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Objective:To explore the value of size-specific dose estimate (SSDE) based on effective diameter and water equivalent diameter ( Dw) in pediatric head CT. Methods:A retrospective analysis of 187 children underwent unenhanced head CT scanning were reviewed and divided into 3 groups according to the age: Group 1 (<1 m), Group 2(≥1 m~6 y), Group 3 (≥6~14 y). All CTDI vol values were recorded. The central axial image in the scanning range was selected. The region of interest (ROI) containing all anatomical structures (including skin) was outlined and the area of ROI ( AROI), head circumference, average CT value (CT ROI) were measured. The Dw, conversion factor fH16 and SSDE were calculated. The CTDI vol, SSDE and the rate of change( Δvalue)were compared among groups. The regression model between CTDI vol and SSDE was established. Results:The Dw values of groups 1-3 were (11.24±0.51), (14.48±1.47), (16.69±0.90)mm, respectively. The CTDI vol values were(15.36±2.78), (18.83±4.60), (23.24±4.13)mGy, respectively. SSDE values were(27.92±4.91), (29.16±6.64), (32.38±5.35)mGy, respectively. The differences among Dw, CTDI vol and SSDE groups were all statistically significant ( F=207.69、38.48、8.15, P<0.001). The values of Dw, CTDI vol and SSDE were gradually increasing while the age was increasing. However, the Δ value gradually was decreasing with increasing age. The linear regression equation of CTDI vol and SSDE was established as SSDE=7.252 + 1.137×CTDI vol. Conclusions:The radiation dose of children′s head CT can be accurately assessed based on Dw combined with head conversion factor fH16 to estimate the body-specific dose SSDE. The radiation dose of children′s head CT was underestimated with the greater degree for smaller age.
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Objective:To analyze the pulmonary high resolution CT (HRCT) images before and after hematopoietic stem cell transplantation (HSCT) in 6 children with Niemann-Pick disease(NPD) type B, and to investigate the effect of HSCT on lung lesions.Methods:Data of 6 children who were diagnosed with NPD type B and underwent HSCT treatment in Children′s Hospital Affiliated to Capital Institute of Pediatric from March 2019 to June 2021 were retrospectively enrolled, including 5 males and 1 female, with ages ranging from 1 year and 2 months to 5 years, and a median age of 2 years and 1month. The follow-up time of HRCT after HSCT was 7-20.5 months, the median time was 5 months, and the number of follow-up was 2-7 per patients, a total of 27 times. The pulmonary lesions (including interstitial lung disease, airway lesions and alveolar lesions) on aortic arch level, tracheal carina level and right diaphragmatic surface level were evaluated and scored respectively by two experienced pediatric radiologists, and the average score between them would be the final score. The Kruskal-Wallis H test was used to compare the scores of the three kinds of lung lesions before HSCT. The linear regression method was used to analyze the impact of HSCT duration on the degree of different lesions. To control possible confounding factors in the study, a generalized linear mixed model was used to evaluate the effects of HSCT duration, age, gender and whether co-infection on different types of lesions after HSCT. Results:Before HSCT treatment, all of the 6 children had different degree of airway, interstitial and alveolar lesions, with a median score of 3.0, 14.0 and 5.8 points, respectively (χ2=11.95, P=0.003). Interstitial disease was the most extensive and serious lesion among those three pulmonary involvements in pediatric NPD type B. After HSCT treatment, the scores of interstitial and airway lesions in all of the 6 children reduced, in varying degree, with the increase of time after HSCT. Except case 4, the alveolar lesion in 5 patients also showed a decreasing trend over time. The linear regression equation between the score of airway, interstitial, alveolar lesions and the HSCT duration was: airway lesion, Y=1.94-0.15X; interstitial lesion, Y=12.73-0.78X; and alveolar lesion, Y=3.31-0.27X. The results of the generalized linear mixed model showed that the main effect of HSCT duration significantly affected on the three kinds of lung lesions, and the scores of interstitial lesions, airway lesions and alveolar lesions were decreased by 0.688, 0.245, and 0.338 points for each 1 month increase of HSCT duration (all P<0.05). The alveolar lesion score decreased by 1.135 points for each 1 year increase in age at presentation ( P=0.012). The main effects of gender and co-infection were not statistically significant in all of the pulmonary lesions (both P>0.05). Conclusion:HSCT alleviates pulmonary lesions of children with NPD type B significantly and consistently, with interstitial lesions were the most prominent.
