Browsing by Author "Ackermann, Christelle"

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    Closure of pulmonary arterio-venous malformations in a patient with a novel form of Hereditary Haemorrhagic Telangiectasia
    (South African Heart Association, 2014) Weich, Hellmuth; Ackermann, Christelle
    Image in Cardiology: Hereditary Haemorrhagic Telangiectasia.
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    Diffusion tensor imaging point to ongoing functional impairment in HIV-infected children at age 5, undetectable using standard neurodevelopmental assessments
    (BMC (part of Springer Nature), 2020-05-19) Ackermann, Christelle; Andronikou, Savvas; Saleh, Muhammad G.; Kidd, Martin; Cotton, Mark F.; Meintjes, Ernesta M.; Laughton, Barbara
    Background: Perinatal HIV infection negatively impacts cognitive functioning of children, main domains affected are working memory, processing speed and executive function. Early ART, even when interrupted, improves neurodevelopmental outcomes. Diffusion tension imaging (DTI) is a sensitive tool assessing white matter damage. We hypothesised that white matter measures in regions showing HIV-related alterations will be associated with lower neurodevelopmental scores in specific domains related to the functionality of the affected tracts. Methods: DTI was performed on children in a neurodevelopmental sub study from the Children with HIV Early Antiretroviral (CHER) trial. Voxel-based group comparisons to determine regions where fractional anisotropy and mean diffusion differed between HIV+ and uninfected children were done. Locations of clusters showing group differences were identified using the Harvard–Oxford cortical and subcortical and John Hopkins University WM tractography atlases provided in FSL. This is a second review of DTI data in this cohort, which was reported in a previous study. Neurodevelopmental assessments including GMDS and Beery-Buktenica tests were performed and correlated with DTI parameters in abnormal white matter. Results: 38 HIV+ children (14 male, mean age 64.7 months) and 11 controls (4 male, mean age 67.7 months) were imaged. Two clusters with lower fractional anisotropy and 7 clusters with increased mean diffusion were identified in the HIV+ group. The only neurodevelopmental domain with a trend of difference between the HIV+ children and controls (p = 0.08), was Personal Social Quotient which correlated to improved myelination of the forceps minor in the control group. As a combined group there was a negative correlation between visual perception and radial diffusion in the right superior longitudinal fasciculus and left inferior longitudinal fasciculus, which may be related to the fact that these tracts, forming part of the visual perception pathway, are at a crucial state of development at age 5. Conclusion: Even directed neurodevelopmental tests will underestimate the degree of microstructural white matter damage detected by DTI. The visual perception deficit detected in the entire study population should be further examined in a larger study.
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    Is anomalous origin of the left vertebral artery indeed a rare finding?
    (AOSIS Publishing, 2012-11-28) Van der Merwe, Braham; Ackermann, Christelle; Scheepers, Shaun; Moosa, Sulaiman
    We present a pictorial review of anomalous origin of the left vertebral artery observed in 5 patients imaged in our after-hours trauma radiology unit within a period of 7 days. We raise the question of whether the incidence of anomalous origin of the left vertebral artery quoted in the radiology literature as 5% is really that low, and suggest that the current increased frequency of cross-sectional imaging could elevate the observed incidence of this anomaly in practice. We discuss the implications of vertebral artery anomalies in the endovascular treatment of aortic arch injuries.
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    Mammography reporting at Tygerberg Hospital, Cape Town, South Africa
    (Health & Medical Publishing Group, 2014-07) Pitcher, Richard; Lotz, Jan; Ackermann, Christelle; Bagadia, Asif; Davis, Razaan; Du Plessis, Anne-Marie; Griffith-Richards, Stephanie; Hattingh, Retha; Wagener, Georg; Apffelstaedt, Justus; Dalmayer, Lisa; Baatjes, Karin
    In their recent article, Apffelstaedt et al.[1] analysed 16 105 mammograms performed at Tygerberg Hospital (TBH), Cape Town, South Africa (SA), between 2003 and 2012. The summary reported that ‘mammograms were read by experienced breast surgeons’, while the discussion stated: ‘A further noteworthy fact is that this TBH series was based exclusively on mammography interpretation by surgeons with a special interest in breast health.’ The suggestion that mammograms were exclusively interpreted by breast surgeons does not reflect the mammography workflow at our institution.
