Introduction: MRI is a rapidly growing technique with more and more indica-tions and requests in the Republic of Guinea. Its correct prescription is a guar-antee for the satisfaction of the actors, both prescribers, r...Introduction: MRI is a rapidly growing technique with more and more indica-tions and requests in the Republic of Guinea. Its correct prescription is a guar-antee for the satisfaction of the actors, both prescribers, radiologists and pa-tients. The main objective of this study was to evaluate the compliance of MRI examination requests at the Diagnostic Center of the National Social Se-curity Fund (CNSS) in Conakry. Material and Methods: This was a descriptive cross-sectional study of MRI prescription forms sent to the MRI unit of the CNSS Diagnostic Center from February 1 to May 1, 2021. The 8 compliance criteria established by the French High Authority for Health were used to evaluate the compliance of the examination requests. Results: A total of 7003 examination forms were sent to the facility, including 7% (n = 468) of MRIs. 56.2% of MRI requests were performed by specialists. We observed an overall compliance of 10%. Administrative and clinical compliance were missing in 24% and 38%, respectively. More specifically, the purpose of the examination was not mentioned in 60%, followed by the requesting department in 48.1% and the patient’s age in 35.1%. Conclusion: This study allowed us to highlight the gaps in establishing MRI requests. It would be important to organize an awareness campaign for prescribers on the usefulness of correctly filling an MRI request and to design templates to be filled out by prescribers.展开更多
Breast pathology is varied, bringing together tumor and non-tumor lesions. Objective: To study the contribution of the ultrasound-mammography pair in the diagnosis of breast pathologies. Materials and Method: This was...Breast pathology is varied, bringing together tumor and non-tumor lesions. Objective: To study the contribution of the ultrasound-mammography pair in the diagnosis of breast pathologies. Materials and Method: This was a retrospective descriptive study, carried out over a period of 3 years (from January 2018 to December 2020) at the Diagnostic Imaging Center (C.I.D) “TERIYA” in BAMAKO. It concerned all patients who came for a mammogram/ultrasound examination of the breast. All women admitted for mammogram or breast ultrasound who were diagnosed with a breast injury during the study period were included. Incomplete records and radiological checks were not included. The variables analyzed were age, sex, clinical data, and ultrasound and mammography aspects. The devices used are: a Voluson 730 PRO ultrasound machine and a G 600T type mammography machine. Results: At the end of our study, we collected 254 breast pathologies on a number of 382 women, i.e. a frequency of 66.49%. The average age of our patients was 41 years old. The dominant clinical data were mastodynia (41.88%) and mammary nodule (21.70%). On imaging (mammo-ultrasound) the lesions predominated on the left in 36% of cases, bilateral in 28% of cases and in the upper-outer quadrants in 31.5% of cases. Tumor pathologies represented 66.54% of which 45.27% were benign mainly composed of fibro-adenoma (20.88%) and cyst (18.50%), 11.8% of suspected cases and 9.45% of cancers. Non-tumor pathologies represented 33.46%, mainly mastitis (16.14%), galactophoric dilations (11.02%) and abscesses (5.51%). These pathologies were classified in 50.3% in ACR2, 17.75% in ACR3 and 4, and in 14.20% in ACR5. Lymphadenopathy was present in 73.21% of cases.展开更多
Cerebral small vessel disease is a neurological disease that affects the brain microvasculature and which is commonly observed among the elderly.Although at first it was considered innocuous,small vessel disease is no...Cerebral small vessel disease is a neurological disease that affects the brain microvasculature and which is commonly observed among the elderly.Although at first it was considered innocuous,small vessel disease is nowadays regarded as one of the major vascular causes of dementia.Radiological signs of small vessel disease include small subcortical infarcts,white matter magnetic resonance imaging hyperintensities,lacunes,enlarged perivascular spaces,cerebral microbleeds,and brain atrophy;however,great heterogeneity in clinical symptoms is observed in small vessel disease patients.The pathophysiology of these lesions has been linked to multiple processes,such as hypoperfusion,defective cerebrovascular reactivity,and blood-brain barrier dysfunction.Notably,studies on small vessel disease suggest that blood-brain barrier dysfunction is among the earliest mechanisms in small vessel disease and might contribute to the development of the hallmarks of small vessel disease.Therefore,the purpose of this review is to provide a new foundation in the study of small vessel disease pathology.First,we discuss the main structural domains and functions of the blood-brain barrier.Secondly,we review the most recent evidence on blood-brain barrier dysfunction linked to small vessel disease.Finally,we conclude with a discussion on future perspectives and propose potential treatment targets and interventions.展开更多
Ambroxol hydrochloride(2-amino-3,5-dibromo-N-methylbenzylamine hydrochloride)has been used as a mucolytic agent in the treatment of respiratory diseases since the late 1970s.Its effects on mucus membranes such as mucu...Ambroxol hydrochloride(2-amino-3,5-dibromo-N-methylbenzylamine hydrochloride)has been used as a mucolytic agent in the treatment of respiratory diseases since the late 1970s.Its effects on mucus membranes such as mucus disruption,increased mucus production,and low toxicity profile were addressed in its original German patent in 1966.These first described properties have kept Ambroxol available worldwide and over the counter in the pharmaceutical market to this day.展开更多
BACKGROUND Patients with Parkinson’s disease(PD)often experience depression,and some may require magnetic resonance imaging(MRI)for diagnosis,which can lead to MRI failure due to claustrophobia.AIM To explore the val...BACKGROUND Patients with Parkinson’s disease(PD)often experience depression,and some may require magnetic resonance imaging(MRI)for diagnosis,which can lead to MRI failure due to claustrophobia.AIM To explore the value of psychological interventions in successfully completing functional MRI scans of the brain for PD-related depression.METHODS Ninety-six patients with PD were randomly divided into two groups.The control group(47 patients)received general care,and the experimental group(49 patients)received general care combined with psychological care.The Unified Parkinson's Disease Assessment Scale(UPDRS),Hamilton Depression Scale(HAMD),and Geriatric Depression Scale(GDS)-15 scores,heart rate,systolic blood pressure,and MRI-Anxiety Questionnaire(MRI-AQ)scores before and after the scan were recorded.The completion rate of magnetic resonance(MR)scanning,scanning duration,and image quality scores were recorded.RESULTS Before scanning,no statistically significant difference was observed between the two groups in terms of heart rate,systolic blood pressure,and UPDRS,HAMD,GDS-15,and MRI-AQ scores.After scanning,systolic blood pressure,MRI-AQ score,and scan time in the experimental group were significantly lower than those in the control group,whereas the scan completion rate and image quality score were significantly higher than those in the control group.CONCLUSION Psychological nursing interventions are helpful in alleviating PD-related depression and assessing MR depression scores and may be helpful in the successful completion of functional MRI scans of the patient's brain.展开更多
