. The lower segregation content, refined grains, higher ultimate tensile and yield strengths combined to a good ductile properties confer to these materials an interesting position also in the so critical automotive and/or aeronautical applications. The current paper presents results of an analysis concerning Zn-Al alloys with a new metastable microcrystalline structure, where Copper has been used as alloying element. With addition of elements as Ti and B modification of the microstructure has been reached. In order to study the influence of the cooling rate on the microstructure and structural transformations castings has been realized with melt spinning technique, in both steel and sand moulds. For morphological investigations optical and scanning electron microscopy has been employed. By dilatometric analysis and X-Ray diffraction technique the thermodynamic factors, the kinetic effects, phase transformations and the volume changes related to the transformations produced at the eutectoid temperature have been monitored. For the aforementioned field of applications the most favourable composition has been chosen: based on the up to date outcomes, by modifying the original alloy with some elements a quite homogeneous structure combined with good mechanical behaviour has been obtained.
Liquidus Temperature Calculation in Sn-Bi-Cd System by ESTPHAD Method
Authors: Tatárka Eszter , Mende Tamás , Roósz András
Published: May 2014

This paper includes the binary and ternary liquidus temperature calculations of Sn-Bi-Cd system. The calculation was performed in cases of the surfaces of Sn, Bi and Cd phases too. First of all the liquidus curves were calculated in the binary systems (Bi phase in Bi-Cd and Bi-Sn systems, Sn phase in Sn-Cd and Sn-Bi systems, Cd phase in Cd-Sn and Cd-Bi systems). By using the calculated coefficients of the binary phase diagrams and the data from the digitalized ternary phase diagram, the liquidus temperature of Sn, Bi and the Cd phases were calculated. Finally the eutectic point of the binary liquidus curves and the eutectic valley of the Sn and the Bi surfaces were calculated by means of an iteration method.
A Numerical Benchmark Test for Continuous Casting of Steel - II
Authors: Šarler Božidar , Vertnik Robert
Published: May 2014

There is a continuously developing need for benchmarking of solidification simulations - from the theoretical [1] as well as from the applied [2] points of view. The history of related benchmarking shows differences of the results between different numerical methods, and differences in comparison with the experiments when solving even quite simple solidification situations. The present benchmark test proposes macrosegregation [3] upgrades to the verification benchmark for continuous casting of steel, first presented in [2]. The paper represents guidelines for the presentation of the numerical method, discretisation and results and shows a reasonable comparison between a commercial finite volume based code and our in-house developed meshless method based code.
In Situ Particle Layer Formation in a Al-Mn-Si Ternary Eutectic Alloy: Ground Reference and Microgravity Experiments
Authors: Zhou Bin , Froyen Ludo
Published: May 2014

A special type of divorced eutectic growth mode (symbiotic growth) in a ternary Al-Mn-Si alloy, triggered by addition of titanium boride (TiB2) has been studied under both ground and microgravity conditions. During directional solidification, α (AlMnSi) particles nucleate ahead of the planar solidification front and are pushed and later engulfed by the interface forming a banded particle layer structure. The presence of fine titanium boride particles (clusters) in front of the growing α (AlMnSi) particles makes the interaction between the intermetallic α (AlMnSi) particles and solidification front much more complex than most proposed models for particle/interface interactions. Microgravity experiments can eliminate the gravity related effects and thus provide an opportunity to better understand the formation mechanism of symbiotic growth. In this study, hypoeutectic Al-1Mn-3Si alloys with addition of 0.33 wt% TiB2 were directionally solidified in ESA Solidification and Quenching Furnace (SQF) on board of the International Space Station (ISS). The ground experiment was conducted in a replica of this furnace prior to the microgravity experiments. Non-destructive X-ray tomography and its 3D reconstruction software was used to characterize the particles and their distribution. Comparison between ground and microgravity experiment results is presented. The particle pushing and engulfment of symbiotic growth is discussed based on a particle pushing and engulfment model.
ESA's Cooperative Strategy and Current Program in Materials Science in Space
Authors: Voss Daniela
Published: May 2014

The physical sciences research activities implemented by ESA in the framework of the European Life and Physical sciences in Space (ELIPS) programme build up on more than two decades of scientific progress and experience with developing and operating instruments on various space carriers. Research projects are mostly defined and developed in the context of International Topical Teams supported by ESA in coordination with other international partner agencies. Formal project proposals are eventually submitted to regular Announcements of Opportunity, reviewed by international independent peers and their technical feasibility is assessed by technical experts of the facilities considered for the implementation of the space experiments. For most projects, experiments and numerical modelling go hand in hand. As concerning Materials Sciences and the realisation of solidification experiments several platforms and facilities are utilised. This spans from centrifuges to - with increasing experiment duration - the Drop Tower in Bremen, the A-300 aircraft flying parabolic trajectories, sounding rockets and eventually the International Space Station (ISS). Several solidification instruments from typical Bridgman type furnaces to electromagnetic levitation and heating of spherical samples were developed, some of which are already operational in orbit. A dedicated X-ray set-up has also recently been operated on a sounding rocket to enable in-situ observations of the solidification of a metallic alloy. The paper will provide an overview of solidification projects, their objectives and corresponding instruments available for experimentation. It will lay out the objectives and strategy of ESA’s research programme, including the consolidating the international cooperation that prevails in Europe and in the ISS project.
Identification of Grain Boundary Segregation Mechanisms during Silicon Bi-Crystal Solidification
Authors: Autruffe Antoine , Friis Jesper , Vines Lasse , Arnberg Lars , di Sabatino Marisa
Published: May 2014

