ABSTRACT
Objective To assess the value of apparent diffusion coefficient (ADC)map with low b-value to monitor the ablated tissue after high-intensity focused ultrasonic (HIFU)treatment for uterine fibroids.Methods 25 patients with 34 uterine fibroids were treated with HIFU.All patients underwent the routine MRI scans (including pre-and post-contrast scanning)and monoexponential model DWI with b values of 150,600 and 1 000 s/mm2 before the surgery and within 24 hours after the surgery.The mean ADC values with different b-values of the ablated and non-ablated tissues between pre-and post-treatment were analyzed by one-way ANOVA test.The consistency of the ablation area between ADC maps with different b-values and contrast enhancement MRI were evaluated. Results With the b-value of 150 s/mm2 ,the mean ADC value of the ablated tissue was (1.48±0.27)×10-3 mm2/s,which was less significantly than that of pre-treatment (2.06±0.21)×10-3 mm2/s and non-ablated tissue (1.98±0.23)×10-3 mm2/s (P0.05).A fine consistency of the ADC map with the low b-value (150 s/mm2 )was found with non-perfusion volume on contrast-enhanced T1 WI,which was superior to that with high b-values (600 s/mm2 and 1 000 s/mm2 )(P<0.05).Conclusion ADC map with low b-value (150 s/mm2 )can be used to evaluate the blood-supply changes and ablated volume of uterine fibroids indirectly,which helps to assess the treatment effect of HIFU.
ABSTRACT
BACKGROUND:Currently rats are the most frequently used animal for the models of osteoporosis and ovariectomized rat models have been widely applied due to ovariectomized female rats are similar to human body in bone mineral density changes and response after estrogen administration. OBJECTIVE:To establish rat models of osteoporotic tooth extraction wound healing, and to investigate the effect of estrogen on the interleukin-1 expression and distribution in the remodeling of osteoporotic alveolar bone. METHODS:Sixty-five purebred female rats, 3 months old, were randomly divided into two groups:osteoporosis model group (n=40;ovariectomy under general anesthesia) and sham operation group (n=25;fat tissue around ovary was removed). After 8-week feeding, osteoporosis models were established and the left upper molar was pul ed out under general anesthesia. Histomorphomeric parameters test was performed on the jaw bone. In osteoporosis model group, 15 rats were randomly selected to give subcutaneous injection of estradiol benzoate, as the estrogen treatment group. Immunohistochemical method was applied to observe the interleukin-1 expression in the remodeling of osteoporotic alveolar bone. RESULTS AND CONCLUSION:After ovariotomy, the amount of trabecula decreased and the medul ary cavity of the bone became larger, the jaw bone intensity decreased. After administration of estrogen, the positive expression of interleukin-1 was reduced as compared with osteoporosis model group. Experimental findings indicate that, osteoporosis can be detected in Sprague-Dawley female rats aged 3 months at 8 weeks after ovariotomy, and administration of estrogen can obviously decrease interleukin-1 positive expression in the remodeling of osteoporotic alveolar bone.
ABSTRACT
BACKGROUND: The application of apparent diffusion coefficient (ADC)value to the diffusion-weighted image in the diagnosis of cerebral ischemic diseases is confirmed in clinic. The influence of different diffuse gradient direction in different lesions of human brain on diffusion-weighted image has become one of the focus researches of neuroradiology.OBJECTIVE: To explore the changing characters of the ADC value on diffusion weighted imaging with different diffuse gradient directions of human corpora striatum, parietal cortex and corona radiata.DESIGN: A sample survey.SETTING: Medical Imaging Center, the First Affiliated Hospital of Jinan University; Institute of Biomedical Engineering, School of Life Science and Technology, Jinan Univeristy.PARTICIPANTS: Sixty healthy volunteers (37 males and 23 females)aged 18-65 years were selected from the Huaqiao Hospital affiliated to Jinan University between March 2000 and March 2001.METHODS: The 60 volunteers received brain diffusion-weighted MR imaging in different directions (left-right, anterior-posterior, upper-down),and the ADC values of corpus striatum, parietal cortex and corona radiata were measured.MAIN OUTCOME MEASURES: The ADC values of corpus striatum,parietal cortex and corona radiata were measured in the 60 healthy volunteers.RESULTS: All the 60 healthy volunteers entered the analysis of results.There were no significant differences between the ADC value of corpus striatum and that of parietal cortex in different directions; the mean ADC values of corona radiata in left-right, anterior-posterior, upper-down axial were (5.0±0.5), (4.2±0.6), (15.2±1.4)×104 mrn2/s, and there were significant differences between the former two and the latter (P ＜ 0.01).CONCLUSION: Diffuse gradient directions do not affect the ADC values of corpus striatum and parietal cortex, but the ADC value of corona radiata is different. We should delineate the diffusion direction if we want to do quantitative studies on the diffusion of corona radiata.
ABSTRACT
Objective To study the roles of isotropic diffusion weighted imaging and apparent diffusion coefficients (ADC) mapping in diagnosing cerebral infarction, monitoring the development of cerebral infarction and defining the infarction stages.Methods 86 work-ups in 70 patients with cerebral infarction (8 hyperacute, 13 acute, 32 subacute, 11 steady, and 22 chronic) were imaged with both conventional MRI and single-shot echo-planar isotropic diffusion weighted imaging.The change of the infarct lesion in DWI and T_2WI was also analyzed.The average ADC, relative ADC (rADC), and the ADC from center to periphery of the lesion were calculated.Results 8 hyperacute cerebral ischemic regions were revealed at DWI and ADC mapping.Hyperacute and acute infarcts appeared as areas of hyperintensity on DWI, and their average ADC was significantly depressed compared with that of homologous contralateral tissue [(0.698?0.104) ?10 -3 mm 2/s versus (0.990?0.161)?10 -3 mm 2/s; t=-14.372, P
ABSTRACT
AIM: To study the roles of isotropic diffusion weighted imaging(DWI)and apparent diffusion coefficient(ADC)mapping in diagnosing early cerebral infarction.METHODS: 21 patients with cerebral in farction (8hyperacute,13 acute)were imaged with both conventional MRI and single-shot echo-planar isotropic diffusion weighted imaging.Among them 12 patients had CT scanning simultaneously within 24 hours after onset.The positive rate of early infarction was comparted on CT,T 2WI and DEI.The change of the infarct lesion in DWI and T 2WI was also analysed.The average ADC,relative ADC(rADC)and the ADC from center to periphery of the lesion were calculated.RESULTS: 8 hyperacute cerebral ischemic regions were revealed at DWI and ADC mapping,but CT and conventional MR were not.Hyperacute and acute infarcts appeared as areas of hyperintensity on DWI,and their average ADC was significantly depressed comparted with homologous contralateral tissue (0 698?0 104 ?s 0 990?0 161?10 -3 mm 2/s; P