Objective To summarize the CT manifestations of adenoid tonsic hypertrophy in children and evaluate clinical significance.Methods Twenty boys and 5 girls were diagnosed with adenoid tonsil hypertrophy,the ages from 13 to 15 years.CT scanning of nasal pharynx with 3 mm were performed in all cases.Results The thicken of adenoid tonsil hypertrophy was 13 mm to 25 mm. Sector shape of the lesion was presented in 14 cases,strip shape in 9 cases ,irregular shape in 2cases,eustachian tube stenosis or disappearance in 6 cases.The complications included:hypertrophy of tonsil in 13 cases,nasosinusitis in 11 cases,hypertrophic conchae in 21 cases,mastoiditis in 2 cases.Conclusion CT scan can accurately show adenoid tonsil hypertrophy and irregular stenotic nasopharyneal meatus and complications. CT will be the first choice in examination of adenoid tonsil hypertrophy before operation.

0.05). CTVEGB could more correctly demonstrate the surface details of polyps which were viewed in a 3D fashion in any projection than ultrasound. CTVEGB corresponded well with color Doppler ultrasound and operation and pathology in demonstrating the size, configuration and location of the lesions. Conclusion CTVEGB is a noninvasive and accurate procedure, which has a important value in clinic applications.

Objective To quantitatively study the features of cerebromspinal fluid(CSF)flow dynamies in normal sella region in MRI with phase-contrast method.Methods Seventeen healthy volunteers were studied.The CSF flow image in sella region was positioned at the middle sagittal T1WI or T2WI image.This pulse sequence used a encoding velocity of 20 cm/s.The waveforms were analyzed for the maximum flow velocity,flow volume rate and the change of the figures.From the velocity and area measurements on the cine images,mean CSF flow was calculated in millimeters per second and milliliters per cardiac cycle.Results The normal CSF flow of the sella region had two directions which was downward(caudal)flow during thesystolic period and upward(cranial)flow during the diastolic period of the cardiac cycle.The downward and upward peak flow velocity,mean downward and upward flow velocity and mean flow velocity was(1.44±0.99)cm/s,(302.71±248.15)ms,(1.16±0.64)cm/s,(331.00±225.38)ms,(0.49±0.39)cm/s.(0.67±0.44)cm/s,(0.54±O.30)cm/s,respectively.The downward and upward peak flow volume rate.mean downward and upward flow volume rate and mean flow volume rate was (0.014±0.009)ml/s.(0.012±0.006)ml/s,(0.047±0.041)ml/s,(0.053±0.003)ml/s,(0.005±0.003)ml/s,(0.034±0.031)ml/s,respectively.The mean cycle was(775.25±173.06)ms.Conclusion Phase-contrast method in MRI cine is a noninvasive method to study the CSF flow in physiological and pathological conditions for determining the pattern,direction,speed and quantity of the CSF flow.Therefore it is better than other invasive research modalities and has an important value in clinical application.

Objective To explore the diagnostic value of MRI in invasively pernicious placenta previa.Methods MRI and color doppler ultrasound were performed in 1 50 patients with pernicious placenta previa.According to the operation or pathology findings, the diagnostic value of placental invasion was compared among MRI,color doppler ultrasound and both of them.Analyzed and com-pared the MRI findings of 64 patients which were confirmed as invasive placenta including adherent placenta in 20 patients,implanted one in 38 and penetrated one in 6.Results Significant difference was not found among MRI,color doppler ultrasound and both in the diagnostic value of invasive placenta (P >0.05).There was a significant difference among adherent placenta,implanted one and pen-etrated one in the diagnostic value of MRI (P <0.05),and the highest and lowest values were penetrated placenta and adherent pla-centa respectively.Conclusion MRI is an important diagnostic method in invasively pernicious placenta previa,which was useful for its classification but with a limitation for the diagnosis of adherent placenta.

Objective To assess the accuracy of SIEMENS Osteo software.Methods The mineral content of 20 cadaver lumber bodies(L 1～L 5) was measured by quantitative CT,and compared with bone ash analysis.Results Mineral content and bone ash weight had a linear correlation,which could be expressed by followed regress equation:ash weight=0.92432?BMD+39.0633.The results with quantitative CT method were all lower than that with bone ash analysis (average lower 29.196 mg/cm 3).Conclusion There are some deviations for measuring bone mineral content with this software.The deviation is within the limit of the theory error of single energy quantitative CT.The result of the measurement shoud be accurate after proofread.

Objective To research the brain hemodynamic changes in hyperacute cerebral infarction. Methods Focal cerebral ischemia models were presented in 42 healthy New Zealand rabbits by obstructing the unilateral middle cerebral artery with modified O’Brein method. Dynamic scans with intravenous bolus injection of contrast were performed at 0.5, 1, 2, 3, 4, 6h separately after operation by Siemens Somatom Plus 4 Power spiral CT scanner. Then data were input into Siemens Magic View 50 workstation and processed with perfusion CT/VA 10B system. Six cerebral blood functional perfusion maps were obtained. rCBF, rCBV, rTP, rTS of bilateral symmetric interesting regions were calculated. Results Between 0.5-6 hours after operation, the rCBF and rCBV of ischemic cores and peri-ischemic areas decreased subsequently along with times of ischemia developing. rTP、rTS of cores increased at first, then decreased to 0. rTP, rTS of peri-ischemic areas prolonged at all times. Conclusion The ischemic degree, perfusion state of ischemic tissues in brain can be estimated by hemodynamic parameters, which provide useful information for the diagnosis, therapy and prognosis of hyperacute cerebral infarction.

