共查询到20条相似文献,搜索用时 31 毫秒
1.
Walid M. Hussein Ahmed Tohamy Ahmed Magdy M. El-Nesr Talal A. Amer Mohammad R. Habba 《The Egyptian Journal of Radiology and Nuclear Medicine》2017,48(2):393-401
Purpose
To identify predictive factors for platelets normalization and major complications associated with partial splenic embolization (PSE) in patients with chronic liver disease and hypersplenism.Methods and materials
A prospective study included 30 patients were subjected to pre-embolization abdominal US and laboratory testing (WBC, Hemoglobin, Platelet Count, T. Bilirubin, AST, ALT, S. Albumin). PSE were done by super-selective catheterization of splenic artery and embolization by Polyvinyl alcohol with targeted therapeutic splenic infarction rate (>30% to <70–80%). CECT was performed before and 2 weeks after to assess complications (post embolization syndrome, ascites, peritonitis,pleural effusion, and splenic abscess) and infarction size. CBC, liver function tests was done after 2 weeks, 6 months. Platelet count done on the next day after the embolization.Results
Multiple logistic regression analysis showed that the infarction rate could be used as a predictor for platelets normalization (p value = 0.005, OR = 1.493). ROC curve showed that infarction rate above 76% had 100% specificity for platelets normalization after 6 months; infarction rate above 67% had 92.3% specificity. S. Albumin (2.7–3.2 mg/L), Child Score >8 remained significant predictors for major complication (p = 0.035).Conclusion
Platelet count normalization could be achieved by increasing infraction rate to 67–76%. Child Score and serum albumin are the predictive factor for complications. 相似文献2.
Nesreen Mohey Tamir A. Hassan 《The Egyptian Journal of Radiology and Nuclear Medicine》2017,48(1):1-6
Perianal fistula is a common disorder with high tendency to recur in spite of satisfactory surgery. Pelvic MRI is the preferable imaging modality for recognition and assessment of perianal fistulas.
Aim of the work
To evaluate the effectiveness of MRI in grading of primary perianal fistula and verification of its associated findings in correlation with surgical outcome.Subjects and methods
This prospective study included 30 patients with age range 14–44 years. Preoperative MR grading was correlated with surgical outcome.Results
The sensitivity, specificity, PPV, NPV and weighted Kappa of MR grading in correlation with surgery was 95.8%, 83.3%, 95.8%, 83.3% and 0.79 respectively with P value = 0.000Conclusion
MRI is a valuable modality for grading of primary perianal fistula and its complications. Accurate pre-operative grading may reduce the surgical complications and possibility of recurrence. 相似文献3.
Mohamed Aboul-Fotouh Mourad Elsayed M. Mousa 《The Egyptian Journal of Radiology and Nuclear Medicine》2017,48(1):323-327
Objectives
To evaluate accuracy of combined T2 and diffusion weighted images (DWI) in comparison to combined T2WI and dynamic contrast enhanced-magnetic resonance imaging (DCE-MRI) for assessment of the depth of myometrial invasion.Methods
Sixty-two patients diagnosed pathologically as endometrial carcinoma underwent MRI pelvis examination. Technique of examination for each patient includes T1 (axial), T2 (axial, sagittal and oblique sagittal) weighted images. Diffusion weighted images were done with b values of 0 and 1000 s/mm2. Dynamic contrast enhanced-magnetic resonance imaging done after administration of 0.1 mmol/kg gadolinium at 2 ml/s. The pathological diagnosis used as a gold standard for comparison with imaging.Results
Diagnostic accuracy, sensitivity, specificity of combined T2/diffusion weighted images (DWI) were 92%, 90% and 95.6% while for combined T2/dynamic contrast enhancement (DCE) were 79%, 77% and 82.6% for myometrial invasion <50%. The diagnostic accuracy, sensitivity, specificity of combined T2/diffusion weighted images (DWI) were 92%, 95.6% and 90% while for the combined T2/dynamic contrast enhancement (DCE) were 79%, 82.6% and 77% for myometrial invasion >50%.Conclusion
Combined T2WI-DWI has superior diagnostic accuracy compared to combined T2WI-DCE-MRI in assessment of depth of myometrial invasion in endometrial cancer. T2WI-DWI can eliminate contrast material injection especially for patients who cannot tolerate contrast administration. 相似文献4.
