ABSTRACT
<p><b>OBJECTIVE</b>To evaluate the findings of computed tomography (CT) as objective markers of bone remodeling in rabbit models with chronic rhinosinusitis.</p><p><b>METHODS</b>Forty-eight rabbit models were established by vaccination of staphylococcus aureus. The rabbits were divided into 3 groups according to the time of infection: group A, B and C (4, 8, 12 weeks after infection), 16 rabbits in each group. Each group was subdivided into the medication administration team and the control team, 8 rabbits in each team. All the rabbits were examined by CT before vaccination to rule out the disease of nasal cavity and sinuses, and the CT images were used as the negative control. No interference was given to the control teams which were only examined again by CT when reached the end week. Dexamethasone sodium phosphate were administered to the medication administration teams 2 weeks before the end of experiment, and were examined by CT at the end. The images of both horizontal position and coronal position by reconstruction were obtained. The Hounsfield unit (Hu) of the bone which was the thickest position in each image were measured. The data was analyzed by SPSS 16.0 software. The Hu was analyzed statistically to compare the situation of the bone remodeling in different periods and administration in the rabbit models with CRS.</p><p><b>RESULTS</b>Average Hu (x±s) of normal rabbits was 810.0±99.7, average Hu at the end time: control team in group A was 964.0±84.6, medication administration team in group A was 833.0±92.5; control team in group B was 987.0±91.5, medication administration team in group B was 886.0±91.6; control team in group C was 1086.0±74.0, medication administration team in group C was 899.8±76.5. The Hu in all groups were higher than normal (t value were 2.747, 4.513 and 7.350 respectively, all P<0.05). No statistical difference was found between control teams of group A and B (t=0.423, P=0.667). The Hu in control team of group C was higher than group B (t=3.905, P=0.001); There was no statistical difference between medication administration teams of group A and B (t=0.892, P=0.384), and group B and C (t=0.886, P=0.385). The Hu of all medication administration teams in 3 groups were lower than all the control teams (t value were 2.717, 3.687, 8.379 respectively, all P<0.05).</p><p><b>CONCLUSIONS</b>Bone remodeling was found in rabbit models with rhinosinusitis, and the phenomenon was more obvious if the period was lengthened. The Hu could reflect the degree of bone remodelling. Glucocorticoids could depress the bone remodeling in the rabbit models with rhinosinusitis.</p>
Subject(s)
Animals , Rabbits , Bone Remodeling , Disease Models, Animal , Nasal Bone , Diagnostic Imaging , Nasal Cavity , Sinusitis , Diagnostic Imaging , Microbiology , Tomography, X-Ray ComputedABSTRACT
Objective To evaluate the diagnostic value of conventional and dynamic contrast- enhanced MRI in lymphoma of the orbit.Methods Thirteen cases of lymphoma of the orbit,including B-C (10 cases),T-C (1 case),T-NK-C (1 case)lymphoma,and multiple myeloma (1 case),were studied using conventional MR and dynamic contrast-enhanced MR imaging with 3D fast spoiled gradient echo sequence.Calculated values included time to peak (Tpeak),washout ratio (WR),slope and enhancement ratio (ER),and time-intensity curves (TICs),and Tpeak,WR,slope and ER were calculated preoperatively.Results Eleven of the 13 lymphomas of the orbit was seen in the anterior portion of the orbit including eyelid and lacrimal gland.On conventional MRI,10 cases showed iso-intensity on T_1WI and T_2WI and all 13 cases showed moderate enhancement after contrast administration.TIC of all 13 cases showed rapid enhancing and wash-out,Tpeak was (58.7?8.5)s,and WR was (30.9?9.4)%.The accurate diagnosis with only conventional MRI was achieved in 6 out of 13 cases,while the accurate diagnosis was achieved in all 13 cases by using combined conventional MRI and dynamic enhanment MRI.Conclusion onventional MRI combined with dynamic contrast-enhanced MRI is useful for the diagnosis of lymphoma of the orbit.
ABSTRACT
Objective To analyse the characteristics of orbital benign and malignant masses on diffusion weighted imaging in combination with conventional MR imaging and evaluate the diagnostic value of apparent diffusion coefficient in distinguishing benign and malignant orbital lesions.Methods Seventy- seven cases with orbital masses,including fifty-five benign lesions and twenty-two malignant tumors,who underwent conventional MRI and diffusion imaging scanning were studied with use of a 1.5 T magnetic resonance system.Quantitative ADC measurements of masses(ADC_M)and of the white matter of eontralateral temporal lobe(ADC_W)were made with two different b-values of 0 and 1000 s/mm~2.The ADC ratio(ADCR)of the lesion to the control was calculated.The receiver operating characteristic curves(ROC) were constructed using various cut points of ADC_M and ADCR for different parameters to differentiate between benign and malignant masses.The area under the ROC curve for each parameter was also calculated. Results All cases were proved by histopathology.The mean ADC_M and ADCR of benign orbital masses were(1.56?0.75)?10~(-3)mm~2/s and 1.85?0.91,respectively.The mean ADC_M and ADCR of malignant orbital masses were(1.09?0.42)?10~(-3)mm~2/s and 1.28?0.53,respectively.There were significant difference both between ADC_M and ADCR of benign and malignant masses(t=2.803,2.735,P