http://nova.newcastle.edu.au/vital/access/services/Feed ${session.getAttribute("locale")} 5 http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:11043 Resonant ultrasound spectroscopy has been used on single-crystal samples to observe pseudoproper ferroelastic softening across the (La,Pr)AlO₃ solid solution. It is suggested that softening is due to the presence of an intrinsic zone-center instability in addition to the small Jahn-Teller stabilization expected for Pr³⁺. Softening increases as smaller Pr³⁺ ions are substituted for larger La³⁺ which is attributed to a simple size effect as well as the possibility of bilinear coupling of the intrinsic instability with the weak Jahn-Teller effect. Superattenuation is observed above 600 K for all samples, which is consistent with twin wall related dissipation behavior seen in other perovskites with octahedral tilting. Superattenuation is also observed in the lowtemperature monoclinic phase, implying a high mobility also for the monoclinic twin walls. 2012-07-03T04:36:40.717Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:10404 Diagnostic ultrasound is traditionally and extensively used within the radiology department. However in recent years its use has expanded outside this traditional area into health professions such as physiotherapy, emergency medicine and anaesthesiology. The radiology community needs to be aware of the expansion of use of diagnostic ultrasound. This article starts this exploration in the health professions mentioned, however it is acknowledged that diagnostic ultrasound use goes beyond what is covered in this article. As diagnostic ultrasound is a user dependant modality and the outcome of an examination is largely influenced by the skill and experience of the operator, the radiology community should take a guiding role in its use, training and protocol development for health professionals. This article explores the literature on the use of diagnostic ultrasound within physiotherapy, emergency medicine and anaesthesiology. Literature was searched for on the databases Medline, Cinahl and Embase. Diagnostic ultrasound is being used in health professions such as physiotherapy, where it is being used to provide biofeedback to patients on contraction of abdominal and pelvic floor muscles; emergency medicine, for the investigation of free fluid within the abdomen of a trauma patient and anaesthesiology, for the placement of catheters and nerve blocks. As members of the radiology community are considered experts in the field, they need to take the lead to guide and mentor the other health professionals who are now using the modality. To be able to achieve this they must have an understanding of what these professions are using the modality for. 2012-03-14T03:20:05.014Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:9498 Uterine wall tension is thought to be an important determinant of the onset of labor in pregnant women. We characterize human uterine wall tension using ultrasound from the second trimester of pregnancy until parturition and compare preterm, term and twin pregnancies. A total of 320 pregnant women were followed from first antenatal visit to delivery during the period 2000–2004 at the John Hunter Hospital, NSW, Australia. The uterine wall thickness, length, anteriorposterior diameter and transverse diameter were determined by serial ultrasounds. Subjects were divided into three groups: women with singleton pregnancies and spontaneous labor onset, either preterm or term and women with twin pregnancies. Intrauterine pressure results from the literature were combined with our data to form trajectories for uterine wall thickness, volume and tension for each woman using the prolate ellipsoid method and the groups were compared at 20, 25 and 30 weeks gestation. Uterine wall tension followed an exponential curve, with results increasing throughout pregnancy with the site of maximum tension on the anterior wall. For those delivering preterm, uterine wall thickness was increased Pv0:05 compared with term. For twin pregnancies intrauterine volume was increased compared to singletons (Pv0:001), but wall thickness was not. There was no evidence for increased tension in those delivering preterm or those with twin gestations. These data are not consistent with a role for high uterine wall tension as a causal factor in preterm spontaneous labor in singleton or twin gestations. It seems likely that hormonal differences in multiple gestations are responsible for increased rates of preterm birth in this group rather than increased tension. 2012-01-30T05:11:57.525Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:9661 Background: The purpose of the study was the measurement of the anal cushion area using static transperineal ultrasound in a group of patients with symptomatic grade III and IV haemorrhoids about to undergo haemorrhoidectomy and compare them with a group of age-matched normals and the measured area following haemorrhoidectomy. Methods: Transperineal sonography was performed using a linear transducer measuring the anal cushion area by subtracting the measured luminal diameter of the undisturbed anal canal from the inner border of the internal anal sphincter. Measures were made 6 weeks following haemorrhoidectomy. Results: Comparisons were made between 22 normals and 36 patients with haemorrhoids (31 evaluable post-operatively). The median area of normals was 0.78 cm², that of pre-operative patients 2.25 cm² and that of post-operative cases 1.20 cm². There was a significant difference between pre- and post-operative cases with cushion areas of normal patients being significantly lower than post-operative cases. Variance of measurement in all 3 groups was negligible. Conclusion: Static transperineal sonography measuring the anal cushion area is reproducible and shows marked differences between normals and patients with symptomatic haemorrhoids. There is a marked effect on measured area resultant from haemorrhoidectomy. 