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Objective:To explore the CT features of benign and malignant thymus diseases in order to improve the diagnostic accuracy of thymus diseases in children.Methods:The clinical data and imaging data of children with thymic diseases who underwent CT examination in children′s Hospital Affiliated to Capital Institute of Pediatrics from August 2014 to may 2019 were retrospectively analyzed. There were 32 males and 18 females with an average age of (6±4) years (range 5 days to 14.2 years). According to the clinical diagnosis and/or pathological results, all children were divided into benign group (22 cases) and malignant group (28 cases). The clinical manifestations and CT signs (thymus volume, shape, border, density, internal characteristics, relationship with surrounding structures, enhancement pattern and extent) of benign group and malignant group were summarized and compared.Results:The clinical manifestations of benign group and malignant group were varied, and fever was the most common sign. In the benign group, 8 cases showed thymus deficiency, all of them were diagnosed as primary immunodeficiency disease, and the clinical manifestations were repeated and persistent respiratory tract infection history. In 28 cases of malignant group, 20 cases had peripheral invasion and distant metastasis, including 7 cases of lymph node, 6 cases of pleura, 6 cases of lung, 2 cases of pericardium, 2 cases of liver, 2 cases of spleen, 2 cases of kidney and 1 case of bone. All 6 cases of pleural involvement occurred in children with non Hodgkin′s lymphoma. There were significant differences in CT findings between the two groups ( P<0.05); there were no significant differences in terms of shape, density, internal calcification or cystic change, enhancement pattern and enhancement extent of thymus lesions between the two groups ( P>0.05). Conclusions:Benign lesions of thymus usually manifests as absence or normal size of thymus, well-defined, non-necrotic, no displacement of vessels, no peripheral or distant invasion on CT; whereas malignant lesions are mostly enlarged, well or ill-defined, with internal necrosis and vessel displacement, surrounding or distant invasion. CT manifestations of benign and malignant thymus diseases have featured characteristics, and the combination of clinical manifestations is helpful for the differential diagnosis.
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Objective:To explore the imaging manifestation and the value of imaging follow-up in Takayasu arteritis with pulmonary artery involvement in children.Methods:The data of Takayasu arteritis with pulmonary artery involvement in 7 children in Children Hospital, Capital Institute of Pediatrics from July 2014 to June 2019, were summarized retrospectively, including 1 boy and 6 girls. There were 6 children under 1 year old, the age ranged from 2 to 7 months and the median age was 3 months old. Another child was 12 years old. CT images of all cases in the initial diagnosis and during the follow-up were reconstructed. The diameters and wall thickness of arteries were observed, including ascending aorta, main pulmonary artery, left and right pulmonary artery and each lobe pulmonary artery. The diameter ratio of main pulmonary artery to ascending aorta (MPA/AAO) was calculated. The pulmonary artery pressure, the diameters of left and right coronary artery were measured using echocardiography and compared in the initial diagnosis and during the follow-up.Results:All the 7 cases showed main pulmonary artery, left and right pulmonary artery widened, 6 cases showed lobe pulmonary arteries widened, 2 cases showed main pulmonary artery, left and right pulmonary artery wall thickened, and 6 cases showed lobe pulmonary arteries wall thickened. All the 7 cases showed MPA/AAO>1 in the initial diagnosis, but only 1 case (12-year-old girl) presented pulmonary hypertension from echocardiography. All the 7 cases showed coronary artery dilated in different degrees and ranges in the initial diagnosis, including 3 cases with bilateral coronary artery dilatation and 4 unilaterally. Five children were followed up and showed improvement of pulmonary artery dilatation in 4 cases and progress in 1 case. MPA/AAO decreased in 4 cases and increased in 1 case. The pulmonary hypertension of the 12-year-old patient decreased during the follow-up, and the MPA/AAO also decreased from 1.64 to 1.01. Coronary artery dilatation decreased in 4 of 5 cases during the follow-up.Conclusion:CT imaging can clearly show pulmonary arteries, which plays an important role in the diagnosis and assessment of the treatment effect in Takayasu arteritis with pulmonary artery involvement in children.