Small angle grain boundaries have been grown in a small Bridgman furnace, using seeded growth method, at three different pulling rates i.e. 3 μm/s, 13 μm/s and 40 μm/s. In order to assess segregation mechanisms of impurities towards the central grain boundary, melt has been polluted by 50ppma of either copper or indium. Secondary ion mass spectrometry (SIMS) local analyses have been performed to investigate the impact of solid state diffusion and limited rejection of solute at the grain boundary for each growth rate. The results are discussed in connection with an atomistic model built on Vienna Ab-initio Simulation Package (VASP).
Three Dimensional Morphology of Mn Rich Intermetallics in AlSi Alloys Investigated with X-Ray Tomography
Authors: Mikolajczak Piotr , Ratke Lorenz
Published: May 2014

Elementary Mn has a great importance as neutralizer of Fe intermetallics like β-Al5FeSi, which have detrimental effect on mechanical characteristics of AlSi alloys. Presence of Mn in AlSi alloys causes the formation of other intermetallic phases. To understand the effect of solidification conditions and fluid flow on the microstructure of AlSi-based alloys and the addition of Mn leading to Mn-based intermetallics, Al-5 wt pct Si 0.2/0.4/1.0 wt pct Mn alloys have been directionally solidified under defined thermal (gradient 3 K/mm, solidification velocity 0.02-0.12 mm/s) and fluid flow (rotating magnetic field 6 mT) conditions. The primary Al-phase and Mn-based intermetallic phases were studied using 3D X-ray tomography. The spatial morphology of primary phase and intermetallics were characterized with respect to different fluid flow and solidification conditions. The tomography has showed the 3D complicated structure of Mn phases developed.
Phase Field Modeling of β(Ti) Solidification in Ti-45at.%Al: Columnar Dendrite Growth at Various Gravity Levels
Authors: Viardin Alexandre , Sturz Laszlo , Apel M. , Hecht Ulrike
Published: May 2014

At present, our understanding of the interaction between melt flow and solidification patterns is still incomplete. In columnar dendritic growth buoyancy driven flow may alter the dendrite tip and spacing selection and consequently the microsegregation of alloying elements. With the aim of supporting directional solidification experiments under hyper-gravity using a large diameter centrifuge (LDC), phase field simulations of β (Ti) dendrite growth have been performed under various gravity conditions for the binary alloy Ti-45at.%Al. The results show that Al segregation at the growth front causes convection rolls around the dendrite tips. The direction of the gravity vector is an essential parameter. When g is opposite to the direction of dendrite growth, increasing gravity leads to a marked decrease of the primary dendrite spacing and to a decrease of the mushy zone length. When g is aligned parallel to the direction of dendrite growth, the primary dendrite spacing and mushy zone length are almost unchanged, however the secondary dendrite arms grow more prominently as the magnitude of g increases.
Solidification of Bulk Lamellar Eutectics
Authors: Hecht Ulrike , Witusiewicz Victor , Rex Stephan
Published: May 2014

Eutectic alloys from the ternary system Al-Cu-Ag are excellent model alloys for the investigation of coupled eutectic growth, not only because most materials properties are well known but also because the system offers a rich variety of crystal structures and crystal orientation relationships (ORs) being associated to distinct minima of the solid-solid interface energy. This paper describes three research topics specifically related to bulk lamellar Al-Al2Cu eutectics, e.g. the maze-to-lamellar transition during early growth, the role of fault lines during lamellar spacing selection close to the pinch-off limit and the onset of eutectic cell formation above the constitutional supercooling limit. These topics are central to the microgravity experiments SETA presently being prepared for the MSL / SQF.
Unidirectional Solidification of Pb-Sn Alloys in a Rotating Magnetic Field
Authors: Kovács Jenő , Rónaföldi Arnold , Roósz András
Published: May 2014

Cylindrical Pb-Sn alloy samples (diameter: 8 mm, length: 120 mm) of different compositions (30, 40 and 50 wt.% of Sn) were prepared from high pure (4N) components. The unidirectional solidification experiments have been performed according to the upward vertical Bridgman-method by using a rotating magnetic field (RMF) with a magnetic induction of 150 mT and with a frequency of 50 Hz. The sample-movement velocity was constant (0.05 mm/s) and the temperature gradient changed from 7 to 3 K/mm during the solidification process. The first half of samples was solidified without using the magnetic field and the second half was solidified by using the magnetic field. Under the influence of this strong flow induced by the magnetic field, the columnar microstructure of the first part decomposed and a characteristic "Christmas tree"- like macrosegregated structure with equiaxed Pb-dendrites was developed. The secondary dendrite arm spacing (SDAS) and the volume percent of primary Pb-phase (dendrite) were measured by an automatic image analyser on the longitudinal polished sections along the whole length of the samples. The effect of the forced melt flow on the micro-and macrostructure was studied in case of the different sample compositions.
A Possible Mechanism for the Formation of Exploded Graphite in Nodular Cast Irons
Authors: Gerghu Roxana , Magnusson Åberg Lena , Lacaze Jacques
Published: May 2014

