ESC core curriculum for the general cardiologist (2013)

[No abstract available

Role of Computational Fluid Dynamics in the Analysis of Haemodynamic and Morphological Characteristics of Intracranial Aneurysms

Aneurysmal subarachnoid hemorrhage (SAH) carries a high morbidity and mortality. The current protocols used to treat the unruptured Intracranial Aneurysms (IAs) are inadequate underscoring the need of finding new descriptors. As demonstrated by the studies performed in this manuscript, haemodynamics plays an important role in the aetiopathogenesis of IAs. An evaluation of haemodynamic indices can provide a useful alternative to predict the behavior of an unruptured IA at an early stage. Studies performed by me demonstrate that Computational Fluid Dynamics (CFD) can be used successfully to predict haemodynamic indices where detailed in vivo measurement of haemodynamic flow variables is not possible owing to technical limitations. European Commission funded Project @neurIST was the first project of it’s kind that brought together a number of multidisciplinary professionals from 32 European institutions and made possible development of state-of-the-art tools for personalised risk assessment and treatment IAs using CFD. These tools have been constantly improved and amended in the light of feedback gathered from their controlled exposures conducted world over, as described in the manuscript. However, need of a well-designed Randomized Controlled Trial in this context cannot be overemphasized, before these tools can be accepted by clinicians and patients. In my study on the validation of different concepts used in CFD, I demonstrated that there is no added advantage of complex Womersley-flow-profile over the much simpler plug-flow profile. One of my studies on initiation and rupture of IAs showed that the haemodynamic patterns of IAs during these two phases are significantly different with values of supra-physiological Wall Shear Stress (WSS) being higher in initiation while lower in rupture phase. I also investigated the effects of pharmacological agents on the aetiopathogenesis of IAs and found that heparin induces significant derangements in the haemodynamics of both, pre-aneurysmal as well as ruptured IA. I propose that heparin (and its derivatives) can, on the one hand may facilitate the rupture of existing IAs, on the other hand they may suppress the formation of new IAs. I have also found significant differences in the results using patient-specific vs. Modeled Boundary Conditions and showed that the 1D circulation model adopted by @neurIST performs better than other approaches found in the literature. I also proposed a novel mechanism of increase in Blood Viscosity leading to high WSS as one of the important underlying mechanisms responsible for the increased incidence of IA formation in smokers and hypertensive patients. In my study on patients with pre-existing Coarctation of Aorta (CoA) and Intracranial Aneurysms, I demonstrated that the cerebral flow-rates in CoA patients were significantly higher when compared to average flow-rates in healthy population. It was also seen that the values and the area affected by supraphysiological WSS (>15Pa) were exponentially higher in patients with CoA indicating the possible role of increased haemodynamic WSS secondary to the increased flow-rates playing an important role in the pathogenesis and rupture of IAs in CoA patients

A Journey Through The Thoracic Aorta: From Root To Arch

