Linear scan computed tomography （LCT） is of great benefit to online industrial scanning and security inspection due to its characteristics of straight-line source trajectory and high scanning speed. However, in prac...Linear scan computed tomography （LCT） is of great benefit to online industrial scanning and security inspection due to its characteristics of straight-line source trajectory and high scanning speed. However, in practical applications of LCT, there are challenges to image reconstruction due to limited-angle and insufficient data. In this paper, a new reconstruction algorithm based on total-variation （TV） minimization is developed to reconstruct images from limited-angle and insufficient data in LCT. The main idea of our approach is to reformulate a TV problem as a linear equality constrained problem where the objective function is separable, and then minimize its augmented Lagrangian function by using alternating direction method （ADM） to solve subproblems. The proposed method is robust and efficient in the task of reconstruction by showing the convergence of ADM. The numerical simulations and real data reconstructions show that the proposed reconstruction method brings reasonable performance and outperforms some previous ones when applied to an LCT imaging problem.展开更多
Background: In Central African Republic, a study carried out in 2019 highlighted the limits of conventional radiography in the diagnosis of non-traumatic lower back pain in adults. Objective: The objective of this stu...Background: In Central African Republic, a study carried out in 2019 highlighted the limits of conventional radiography in the diagnosis of non-traumatic lower back pain in adults. Objective: The objective of this study is to show the value of CT scanning in the exploration of non-traumatic pathologies of the lumbar spine in adults. Patients and Method: Retrospective and descriptive cross-sectional study covering the files of patients aged at least 18 years old, sent for lumbar scanning from March 1 to December 31, 2021 at the medical imaging center. Results: In total, 593 scan examinations were performed including 159 (26.8%) examinations of the lumbar spine. The average age of the patients was 49.84 years. The majority were male (66%). 127 (79.8%) were referred mainly to the neurology and rheumatology departments. Common low back pain (n = 97, 61%) was the main reason for requesting a CT scan. The lumbar scan was performed without contrast product in 88.7% of cases. In total, 148 (93.1%) examinations were pathological and dominated by overall disc overhang (62.2%) and somatic and interapophyseal osteoarthritis (16.9%). The other lesions were spondylodiscitis (7.4%), tumor-like lesions (3.4%) and narrow lumbar canal (1.4%).展开更多
Background: Among medical technologies that use ionizing radiation, CT is currently the radio diagnostic technic that can deliver the highest radiation to the Patient compared with other conventional procedures. In de...Background: Among medical technologies that use ionizing radiation, CT is currently the radio diagnostic technic that can deliver the highest radiation to the Patient compared with other conventional procedures. In developing countries, the uses and risks of CT have not been well characterized. Objective: To estimate the lifetime attributable risk (LAR) incidence and mortality for cancer for each procedure for adult’s patients who had Computed Tomography examinations in 10 imaging centers in the city of Douala-Cameroon so as to provide a reference data. Materials and Methods: We conducted a cross-sectional study describing radiation dose associated with the 8 most common types of diagnostic CT studies performed on 1287 consecutive adult patients at 10 Douala radiology department. We estimated lifetime attributable risks of cancer by study type from these measured doses. Estimation of LAR for cancer incidence and mortality was based on the effective dose, patient’s sex and age at exposure using the BIER VII preferred models. Results: Mean effective dose from CT scans examinations varied from: 0.30 and 8.81 mSv. The highest doses were observed for lumbar spine CT (8.81 mSv), followed by abdomen-pelvis procedure (6.46 mSv), chest-abdomen-pelvic CT (6.61 mSv), chest CT (3.90 mSv), cervical Spine CT (3.05 mSv), head CT (1.7 mSv) and lower for sinus CT (0.30 mSv). The LAR values of all cancer from patients’ CT scans obtained vary from 67.13 excess per 100,000 (about 1 in 1489) and 0.45 excess per 100,000 (about 1 in 222,222). All cancer risk was high for lumbar spine CT in women 20 years old (67.13 excess deaths in 100,000 scans) followed by chest-abdomen-pelvic CT (50.36 excess deaths in 100,000 scans) and abdomen-pelvic CT (49.22 excess deaths in 100,000 scans) for the same age group. The LAR of incidence and mortality values were higher from female’s patients than males and higher for younger than older patients. Conclusion: This study was set out to estimate the LAR values associated with adult common CT scans procedures. The data indicates, LAR risks related to induced cancer from CT exposures were estimated to be low. This risk can be relatively significant for younger age group compared to older age group. The LAR values obtained will help to better evaluate radiation exposure risk, before ordering a CT scans examinations.展开更多
