Browsing by Author "Spottiswoode, Bruce"

Now showing 1 - 7 of 7
  • Thumbnail Image
    Item
    Restricted
    Abnormal diastolic and systolic septal motion following pericardiectomy demonstrated by cine DENSE MRI
    (Clinics Cardive, 2008) Spottiswoode, Bruce; Russell, James B; Moosa, Sulaiman; Meintjes, Ernesta M; Epstein, Frederick H; Mayosi, Bongani M
    Constrictive pericarditis can lead to paradoxical interventricular septal motion. Displacement encoding with stimulated echoes (DENSE) magnetic resonance imaging (MRI) provides a method for quantifying myocardial motion and strain. A case of constrictive pericarditis is presented and the diastolic ‘septal bounce’ is clearly evident in both anatomical and DENSE ciné MRI images. (See video link to full-text electronic article). The postoperative systolic septal wall-motion abnormality of cardiac surgery is portrayed with greater precision by DENSE than anatomical ciné MRI images.
  • Thumbnail Image
    Item
    Open Access
    Assessing strain in arrhythmogenic right ventricular cardiomyopathy using cine DENSE MRI
    (BioMed Central Ltd, 2009) Ongori, Joash; Hendricks, Neil; Spottiswoode, Bruce; Meintjes, Ernesta; Epstein, Frederick; Mayosi, Bongani
    The kinematics of the right ventricle (RV) are not well understood due to its thin wall and asymmetric geometry. Cine displacement encoding with stimulated echoes (cine DENSE), which measures intramyocardial displacement and strain, has been adapted for RV analysis with encouraging preliminary results in normal subjects. This preliminary study evaluates cine DENSE MRI for detecting decreased myocardial strain in arrhythmogenic right ventricular cardiomyopathy (ARVC). ARVC is a unique heart muscle disease affecting predominantly the RV. The pathological hallmark of fibro-fatty replacement of the myocardium may result in localised aneurysms and wall motion abnormalities, detectable by cardiac magnetic resonance imaging.
  • Thumbnail Image
    Item
    Open Access
    Comparison of SNR efficiencies and strain for cine DENSE using conventional EPI, flyback EPI and spiral k-space trajectories
    (BioMed Central Ltd, 2011) Zhong, Xiaodong; Spottiswoode, Bruce; Meyer, Craig; Epstein, Frederick
    The original implementation of 2D cine DENSE (displacement encoding with stimulated echoes) employed a conventional EPI k-space trajectory for rapid data sampling. Follow-up studies used flyback EPI to reduce image artifacts. More recently a spiral k-space trajectory was utilized for improved SNR.
  • Thumbnail Image
    Item
    Open Access
    Comprehensive Cardiovascular magnetic resonance of myocardial mechanics in mice using three-dimensional cine DENSE
    (BioMed Central Ltd, 2011) Zhong, Xiaodong; Gibberman, Lauren; Spottiswoode, Bruce; Gilliam, Andrew; Meyer, Craig; French, Brent; Epstein, Frederick
    BACKGROUND: Quantitative noninvasive imaging of myocardial mechanics in mice enables studies of the roles of individual genes in cardiac function. We sought to develop comprehensive three-dimensional methods for imaging myocardial mechanics in mice. METHODS: A 3D cine DENSE pulse sequence was implemented on a 7T small-bore scanner. The sequence used three-point phase cycling for artifact suppression and a stack-of-spirals k-space trajectory for efficient data acquisition. A semi-automatic 2D method was adapted for 3D image segmentation, and automated 3D methods to calculate strain, twist, and torsion were employed. A scan protocol that covered the majority of the left ventricle in a scan time of less than 25 minutes was developed, and seven healthy C57Bl/6 mice were studied. RESULTS: Using these methods, multiphase normal and shear strains were measured, as were myocardial twist and torsion. Peak end-systolic values for the normal strains at the mid-ventricular level were 0.29 +/- 0.17, -0.13 +/- 0.03, and -0.18 +/- 0.14 for Err, Ecc, and Ell, respectively. Peak end-systolic values for the shear strains were 0.00 +/- 0.08, 0.04 +/- 0.12, and 0.03 +/- 0.07 for Erc, Erl, and Ecl, respectively. The peak end-systolic normalized torsion was 5.6 +/- 0.9degrees. CONCLUSIONS: Using a 3D cine DENSE sequence tailored for cardiac imaging in mice at 7 T, a comprehensive assessment of 3D myocardial mechanics can be achieved with a scan time of less than 25 minutes and an image analysis time of approximately 1 hour.