This thesis investigated the clinical and pathological outcomes of disease of the aortic valve and the ascending aorta, including the aortic root. Purpose: The aortic valve and proximal aorta are the anatomical origin of the systemic circulation and pathology in this area can be catastrophic. Despite this, there is limited knowledge of the pathophysiology of proximal aortic aneurysms and patient outcomes for treatment strategies of aortic valve disease. The purpose of this thesis is to strengthen the knowledge of pathology affecting the thoracic aorta so that it can help guide clinical management in the future. Aims: This thesis aims to investigate the effects of pathology on the aortic valve and thoracic ascending aorta through determination of: 1. The pathophysiology of proximal aortic aneurysms, specifically focusing on evaluating aortic root and ascending aortic aneurysm in relation to (a) histology (Chapter 2) and (b) propensity to aortic rupture in pigs in-vitro (Chapter 3) and in-vivo (Chapter 4) models; and 2. Comparing SAVR & TAVR in relation to (a) clinical outcomes (Chapter 5) and (b) patient-related outcomes (Chapter 6). Methods: Chapter 2, focused on histological analysis of aneurysmal aortas, and involved laboratory preparation of human aneurysmal and non-aneurysmal tissue and analysis utilizing histological and immunohistochemistry techniques. Chapter 3, which focused on a laboratory pig model in ascending aorta and aortic root rupture, involved laboratory preparation of pig non-aneurysmal samples, and utilised a unique pressure testing apparatus, to determine the maximal stress the root and ascending aorta can withstand prior to rupture. This was a pilot study for Chapter 4. Chapter 4, which focused on a live pig model in ascending aorta and aortic root rupture, involved placement of live pigs on cardiopulmonary bypass, and determination of maximal aortic pressures prior to rupture or failure of the aorta clinically and radiologically using 4D flow MRI. This ruptured tissue was then analysed utilising histological and immunohistochemistry techniques. Chapter 5 which focused on clinical outcomes of aortic valve surgery, utilised the ANZSCTS national database from Monash Health, incorporating data collection and analysis from 2001 to 2019. Chapter 6 which focused on the patient-related outcomes following aortic valve surgery, involved the use of validated questionnaires of patients over a 12-month period following their surgery. Specific outcomes measured included frailty, depression, angina, and quality of life. Results and Discussion: Chapter 2, 3, and 4 focus on the comparisons in structure between two anatomical regions of the aorta, while Chapter 5 and 6 focus on comparisons in approach between two methods of aortic valve replacement. All Chapters give us valuable knowledge as to how we can manage aortic pathology not only during surgery, but also during the patient’s perioperative journey. The aortic root is the most susceptible region of the thoracic aorta and is predisposed to progression of pathology and rupture in clinical testing. The aortic root is more vulnerable to high pressures, further exacerbated by aneurysmal changes, supported by both microscopic and macroscopic characteristics, while the ascending aorta retains its resilience in comparison. This identified a difference between the aortic root and ascending aorta not only in known anatomical and physiological form, but in each areas ability to maintain its integrity in severe stress and aneurysmal pathological change. With respect to outcomes post aortic valve replacement, the ANZSCTS database showed no difference in composite endpoints of mortality and stroke between Surgical aortic valve replacement (SAVR) and Transcatheter aortic valve replacement (TAVR), while the degree of morbidity (complete heart block requiring pacemaker and vascular complications) was more prevalent in TAVR groups. In contrast, quality of life, depression, angina, and frailty consecutively measured over 12 months, showed significant improvement in both SAVR and TAVR groups, and an obvious benefit to these measures in all patients requiring intervention for aortic stenosis. When these two groups (SAVR