Alzheimer's disease(AD)is a prevalent neurodegenerative disease characterized by cognitive decline in the early stage.Mild cognitive impairment(MCI)is considered as an intermediate stage between normal aging and A...Alzheimer's disease(AD)is a prevalent neurodegenerative disease characterized by cognitive decline in the early stage.Mild cognitive impairment(MCI)is considered as an intermediate stage between normal aging and AD.In recent years,studies related to resting-state functional MRI(rs-fMRI)indicated that the occurrence and development process of MCI and AD might be closely linked to spontaneous brain activity and alterations in functional connectivity among brain regions,and rs-fMRI could provide important reference for specific diagnosis and early treatment of MCI and AD.The research progresses of rs-fMRI for MCI and AD were reviewed in this article.展开更多
Mature osteoclasts degrade bone matrix by exocytosis of active proteases from secretory lysosomes through a ruffled border.However,the molecular mechanisms underlying lysosomal trafficking and secretion in osteoclasts...Mature osteoclasts degrade bone matrix by exocytosis of active proteases from secretory lysosomes through a ruffled border.However,the molecular mechanisms underlying lysosomal trafficking and secretion in osteoclasts remain largely unknown.Here,we show with GeneChip analysis that RUN and FYVE domain-containing protein 4(RUFY4)is strongly upregulated during osteoclastogenesis.Mice lacking Rufy4 exhibited a high trabecular bone mass phenotype with abnormalities in osteoclast function in vivo.Furthermore,deleting Rufy4 did not affect osteoclast differentiation,but inhibited bone-resorbing activity due to disruption in the acidic maturation of secondary lysosomes,their trafficking to the membrane,and their secretion of cathepsin K into the extracellular space.Mechanistically,RUFY4 promotes late endosome-lysosome fusion by acting as an adaptor protein between Rab7 on late endosomes and LAMP2 on primary lysosomes.Consequently,Rufy4-deficient mice were highly protected from lipopolysaccharide-and ovariectomy-induced bone loss.Thus,RUFY4 plays as a new regulator in osteoclast activity by mediating endo-lysosomal trafficking and have a potential to be specific target for therapies against bone-loss diseases such as osteoporosis.展开更多
Objective To explore the value of deep learning(DL)models semi-automatic training system for automatic optimization of clinical image quality control of transthoracic echocardiography(TTE).Methods Totally 1250 TTE vid...Objective To explore the value of deep learning(DL)models semi-automatic training system for automatic optimization of clinical image quality control of transthoracic echocardiography(TTE).Methods Totally 1250 TTE videos from 402 patients were retrospectively collected,including 490 apical four chamber(A4C),310 parasternal long axis view of left ventricle(PLAX)and 450 parasternal short axis view of great vessel(PSAX GV).The videos were divided into development set(245 A4C,155 PLAX,225 PSAX GV),semi-automated training set(98 A4C,62 PLAX,90 PSAX GV)and test set(147 A4C,93 PLAX,135 PSAX GV)at the ratio of 5∶2∶3.Based on development set and semi-automatic training set,DL model of quality control was semi-automatically iteratively optimized,and a semi-automatic training system was constructed,then the efficacy of DL models for recognizing TTE views and assessing imaging quality of TTE were verified in test set.Results After optimization,the overall accuracy,precision,recall,and F1 score of DL models for recognizing TTE views in test set improved from 97.33%,97.26%,97.26%and 97.26%to 99.73%,99.65%,99.77%and 99.71%,respectively,while the overall accuracy for assessing A4C,PLAX and PSAX GV TTE as standard views in test set improved from 89.12%,83.87%and 90.37%to 93.20%,90.32%and 93.33%,respectively.Conclusion The developed DL models semi-automatic training system could improve the efficiency of clinical imaging quality control of TTE and increase iteration speed.展开更多
BACKGROUND Previous research has highlighted correlations between blood cell counts and chronic liver disease.Nonetheless,the causal relationships remain unknown.AIM To evaluate the causal effect of blood cell traits ...BACKGROUND Previous research has highlighted correlations between blood cell counts and chronic liver disease.Nonetheless,the causal relationships remain unknown.AIM To evaluate the causal effect of blood cell traits on liver enzymes and nonalcoholic fatty liver disease(NAFLD)risk.METHODS Independent genetic variants strongly associated with blood cell traits were extracted from a genome-wide association study(GWAS)conducted by the Blood Cell Consortium.Summary-level data for liver enzymes were obtained from the United Kingdom Biobank.NAFLD data were obtained from a GWAS meta-analysis(8434 cases and 770180 controls,discovery dataset)and the Fingen GWAS(2275 cases and 372727 controls,replication dataset).This analysis was conducted using the inverse-variance weighted method,followed by various sensitivity analyses.RESULTS One SD increase in the genetically predicted haemoglobin concentration(HGB)was associated with aβof 0.0078(95%CI:0.0059-0.0096),0.0108(95%CI:0.0080-0.0136),0.0361(95%CI:0.0156-0.0567),and 0.0083(95%CI:00046-0.0121)for alkaline phosphatase(ALP),alanine aminotransferase(ALT),aspartate aminotransferase,and gammaglutamyl transferase,respectively.Genetically predicted haematocrit was associated with ALP(β=0.0078,95%CI:0.0052-0.0104)and ALT(β=0.0057,95%CI:0.0039-0.0075).Genetically determined HGB and the reticulocyte fraction of red blood cells increased the risk of NAFLD[odds ratio(OR)=1.199,95%CI:1.087-1.322]and(OR=1.157,95%CI:1.071-1.250).The results of the sensitivity analyses remained significant.CONCLUSION Novel causal blood cell traits related to liver enzymes and NAFLD development were revealed through Mendelian randomization analysis,which may facilitate the diagnosis and prevention of NAFLD.展开更多
BACKGROUND Fibroadenoma(FA)is the most common tumor found in young women,although it can occur in any age group.Ductal carcinoma in situ(DCIS)that is confined in a FA is rare;it is most frequently reported as an incid...BACKGROUND Fibroadenoma(FA)is the most common tumor found in young women,although it can occur in any age group.Ductal carcinoma in situ(DCIS)that is confined in a FA is rare;it is most frequently reported as an incidental finding.CASE SUMMARY We report a case of DCIS within a FA in a 46-year-old female without cancerrelated personal and family histories.The patient was diagnosed with a breast conglomerate of nodules and was followed for 1 year.In the current control image study,we found suspicious microcalcification,as a new finding,within one of the nodules.Consequently,a core biopsy of the tumor,which appeared hypoechoic,oval,and circumscribed,was performed.The pathological diagnosis was ductal carcinoma in situ within a fibroepithelial lesion.The patient underwent breastconserving surgery and received radiotherapy as well as endocrine therapy(tamoxifen).CONCLUSION We recommend a multidisciplinary approach for adequate treatment and followup.展开更多