In hypereutectic nodular cast irons, primary precipitation of graphite may lead to graphite flotation in thick section castings. Graphite degeneracy such as so-called exploded graphite is then often associated with this flotation phenomenon and it appears as precipitates where the nodular form is replaced by star-like or flower-like shape. It has been reported that exploded graphite develops after the primary spheroidal nodules have reached some tens of microns in diameter. In this contribution, a model for this transition is presented.
Cast Iron Solidification Structure and how it is Related to Defect Formation
Authors: Elmquist Lennart , Soivio Kaisu , Diószegi Attila
Published: May 2014

In this work, the meaning of the solidification structure and how it is related to defect formation in grey cast iron will be discussed. The work also confirms observations made earlier. In previous work the formation of shrinkage porosity in grey cast iron cylinder heads was investigated. It was found that the defect is located around solidification units resembling primary austenite grains. The solidification of grey cast iron starts with the formation of primary austenite grains, followed by the eutectic solidification. The primary grains nucleate and grow either as columnar or equiaxed grains, creating a columnar to equiaxed transition between the two zones. Based on the presence of a migrating hot spot, and other characteristics found on the cylinder heads, a geometry was developed that promote the formation of shrinkage porosity. The primary solidification structure, normally transformed during the solid state transformation, was preserved using a technique called Direct Austempering After Solidification (DAAS). After solidification, the samples were cut and prepared for investigation using a Scanning Electron Microscope (SEM) equipped with a detector for Electron Back Scattered Diffraction (EBSD). Individual grains were identified and the primary solidification structure around the defects was revealed. The investigation shows how shrinkage porosity is formed and located between primary austenite grains. This confirms that the primary solidification structure has a large influence on the formation of defects in grey cast iron. The investigation also confirms the correctness of earlier results as well as the validity of the DAAS technique.
Graphite Growth Morphologies in Cast Iron
Authors: Muhmond Haji Muhammad , Fredriksson Hasse
Published: May 2014

Graphite growth morphology was studied by using InLense detector on FEG-SEM after performing ion etching on the samples. Star like and circumferential growth mechanism of graphite was observed in the graphite nodules. Pure ternary alloy of hypo eutectic and hyper eutectic composition was treated with pure Mg, Ca and Sr, to study the effect of O and S concentration in the melt, on the transition of graphite morphology from nodular to vermicular/compacted and flake graphite. The change in the melt composition between the austenite dendrites due to micro-segregation of S, O and inoculants and their possible effects on the transition of graphite morphologies as well as the nucleation of new oxides/sulfides particles is discussed with the help of thermodynamics.
Modelling of Al-7%wtSi-1wt%Fe Ternary Alloy: Application to Space Experiments with a Rotating Magnetic Field
Authors: Budenkova Olga , Baltaretu Florin , Steinbach Sonja , Ratke Lorenz , Roósz András , Rónaföldi Arnold , Kovács Jenõ , Bianchi Anna Maria , Fautrelle Yves
Published: May 2014

Recently several experiments on directional solidification of Al-6.5wt.Si-0.93wt.%Fe (AlSi7Fe1) alloy were performed under terrestrial conditions and onboard the International Space Station (ISS) in the Materials Science Lab (MSL) with use of electromagnetic stirring and without it. Analysis of the samples showed that stirring with a rotating magnetic field lead to the accumulation of iron-rich intermetallics in the center of the sample and influenced the primary dendrite spacing while the secondary dendrite arm spacing were not affected. In the present paper the accumulation of the intermetallics b-Al5SiFe in the center of the samples due to RMF stirring is demonstrated numerically and the evolution of primary and secondary dendrite arm spacing is discussed.
Analysis of the Antimony and Strontium Cross-Effects in Al-Si Foundry Alloys
Authors: Tokár Monika , Fegyverneki György , Mertinger Valéria
Published: May 2014

In this work we show the effect of various concentrations of strontium and antimony on the level of modification in the Al-Si alloy. The scale of the modification rate was determined in two ways: thermal analysis was performed and the images of the samples. The eutectic temperature registered during the analysis were compared to the eutectic temperature of the unmodified alloy and on the basis of them was determined which samples are registered as modified, which are not. On the basis of the results of the cooling curves the partially modified category was introduced, if the ΔT value is less than 9°C and more than 7.5°C. The samples made of the alloys were examined with a computer image analysis and the samples were grouped on the basis of the size of the eutectic silicon phases. The aim of our research work was the examination of cross-effects of strontium and antimony.
Mechanical Behavior of Novel Suction Cast Ti-Cu-Fe-Co-Ni High Entropy Alloys
Authors: Samal Sumanta , Mohanty Sutanuka , Misra Ajit Kumar , Biswas Krishanu , Govind B.
Published: May 2014