and TAVR) were matched, clinically relevant preoperative variables were identified as being predictive of early mortality. Conclusions: The aortic root differs to the ascending aorta under maximal stress and in response to pathological change. Following further clinical testing and human trials, consideration should be for surgical management of these structures as separate entities. Transcatheter approaches are evolving with improved outcomes in large scale randomised trials supported by our findings of composite primary end points, as well as comparable improvement in quality of life, angina, depression, and frailty with surgical groups. Clinically significant morbidity in the form of vascular and electrophysiological complications remain high, and this should be a focus of ongoing long term clinical trials before an absolute incorporation of this technique for all patients with aortic stenosis. Recommendations: This unique analysis offers a new perspective of root and ascending aorta dilatation with strong clinical implications. These two structures deserve new and different management. National databases reporting on outcomes in aortic valve surgery should consider combining databases regardless of transcatheter or open surgical approach, to allow for a comprehensive and accurate representation of morbidity and mortality outcomes. Longer term analysis of these morbidity results should guide clinical guidelines as to the appropriate use of these techniques in aortic valve disease, and the utilisation of combined surgical and physician teams in performing these procedures.Thesis (Ph.D.) -- University of Adelaide, Adelaide Medical School, 202

Aerospace Medicine and biology: A continuing bibliography with indexes, supplement 123, January 1974

This special bibliography lists 226 reports, articles, and other documents introduced into the NASA scientific and technical information system in Dec. 1973

Physical science techniques for non-invasive, quantitative measurements within the living human body

The research in this thesis focuses on the use of a range of physical science techniques to perform quantitative measurements within the living human body in a non-invasive manner, for the purpose of understanding disease processes, diagnosing abnormality or monitoring therapeutic responses. The research publications cover work which has been undertaken over the last thirty years in the Universities of Edinburgh, London and Leeds. The research has not concentrated on one aspect of the physical sciences but has taken advantage of scientific and technological developments, encompassing neutron, X and y ionising radiation, laser and THz non-ionising radiation, magnetism, radio-waves and a range of mathematical and computing techniques. Clinical applications have encompassed a wide range of diseases and conditions and include osteoporosis and other metabolic bone diseases, cardiac disease, vascular disease, rheumatoid arthritis and cancer.PUBLICATIONS • • BONE MEASUREMENT • 1. Development of apparatus to measure calcium changes in the forearm and spine by neutron activation analysis using Cf-252 (*PhD) MA Smith and P Tothill Physics in Medicine and Biology 24, 319-329, 1979 2. Measurement of spinal calcium by in vivo neutron activation analysis in osteoporosis (*PhD) MA Smith, R Eastell, NSJ Kennedy, LG Mcintosh, JD Simpson, JA Strong and P Tothill Clinical Physics and Physiological Measurement 2, 45-48, 1981 3. Long term effect of dialysate calcuim and 1a -OHD3 on bone calcium in haemodialysis patients as measured by neutron activation analysis of the forearm (*PhD) MA Smith, RJ Winney, JA Strong and P Tothill Nephron 28, 213-217, 1981 4. Total body neutron activation analysis of calcium: calibration and normalisation NSJ Kennedy, R Eastell, CM Ferrington, JD Simpson, MA Smith, JA Strong and P Tothill