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1.
Clin Radiol ; 78(6): e477-e485, 2023 06.
Article in English | MEDLINE | ID: mdl-36958956

ABSTRACT

AIM: To explain the design and delivery of diagnostic imaging and image-guided intervention services for an international games. The authors share their experiences from the Birmingham Commonwealth Games 2022. MATERIALS AND METHODS: A retrospective analysis was undertaken of anonymised data from the Zillion, Easyvision (RIS and PACS), and Encounter platforms for image viewing, interpretation and reporting during the Games. The data collected included age and gender, type of sport, nature of the injury, and imaging findings with diagnoses. RESULTS: The number of individuals who had radiological investigations at the Birmingham Commonwealth Games was 518 and the vast majority of them were athletes (90 %). The average age of athletes who had imaging was 28 years and that of non-athletes who accessed imaging services was 46.4 years with male predominance. Magnetic resonance imaging was the most frequently used imaging technique and the lower limb was the most frequently imaged body part. Athletes playing netball and beach volleyball had the highest percentage of injuries. CONCLUSION: The authors share their experience from the Birmingham Commonwealth Games 2022 regarding the nuances and challenges in radiology service provision for an international sports event that would be helpful for musculoskeletal radiologists in the design and delivery of similar international events in the future.


Subject(s)
Athletic Injuries , Sports , Male , Humans , Adult , Female , Retrospective Studies , Athletes , Magnetic Resonance Imaging
2.
AJNR Am J Neuroradiol ; 44(3): 274-282, 2023 03.
Article in English | MEDLINE | ID: mdl-36822828

ABSTRACT

BACKGROUND AND PURPOSE: Resting-state fMRI helps identify neural networks in presurgical patients who may be limited in their ability to undergo task-fMRI. The purpose of this study was to determine the accuracy of identifying the language network from resting-state-fMRI independent component analysis (ICA) maps. MATERIALS AND METHODS: Through retrospective analysis, patients who underwent both resting-state-fMRI and task-fMRI were compared by identifying the language network from the resting-state-fMRI data by 3 reviewers. Blinded to task-fMRI maps, these investigators independently reviewed resting-state-fMRI ICA maps to potentially identify the language network. Reviewers ranked up to 3 top choices for the candidate resting-state-fMRI language map. We evaluated associations between the probability of correct identification of the language network and some potential factors. RESULTS: Patients included 29 men and 14 women with a mean age of 41 years. Reviewer 1 (with 17 years' experience) demonstrated the highest overall accuracy with 72%; reviewers 2 and 3 (with 2 and 7 years' experience, respectively) had a similar percentage of correct responses (50% and 55%). The highest accuracy used ICA50 and the top 3 choices (81%, 65%, and 60% for reviewers 1, 2, and 3, respectively). The lowest accuracy used ICA50, limiting each reviewer to the top choice (58%, 35%, and 42%). CONCLUSIONS: We demonstrate variability in the accuracy of blinded identification of resting-state-fMRI language networks across reviewers with different years of experience.


Subject(s)
Brain Mapping , Brain Neoplasms , Male , Humans , Female , Adult , Magnetic Resonance Imaging , Retrospective Studies , Brain Neoplasms/diagnostic imaging , Brain Neoplasms/surgery , Language , Brain/diagnostic imaging , Brain/physiology
3.
S Afr Med J ; 112(3): 201-208, 2022 03 01.
Article in English | MEDLINE | ID: mdl-35380521