Haisam Atta Gehan S. Seifeldein Momen AlMamoun Hisham Imam 《The Egyptian Journal of Radiology and Nuclear Medicine》2017,48(1):107-113
Purpose
To evaluate the role of non-contrast multidetector CT (MDCT) reliability in localizing CSF leaks and skull base defects in correlation to operative findings.Materials and methods
Twenty patients clinically diagnosed to have CSF rhinorrhea; 8 spontaneous and 12 post-traumatic patients were evaluated using 64-rows MDCT with slice section 0.6 mm. CT is considered accurate if correctly determine the site and size of bony defect as matched with operative findings.Results
MDCT accurately detected the site of presumed CSF leak in 19 out of 20 cases with sensitivity 95%. Cribriform plate defect is the most common site of defect in 40% of cases with 75% of cases categorized as Keros type II. The consensus image with fair agreement (K = 0.38) shows that coronal reformat has the highest diagnostic performance in 75% of cases while the least diagnostic value is encountered with the axial plane in 15% of cases (p = 0.095). There is almost a perfect agreement (K = 0.810) between the MDCT measurements and operative size of bony defect with minimal difference in 10% of patients (P < 0.001).Conclusion
Non-contrast MDCT is an accurate reliable non-invasive imaging modality for preoperative evaluation of CSF rhinorrhea. 相似文献5.
Randa Osama Kaddah Mohsen Elsayed Khalil 《The Egyptian Journal of Radiology and Nuclear Medicine》2017,48(1):169-178
Objective
To detect the value of MR Arthrography over MRI in evaluation of labral and chondral lesions in all types of FAI, and to correlate the findings with arthroscopy as a gold standard.Patients and methods
50 patients including 33 males and 17 females, age ranges from 19 to 54 years old (mean age 39 ± 5.5), underwent MRI and MR Arthrography of the hip joint followed by arthroscopy correlation. Images were evaluated for labral abnormalities, cartilage and osseous abnormalities associated in FAI. α angle. Acetabular lateral edge angle and degree of focal retroversion were measured.Results
Cam type detected in 20, Mixed type in 28, pincer type in 2, MRI detected 28 labral injury, 51 cartilage affection in 33 cases, MR Arthrography detected 38 labral injury, fraying of the L/C zone in 23 cases, 53 cartilage affection in 33 cases, cam type ch.ch by large α angle, anterosuperior femoral cartilage lesion and osseous bump formation; mixed type include the previous cam findings with a deep acetabulum and posteroinferior cartilage lesions. Anterosuperior labral (AS) tears are more common than postersuperior (PS).Conclusion
Hip MR Arthrography is a faithful evaluation modality for diagnosing the acetabular labral tears, and cartilage abnormalities associated with different types of FAI. 相似文献6.
Samira Saraya Lamia Adel Asmaa Mahmoud 《The Egyptian Journal of Radiology and Nuclear Medicine》2017,48(2):547-552
Objective
To assess the efficiency of dual energy contrast enhanced mammography in the assessment of the indeterminate breast lesions (BIRADS 3 and BIRADS 4).Materials and methods
34 female having 39 indeterminate breast lesions (BIRADS 3 and BIRADS 4) by digital mammography were further examined by dual energy contrast enhanced mammography. Two images were acquired at low and high energy in MLO view after 2 min and in CC view at 4 min post iodinated contrast injection (1.5 ml/kg with flow of 4 ml/s). Images were processed to obtain subtracted images to enhance the areas of the contrast uptake.Results
Results from pathology were detected for all cases. Contrast enhanced digital mammography showed specificity, sensitivity, PPV, NPV, FDR, FPR and accuracy of 93.75%, 91.3%, 88.2%, 95.4%, 11.7%, 8.6% and 92.3% respectively compared to full field digital mammography which were 68.75%, 69.5%, 61.1%, 76.1%, 38.8%, 30% and 69.2% respectively.Conclusion
Contrast-enhanced digital mammography is a useful tool to be used for breast cancer detection especially in indeterminate lesions (BIRADS 3 and 4). 相似文献7.