Although rare, intraneural hemangiomas should be considered in the differential diagnosis of peripheral nerve lesions. We report on a 59-year-old female patient, who was admitted to the hospital due to the discovery o...Although rare, intraneural hemangiomas should be considered in the differential diagnosis of peripheral nerve lesions. We report on a 59-year-old female patient, who was admitted to the hospital due to the discovery of bilateral breast masses for 3 months, there was no paresthesia or dyskinesia. The patient accidentally found a mass in the right upper mediastinum while completing a plain chest X-ray, initially suspected as a benign neurilemmoma on CT. Surgical resection and pathological analysis confirmed an intraneural hemangioma. Unexpectedly, the patient developed new-onset right upper limb numbness and paresthesia 3 months post-operatively, probably related to surgical nerve injury. This case underscores the importance of maintaining a broad differential for mediastinal masses, and the potential for iatrogenic neurological complications when managing these rare, yet vascular lesions.展开更多
In the Saloum region of central-western Senegal, water needs are essentially met by tapping an underground aquifer associated with the sandy-clay formations of the Continental Terminal, in contact with both the ocean ...In the Saloum region of central-western Senegal, water needs are essentially met by tapping an underground aquifer associated with the sandy-clay formations of the Continental Terminal, in contact with both the ocean to the west and the highly saline waters of the Saloum River to the north. In this estuarine and deltaic zone with its very low relief, the hydraulic loads in the water tables are generally close to zero or even negative, creating a reversal of the natural flow and encouraging saline intrusion into this system, which makes it very vulnerable. This study concerns the implementation of a numerical model of saline intrusion to provide a better understanding of the vulnerability of the water table by analyzing the variability of the freshwater/saltwater interface. The Modflow-2005 code is used to simulate saline intrusion using the SWI2 module, coupled with the GRASS (Geographic Resources Analysis Support System) software under the Linux operating system with the steep interface approach. The probable expansion of the wedge is studied in three scenarios, taking into account its position relative to the bedrock at 1 m, 5 m and 10 m. Simulations carried out under imposed potential and river conditions, based on variations in groundwater reserves using two effective porosity values, 10−1 and 10−2, show that the water table is highly vulnerable in the northwest sector. The probable expansion of the wedge increases as the storage coefficient decreases and is more marked with river conditions in the areas surrounding the Saloum River, reaching 6 km with a probability of 1. The probability of the wedge reaching a certain degree of expansion decreases from 1 to 0.5, and then cancels out as it moves inland. The probable position of the wedge is limited to 500 m or even 1 km depending on the corner around the coast to the southwest and in the southern zone. This modelling, carried out under natural conditions, will be developed further, taking into account climatic parameters and pumping from wells and boreholes.展开更多
Background:The prevalence,age of onset,and symptomatology of traumatic brain injury,stroke,and neurodegenerative diseases(such as Alzheimer’s disease(AD),Parkinson’s disease,amyotrophic lateral sclerosis,and Hunting...Background:The prevalence,age of onset,and symptomatology of traumatic brain injury,stroke,and neurodegenerative diseases(such as Alzheimer’s disease(AD),Parkinson’s disease,amyotrophic lateral sclerosis,and Huntington’s disease)differ substantially between males and females.The higher prevalence of these brain disorders has been attributed to females having a greater longevity compared with males.Since one of the greatest risk factors of acquired brain injury(such as stroke,traumatic brain injury caused by fall)and neurodegenerative disease is age.展开更多
BACKGROUND Changes in alkaline phosphatase(ALP)andγ-glutamyltransferase(GGT)levels in patients with primary liver cancer(PLC)after radiofrequency ablation(RFA).Hepatocellular carcinoma is a malignant tumor with high ...BACKGROUND Changes in alkaline phosphatase(ALP)andγ-glutamyltransferase(GGT)levels in patients with primary liver cancer(PLC)after radiofrequency ablation(RFA).Hepatocellular carcinoma is a malignant tumor with high incidence worldwide.As a common local treatment,RFA has attracted much attention for its efficacy and influence on liver function.AIM To investigate the effect of serum ALP and GGT levels on the prognosis of patients with PLC treated by RFA.METHODS The preoperative clinical data of 165 patients who were pathologically or clinically diagnosed with PLC and who received RFA in our hospital between October 2018 and June 2023 were collected.The chi-square test was used to compare the data between groups.The Kaplan-Meier method and Cox regression were used to analyze the associ-ations between serum ALP and GGT levels and overall survival,progression-free survival(PFS)and clinical characteristics of patients before treatment.RESULTS The 1-year survival rates of patients with normal(≤135 U/L)and abnormal(>135 U/L)serum ALP before treatment were 91%and 79%,respectively;the 2-year survival rates were 90%and 68%,respectively;and the 5-year survival rates were 35%and 18%,respectively.The difference between the two groups was statistically significant(P=0.01).Before treatment,the 1-year survival rates of patients with normal serum GGT levels(≤45 U/L)and abnormal serum GGT levels(>45 U/L)were 95%and 87%,the 2-year survival rates were 85%and 71%,and the 5-year survival rates were 37%and 21%,respectively.The difference between the two groups was statist-ically significant(P<0.001).Serum ALP[hazard ratio(HR)=1.766,95%confidence interval(95%CI):1.068-2.921,P=0.027]and GGT(HR=2.312,95%CI:1.367-3.912,P=0.002)is closely related to the overall survival of PLC patients after RF ablation and is an independent prognostic factor.The 1-year PFS rates were 72%and 50%,the 2-year PFS rates were 52%and 21%,and the 5-year PFS rates were 14%and 3%,respectively.The difference between the two groups was statistically significant(P<0001).The 1-year PFS rates were 81%and 56%in patients with normal and abnormal serum GGT levels before treatment,respectively;the 2-year PFS rates were 62%and 35%,respectively;and the 5-year PFS rates were 18%and 7%,respectively,with statistical significance between the two groups(P<0.001).The serum ALP concentration(HR=1.653,95%CI:1.001-2.729,P=0.049)and GGT(HR=1.949,95%CI:1.296-2.930,P=0.001)was closely associated with PFS after RFA in patients with PLC.The proportion of male patients with abnormal ALP levels is high,the Child-Pugh grade of liver function is poor,and the incidence of ascites is high.Among GGT-abnormal patients,the Child-Pugh grade of liver function was poor,the tumor stage was late,the proportion of patients with tumors≥5 cm was high,and the incidence of hepatic encephalopathy was high.CONCLUSION Serum ALP and GGT levels before treatment can be used to predict the prognosis of patients with PLC after RFA,and they have certain guiding significance for the long-term survival of patients with PLC after radiofrequency therapy.展开更多
