Objective To sum up the imaging features of tuberous sclerosis.Methods CT and MRI findings of brain in 20 patients with tuberous sclerosis proved by clinic,imaging or pathology were retrospectively studied. Results Among 20 cases,on CT,the lesions appeared as subependymal calcified noduli in 16 cases (multiple noduli in 14 cases and single nodule in 2) and subependymal uncalcified noduli in 2,the noduli were 2~12 mm in diameter,2 cases were normal.On MRI,the subependymal noduli were multiple in 19 cases and single in one case,the noduli were iso-or hypointensity on T1WI and iso-,hypo or hyperintensity on T2WI.In addition,the lesions within cortical or sub-cortical matter were demonstrated by MRI in 19 cases,and the abnormal signals were showed in local patterns of cortical tubers.The abnormal findings of white matter were radial linear or wedge-shaped or irregular type in 7 cases.The subependymal noduli were enhanced,and the most of cortical lesions were not enhanced after contrast-enhanced MR scans in 9 cases.Conclusion There are characteristic findings of tuberous sclerosis both on CT and MRI.

Objective To study diffusion characteristic, diffusion-weighted imaging (DWI) technique and its value in lumbar osteolytic metastases. Methods Twenty patients with lumbar osteolytic metastases and 20 controls were performed with sagittal SE T_1WI, FSE T_2WI, fat saturation FSE T_2WI(FS-FSE T_2WI)and single-shot spin-echo echoplanar DWI, respectively. Contrast noise ratios (CNRs) of the metastases on various series were compared. On DWI, signal attenuation ratios (SARs) and apparent diffusion coefficients (ADCs) of lumbar osteolytic metastases and normal vertebrae were analyzed. Results (1) Routine MRI appearance: There were 23 lesions in the 20 patients. The signal intensity of all lesions showed hypointense on SE T_1WI, hyperintense on FS-FSE T_2WI and DWI, and mixed signal intensity (5 cases), isointense (12 cases) or slight hyperintense (6 cases) on FSE T_2WI. (2) CNR: The CNRs of patient group on FSE T_2WI(5.70?3.82)were lower than those on SE T_1WI(25.62?11.73), FS-FSE T_2WI(23.37?7.48)and DWI (b=600 s/mm2)(24.69?9.87)(U values were 5.393, 6.359, and 5.547, respectively,P

Objective The purpose of the study was to characterize the X-ray and CT findings of ameloblastomas of the jaw.Meth-ods X-ray (n=9)and CT (n=20)findings of 20 patients with pathologically proven ameloblastomas of the jaw were obtained.Image features included location,size,shape,density of the lesion,and changes of adjacent bone were assessed.Results 1 9 cases were located in the mandible,including 10 cases in the molar-ramus region,four cases in the whole half of the mandible body,two cases in the whole half of the mandible body and the opposide mantum,one case in the whole mandible body,two cases in the anterior teeth region and mantum.One case was located in the molar region of the maxilla.Three cases were uniocular and 17 cases were multiocular in shape.All lesions caused expansile changes in the adjacent bone,including expanding towards the lip and bucca(n=15),the lingua(n=3),and expanding uniformly(n=2).The interruptions of the surrounding bone cortex were demonstrated in 1 9 cases.Conclusion There are some characteristic imaging find-ings for ameloblastomas of the jaw.Correct preoperation dignosis can be made on the basis of imaging findings.

Objective To summary MRI findings and its diagnostic value of Balo's concentric sclerosis .Methods Brain MRI images of 4 cases with Balo's concentric sclerosis were studied with review of the literature in 13 cases.Results MRI showed multiple ring-like lesions within brains in 16 patients and single lesion only in 1.The deep white matters of cerebrum were involved in all patients.The cerebellum and brain stem were invaded in 2 and 4 respectively. Typical concentric sclerosis lesions demonstrated alternate middle and low signal rings on T1WI, middle and high on T2WI. The ring-like lesions were best seen on T1WI. The middle signal rings were enhanced on post-contrast images.The typical multiple sclerosis lesions were seen in 7 patients. Conclusion Balo's concentric sclerosis has characteristic findings on MRI.MRI is a very reliable diagnostic methed for this disease.

Objective To summarize imaging appearances of brain in AIDS patients,as to supply the evidences of imaging diagnosis for this disease . Methods CT or/and MRI appearances of brain in 19 patients with AIDS of nervous system type were reviewed . Results 3 cases showed the symmetry signal abnormal in bilateral whiter matter and 2 cases showed brain atrophy in 5 patients with HIV encephalitis.2 cases of toxoplasma encephalitis appeared multiple abnormal density or/and signal intensity in the brain and multiple ring enhancement . 3 patients with lymphoma displayed single or multiple nodule in the brain and nodular-enhancement or inhomogenous enhancement.3 patients with brain infarction displayed lower density in the basal ganglia on CT.2 patients with progressive multifocal leukoencephalopathy displaied multiple patch abnormal signal intensity of the white matter in frontal and parietal lobus.1 patient with cryptococcal infection showed abnormal signal and ring enhancement of the pons.1 patient with cryptococcal meningitis and 2 patients with intracranial hypertension had not abnormal imaging appearances.Conclusion Most lesions of the brain in AIDS patient may be detected by CT and MRI,but the definite diagnosis is still in need of combining with clinical appearances and other relative examination.