2011-12-08T01:30:03.785Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:9419 Background: Chronic anal pain is relatively common as a presentation to specialist physicians and surgeons. Currently, it is regarded as a functional disorder upon the exclusion of occult intersphincteric sepsis. Our study assessed an unselected cohort of patients presenting with chronic previously undiagnosed anal pain using routine ultrasonography. Methods: All patients referred to a tertiary gastroenterology service between January 2005 and January 2008 with a diagnosis of chronic anal pain (>3 months duration with no clinical anorectal signs) underwent endoanal and static and dynamic transperineal ultrasound to assess for the frequency and pattern of occult intersphincteric sepsis. Results : Of 1,580 patients referred, there were 146 presenting with chronic anal pain as a main symptom. Of these, 37 (25.3%) had intersphincteric sepsis (ISS) diagnosed with ultrasound examination with 17 undergoing evaluable surgery. There was a male preponderance (70.3%) with the diagnosis being made in 46% of cases after 6 months of symptoms and with 80.8% having posteriorly located sepsis. This occurred on a background of 62% having previous acute proctological conditions. There was complete ultrasonographic and operative concordance with 15 becoming asymptomatic after surgery at a mean follow-up of 6 months. Conclusion : Occult intersphincteric sepsis is not uncommon and is diagnosed using routine ultrasonography at the time of clinical presentation. Endoanal and transperineal ultrasound is recommended as part of the investigative armamentarium to exclude categorization as functional anorectal pain. This is currently not part of the Rome III coding for such a diagnosis suggesting a revision of these diagnostic criteria for the ultimate diagnosis of functional proctalgia. 2011-11-17T04:10:03.726Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:7709 Elastic behaviour associated with the hierarchy of tilting transitions in SrZrO₃ has been examined using resonant ultrasound spectroscopy on a ceramic sample at temperatures between 153 and 1531 K. Changes in slope of the evolution of resonance frequencies with temperature indicate that phase transitions occur at 1038 K (Pnma ↔ Imma), 1122 K (Imma ↔ I4/mcm), and 1367 K (I4/mcm ↔ Pm3m). Strain analysis of previously recorded neutron diffraction data shows that the I4/mcm ↔ Pm3m and Pnma ↔ Imma transitions are close to tricritical in character, and that Imma ↔ I4/mcm is first order. Deviations from the form of the elastic behaviour predicted by Landau theory are found. In particular, elastic softening in the vicinity of the Imma ↔ I4/mcm transition suggests that local dynamical fluctuations between individual tilt systems occur, rather than a discontinuous switch from one phase to another. Determinations of the mechanical quality factor, Q, show that SrZrO₃ in the Pm3m phase is a classically high-Q (i.e. non-dissipating) cubic material. I4/mcm and Imma phases both have much greater dissipation (low Q), which is tentatively attributed to the mobility of twin walls. The room temperature Pnma phase is unexpectedly much stiffer than both I4/mcm and Imma phases and has high Q. It appears that when two separate tilt systems operate, as in Pnma, they can interact to reduce strain/order parameter relaxations. 2011-09-13T00:41:06.701Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:7479 Aims: The aims of this study were to develop and evaluate a shorter gestational age estimation method based on the Dubowitz scoring system (DSS) that could be taught easily to untrained health-care workers. Methods: Using the DSS, seven criteria were identified that explained 90% of the variance in gestational age estimation. Ventral suspension was excluded, skin texture was substituted for skin colour and ear bending was for ear firmness. The final six criteria comprise the short DSS (SDSS). The study population was 100 babies, 51 Caucasian, 34 Aboriginal. Birth weight ranged from 1351 to 5430 g. The gestational age range was 29.6–41.7 weeks. Three researchers (medical student 1 (MS1), medical student 2 (MS2) and a paediatrician) who were blind to other available gestational age estimations assessed babies within 72 h of birth using the DSS and SDSS. Results: MS1 found the 95% limits of agreement (LOA) between SDSS and DSS to be −1.1 to 1.7 weeks. In the 27 babies who had first trimester foetal ultrasound (USS), the LOA between USS and SDSS were −1.9 to 1.4 weeks and −2.3 to 1.9 weeks, respectively. Using the SDSS, the LOA for the three researchers