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Objective To summarize the MRI manifestations of immunosuppressive drugs associated encephalopathy after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in children with aplastic anemia. Methods Fifteen patients with immunosuppressive drugs associated encephalopathy after allogeneic hematopoietic stem cell transplantation for aplastic anemia during January 2014 to October 2016 were analyzed retrospectively. There were 7 males and 8 females, aged from 3 to15 years old, with the median age of 7 years old. Ten cases presented dizziness and headache while other 4 cases presented blurred vision, blind and gaze. Only one case suffered from seizure and loss of consciousness. MRI patterns including distribution, morphology and signal intensity were analyzed after treatment. Follow up MRI were performed after reducing drug dose and symptom remission. The duration of immunosuppressive drugs associated encephalopathy of the 15 cases were 1-14 months, with 6 months in 9 cases. Results Focal lesions were found in 11 cases, in which the deep nuclei were involved in one case and the white matter was involved in 10. Four patients showed both cerebral cortex and white matter lesions, including cerebellum and brainstem invasion in one patient. No corpus callosum lesions were found. Various degree of brain atrophy was found in all patients. Cortical lesions showed swelling and involved subcortical white matter presented as arc shape or strip-like lesions. Patchy patterns were found in deep white matter. Thin layer shaped lesions were found in the periventricular white matter. Small flake-like lesions were found in the brain stem and the cerebellum. The lesions showed hypointensity on T1WI, equal or high signal on T2WI. T2WI FLAIR showed equal or high signal;DWI in the cortex and subcortical white matter lesions showed iso-or high signal, while other lesions were isointense. Eight cases acquired clinical relief in short term without obvious improvement on MRI image. Both clinical symptoms and imaging findings improved in 6 cases. One case showed clinical relief but progression on MRI. Conclusions MRI is an effective way to find immunosuppressive drugs-related encephalopathy in children with aplastic anemia after allogeneic hematopoietic stem cell transplantation. It can help the diagnosis and provide the information for clinical treatment.
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Objective To summarize the MRI manifestations of immunosuppressive drugs associated encephalopathy after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in children with aplastic anemia. Methods Fifteen patients with immunosuppressive drugs associated encephalopathy after allogeneic hematopoietic stem cell transplantation for aplastic anemia during January 2014 to October 2016 were analyzed retrospectively. There were 7 males and 8 females, aged from 3 to15 years old, with the median age of 7 years old. Ten cases presented dizziness and headache while other 4 cases presented blurred vision, blind and gaze. Only one case suffered from seizure and loss of consciousness. MRI patterns including distribution, morphology and signal intensity were analyzed after treatment. Follow up MRI were performed after reducing drug dose and symptom remission. The duration of immunosuppressive drugs associated encephalopathy of the 15 cases were 1-14 months, with 6 months in 9 cases. Results Focal lesions were found in 11 cases, in which the deep nuclei were involved in one case and the white matter was involved in 10. Four patients showed both cerebral cortex and white matter lesions, including cerebellum and brainstem invasion in one patient. No corpus callosum lesions were found. Various degree of brain atrophy was found in all patients. Cortical lesions showed swelling and involved subcortical white matter presented as arc shape or strip-like lesions. Patchy patterns were found in deep white matter. Thin layer shaped lesions were found in the periventricular white matter. Small flake-like lesions were found in the brain stem and the cerebellum. The lesions showed hypointensity on T1WI, equal or high signal on T2WI. T2WI FLAIR showed equal or high signal;DWI in the cortex and subcortical white matter lesions showed iso-or high signal, while other lesions were isointense. Eight cases acquired clinical relief in short term without obvious improvement on MRI image. Both clinical symptoms and imaging findings improved in 6 cases. One case showed clinical relief but progression on MRI. Conclusions MRI is an effective way to find immunosuppressive drugs-related encephalopathy in children with aplastic anemia after allogeneic hematopoietic stem cell transplantation. It can help the diagnosis and provide the information for clinical treatment.