The aim of this case report is to raise awareness about the use of 3-Dimentional Computed Tomography (3D-CT) virtual reality imaging as a routine pre-operative tool for evaluation of unusual anatomy such as Situs Inve...The aim of this case report is to raise awareness about the use of 3-Dimentional Computed Tomography (3D-CT) virtual reality imaging as a routine pre-operative tool for evaluation of unusual anatomy such as Situs Inversus Totalis (SIT). We present a case of presumed lung cancer in a 58 years old lady with SIT successfully treated by VATS lobectomy via an anterior approach. She presented with an incidental solitary pulmonary nodule in her right lower lobe, which had moderate FDG uptake on the PET scan. The nodule was too deep to permit safe wedge biopsy, due to proximity of a large pulmonary arterial branch. 3D-CT images were invaluable in pre-operative assessment of the anatomy and were the key to safe completion of right VATS lower lobectomy. Sectioning the lung after retrieval of the specimen suggested a chondroid hamartoma;therefore, systemic nodal dissection (SND) was not contemplated. The final histology confirmed the diagnosis of chondroid hamartoma. In an unusual anatomy such as SIT, 3D-CT allows construction of virtual reality models that can be viewed and manipulated before and during the operation to understand the anatomy better, highlight caveats around target structures and enable localisation of lesions unlikely to be palpated intra-operatively.展开更多
Background: Brain malformations (BMs) are congenital abnormalities of the shape or structure of the brain, with corpus callosum agenesis known as the most frequent. Diagnosis of most BMs can be prenatal with ultrasoun...Background: Brain malformations (BMs) are congenital abnormalities of the shape or structure of the brain, with corpus callosum agenesis known as the most frequent. Diagnosis of most BMs can be prenatal with ultrasound and fetal magnetic resonance imaging (MRI);post-natal diagnosis is based on transfontanellar ultrasound, CT-scan, and head MRI which is the imaging gold standard technique. MRI has been recently introduced and the CT-scan was previously the reference technique for the diagnosis of BMs in our context. Almost no publication has been made in sub-Saharan Africa on the clinical and CT scan characteristics of Brain malformations in children. Objective: The aim of this study was, in the absence of MRI, to describe the clinical and CT-scan presentations of brain malformations in children at the Yaounde Gynaeco-Obstetric and Pediatric Hospital (YGOPH). Patients and method: This was a cross-sectional descriptive study conducted from February to May 2016 at the YGOPH, including all children of 15-year-old and less with BM diagnosed on CT-scan at YGOPH between April 2006 and March 2016. The studied variables were clinical (age at diagnosis, sex, clinical manifestations) and CT findings (type of cerebral malformation). The data was analyzed using the SPSS 20.0 software with the estimation of hospital prevalence of BMs, frequencies and associations. The chi-square test was used to seek for an association between variables. The threshold of significance was p Results: The prevalence of BMs was 0.52%, with 29 cases of BMs identified out of 5590 patients followed up at the pediatric neurology outpatient unit over a period of 10 years. The mean age at diagnosis was 37.2 months (3.1 years) and the most represented age groups were 0 - 1 year (37.9%) and 1 - 5 years (37.9%). The sex ratio was 0.81 (55.2% girls). The clinical presentation was represented by neurological signs (93.1%) with convulsions (65.5%) and psychomotor retardation (58.8%) associated with skin lesions (34.5%) and/or facial dysmorphic features (27.6%). BM was suspected on antenatal ultrasound in 14.3% of cases (4/28). Abnormalities of cortical development accounted for 65.5% of BM followed by abnormalities of brain separation (31%). Tuberous sclerosis complex was the most common BM (31%) followed by agenesis of the corpus callosum (27.6%). The presence of dysmorphic facial features was associated (p = 0.007) with disorders of brain separation (DBS) while the presence of cutaneous lesions was associated (p = 0.013) with anomalies of the cortical development (ACD) especially tuberous sclerosis complex. Conclusion: BMs are infrequent, dominated by tuberous sclerosis complex and agenesis of the corpus callosum. They are mainly revealed by convulsions and psychomotor retardation. Efforts are needed to improve antenatal diagnosis and facilitate access to cerebral MRI.展开更多
Hemangioblastomas are benign vascular tumors of the brain. These are rare tumors, usually located in the cerebellum and most often affecting young adults. The aim was to study the value of CT in the management of hema...Hemangioblastomas are benign vascular tumors of the brain. These are rare tumors, usually located in the cerebellum and most often affecting young adults. The aim was to study the value of CT in the management of hemangioblastoma through observation. We report the case of a 38-year-old patient referred to the radiology and Medical Imaging Department of the Marie Curie Medical Clinic in Bamako, Mali, for an orbito-cerebral CT scan in a context of bilateral eyelid edema. The examination was performed using multi-slice computed tomography (16 slices) with reconstruction in the 3 planes of space without and with the injection of an iodinated contrast agent. The CT scan was crucial in making the diagnosis of hemangioblastoma incidentally, which allowed for adequate management. The patient was operated on, and the radiological outcome was favorable, without significant cystic formation, after postoperative control and clinical signs were resolved. CT can be an interesting alternative in countries like ours despite MRI being the examination of choice in hemangioblastomas.展开更多
