Magnetic resonance imaging: Clinical experience with an open low-field-strength scanner in a resource challenged African state

Epidemiology and Management Trends of Neuro-Oncology in Nigeria: A Systematic Review and Pooled Analysis

OBJECTIVE

Access to neuro-oncologic care in Nigeria has grown exponentially since the first reported cases in the mid-1960s. In this systematic review and pooled analysis, we characterize the growth of neurosurgical oncology in Nigeria and build a reference paper to direct efforts to expand this field.

METHODS

We performed an initial literature search of several article databases and gray literature sources. We included and subsequently screened articles published between 1962 and 2021. Several variables were extracted from each study, including the affiliated hospital, the number of patients treated, patient sex, tumor pathology, the types of imaging modalities used for diagnosis, and the interventions used for each individual. Change in these variables was assessed using Chi-squared independence tests and univariate linear regression when appropriate.

RESULTS

A total of 147 studies were identified, corresponding to 5,760 patients. Over 4000 cases were reported in the past 2 decades from 21 different Nigerian institutions. The types of tumors reported have increased over time, with increasingly more patients being evaluated via computed tomography (CT) and magnetic resonance imaging (MRI). There is also a prevalent use of radiotherapy, though chemotherapy remains an underreported treatment modality.

CONCLUSIONS

This study highlights key trends regarding the prevalence and management of neuro-oncologic pathologies within Nigeria. Further studies are needed to continue to learn and guide the future growth of this field in Nigeria.

MRI TRAINING IN AFRICA

Introduction

This article presents an overview of MRI training in Africa, emphasizing its current status and the obstacles it encounters, with a report from a recent MRI workshop held in Uganda in September 2022. Africa's medical imaging sector faces unique challenges due to limited access to advanced technology, skilled professionals, and educational resources. While some regions have made notable strides in establishing MRI training programs, others struggle with a shortage of qualified MRI technicians and radiologists. These disparities underscore the urgent need for a more equitable distribution of resources and expertise across the continent. The aim of the MRI workshop was to initiate actions to address these challenges. This workshop leveraged the expertise of MRI clinicians and scientists to devise strategies for enhancing MRI training in Africa. The report outlines the key outcomes, recommendations, and initiatives resulting from this collaborative endeavor.

Conclusion

This report offers a crucial overview of MRI training in Africa, highlighting its challenges and disparities. It emphasizes the necessity of coordinated efforts to improve MRI education, ultimately contributing to enhanced healthcare outcomes for Africa's population.

Low-field MRI: Clinical promise and challenges

Modern MRI scanners have trended toward higher field strengths to maximize signal and resolution while minimizing scan time. However, high-field devices remain expensive to install and operate, making them scarce outside of high-income countries and major population centers. Low-field strength scanners have drawn renewed academic, industry, and philanthropic interest due to advantages that could dramatically increase imaging access, including lower cost and portability. Nevertheless, low-field MRI still faces inherent limitations in image quality that come with decreased signal. In this article, we review advantages and disadvantages of low-field MRI scanners, describe hardware and software innovations that accentuate advantages and mitigate disadvantages, and consider clinical applications for a new generation of low-field devices. In our review, we explore how these devices are being or could be used for high acuity brain imaging, outpatient neuroimaging, MRI-guided procedures, pediatric imaging, and musculoskeletal imaging. Challenges for their successful clinical translation include selecting and validating appropriate use cases, integrating with standards of care in high resource settings, expanding options with actionable information in low resource settings, and facilitating health care providers and clinical practice in new ways. By embracing both the promise and challenges of low-field MRI, clinicians and researchers have an opportunity to transform medical care for patients around the world. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY: Stage 6.

The elephant in the room: Intimate partner violence, women, and traumatic brain injury in sub-Saharan Africa

Background

Intimate partner violence (IPV) is a gendered form of violence that has been linked with traumatic brain injury (TBI). The prevalence of IPV in sub-Saharan Africa (SSA) is estimated to be one of the highest globally. Yet, little is known about the association between IPV and TBI in the SSA context. In this scoping review, we examine the intersection between IPV and TBI in SSA to identify gaps, as well as intervention opportunities.

Methods

Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses—Extension for Scoping Review (PRISMA-ScR) guidelines to guide our analyses and reporting, we searched for published articles indexed in the four largest and most comprehensive library databases: Pubmed, Embase, Web of Science and PsychInfo. Given the increasing attention that has been placed on gender disparities and health in recent years, we focused on studies published between 2010 and 2021.