The present investigation reports mechanical properties of novel multicomponent TixCuyFe20Co20Ni20 high entropy alloys (HEAs) with different alloy chemistry (x/y = 1/3, 3/7, 3/5, 9/11, 1, 11/9 and 3/2). The alloy cylinders were prepared by vacuum arc melting-cum-suction casting route. The detailed electron microscopic observations reveal the presence of three different solid solution phases; FCC (a1) phase, FCC (a2) phase and BCC (b) phase for all the investigated alloys, whereas ultrafine eutectic between FCC (a1) phase, and Ti2 (Co, Ni) - type Laves phase has been observed for the HEAs with x/y = 9/11, 1, 11/9 and 3/2. Room temperature compression test of the suction cast cylinders with aspect ratio of 2/1 has been conducted to obtain mechanical properties of the HEAs. The optimum combination of strength (~ 1.88 GPa) and plasticity (~ 21 %) is obtained for x/y = 9/11; indicating simultaneous improvement of strength as well as plasticity of the novel HEAs. Fractographic analysis of the fractured surfaces reveals mixed mode of fracture for x/y = 1/3, 3/7 and 3/5, ductile mode for x/y = 9/11 and 1, whereas brittle mode of fracture for x/y = 11/9 and 3/2.
Microgravity and Hypergravity Observations of Equiaxed Solidification of Al-Cu Alloys Using In Situ X-Radiography Recorded in Real-Time on Board a Parabolic Flight
Authors: Murphy Andrew G. , Li J. , Janson Olle , Verga Antonio , Browne David J.
Published: May 2014

During solidification of metallic alloys, thermosolutal natural convection plays a significant role in grain nucleation, subsequent growth and morphology, as well as the formation of casting defects. In this work, an Al-5wt%Ti-1wt%B inoculated Al-20wt%Cu alloy was solidified, near-isothermally, using a Bridgman-type gradient furnace, while being monitored in real-time via in-situ X-radiography as part of a parabolic flight microgravity campaign. Each parabola consisted of a transition through 24 seconds of hypergravity (1.8 g), followed by 22 seconds of microgravity, and a then a further 24 seconds of hypergravity. Solidification was controlled such that nucleation occurred coincident with the onset of microgravity. This allowed for the effects of microgravity on equiaxed nucleation and initial growth, followed by continuing solidification in hypergravity, to be observed, as well as the effect on the semi-coherent grain structure when transitioning between the two.
3D reconstruction of base metal zoning in the Flin Flon - Callinan-777 volcanogenic massive sulfide deposits, Manitoba
Authors: Byron J , Schetselaar E , Gibson H , Pehrsson S , Lafrance B , Devine C , Ames D
Published: May 2014

This document reports the spatial distribution of Cu- versus Zn-rich lenses in the Flin Flon, Callinan and 777 volcanogenic massive sulphide deposits of the Paleoproterozoic Flin Flon Belt, Manitoba. Their relative distribution can be used to locate hydrothermal
vent sites in VMS deposits that contain multiple sulphide lenses or deposits. Using historical and modern assay datasets, a 3D Gocad model characterizing the spatial relationships between Cu and Zn concentrations was constructed. The model shows that the Cu-rich zones decrease in size from the base
to the top of the Flin Flon and 777 deposits, which is consistent with upward and outward zone-refining of the sulphide lenses. The Cu-rich zones are typically elongate parallel to the topology of the sulphide lenses, which are shaped as flattened ellipsoids that plunge parallel to a pronounced
regional stretching lineation. A second, less distinct trend is oriented oblique to the stretching lineation, in both the Flin Flon and 777 deposits. The Flin Flon and 777 deposits have at least three and two distinct Cu-rich zones, respectively, suggesting the presence of separate hight-T
hydrothermal vents. The Callinan deposit does not contain a Cu-rich zone, but is slightly more Cu-rich towards its south end. The deposit shows an overall decrease in Cu/Zn ratios from south to north as well as a localized decrease northerly around the interpreted vent. The Callinan ore lenses are
interpreted as a clastic sulphide deposit fringing the Zn-rich shell of the 777 deposit possibly derived by mass wasting of sulphide mounds and mass flow transport of sulphide clasts during periods of tectonic instability. A lateral Zn variation is also present and suggests input of additional
metals from one or more separate vents located north of the Callinan deposit.
Metastatic calcification as a result of extensive bone metastases in a paediatric patient with Parameningeal Embryonal Rhabdomyosarcoma
Authors: Ismail Farzanah , Lockhat Zarina , Sathekge Mike , Khan Nausheen , Van de Werke Irma
Published: May 2014

We present a case of Parameningeal Embryonal Rhabdomyosarcoma with the primary lesion arising in the middle and inner ear, with associated diffuse skeletal metastases and metastatic calcifications.
Accuracy of MRCP compared to ERCP in the diagnosis of bile duct disorders
Authors: Hurter Delmé , De Vries Coert , Potgieter Pierre , Barry Renald , Botha Frikkie , Joubert Gina
Published: May 2014

AIM: To determine the accuracy of Magnetic Resonance Cholangiopancreatography compared to the gold standard Endoscopic Retrograde Cholangiopancreatography in the diagnosis of bile duct disorders at our institution. PATIENTS AND METHODS: 52 patients with suspected pancreatobiliary pathology were included in this prospective observational study. MRCP was performed in the 24-hour period prior to the ERCP. RESULTS: MRCP had sensitivity, specificity, positive and negative predictive values of 87%, 80%, 83.3% and 84.2% respectively for choledocholitiasis which correlates well with results obtained in other parts of the world. CONCLUSION: At our institution, MRCP has high diagnostic accuracy for bile duct calculi. Due to a small study population, results for other biliary pathology were inconclusive
PET-CT meltdown is looming
Authors: Lotz Jan
Published: May 2014

