Establishing a Local Diagnostic Reference Level for Bone Scintigraphy in a Nigerian Tertiary Hospital.

It is of vital importance to optimize the radiation dose to patients undergoing radionuclide bone scanning. This is one of the most common nuclear medicine procedures in many parts of the world, including Nigeria, and the current study was performed as part of a national survey to establish diagnostic reference levels (DRLs) for common nuclear medicine procedures in Nigeria in order to optimize their use. Nuclear medicine was only recently introduced to the health-care system in Nigeria, with only 2 centers presently conducting these procedures. Methods: A retrospective, cross-sectional study was performed in the nuclear medicine department of a tertiary hospital in southwest Nigeria to determine the preliminary local DRL for radionuclide bone scanning. One hundred and nine patients who met the study criteria were included. Data were obtained from June 2017 to March 2019 and were analyzed to obtain the third quartile of the distributed administered activity and achievable dose (anthropometric variables and radiation dose to bone surface). Results: The mean administered activity, achievable dose, and DRL were 833.98 ± 106.93, 832.5, and 895.4 MBq, respectively. The calculated preliminary local DRL was larger than values reported in studies done in Sudan, the United Kingdom, and Australia or by the International Commission on Radiological Protection. Conclusion: The preliminary DRL from this first-of-its-kind study in Nigeria was high because of practitioners' lack of experience. However, the values were still within the international best-practice range, which when optimized will go a long way toward reducing medical exposure without compromising image quality.

Bone mineral density in an urban and a rural children population-A comparative, population-based study in Enugu State, Nigeria.

INTRODUCTION: Osteoporosis is one of the non-communicable diseases linked to urbanisation. The foundation of osteoporotic fractures stems from childhood. Therefore, studies that promote maximising peak bone mass are strongly advocated. Studies have shown that there are differences in the incidence of osteoporotic fractures in rural and urban communities. No study has investigated urban-rural differences in BMD of Nigerian children. This study, therefore, aimed to investigate urban-rural differences in BMD of Nigerian children and the association with physical activity, demographic and anthropometric variables. METHODS: In a cross-sectional, study in Enugu, Nigeria, estimated bone mineral density (eBMD) was measured at the calcaneum using the QUS densitometer, Hologic Sahara, in 457 urban (Enugu metropolis) and 559 rural (Nsukka community) children aged 6-14 years. Height, weight and physical activity were measured. Independent sample t-test was used for comparative analysis while Pearson correlation coefficients and multiple regression models were used to examine the relationship between the eBMD and the other parameters. RESULTS: The mean (S.D) eBMD of the urban children [0.52(0.09) g/cm2] were significantly higher (p < 0.05) than their age- and gender-matched counterparts in the rural areas [0.51(0.08) g/cm2]. Age and weight predicted (p < 0.05) the eBMD in the urban subjects while only age was the predictor (p < 0.05) in the rural subjects. The physical activity pattern had no relationship with eBMD in both urban and rural children in Enugu, Nigeria. CONCLUSIONS: The eBMD of rural children is lower than that of their age- and gender-matched urban counterparts.

Calcaneal Broadband Ultrasound Attenuation and Speed of Sound Measurements in a Population of Nigerian Children: Reference Data and the Influence of Sociodemographic Variables.

OBJECTIVES: The aim of our study was to establish a reference database of calcaneal broadband ultrasound attenuation (BUA) and the speed of sound (SOS) in a healthy Nigerian population of children aged 6 to 14 years and also to investigate the influence of sociodemographic and anthropometric variables on them. METHODS: The BUA and SOS of 1016 healthy children were measured by quantitative ultrasound densitometry. Height and weight were measured with a stadiometer and weighing balance, respectively, whereas the sociodemographic parameters of the participants were collected on a semistructured questionnaire. A multiple regression model using stepwise selection and Pearson correlation coefficients were used to examine the relationship between the ultrasound parameters and sociodemographic and anthropometric parameters. Comparisons between various age groups were made by analysis of variance. RESULTS: The mean BUA and SOS ± SD of the participants were 60.57 ± 16.21 dB/MHz and 1563.48 ± 21.74 m/s, respectively, for boys and 58.18 ± 15.16 dB/MHz and 1560.03 ± 22.32 m/s for girls. The BUA in both sexes was positively influenced by age and weight (P < .05), whereas only the father's educational status was its predictor (P < .05) in the boys. For the girls, the family size and mother's educational status were predictors of the BUA (P < .05). The SOS was marginally influenced by age and family size in the boys (P < .05), whereas the father's educational status was the predictor in the girls. CONCLUSIONS: The established BUA and SOS values in this study are baseline values, and further study, which would also involve data from a large number of Nigerian children, would be needed to support their effectiveness as reference values.

Determination of the sonic properties of a Nigerian quartz for ultrasonic transducer.