ABSTRACT

BACKGROUND: Coronavirus disease (COVID-19) has imposed unprecedented stressors on South Africa (SA)'s healthcare system. Superimposed on the country's quadruple burden of disease, pandemic-related care further exposes existing inequities. Some of these inequities are specific to hospital-based inpatient services, such as the geographical maldistribution of hospital beds, lack of oxygen supplies and assisted ventilation, and scarcity of trained healthcare workers. Certain high-risk groups, such as individuals with cardiometabolic comorbidity, are likely to develop severe COVID-19 disease requiring hospitalisation with potential for a prolonged length of stay (LoS). It may be helpful for health authorities to identify those at risk for prolonged LoS to facilitate appropriate health systems planning. OBJECTIVES: To identify hospital admission laboratory parameters associated with a hospital stay >14 days in patients with COVID-19 pneumonia. METHODS: A retrospective observational study design was used. Laboratory data were obtained from an SA private laboratory for 642 inpatients with suspected or confirmed COVID-19 pneumonia, comprising 7 months of admission laboratory data from six private hospitals in Johannesburg, Gauteng Province. RESULTS: Of 642 hospital admissions for pneumonia, 497 were confirmed to have COVID-19 infection (reverse transcription-polymerase chain reaction test positive). In the COVID-19-positive group, hospital LoS was prolonged in 35.4% of admissions. Univariate analysis demonstrated an association with the following risk factors for prolonged LoS: older age; male sex; high serum creatinine, sodium (Na), chloride, potassium and urea levels and low estimated glomerular filtration rate; raised white blood cell count, lymphopenia, neutrophilia and an elevated neutrophil-to-lymphocyte ratio (NLR); and elevated levels of D-dimers, interleukin-6 (IL-6), and procalcitonin (PCT). The strongest univariate associations (relative risk (RR) ≥2.0) with a hospital stay >14 days were high Na levels, NRL >18, high PCT levels and IL-6 >40 pg/mL. On multivariable analysis, the following factors remained significantly associated with prolonged LoS: older age (RR 1.015 per year of age; 95% confidence interval (CI) 1.005 - 1.024); hypernatraemia (RR 1.80; 95% CI 1.25 - 2.60); hyperkalaemia (RR 1.61; 95% CI 1.18 - 2.20); and neutrophilia (RR 1.47; 95% CI 1.15 - 1.88). CONCLUSIONS: COVID-19 pandemic preparedness requires hospital-based inpatient care to be prioritised in resource-limited settings, and availability of beds and prompt admissions are essential to ensure good clinical outcomes. In this study of COVID-19 patients admitted with pneumonia, multivariable analysis showed older age, hypernatraemia, hyperkalaemia and neutrophilia to be associated with LoS >14 days. This may assist with healthcare systems planning.


Subject(s)
COVID-19 , Pandemics , Hospitals , Humans , Length of Stay , Male , Retrospective Studies , SARS-CoV-2 , South Africa/epidemiology
4.
AJNR Am J Neuroradiol ; 41(4): 583-590, 2020 04.
Article in English | MEDLINE | ID: mdl-32139428

ABSTRACT

BACKGROUND AND PURPOSE: Accurate differentiation between glioblastoma and solitary brain metastasis is of vital importance clinically. This study aimed to investigate the potential value of the inflow-based vascular-space-occupancy MR imaging technique, which has no need for an exogenous contrast agent, in differentiating glioblastoma and solitary brain metastasis and to compare it with DSC MR imaging. MATERIALS AND METHODS: Twenty patients with glioblastoma and 22 patients with solitary brain metastasis underwent inflow-based vascular-space-occupancy and DSC MR imaging with a 3T clinical scanner. Two neuroradiologists independently measured the maximum inflow-based vascular-space-occupancy-derived arteriolar CBV and DSC-derived CBV values in intratumoral regions and peritumoral T2-hyperintense regions, which were normalized to the contralateral white matter (relative arteriolar CBV and relative CBV, inflow-based vascular-space-occupancy relative arteriolar CBV, and DSC-relative CBV). The intraclass correlation coefficient, Student t test, or Mann-Whitney U test and receiver operating characteristic analysis were performed. RESULTS: All parameters of both regions had good or excellent interobserver reliability (0.74∼0.89). In peritumoral T2-hyperintese regions, DSC-relative CBV (P < .001), inflow-based vascular-space-occupancy arteriolar CBV (P = .001), and relative arteriolar CBV (P = .005) were significantly higher in glioblastoma than in solitary brain metastasis, with areas under the curve of 0.94, 0.83, and 0.72 for discrimination, respectively. In the intratumoral region, both inflow-based vascular-space-occupancy arteriolar CBV and relative arteriolar CBV were significantly higher in glioblastoma than in solitary brain metastasis (both P < .001), with areas under the curve of 0.91 and 0.90, respectively. Intratumoral DSC-relative CBV showed no significant difference (P = .616) between the 2 groups. CONCLUSIONS: Inflow-based vascular-space-occupancy has the potential to discriminate glioblastoma from solitary brain metastasis, especially in the intratumoral region.


Subject(s)
Brain Neoplasms/diagnostic imaging , Glioblastoma/diagnostic imaging , Image Interpretation, Computer-Assisted/methods , Magnetic Resonance Imaging/methods , Neoplasm Metastasis/diagnostic imaging , Neuroimaging/methods , Adolescent , Adult , Brain Neoplasms/pathology , Contrast Media , Diagnosis, Differential , Female , Glioblastoma/pathology , Humans , Male , Middle Aged , Radionuclide Imaging/methods , Reproducibility of Results , Young Adult
5.
S Afr Med J ; 110(11): 1119-1123, 2020 10 28.
Article in English | MEDLINE | ID: mdl-33403990