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Objective To explore the CT findings of pediatric hepatoblastoma and its correlation with pathological subtypes.Methods CT findings and pathological characteristics of 110 patients with hepatoblastoma confirmed by pathology were retrospectively analyzed.Results The locations of the tumor were right lobe (67/110,60.90％),right and left lobe (25/110,22.72％),left lobe (15/110,13.63％) and caudate lobe (3/110,2.72％).The average tumor size was (287.14±272.36) cm3.Most cases were solitary (94/110,85.45％) and round shape (96/110,87.27％).Most cases were well defined (86/110,78.18 ％).Necrosis were irregular in 102 cases,calcification were in 60 cases.Lung metastases were common (23/110,20.90 ％) and vessel involvement were common (56/110,50.90 ％).Lymph node metastasis was in 5 cases.Calcification and homogeneous enhancement in different pathological types had statistically significance (both P ＜0.001).Conclusion CT is helpful for pre-operation and pathological diagnose.
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Objective To compare the CT findings of different phases in pediatric hepatoblastoma (HB) based on PRETEXT system in order to optimize pediatric HB CT scan protocol. Methods A total of 58 HB patients who were surgical and pathological diagnosed from January 2015 to December 2016 were analyzed. Pre-operation CT exams were analyzed respectively. Observing items included tumor size, intra-abdominal invasion, bleeding, intrahepatic metastasis, lymphatic metastasis, metastasis (except lymphatic in abdomen) main portal vein, three main hepatic vein, inferior vena cava (IVC) invasion, para-tumor hepatic arteries, and its branches. All image findings were compared to pathological and surgical findings to calculate the agreement rate. Exact Fisher test and R × C χ2 test were used. Results According to the surgery and pathological results, the agreement rate of tumor size was n=40 (68.9%) at non-contrast phase, n=43 (74.1%) at artery phase and n=52 (91.2%) at venous phase. Venous phase was adaptive for observing tumor size (χ2=8.16,P=0.018). For main portal vein, three main hepatic vein, and IVC invasion, none was found at both non-contrast and artery phase. N=12 (20.7%, P<0.001) was found at venous phase. For para-tumor hepatic arteries, and its branches, none was found at non-contrast phase. N=46 (79.3%) was found at artery phase. N=17 (29.3%) was found at venous phase. Artery phase was adaptive for observing (P<0.001). There was no statistical significant difference in intrahepatic metastasis, lymphatic metastasis and metastasis. Conclusions Suspected pediatric HB, artery and venous phase CT scan would meet the clinical requirement, there was no need for non-contrast pahse. Follow up cases, a single venous phase was enough. Venous phase contributed much more information on tumor size and high risk prognosis evaluation.