BACKGROUND: There is abundant quartz deposit in Nigeria which has been used for export and building purposes. However, its electrical and piezoelectric properties have not been studied. Thus, whether it can be used as raw material for the indigenous electric industries is unknown to date. OBJECTIVE: This study aims to characterize the piezoelectric properties of smoky quartz for ultrasonic transducer and determine its sonic properties. METHOD: In the research approach, the raw quartz was cut into six crystals of rectangular shape using a universal cutter. The crystals were purified with a 100 ml hydrofluoric and hydrochloric acid solution under a temperature of 250°C in a furnace. The sizes, weights, and capacitance of crystals were determined using the standard measuring instruments. The resonance method was used for the determination of the frequency of minimum and maximum impedance of the crystals. The piezoelectric constants of the crystals were derived using the standard formula for determination of piezoelectric constants. RESULTS: The results show that the sonic properties represented by the piezoelectric charge constant (d31) and the piezoelectric voltage constant (g31) values are 2.52 (±1.075) ×10-8c/m2 and 1030.6114 ± 250.89v/m2 respectively. CONCLUSION: The present study has characterized Nigerian quartz for its piezoelectric properties and found that it was suitable for use in the construction of ultrasonic transducers.

Sonographic assessment of petroleum-induced hepatotoxicity in Nigerians: does biochemical assessment underestimate liver damage?

BACKGROUND: Exposure to petroleum products has been shown to have significant adverse effects on the liver which can manifest either as morphological or physiological changes. OBJECTIVES: The aim of the study was to assess the effects of chronic exposure to some petroleum products on the liver of exposed workers using sonography and to determine whether biochemical assessments underestimated hepatotoxicity. METHODS: Abdominal ultrasound was performed on 415 exposed workers in order to evaluate liver echogenicity and size. Also, biochemical assessment of the liver was done to evaluate its function. RESULTS: Statistically significant increase in the liver parenchymal echogenicity and the liver size was seen in the exposed workers compared with control (p ≤ 0.05). These increased as the exposure duration increased. It was also noted that out of 16.87% (N=70) exposed workers with abnormal liver echopattern, only 2.65% (N=11) had alanine aminotransferase above the reference range. CONCLUSION: The study revealed evidence of ultrasound detectable hepatotoxicity among the exposed subjects. Sonography appeared to detect petroleum products-induced hepatic toxicity more than biochemical assays suggesting that biochemical assessment may have underestimated toxicity.

Normative ultrasound values of renal parenchymal thickness among adults in Enugu, South-East Nigeria.

BACKGROUND: Reduction in renal length was found to be an insufficient independent indicator of chronic renal disease. OBJECTIVE: To determine the ultrasound normative values of renal parenchymal thickness (RPT) among adults and correlate them with age and somatometric parameters. METHODS: This was a prospective clinic based study involving 310 normal adults (135 males and 175 females) scanned at University of Nigeria Teaching Hospital, Enugu between August 2003 and November 2004. The RPT measurements were made from the outer renal cortical margin to the outer margin of the sinus echoes at the three major poles. The age, height, weight and body mass index were recorded for each subject. RESULTS: The average RPT are 1.85 ± 0.20 cm for the right kidney and 1.95 ± 0.19 cm for the left kidney. RPT exhibited strong positive correlation with height, weight and body mass index and significant negative correlation with age. No significant difference in mean RPT of both kidneys between genders (p > 0.05). The mean RPT of the left kidney was found to be statistically higher than that of the right kidney (p < 0.05). CONCLUSION: Normal values of RPT are important in the evaluation of patients with chronic renal disease.

Gongronema latifolium delays gastric emptying of semi-solid meals in diabetic dogs.

The aim of the study was to investigate sonographically the effect of Gongronema latifolium on gastric emptying of semi-solid meals in diabetic dogs. Twenty-five alloxan-induced diabetic dogs were randomly allotted into five groups of five dogs each in a randomised placebo-controlled study. These are placebo, prokinetic dose, low dose, moderate dose and high dose groups. The placebo group served as the control. The low, moderate and high dose groups ingested methanolic leaf extract of G. latifolium at 100 mg/kg, 250 mg/kg, 500 mg/kg respectively, while the prokinetic group ingested 0.5 mg/kg of metoclopramide. After a 12-hour fast, each group ingested its treatment capsules 30 minutes before the administration of test meal. Measurements of gastric emptying and blood glucose levels were obtained from each dog 30 minutes before and immediately after the ingestion of a test meal, every 15 minutes for another 4 hours and then every 30 minutes for further 2 hours. Gastric emptying of the moderate and high dose groups were 227.8 ± 9.9 min and 261.3 ± 19.3 min respectively and significantly (p < 0.0001) slower than the placebo control group of 143.0 ± 17.8 min. The gastric emptying of the low dose group (169.8 ± 3.8) and control group did not differ significantly (p > 0.05). A strong inverse relationship between gastric emptying and the incremental blood glucose levels was noted in the diabetic dogs after the ingestion of Gongronema latifolium (r = -0.90; p < 0.0001). Gonogronema latifolium delayed gastric emptying in diabetic dogs.

Effect of Gongronema latifolium on gastric emptying in healthy dogs.