Physics in Medicine and Biology 27, 697-708, 1982 5. The crossover correction in dual photon absorptiometry with Gd-153 MA Smith and P Tothill Physics in Medicine and Biology 27, 1515-1521, 1982 6. Bone demineralisation in patients with Turner's syndrome MA Smith, J Wilson and WH Price Journal of Medical Genetics 19, 100-103, 1982 7. Total body calcium in rheumatoid arthritis: effects of disease activity and corticosteroid treatment DM Reid, NSJ Kennedy, MA Smith, P Tothill and G Nuki British Medical Journal 285, 330-332 1982 8. Comparison between Gd-153 and Am-241, Cs-137 for dual photon absorptiometry of the spine MA Smith, D Sutton and P Tothill Physics in Medicine and Biology 28, 709-721, 1983 9. Intra-laboratory variations using dual photon absorptiometry MA Smith and P Tothill Physics in Medicine and Biology 28, 748-751, 1983 10. Dual photon absorptiometry of the spine with a low activity source of gadolinium 153 P Tothill, MA Smith and D Sutton British Journal of Radiology 56, 829-835, 1983 11. Normal levels of total body sodium and chlorine by neutron activation analysis NSJ Kennedy, R Eastell, P Tothill and MA Smith Physics in Medicine and Biology 28, 215-222, 1983 12. The assessment of postmenopausal osteoporosis by total body neutron activation analysis R Eastell, NSJ Kennedy, MA Smith, JD Simpson, JA Strong and P Tothill Metabolic Bone Disease and Related Research 5, 65-67, 1983 13. Bone mass in nodal primary generalised osteoarthritis DM Reid, NSJ Kennedy, MA Smith, P Tothill and G Nuki Annals of the Rheumatic Diseases 43, 240-242, 1984 14. Changes in total body calcium after renal transplantation effect of low-dose steroid regime R Eastell, NSJ Kennedy, MA Smith, P Tothill and JL Anderton Nephron 40, 139-142, 1985 15. The seasonal variation of total body calcium P Tothill, NSJ Kennedy, JJ Nicoll, MA Smith, DM Reid and G Nuki Clinical Physics and Physiological Measurement 7, 361-367, 1986 16. Bone mass in ankylosing spondylitis DM Reid, JJ Nicoll, NSJ Kennedy, MA Smith, P Tothill and G Nuki Journal of Rheumatology 13, 932-935, 1986 17. Corticosteroids and bone mass in asthma: comparisons with rheumatoid arthritis and polymyalgia rheumatica DM Reid, JJ Nicoll, MA Smith, B Higgins, P Tothill and G Nuki British Medical Journal 293, 1463-1466, 1986 18. Total and peripheral bone mass in patients with psoriatic arthritis and rheumatoid arthritis DM Reid, NSJ Kennedy, JJ Nicoll, MA Smith, P Tothill and G Nuki Clinical Rheumatology 5, No 3, 372-278, 1986 19. Changes in total body calcium following surgery for primary hyperparathyroidism R Eastell, NSJ Kennedy, MA Smith, P Tothill and CRW Edwards Bone 7, 269-272 1986 20. Bone loss in rheumatoid arthritis and primary generalized osteoarthrosis: effects of corticosteroids, suppressive antirheumatic drugs drugs and calcium supplements DM Reid, NSJ Kennedy, MA Smith, JJ Nicoll, N Brown, P Tothill and G Nuki British Journal of Rheumatology 25, 253-259, 1986 21. Measurement of hand bone mineral content using single-photon absorptiometry JJ Nicoll, MA Smith, DM Reid, E Law, N Brown, P Tothill and G Nuki Physics in Medicine and Biology 32, 697-706, 1987 22. In-vivo precision of total body calcium and sodium measurements by neutron activation analysis JJ Nicoll, P Tothill, MA Smith, DM Reid, NSJ Kennedy and G Nuki Physics in Medicine and Biology 32, 243-246, 1987 23. Prediction of fracture healing in the tibia by quantitative radionuclide imaging MA Smith, E Jones, R Strachan, P Tothill, JJK Best and SPF Hughes Journal of Bone and Joint Surgery 69-B, 441-448, 1987 24. Premenopausal bone loss in the lumbar spine and neck of femur: a study of 225 Caucasian women A Rodin, B Murby, MA Smith, M Caleffi, I Fentiman, MG Chapman and I Fogelman Bone 11, 1-5, 1990 25. Bone ultrasound attenuation in women: reproducibility, normal variation and comparison woth photon