ABSTRACT

BACKGROUND: On 26 March 2020, the South African (SA) government initiated a 21-day national level 5 lockdown which was subsequently eased off and downgraded to level 4 on 1 May and to level 3 on 1 June. The effect of lockdown measures on SARS-CoV-2 infectivity is currently uncertain. In this article, we analyse the effects of the lockdown measures on the SARS-CoV-2 epidemic in one of the epicentres in SA. OBJECTIVES: To measure the effects of lockdown measures introduced in SA on SARS-CoV-2 attack rates (ARs, the percentage of individuals who tested positive in a specified time period) in Gauteng Province during a 4-month period (March - June 2020). METHODS: In this retrospective cohort study, we used a comprehensive database from an independent pathology laboratory in Gauteng. We analysed trends of positivity rates of reverse transcription polymerase chain reaction tests done during the 4-month period. The ARs are reported over time (unweighted and age-weighted 14-day moving averages) by age groups, gender, and different regions/districts in Gauteng. RESULTS: A total of 162 528 tests were performed at a private laboratory between 5 March and 30 June 2020, of which 20 574 were positive (overall AR 12.7%). These positive tests constituted 44.8% of all positive cases in the province (20 574/45 944). Sixty-two percent of all tests were done in June during lockdown level 3. There was an exponential increase in the AR in June (18.3%) when lockdown was eased to level 3, in comparison with 4.2% (March), 2.2% (April) and 3.3% (May). The increase in June was seen in all the age groups, although it was more pronounced in the 21 - 60 years age groups than the younger (0 - 20 years) and older (>60 years) age groups. The AR was significantly higher in males (13.2%) compared with females (12.1%) (χ2 test, p<0.0001). CONCLUSIONS: The findings of this study testify to the rapid increase in ARs resulting from easing of the lockdown regulations, especially to level 3 in June. Of concern is the upward trend in the AR across all age groups, especially <20 years (15.9%), which was not reported in other parts of the world. Population age dynamics should therefore be considered when taking future decisions about lockdown regulations.


Subject(s)
COVID-19/prevention & control , Communicable Disease Control , Adolescent , Adult , COVID-19/epidemiology , COVID-19/transmission , COVID-19 Nucleic Acid Testing , Child , Child, Preschool , Cohort Studies , Female , Humans , Incidence , Infant , Infant, Newborn , Male , Middle Aged , Retrospective Studies , SARS-CoV-2 , South Africa/epidemiology , Young Adult
6.
AJNR Am J Neuroradiol ; 39(8): 1493-1498, 2018 08.
Article in English | MEDLINE | ID: mdl-30002054

ABSTRACT

BACKGROUND AND PURPOSE: The supplementary motor area can be a critical region in the preoperative planning of patients undergoing brain tumor resection because it plays a role in both language and motor function. While primary motor regions have been successfully identified using resting-state fMRI, there is variability in the literature regarding the identification of the supplementary motor area for preoperative planning. The purpose of our study was to compare resting-state fMRI to task-based fMRI for localization of the supplementary motor area in a large cohort of patients with brain tumors presenting for preoperative brain mapping. MATERIALS AND METHODS: Sixty-six patients with brain tumors were evaluated with resting-state fMRI using seed-based analysis of hand and orofacial motor regions. Rates of supplementary motor area localization were compared with those in healthy controls and with localization results by task-based fMRI. RESULTS: Localization of the supplementary motor area using hand motor seed regions was more effective than seeding using orofacial motor regions for both patients with brain tumor (95.5% versus 34.8%, P < .001) and controls (95.2% versus 45.2%, P < .001). Bilateral hand motor seeding was superior to unilateral hand motor seeding in patients with brain tumor for either side (95.5% versus 75.8%/75.8% for right/left, P < .001). No difference was found in the ability to identify the supplementary motor area between patients with brain tumors and controls. CONCLUSIONS: In addition to task-based fMRI, seed-based analysis of resting-state fMRI represents an equally effective method for supplementary motor area localization in patients with brain tumors, with the best results obtained with bilateral hand motor region seeding.