Ayman Mokhtar Mohamed Elawdy Maysa Abd El-Hamid Huda Refaie Tarek A. El-Diasty Sabry El Mogy 《The Egyptian Journal of Radiology and Nuclear Medicine》2017,48(3):701-705
Objective
To survey computed tomography (CT) radiation dose associated with non-contrast spiral Multislice CT examination in our institute.Methods
Detailed parameters for 362 consecutive examinations, including the patient weight, height, volume CT dose index (CTDIvol), scan length, and dose length product (DLP) were recorded from the dose report. Effective dose (E) was estimated for each patient. The differences between E doses were statistically analyzed using SSPS.Results
Patients body mass index (BMI) was 13.4 to 51.42 (average BMI 29.5 kg/m). Patients dose data (1 scan phase for each patient) from dose information: the median value of DLP was 586.45 mGy cm (83.30–1179.70 mGy cm), median value of CTDIvol was 12.07 (2.20–23.9 mGy), median value of mAs used was 186.50 (34–334 mAs). Effective dose range was (1.1–16.5 mSv) according to international commission of radiological protection (ICRP) 103 and according to ICRP60 the range was (1.3–18.93 mSv). Median value of frequent CT examinations for the same patient was 2 (min 1 scan/year & max 11 scan/year). CT dose variation was highly significant (p value <0.01) depending on high variation on mAs with (r = 0.98). CT dose was moderate depending on BMI (r = 0.55).Conclusion
There was statistically highly significant variation in effective radiation doses associated with non-contrast CT scan of abdomen and pelvis. The reason for this variation must be avoided. 相似文献8.
Mohammad Alaa Abusedera Magdy Khaliel Assem Elsani M.A. Hassan 《The Egyptian Journal of Radiology and Nuclear Medicine》2017,48(1):43-49
Objective
Our aim was to present a single-center experience in the management of gallbladder perforation (GBP).Patients and methods
Adult patients who had GBP were managed surgically and percutaneously. Patients who were high risk surgical candidates or who refused surgery were managed by image guided percutaneous drainage.Results
Thirty-seven patients (21 males, 16 females) with an average age of 64 ± 14 years had GBP. The number of patients with GBP type I, II, and III were 13, 21, and 3, respectively. All GBP types I and III patients were treated surgically. Eleven of GBP type II patients were treated surgically, and 10 were treated by percutaneous catheter drainage. The overall mortality rate was 27% (10/37). No procedure-related mortality rate among those patients who were treated percutaneously; however, 30 days post procedure, the mortality rate was 30%. All of these deaths were related to the patients’ comorbidities; none of them was due to septicemia but conversely in surgically treated patients, 5 died due to septicemia (3 in GBP type I and 2 in GBP type II) in the postoperative period and one patient died because of severe internal hemorrhage complicating acute pancreatitis and one patient died few months later because of myocardial infarction.Conclusion
Surgery is the cornerstone of treatment for all types of GBP. Percutaneous catheter drainage is a safe and effective option for treating patients with localized disease with favorable outcome. 相似文献9.
Susan Adil Ali Maged Abd Elgalil Hamed 《The Egyptian Journal of Radiology and Nuclear Medicine》2017,48(3):671-676
Purpose
to assess the efficacy of FDG PET/CT in detecting unexpected additional primary malignant neoplasms in patients being evaluated by PET/CT for known malignancies compared to conventional staging work-up (CSW).Patients and methods
Of 1889 patients referred for whole-body FDG PET/CT in the period from February 2015 to May 2016, only 273 were included in this prospective study. Patients included are those with histopathologicaly proven primary malignancy and sent for initial tumor staging before treatment within 1 month of CSW that was performed for the patients according to the site and cell type of the primary tumor. Histopathologic examination was performed for lesions indicating additional primary cancer detected by either PET/CT or CSW.Results
In 13 out of 273 patients included in the study (4.76%) only were proved to have additional primary cancer, the PPV of PET/CT for detecting an additional primary cancer was 56.5%. Also, it showed high sensitivity of 89.2%, which was significantly higher than 23% from the CSW (P < 0.005).Conclusion
PET/CT is more accurate than CSW for detecting additional primary cancer with a higher sensitivity and positive predictive value, which consequently affect further management. 相似文献10.