Objective: This study aimed to describe anatomic variants of sphenoidal sinuses and adjacent structures. Methods: A retrospective and descriptive study was carried out at The National and University Teaching Hospital ...Objective: This study aimed to describe anatomic variants of sphenoidal sinuses and adjacent structures. Methods: A retrospective and descriptive study was carried out at The National and University Teaching Hospital Hubert Koutoukou Maga (CNHU-HKM), of Cotonou in Benin from November 1st to December 31st. A review of CT scans skull was done for the subjects aged at least 16 years old. Anatomic variants of the sphenoid sinuses and adjacent structures have been investigated. Results: 225 CT scans of skull were analyzed. The sellar type was the most common type of pneumatization of sphenoid sinuses (74.7%). Pneumatization of anterior clinoid processes of greater and lesser wings of the sphenoid and of pterygoid processes was observed in 7.1%;4.6%;3.3% and 7.3%;respectively. Protrusion of carotid canals and optic canals, maxillary and vidian nerves were observed in 48.3%;13.1%;18% and 9.5%;respectively. Conclusion: Risky anatomic variants of the sphenoid sinuses and adjacent structures are also described by CT-scan among Beninese. Before any surgery and to avoid bad outcome, a precise approach of these risky anatomic variants must be carried out by using CT-scan.展开更多
Objective: To evaluate the lung CT scan as a possible predictive diagnostic method for COVID-19 in the Cameroonian context. Methods: We designed a cross sectional study. Suspected cases of COVID-19 during the first wa...Objective: To evaluate the lung CT scan as a possible predictive diagnostic method for COVID-19 in the Cameroonian context. Methods: We designed a cross sectional study. Suspected cases of COVID-19 during the first wave at the national social insurance fund (NSIF) hospital were screened with both COVID-19 with lung CT scan and a PCR test. Univariate analysis was performed for sample description and multivariate analysis to assess the correlation between positive results for the PCR and other parameters. We estimated the optimum threshold of sensitivity/specificity, and area under curve using the empirical method and package. Results: A total of 62 suspected COVID-19 cases were recorded, predominantly males (Sex Ratio = 2.2) with a median age of 58.5 (IQR = 19.7). Among our 62 patients, 29 (46.8%) were confirmed COVID-19 cases with positive PCR results. All the patients had a thorax CT scan with a median impairment of 40% (IQR = 20%). The optimum threshold estimate for CT scan for COVID-19 infection diagnosis was 60% (95% CI = 25% - 80%). Overall, the sensitivity and specificity estimates were 0.30 (95% CI = 0.15 - 0.49) and 0.87 (95% CI = 0.70 - 0.96), respectively, leading to an Area Under Curve (AUC) estimate of 0.59 (95% CI = 0.46, 0.71). Conclusion: In this setting, lung CT scan was neither sensitive nor specific to predict COVID-19 disease.展开更多
Technologies that measure activation of components of the DNA damage response (DDR) have applications in exposure assessment and personalized medicine. The DDR and associated DNA repair pathways encompass hundreds of ...Technologies that measure activation of components of the DNA damage response (DDR) have applications in exposure assessment and personalized medicine. The DDR and associated DNA repair pathways encompass hundreds of proteins, making detailed measurement of activation technically challenging and laborious. The purpose of our study was to develop protein-specific assays for certain DDR components on a high-throughput electrochemiluminescence (ECL)-based platform. We developed five working assay pairs for ataxia telangiectasia mutated (ATM), checkpoint kinase 2 (CHK2), phosphorylated-ATM S1981, phosphorylated-CHK2 T68 and phosphorylated-tumor protein p53 (p53) S15. We validated the ECL results against traditional immunoblot and γ-H2AX foci measures in cell and cancer models. In an effort to test the ECL-based technology in a clinical setting, we utilized peripheral blood mononuclear cells (PBMCs) from patients undergoing computed tomography (CT) scans. CT scans represent both a valuable medical imaging diagnostic and a controlled environmental exposure to ionizing radiation for research studies, as they deliver ~2 to 31 millisieverts (mSv) and are known to activate DDR components. In this study, we show that ECL-based technology can measure the basal and damage-induced levels of DDR components in patient PBMC samples. Using a blinded study design and patient matched pre- and post CT scan samples, we show that ECL-derived data can consistently (94% of the time, 15/16 patients) identify PBMCs that have been exposed to low dose ionizing radiation associated with CT scans. Ultimately, the results of our pilot clinical study support the idea that ECL-based technology is applicable for use in clinical and population cohorts that study components of the DDR.展开更多
Brain malformations are rare, difficult to diagnose and have unpredictable evolution. They are the major causes of epilepsy, psychomotor development abnormalities and other neurological disorders. The neuroimaging tec...Brain malformations are rare, difficult to diagnose and have unpredictable evolution. They are the major causes of epilepsy, psychomotor development abnormalities and other neurological disorders. The neuroimaging technique of choice for diagnosis of these malformations is magnetic resonance imaging (MRI), but unfortunately MRI is expensive, and is not available in a poor resource country like Cameroon. CT scan associated to clinical signs can help to suspect or to confirm a malformation. The authors report here three cases of malformations discovered during cranial CT scan at the regional hospital of Ngaoundéré. They are Dandy Walker malformation, Sturge Weber’s disease and hemimegalencephaly. These cases contribute to the knowledge of this rare event, and emphasize the importance of CT scan on their diagnosis in the absence of MRI.展开更多