Subject(s)
Brain Mapping/methods , Brain Neoplasms/diagnostic imaging , Image Interpretation, Computer-Assisted/methods , Magnetic Resonance Imaging/methods , Motor Cortex/diagnostic imaging , Adolescent , Adult , Aged , Brain Neoplasms/pathology , Female , Humans , Male , Middle Aged , Motor Cortex/pathology , Retrospective Studies , Young Adult
7.
J Neuroimmunol ; 319: 19-27, 2018 06 15.
Article in English | MEDLINE | ID: mdl-29685286

ABSTRACT

Alzheimer's disease (AD) has been genetically and pathologically associated with neuroinflammation. Triggering receptor expressed on myeloid cells 2 (TREM2) is a microglial receptor involved in innate immunity. TREM2 rare protein coding genetic variants have been linked to AD. A soluble TREM2 (sTREM2) cleavage product is elevated in AD. It is unclear whether there is a relationship between elevated sTREM2 and markers of inflammation. The hypothesis of this investigation was that central and peripheral inflammation play a role in sTREM2 levels in AD. A consistent association of peripheral or central markers of inflammation and CSF sTREM2 levels was not found, suggesting a limited impact of general inflammation on sTREM2 levels. An association between peripheral sTREM2 levels and CSF sTREM2, as well as an association between CSF sTREM2 and a marker of blood brain barrier integrity, was observed in AD, suggesting a potential role of peripheral TREM2 in central TREM2 biology.


Subject(s)
Alzheimer Disease/metabolism , Biomarkers/metabolism , Inflammation/metabolism , Membrane Glycoproteins/metabolism , Receptors, Immunologic/metabolism , Aged , Biomarkers/analysis , Female , Humans , Male , Middle Aged
8.
Skeletal Radiol ; 47(2): 173-179, 2018 Feb.
Article in English | MEDLINE | ID: mdl-28856482

ABSTRACT

OBJECTIVE: To establish whether patterns of soft tissue injury following knee hyperextension are associated with post-traumatic 'bone bruise' distribution. MATERIALS AND METHODS: Patients with a knee MRI within one year of hyperextension injury were identified at our institution over a 7 year period. MRIs, plain radiographs and clinical details of these patients were reviewed. RESULTS: Twenty-five patients were identified (median time from injury to MRI = 24 days). The most common sites of bone bruising were the anteromedial tibial plateau (48%) and anterolateral tibial plateau (44%). There were high rates of injury to the posterior capsule (52%), ACL (40%) and PCL (40%) but lower rates of injury to the menisci (20%), medial and lateral collateral ligaments (16%) and posterolateral corner (16%). Anterior tibial plateau oedema and rupture of the posterior capsule predicted cruciate ligament injury [OR = 10.5 (p = 0.02) and 24.0 (p = 0.001) respectively]. Whilst anterolateral tibial plateau oedema strongly predicted PCL injury [OR = 26.0, p = 0.003], ACL injury was associated with a variable pattern of bone bruising. Meniscal injury was unrelated to the extent or pattern of bone bruising. 5 out of 8 patients with a 'double sulcus' on the lateral radiograph had ACL injury. The presence of a double sulcus showed significant association with anteromedial kissing contusions (OR = 7.8, p = 0.03). CONCLUSIONS: Following knee hyperextension, bone bruising patterns may be associated with cruciate ligament injury. Other structures are injured less frequently and have weaker associations with bone bruise distribution. The double sulcus sign is a radiographic marker that confers a high probability of ACL injury.


Subject(s)
Anterior Cruciate Ligament Injuries/diagnostic imaging , Contusions/diagnostic imaging , Knee Injuries/diagnostic imaging , Knee Joint/diagnostic imaging , Magnetic Resonance Imaging/methods , Adolescent , Adult , Diagnosis, Differential , Female , Humans , Male , Middle Aged , Retrospective Studies
9.
AJNR Am J Neuroradiol ; 38(10): E65-E73, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28860215

ABSTRACT

INTRODUCTION: Functional MR imaging is increasingly being used for presurgical language assessment in the treatment of patients with brain tumors, epilepsy, vascular malformations, and other conditions. The inherent complexity of fMRI, which includes numerous processing steps and selective analyses, is compounded by institution-unique approaches to patient training, paradigm choice, and an eclectic array of postprocessing options from various vendors. Consequently, institutions perform fMRI in such markedly different manners that data sharing, comparison, and generalization of results are difficult. The American Society of Functional Neuroradiology proposes widespread adoption of common fMRI language paradigms as the first step in countering this lost opportunity to advance our knowledge and improve patient care. LANGUAGE PARADIGM REVIEW PROCESS: A taskforce of American Society of Functional Neuroradiology members from multiple institutions used a broad literature review, member polls, and expert opinion to converge on 2 sets of standard language paradigms that strike a balance between ease of application and clinical usefulness. ASFNR RECOMMENDATIONS: The taskforce generated an adult language paradigm algorithm for presurgical language assessment including the following tasks: Sentence Completion, Silent Word Generation, Rhyming, Object Naming, and/or Passive Story Listening. The pediatric algorithm includes the following tasks: Sentence Completion, Rhyming, Antonym Generation, or Passive Story Listening. DISCUSSION: Convergence of fMRI language paradigms across institutions offers the first step in providing a "Rosetta Stone" that provides a common reference point with which to compare and contrast the usefulness and reliability of fMRI data. From this common language task battery, future refinements and improvements are anticipated, particularly as objective measures of reliability become available. Some commonality of practice is a necessary first step to develop a foundation on which to improve the clinical utility of this field.