Aim: Lead aprons are used to protect against scattered radiation from the patient during interventional procedures and certain special conventional radiological examinations. Given the importance of the role lead apro...Aim: Lead aprons are used to protect against scattered radiation from the patient during interventional procedures and certain special conventional radiological examinations. Given the importance of the role lead aprons are supposed to play in radiation protection, we propose to assess their conformity in medical imaging departments in public and religious hospitals in Togo. Materials and method: A multi-centre survey conducted from 26 November to 06 December 2021 in the radiology departments of public and religious health facilities in Togo. All aprons in use were included. The evaluation criteria were physical (visual), quantitative (radiographic) and qualitative (dosimetric). Results: We had registred 43 aprons among wich 27 (62.79%) leaded aprons were labelled non-compliant and 16 (37.21%) were labelled compliant. Of the aprons judged to be non-compliant, 70.37% were more than 10 years old and 96.30% showed defects on the radiographic images. The most common defects were vampire marks (18.64%), multiple folds (16.96%), cracks (16.96%), multiple cracks (15.25%), tears (8.47%), absence of lead (5.08%), holes (3.39%) and lead corrosion (1.69%). Defective aprons (62.96%) had at least two defects. The defects were of thoraco-abdomino-pelvic (74.07%), thoracic (14.82%) and abdomino-pelvic (11.11%) topography. For indirect exposure at 50 and 70 kilovolts, all the aprons had an attenuation factor greater than 90%. After dosimetric measurement, 13.95% of aprons had attenuation factors below 90% for indirect exposure at 100 kilovolts. Conclusion: The compliance of the leaded decks is trifactorial (physical, radiographic and dosimetric). However, there is no significant difference in X-ray attenuation capacity between defective and normal decks.展开更多
Objective: To explore the role of the texture features of images in the diagnosis of solitary pulmonary nodules (SPNs) in different sizes. Materials and methods: A total of 379 patients with pathologically confirm...Objective: To explore the role of the texture features of images in the diagnosis of solitary pulmonary nodules (SPNs) in different sizes. Materials and methods: A total of 379 patients with pathologically confirmed SPNs were enrolled in this study. They were divided into three groups based on the SPN sizes: ≤10, 11-20, and 〉20 mm. Their texture features were segmented and extracted. The differences in the image features between benign and malignant SPNs were compared. The SPNs in these three groups were determined and analyzed with the texture features of images. Results: These 379 SPNs were successfully segmented using the 2D Otsu threshold method and the self-adaptive threshold segmentation method. The texture features of these SPNs were obtained using the method of grey level co-occurrence matrix (GLCM). Of these 379 patients, 120 had benign SPNs and 259 had malignant SPNs. The entropy, contrast, energy, homogeneity, and correlation were 3.5597±0.6470, 0.5384±0.2561, 0.1921±0.1256, 0.8281±0.0604, and 0.8748±0.0740 in the benign SPNs and 3.8007±0.6235, 0.6088±0.2961, 0.1673±0.1070, 0.7980±0.0555, and 0.8550±0.0869 in the malignant SPNs (all P〈0.05). The sensitivity, specificity, and accuracy of the texture features of images were 83.3%, 90.0%, and 86.8%, respectively, for SPNs sized 〈10 mm, and were 86.6%, 88.2%, and 87.1%, respectively, for SPNs sized 11-20 mm and 94.7%, 91.8%, and 93.9%, respectively, for SPNs sized 〉20 mm. Conclusions: The entropy and contrast of malignant pulmonary nodules have been demonstrated to be higher in comparison to those of benign pulmonary nodules, while the energy, homogeneity correlation of malignant pulmonary nodules are lower than those of benign pulmonary nodules. The texture features of images can reflect the tissue features and have high sensitivity, specificity, and accuracy in differentiating SPNs. The sensitivity and accuracy increase for larger SPNs.展开更多
In image-guided radiation therapy, extracting features from medical point cloud is the key technique for multimodality registration. This novel framework, denoted Control Point Net (CPN), provides an alternative to th...In image-guided radiation therapy, extracting features from medical point cloud is the key technique for multimodality registration. This novel framework, denoted Control Point Net (CPN), provides an alternative to the common applications of manually designed keypoint descriptors for coarse point cloud registration. The CPN directly consumes a point cloud, divides it into equally spaced 3D voxels and transforms the points within each voxel into a unified feature representation through voxel feature encoding (VFE) layer. Then all volumetric representations are aggregated by Weighted Extraction Layer which selectively extracts features and synthesize into global descriptors and coordinates of control points. Utilizing global descriptors instead of local features allows the available geometrical data to be better exploited to improve the robustness and precision. Specifically, CPN unifies feature extraction and clustering into a single network, omitting time-consuming feature matching procedure. The algorithm is tested on point cloud datasets generated from CT images. Experiments and comparisons with the state-of-the-art descriptors demonstrate that CPN is highly discriminative, efficient, and robust to noise and density changes.展开更多
Objective: To establish a rodent model of VX2 tumor of the spleen, to analyze relationship between the change of the signal intensity on superparamagnetic iron oxide enhanced magnetic resonance image (MRI) and path...Objective: To establish a rodent model of VX2 tumor of the spleen, to analyze relationship between the change of the signal intensity on superparamagnetic iron oxide enhanced magnetic resonance image (MRI) and pathologic change to evaluate the ability of superparamagnetic iron oxide enhanced MRI for detection of splenic metastases. Methods: 8 rodent models of VX2 tumor of spleen were established successfully. The images were obtained before and after administration of superparamagnetic iron oxide. T1-weighted spin-echo (SE) pulse sequence with a repetition time (TR) of 450 msec, and echo time (TE) of 12 msec (TR/TE=450/12) was used. The imaging parameters of T2-weighted SE pulse sequence were as follows: TR/TE=4000/128. Results: On plain MR scanning T1-weighted splenic VX2 tumor showed hypointensity or isointensity which approximated to the SI of splenic parenchyma. Therefore all lesions were not displayed clearly. On superparamagnetic iron oxide enhancement T2WI sequence the SI of splenic parenchyma decreased obviously with percentage of signal intensity loss (PSIL) of 55.04%, But the SI of tumor was not evidently changed with PSIL of 0.87%. Nevertheless the SNR of normal splenic parenchyma around the lesions had obvious difference (P〈0.001) comparatively. Therefore the contrast between tumor and spleen increased, and tumor displayed more clearly. Moreover the contrast-to-noise (CNR) between VX2 tumor and splenic parenchyma had an evident difference before and after admininstration of superparamagnetic iron oxide (P〈0.001). Conclusion: On superparamagnetic iron oxide enhancement T1WI sequence the contrast of tumor-to-spleen is poor. Therefore it is not sensitive to characterize the lesions in spleen. On superparamagnetic iron oxide enhanced T2WI the contrast degree of lesions increases obviously. Consequently, superparamagnetic iron oxide -enhanced T2WI MRI scanning can improve the rate of detection and characterization for lesions of spleen.展开更多