were within ±2 weeks. Conclusion: The data presented suggest that the SDSS is approximately equivalent to the DSS in the relatively limited population studied, and within these limitations appears to be a simple alternative to the DSS. Further evaluation is needed before firm conclusions about the accuracy and clinical utility of the SDSS can be made. 2011-03-25T05:30:09.211Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:1913 The practice of obstetric ultrasound scans has undergone significant expansion in the last two decades and is now a standard part of many women's antenatal care in Australia as elsewhere. This article reviews recent evidence about the value of obstetric ultrasound, summarizing debates and contradictions in research literature and practitioner guidelines. Pregnant women's interpretations of the significance of ultrasound are examined through multiple interviews with 34 study participants. We find that ultrasound has become an integral part of women's embodied experience of pregnancy, with its own pleasures and dilemmas. The increasing use the technology has augmented the role of scientific biomedicine in the government of pregnancy. This must be understood in the light of trends toward individualized risk management in which the pregnant woman increasingly takes responsibility for the successful outcome of the pregnancy, in a context where pregnancy is discursively constructed as a risky domain of gendered experience in contemporary Australian society. 2010-04-27T06:57:48.372Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:499 Objective: To compare the effects of deep heating (short-wave diathermy [SWD]) and superficial heating (hydrocollator packs) on tissue extensibility. Design: A double-blind, repeated-measures study. Possible effects of sex and intervention order were controlled. Setting: A clinical laboratory. Participants: Twenty-four subjects with no neurologic or musculoskeletal pathologies affecting their lower limbs. Interventions: Three intervention conditions: deep heating (SWD), superficial heating (hot packs), and no heating were applied in preallocated order to each subject at least 36 hours apart. Main Outcome Measures: Ankle dorsiflexion in weight bearing Was measured by using an inclinometer to ascertain changes in the extensibility of the calf muscles and associated soft tissues. Results: Deep heating increased the range of ankle dorsiflexion by 1.8 degrees +/- 1.9 degrees. The change in ankle dorsiflexion after superficial and no heating was 0.7 degrees +/- 1.5 degrees and -0.1 degrees +/- 1.0 degrees, respectively. Conclusions: Deep heating, in the absence of stretching, increases tissue extensibility more than superficial heating or no heating. Superficial heating is more effective than no heating. but the difference was not statistically significant. 2010-04-27T05:40:51.198Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:4421 Review of: Whittacker JL (2007) Ultrasound imaging for rehabilitation of the lumbopelvic region. Philadelphia: Elsevier Churchill Livingstone,183 pages. ISBN 0 443 06856 9. 2010-04-27T04:54:21.679Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:5679 I would like to thank Dr. Kerry and Mr. Taylor for raising some important issues related to cervical spine pre-manipulative screening in response to my recent editorial (Rivett, 2006).Of course, an editorial is by nature brief and cannot fully cover all matters pertaining to this issue. It is also by definition an opinion or view, albeit an informed one. 2010-04-27T04:49:53.585Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:5686 The authors comment in response to three letters to the editor regarding their article: Thomas LC, et al. Premanipulative testing and the velocimeter. Manual Therapy (2007) - available from [http://dx.doi.org/10.1016/j.math.2006.11.003]. 2010-04-27T04:44:00.483Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:5818 The currently advocated pre-manipulative risk assessment protocols include the use of provocative positional tests to challenge the integrity of the vascular supply to the brain. This paper examines the validity of these pre-manipulative provocative tests in light of recent studies involving ultrasound scanning of the vertebral arteries in subjects who also had provocative tests performed. These studies indicate that the provocative positional tests may produce both false positive and false negative findings. Recent research concerning the use of a continuous wave Doppler velocimeter suggests this device may provide a more objective assessment of vertebral artery blood flow than the present provocative tests. However, the sensitivity and specificity of the use of the velocimeter in identifying altered or abnormal vascular flow in the vertebral arteries, and therefore its clinical utility, remain to be fully established. 2010-04-27T04:37:02.713Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:5266 Our knowledge of uses of low-frequency ultrasound is still developing. However, convincing studies are required—methodologically adequate studies that probe the effectiveness of 40-kHz frequency ultrasound for wound healing and compare its relative contribution to that of the means of delivering the irrigating fluid. 2010-04-27T04:32:55.908Z ]]>