Subject(s)
Algorithms , Brain Mapping/methods , Language , Magnetic Resonance Imaging/methods , Preoperative Care/standards , Adult , Brain Diseases/surgery , Brain Mapping/standards , Child , Female , Humans , Magnetic Resonance Imaging/standards , Male , Preoperative Care/methods , Reproducibility of Results , United States
10.
AJNR Am J Neuroradiol ; 38(5): 1006-1012, 2017 May.
Article in English | MEDLINE | ID: mdl-28364005

ABSTRACT

BACKGROUND AND PURPOSE: Resting-state fMRI readily identifies the dorsal but less consistently the ventral somatomotor network. Our aim was to assess the relative utility of resting-state fMRI in the identification of the ventral somatomotor network via comparison with task-based fMRI in patients with brain tumor. MATERIALS AND METHODS: We identified 26 surgically naïve patients referred for presurgical fMRI brain mapping who had undergone both satisfactory ventral motor activation tasks and resting-state fMRI. Following standard preprocessing for task-based fMRI and resting-state fMRI, general linear model analysis of the ventral motor tasks and independent component analysis of resting-state fMRI were performed with the number of components set to 20, 30, 40, and 50. Visual overlap of task-based fMRI and resting-state fMRI at different component levels was assessed and categorized as full match, partial match, or no match. Rest-versus-task-fMRI concordance was calculated with Dice coefficients across varying fMRI thresholds before and after noise removal. Multithresholded Dice coefficient volume under the surface was calculated. RESULTS: The ventral somatomotor network was identified in 81% of patients. At the subject level, better matches between resting-state fMRI and task-based fMRI were seen with an increasing order of components (53% of cases for 20 components versus 73% for 50 components). Noise-removed group-mean volume under the surface improved as component numbers increased from 20 to 50, though ANOVA demonstrated no statistically significant difference among the 4 groups. CONCLUSIONS: In most patients, the ventral somatomotor network can be identified with an increase in the probability of a better match at a higher component number. There is variable concordance of the ventral somatomotor network at the single-subject level between resting-state and task-based fMRI.


Subject(s)
Brain Mapping/methods , Brain Neoplasms/diagnostic imaging , Magnetic Resonance Imaging/methods , Neural Pathways/diagnostic imaging , Somatosensory Cortex/diagnostic imaging , Brain Neoplasms/surgery , Female , Humans , Linear Models , Male
11.
S Afr J Surg ; 53(1): 19-21, 2015 Mar.
Article in English | MEDLINE | ID: mdl-26489109

ABSTRACT

BACKGROUND: Blunt thoracic aortic injuries (BTAIs) remain a leading cause of death after blunt trauma. In severe injuries, thoracic endovascular aortic repair (TEVAR) has provided a less invasive alternative to conventional open repair. OBJECTIVE: To report the TEVAR-related complications and uncertainties in patients who presented with traumatic pseudoaneurysms (grade III BTAI). METHODS: From April 2004 to February 2012, 55 patients (42 male, mean age 34.7 years) with severe BTAI were treated with stent grafts. Computed tomography (CT) was used to diagnose the injuries, and follow-up scans were planned at 6 and 12 months. We report the complications and the technical uncertainties related to the procedure. RESULTS: Successful sealing of the injury sites was achieved in all patients, either with a thoracic stent graft (53/55) or infrarenal aortic aneurysm extender cuffs (2/55). During hospitalisation, 13 patients died after TEVAR (mean 14 days). Procedure-related complications included left common carotid artery coverage (1/55), ischaemic left leg (1/55) and graft collapse (1/55). The procedurerelated uncertainties included excessive graft oversizing (15/55), poor graft apposition to the inner curve of the aorta (19/55) and left subclavian artery coverage (24/55). CONCLUSION: Stent grafts appear safe and effective in treating pseudoaneurysms caused by BTAI. However, they are likely to be associated with long-term complications and monitoring strategies of >30 years may be necessary.