This paper discusses a pattern design system in textile industry,the establishment of an imagedatabase which is used to store various kinds of source materials for designers’ reference in order tospeed up design proc...This paper discusses a pattern design system in textile industry,the establishment of an imagedatabase which is used to store various kinds of source materials for designers’ reference in order tospeed up design process.Pattern design image database (PDIDB) runs on the double-machine hardware system com-posed of ALTOS-986 and IBM PC/XT microcomputer.The former (host) manages imagedatabase,and the latter works both as a terminal to operate PDIDB and as an image processingstation to input,output,edit and display image data.PDIDB has two mainparts,the image storage management system and the image attributemanagement system and provides some functions,such as retrieval,deleting and updating.展开更多
文摘Introduction: MRI is a rapidly growing technique with more and more indica-tions and requests in the Republic of Guinea. Its correct prescription is a guar-antee for the satisfaction of the actors, both prescribers, radiologists and pa-tients. The main objective of this study was to evaluate the compliance of MRI examination requests at the Diagnostic Center of the National Social Se-curity Fund (CNSS) in Conakry. Material and Methods: This was a descriptive cross-sectional study of MRI prescription forms sent to the MRI unit of the CNSS Diagnostic Center from February 1 to May 1, 2021. The 8 compliance criteria established by the French High Authority for Health were used to evaluate the compliance of the examination requests. Results: A total of 7003 examination forms were sent to the facility, including 7% (n = 468) of MRIs. 56.2% of MRI requests were performed by specialists. We observed an overall compliance of 10%. Administrative and clinical compliance were missing in 24% and 38%, respectively. More specifically, the purpose of the examination was not mentioned in 60%, followed by the requesting department in 48.1% and the patient’s age in 35.1%. Conclusion: This study allowed us to highlight the gaps in establishing MRI requests. It would be important to organize an awareness campaign for prescribers on the usefulness of correctly filling an MRI request and to design templates to be filled out by prescribers.
文摘Breast pathology is varied, bringing together tumor and non-tumor lesions. Objective: To study the contribution of the ultrasound-mammography pair in the diagnosis of breast pathologies. Materials and Method: This was a retrospective descriptive study, carried out over a period of 3 years (from January 2018 to December 2020) at the Diagnostic Imaging Center (C.I.D) “TERIYA” in BAMAKO. It concerned all patients who came for a mammogram/ultrasound examination of the breast. All women admitted for mammogram or breast ultrasound who were diagnosed with a breast injury during the study period were included. Incomplete records and radiological checks were not included. The variables analyzed were age, sex, clinical data, and ultrasound and mammography aspects. The devices used are: a Voluson 730 PRO ultrasound machine and a G 600T type mammography machine. Results: At the end of our study, we collected 254 breast pathologies on a number of 382 women, i.e. a frequency of 66.49%. The average age of our patients was 41 years old. The dominant clinical data were mastodynia (41.88%) and mammary nodule (21.70%). On imaging (mammo-ultrasound) the lesions predominated on the left in 36% of cases, bilateral in 28% of cases and in the upper-outer quadrants in 31.5% of cases. Tumor pathologies represented 66.54% of which 45.27% were benign mainly composed of fibro-adenoma (20.88%) and cyst (18.50%), 11.8% of suspected cases and 9.45% of cancers. Non-tumor pathologies represented 33.46%, mainly mastitis (16.14%), galactophoric dilations (11.02%) and abscesses (5.51%). These pathologies were classified in 50.3% in ACR2, 17.75% in ACR3 and 4, and in 14.20% in ACR5. Lymphadenopathy was present in 73.21% of cases.
基金supported by China Scholarship Council(202208210093,to RJ)。
文摘Cerebral small vessel disease is a neurological disease that affects the brain microvasculature and which is commonly observed among the elderly.Although at first it was considered innocuous,small vessel disease is nowadays regarded as one of the major vascular causes of dementia.Radiological signs of small vessel disease include small subcortical infarcts,white matter magnetic resonance imaging hyperintensities,lacunes,enlarged perivascular spaces,cerebral microbleeds,and brain atrophy;however,great heterogeneity in clinical symptoms is observed in small vessel disease patients.The pathophysiology of these lesions has been linked to multiple processes,such as hypoperfusion,defective cerebrovascular reactivity,and blood-brain barrier dysfunction.Notably,studies on small vessel disease suggest that blood-brain barrier dysfunction is among the earliest mechanisms in small vessel disease and might contribute to the development of the hallmarks of small vessel disease.Therefore,the purpose of this review is to provide a new foundation in the study of small vessel disease pathology.First,we discuss the main structural domains and functions of the blood-brain barrier.Secondly,we review the most recent evidence on blood-brain barrier dysfunction linked to small vessel disease.Finally,we conclude with a discussion on future perspectives and propose potential treatment targets and interventions.
基金partly funded by the Clinician-Scientist grant(No.472-0-0)by the medical faculty of the University of Tübingen(to SCV).
文摘Ambroxol hydrochloride(2-amino-3,5-dibromo-N-methylbenzylamine hydrochloride)has been used as a mucolytic agent in the treatment of respiratory diseases since the late 1970s.Its effects on mucus membranes such as mucus disruption,increased mucus production,and low toxicity profile were addressed in its original German patent in 1966.These first described properties have kept Ambroxol available worldwide and over the counter in the pharmaceutical market to this day.
基金Supported by Qinhuangdao Science-Technology Support Projects of China,No.202101A141.
文摘BACKGROUND Patients with Parkinson’s disease(PD)often experience depression,and some may require magnetic resonance imaging(MRI)for diagnosis,which can lead to MRI failure due to claustrophobia.AIM To explore the value of psychological interventions in successfully completing functional MRI scans of the brain for PD-related depression.METHODS Ninety-six patients with PD were randomly divided into two groups.The control group(47 patients)received general care,and the experimental group(49 patients)received general care combined with psychological care.The Unified Parkinson's Disease Assessment Scale(UPDRS),Hamilton Depression Scale(HAMD),and Geriatric Depression Scale(GDS)-15 scores,heart rate,systolic blood pressure,and MRI-Anxiety Questionnaire(MRI-AQ)scores before and after the scan were recorded.The completion rate of magnetic resonance(MR)scanning,scanning duration,and image quality scores were recorded.RESULTS Before scanning,no statistically significant difference was observed between the two groups in terms of heart rate,systolic blood pressure,and UPDRS,HAMD,GDS-15,and MRI-AQ scores.After scanning,systolic blood pressure,MRI-AQ score,and scan time in the experimental group were significantly lower than those in the control group,whereas the scan completion rate and image quality score were significantly higher than those in the control group.CONCLUSION Psychological nursing interventions are helpful in alleviating PD-related depression and assessing MR depression scores and may be helpful in the successful completion of functional MRI scans of the patient's brain.