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Objective To optimize the exposure parameters and reduce the irradiation dose level in infants and young children during digital radiography (DR) chest radiography under the premise of satisfied image quality.Methods The thoracic thickness of 100 patients were measured.Determined the aluminum equivalent of the thoraxes of the infants and young children by comparing the grayscale value and the aluminum step wedge.Another 100 infants and young children of experimental exposure were performed with the aluminum step wedge as a phantom,under AEC control,kV was the only variant to explore the optimal exposure parameters with dose monitor simultaneously.At last,clinical validation was performed.Images quality was compared with x2 test.The radiation dose of two groups was compared with t test.Results The maximum,minimum,average thoracic thickness and their correspondent aluminum equivalent were 13.5 and 2.3 cm,8.0 and 1.4 cm,(10.6 ± 1.3) and 2.0 cm,respectively.The average thoracic thickness of experimental group was (10.1 ± 2.2) cm.The range of entrance surface dose was 0.068-0.056 mGy while the tube voltage range was 55-65 kV.The exposure index range was 0.60-0.74.The visual inspection of aluminum step wedge was from grades 8 to 11 with satisfying image quality at lower radiation.The infant chest X-ray photography exposure parameters formula have been optimized,that was kV =thoracic thickness (cm) × 2 + 38 (constant),mAs (0.8-1.0) with SID =100 cm,without filter grid.Compare to the conventional parameters,the image quality of new method had no significant differences (P ＞ 0.05).The actual average entrance surface dose was (0.048 ± 0.007) mGy,lower than AEC group (0.066 ± 0.008) mGy.The difference was statistically significant (t =16.781,P ＜ 0.001).Conclusions The optimized formula kV =thoracic thickness (cm) ×2 + 38(constant),mAs (0.8-1.0) with SID =100 cm was credible for lowering the radiation exposure with good image quality for clinical diagnosis.
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Objective To summarize the lung HRCT findings of lung Langerhans cell histiocytosis (LCH) in children. Methods A total of 54 children with lung LCH pathologically proved in our institute from September 2006 to December 2014 were retrospectively reviewed. Patients were subdivided into two subgroups, diffuse type (n=29) and localized type (n=25). In addition, 32 children with LCH but without pulmonary infiltration were selected as control group. HRCT findings of 54 LCH with lung involvement were reviewed and analyzed for distribution pattern. The age of onset, illness duration and pulmonary function were compared between the lung LCH group and the control group. The differences of HRCT findings in LCH patients between diffuse type and localized type were compared with χ2 test. The differences on the onset age, illness duration and pulmonary function between the LCH group with lung involvement and control group were compared with non-parametric test(Mann-Whitney U Test). The differences of pulmonary function between the LCH group with lung involvement and control group were compared with Fisher exact probability test. Results The signs of pulmonary LCH on HRCT included lobular hyperinflation (n=26), interlobular septa thickening (n=11), cystic lesions (n=11), ground?glass opacity (n=10), nodules (n=9), and centrilobular nodules (n=6). The signs presented in 21, 8, 7, 9, 4 and 6 cases in diffuse type group respectively and 5, 3, 4, 1, 5, 0 in localized type group. Among them, lobular hyperinflation, ground?glass opacity and centrilobular nodules were more prevalent in the diffuse group. The difference was statistically significant (χ2=14.77,2.01,0.55,4.84,0.06 and 3.91, P0.05) and pulmonary function between two groups (P>0.05). Conclusions Lobular hyperinflation, ground glass opacity and centrilobular nodules are the most common manifestations in LCH patients with lung involvement and the distribution is mostly diffuse. Nodules, cystic lesions and interlobular septa thickening may exist. Several signs may coexist simultaneously. Younger children with LCH are more vulnerable to lung involvement.
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Objective To measure the average value of CT lung density at the phase of end inspiration and end expiration in children under 5 years.Methods Sixty patients with normal lungs who underwent chest CT for reasons caused by trauma etc.in our institute from January 2010 to March 2012 were enrolled to the study.All of the patients were divided into end inspiration group and end expiration group through random number table.CT images of the phase of end inspiration and end expiration were taken.Three levels of CT images were chosen to measure the lung density,which were 2 cm above the arch,1 cm below the carina and 2 cm above diaphragm.Lung density was measured at anterior,posterior,lateral,medial and central of the images at each level in each lung.The average lung density of each and entire lung were respectively calculated.The influence of phase,level,location was quantified using analysis of variance methods and LSD method.Results The average lung density at end inspiration was (-766 ±56)HU for the left,right and both lung.At end expiration,the average lung density of the left,right and both lungs was (-625 ± 86),(-647 ± 85) and (-636 ± 86) HU respectively.The average densities at anterior,posterior,lateral,medial and central of the left lung at end inspiration were (-798±63),(-733±68),(-767±64),(-754 ±65),(-775 ±63)HU respectively.The average densities at anterior,posterior,lateral,medial and central of the right lung were (-796 ± 70),(-736 ± 65),(-769 ± 64),(-754 ± 62),(-776-± 59) HU respectively.At end expiration phase,the average densities at anterior,posterior,lateral,medial and central of the left lung were (-692±91),(-555±116),(-639±91),(-598±103),(-640±98) HU respectively.The average densities at anterior,posterior,lateral,medial and central of the right lung were (-712 ± 90),(-575±121),(-657±90),(-619±95),(-670±87) HU respectively.The statistical differences of these five measurement areas were significant at both inspiration and expiration phase (F=12.55,11.29,23.31,25.47,P＜0.01).The posterior lung density was the highest and the anterior was the lowest.As for the other measurement areas,in descending order were medial,lateral,and central.Conclusion The lung density at end inspiration and end expiration in children under 5 years old is described to provide reference for the clinical work.