Sherif El-Sayed Mahmoud Hegab Maged Mohamed El-Sayed Eissa Amr Aly Aly Abdel-Kerim Mohamed Said Abel Aziz 《The Egyptian Journal of Radiology and Nuclear Medicine》2017,48(1):133-139
Purpose
This study was done targeting the role of streptokinase injected through pigtail catheter in treatment of pleural empyema in pediatric.Subjects and methods
15 patients were involved in this study of age ranged from 5 months to 15 years were subjected to STK injection once daily until the drainage don’t exceed 100 ml/day and managed by ultrasound guided insertion of pigtail catheter. Broad spectrum antibiotics were given to all patients, after that the antibiotics were adapted according to result of microbial culture because of failed chest tube drainage intrapleural STK is recommended.Results
13 cases show significant improvement, as the total amount of fluid before streptokinase injection was 5 cc in average and significantly rose to 220 cc after streptokinase instillation, while 2 cases do not response to this treatment.Conclusion
Imaging guided streptokinase injected through a pigtail catheter provides a powerful protocol for managing of complicated empyema in pediatrics. 相似文献11.
Objective
The aim of this study was to explore the predictive value of CT enterography-based simple measurement tools for Crohn's disease activity.Patients and methods
During one and half year duration 54 patients diagnosed with CD were retrospectively evaluated. All patients underwent CT enterography examinations following a preset protocol prior to endoscopic biopsy or surgery. The images obtained were reconstructed using dedicated software and workstations. The length of affected segments was calculated (L) and distance from ileocecal junction till first affected segment was measured (D). Results of CTE examinations were compared with histopathology.Results
Out of 54 cases, 38 cases had single segment involvement (70.4%) and 16 cases had multiple affected segments (29.6%). The histological inflammatory activity score scored 1 in 10 cases (18.5%), 2 in 25 cases (46.3%) and 3 in 19 cases (35.2%). L varied from 1.4 cm to 20.6 cm while D varied from 0 to 6.7 cm. Spearman rank order correlation coefficient showed a strong uphill linear relationship of L (RHO = 0.663) and weak correlation of D (RHO = 0.222) with the histological inflammatory activity score.Conclusion
CTE provides accurate data regarding length of affected ileal segments that positively correlated with histopathological score of disease activity. 相似文献12.
Alsiagy A. Salama Reda A. Alarabawy Mohammed M. Dawoud Hanaa A. Zayed Ahmed Soliman Ahmed El-Tantawy 《The Egyptian Journal of Radiology and Nuclear Medicine》2017,48(1):189-199
Objectives
The objectives of our work were to determine disability and study MRI findings of occupational-related lumbar disc degeneration and also to show the relationship between MRI grading of nerve root compromise with surgical grading.Participants and methods
The study included 103 workers with lumbar disc prolapse. Nerve roots were assessed on MRI and during surgery for the degree of compromise. Oswestry Disability Index and Visual Analogue Scale were used for assessment of disability and pain intensity pre- and post-operative respectively.Results
The majority of workers was less than 40 years and suffered from moderate to severe disability. 73.8% had grade IV disc degeneration mostly at the level of L4/L5. Nerve root compromise was found in 86.4% of workers. 48% of nerve roots were deviated and 32% were compressed, with significant correlation between MR grading of nerve root compromise and surgical grading (r = 0.89, P < 0.0001).Conclusion
Disability of occupational-related lumbar disc degeneration is a grave health problem between construction workers. MR imaging is a reliable tool for grading nerve root compromise in disc degeneration. Nerve root compromise is a significant factor to explain pain than the morphologic extension of disc material outside the intervertebral space. 相似文献13.
Ahmed A. Baz Ahmed M. Gad Mohamed R. Waly 《The Egyptian Journal of Radiology and Nuclear Medicine》2017,48(1):125-132
Chronic plantar fasciitis (PF) is, by far, considered one of the commonest causes of foot complaints; constituting up to 15% of the foot symptoms that needs medical care in adult and active subjects.
Purpose
Is to confirm the clinical diagnosis of plantar fasciitis by ultrasound and to depict the effect of ultrasound guided injection of PRP in such cases.Methods
The study was conducted on 44 patients with chronic plantar fasciitis not responding to conservative treatment, they were diagnosed and were treated by ultrasound guided PRP injection then followed-up after 4 months by both clinical and ultrasound examinations.Results
By ultrasound mild improvement in plantar fascia thickness from 6.04 mm (mean of pre injection) to 4.93 mm (mean of 4 months post last injection). By VAS, significant improvement from 8.14 (mean of pre injection) to 2.59 (mean of 4 months post injection). By Roles and Maudsley score, significant improvement from 81.8% of patients who were acceptable and 18.2% were poor (pre injection) to 59.1% became excellent, 31.8% good, 4.5% acceptable and 4.5%poor (4 months post injection).Conclusion
Ultrasound is a confirmatory diagnostic tool of PF and PRP ultrasound guided injection is recommended after failure of conservative treatment. 相似文献14.
