0.05).The values and ages were positive correlation before age 25(r=0.71～0.91,?0.05).Four main patterns of marrow distribution were identified in the proximal femur.Our data implied that there was progressive marrow fat distribution with age.The diaphyseal red marrow began to convert to yellow marrow after 5 years old and the conversion completed at age of 10.Foci of longer T 1 signals were found in the diaphysis in some of the subjects and the percentage increased with age.The femoral head and the greater trochanter showed yellow marrow signals after ossification.Conclusion Measurement of MRI signal intensity values could be used in evaluating the conversion of red to yellow marrow of the femur.Red and yellow marrow of femur may be distinguished by MRI.We should notice the different MRI feafure in different ages.

Objective To evaluate the CT and MRI features of masticator space lesions.Methods All patients(43 cases) were examined with CT (28 cases) or MRI(10 cases),and 4 cases underwent both CT and MR examination.Results 9 cases of masticator space infection were found,which had characteristic appearances and patterns of widely spread on CT and MRI,and CT was better in detecting mandibular osteomyelitis.Primary tumors of the space included 6 cases of rhabdomyosarcomas,5 cases of angioma,4 cases of osteosarcomas.Most of them had the particular CT or MRI features.In 19 cases of metastasis of the space,most came from surrounding structures,especially from squamous cell carcinoma of the head and neck,and penetrating deeply into the muscles or ramus of masticator space.Conclusion The masticator space lesions(infection and most of tumors) are of characteristic features on CT and MRI.

Objective To observe and measure the facial nerve canal(FNC) in curved planar reformation by multislice spiral CT.Methods High resolution computed tomography (HRCT)of temporal bone was performed in 40 cases (80 ears) by multislice spiral CT. Curved planar reformation of FNC was performed separately in axial, coronal and sagittal plane of multiplanar reconstruction. The morphology and measurement of FNC were studied.Results The mean length of FNC was (29.73?1.07)mm. The mean length of the labyrinthine, tympanic and mastoid segment was (5.6?0.74)mm, (10.66?0.79)mm and (13.47?1.01)mm respectively. The mean diameter of the l-abyrinthine, geniculate fossa, tympanic and mastoid segment was (0.76?0.16)mm, (2.37?0.63)mm, (1.03?0.16)mm and (1.57?0.31)mm respectively. The mean angle of first and second genu was 67.04??9.41? and 114.25??8.44? respectively. The distance between the tympanic segment and ampulla of the lateral semicircular canal was (0.57?0.19)mm. The distance between the tympanic segment and arch of the lateral semicircular canal was (1.59?0.61)mm. The mean angle between the tympanic segment of the facial nerve canal and the lateral semicircular canal was 10.63??3.60?. The tympanic course of the facial nerve canal formed an angle of 34.65??5.39? with the sagittal plane. Dehiscences was found in 89% FNC, 73.7% of them only located in the tympanic portion and 26.3% both in the mastoid and tympanic portions. Conclusion Curved planar reformation of FNC by multislice spiral CT is the good method to study the anatomy of FNC,and in combination with HRCT axial scan and multiplanar reconstrution can obtain more valuable information.

Objective To explore the high-resolution CT manifestation of chronic otitis media with cholesteatoma. Methods clinical and high-resolution CT manifestation of 31 cases of chronic otitis media with cholesteatoma were analyzed. All the cases were confirmed by operation and pathology. Results High-resolution CT can accurately show the signs of soft-tissue occupancy and bony-erosion of cholestcatoma in middle ear which originate from various sites and of various sizes.confirmed by operation, accuracy were as high as 93.5%-100% . Conclusion high-resolution CT is extremely accurate in diagnosis of chronic otitis media with cholesteatoma.

Objective To study the findings of CT and MRI in tongue cancer.Methods 21 cases of tongue cancer were examined by CT or MRI,CT examined 7 cases,MRI examined 14 cases.Results MRI could display the tongue cancer in all the cases,but CT only display 5 of 7 cases of the tumour.The value of CT and MRI was same in displaying soft tissue direct invasion.MRI and contrast enhanced CT could display cervical lymph node metastases.CT was superior to MRI in the diagnosis of mandible invasion.Conclusion MRI is superior to CT in the display soft tissue of tongue cancer and the metastases.CT is optimal in detection of cortical bone invasion.

Objective To investigate the diagnostic value comparatively of CT and radiography in pneumoconiosis.Methods Chest radiographic and CT images were analyzed retrospectively in 52 cases with pneumoconiosis.Results The pulmonary disseminated small shadowes (diameter 10 mm),13 cases and 9 cases were detected by CT and radiography respectively.20 cases (5 pneumonia,3 pulmonary tuberculosis,1 lung cancer,6 pneumothorax,4 pulmonary emphysema) and 10 cases (1 pneumonia,1 pulmonary tuberculosis,6 pneumothorax,2 pulmonary emphysema) with complications were showed by CT and radiography respectively.Conclusion CT is not superior to radiography in diagnosis of simple pneumoconiosis,but CT is superior to radiography detecting the big shadow of lung and complications,and it can help radiologists to avoid mistakes.

