Introduction: The aim of this study is to (i) directly compare both two-dimensional (2D) and three-dimensional (3D) frontomaxillary facial angle (FMFA) in first trimester, and (ii) to assess the ease with which both may be performed. Materials and Methods: Both 3D volumes of the fetal head and 2D fetal profiles were collected from 251 consenting patients during routine first-trimester nuchal translucency (NT) screening. The FMFA in 2D was measured at the time of the NT screening. The 3D FMFA was measured offline. Results: The 2D FMFA was systematically higher than the 3D FMFA. The difference in 3D–2D FMFA was statistically significant from 11+0 to 12+3 weeks. From 12+4 to 13+6 weeks the difference was no longer significant with p = 0.06. Performing the measurement did not unduly increase the time of the study. Even for the experienced sonographer the technique is technically difficult, relying on many factors for accurate caliper placement. Discussion: The 2D FMFA is greater than the 3D angle. This was found in previous studies, but not thought to be statistically significant. The difference decreased with increasing gestational age. There is a learning curve associated with performing this measurement. Normative data for both 2D and 3D, incorporating ethnicity, may be necessary before inclusion in the first-trimester algorithm.
The purpose of this study was to investigate the cardiovascular and haemodynamic responses that occur during moderate orthostatic challenge in people with paraplegia, and the effect of electrical stimulation (ES)-induced leg muscle contractions on their responses to orthostatic challenge. Eight males with complete spinal lesions between the 5th and 12th thoracic vertebrae (PARA) and eight able-bodied individuals (AB) volunteered for this study. Changes in heart rate (fc), stroke volume (SV), cardiac output (Qc), mean arterial pressure (MAP), total peripheral resistance (TPR), limb volumes and indices of neural modulation of fc, [parasympathetic (PNS) and sympathetic (SNS) nervous system indicators] were assessed during: (1) supine rest (REST), (2) REST with lower-body negative pressure at -30 torr (LBNP -30, where 1 torr = 133.32 N/m2), and (3) for PARA only, LBNP -30 with ES-induced leg muscle contractions (LBNP + ES). LBNP -30 elicited a decrease in SV (by 23% and 22%), Qc (by 15% and 18%) and the PNS indicator, but an increase in fc (by 10% and 9%), TPR (by 23% and 17%) and calf volume (by 1.51% and 4.04%) in both PARA and AB subjects, respectively. The SNS indicator was increased in the AB group only. Compared to LBNP -30, LBNP + ES increased SV (by 20%) and Qc (by 16%), and decreased TPR (by 12%) in the PARA group. MAP was unchanged from REST during all trials, for both groups. The orthostatic challenge induced by LBNP -30 elicited similar cardiovascular adaptations in PARA and AB subjects. ES-induced muscle contractions during LBNP -30 augmented the cardiovascular responses exhibited by the PARA group, probably via reactivation of the skeletal muscle pump and improved venous return.
The role of deliberate practice (DP) theory in the development of expert performance has been widely studied. This paper reviews the concept of DP and the various factors that could impact the development or refining of essential sonography skills for students and practitioners. In this article, the authors review the concept of DP for its potential benefits and limitations in Medical Sonography education and its potential impact on the future calibre of practitioners. The paper encourages both novice and experienced practitioners to rethink how DP could enhance the notion of grasping a skill. Evidence from various areas of practice including the health professions has been used to argue that sonographers can successfully incorporate DP. This review opens up the opportunity for further conversations on how various skills could be isolated and improved using DP theory, with the primary aim of improving the quality of patient care in sonography practice.Funding: None. Conflict of interest: None.Sonography 5 76-81
In this study the cardiorespiratory responses during arm crank ergometry (ACE) performed at two submaximal intensities (30% and 50% of heart rate reserve) and moderate orthostatic challenge were investigated in individuals with paraplegia (PARA). The effect of concurrent electrical stimulation (ES)-induced leg muscle contractions on the responses to ACE during orthostatic challenge was also investigated. Eight PARA (T5-T12) and eight able-bodied (AB) individuals participated in this study, however only seven subjects from each group completed all tests and were used in subsequent data analyses. Oxygen uptake (VO2), heart rate (fc), stroke volume (SV) and cardiac output (Qc) were assessed during (1) ACE alone, (2) ACE and lower body negative pressure (ACE + LBNP), and, in PARA only, (3) ACE + LBNP with ES (ACE + LBNP+ ES). In both PARA and AB, ACE + LBNP decreased SV (by 13-18% and 20-23%, respectively) and increased fc (by 13-15% and 16%, respectively) compared to ACE alone. The decrease in SV was greater in AB than in PARA (significant group x trial interaction; both ACE intensities pooled), but there was no difference in the magnitude of increase in fc between groups. ES-induced leg muscle contractions increased SV (up to 16%) but did not change VO2 or Qc. The smaller reduction in SV from ACE to ACE + LBNP in PARA may indicate a mechanism by which adequate central blood volume can be maintained in the face of orthostatic challenge, despite the absence of supraspinal control below the spinal cord lesion. With ES-induced leg muscle contractions, the decrease in SV, which occurred during ACE + LBNP, was reversed via reactivation of the lower limb muscle pump and augmented venous return.
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