Ahmed Elsammak S.M Shehata Mona Abulezz Ghada Gouhar 《The Egyptian Journal of Radiology and Nuclear Medicine》2017,48(3):751-759
Objectives
To assess the role of DW-MRI and ADC values in distinguishing benign from malignant endometrial disorders.Patients and methods
Pelvic ultrasound, conventional MRI, DW-MRI and histopathologic examinations were done for 42 female patients with abnormal vaginal bleeding. Mean ADC values of endometrial lesions were calculated and compared.Results
Endometrial malignancies showed significant low ADC values (0.82 + 1.09 × 10?3 mm2/s) compared to benign lesions (1.44 + 0.15 × 10?3 mm2/s) (p: 0.000). Using 1.19 × 10?3 mm2/s as cut-off value for distinguishing malignant from benign lesions achieved 88.9% sensitivity and 100% specificity.Conclusion
DW-MRI is useful in distinguishing malignant from benign endometrial lesions and tumor staging as well. 相似文献15.
Samira Saraya Rehab El Bakry 《The Egyptian Journal of Radiology and Nuclear Medicine》2017,48(3):687-694
Aim of the study
To evaluate the ultrasound efficiency in the assessment of pneumonia in pediatric age group compared to CT as a trial for radiation exposure reduction.Materials and methods
56 patients of pediatric age group were included (4 months to 10 years). They presented to ER with respiratory distress, and pneumonia was suspected clinically. Human ethics committee approval for this study was obtained from the institutional review board of the private center where these cases were done. Both ultrasound and CT were done for all patients by 2 different radiologists being blind to the results of the other examination to minimize the bias. Follow up US was done after adequate medical treatment (7–14 days) to detect its ability for following the patients up.Results
Ultrasound was able to detect efficiently different pulmonary pathological conditions as consolidation and pleural effusion. Compared to CT, ultrasound showed a sensitivity and specificity of 72.2% and 95% for pneumonia detection respectively with 96.3% PPV, 5% NPV, 3.7% FDR and 80.3% accuracy.Conclusion
Ultrasound could be considered as a good diagnostic and follow up tool when pneumonia especially in pediatric age group is suspected yet well trained radiologists and high resolution equipments are required. 相似文献16.
Mohamed Ahmed Moharram Noha Mohamed Abd-El Maboud Heba A. Elaziz Ahmed 《The Egyptian Journal of Radiology and Nuclear Medicine》2017,48(2):381-391
Purpose
Evaluation of the role of real-time elastography in differentiating between benign and malignant cervical lymph nodes (LNs), comparison with B-mode and Doppler Ultrasonography.Patients and methods
This prospective study included 30 patients, with cervical lymphadenopathy, their age ranged from (18–79 years). The total number of the examined lymph nodes (LNs) was 75 LNs. These (LNs) subjected to B-mode US followed by Doppler evaluation, then elastographic evaluation including strain ratio which was calculated for each lesion, and compared with the histological results after fine needle aspiration cytology.Results
We evaluate the size, shape, echogenicity, and hilum on the B-mode images. The presence of the hilum showed the highest accuracy & sensitivity. Doppler Ultrasonography evaluation of nodal vascular pattern was of high sensitivity & specificity. The calculated sensitivity of elastographic pattern and scoring was 86%, specificity was 100%, PPV and NPV were 100% and 78.1% respectively, and the total accuracy was 90%. The mean elastographic strain ratio for malignant LNs (3.4 ± 1.2) was significantly greater than that for benign LNs (mean, 1.2 ± 0.3).Conclusion
Elastography is a promising improvement for differentiation between benign and malignant cervical lymphadenopathy. Sensitivity and specificity of elastography increased especially if combined with gray scale US and Doppler US. 相似文献17.