Results

Our search yielded 5,947 articles and 1,258 were IPV and SSA related. Out of this, only ten examined the intersection between IPV and TBI. All focused on outcomes in female populations from South Africa (n = 5), Ghana (n = 3), Uganda (n = 1), and Cameroon (n = 1). They were a mix of qualitative studies (n = 3), neuro-imaging/biomarker studies (n = 3), case studies/reports (n = 2), quantitative surveys (n = 1) and mixed qualitative/quantitative study (n = 1). Six studies evaluated subjective reporting of IPV-induced TBI symptoms such as headaches, sleep disruptions, and ophthalmic injuries. Three examined objective assessments and included Hypothalamic-Pituitary-Adrenal (HPA) dysregulation detected by salivary cortisol levels, magnetic resonance imaging (MRI) including diffusion tensor imaging (DTI) to evaluate brain connectivity and white matter changes. One final study took a forensic anthropology lens to document an autopsy case report of IPV-induced mortality due to physical head and face trauma.

Conclusion

Our findings demonstrate that both subjective and objective assessments of IPV and TBI are possible in “resource-limited” settings. The combination of these outcomes will be critical for viewing IPV through a clinical rather than a cultural lens, and for substantiating the assertion that gender, is indeed, a social determinant of brain health.

The Cinderellas of the scanner: Magnetic resonance imaging 'pre-scan' and 'post-scan' times: Their determinants and impact on patient throughput

Background

Increasing demand for magnetic resonance imaging (MRI) has contributed to extended patient waiting times worldwide. This is particularly true in resource-limited environments, prompting this institutional workflow analysis.

Objective

To determine the ‘pre-’ and ‘post-scan’ times for normal-hour MRI studies conducted at a tertiary-level, public-sector South African hospital and to assess any association with demographic details, patient characteristics, anatomical site and scan parameters. A secondary objective was determination of the average daily MR ‘down’ time.

Methods

A prospective descriptive study stratifying MRI workflow into ‘pre-scan’, ‘scan’, ‘post-scan’ and ‘down’ times. During ‘pre-‘ and ‘post-scan’ times patients occupied the scanner whilst staff performed tasks indirectly contributing to image acquisition. During ‘down’ time no patient occupied the MRI room. ‘Pre-’ and ‘post-scan’ times were compared with demographic details, patient characteristics, anatomical site and study parameters, utilising correlation analysis or analysis of variance (ANOVA).

Results

A total of 223 patients (n = 223) underwent 286 investigations in the 23-day review period. Seventy per cent of routine working time was utilised in image acquisition. The ‘pre-’ and ‘post-scan’ times together accounted for 19% and ‘down’ time for 11% of working time. Prolonged ‘pre-’ and ‘post-scan’ times were independently associated with age less than 12 years, anaesthesia, sedation and immobility (p < 0.01 in all cases). The longest median combined ‘pre-’ and ‘post-scan’ time by anatomical site (cholangiopancreatography, 21:46 min) was more than six times the shortest (pituitary fossa, 3:11 min).

Conclusion

A critical analysis of magnetic resonance ‘pre-’ and ‘post-scan’ times can provide valuable insights into opportunities for enhanced service efficiency.

Magnetic resonance imaging in chronic headache: our experiences and perspectives

Background

Headache is a common symptomatology necessitating hospital consultations. Despite the prohibitive cost to patients in Nigeria, Magnetic resonance imaging (MRI) has become an evaluating tool for headache.

Objectives

To determine the yield of cranial MRI and frequency of significant intracranial lesions among patients with chronic headache.

Methods

A three-year retrospective analysis of cranial MR images and records of patients referred to Medicaid Diagnostic Centre in Abuja, Nigeria on account of chronic headache was done. Data was analyzed using SAS software version 9.3.

Results

150 patients aged 9 to 73 years (mean= 39.5 years) with chronic headache were studied. There were 54 males and 96 females with a ratio of 1:1.8. 48% and 52% had normal and abnormal MRI findings respectively. Although the number with abnormal MRI was higher than those with normal exams, this difference was not significant (p=0.624). The commonest neoplastic and non-neoplastic abnormalities were pituitary macroadenoma (4%) and sinusitis (21.3%) respectively.

Conclusion

In our study, MRI had a low diagnostic yield in patients with chronic headache. Therefore, it is expedient that physicians stratify patients with chronic headache based on red flag signs to determine the need for cranial MRI in view of financial burden.

Clinical Audit of Paediatric Magnetic Resonance Imaging Under Sedation at a Nigerian Tertiary Institution

BACKGROUND

Magnetic resonance imaging (MRI) in paediatric patients requires them to be calm during the procedure to avoid motion artefacts in the acquired images. Sedation and/or anaesthesia is a way to achieve this. We evaluated all paediatric MRI sedations since installation of an MRI device in our hospital.