文摘Alzheimer's disease(AD)is a prevalent neurodegenerative disease characterized by cognitive decline in the early stage.Mild cognitive impairment(MCI)is considered as an intermediate stage between normal aging and AD.In recent years,studies related to resting-state functional MRI(rs-fMRI)indicated that the occurrence and development process of MCI and AD might be closely linked to spontaneous brain activity and alterations in functional connectivity among brain regions,and rs-fMRI could provide important reference for specific diagnosis and early treatment of MCI and AD.The research progresses of rs-fMRI for MCI and AD were reviewed in this article.
基金supported by grants from the National Research Foundation of Korea(RS-2023-00217798 and 2021R1A2C3003675 to S.Y.L.)by the Korea Basic Science Institute National Research Facilities&Equipment Center grant(2019R1A6C1010020).M.K.was supported in part by scholarship from Ewha Womans University.
文摘Mature osteoclasts degrade bone matrix by exocytosis of active proteases from secretory lysosomes through a ruffled border.However,the molecular mechanisms underlying lysosomal trafficking and secretion in osteoclasts remain largely unknown.Here,we show with GeneChip analysis that RUN and FYVE domain-containing protein 4(RUFY4)is strongly upregulated during osteoclastogenesis.Mice lacking Rufy4 exhibited a high trabecular bone mass phenotype with abnormalities in osteoclast function in vivo.Furthermore,deleting Rufy4 did not affect osteoclast differentiation,but inhibited bone-resorbing activity due to disruption in the acidic maturation of secondary lysosomes,their trafficking to the membrane,and their secretion of cathepsin K into the extracellular space.Mechanistically,RUFY4 promotes late endosome-lysosome fusion by acting as an adaptor protein between Rab7 on late endosomes and LAMP2 on primary lysosomes.Consequently,Rufy4-deficient mice were highly protected from lipopolysaccharide-and ovariectomy-induced bone loss.Thus,RUFY4 plays as a new regulator in osteoclast activity by mediating endo-lysosomal trafficking and have a potential to be specific target for therapies against bone-loss diseases such as osteoporosis.
文摘Objective To explore the value of deep learning(DL)models semi-automatic training system for automatic optimization of clinical image quality control of transthoracic echocardiography(TTE).Methods Totally 1250 TTE videos from 402 patients were retrospectively collected,including 490 apical four chamber(A4C),310 parasternal long axis view of left ventricle(PLAX)and 450 parasternal short axis view of great vessel(PSAX GV).The videos were divided into development set(245 A4C,155 PLAX,225 PSAX GV),semi-automated training set(98 A4C,62 PLAX,90 PSAX GV)and test set(147 A4C,93 PLAX,135 PSAX GV)at the ratio of 5∶2∶3.Based on development set and semi-automatic training set,DL model of quality control was semi-automatically iteratively optimized,and a semi-automatic training system was constructed,then the efficacy of DL models for recognizing TTE views and assessing imaging quality of TTE were verified in test set.Results After optimization,the overall accuracy,precision,recall,and F1 score of DL models for recognizing TTE views in test set improved from 97.33%,97.26%,97.26%and 97.26%to 99.73%,99.65%,99.77%and 99.71%,respectively,while the overall accuracy for assessing A4C,PLAX and PSAX GV TTE as standard views in test set improved from 89.12%,83.87%and 90.37%to 93.20%,90.32%and 93.33%,respectively.Conclusion The developed DL models semi-automatic training system could improve the efficiency of clinical imaging quality control of TTE and increase iteration speed.
基金the Shanghai Natural Science Foundation of China,No.23ZR1447800and the Fengxian District Science and Technology Commission Project,China,No.20211838.
文摘BACKGROUND Previous research has highlighted correlations between blood cell counts and chronic liver disease.Nonetheless,the causal relationships remain unknown.AIM To evaluate the causal effect of blood cell traits on liver enzymes and nonalcoholic fatty liver disease(NAFLD)risk.METHODS Independent genetic variants strongly associated with blood cell traits were extracted from a genome-wide association study(GWAS)conducted by the Blood Cell Consortium.Summary-level data for liver enzymes were obtained from the United Kingdom Biobank.NAFLD data were obtained from a GWAS meta-analysis(8434 cases and 770180 controls,discovery dataset)and the Fingen GWAS(2275 cases and 372727 controls,replication dataset).This analysis was conducted using the inverse-variance weighted method,followed by various sensitivity analyses.RESULTS One SD increase in the genetically predicted haemoglobin concentration(HGB)was associated with aβof 0.0078(95%CI:0.0059-0.0096),0.0108(95%CI:0.0080-0.0136),0.0361(95%CI:0.0156-0.0567),and 0.0083(95%CI:00046-0.0121)for alkaline phosphatase(ALP),alanine aminotransferase(ALT),aspartate aminotransferase,and gammaglutamyl transferase,respectively.Genetically predicted haematocrit was associated with ALP(β=0.0078,95%CI:0.0052-0.0104)and ALT(β=0.0057,95%CI:0.0039-0.0075).Genetically determined HGB and the reticulocyte fraction of red blood cells increased the risk of NAFLD[odds ratio(OR)=1.199,95%CI:1.087-1.322]and(OR=1.157,95%CI:1.071-1.250).The results of the sensitivity analyses remained significant.CONCLUSION Novel causal blood cell traits related to liver enzymes and NAFLD development were revealed through Mendelian randomization analysis,which may facilitate the diagnosis and prevention of NAFLD.
文摘BACKGROUND Fibroadenoma(FA)is the most common tumor found in young women,although it can occur in any age group.Ductal carcinoma in situ(DCIS)that is confined in a FA is rare;it is most frequently reported as an incidental finding.CASE SUMMARY We report a case of DCIS within a FA in a 46-year-old female without cancerrelated personal and family histories.The patient was diagnosed with a breast conglomerate of nodules and was followed for 1 year.In the current control image study,we found suspicious microcalcification,as a new finding,within one of the nodules.Consequently,a core biopsy of the tumor,which appeared hypoechoic,oval,and circumscribed,was performed.The pathological diagnosis was ductal carcinoma in situ within a fibroepithelial lesion.The patient underwent breastconserving surgery and received radiotherapy as well as endocrine therapy(tamoxifen).CONCLUSION We recommend a multidisciplinary approach for adequate treatment and followup.