Background: Detection of malignant liver mass is very important for the treatment modalities. Objective: The purpose of the present study was to establish the usefulness of CT scan in the diagnosis of malignant hepati...Background: Detection of malignant liver mass is very important for the treatment modalities. Objective: The purpose of the present study was to establish the usefulness of CT scan in the diagnosis of malignant hepatic mass. Methodology: This cross sectional study was carried out in the Department of Radiology and Imaging at Mymensingh Medical College Hospital (MMCH), Mymensingh, Banghabandhu Sheikh Mujib Medical University (BSMMU), Dhaka and Dhaka Medical College Hospital (DMCH), Dhaka during the period of 1st January 2006 to 31st December 2007. Patients admitted in the Department of Medicine and Department of Hepatobiliary of MMCH, BSMMU, and DMCH with the clinical diagnosis of fever, abdominal pain, anorexia, nausea/vomiting, loss of appetite, jaundice, weight loss and ascites were selected as study population. CT scan and histopathology were performed to all the patients. Result: A total number of 50 patients were recruited for this study. Mean age of all patients was 51.28 ± 14 years with a range of 17 year to 78 years. Among all patients 28 had multiple lesion, of them 71.4% was malignant and 28.6% was benign. On the other side 22 patients had solitary lesion, of them 36.4% was malignant and 63.6% was benign展开更多
Purpose: Despite irradiation, CT-scan remains an important diagnostic tool in epilepsy in poor countries where MRI is neither available nor affordable. But many causes of epilepsy are not accessible to CT-scan and thi...Purpose: Despite irradiation, CT-scan remains an important diagnostic tool in epilepsy in poor countries where MRI is neither available nor affordable. But many causes of epilepsy are not accessible to CT-scan and this technique remains expensive for many poor families in countries with limited resources. The aim of this study was to determine clinical or electroencephalogram variables which could predict brain CT-scan abnormalities in childhood epilepsy. Methods: It was a cross-sectional study including 151 epileptic children who underwent head CT-scan from October 2011 to march 2012, in one university-affiliated hospital in Cameroon (YGOPH). The data collected were clinical, type of seizure, Electroencephalogram and head CT-scans results. Independent predictive factors for CT abnormalities were sought by logistic regression. A p value : Of the 151 children, 54.3% (82/151) were boys (sex ratio: 1.18 M/1F). The median age was 54 months [2 - 190 months];74.8% of children were more than 2 years old but at the onset of epilepsy they were 2 years old or less. Birth asphyxia, mental retardation and neurologic deficit were respectively associated in 62.4%, 54.3% and 51.7% of cases. Eighty-five had focal epilepsy (56.3%), 61.6% had abnormal head CT-scan, 68.9% had abnormal EEG, with no significant gender difference. The factors most significantly associated with abnormal head CT-scan were: child age ≤ 2 years, maternal hypertension/eclampsy, cerebral palsy, and child microcephaly, with 89% to 92% abnormal CT. The two independent predictors of abnormal CT were patients’ age ≤ 2 years and microcephaly. The two main CT-scan lesions were cerebral atrophy (28.5%) and brain infarct (16.6%). None of these abnormalities was correlated to any type of epilepsy. Conclusion: Almost two-thirds of head CT-scan performed in epileptic children are abnormal in our setting. Patients of 2 years old or less and those with microcephaly are very likely to have brain anomalies on CT-scan. The most common brain lesions are atrophy, cerebral infarction and porencephalic cavities. Action to reduce birth asphyxia may lead to the reduction of the incidence of epilepsy in children.展开更多
Background: CT-scan is a very useful diagnostic tool for the detection of hepatic mass. Objective: The present study was undertaken to determine the CT-scan findings of benign and malignant hepatic mass patients. Meth...Background: CT-scan is a very useful diagnostic tool for the detection of hepatic mass. Objective: The present study was undertaken to determine the CT-scan findings of benign and malignant hepatic mass patients. Methodology: This was a cross sectional study conducted in Radiology and Imaging Department at Mymensingh Medical College Hospital (MMCH), Mymensingh;Dhaka Medical College Hospital (DMCH), Dhaka and Banghabandhu Sheikh Mujib Medical University (BSMMU), Dhaka with the collaboration of Pathology Department of the same institute for histopathological confirmation. This study was carried out from January 2006 to December 2007 for a period of 2 years. The patients who were clinically suspected of having hepatic mass attended in the Radiology and Imaging Department in the above mentioned institutes were included as study population. All the CT-scan findings were recorded. Result: A total number of 50 patients were enrolled for this study. CT-scan was done among 40 males and 10 females with a mean age of 51.28 years old. Hypodensity was found in 17 (60.7%) and 18 (81.8%) cases in malignant and benign hepatic lesions respectively. Ill-defined margin was detected in 12 (42.9%) and 6 (27.3%) cases respectively. Calcification was present on 11 (39.3%) malignant lesion and 6 (27.3%) benign lesions. Pressure effect on biliary apparatus was found in 11 (39.3%) malignant lesions and 1 (4.5%) benign lesions (p < 0.05). Lymphadenopathy was found in 10 (35.7%) malignant lesions and 1 (4.5%) benign lesions (p < 0.05). Conclusion: In conclusion, CT-scan findings of malignant and benign hepatic mass show hypodensity with more contrast enhancement in malignant lesions with more calcification in malignant lesion;however, significant difference is detected in pressure effect on biliary apparatus and lymphadenopathy.展开更多