absorptiometry JG Truscott, M Simpson, SP Stewart, R Milner, CF Westmacott, B Oldroyd, JA Evans, A Horsman, CM Langton and MA Smith Clinical Physics and Physiological Measurement 13, 29-36, 1992 26. The use of a radiation sensitive CCD camera system to measure bone mineral content in the neonatal forearm: a feasibility study JG Truscott, R Milner, S Metcalfe and MA Smith Physics in Medicine and Biology 37, 1391-1397, 1992 27. Primary Generalised Osteoarthritis and Bone Mass LD Hordon, SP Stewart, PR Troughton, V Wright, A Horsman and MA Smith British Journal of Rheumatology 32, 1059-1061, 1993 28. Variation in lumbar spine and femoral neck bone mineral measured by dual energy X-ray absorption: a study of 329 normal women JG Truscott, B Oldroyd, M Simpson, SP Stewart, CF Westmacott, R Milner, A Horsman and MA Smith British Journal of Radiology 66, 514-521, 1993 29. A phantom for quantitative ultrasound of trabecular bone AJ Clarke, JA Evans, JG Truscott, R Milner and MA Smith Physics in Medicine and Biology 39, 1677-1687, 1994 30. Comparison of changes in bone mineral in idiopathic and secondary osteoporosis following therapy with cyclical disodium etidronate and high dose calcium supplementation SM Orme, M Simpson, SP Stewart, B Oldroyd, CF Westmacott, MA Smith and PE Belchetz Clinical Endocrinology 41(2), 245-50, 1994 31. A portable system for measuring bone mineral density in the pre-term neonatal forearm JG Truscott, R Milner, PC Holland, C Wood and MA Smith British Journal of Radiology 69, 532-8, 1996 32. Assessment of renal osteodystrophy in dialysis patients: use of bone alkaline phosphatase, bone mineral density and parathyroid ultrasound in comparison with bone histology S Fletcher, RG Jones, HC Rayner, P Harnden, LD Hordon, JE Aaron, B Oldroyd, AM Brownjohn, JH Turney and MA Smith Nephron 75(4), 412-9, 1997 33. Regional bone mineral density after orthotopic liver transplantation SH Hussaini, B Oldroyd, SP Stewart, F Roman, MA Smith, S Pollard, P Lodge, JG O'Grady and MS Losowsky European Journal of Gastroenterology Hepatology 11(2), 157-63, 1999 • PATENTS (COPIES NOT INCLUDED) • 34. Material to mimic bone and its interaction with ultrasound J Clarke, JA Evans, R Milner and MA Smith 1994 35. Anthropomorphic spinal phantom R Milner, E Berry and MA Smith 1999 • STATISTICS • 36. The comparison of neutron activation analysis and photon absorptiometry at the same part body site MA Smith, RA Elton and P Tothill Clinical Physics and Physiological Measurement 2, 1-7, 1981 37. Survival after peptic ulcer surgery AH McLean Ross, J Anderson, WP Small and MA Smith British Medical Journal 282, 1472, 1981 38. Late mortality after surgery for peptic ulcer AH McLean Ross, MA Smith, JR Anderson and WP Small New England Journal of Medicine 307, 519-522, 1982 39. Survival after surgery WP Small, MA Smith and AH MacLean-Ross British Medical Journal 289, 108-109, 1984 40. Metabolism of sodium pentosan polysulphate in man-catabolism of iodinated derivatives IR MacGregor, J Davies, L Paton, DS Pepper, CV Prowse and MA Smith Thrombosis and Haemostasis 51, 321-325, 1984 41. Correction factors for gravimetric measurement of peritumoural oedema in man BA Bell, MA Smith, JL Tocher and JD Miller British Journal of Neurosurgery 1, 435-440, 1987 42. Inter-individual differences in the pituitary-thyroid axis influence the interpretation of thyroid function tests CA Meier, MN Maisey, A Lowry, J Muller and MA Smith Clinical Endocrinology 39, 101-107, 1993 • MAGNETIC RESONANCE IMAGING • 43. The installation of a commercial resistive NMR imager MA Smith, JJK Best, RHB Douglas and DM Kean British Journal of Radiology 57, 1145-1158, 1984 44. Brain water in chronic alcoholic patients measured by magnetic resonance imaging MA Smith, J Chick, DM Kean, RHB Douglas, A Singer, RE Kendell and JJK Best Lancet i, 1273-1274, 1985 