文摘Although rare, intraneural hemangiomas should be considered in the differential diagnosis of peripheral nerve lesions. We report on a 59-year-old female patient, who was admitted to the hospital due to the discovery of bilateral breast masses for 3 months, there was no paresthesia or dyskinesia. The patient accidentally found a mass in the right upper mediastinum while completing a plain chest X-ray, initially suspected as a benign neurilemmoma on CT. Surgical resection and pathological analysis confirmed an intraneural hemangioma. Unexpectedly, the patient developed new-onset right upper limb numbness and paresthesia 3 months post-operatively, probably related to surgical nerve injury. This case underscores the importance of maintaining a broad differential for mediastinal masses, and the potential for iatrogenic neurological complications when managing these rare, yet vascular lesions.
文摘In the Saloum region of central-western Senegal, water needs are essentially met by tapping an underground aquifer associated with the sandy-clay formations of the Continental Terminal, in contact with both the ocean to the west and the highly saline waters of the Saloum River to the north. In this estuarine and deltaic zone with its very low relief, the hydraulic loads in the water tables are generally close to zero or even negative, creating a reversal of the natural flow and encouraging saline intrusion into this system, which makes it very vulnerable. This study concerns the implementation of a numerical model of saline intrusion to provide a better understanding of the vulnerability of the water table by analyzing the variability of the freshwater/saltwater interface. The Modflow-2005 code is used to simulate saline intrusion using the SWI2 module, coupled with the GRASS (Geographic Resources Analysis Support System) software under the Linux operating system with the steep interface approach. The probable expansion of the wedge is studied in three scenarios, taking into account its position relative to the bedrock at 1 m, 5 m and 10 m. Simulations carried out under imposed potential and river conditions, based on variations in groundwater reserves using two effective porosity values, 10−1 and 10−2, show that the water table is highly vulnerable in the northwest sector. The probable expansion of the wedge increases as the storage coefficient decreases and is more marked with river conditions in the areas surrounding the Saloum River, reaching 6 km with a probability of 1. The probability of the wedge reaching a certain degree of expansion decreases from 1 to 0.5, and then cancels out as it moves inland. The probable position of the wedge is limited to 500 m or even 1 km depending on the corner around the coast to the southwest and in the southern zone. This modelling, carried out under natural conditions, will be developed further, taking into account climatic parameters and pumping from wells and boreholes.
基金supported by NIH/NICHD R01 HD109157.Dr.Yang’s time on this work was also supported by his American Heart Association Award Career Development Award(932980)National Science Foundation CAREER award(NSF 2401215).
文摘Background:The prevalence,age of onset,and symptomatology of traumatic brain injury,stroke,and neurodegenerative diseases(such as Alzheimer’s disease(AD),Parkinson’s disease,amyotrophic lateral sclerosis,and Huntington’s disease)differ substantially between males and females.The higher prevalence of these brain disorders has been attributed to females having a greater longevity compared with males.Since one of the greatest risk factors of acquired brain injury(such as stroke,traumatic brain injury caused by fall)and neurodegenerative disease is age.
基金Yunnan Province High-level Scientific and Technological Talents and Innovation Team Selection Special,No.202405AC350067Basic Research Joint Special General Project of Yunnan Provincial Local Universities(Part),No.202301BA070001-029 and No.202301BA070001-044+1 种基金Scientific Research Fund Project of Education Department of Yunnan Province,No.2023J0926The 8th Research Project of Education and Teaching Reform of Dali University(Special Medical Education Reform Project),No.2022JGYX08-01 and No.2022JGYX08-02.
文摘BACKGROUND Changes in alkaline phosphatase(ALP)andγ-glutamyltransferase(GGT)levels in patients with primary liver cancer(PLC)after radiofrequency ablation(RFA).Hepatocellular carcinoma is a malignant tumor with high incidence worldwide.As a common local treatment,RFA has attracted much attention for its efficacy and influence on liver function.AIM To investigate the effect of serum ALP and GGT levels on the prognosis of patients with PLC treated by RFA.METHODS The preoperative clinical data of 165 patients who were pathologically or clinically diagnosed with PLC and who received RFA in our hospital between October 2018 and June 2023 were collected.The chi-square test was used to compare the data between groups.The Kaplan-Meier method and Cox regression were used to analyze the associ-ations between serum ALP and GGT levels and overall survival,progression-free survival(PFS)and clinical characteristics of patients before treatment.RESULTS The 1-year survival rates of patients with normal(≤135 U/L)and abnormal(>135 U/L)serum ALP before treatment were 91%and 79%,respectively;the 2-year survival rates were 90%and 68%,respectively;and the 5-year survival rates were 35%and 18%,respectively.The difference between the two groups was statistically significant(P=0.01).Before treatment,the 1-year survival rates of patients with normal serum GGT levels(≤45 U/L)and abnormal serum GGT levels(>45 U/L)were 95%and 87%,the 2-year survival rates were 85%and 71%,and the 5-year survival rates were 37%and 21%,respectively.The difference between the two groups was statist-ically significant(P<0.001).Serum ALP[hazard ratio(HR)=1.766,95%confidence interval(95%CI):1.068-2.921,P=0.027]and GGT(HR=2.312,95%CI:1.367-3.912,P=0.002)is closely related to the overall survival of PLC patients after RF ablation and is an independent prognostic factor.The 1-year PFS rates were 72%and 50%,the 2-year PFS rates were 52%and 21%,and the 5-year PFS rates were 14%and 3%,respectively.The difference between the two groups was statistically significant(P<0001).The 1-year PFS rates were 81%and 56%in patients with normal and abnormal serum GGT levels before treatment,respectively;the 2-year PFS rates were 62%and 35%,respectively;and the 5-year PFS rates were 18%and 7%,respectively,with statistical significance between the two groups(P<0.001).The serum ALP concentration(HR=1.653,95%CI:1.001-2.729,P=0.049)and GGT(HR=1.949,95%CI:1.296-2.930,P=0.001)was closely associated with PFS after RFA in patients with PLC.The proportion of male patients with abnormal ALP levels is high,the Child-Pugh grade of liver function is poor,and the incidence of ascites is high.Among GGT-abnormal patients,the Child-Pugh grade of liver function was poor,the tumor stage was late,the proportion of patients with tumors≥5 cm was high,and the incidence of hepatic encephalopathy was high.CONCLUSION Serum ALP and GGT levels before treatment can be used to predict the prognosis of patients with PLC after RFA,and they have certain guiding significance for the long-term survival of patients with PLC after radiofrequency therapy.