基金the National High Technology Research and Development Program of China(Grant No.2012AA011603)
文摘Linear scan computed tomography （LCT） is of great benefit to online industrial scanning and security inspection due to its characteristics of straight-line source trajectory and high scanning speed. However, in practical applications of LCT, there are challenges to image reconstruction due to limited-angle and insufficient data. In this paper, a new reconstruction algorithm based on total-variation （TV） minimization is developed to reconstruct images from limited-angle and insufficient data in LCT. The main idea of our approach is to reformulate a TV problem as a linear equality constrained problem where the objective function is separable, and then minimize its augmented Lagrangian function by using alternating direction method （ADM） to solve subproblems. The proposed method is robust and efficient in the task of reconstruction by showing the convergence of ADM. The numerical simulations and real data reconstructions show that the proposed reconstruction method brings reasonable performance and outperforms some previous ones when applied to an LCT imaging problem.
文摘Background: In Central African Republic, a study carried out in 2019 highlighted the limits of conventional radiography in the diagnosis of non-traumatic lower back pain in adults. Objective: The objective of this study is to show the value of CT scanning in the exploration of non-traumatic pathologies of the lumbar spine in adults. Patients and Method: Retrospective and descriptive cross-sectional study covering the files of patients aged at least 18 years old, sent for lumbar scanning from March 1 to December 31, 2021 at the medical imaging center. Results: In total, 593 scan examinations were performed including 159 (26.8%) examinations of the lumbar spine. The average age of the patients was 49.84 years. The majority were male (66%). 127 (79.8%) were referred mainly to the neurology and rheumatology departments. Common low back pain (n = 97, 61%) was the main reason for requesting a CT scan. The lumbar scan was performed without contrast product in 88.7% of cases. In total, 148 (93.1%) examinations were pathological and dominated by overall disc overhang (62.2%) and somatic and interapophyseal osteoarthritis (16.9%). The other lesions were spondylodiscitis (7.4%), tumor-like lesions (3.4%) and narrow lumbar canal (1.4%).
文摘Background: Among medical technologies that use ionizing radiation, CT is currently the radio diagnostic technic that can deliver the highest radiation to the Patient compared with other conventional procedures. In developing countries, the uses and risks of CT have not been well characterized. Objective: To estimate the lifetime attributable risk (LAR) incidence and mortality for cancer for each procedure for adult’s patients who had Computed Tomography examinations in 10 imaging centers in the city of Douala-Cameroon so as to provide a reference data. Materials and Methods: We conducted a cross-sectional study describing radiation dose associated with the 8 most common types of diagnostic CT studies performed on 1287 consecutive adult patients at 10 Douala radiology department. We estimated lifetime attributable risks of cancer by study type from these measured doses. Estimation of LAR for cancer incidence and mortality was based on the effective dose, patient’s sex and age at exposure using the BIER VII preferred models. Results: Mean effective dose from CT scans examinations varied from: 0.30 and 8.81 mSv. The highest doses were observed for lumbar spine CT (8.81 mSv), followed by abdomen-pelvis procedure (6.46 mSv), chest-abdomen-pelvic CT (6.61 mSv), chest CT (3.90 mSv), cervical Spine CT (3.05 mSv), head CT (1.7 mSv) and lower for sinus CT (0.30 mSv). The LAR values of all cancer from patients’ CT scans obtained vary from 67.13 excess per 100,000 (about 1 in 1489) and 0.45 excess per 100,000 (about 1 in 222,222). All cancer risk was high for lumbar spine CT in women 20 years old (67.13 excess deaths in 100,000 scans) followed by chest-abdomen-pelvic CT (50.36 excess deaths in 100,000 scans) and abdomen-pelvic CT (49.22 excess deaths in 100,000 scans) for the same age group. The LAR of incidence and mortality values were higher from female’s patients than males and higher for younger than older patients. Conclusion: This study was set out to estimate the LAR values associated with adult common CT scans procedures. The data indicates, LAR risks related to induced cancer from CT exposures were estimated to be low. This risk can be relatively significant for younger age group compared to older age group. The LAR values obtained will help to better evaluate radiation exposure risk, before ordering a CT scans examinations.