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Objective To semi-quantitatively assess the MRI manifestations of knee in patients with juvenile idiopathic arthritis (JIA) and to explore the relationship between the semi-quantitative scores with clinical inflammatory biomarkers. Methods Fifty children diagnosed as JIA and presented with knee pain, swelling or limitation were enrolled and their clinical and imaging findings were retrospectively analyzed. Contrast-enhanced MRI scan of the knee were performed in all cases (a total of 50 knees). MRI abnormalities, including synovial hypertrophy, joint effusion, bone marrow edema, joint cartilage injury and bone erosion, were assessed with a semi-quantitative score system. The erythrocyte sedimentation rate (ESR) and C reactive protein (CRP) at the same period with MRI were collected. The relationships between the MRI scores and laboratory biomarkers (CRP and ESR) were analyzed with Spearman correlation analysis. Results In MR images of all the 50 knees with JIA, synovial hypertrophy(43, 86%)and joint effusion(40, 80%)were major abnormalities, bone marrow edema was seen in 6 knees, joint cartilage injury in 12 knees and no bone erosion was seen. The scores of synovial hypertrophy, joint effusion, marrow edema, joint cartilage injury and bone erosion were 7(0-12), 3(0-7), 0(0-6), 0(0-10), 0, respectively. There was significant correlation between synovial hypertrophy and joint effusion(r=0.719, P=0.001). There were positive relationship between synovial hypertrophy and ESR and CRP(r=0.306 and 0.285; P=0.031 and 0.043, respectively).Other indexes had no significant relationship with ESR or CRP. Conclusions MRI could comprehensively evaluate knee involvement in patients with JIA. Joint effusion could be a useful reference to evaluate the condition of synovitis for pediatric patients with non-enhanced MR images.
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Objective To explore the clinical value of multi-slice CT in distinguishing between benign parotid tumors and malignant parotid tumors. Methods CT scanning images of 72 parotid tumor patients were analyzed. The location, shape, density, edge, cystic necrosis and degree of enhancement of the tumors were analyzed, de-gree of cervical lymph node swelling were analyzed, and all the analysis results were compared to pathological re-sults. Results 80 lesions were diagnosed in tumors, among which 59(73. 8%) lesions were benign tumors and 21 (26. 2%) lesions were malignant tumors. The CT images of benign tumors showed that 42(71. 2%) of them were located in the superficial lobe and with regular shape and uniform density;62.7% of them had clear edge;57 . 6%of them showed mild or moderate enhancement. 2 cases of benign tumors presented cervical lymph node swelling, which were proved to be pathological inflammatory mass after operation. Whereas in the CT images of malignant tumors 12( 57. 1%) of them were located in the deep lobe or in both of the superficial lobe and the deep lobe. 15 (71. 4%) of them had irregular shape and uneven density. 81% of them had unclear edge. 71. 4% of malignant tumors were significantly enhanced. 9 cases of malignant tumor were with cervical lymph node metastasis. There was statistical difference between the shape, edge, density, cystic necrosis, degree of enhancement and cervical lymph node metastasis of the two groups of tumors(P0.05 ) . Conclusion Most of benign and malignant parotid tumors can be correctly diagnosed by analyzing multi-slice CT images.