Objective To investigate the differences of low frequency fluctuation (ALFF)in the resting state between short-term heroin and methamphetamine abusers after withdrawal.Methods Sixteen male short-term heroin abusers and fourteen male short-term methamphetamine abusers were performed the functional magnetic resonance imaging (fMRI).The differences of ALFF be-tween the two groups were performed with preprocessing softwares.Threshold was set to 0.05.Results Compared with metham-phetamine-dependent patients,heroin-dependent patients showed increased ALFF in the left side of the lingual gyrus and the left ton-sil of cerebellum and decreased ALFF in the left side of the brain stem,midbrain and the left side of the cerebellar vermis.Conclusion There are differences between the short-term heroin and methamphetamine abusers in the function of the brain,mainly involving the brain regions associating with cognition and affection.

Objective To explore the value of MR diffusion tensor imaging ( DTI) in diagnosis of traumatic Axonal injury ( TAI) .Methods Twenty nine patients with traumatic brain injury ( TBI) and matched 22 control subjects were performed with DTI . Fractional anisotropy ( FA) was calculated from semioval center , corpus callosum , internal capsule and pons of controls and TBI pa-tients.According to Glasgow Score (GCS), TBI patients were divided into mild group (GCS≥13) and moderate-severe group (GCS≤12), each group compared with control group in FA value .The correlation between FA values in different regions and GCS score were analyzed in DTI group .Results FA value of semioval center was decreased in mild DTI group ( P <0.01 ) .FA values of semio-val center , corpus callosum , and internal capsule were decreased in moderate-severe DTI group ( P <0.05 ) .The FA values in semio-val center , corpus callosum , and internal capsule were positively correlated with GCS score in TBI group ( P <0.05 ) .Conclusions DTI is sensitive to detect the traumatic axonal injury??Changes of FA value in ROIs can access the severity of axonal injury ?? which ishelpful for diagnosis earlier and improving prognosis.

Objective To analyze the correlation between MRI features and pathological characterization of ovarian thecoma-fibro-ma.Methods MRI manifestations of 21 patients with ovarian thecoma-fibroma proved by pathological diagnosis were analyzed retro-spectively and compared with pathologic findings.Results The 21 cases involved 22 lesions (one patient had bilateral masses of the-cofibroma),including 13 fibrothecoma,4 thecofibroma and 5 fibroma.All lesions presented with well-defined margin,and cystic changes were found in 1 5 cases,7 lesions were solid masses ,1 9 lesions were round or oval masses ,2 lesions were lobulated mas-ses,and 1 lesion was irregular mass.The diameters of tumor ranged from 3.4 to 18.5 cm with mean diameter of 8.9 cm.On MR images,all lesions showed isointense or slight hypointense on T1 WI.On T2 WI,most tumors showed isointense or slight hypoin-tense,along with hyperintense cystic areas in 1 5 lesions,patchy slight hyperintense edema areas in 4 lesions,and homogeneous isointense or slight hypointense in 3 lesions.After contrast enhancement,all lesions demonstrated mild-to-moderate enhancement and delayed progressive enhancement slightly.13 cases associated with varied degrees of pelvic effusion,1 case with thickening of endometrium,and 1 case with endometrial carcinoma.Two patients had a higher level of CA125.Postoperative pathology demon-strated that all lesion were benign.Conclusion The MRI findings of the ovarian thecoma-fibroma are considerably characteristic and indirectly reflect pathology of tumor,thus beneficial to the correct diagnosis of tumor with relevant clinical information.

Objective To investigate temperature changes in prefrontal cortex and hippocampus of heroin addicts with magnetic resonance spectroscopy (MRS).Methods 18 heroin addicts in the withdrawal state and 18 healthy volunteers (control group) were performed with MRS scan.First, resting-state MRS scan was performed on all subjects, and then did MRS scan again under visual stimulation while subjects were asked to carefully watch the heroin-related cue images.Measurements of NAA of the identified regions (the prefrontal cortex, bilateral hippocampus) were obtained from all subjects.Brain temperatures were calculated by the modified brain temperature-chemical shift equation.Results In resting state, the temperature of prefrontal cortex in heroin addicts group was higher than the control group, the difference was statistically significant (P<0.05),and the brain temperature was positively correlated with total dose of heroin (P<0.05).The prefrontal cortex/hippocampus temperature of heroin addicts group did not showed statistical significance between resting state and visual stimulation state (P>0.05).Conclusion MRS can be used to measure brain temperature noninvasively.Temperature change of brain may be helpful for exploring the mechanism of drug addiction and craving.