文摘The aim of this case report is to raise awareness about the use of 3-Dimentional Computed Tomography (3D-CT) virtual reality imaging as a routine pre-operative tool for evaluation of unusual anatomy such as Situs Inversus Totalis (SIT). We present a case of presumed lung cancer in a 58 years old lady with SIT successfully treated by VATS lobectomy via an anterior approach. She presented with an incidental solitary pulmonary nodule in her right lower lobe, which had moderate FDG uptake on the PET scan. The nodule was too deep to permit safe wedge biopsy, due to proximity of a large pulmonary arterial branch. 3D-CT images were invaluable in pre-operative assessment of the anatomy and were the key to safe completion of right VATS lower lobectomy. Sectioning the lung after retrieval of the specimen suggested a chondroid hamartoma;therefore, systemic nodal dissection (SND) was not contemplated. The final histology confirmed the diagnosis of chondroid hamartoma. In an unusual anatomy such as SIT, 3D-CT allows construction of virtual reality models that can be viewed and manipulated before and during the operation to understand the anatomy better, highlight caveats around target structures and enable localisation of lesions unlikely to be palpated intra-operatively.
文摘Background: Brain malformations (BMs) are congenital abnormalities of the shape or structure of the brain, with corpus callosum agenesis known as the most frequent. Diagnosis of most BMs can be prenatal with ultrasound and fetal magnetic resonance imaging (MRI);post-natal diagnosis is based on transfontanellar ultrasound, CT-scan, and head MRI which is the imaging gold standard technique. MRI has been recently introduced and the CT-scan was previously the reference technique for the diagnosis of BMs in our context. Almost no publication has been made in sub-Saharan Africa on the clinical and CT scan characteristics of Brain malformations in children. Objective: The aim of this study was, in the absence of MRI, to describe the clinical and CT-scan presentations of brain malformations in children at the Yaounde Gynaeco-Obstetric and Pediatric Hospital (YGOPH). Patients and method: This was a cross-sectional descriptive study conducted from February to May 2016 at the YGOPH, including all children of 15-year-old and less with BM diagnosed on CT-scan at YGOPH between April 2006 and March 2016. The studied variables were clinical (age at diagnosis, sex, clinical manifestations) and CT findings (type of cerebral malformation). The data was analyzed using the SPSS 20.0 software with the estimation of hospital prevalence of BMs, frequencies and associations. The chi-square test was used to seek for an association between variables. The threshold of significance was p Results: The prevalence of BMs was 0.52%, with 29 cases of BMs identified out of 5590 patients followed up at the pediatric neurology outpatient unit over a period of 10 years. The mean age at diagnosis was 37.2 months (3.1 years) and the most represented age groups were 0 - 1 year (37.9%) and 1 - 5 years (37.9%). The sex ratio was 0.81 (55.2% girls). The clinical presentation was represented by neurological signs (93.1%) with convulsions (65.5%) and psychomotor retardation (58.8%) associated with skin lesions (34.5%) and/or facial dysmorphic features (27.6%). BM was suspected on antenatal ultrasound in 14.3% of cases (4/28). Abnormalities of cortical development accounted for 65.5% of BM followed by abnormalities of brain separation (31%). Tuberous sclerosis complex was the most common BM (31%) followed by agenesis of the corpus callosum (27.6%). The presence of dysmorphic facial features was associated (p = 0.007) with disorders of brain separation (DBS) while the presence of cutaneous lesions was associated (p = 0.013) with anomalies of the cortical development (ACD) especially tuberous sclerosis complex. Conclusion: BMs are infrequent, dominated by tuberous sclerosis complex and agenesis of the corpus callosum. They are mainly revealed by convulsions and psychomotor retardation. Efforts are needed to improve antenatal diagnosis and facilitate access to cerebral MRI.
文摘Hemangioblastomas are benign vascular tumors of the brain. These are rare tumors, usually located in the cerebellum and most often affecting young adults. The aim was to study the value of CT in the management of hemangioblastoma through observation. We report the case of a 38-year-old patient referred to the radiology and Medical Imaging Department of the Marie Curie Medical Clinic in Bamako, Mali, for an orbito-cerebral CT scan in a context of bilateral eyelid edema. The examination was performed using multi-slice computed tomography (16 slices) with reconstruction in the 3 planes of space without and with the injection of an iodinated contrast agent. The CT scan was crucial in making the diagnosis of hemangioblastoma incidentally, which allowed for adequate management. The patient was operated on, and the radiological outcome was favorable, without significant cystic formation, after postoperative control and clinical signs were resolved. CT can be an interesting alternative in countries like ours despite MRI being the examination of choice in hemangioblastomas.