No abstrac available.
Protein-losing enteropathy demonstrated on Tc-99m HSA
Authors: Mpikashe P , Sathekge M M , Meyer B J
Published: May 2014

No abstrac available.
Conned by Conn’s Syndrome
Authors: Ismail F , Lockhat Z , Ellemdin S , Van der Linde L
Published: May 2014

Conn’s Syndrome is a rare entity amongst hypertensive patients and imaging of the aldosterone producing adenoma (APA) can prove challenging but is none the less very important for surgical planning and cure. We present two patients with MRI confirmation of APA with negative and equivocal computed tomography (CT) scans.
CPD Questionnaire
Authors: Fani Gertrude
Published: May 2014

No abstract available.
Response assessment in lymphoma with PET/CT
Authors: Moller J S , Basson J I , Du Toit P D , Bonnet S , Heyns G F
Published: May 2014

No abstact available.
Staging of breast cancer with PET/CT
Authors: Moller J S , Pieterse W H , Du Toit P D , Bonnet S , Diedericks A , Brummer W
Published: May 2014

No abstact available.
CPD Questionnaire
Authors: Fani Gertrude
Published: May 2014

No abstact available.
MRI signal changes in the liver following multiple transfusions.
Authors: Durand M , Abrahams J C
Published: May 2014

Diffuse signal changes in the liver on MRI often represent a depositional process with decreased signal when iron or copper is deposited or increased signal with fatty deposition. We present a 68y male with myelodysplasia requiring multiple blood transfusion, resulting in such signal changes.
The many faces of hydatid disease
Authors: Lawson A , Parrish A
Published: May 2014

No abstact
Leri-Weill dyschondrosteosis: An under-recognised cause of short stature
Authors: Lemire E G , Wiebe S
Published: May 2014

Short stature is a frequent presenting problem in the pediatric population. Various causes including endocrinopathies, skeletal dysplasias, dysmorphic syndromes and malabsorption have been implicated. In girls with short stature, Turner syndrome is frequently considered in the differential diagnosis and can easily be ruled out with chromosome analysis. However, it is not uncommon for a child to have no identifiable cause of their short stature. ?FOR Advances in the field of genetics have estimated that about 2% of idiopathic short stature is related to haploinsufficiency of the Short stature homeobox (SHOX) gene, which is found on the short arm of the X and Y chromosomes in the pseudoautosomal region. Heterozygous carriers of SHOX mutations may be minimally affected or may present with disproportionate short stature, Madelung deformity and other radiographic findings as in Leri-Weill dyschondrosteosis (LWD). In this article, we report on a 14-year old girl with mesomelic short stature and bilateral Madelung deformities caused by LWD and describe the radiographic findings.
A dose audit of fluoroscopy examinations at Charlotte Maxeke Johannesburg Academic Hospital: Analysis of preliminary results
Authors: Nyathi T , Pule M L , Segone P , Van der Merwe D G , Rapoho S P
Published: May 2014

Purpose: To retrospectively analyze the radiation doses delivered to patients undergoing fluoroscopy examinations in terms of the skin dose and the dose-area product (DAP). Materials and Methods: The subjects of this study were patients who underwent fluoroscopy examinations at Charlotte Maxeke Johannesburg Academic Hospital, South Africa during the period August 2007 to March 2008. The skin dose and dose-area product values were obtained from a built-in DAP-meter installed on a digital Philips Medical Systems MultiDiagnost Eleva fluoroscopy unit. The following cases were analyzed namely barium swallow, barium meal, barium enema, hexabrix swallow, gastrografin meal, voiding cystourethrogram, fistulogram, myelogram, nephrostomy and loopogram. Results: An analysis of three hundred and thirty one examinations is presented. From the recorded data the following quantities were deduced: the mean- and range of the skin doses and DAPs, mean screening time and mean fluoroscopy duration. An analysis of the screening time for the various examinations showed a weak correlation (r = 0.59) between skin dose and screening time, while a poor correlation (r = 0.42) was deduced between DAP reading and screening time. Conclusion: There is a wide spread in the radiation doses registered for any one given type of examination. The large variability in the radiation dose delivered proves that fluoroscopic examinations stand to gain from dose optimization. The usefulness and potential use of DAP meters with regards to dose optimization in radiology is shown. In line with efforts to optimize dose from diagnostic radiography examinations the authors recommend the establishment of diagnostic reference levels (DRLs) in South Africa for the most frequent examinations in general radiography, fluoroscopy, mammography and computed tomography. Keywords: patient dose, genetic risk, dose optimization, dose reference levels
Spinal segmental dysgenesis
Authors: Mahomed N , Naidoo J
Published: May 2014

Spinal segmental dysgenesis is a rare congenital spinal abnormality , seen in neonates and infants in which a segment of the spine and spinal cord fails to develop normally . The condition is segmental with normal vertebrae above and below the malformation. This condition is commonly associated with various abnormalities that affect the heart, genitourinary, gastrointestinal tract and skeletal system. We report two cases of spinal segmental dysgenesis and the associated abnormalities.
Infantile Sandhoff's disease
Authors: Sass K , Wiebe S , Lemire E
Published: May 2014

Case based review of the rare autosomal recessive disease. Clinical and Radiological features described in detail.
A pilot study evaluating erect chest imaging in children, using the Lodox Statscan digital X-ray machine
Authors: Daya Rupesh Baloo , Kibel Maurice A , Pitcher Richard Denys , Workman Lesley , Douglas Tania S , Sanders Virginia
Published: May 2014

ABSTRACT

Background:

Chest radiography accounts for a significant proportion of ionising radiation in children. The radiation dose of radiographs performed on the Lodox Statscan system has been shown to be lower than that of a computed radiography (CR) system. The role of the Lodox Statscan (hereafter referred to as the Statscan) in routine erect chest radiography in children has not been evaluated.