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    Neuro-imaging in paediatric HIV, a MRI/DTI study
    (Stellenbosch : Stellenbosch University, 2020-03) Ackermann, Christelle; Cotton, Mark F.; Andronikou, Savvas; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Paediatrics and Child Health.
    ENGLISH ABSTRACT: The HIV epidemic has been largely controlled by antiretroviral treatment (ART) which improves neurodevelopmental outcomes. Nevertheless, many HIV-infected (HIV+) children on long-term treatment may have HIV-related brain injury, ongoing cognitive impairment and treatment-related neurological complications. Magnetic resonance imaging (MRI) and in particular diffusion tensor imaging (DTI) are sensitive tools in assessing the integrity of white matter (WM) microstructure in HIV. The pictorial review describes common causes of HIV-related cerebral WM disease as well as the role of neuro-imaging in managing these patients. In the following chapters the characteristics of WM signal abnormalities on MRI and DTI (using DTI derived measures - fractional anisotropy (FA), mean (MD), axial (AD) and radial diffusion (RD)) in children with HIV, recruited as part of the Children with HIV early antiretroviral (CHER) trial and who started ART within the first year of life, are described. In the CHER trial, infants were randomized to early limited or deferred continuous ART. Methods: Structural MRI scans of children at mean age 39.1 months were reviewed and correlated with clinical and neurodevelopmental data, virological markers and time on ART. DTI was acquired in a similar cohort (which included several children in the first study and control subjects) at mean age of 64.7 months. Voxel-based group comparisons were performed to determine regions where FA and MD differed between HIV+ and uninfected children. Associations of DTI parameters with timing of ART initiation and correlations of DTI parameters in abnormal WM with directed neurodevelopmental tests were examined. Results: MRI scans of 44 children were reviewed at mean age of 39.1 months: 10 on deferred and 34 on early CHER treatment arms, commencing ART at mean age of 18.5 and 8 weeks respectively. Multiple high signal intensity lesions on T2 /FLAIR were documented in 22 patients (50%), predominantly in frontal (91%) and parietal (82%) WM. There were no differences in neurodevelopmental scores in children with and without WM signal abnormalities. Neither lesion load nor distribution showed significant correlation with neurodevelopmental scores or neurological examination. There was a trend for association of WM signal abnormalities and longer time on ART (p=0.13) and nadir CD4% (p=0.08). 39 HIV+ children (15 male) and 13 controls (5 male) were imaged (using DTI) at mean age of 64.7 months. 2 Clusters with decreased FA and 7 clusters with increased MD were identified in the HIV+ group with symmetrical distribution predominantly due to increased RD, suggestive of decreased myelination. Children on early interrupted ART had lower FA compared to those receiving continuous treatment. The only neurodevelopmental domain with a trend of difference between the HIV+ children and controls (p=0.08), was personal social quotient which correlated to improved myelination of the forceps minor in the control group. As a combined group there was a negative correlation between visual perception and RD in the right superior longitudinal fasciculus and left inferior longitudinal fasciculus which may be related to these tracts, part of the visual perception pathway, are at a crucial state of development at age 5. Conclusion: Half of children at mean age of 39.1 months, referred with HIV-related brain disease had WM signal abnormalities on T2/FLAIR structural MRI. HIV+ children at 5 years have WM abnormalities measured by FA, despite early ART, confirming that early ART does not fully protect the WM either from peripartum or in utero infection. In contrast to adults, the corticospinal tracts are predominantly involved rather than the corpus callosum. Continuous early ART, however limits the extent of WM damage. Even directed neurodevelopmental tests will underestimate the degree of microstructural WM damage detected by DTI. The visual perception deficit detected in the HIV study population should be further examined as it persists in longitudinal follow up of these patients at age 7.