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<p><b>OBJECTIVE</b>To assess the effects of 1-step method of changing the buccal position of the transported bone after distraction on early bone formation.</p><p><b>METHODS</b>The custom-made bidirectional distraction devices were used. Total of 8 adult mongrel dogs were procured. The bilaterally mandible premolars were extracted. After 1 month, the complete osteotomy was performed and the devices were placed. The gradual distraction was started after 1 week latency at the rate of 1 mm per day, total 6 mm in height was achieved. The 1-step method of changing the buccal position of the transported bone was performed the day after the vertical distraction period in one side of the animals, and the other side as the controlled side. All animals were killed after a 7 days consolidation. The vascular system was stained post mortem carbon ink perfusion to assess possible damages. Quantitative evaluations of bone density were performed with dual-energy X-ray absorptiometry (DEXA), analysis of the ratio of vascular square was conducted in a computer.</p><p><b>RESULTS</b>All animals tolerated the procedures well. After vertical distraction, the tested side can be moved 3 mm in buccal direction. DEXA examination showed that the density of the distracted bone was no statistical difference in both the tested and the controlled side. Vascular damage was not observed, and there was no statistical difference in the ratio of vascular square by analyzing the histological section in computer.</p><p><b>CONCLUSION</b>In some extent, 1-step method of changing the buccal position of the transported bone after distraction can mold the regenerate bone to correct the axial displacement, without endangering early callus formation and vascularization.</p>
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Animals , Dogs , Bone Density , Bone Regeneration , Bone and Bones , Mandible , Osteogenesis , Osteogenesis, DistractionABSTRACT
Objective:To analyze the value of fine needle aspiration cytology and CT perfusion imaging in differential diagnosis of benign and malignant salivary gland tumors. Methods: Perfusion CT and fine needle aspiration cytology were performed in 36 patients of salivary gland tumors(26 cases in parotid gland, 8 cases in submandibular, 1 case in sublingual gland and 1 case in pars palatalis) and perfusion parameters, including: blood flow(BF), blood volume(BV), mean transit time(MTT), permeability surface(PS). Pathological diagnosis was performed on all salivary gland tumors. Results: 13 cases of 36 patients eventually were diagnosed as malignant salivary gland tumors. The sensitivity, specificity and accordance rate for malignancy of fine needle aspiration cytology were 84.6%(11/13), 95.7%(22/23) and 91.7%(33/36), respectively. The values of BF, BV and PS of the malignant tumors were higher than those of benign tumors significantly(P<0.05). However, the MTT values showed no significant difference between benign and malignant tumors(P>0.05).The sensitivity, specificity, and accordance rate for malignancy of CT perfusion were 92.3%(12/13), 86.9%(20/23) and 88.9%(32/36), respectively. The negative cases of fine needle aspiration cytology can be correctly identified as malignant by CT perfusion imaging. Conclusion: CT perfusion imaging can provide salivary gland tumors with information of microcirculation perfusion. It contributes to the identification of benign and malignant tumors. Paralled with fine needle aspiration cytology can greatly improve the accuracy of salivary gland tumors.
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It is necessary to have a research on dental fluorosis in a population to minimize the prevalence and severity of caries.It is important to research the pathogenesis of enamel fluorosis and prevention and control of dental fluorosis and caries.This article reviews the progress in chemistry and biology of dental fluorosis.
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It is imperative for hospital administrators to make unremitting efforts to control medical quality, the most important aspect of hospital management. The authors give an account of the specific plans and measures for setting up the framework of whole process control of medical quality and put forward some suggestions for dealing with the results of medical quality control and assessment. They also sum up their experience as follows: ①attention by the leading group constitutes the fundamental guarantee of medical quality improvement; ②social supervision may spur medical workers to take initiatives in standardizing their medical behavior; ③making full use of the results of assessment is the key to quality control.
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0.05).Conclusion:The CT perfusion parameters can be regarded as a surrogate marker of tumor angiogenic activity,which is a useful method in estimating the degree of angiogenesis.