Subject(s)
Aneurysm, False/therapy , Aorta, Thoracic/injuries , Aortic Aneurysm, Thoracic/therapy , Blood Vessel Prosthesis Implantation , Endovascular Procedures , Wounds, Nonpenetrating/therapy , Adult , Aneurysm, False/etiology , Aortic Aneurysm, Thoracic/etiology , Blood Vessel Prosthesis , Female , Humans , Male , Middle Aged , Retrospective Studies , South Africa , Stents , Treatment Outcome , Wounds, Nonpenetrating/complications , Young Adult
12.
J Nutr Health Aging ; 19(2): 141-53, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25651439

ABSTRACT

BACKGROUND: Non-pharmacological interventions may improve cognition and quality of life, reduce disruptive behaviors, slow progression from Mild Cognitive Impairment (MCI) to dementia, and delay institutionalization. It is important to look at their trial designs as well as outcomes to understand the state of the evidence supporting non-pharmacological interventions in Alzheimer's disease (AD). An analysis of trial design strengths and limitations may help researchers clarify treatment effect and design future studies of non-pharmacological interventions for MCI related to AD. METHODS: A systematic review of the methodology of Randomized Controlled Trials (RCTs) targeting physical activity, cognitive interventions, and socialization among subjects with MCI in AD reported until March 2014 was undertaken. The primary outcome was CONSORT 2010 reporting quality. Secondary outcomes were qualitative assessments of specific methodology problems. RESULTS: 23 RCT studies met criteria for this review. Eight focused on physical activity, fourteen on cognitive interventions, and one on the effects of socialization. Most studies found a benefit with the intervention compared to control. CONSORT reporting quality of physical activity interventions was higher than that of cognitive interventions. Reporting quality of recent studies was higher than older studies, particularly with respect to sample size, control characteristics, and methodology of intervention training and delivery. However, the heterogeneity of subjects identified as having MCI and variability in interventions and outcomes continued to limit generalizability. CONCLUSIONS: The role for non-pharmacological interventions targeting MCI is promising. Future studies of RCTs for non-pharmacological interventions targeting MCI related to AD may benefit by addressing design limitations.


Subject(s)
Alzheimer Disease/therapy , Cognitive Dysfunction/therapy , Randomized Controlled Trials as Topic/methods , Randomized Controlled Trials as Topic/standards , Alzheimer Disease/psychology , Cognition/physiology , Cognitive Dysfunction/psychology , Humans , Institutionalization , Quality of Life
13.
AJNR Am J Neuroradiol ; 36(1): 7-13, 2015 Jan.
Article in English | MEDLINE | ID: mdl-24788129

ABSTRACT

SUMMARY: This review article explains the methodology of breath-hold cerebrovascular reactivity mapping, both in terms of acquisition and analysis, and reviews applications of this method to presurgical mapping, particularly with respect to blood oxygen level-dependent fMRI. Its main application in clinical fMRI is for the assessment of neurovascular uncoupling potential. Neurovascular uncoupling is potentially a major limitation of clinical fMRI, particularly in the setting of mass lesions in the brain such as brain tumors and intracranial vascular malformations that are associated with alterations in regional hemodynamics on either an acquired or congenital basis. As such, breath-hold cerebrovascular reactivity mapping constitutes an essential component of quality control analysis in clinical fMRI, particularly when performed for presurgical mapping of eloquent cortex. Exogenous carbon dioxide challenges used for cerebrovascular reactivity mapping will also be discussed, and their applications to the evaluation of cerebrovascular reserve and cerebrovascular disease will be described.


Subject(s)
Brain Mapping/methods , Cerebral Cortex/physiology , Magnetic Resonance Imaging/methods , Breath Holding , Carbon Dioxide/blood , Hemodynamics/physiology , Humans
14.
AJNR Am J Neuroradiol ; 34(10): 1966-71, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23788599

ABSTRACT

BACKGROUND AND PURPOSE: The optimal paradigm choice for language mapping in clinical fMRI studies is challenging due to the variability in activation among different paradigms, the contribution to activation of cognitive processes other than language, and the difficulties in monitoring patient performance. In this study, we compared language localization and lateralization between 2 commonly used clinical language paradigms and 3 newly designed dual-choice semantic paradigms to define a streamlined and adequate language-mapping protocol. MATERIALS AND METHODS: Twelve healthy volunteers performed 5 language paradigms: Silent Word Generation, Sentence Completion, Visual Antonym Pair, Auditory Antonym Pair, and Noun-Verb Association. Group analysis was performed to assess statistically significant differences in fMRI percentage signal change and lateralization index among these paradigms in 5 ROIs: inferior frontal gyrus, superior frontal gyrus, middle frontal gyrus for expressive language activation, middle temporal gyrus, and superior temporal gyrus for receptive language activation. RESULTS: In the expressive ROIs, Silent Word Generation was the most robust and best lateralizing paradigm (greater percentage signal change and lateralization index than semantic paradigms at P < .01 and P < .05 levels, respectively). In the receptive region of interest, Sentence Completion and Noun-Verb Association were the most robust activators (greater percentage signal change than other paradigms, P < .01). All except Auditory Antonym Pair were good lateralizing tasks (the lateralization index was significantly lower than other paradigms, P < .05). CONCLUSIONS: The combination of Silent Word Generation and ≥1 visual semantic paradigm, such as Sentence Completion and Noun-Verb Association, is adequate to determine language localization and lateralization; Noun-Verb Association has the additional advantage of objective monitoring of patient performance.