文摘Objective: This study aimed to describe anatomic variants of sphenoidal sinuses and adjacent structures. Methods: A retrospective and descriptive study was carried out at The National and University Teaching Hospital Hubert Koutoukou Maga (CNHU-HKM), of Cotonou in Benin from November 1st to December 31st. A review of CT scans skull was done for the subjects aged at least 16 years old. Anatomic variants of the sphenoid sinuses and adjacent structures have been investigated. Results: 225 CT scans of skull were analyzed. The sellar type was the most common type of pneumatization of sphenoid sinuses (74.7%). Pneumatization of anterior clinoid processes of greater and lesser wings of the sphenoid and of pterygoid processes was observed in 7.1%;4.6%;3.3% and 7.3%;respectively. Protrusion of carotid canals and optic canals, maxillary and vidian nerves were observed in 48.3%;13.1%;18% and 9.5%;respectively. Conclusion: Risky anatomic variants of the sphenoid sinuses and adjacent structures are also described by CT-scan among Beninese. Before any surgery and to avoid bad outcome, a precise approach of these risky anatomic variants must be carried out by using CT-scan.
文摘Objective: To evaluate the lung CT scan as a possible predictive diagnostic method for COVID-19 in the Cameroonian context. Methods: We designed a cross sectional study. Suspected cases of COVID-19 during the first wave at the national social insurance fund (NSIF) hospital were screened with both COVID-19 with lung CT scan and a PCR test. Univariate analysis was performed for sample description and multivariate analysis to assess the correlation between positive results for the PCR and other parameters. We estimated the optimum threshold of sensitivity/specificity, and area under curve using the empirical method and package. Results: A total of 62 suspected COVID-19 cases were recorded, predominantly males (Sex Ratio = 2.2) with a median age of 58.5 (IQR = 19.7). Among our 62 patients, 29 (46.8%) were confirmed COVID-19 cases with positive PCR results. All the patients had a thorax CT scan with a median impairment of 40% (IQR = 20%). The optimum threshold estimate for CT scan for COVID-19 infection diagnosis was 60% (95% CI = 25% - 80%). Overall, the sensitivity and specificity estimates were 0.30 (95% CI = 0.15 - 0.49) and 0.87 (95% CI = 0.70 - 0.96), respectively, leading to an Area Under Curve (AUC) estimate of 0.59 (95% CI = 0.46, 0.71). Conclusion: In this setting, lung CT scan was neither sensitive nor specific to predict COVID-19 disease.
文摘Technologies that measure activation of components of the DNA damage response (DDR) have applications in exposure assessment and personalized medicine. The DDR and associated DNA repair pathways encompass hundreds of proteins, making detailed measurement of activation technically challenging and laborious. The purpose of our study was to develop protein-specific assays for certain DDR components on a high-throughput electrochemiluminescence (ECL)-based platform. We developed five working assay pairs for ataxia telangiectasia mutated (ATM), checkpoint kinase 2 (CHK2), phosphorylated-ATM S1981, phosphorylated-CHK2 T68 and phosphorylated-tumor protein p53 (p53) S15. We validated the ECL results against traditional immunoblot and γ-H2AX foci measures in cell and cancer models. In an effort to test the ECL-based technology in a clinical setting, we utilized peripheral blood mononuclear cells (PBMCs) from patients undergoing computed tomography (CT) scans. CT scans represent both a valuable medical imaging diagnostic and a controlled environmental exposure to ionizing radiation for research studies, as they deliver ~2 to 31 millisieverts (mSv) and are known to activate DDR components. In this study, we show that ECL-based technology can measure the basal and damage-induced levels of DDR components in patient PBMC samples. Using a blinded study design and patient matched pre- and post CT scan samples, we show that ECL-derived data can consistently (94% of the time, 15/16 patients) identify PBMCs that have been exposed to low dose ionizing radiation associated with CT scans. Ultimately, the results of our pilot clinical study support the idea that ECL-based technology is applicable for use in clinical and population cohorts that study components of the DDR.
文摘Brain malformations are rare, difficult to diagnose and have unpredictable evolution. They are the major causes of epilepsy, psychomotor development abnormalities and other neurological disorders. The neuroimaging technique of choice for diagnosis of these malformations is magnetic resonance imaging (MRI), but unfortunately MRI is expensive, and is not available in a poor resource country like Cameroon. CT scan associated to clinical signs can help to suspect or to confirm a malformation. The authors report here three cases of malformations discovered during cranial CT scan at the regional hospital of Ngaoundéré. They are Dandy Walker malformation, Sturge Weber’s disease and hemimegalencephaly. These cases contribute to the knowledge of this rare event, and emphasize the importance of CT scan on their diagnosis in the absence of MRI.