文摘Aim: Lead aprons are used to protect against scattered radiation from the patient during interventional procedures and certain special conventional radiological examinations. Given the importance of the role lead aprons are supposed to play in radiation protection, we propose to assess their conformity in medical imaging departments in public and religious hospitals in Togo. Materials and method: A multi-centre survey conducted from 26 November to 06 December 2021 in the radiology departments of public and religious health facilities in Togo. All aprons in use were included. The evaluation criteria were physical (visual), quantitative (radiographic) and qualitative (dosimetric). Results: We had registred 43 aprons among wich 27 (62.79%) leaded aprons were labelled non-compliant and 16 (37.21%) were labelled compliant. Of the aprons judged to be non-compliant, 70.37% were more than 10 years old and 96.30% showed defects on the radiographic images. The most common defects were vampire marks (18.64%), multiple folds (16.96%), cracks (16.96%), multiple cracks (15.25%), tears (8.47%), absence of lead (5.08%), holes (3.39%) and lead corrosion (1.69%). Defective aprons (62.96%) had at least two defects. The defects were of thoraco-abdomino-pelvic (74.07%), thoracic (14.82%) and abdomino-pelvic (11.11%) topography. For indirect exposure at 50 and 70 kilovolts, all the aprons had an attenuation factor greater than 90%. After dosimetric measurement, 13.95% of aprons had attenuation factors below 90% for indirect exposure at 100 kilovolts. Conclusion: The compliance of the leaded decks is trifactorial (physical, radiographic and dosimetric). However, there is no significant difference in X-ray attenuation capacity between defective and normal decks.
基金supported by National Natural Science Fund project [81202284]Guangdong Provincial Natural Science Fund project [S2011040004735]+2 种基金Project for Outstanding Young Innovative Talents in Colleges and Universities of Guangdong Province [LYM11106]Special Research Fund for Basic Scientific Research Projects in Central Universities [21612305, 21612101]Guangzhou Municipal Science and Technology Fund project [2014J4100119]
文摘Objective: To explore the role of the texture features of images in the diagnosis of solitary pulmonary nodules (SPNs) in different sizes. Materials and methods: A total of 379 patients with pathologically confirmed SPNs were enrolled in this study. They were divided into three groups based on the SPN sizes: ≤10, 11-20, and 〉20 mm. Their texture features were segmented and extracted. The differences in the image features between benign and malignant SPNs were compared. The SPNs in these three groups were determined and analyzed with the texture features of images. Results: These 379 SPNs were successfully segmented using the 2D Otsu threshold method and the self-adaptive threshold segmentation method. The texture features of these SPNs were obtained using the method of grey level co-occurrence matrix (GLCM). Of these 379 patients, 120 had benign SPNs and 259 had malignant SPNs. The entropy, contrast, energy, homogeneity, and correlation were 3.5597±0.6470, 0.5384±0.2561, 0.1921±0.1256, 0.8281±0.0604, and 0.8748±0.0740 in the benign SPNs and 3.8007±0.6235, 0.6088±0.2961, 0.1673±0.1070, 0.7980±0.0555, and 0.8550±0.0869 in the malignant SPNs (all P〈0.05). The sensitivity, specificity, and accuracy of the texture features of images were 83.3%, 90.0%, and 86.8%, respectively, for SPNs sized 〈10 mm, and were 86.6%, 88.2%, and 87.1%, respectively, for SPNs sized 11-20 mm and 94.7%, 91.8%, and 93.9%, respectively, for SPNs sized 〉20 mm. Conclusions: The entropy and contrast of malignant pulmonary nodules have been demonstrated to be higher in comparison to those of benign pulmonary nodules, while the energy, homogeneity correlation of malignant pulmonary nodules are lower than those of benign pulmonary nodules. The texture features of images can reflect the tissue features and have high sensitivity, specificity, and accuracy in differentiating SPNs. The sensitivity and accuracy increase for larger SPNs.
文摘In image-guided radiation therapy, extracting features from medical point cloud is the key technique for multimodality registration. This novel framework, denoted Control Point Net (CPN), provides an alternative to the common applications of manually designed keypoint descriptors for coarse point cloud registration. The CPN directly consumes a point cloud, divides it into equally spaced 3D voxels and transforms the points within each voxel into a unified feature representation through voxel feature encoding (VFE) layer. Then all volumetric representations are aggregated by Weighted Extraction Layer which selectively extracts features and synthesize into global descriptors and coordinates of control points. Utilizing global descriptors instead of local features allows the available geometrical data to be better exploited to improve the robustness and precision. Specifically, CPN unifies feature extraction and clustering into a single network, omitting time-consuming feature matching procedure. The algorithm is tested on point cloud datasets generated from CT images. Experiments and comparisons with the state-of-the-art descriptors demonstrate that CPN is highly discriminative, efficient, and robust to noise and density changes.
文摘Objective: To establish a rodent model of VX2 tumor of the spleen, to analyze relationship between the change of the signal intensity on superparamagnetic iron oxide enhanced magnetic resonance image (MRI) and pathologic change to evaluate the ability of superparamagnetic iron oxide enhanced MRI for detection of splenic metastases. Methods: 8 rodent models of VX2 tumor of spleen were established successfully. The images were obtained before and after administration of superparamagnetic iron oxide. T1-weighted spin-echo (SE) pulse sequence with a repetition time (TR) of 450 msec, and echo time (TE) of 12 msec (TR/TE=450/12) was used. The imaging parameters of T2-weighted SE pulse sequence were as follows: TR/TE=4000/128. Results: On plain MR scanning T1-weighted splenic VX2 tumor showed hypointensity or isointensity which approximated to the SI of splenic parenchyma. Therefore all lesions were not displayed clearly. On superparamagnetic iron oxide enhancement T2WI sequence the SI of splenic parenchyma decreased obviously with percentage of signal intensity loss (PSIL) of 55.04%, But the SI of tumor was not evidently changed with PSIL of 0.87%. Nevertheless the SNR of normal splenic parenchyma around the lesions had obvious difference (P〈0.001) comparatively. Therefore the contrast between tumor and spleen increased, and tumor displayed more clearly. Moreover the contrast-to-noise (CNR) between VX2 tumor and splenic parenchyma had an evident difference before and after admininstration of superparamagnetic iron oxide (P〈0.001). Conclusion: On superparamagnetic iron oxide enhancement T1WI sequence the contrast of tumor-to-spleen is poor. Therefore it is not sensitive to characterize the lesions in spleen. On superparamagnetic iron oxide enhanced T2WI the contrast degree of lesions increases obviously. Consequently, superparamagnetic iron oxide -enhanced T2WI MRI scanning can improve the rate of detection and characterization for lesions of spleen.
文摘This paper discusses a pattern design system in textile industry,the establishment of an imagedatabase which is used to store various kinds of source materials for designers’ reference in order tospeed up design process.Pattern design image database (PDIDB) runs on the double-machine hardware system com-posed of ALTOS-986 and IBM PC/XT microcomputer.The former (host) manages imagedatabase,and the latter works both as a terminal to operate PDIDB and as an image processingstation to input,output,edit and display image data.PDIDB has two mainparts,the image storage management system and the image attributemanagement system and provides some functions,such as retrieval,deleting and updating.