AIM: To investigate sonographically the effect of Gonogronema latifolium (G. latifolium) on gastric emptying of semi-solid meals in healthy dogs. METHODS: In a randomized, placebo-controlled experiment, twenty-five clinically healthy dogs were randomly allotted into five groups of five dogs in each group. The placebo group served as the control, and the low, moderate and high dose groups ingested the methanolic leaf extract of G. latifolium in capsules at 100 mg/kg, 250 mg/kg and 500 mg/kg, respectively, while the prokinetic group ingested 0.5 mg/kg capsules of metoclopramide. After a 12-h fast, each group ingested its treatment capsules 30 min before the administration of a test meal. Measurements of gastric emptying and blood glucose levels were obtained 30 min before and immediately after the ingestion of the test meal and thereafter every 15 min for 4 h. This was followed by further measurements every 30 min for another 2 h. RESULTS: The gastric emptying times of the placebo, low dose, moderate dose, high dose and prokinetic dose groups were 127.0 ± 8.2 min, 135.5 ± 3.7 min, 155.5 ± 3.9 min, 198.0 ± 5.3 min and 59.0 ± 2.5 min, respectively. Gastric emptying times of the moderate and high dose groups were significantly slower than in the placebo control group (155.5 ± 3.9 min, 198.0 ± 5.3 min vs 127.0 ± 8.2 min, P = 0.000). No significant difference in gastric emptying between the low dose and placebo control groups was noted (135.5 ± 3.7 min vs 127.0 ± 8.2 min, P = 0.072). Gastric emptying of the prokinetic group was significantly faster than that of the control group (59.0 ± 2.5 min vs 127.0 ± 8.2 min, P = 0.000). The hypoglycaemic effect of G. latifolium and gastric emptying were inversely related (r = -0.95, P = 0.000). CONCLUSION: G. latifolium delays gastric emptying and lowers postprandial blood glucose in healthy dogs. It reduces the postprandial blood glucose by delaying gastric emptying.

Assessment of natural radioactivity in phosphate ore, phosphogypsum and soil samples around a phosphate fertilizer plant in Nigeria.

The radionuclides present in phosphate ore, phosphogypsum and soil samples in the vicinity of a phosphate fertilizer plants in Nigeria were identified and their activity concentration determined to assess the potential radiation impact on the environment due to fertilizer production. The mean activity concentration of (238)U, (232)Th, and (40)K radionuclides in phosphate ore samples were 616 ± 38.6, BDL (Below Detection Level) and 323.7 ± 57.5 Bq kg(-1) respectively. For the phosphogypsum, 334.8 ± 8.8, 4.0 ± 1.4, and 199.9 ± 9.3 Bq kg(-1) respectively and for soil samples range from 20.5 ± 7.3 to 175.7 ± 10.5 Bq kg(-1) for (226)Ra, 15.5 ± 1.5 to 50.4 ± 0.6 Bq kg(-1) for (232)Th and 89.5 ± 8.1 to 316.1 ± 41.3 Bq kg(-1) for (40)K respectively. The mean absorbed dose rate was 71.4 nGy h(-1). The mean annual effective dose was 86 µSv.

Variabilities of gallbladder contraction indices and a simple regression model for gallbladder and gastric emptying ratio.

INTRODUCTION: The objective of this study was to assess the variabilities of gallbladder contraction indices (GBCI) and derive a predictive model for gallbladder and gastric motility. METHODS: The gallbladder volume and gastric antral measurements were obtained from 24 healthy male volunteers in preprandial and post-milk ingestion states. After preprandial measurement of the gallbladder volume and gastric antral area, each subject ingested 157 ml of full cream milk and 30 cl of ion-free water. In supine position, the gallbladder volume and the gastric antral area were obtained every five minutes for 40 minutes. For the gallbladder while only the 5(th), 10(th) and 15(th) measurement of gastric antral area were obtained. Gallbladder contraction indices were calculated and gastric emptying ratio obtained at the fifteenth minute is the indication of gastric motility. Statistical analyses were conducted using SPSS version 16.0 with p < 0.05 as criterion of statistical significance. RESULTS: The GBCIs followed Gaussian response at some stages and did not at some other stages. The least variability occurred at the 35th measurement of GBCI. A cut- off value for the 35th minute GBCI value was established with the mean ± 2 SD (80.79 ± 11.5%). Obvious gallbladder refilling was noted after 35 minutes. A positive relationship was noted between gallbladder and gastric motilities. CONCLUSION: With milk dilution, the variability of gall bladder motility is least at the 35th minute. A significant positive relationship between gastric emptying and gallbladder contraction index was also observed.

Assessment of the impact of background gamma radiation on reproductive defects in two major IGBO towns of Nigeria

Late biological effects of ionizing radiation on humans result in induction of cancers and various forms of genetic defects. A preliminary survey of hospital based data in Enugu and Owerri in the South Eastern States of Nigeria were carried out to ascertain possible relationship between our observed data on background radiation levels and reproductive abnormalities in these areas. The incidence of reproductive defects seems to correlate more with life style and socio-economic status than with background radiation dose rates