45. Nuclear magnetic resonance imaging in hypertrophic cardiomyopathy M Been, DM Kean, MA Smith, RHB Douglas, JJK Best, and AL Muir British Heart Journal 54, 48-52, 1985 46. Two examples of CNS lipomas demonstrated by CT and low field MRI DM Kean, MA Smith, RHB Douglas, CN Martyn and JJK Best Journal of Computer Assisted Tomography 9(3), 494-496, 1985 47. Characterisation of acute myocardial infarction by gated magnetic resonance imaging M Been, MA Smith, JP Ridgway, JWE Brydon, RHB Douglas, DM Kean, JJK Best and AL Muir Lancet ii, 348-350, 1985 48. Brain water measured in volunteers after alcohol and vasopressin AJ Mander, MA Smith, DM Kean, J Chick, RHB Douglas, AU Rehman, GJ Weppner and JJK Best Lancet, ii, 1075, 1985 49. ECG gated T1 images of the heart MA Smith, JP Ridgway, JWE Brydon, M Been, RHB Douglas, DM Kean, JJK Best and AL Muir Physics in Medicine and Biology 31, 771-778, 1986 50. The absence of tissue specificity in MRI using in-vivo T1 or T2 determination - true biological variation or technical artefact? MA Smith and DG Taylor British Journal of Radiology 59, 82-83, 1986 51. A description of a low field resistive magnetic resonance imaging system and its application in imaging midline central nervous system pathology DM Kean, MA Smith, RHB Douglas and JJK Best Clinical Radiology, 37, 211-217, 1986 52. A technique for velocity imaging using magnetic resonance imaging JP Ridgway and MA Smith British Journal of Radiology 59, 603-607, 1986 53. Correlation of human NMR T1 values measured in vivo and brain water content HL MacDonald, BA Bell, MA Smith, DM Kean, JL Tocher, RHB Douglas, JD Miller and JJK Best British Journal of Radiology 59, 355-357, 1986 54. A surface coil design for a vertical field MRI system and its application in imaging the breast MA Smith and DW Pye Magnetic Resonance Imaging 4, 455-560 1986 55. Cardiac gating in nuclear magnetic resonance imaging MA Smith Journal of Medical Engineering and Technology 10(6), 325-328, 1986 56. Brain water measured by magnetic resonance imaging: correlation with direct estimation and changes after mannitol and dexamethasone BA Bell, MA Smith, DM Kean, CNJ McGhee, HL MacDonald, JD Miller, GH Barnett, JL Tocher, RHB Douglas, JJK Best The Lancet (i), 66-69, 1987 57. Demonstration of pulsatile cerebrospinal-fluid using magnetic resonance phase imaging JP Ridgway, LW Turnbull and MA Smith British Journal of Radiology 60, 423-427, 1987 58. Magnetic resonance flow imaging: a possible method for distinguishing communicating syringomyelia from cystic intraspinal lesions LW Turnbull, JP Ridgway, MA Smith and JJK Best British Journal of Radiology 60, 517-518, 1987 59. Cerebral and brain stem changes after ECT revealed by nuclear magnetic resonance imaging AJ Mander, A Whitfield, DM Kean, MA Smith, RHB Douglas and RE Kendell British Journal of Psychiatry 151, 69-71, 1987 60. Serial changes in the T1 magnetic relaxation parameter after myocardial infarction in man M Been, MA Smith, JP Ridgway, RHB Douglas, DP De Bono, JJK Best and AL Muir British Heart Journal 59, 1-8, 1988 61. Myocardial involvement in systemic lupus erythematosus detected by magnetic resonance imaging M Been, BJ Thompson, MA Smith, JP Ridgway, RHB Douglas, JJK Best and AL Muir European Heart Journal 9 1250-1256, 1988 62. Brain hydration during alcohol withdrawal in alcoholics measured by magnetic resonance imaging MA Smith, JD Chick, HM Engelman, DM Kean, AJ Mander, RHB Douglas and JJK Best Drug and Alcohol Dependence 21, 25, 1988 63. Magnetic resonance spectroscopy in-vivo DA Porter, MA Smith Journal of Biomedical Engineering 10, 562-567, 1988 64. Blood flow imaging by magnetic resonance DJ West, M Tarnawski, MJ Graves, MG Taylor, S Padayachee, VT Ayton and MA Smith Medicamundi 33, 101-111, 1988 65. Magnetic resonance imaging of the infant heart at 15T MA Smith, EJ Baker, VT