Objective:

To evaluate the image quality and diagnostic accuracy of erect paediatric chest radiographs obtained with the Statscan and compare this with conventional erect chest images obtained with a CR system.

Materials and Methods:

Thirty three children with suspected chest pathology were enrolled randomly over a period of three months. Erect chest radiographs were obtained with the Statscan, and a Shimadzu R-20J X-ray machine coupled with a Fuji FCR 5000 CR system. Image quality and diagnostic accuracy and diagnostic capability were evaluated between the two modalities.

Results:

The erect Statscan allowed superior visualisation of the three major airways. Statscan images however, demonstrated exposure and movement artifacts with hemidiaphragms and ribs most prone to movement. Bronchovascular clarity was also considered unsatisfactory on the Statscan images.

Conclusion:

The Statscan has limitations in erect chest radiography in terms of movement artefacts, exposure fluctuations, and poor definition of lung markings. Despite this, the Statscan allows better visualisation of the major airways, equivalent to a ‘high KV’ film at a fraction of the radiation dose. This supports the finding of an earlier study evaluating Statscan images in trauma cases, where the images were taken supine. Statscan has great potential in assisting in the diagnosis of childhood tuberculosis where airway narrowing occurs as a result of nodal compression.
Chilaiditi's syndrome demonstrated by SPECT/CT
Authors: Perumal Nalini S , Vangu Mboyo-Di-Tamba H , Purbhoo Khushica , Dhoodhat Shireen
Published: May 2014

Purpose: Chilaiditi’s syndrome is a rare condition commonly diagnosed as an incidental radiological finding. The aim of this report is to show the role of SPECT-CT in this syndrome and state the functional and anatomical role of this hybrid imaging modality.

Materials and Methods: A case report.

Results: A 49-year-old female patient was referred for gallium-67 citrate for a possible

granulomatous myositis and underwent SPECT-CT of the abdomen to assess the area of decreased gallium uptake on planar images of the liver. The combined SPECT and CT modality demonstrated findings consistent with the clinical evidence of Chilaiditi’s syndrome. The anatomical part of this hybrid modality made it easier to evaluate the area of gallium lack of uptake which was due to air in the colon.

Conclusion: This case does not only show the role of SPECT-CT in this syndrome but also suggest that the use of such modality should be considered whenever available in the evaluation of patients in whom the localization of active disease becomes imperative.
Multiple aneurysms due to intimomedial mucoid degeneration: a short presentation
Authors: Gajjar H , Beningfield S J , Naidoo N G , Motala Ahmed
Published: May 2014

A 17 year-old female presented with abdominal pain, due to contained rupture of a left common iliac artery aneurysm. This was accompanied by abdominal aortic and superior mesenteric artery aneurysms. Despite emergency vascular surgery, the patient died a week later. Post-mortem examination revealed intimomedial mucoid degeneration. This rare condition has been described predominantly in South African black patients especially females, and occurs at a younger age than degenerative aortic aneurysms.
The enigma of reversible spinal lesions
Authors: Misser Shalendra Kumar , Royston Duncan , Motala Farhana , Coetzee Christo
Published: May 2014

Abstract

Focal reversible lesions of the splenium of the corpus callosum have been described in a number of clinical paradigms. Epilepsy and related conditions are the most commonly reported underlying clinical association. Sudden anti-epileptic therapy withdrawal or seizure activity may be presumed to be the predisposing cause, however an individual susceptibility must also be considered. Herein, we present the findings in two patients with similar, completely reversible splenial lesions.
Infra-cardiac totally anomalous pulmonary venous drainage
Authors: Dahya V
Published: May 2014

None
The HPCSA and radiology
Authors: Van Niekerk JP
Published: May 2014

There is general agreement that adequate radiation control is essential. But in my opinion there are more important issues that were not in the remit of the committee, namely the proliferation of many diagnostic and therapeutic interventions that are reliant on expensive equipment. Such equipment is often acquired because of its potential revenue generation and that often results in self-referral – a sure way of driving up medical costs through unnecessary procedures.
Radioactive News
Authors: Sperryn C
Published: May 2014

N/A
Continuing medical education in Radiology in South Africa
Authors: Janse van Rensburg Leon
Published: May 2014

N/A
Mermaid baby
Authors: Khan N , Ismail F , Van de Werke I , Gongxeka H
Published: May 2014

We were recently intrigued by a baby born at Kalafong Hospital with fused lower extremities resembling a mermaid, which caused us to search for the background and origin of this entity called sirenomelia.
Musculoskeletal case - findings and diagnosis
Authors: Misser S K
Published: May 2014