Objective To study the facial nerve canal (FNC) abnormalities of the congenital external auditory canal (EAC) atresia by MSCT curved planar reformation (CPR).Methods 15 cases(17 ears) of congenital EAC atresia were scanned by MSCT. Post-processing images were completed by Philips Mx8000 workstation.Results In 17 ears, there were 2 ears with stenosis of EAC, 2 ears with membranous atresia of EAC and 13 ears with bony atresia of EAC.There were 1 ear with congenital cholesteatoma, 3 ears with malformation of tympanum, 7 ears with malformation of the ossicular chain and 1ear with malformation of inner ear. In 17 ears with abnormalities of FNC, included 11 ears with the shortness of FNC general length, 5 ears with the anomalous course of FNC, 9 ears with the displacement of FNC, 1 ear with the narrowing of FNC and 1 ear with the branch of FNC.Conclusion MSCT CPR of FNC, combined with HRCT axial scan, can clearly show the FNC abnormalities of the congenital EAC atresia and provide valuable information for surgery.

Objective Adverse reactions to Gd-DTPA contrast media should be noticed enough.Methods Three cases of adverse reactions to Gd-DTPA contrast media were studied, and literatures were reviewed.Results The rate of adverse reactions to Gd-DTPA contrast media in our hospital was 0.206%.Conclusion Although the rate of adverse reactions to Gd-DTPA contrast media is very low, this problem must be noticed enough with the medical quality’s developement.

Objective Using curved planar reformation(CPR)to delineate the ossicular chain(OC)in one image and evaluate its clinical application. Methods HRCT of temporal bone was performed in 122 cases(165 ears).The CPR of OC was then performed.The main parameters were as follow:collimation 0.5mm,pitch 0.875,reformation interval 0.2～0.3mm,reformation matrix 1024?1024.Results (1)CPR of normal OC were performed on 80 ears,the three ossicles and its joints could be showed on one image clearly.(2)Clincal application(72cases):in 39 cases of temporal bone trauma,OCs were normal in 21 cases and abnormal in 18 cases.Subluxation or dislocation of malleoincudal joint(MIJ)(5,5) and incudostapedial joint(ISJ)(5,6),dislocation of MIJ and ISJ with rotation of incus(1 case),fracture of manubrium of malleus(1 case) were found respectively.In 16 cases of external auditory canal dysplasia(EACD),the most commonly associated type of OC deformity was absence of manubrium of malleus(10 cases)。Absence of OC associated with coarctation of middle ear cavity(3 cases) and fusion of the malleus and incus associated with absence of long process of incus represented in 1 case.Congenital ossicular anomalies without associated EACD were found in 2 cases.The long processes of the incus of both side were absent in 1 case.Incudostapedial disconnection was demonstrated in 1 case due to improper development of the long process of the incus.In 15 cases of chronic otitis media(COM),6 cases were complicated cholesteatoma.Destruction of OC was demonstrated in 6 cases.Conclusion CPR of OC with multislice spiral CT is an effective method in the diagnosis of conductive hearing loss.

Objective To study the methods of delineating the whole length of bilateral facial nerve canals in one image. Methods High resolution computed tomography of the temporal bone was performed in 60 cases (120 ears) by Philips Mx8000 multislice spiral CT. Parameters: 120 kV, 200～250 mAs, Collimation: 0.5 mm, Pitch: 0.875, Scan time: 0.75 s/ring, Matrix: 512?512, Reformation interval: 0 1～0.2 mm, Reformation matrix: 1 024?1 024. Curved planar reformation(CPR)images were prepared along the facial nerve canal in the axial plane, and in the coronal and sagittal plane of multiplanar reconstruction(MPR). In the axial plane, a reference line was traced following the facial nerve canal from the internal auditory meatus, through the labyrinthine segment, the tympanic segment up to the second genu and mastoid segment. Another two protocols of curved reformatting were adopted: (a) a curved line was delineated along the facial nerve canal on the coronal reformatted image; (b) a curved line was drawn along the facial nerve canal on the sagittal reformatted image. The reference lines were carefully revised and moved exactly to the center of each segment of the facial nerve canal. For displaying bilateral facial nerve canals in one image, one reference line should be drawn along bilateral facial nerve canals. Results In 56 cases of 60 CPR, images in the axial plane, and coronal plane of MPR could show the unilateral or bilateral facial nerve canals clearly. The result of CPR of bilateral facial nerve canals in sagittal plane of MPR was unsatisfactory. The image on one side was often clear, but just part of it could be showed on the other. So the left and right facial nerve canals should be reformed separately. In 4 cases, CPR was unsatisfactory. In 1 of them the labyrinthine and tympanic segment had breaks because the patient′s head shook during the scanning. In 3 of them the facial nerve canals were showed unsatisfactorily because of the inexact position of head during the scanning. Conclusion The unilateral or bilateral facial nerve canals could be showed in one image by CPR. Combining the images of the high resolution CT in axial scan and MPR of the temporal bone, it would be helpful in the diagnosis of the lesions of facial nerve canal.