Ayton, JM Parsons, EJ Ladusans and MN Maisey British Journal of Radiology 62, 367-370, 1989 66. High field strength magnetic resonance imaging of ventricular septal defects in infants EJ Baker, VT Ayton, MA Smith, JM Parsons, EJ Ladusans, RH Anderson, M Tynan and NLK Fagg British Heart Journal 62, 305-310, 1989 67. Magnetic resonance imaging of coarctation of the aorta in infants: use of high field strength EJ Baker, VT Ayton, MA Smith, JM Parsons, EJ Ladusans, RH Anderson, M Tynan, AK Yates and PB Deverall British Heart Journal 62, 97-101, 1989 68. Magnetic resonance imaging of the brain in alcoholics: cerebral atrophy, lifetime alcohol consumption and cognitive defects JD Chick, MA Smith, HM Engleman, DM Kean, AJ Mander, RHB Douglas and JJK Best Alcoholism: Clinical and Experimental Research 13, 512-517, 1989 69. Phospholipids are visible in P-31 NMR spectra of human breast tumours M Lowry, DA Porter, CJJ Twelves, PE Heasley, PB Garlick, MA Smith, RD Rubens, MN Maiseyand MA Richards Biochemical Society Transactions 17, 1053-1054, 1989 70. The measurement and visualisation of vessel blood flow by magnetic resonance imaging MA Smith Clinical Physics and Physiological Measurement 11,2, 101-123, 1990 71. A method for characterising localisation techniques in volume selected nuclear magnetic resonance spectroscopy SF Keevil, DA Porter and MA Smith Physics in Medicine and Biology 35(7), 821-834, 1990 72. The measurement of time-averaged flow by magnetic resonance imaging using continuous acquisition in the carotid arteries and its comparison with Doppler ultrasound M Tarnawski, S Padayachee, DJ West, MJ Graves, V Ayton, MG Taylor and MA Smith Clinical Physics and Physiological Measurement 11(1), 27-36, 1990 73. Measurement of time-averaged flow in the middle cerebral artery by magnetic resonance imaging M Tarnawski, S Padayachee, MJ Graves, V Ayton, MG Taylor and MA Smith British Journal of Radiology 64, 178-181, 1991 74. Visibility of phosholopids in 31P NMR spectra of human breast tumours in-vivo M Lowry, DA Porter, CJ Twelves, PE Heasley, MA Smith and MA Richards NMR in Biomedicine 5, 37-42, 1992 75. Experimental characterisation of the ISIS Technique for volume selected NMR spectroscopy SF Keevil, DA Porter and MA Smith NMR in Biomedicine 5, 200-208, 1992 76. Rapid dynamic contrast-enhanced magnetic resonance imaging of the liver and portal vein J Ward, D Martinez, AG Chalmers, J Ridgway, P Robinson and MA Smith British Journal of Radiology 66, 214-222, 1993 77. Phosphorus-31 metabolism of human breast - an in-vivo magnetic resonance spectroscopy study at 1,5T CJ Twelves, M Lowry, DA Porter, NA Dobbs, PE Graves, MA Smith and MA Richards British Journal of Radiology 67, 36-45, 1994 78. Phosphorus-31 metabolism of post-menopausal breast cancer studied in vivo by magnetic resonance CJ Twelves, DA Porter, M Lowry, NA Dobbs, PE Graves, MA Smith, Rubens RD and MA Richards British Journal of Cancer 69(6), 1151-6, 1994 79. Stepping-table gadolinium-enhanced digital subtraction MR angiography of the aorta and lower extremity arteries: preliminary experience JF Meaney, JP Ridgway, S Chakraverty, I Robertson, D Kessel, A Radjenovic, M Kouwenhoven, A Kassner and MA Smith Radiology 211(1), 59-67, 1999 80. Quantitative comparison of intrabrain diffusion in adults and preterm and term neonates and infants SF Tanner, LA Ramenghi, JP Ridgway, E Berry, MA Saysell, D Martinez, RJ Arthur, MA Smith and Ml Levene American Journal of Roentgenology 174(6), 1643-9, 2000 81. A systematic review of the precision and accuracy of dose measurements in photon radiotherapy using polymer and Fricke MRI gel dosimetry ND MacDougall, WG Pitchford and MA Smith Physics in Medicine and Biology 47, 107-121, 2002 Response to comments: Physics in Medicine and Biology 48, L19 - 22, 2003 82. Cerebral perfusion in infants and neonates: preliminary