MATERIAL/METHODS

We retrospectively reviewed 69 paediatric MRI sedations performed over a 5-year period using records of patients' biodata, MRI date, indication, findings and scan time, sources of referral, body region scanned, type, dose, related adverse events and route of administration of sedatives as well as image quality.

RESULTS

The median age and weight of the patients were 24 months {range of 0.3 months (10 days) to 132 months (11 years)} and 11.5 kg (range of 2.6 kg to 42 kg), respectively. Males constituted 50.7% of the patients. Most participants (94.2%) were in-patients of the hospital, mainly (60.0%) referred from the paediatric unit, with slightly over one third (36.2%) of the studies performed in 2015. The commonest indication and scanned body region were macrocephaly (18.8%) and the brain (76.8%), respectively. Hydrocephalus (17.4%) was the commonest MRI finding. Sedation was planned in 66 (95.7%) patients and was successful in 68 (98.6%). Midazolam and the IV route were the commonest sedative agent and route of administration, respectively. Image quality determined by age was fair to good in 68 (98.6%) patients with only 1 patient requiring re-scanning due to motion blur. No adverse events with sedation were recorded.

CONCLUSIONS

Midazolam via the IV route with or without oral route is the drug of choice for MRI sedation in children in our institution with a success rate of about 99%.

Role of Diffusion-weighted Imaging in Acute Stroke Management using Low-field Magnetic Resonance Imaging in Resource-limited Settings

A variety of imaging modalities exist for the diagnosis of stroke. Several studies have been carried out to ascertain their contribution to the management of acute stroke and to compare the benefits and limitations of each modality. Diffusion-weighted imaging (DWI) has been described as the optimal imaging technique for diagnosing acute ischemic stroke, yet limited evidence is available on the value of DWI in the management of ischemic stroke with low-field magnetic resonance (MR) systems. Although high-field MR imaging (MRI) is desirable for DWI, low-field scanners provide an acceptable clinical compromise which is of importance to developing countries posed with the challenge of limited availability of high-field units. The purpose of this paper was to systematically review the literature on the usefulness of DWI in acute stroke management with low-field MRI scanners and present the experience in Nigeria.

Improving Brain Tumor Research in Resource-Limited Countries: A Review of the Literature Focusing on West Africa

Neoplasms of the brain are often overlooked in resource-limited countries. Our literature search via AJOL and PubMed demonstrated that brain tumor research is still a rarity in these regions. We highlight the current status, importance, challenges, and methods of improving brain tumor research in West Africa. We suggest that more attention be given to basic, clinical, and epidemiological brain tumor research by national governments, private organizations, international organizations, non-governmental organizations (NGOs), and individuals in this region.

Diagnostic capability of low- versus high-field magnetic resonance imaging for lumbar degenerative disease

STUDY DESIGN

Cohort study.

OBJECTIVE

To investigate the diagnostic capability of low-field magnetic resonance imaging (MRI) compared with high-field MRI for degenerative disease of the lumbar spine.

SUMMARY OF BACKGROUND DATA

Low-field MRI has several advantages over high-field magnetic resonance systems (easier installation, lower purchase, and maintenance cost). The diagnostic capability of low-field MRI for degenerative disease of the lumbar spine has not been compared with that of high-field MRI.

METHODS

Hundred patients (mean age: 56.3 yr, range: 32-80; F:M = 59:41) with neurogenic claudication or sciatica were studied. All patients underwent MRI of the lumbar spine on both low-field (0.25T) and high-field (1.5T or 3.0T) magnetic resonance systems. Intervertebral disc herniation, central canal, lateral recess, and exit foraminal stenosis as well as nerve root compression at L3-L4, L4-L5, and L5-S1 were evaluated by 2 radiologists for both low- and high-field systems using established reliable grading systems.

RESULTS

There was excellent agreement between low- and high- field MRI with regard to grading the presence and severity of disc herniation (r = 0.92-0.94; P < 0.05), central canal stenosis (r = 0.89-0.91; P < 0.05), lateral recess stenosis (r = 0.81-0.87; P < 0.05), and exit foramen stenosis (r = 0.81-0.89; P < 0.05). Descending or exiting nerve root compression occurred in 52% of patients at L3-L4, L4-L5, or L5-S1 levels, with good agreement between low-field and high-field MRI (r = 0.71-0.76; P < 0.05) for nerve root compression.

CONCLUSION

Excellent reliability between low- and high- field MRI was found for most features of lumbar disc degeneration, with good agreement for nerve root compression. 0.25T MRI was more susceptible to motion artifact, probably due to longer scanning time.

LEVEL OF EVIDENCE

3.