N/A
Cardiac case - new
Authors: Misser S K
Published: May 2014

N/A
Reports on the second RSSA short course on Current Ethical Issues in Radiology, the first RSSA/SGR Gastrointestinal Radiology Course, and abstracts of oral presentations at the first RSSA/SGR GI Radiology Course
Authors: Beningfield S
Published: May 2014

N/A
Molecular imaging
Authors: Bury Bob
Published: May 2014

N/A
Cardiovascular magnetic resonance imaging - a pictorial review
Authors: Dahya Vijay , Spottiswoode Bruce S
Published: May 2014

Cardiovascular magnetic resonance imaging (CMR) is a powerful problem-solving tool and arguably offers the most comprehensive assessment of cardiac morphology and function, as well as the opportunity of rebuilding the bridge between cardiologists and radiologists. The role of CMR-trained imaging physicists is also valuable, and many CMR centres harmoniously incorporate these three sub-specialty fields.

This paper comprises an overview of several CMR techniques, outlining both the strengths and limitations of the modality.
Digital teaching files – a useful teaching tool for the modern radiologist
Authors: Du Plessis Andre Tertius
Published: May 2014

Radiologists have always collected copies of model examples and interesting cases encountered in daily practice to use for teaching purposes. A collection of teaching files is an important resource for medical education and the dissemination of knowledge in radiology. Furthermore, the presence of a radiological teaching file is also a requirement at several universities and tertiary institutions in South Africa and abroad, where radiology postgraduate training is conducted.

The advent of digital radiology and the more widespread use of picture archiving and communication systems (PACS) have led to a unique opportunity to change the way that radiology teaching cases are collected, stored and managed. Traditional teaching file systems are rapidly becoming obsolete and incompatible with the digital environment of modern radiology departments.
Diabetic mastopathy: A clinical and radiological challenge
Authors: Meerkotter Debra Ardath , Rubin Grace
Published: May 2014

A 41-year-old woman presented with a lump above the right areola. She also complained of a burning and heavy sensation of the right breast of recent onset. On further history, the patient was an insulin-dependent diabetic of 35 years’ duration. She had no family history of breast disease. On examination, a palpable thickening above the right areola was detected.

Bilateral mammography revealed dense fibro-glandular tissue, denser in the right retro-areolar region than the left, with right peri-areolar skin thickening. There was no discreet mass nor suspicious microcalcifications or axillary adenopathy. Ultrasound (US) demonstrated an ill-defined peri-areolar region of decreased echogenicity and posterior shadowing. Core biopsy under US guidance showed abundant thick collagen bands containing epitheloid fibroblasts and a stroma with small capillary-sized and larger muscularised blood vessls, some of which contained peri-vascular lymphocytic inflammatory cells. Small ductal elements and an occasional lobule showed a peri-ductal and a peri- and intra-lobular lymhocytic and plasma cell infiltrate. These features were in keeping with sclerosing lymphocytic mastitis, known also as diabetic mastopathy.
Report-back by 2009 RSSA Travel Award Winer
Authors: Janse van Rensburg Pieter
Published: May 2014

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Contents
Authors: Matzdorff Robert
Published: May 2014

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Idiopathic granulomatous mastitis
Authors: Rubin Grace , Meerkotter Debra Ardath
Published: May 2014

The rare condition of idiopathic granulomatous mastitis (IGM) is presented here, unusually, in a 54-year-old woman. IGM mimics breast carcinoma and further differentials include tuberculosis and fungal infections of the breast together with other chronic granulomatous conditions. Of note is its characteristic ultrasound features that can suggest the diagnosis. Diagnosis is made by core biopsy and histology. Patients have been shown to respond to steroid and other immunosuppressive therapy, with surgical excision reserved for those whose condition is recurrent and unresponsive to medical treatment.
Unilateral membranous choanal atresia
Authors: Ahmed Aadil
Published: May 2014

Images of a case of unilateral choanal atresia diagnosed in a 35-year-old woman are presented. This is an uncommon diagnosis in an adult patient, and a less frequently encountered form of the condition. In more than 90% of cases of choanal atresia, the abnormality is partly or completely osseous; pure membranous atresia is rare. It is unilateral in 50 - 60% of cases, and more than 75% are associated with syndromes and systemic anomalies.
Rethinking responsibility in radiography: Some ethical issues in South Africa
Authors: Etheredge Harriet Rosanne
Published: May 2014

The field of radiography in South Africa is complex and presents a multitude of ethical issues. The discipline is often regarded as a supporting function in the healthcare chain, and a stepping-stone in the diagnostic process. This status of the discipline seems to have left many radiographers in a position of substantial confusion. In the course of numerous bioethics presentations for radiographers in South Africa, several ethical and legal issues have recurrently come to my attention. This article aims to address some of these issues and to offer ethically and legally acceptable solutions. The proposed solutions are not absolute – they are based on personal discussions and experiences – and their practicability needs to be scrutinised. Consequently, this article should be seen as a starting point only.
Complications, disease profile and histological yield from percutaneous renal biopsy under real-time US guidance: A retrospective analysis
Authors: Kruger M , Loggenberg E
Published: May 2014

Objective. The objective of the study was to evaluate (i) the technique used at Universitas Hospital in comparison with other international centres also performing renal biopsies, (ii) the disease profile in patients undergoing renal biopsies, (iii) the complications experienced during and/or after the procedure, and (iv) the histological yield of the biopsies (amount of nephrons per biopsy taken) using this technique.

