ESTeSL - Escola Superior de Tecnologia da Saúde de Lisboa
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Browsing ESTeSL - Escola Superior de Tecnologia da Saúde de Lisboa by Author "Aandahl, Ingrid J."
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- An analysis of the validity and reliability of a handheld ultrasound device for measuring rectus femoris muscle sizePublication . Nijholt, Willemke; Bakker, Astrid; Bennett, Alicia C.; Borgen, Morten H.; Ellermann, Anne; Hogg, Peter; Gamboa, Patrícia T.; Thorskog, Martine; Vorster, Liesl; Aandahl, Ingrid J.Background: Previous studies show that ultrasound is valid and reliable when measuring muscle size. A Philips handheld ultrasound device was released in April 2015. The aim of this study was to investigate the validity and reliability of the handheld ultrasound device compared to a conventional ultrasound device, when measuring the size of the rectus femoris (RF). Methods: Two sonographers scanned 39 volunteers (mean age=29.3y, 26 female), once with the Toshiba SSA-660A (regular) ultrasound device and twice with the Philips hand held VISIQ device. The size of the RF (expressed in cross sectional area (CSA) was measured two ways; using the trackball on the Toshiba device and an automatic region of interest on the VISIQ device (method 1), and an ellipse on both devices using the formula π*half width*half length (method 2). Results: Method 1 resulted in an intraclass correlation coefficient (ICC) of .811 with a 95% (confidence interval) CI of .773-.837 (inter-rater reliability) and .907 with a 95% CI of .822-.951 (validity). The ICCs of method 2 were .787 with a 95% CI of .593-.888 (inter-rater reliability) and .867 with a 95 % CI of .746-.930 (validity). Conclusion: VISIQ is a valid and reliable device for measuring RF-CSA. In clinical practice VISIQ could be used for measuring RF-CSA, consequently it could be an economical and easily portable technology for use in both clinical and residential settings.
- Radiography: impact of lower tube voltages on image quality and radiation dose in chest phantom radiography for averaged sized and larger patientsPublication . Hauge, I. H.; Aandahl, Ingrid J.; Baranzelli, J. P.; Coelho, P. M.; Eriksen, L. M.; Hadebe, N. S.; Kahl, G. G.; van Schagenf, S. J.; O’Connor, M.Background: A tube voltage of 120 kVp is the standard in chest radiography. However, three studies have found that a lower kVp (e.g. 80 kVp) may provide better image quality for visualizing lung tissue and the cardiac silhouette. The aim of this study is to investigate the impact of tube voltage reduction on dose and image quality of DR chest phantom radiographs. Method: An anthropomorphic chest phantom, without and with additional chest plates, to simulate a normal and large male chest torso body type, was imaged in posterior-anterior (PA) and lateral projections using stepwise increases of 10 kVp, from 60 to 130 kVp. Subjective image analysis was conducted by doing visual grading analysis (VGA). Six observers rated the image quality score (IQS). In addition, the contrast-to noise ratio for nine regions was obtained. In order to optimize with regards to both image quality and dose, the figure of merit (FOM) (=Contrast-to-Noise-Ratio squared/DAP),was estimated at each selected kVp. Results: Visual grading analysis showed that the best IQS can be obtained at a lower tube voltage than 120 kVp, but only for PA projection when imaging larger persons, does a lower kVp (100 kVp) provide a better FOM than 120 kVp, and this only occurs when imaging the vertebrae, trachea and left ventricle Conclusion: The VGA analysis showed that it is possible to reduce the kVp, and still get good image quality. However, more extensive VGA is needed in order to come to a definite conclusion.
- Ultrasound assessment of muscle thickness and muscle crosssectional area: a reliability studyPublication . Nijholt, W.; Aandahl, Ingrid J.; Adajar, G.; Borgen, M. H.; Carreiras, I.; Rab, A.; Totland, H.; Warmerdam, N. C.; van der Wal, S. C. M.; Crofts, G.Purpose: Previous studies showed that ultrasound imaging is reliable when measuring the cross-sectional area (CSA) of a muscle. However, measurements of muscles could be affected by the level of experience of the observer. The aim of this pilot study was to investigate the reliability of observers when measuring the CSA and thickness of the rectus femoris (RF). Methods and Materials: Seven observers assessed eight different images of RF. On each image, the CSA and thickness were measured three times using ImageJ. The measurements were analyzed using IBM SPSS. Intraclass Correlation Coefficient (ICC) and Bland-Altman plots were used to analyze reliability. A Paired Sample T-Test was used to investigate any differences between the first and mean measurement recorded by the observers. Results: No significant differences were found between the first and mean of the repeated measures for CSA and thickness respectively (p = 0.217-0.817, p = 0.337-0.897). Intra-observer reliability shows excellent agreement between measurement one and the mean for each observer (CSA ICC = 0.987-1.000, thickness ICC = 0.996-1.000). High inter-observer reliability was found for both CSA (ICC = 0.938, 95% CI = 0.845-0.985) and thickness (ICC = 0.9774, 95% CI = 0.934-0.994). Agreement between an experienced and inexperienced observer was excellent (ICC = 0.991, 95% CI = 0.959-0.998). Conclusion: This pilot study shows that there is a high level of inter- and intraobserver reliability among the observers in measuring the CSA and thickness of the RF. It also shows that experience in ultrasound measurements is not a factor in reliability.