  • Thumbnail Image
    Item
    Open Access
    Impact of childhood trauma on functionality and quality of life in HIV-infected women
    (BioMed Central Ltd, 2011) Troeman, Zyrhea; Spies, Georgina; Cherner, Mariana; Archibald, Sarah; Fennema-Notestine, Christine; Theilmann, Rebecca; Spottiswoode, Bruce; Stein, Dan; Seedat, Soraya
    BACKGROUND:While there are many published studies on HIV and functional limitations, there are few in the context of early abuse and its impact on functionality and Quality of Life (QoL) in HIV. METHODS: The present study focused on HIV in the context of childhood trauma and its impact on functionality and Quality of Life (QoL) by evaluating 85 HIV-positive (48 with childhood trauma and 37 without) and 52 HIV-negative (21 with childhood trauma and 31 without) South African women infected with Clade C HIV. QoL was assessed using the Quality of Life Enjoyment and Satisfaction Questionnaire (Q-LES-Q), the Patient's Assessment of Own Functioning Inventory (PAOFI), the Activities of Daily Living (ADL) scale and the Sheehan Disability Scale (SDS). Furthermore, participants were assessed using the Center for Epidemiologic Studies Depression Scale (CES-D) and the Childhood Trauma Questionnaire (CTQ). RESULTS: Subjects had a mean age of 30.1 years. After controlling for age, level of education and CES-D scores, analysis of covariance (ANCOVA) demonstrated significant individual effects of HIV status and childhood trauma on self-reported QoL. No significant interactional effects were evident. Functional limitation was, however, negatively correlated with CD4 lymphocyte count. CONCLUSIONS: In assessing QoL in HIV-infected women, we were able to demonstrate the impact of childhood trauma on functional limitations in HIV.
  • Thumbnail Image
    Item
    Open Access
    Mapping right ventricular myocardial mechanics using 3D cine DENSE cardiovascular magnetic resonance
    (BioMed Central Ltd, 2012) Auger, Daniel; Zhong, Xiaodong; Epstein, Frederick; Spottiswoode, Bruce
    BACKGROUND: The mechanics of the right ventricle (RV) are not well understood as studies of the RV have been limited. This is, in part, due to the RV's thin wall, asymmetric geometry and irregular motion. However, the RV plays an important role in cardiovascular function. This study aims to describe the complex mechanics of the healthy RV using three dimensional (3D) cine displacement encoding with stimulated echoes (DENSE) cardiovascular magnetic resonance (CMR). METHODS: Whole heart 3D cine DENSE data were acquired from five healthy volunteers. Tailored post-processing algorithms for RV mid-wall tissue tracking and strain estimation are presented. A method for sub-dividing the RV into four regions according to anatomical land marks is proposed, and the temporal evolution of strain was assessed in these regions. RESULTS: The 3D cine DENSE tissue tracking methods successfully capture the motion and deformation of the RV at a high spatial resolution in all volunteers. The regional Lagrangian peak surface strain and time to peak values correspond with previous studies using myocardial tagging, DENSE and strain encoded CMR. The inflow region consistently displays lower peak strains than the apical and outflow regions, and the time to peak strains suggest RV mechanical activation in the following order: inflow, outflow, mid, then apex. CONCLUSIONS: Model-free techniques have been developed to study the myocardial mechanics of the RV at a high spatial resolution using 3D cine DENSE CMR. The consistency of the regional RV strain patterns across healthy subjects is encouraging and the techniques may have clinical utility in assessing disrupted RV mechanics in the diseased heart.
  • Thumbnail Image
    Item
    Open Access
    Virtual reality exposure therapy as treatment for pain catastrophizing in fibromyalgia patients: proof-of-concept study (Study Protocol)
    (BioMed Central Ltd, 2011) Morris, Linzette; Grimmer-Somers, Karen; Spottiswoode, Bruce; Louw, Quinette
    BACKGROUND: Albeit exercise is currently advocated as one of the most effective management strategies for fibromyalgia syndrome (FMS); the implementation of exercise as a FMS treatment in reality is significantly hampered by patients' poor compliance. The inference that pain catastrophizing is a key predictor of poor compliance in FMS patients, justifies considering the alteration of pain catastrophizing in improving compliance towards exercises in FMS patients. The aim of this study is to provide proof-of-concept for the development and testing of a novel virtual reality exposure therapy (VRET) program as treatment for exercise-related pain catastrophizing in FMS patients. METHODS: Two interlinked experimental studies will be conducted. Study 1 aims to objectively ascertain if neurophysiological changes occur in the functional brain areas associated with pain catastrophizing, when catastrophizing FMS subjects are exposed to visuals of exercise activities. Study 2 aims to ascertain the preliminary efficacy and feasibility of exposure to visuals of exercise activities as a treatment for exercise-related pain catastrophizing in FMS subjects. Twenty subjects will be selected from a group of FMS patients attending the Tygerberg Hospital in Cape Town, South Africa and randomly allocated to either the VRET (intervention) group or waiting list (control) group. Baseline neurophysiological activity for subjects will be collected in study 1 using functional magnetic resonance imaging (fMRI). In study 2, clinical improvement in pain catastrophizing will be measured using fMRI (objective) and the pain catastrophizing scale (subjective).DISCUSSION:The premise is if exposing FMS patients to visuals of various exercise activities trigger the functional brain areas associated with pain catastrophizing; then as a treatment, repeated exposure to visuals of the exercise activities using a VRET program could possibly decrease exercise-related pain catastrophizing in FMS patients. Proof-of-concept will either be established or negated. The results of this project are envisaged to revolutionize FMS and pain catastrophizing research and in the future, assist health professionals and FMS patients in reducing despondency regarding FMS management.TRIAL REGISTRATION:PACTR201011000264179