A review of MRI studies in Africa with special focus on quantitative MRI: Historical development, current status and the role of medical physicists.

This scoping review provides overview on the historical and major developments, current status, quantitative magnetic resonance (MR) studies and the role of medical physics bodies in MR imaging in Africa. The study analyzed MRI availability in 32 (59 %) of the 54 African countries. South Africa and Egypt have the most dominant MR systems. Number of MR systems in the 4 northern countries (Egypt, Morocco, Algeria and Libya) alone constitute 53 % of the total number of machines in the studied countries. Less than one-third of the countries have 1 MR system serving less than a million population. Libya recorded the most MR systems per million population. The studied countries altogether have an average of 1 machine per million population. The private sector far dominates number of installed MR systems across the region, making up two-thirds of the distribution. A major challenge was revealed where less than 3 % of Medical Physicists in the studied countries are engaged in MRI facilities. Review of MRI published studies in the last 5 years indicates dominance of literature on brain studies and most of such published works coming from Nigeria. Only 7 out of 27 published studies reviewed were quantitative. The African region has no dedicated MRI physics societies; however, the regional medical physics body and national associations have big roles to play in developing MRI through education, research, training and leveraging on awareness creation. Thisreview is the first of such wide scale study on MRI availability and quantitative studies in the African region.

ESTABLISHMENT OF REGIONAL DIAGNOSTIC REFERENCE LEVELS IN ADULT COMPUTED TOMOGRAPHY FOR FOUR AFRICAN COUNTRIES: A PRELIMINARY SURVEY.

This preliminary study aims towards the establishment of regional diagnostic reference levels (DRLs) for routine adult computed tomography (CT) examinations. The study was performed on 54 CT facilities from four African countries (Ghana, Kenya, Namibia and Senegal) and the results compared with international DRLs. Data were collected from facilities using a structured questionnaire provided by the International Atomic Energy Agency. Dose descriptors (volume computed tomography dose index [CTDIvol] and dose length product [DLP]) evaluations were performed on CT head and body phantoms for head, chest and abdomen CT examination protocols using standard methods. The estimated dose indices were compared with console-displayed dose values. Experienced radiologists accepted the diagnostic image quality of the images as per departmental imaging requirements. Median CTDIvol and DLP data from each facility were compiled to estimate the typical dose in each country. National DRLs were established based on the 75th percentile of median values, whereas the regional DRLs were based on the median of the national DRLs. Comparison of measured CTDIvol with console values of all facilities in all four countries was within 20% as recommended. The established CTDIvol DRLs for head CT, chest CT and abdomen CT were 60.9 mGy, 15.2 mGy and 15.7 mGy, respectively. Similarly, that of DLP, DRLs were 1259 mGy.cm, 544 mGy.cm and 737 mGy.cm, respectively for head CT, chest CT and abdomen CT. The established DRLs from this study were comparable to DRLs from other countries with some variations. This study would serve as baseline for establishment of a more generalized regional adult CT DRLs for Africa.

Rare earth elements in uranium ore deposits from Namibia: A nuclear forensics tool.

Rare earth elements (REE) concentrations and pattern remains largely unchanged during the process of milling and can thus provide strong evidence of the origin of the material. The aim of this study was to determine the rare earth elements in uranium ore deposits as a nuclear forensics tool. Uranium ore from three mines were collected and analyzed using an inductively coupled plasma mass spectrometry (ICP-MS) to determine the concentrations of rare earth elements. A non-parametric Kruskal-Wallis test and a pair wise comparison test was used to test for significant difference in the concentration of REEs between the mines followed by principal component analysis (PCA). The REE concentration were normalized with C1-Chondrite values to determine the REE pattern. The total concentration of the REE ranged from 131.38 to 161.77 ppb, 266.27 to 840.37 ppb, 177.86 to231.51 for Mine 1, 2 and 3, respectively. The mean ∑REE obtained was in the order M2>M3>M1. The pairwise comparison test of the pair M1 and M2 was found to be less than 0.05, indicating a significant difference in the samples. The REE pattern is mostly similar for all the ore samples with pronounce Eu anomaly, enriched LREE and depleted flat HREE. The PCA results indicates that the ore samples can be distinguished from each other.