文摘Background: Detection of malignant liver mass is very important for the treatment modalities. Objective: The purpose of the present study was to establish the usefulness of CT scan in the diagnosis of malignant hepatic mass. Methodology: This cross sectional study was carried out in the Department of Radiology and Imaging at Mymensingh Medical College Hospital (MMCH), Mymensingh, Banghabandhu Sheikh Mujib Medical University (BSMMU), Dhaka and Dhaka Medical College Hospital (DMCH), Dhaka during the period of 1st January 2006 to 31st December 2007. Patients admitted in the Department of Medicine and Department of Hepatobiliary of MMCH, BSMMU, and DMCH with the clinical diagnosis of fever, abdominal pain, anorexia, nausea/vomiting, loss of appetite, jaundice, weight loss and ascites were selected as study population. CT scan and histopathology were performed to all the patients. Result: A total number of 50 patients were recruited for this study. Mean age of all patients was 51.28 ± 14 years with a range of 17 year to 78 years. Among all patients 28 had multiple lesion, of them 71.4% was malignant and 28.6% was benign. On the other side 22 patients had solitary lesion, of them 36.4% was malignant and 63.6% was benign
文摘Purpose: Despite irradiation, CT-scan remains an important diagnostic tool in epilepsy in poor countries where MRI is neither available nor affordable. But many causes of epilepsy are not accessible to CT-scan and this technique remains expensive for many poor families in countries with limited resources. The aim of this study was to determine clinical or electroencephalogram variables which could predict brain CT-scan abnormalities in childhood epilepsy. Methods: It was a cross-sectional study including 151 epileptic children who underwent head CT-scan from October 2011 to march 2012, in one university-affiliated hospital in Cameroon (YGOPH). The data collected were clinical, type of seizure, Electroencephalogram and head CT-scans results. Independent predictive factors for CT abnormalities were sought by logistic regression. A p value : Of the 151 children, 54.3% (82/151) were boys (sex ratio: 1.18 M/1F). The median age was 54 months [2 - 190 months];74.8% of children were more than 2 years old but at the onset of epilepsy they were 2 years old or less. Birth asphyxia, mental retardation and neurologic deficit were respectively associated in 62.4%, 54.3% and 51.7% of cases. Eighty-five had focal epilepsy (56.3%), 61.6% had abnormal head CT-scan, 68.9% had abnormal EEG, with no significant gender difference. The factors most significantly associated with abnormal head CT-scan were: child age ≤ 2 years, maternal hypertension/eclampsy, cerebral palsy, and child microcephaly, with 89% to 92% abnormal CT. The two independent predictors of abnormal CT were patients’ age ≤ 2 years and microcephaly. The two main CT-scan lesions were cerebral atrophy (28.5%) and brain infarct (16.6%). None of these abnormalities was correlated to any type of epilepsy. Conclusion: Almost two-thirds of head CT-scan performed in epileptic children are abnormal in our setting. Patients of 2 years old or less and those with microcephaly are very likely to have brain anomalies on CT-scan. The most common brain lesions are atrophy, cerebral infarction and porencephalic cavities. Action to reduce birth asphyxia may lead to the reduction of the incidence of epilepsy in children.
文摘Background: CT-scan is a very useful diagnostic tool for the detection of hepatic mass. Objective: The present study was undertaken to determine the CT-scan findings of benign and malignant hepatic mass patients. Methodology: This was a cross sectional study conducted in Radiology and Imaging Department at Mymensingh Medical College Hospital (MMCH), Mymensingh;Dhaka Medical College Hospital (DMCH), Dhaka and Banghabandhu Sheikh Mujib Medical University (BSMMU), Dhaka with the collaboration of Pathology Department of the same institute for histopathological confirmation. This study was carried out from January 2006 to December 2007 for a period of 2 years. The patients who were clinically suspected of having hepatic mass attended in the Radiology and Imaging Department in the above mentioned institutes were included as study population. All the CT-scan findings were recorded. Result: A total number of 50 patients were enrolled for this study. CT-scan was done among 40 males and 10 females with a mean age of 51.28 years old. Hypodensity was found in 17 (60.7%) and 18 (81.8%) cases in malignant and benign hepatic lesions respectively. Ill-defined margin was detected in 12 (42.9%) and 6 (27.3%) cases respectively. Calcification was present on 11 (39.3%) malignant lesion and 6 (27.3%) benign lesions. Pressure effect on biliary apparatus was found in 11 (39.3%) malignant lesions and 1 (4.5%) benign lesions (p < 0.05). Lymphadenopathy was found in 10 (35.7%) malignant lesions and 1 (4.5%) benign lesions (p < 0.05). Conclusion: In conclusion, CT-scan findings of malignant and benign hepatic mass show hypodensity with more contrast enhancement in malignant lesions with more calcification in malignant lesion;however, significant difference is detected in pressure effect on biliary apparatus and lymphadenopathy.