Objective To evaluate the role of magnetic resonance angiography ( MRA ) in diagnosing peripheral hemangioma andvascular malformation . Methods 61 cases of hemangioma and vascular malformations in peripheral soft tissue were undergone MRAexamination.Results Of 13 patients with hemangioma,the arteries within hemangioma were increased and gradually fine from proximal to distal in 7 cases and in company with arteriovenous fistulae in 2 cases,there were no arteries within hemangioma in 6 cases.Vascular malformations were found in 48 patients,arteries and veins of vascular malformation were showed in 35 cases,but arteries of vascular malformations were only showed in one case.Arteries of vascular malformation were showed in 5 cases and the arteries were pressed on arterial angioyraphy in 23 cases.On MR venography(MRV),the shallow malformed veina were showed in 25 cases and in company with deep malformed veina in 13 cases,only the shallow and deep veina increased and thickness be showed in 2 cases.Arterioveinous fistulae could be seen in 8 cases on MR aterio-venography.There were no vessel be showed in 12 cases within the losions.Conclusion MRA is of significant value in diagnosis and differential diagnosis of peripheral hemangioma and vascular malformations.

Objective To study the manifestations and diagnostic value of MRI for cavernous hemangioma in maxillofacial region.Methods Thirty-one cases of cavernous hemangioma in maxillofacial region proved pathologically were retrospectively analyzed.Results The lesions localized in parotideomasseteric region in 13 cases,in buccal and zygomalicotemporal region in 12 cases,in orbital area in 3 cases and labium in 3 cases.The lesions appeared as ellipse or round-like in 3 cases,fusiform in 2 cases,mass or flat irregular shape in 26 cases.On MRI,20 cases showed long T1 signal intensity,4 cases were slight long T1 and 7 cases were equal T1;on T2WI,27 cases showed high signal intensity and 4 were slight signal intensity.Conclusion The diagnosis of cavernous hemangioma in maxillofacial region can be verified and the shape,the extent of lesion can also be showed by MRI.It provides a reliable basis for clinical diagnosis and operative plan.

Objective To explore the MRI appearances of tuberculosis of myelon and spinal meninges,and to study the value of MRI in diagnosis of this disease.Methods The imaging appearances of tuberculosis of myelon and spinal meninges tuberculosis in 8 cases were reviewed.All cases underwent plain MRI and contrast-enhanced MRI examinations.Results In 8 cases,there were myelonic tuberculosis in 3,myelonic tuberculosis accompanied with spinal meninges tuberculosis in 2 and spinal meninges tuberculosis in 3.Myelonic tuberculosis appeared as intramedullary tuberculous granuloma in 2,granulitis in 1 and tuberculous myelitis in 2.The appearances of MRI were spinal cord swelling,low signal intensity on T1WI and high signal intensity on T2WI.On contrast-enhanced MRI,the lesions were circular enhancement,military nodules or non-enhancement.The typical MRI appearances of spinal meningeal tuberculosis showed spinal meninges generally thickened,narrowing or closing of subarachnoid cavity,on contrast-enhanced MRI,the lesions were tubiform enhancement of sagittal images or circular enhancement of axial images.All cases had active tuberculosis in neighbourhood organ or tissue.Conclusion The MRI appearances of tuberculosis of myelon and spinal meninges are representative,the definite diagnosis of which can be made when the MRI appearances in combination with the history of the patients and the active tuberculosis of neighbourhood organ or tissue.

Objective To study the protein expression levels of matrix metalloproteinases (MMPs)and their inhibitors in bone tissues of rat femoral head and to explore the relationship between necrosis of femoral head and glucocorticoid.Methods Twenty healthy adult SD rats were randomly divided into glucocorticoid group and control group,with 10 rats in each.Glucocorticoid group was treated with intramuscular injection of hydrocortisone twice a week.The control group received normal saline of the same volume.Four weeks later,bone tissues of left femoral head were collected from each group of rats for HE determination of femoral head necrosis.The expressions of matrix metalloproteinase-1 (MMP-1 ), matrix metalloproteinase-2 (MMP-2 ), tissue inhibitor of matrix metalloproteinase-1 (TIMP-1 ),and tissue inhibitor of matrix metalloproteinase-2 (TIMP-2 )at mRNA and protein levels were detected by RT-PCR and Western blot techniques,respectively.Results The expressions of MMP-1 and MMP-2 at mRNA and protein levels were higher in glucocorticoid group than those in the control group. However,TIMP-1 and TIMP-2 gene and protein expression levels were lower in glucocorticoid group (all P<0.05). Conclusion The expressions of MMPs in bone tissues of rat femoral head in early necrosis were increased,but their inhibitors had decreased expressions. We can draw the conclusion that glucocorticoid-induced necrosis of femoral head may be related to its regulation of the expression levels of MMPs and their related inhibitors.

Objective To sum up MRI and MR venography features of the dural sinus thrombosis (DST).Methods The findings of MRI and MR venography in 20 patients with DST were retrospectively analysed.Results MRI showed the normal flowing void of the dural sinus disappeared,instead of the abnormal high signal intensities.The easily involved positions respectively were transversal - sigmoid, superior sagittal and straight sinuses. Some cortical drainage and large internal cerebral veins were also involved . MR venography demonstrated that there were no blood flowing in these involved dural sinuses or veins . The locations of these lesions in MRI were same as that in MRV.Conclusion Because the DST can be directly displayed in MRI and MR venography,they are the most reliable methods of non- invasive diagnosis of DST.