Ahmed M. Osman Reham M. Hashim 《The Egyptian Journal of Radiology and Nuclear Medicine》2017,48(1):61-66
Objective
To assess whether the diaphragmatic and lung ultrasound (US) can be used as additive new parameters for the weaning process in intensive care units (ICU) patients in comparison to the traditional weaning parameters.Patients and methods
68 patients were included in our study. All patients admitted inside different ICU units-Ain Shams University for different causes mainly post major surgeries. All patients met the traditional criteria for weaning, had diaphragmatic and lung ultrasound after extubation. We measured the diaphragmatic excursion (E), diaphragmatic thickening fraction (DTF) as well as the degree of lung aeration. All US results were collected and compared with some of usual weaning parameters namely the arterial blood gases as well as respiratory mechanics. The results were statistically analyzed.Results
50 patients showed successful weaning process. Diaphragmatic E and TF showed high sensitivity and specificity in correlation with the other parameters. The cut off value was 10 mm for the E and 28% for the DTF and 12 for the lung US. A score was put to predict the outcome of weaning process.Conclusion
For the patients undergoing weaning process, diaphragmatic and lung ultrasound can be used as additive new parameters for prediction of weaning process outcome. 相似文献18.
Mohamad H. Abowarda Hossam M. Abdel-Rahman Mahmoud M. Taha 《The Egyptian Journal of Radiology and Nuclear Medicine》2017,48(1):207-213
Aim
To evaluate the role of using a single shot spin echoplanar DW sequence (SSSEP-DWI) compared to conventional MRI and contrast enhanced T1WI in differentiation between vertebral osteoporotic fractures and malignant compression fractures. The sensitivity and specificity of (SSSEP-DWI) will also be calculated.Patients and methods
Sixty-eight acute vertebral compression fractures in 41 patients were imaged using conventional MRI, fat suppressed contrast enhanced T1WI and DW sequence on a 1.5 T MR machine. Quantitative assessment of the abnormal signal intensity was done by measuring apparent diffusion coefficients (ADCs). Also, the areas of abnormal signal intensity were compared to adjacent normal marrow.Results
We had 38 benign fractures, and 30 malignant fractures. Post contrast enhancement showed sensitivity of 92% and specificity of 70% for malignant compression fractures. The hyperintense signal on DWI has 89% PPV for malignancy, while the sensitivity and specificity were 86% and 91% respectively. The mean ADC for malignant fractures was significantly lower than those of osteoporotic fractures (p = 0.0002).Conclusions
SSSEP-DWI is a reliable adjunct parameter that supports conventional MRI in differentiating benign and malignant vertebral fractures. 相似文献19.
Mona El-Kalioubie Wessam Abdelrahman Elzayat Hassan Ali El-kiki Mohamed Alaa Eldin Thabit 《The Egyptian Journal of Radiology and Nuclear Medicine》2017,48(3):695-700
Purpose
The aim was to evaluate post-operative changes in the Ivy sign on unenhanced fluid-attenuated inversion-recovery (FLAIR) following surgical intervention in pediatric Moyamoya disease (MMD) and assess its clinical utility as an indicator of hemodynamic improvement.Patients and methods
Fifteen pediatric patients with MMD were included in this retrospective study. Surgical revascularization had been done in all patients on the cerebral hemisphere with reduced cerebral vascular reserve (CVR); one of them had bilateral surgery (n = 16). FLAIR examinations were reviewed in each patient, pre and post-operative. We compared the pre and post-operative total Ivy score (TIS) for each of the 16 hemispheres and correlated them with the clinical status.Results
FLAIR images depicted the Ivy sign pre-operatively in all 16 hemispheres and a strong positive correlation between the TIS and the grade of clinical hemispheric symptom (p < 0.00001). Following surgery, reduction of the TIS was seen in 13 (81.25%) out of the 16 hemispheres while the TIS remained unchanged in 3 (18.75%) hemispheres. All patients with reduced Ivy signs post-operatively showed improvement of pre-operative clinical symptoms with moderate positive correlation (p = 0.01).Conclusion
A change in the postoperative Ivy sign can be an indicator of effective cerebral reperfusion in MMD. 相似文献20.
Ahmad Hafez Ahmad Afifi Eman Mohamad Ahmad Ashraf Naguib Etaby Mohamad Adel Atta Sherif Farouk Elzawawi 《The Egyptian Journal of Radiology and Nuclear Medicine》2017,48(3):677-685