results obtained using dynamic susceptibility contrast enhanced MRI SF Tanner, LG Cornette, LA Ramenghi, LS Miall, JP Ridgway, MA Smith and Ml Levene Archives for Disease in Childhood 88(6), F525-530, 2003 83. Evaluation of the dosimetric performance of BANG3 polymer gels ND MacDougall, ME Miquel, DJ Wilson, SF Keevil and MA Smith Physics in Medicine and Biology 50, 1717 - 1726, 2005 84. T1 measurement using a short acquisition period for quantitative cardiac applications DM Higgins, JP Ridgway, A Radjenovic, UM Sivananthan, and MA Smith Medical Physics 32, 1738-1746, 2005 85. A method for pharmacokinetic modeling of dynamic contrast enhanced MRI studies of rapidly enhancing lesions acquired in a clinical setting A Radjenovic, JP Ridgway and MA Smith Physics in Medicine and Biology 51, N187-N197, 2006 • PATENTS (COPIES NOT INCLUDED) • 86. Surface coils for magnetic resonance imaging MA Smith 1986 87. Sympathetic resonance in magnetic resonance imaging MA Smith 198

The role of the microcirculation in skeletal muscle function and plasticity

The skeletal muscle microcirculation is crucial for the delivery of oxygen and nutrients, and the removal of waste products, but the importance of capillarisation for skeletal muscle performance and hypertrophy is yet to be fully elucidated. Therefore, the aim of the thesis was to assess, in rodents and humans, the role of capillarisation in skeletal muscle fatigue resistance and hypertrophy in health, disease (chronic heart failure (CHF) in particular) and ageing and to determine to what extent baseline muscle mass affects the hypertrophic response. Through the use of microsphere injection to block up to 70% of capillaries in the m. extensor digitorum longus (EDL) it was shown that functional capillary density is positively related to the fatigue resistance of a muscle. The reduction in fatigue resistance as a consequence of unbiased blockage of capillaries can be overcome by overload-induced angiogenesis, and in the case of the rats with compensatory cardiac hypertrophy (a model for hypertension and early chronic heart failure (CHF)) by endurance exercise. CHF reduces functional capillary density in muscle and impairs the hypertrophic response to overload. Given the inverse relationship between fibre cross-sectional area (FCSA) and oxidative capacity, it was expected that the FCSA of highly-resistance trained men would decrease as their oxidative capacity increased with endurance training, with even greater reductions in FCSA in old resistance-trained men. This was, however, not the case probably because the endurance exercise-induced angiogenesis reduced intercapillary distances, facilitating the oxygen delivery via diffusion to the increased number of mitochondria in the muscle fibres. In mice it was seen that the inclusion of hypertrophic and endurance stimuli did not blunt the adaptations to either modality and that baseline muscle mass was not predictive of hypertrophic response in young mice. It was shown, however that old mice demonstrated less hypertrophy, which was associated with an impaired overload-induced angiogenesis. In conclusion, the microcirculation plays a crucial role in skeletal muscle fatigue resistance and is important in reducing diffusion distances with hypertrophy. As such, it appears to be a useful therapeutic target to maintain muscle function and enhance muscle responses to rehabilitation in disease and old age

Volume 22, issue 2

The mission of CJS is to contribute to the effective continuing medical education of Canadian surgical specialists, using innovative techniques when feasible, and to provide surgeons with an effective vehicle for the dissemination of observations in the areas of clinical and basic science research. Visit the journal website at http://canjsurg.ca/ for more.https://ir.lib.uwo.ca/cjs/1160/thumbnail.jp