Design. A retrospective descriptive analysis of all patients who underwent percutaneous renal biopsy under ultrasound (US) guidance at the Interventional Radiology Unit, Universitas Hospital, Bloemfontein, was undertaken for the period 1 January 2003 - 31 December 2008. Data obtained from the patients’ files and histology reports were statistically analysed.

Results. A total of 112 patients qualified for inclusion in the study, all of whom had proof of renal failure and then had percutaneous renal biopsy performed under US guidance. The histology was diagnostic in 111 (99.1%) of the cases, with more than 5 nephrons present in 105 (93.5%) of the cases. Minor complications were found in 29 (25.8%) of the patients, but no major complications were noted. Primary renal disease was found in 67 (59.8%) of patients, and the renal pathology and failure in 45 (40.2%) of the patients were shown histologically to be owing to systemic disease.

Conclusion. The technique utilised for performing percutaneous renal biopsy under US guidance at the Interventional Radiology Unit was shown to be safe, with a diagnostic histological yield comparable with international standards. A small majority or patients suffered primary renal disease in comparison with renal failure owing to systemic illness.
Musculoskeletal diagnosis
Authors: Misser S K
Published: May 2014

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MDCT/CTA essentials course, Report by ESOR musculoskeletal visiting scholarship
Authors: Janse van Rensberg Leon
Published: May 2014

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A severe case of astrogliosis and encephalomalacia in a neonate with a massive vein of Galen malformation (VGM)
Authors: Ismail F , Khan N , Van de Werke I , Ahmed R
Published: May 2014

Vein of Galen malformations (VGMs) are rare anomalies of intracranial circulation that constitute 1% of all intracranial vascular malformations. We describe a case of severe encephalomalacia associated with a VGM, which has not been previously described.
RSSA council and EXCO 2011 - 2013; congress and workshop reports; Travel Award report-back; RSSA book donations and academic prizes; neuroradiology subgroup
Authors: Lotz Jan
Published: May 2014

RSSA council and EXCO 2011 - 2013; congress and workshop reports; Travel Award report-back; RSSA book donations and academic prizes; neuroradiology subgroup
Arm pain after syncope - new case
Authors: Misser S
Published: May 2014

Arm pain after syncope - new case
Establishing a quality assurance baseline for radiological protection of patients undergoing diagnostic radiology
Authors: Korir Geoffrey K , Wambani Jeska Sidika , Korir Ian K
Published: May 2014

Background. The wide use of ionising radiation in medical care has resulted in the largest man-made cause of radiation exposure. In recent years, diagnostic departments in Kenya have adapted the high-speed film/screen combination without well-established quality control, objective image quality criteria, and assessment of patient dose. The safety of patients in terms of justification and the as-low-as-reasonably-achievable (ALARA) principle is inadequate without quality assurance measures.

Aim. This study assessed the level of film rejects, device performance, image quality and patient dose in 4 representative hospitals using high-speed film/screen combination.

Results. The X-ray equipment quality control tests performance range was 67% to 90%, and 63% of the radiographs were of good diagnostic value. The measured prevalent chest examination entrance surface dose (ESD) showed levels above the international diagnostic reference levels (DRLs), while lumbar spine and pelvis examination was the largest source of radiation exposure to patients.

Conclusion. The optimisation of patient protection can be achieved with optimally performing X-ray equipment, the application of good radiographic technique, and continuous assessment of radiographic image quality.
Pseudomyxoma peritonei (PMP) - a rare entity
Authors: Ebrahim Zaeem Ismail , Lockhat Zarina Ismail , Ismail Farzanah
Published: May 2014

Pseudomyxoma peritonei (PMP) is a rare complication of mucinous tumours of appendiceal or ovarian origin that results in peritoneal and omental implants. Clinical morbidity and mortality arise from the fact that copious amounts of extracellular and peritoneal mucin result in distortion and loss of function of visceral organs. Therapeutic paracentesis is not possible because of the nature of the mucin. Currently, new techniques are being used to attempt to debulk the mucin volume; none, however, has lead to superior outcome.
Multiple skeletal lesions and pleural effusion owing to Histoplasma capsulatum infection in an immunocompetent patient from a non-endemic region
Authors: Suleman Farhana Ebrahim , Scheepers Pieter Albrecht
Published: May 2014

We describe a rare case of multiple skeletal lesions and a pleural effusion owing to Histoplasma capsulatum infection in a 16-year-old immunocompetent girl residing in a non-endemic region. Of note is that the patient had a lesion within a thoracic vertebra. Following an extensive literature search, we found that vertebral involvement by H. capsulatum had not been previously described. Pleural effusion and skeletal lesions are both rare manifestations of H. capsulatum infection.
The hyperdense MCA sign and the MCA dot sign
Authors: Mahomed Nasreen
Published: May 2014

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Paediatric neuropathology
Authors: Misser S K , Roos J F
Published: May 2014

Quiz Case
RSSA MDCT Essentials Course 2011
Authors: Essentials Course RSSA MDCT
Published: May 2014

Abstracts
The South African Journal of Radiology goes GO RAD
Authors: Lots Jan
Published: May 2014

GO RAD