Subject(s)
Brain Mapping/methods , Cerebral Cortex/physiology , Functional Laterality , Magnetic Resonance Imaging/methods , Semantics , Adult , Association , Brain Mapping/standards , Female , Healthy Volunteers , Humans , Language , Magnetic Resonance Imaging/standards , Male , Middle Aged , Models, Neurological , Photic Stimulation/methods , Preoperative Care/methods , Reproducibility of Results , Task Performance and Analysis , Young Adult
16.
Int J Nanomedicine ; 7: 4077-88, 2012.
Article in English | MEDLINE | ID: mdl-22888244

ABSTRACT

OBJECTIVE: To investigate cross-linked hydrogels prepared via inverse emulsion polymerization to entrap poorly aqueous soluble drugs. Polyethylene glycol cross-linked acrylic polymers were synthesized and the loading and release of curcumin, a model hydrophobic drug, was investigated. METHODS: Physicochemical characteristics of hydrogels were studied with (13)C nuclear magnetic resonance, Fourier transform infrared spectroscopy, transmission electron microscopy, scanning electron microscopy, differential scanning calorimetry, and swelling. Polymerization of the acrylic acid with cross-linked polyethylene glycol diacrylate was characterized with (13)C nuclear magnetic resonance imaging and Fourier transform infrared spectroscopy. RESULTS: The in vitro release rate of curcumin showed that there was a sustained release from the hydrogel with increased cross-linking; the release rate depended on the pH of the releasing medium. Intracellular and cytotoxicity studies were carried out in human cervical cancer cell lines. CONCLUSION: The results suggest cross-linked acrylic polymers can be used as efficient vectors for pH-sensitive, controlled delivery of hydrophobic drugs.


Subject(s)
Acrylates/chemistry , Antineoplastic Agents/administration & dosage , Drug Delivery Systems/methods , Hydrogels/chemistry , Nanostructures/chemistry , Polyethylene Glycols/chemistry , Acrylates/administration & dosage , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacokinetics , Apoptosis/drug effects , Cell Cycle Checkpoints/drug effects , Cell Survival/drug effects , Curcumin/administration & dosage , Curcumin/chemistry , Curcumin/pharmacokinetics , Dimethyl Sulfoxide , Down-Regulation/drug effects , HeLa Cells , Humans , Hydrogen-Ion Concentration , Hydrophobic and Hydrophilic Interactions , Nanostructures/administration & dosage , Particle Size , Polyethylene Glycols/administration & dosage , Spectroscopy, Fourier Transform Infrared
17.
Curr Med Chem ; 19(36): 6207-13, 2012.
Article in English | MEDLINE | ID: mdl-22834822

ABSTRACT

The main challenge encountered while treating using Paclitaxel (PTX) is its poor solubility in aqueous solutions. The cremophor used in the formulation can cause various side effects such as hypersensitivity, myelosuppression and neurotoxicity and also leads to non-specific distribution in tumor and normal tissues. Since the structure of Paclitaxel does not possess a functional group, it is not easy to manipulate to enhance the solubility. Such limitations can be overcome by delivering Paclitaxel with the aid of drug delivery systems such as polymeric micelles, nanoparticles, hydrogels and liposomes. The review discusses various approaches of Paclitaxel delivery via polymeric nanoparticles. It focuses on the passive and active targeting of Paclitaxel.


Subject(s)
Antineoplastic Agents, Phytogenic/administration & dosage , Drug Carriers/chemistry , Nanoparticles/chemistry , Neoplasms/drug therapy , Paclitaxel/administration & dosage , Polymers/chemistry , Antibodies/immunology , Aptamers, Nucleotide/chemistry , Aptamers, Nucleotide/metabolism , Folic Acid/chemistry , Folic Acid/metabolism , Humans , Hydrogen-Ion Concentration , Peptides/chemistry , Peptides/metabolism , Receptors, Vascular Endothelial Growth Factor/metabolism
18.
Perfusion ; 26(6): 536-41, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21859785

ABSTRACT

BACKGROUND: Adequate perfusion of the right ventricle with retrograde cardioplegia has always been questioned. However, clinical studies suggested sufficient protection and, up to now, intraoperative assessment of cardioplegia distribution has been difficult. METHODS: As a pilot study in 14 patients, we used indocyanine green laser fluorescence angiography (ICGLA) to assess vascular and myocardial perfusion of different areas of the right anterior ventricular wall. Regions of interest were analyzed quantitatively using a new software package. RESULTS: ICGLA allowed rapid and reliable visualization of cardioplegic flow and distribution. Retrograde cardioplegia revealed perfusion defects in the territory of the right anterior cardiac veins when compared to antegrade delivery and to areas close to the left anterior descending vein(s), confirmed by quantitative analyses of maximal fluorescence intensity. Five patients were excluded from quantitative analyses. The learning curve, pitfalls, limitations and special image details are described. CONCLUSION: A larger study is necessary to examine the relevance of perfusion defects to metabolic changes in affected myocytes and to global right ventricular function.


Subject(s)
Fluorescein Angiography/methods , Heart Arrest, Induced/methods , Heart Ventricles/physiopathology , Indocyanine Green , Perfusion/methods , Aged , Aged, 80 and over , Heart Arrest, Induced/adverse effects , Heart Ventricles/pathology , Humans , Lasers , Middle Aged , Perfusion/adverse effects , Ventricular Function, Right
19.
AJNR Am J Neuroradiol ; 32(3): 495-500, 2011 Mar.
Article in English | MEDLINE | ID: mdl-21233229

ABSTRACT

BACKGROUND AND PURPOSE: Anterior scalene block is a helpful diagnostic test for NTOS and a good predictor of surgical outcome. The purpose of this study was to describe the technique, success rate, and complications associated with CT-guided anesthetic and botulinum toxin injection of the ASM/MSM in patients with NTOS symptoms. MATERIALS AND METHODS: One hundred six participants (mean age, 41.5 ± 10 years; 80 women) were identified via a retrospective review of medical records for CT-guided scalene blocks. The procedure was evaluated regarding the technical success, defined as satisfactory detection of the ASM/MSM; intramuscular needle placement; intramuscular injection of contrast; appropriate delivery of medication; and frequency of unintended BP block or other complications. We also determined the outcome of patients who underwent surgery following the block. RESULTS: Study participants underwent 146 scalene injections, 83 blocks, and 63 chemodenervations, which were included in this investigation. In all cases, detection of the ASM/MSM and intramuscular needle placement was satisfactory. Postprocedural complications included 5 (3.4%) temporary BP blocks, 1 patient with (0.7%) Horner sign, 7 (4.8%) needle-induced pain reports, 1 (0.7%) case of dysphagia, and 2 (1.4%) instances of muscle weakness. There were no major complications reported. The rate of good outcome following surgery was the same in patients with positive versus negative blocks, 30/43 (70%) versus 5/7 (71%), respectively. CONCLUSIONS: CT guidance is a useful adjunct in performing accurate ASM/MSM blocks with a low rate of minor complications.


Subject(s)
Anesthetics, Local/administration & dosage , Muscle Weakness/epidemiology , Muscle, Skeletal/drug effects , Nerve Block/statistics & numerical data , Pain/epidemiology , Radiography, Interventional/statistics & numerical data , Tomography, X-Ray Computed/statistics & numerical data , Adult , Aged , Female , Humans , Incidence , Injections, Intramuscular/methods , Injections, Intramuscular/statistics & numerical data , Male , Maryland/epidemiology , Middle Aged , Risk Assessment , Risk Factors , Young Adult
20.
AJNR Am J Neuroradiol ; 31(2): 219-25, 2010 Feb.
Article in English | MEDLINE | ID: mdl-20150316

ABSTRACT

BOLD fMRI has, during the past decade, made a major transition from a purely research imaging technique to a viable clinical technique used primarily for presurgical planning in patients with brain tumors and other resectable brain lesions. This review article briefly examines the history and evolution of clinical functional imaging, with particular emphasis on how the use of BOLD fMRI for neurosurgical planning has changed during the past 2 decades. Even more important, this article describes the many published studies during that same period that have examined the overall clinical impact that BOLD and DTI have made on surgical planning.


Subject(s)
Brain Neoplasms/history , Magnetic Resonance Imaging/history , Neuroradiography/history , Neurosurgical Procedures/history , Brain Neoplasms/diagnosis , Brain Neoplasms/surgery , History, 20th Century , History, 21st Century , Humans
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