幕上肿瘤鉴别诊断课件.ppt

1、IMAGING OF SUPRATENTORIAL NEOPLASMS,CHI S. ZEE, M.D PROFESSOR OF RADIOLOGY AND NEUROSURGERY DIRECTOR OF NEURORADIOLOGY,TUMOR IMAGING PROTOCAL,Sag T1 WI Axial T1 WI Axial T2 WI Axial FLAIR Post-contrast T1 WI in three planes Diffusion weighted imaging and diffusion tensor imaging MR proton spectrosco

2、py Perfusion imaging if needed,MR Proton Spectroscopy,Choline is the key metabolite in brain tumor (a constituent of the phospholipid composition of cell membranes) Inverse correlation of cho level with ADC value NAA level correlates with neuronal tissue Lactate is believed to be due to glycolytic a

3、ctivity Lipids are associated with cellular breakdown and necrosis,CHEMICAL SHIFT IMAGING,Hamartoma,Recurrent Tumor vs Radiation changes,Recurrent Tumor vs Radiation changes,Perfusion Imaging,Regional CBV is calculated from signal intensity loss engendered by the passage of contrast Perfusion imagin

4、g probably reflects tumor angiogenesis Regional CBV correlates with tumor vascularity and mitotic activity,PERFUSION IMAGING,Diffusion Tensor Imaging,Presurgical planning with diffusion tensor imaging using tractography Involvement of white matter tracts by infiltrating tumor Anatomically intact whi

5、te matter tracts may be present in abnormal appearing areas,Color FA Map (Tumor Patient),3D Tractography (Tumor patient)Example of all tracts that intersect a selected slice (slice 14 /28),INTRA-AXIAL NEOPLASMS,Glioblatoma multiforme胶母 (WHO gade VI) Anaplastic Astrocytoma (WHO grade III) Infiltratin

6、g Astrocytoma (WHO grade II) Well-defined Astrocytoma星行细胞瘤 (WHO grade I) Oligodendroglioma少突胶织细胞瘤 Ependymoma室管膜瘤 Ganglioglioma神经节细胞瘤 Dysembryoplastic neuroepithelial tumor PNET胚胎发育不良性神经上皮肿瘤 Lymphoma淋巴瘤 Metastasis转移瘤,CEREBRAL GLIOMAS,GBM (55%) Astrocytoma (20%) Ependymoma (6%) Oligodendroglioma (5%)

7、Choroid plexus papilloma (3%),ASTROCYTOMAS (WHO grade 1),Pilocytic astrocytoma Pleomorphic xanthoastrocytoma Giant cell astrocytoma,Hypothalamic/ optic Glioma视交叉胶质瘤,Giant Cell Astrocytoma巨细胞星形细胞瘤,SUBEPENDYMAL GIANT CELL ASTROCYTOMA,Occurs almost exclusively in patients with tuberous sclerosis in the

8、ir late teens and early twenties 10 to 15 % of patients with tuberous sclerosis develop SGCA Arise from subependymal nodules located wall of the lateral ventricle overlying the head of caudate nucleus,FLAIR,POST-CONTRAST,Infiltrating Glioma侵润性胶质瘤,SPECTROSCOPY,LOW GRADE ASTROCYTOMA,Hypercellular tumo

9、rs with few mitoses and moderate pleomorphism No vascular proliferation or necrosis Strong affinity for glial fibrillary acidic protein (GFAP) Arise in the white matter and grow by infiltration along the white matter tract,Anaplastic Astrocytoma,ANAPLASTIC ASTROCYTOMA,High cellularity, frequent mito

10、ses, and foci of vascular proliferation Usually no necrosis is present A progressive dedifferentiation of a previously low grade astrocytoma,GLIOBLASTOMA MULTIFORME,GLIOBLASTOMA MULTIFORME,The most common primary tumor of the CNS Characteristically involves the white matter, but infiltrates and dest

11、roys gray matter with loss of G-W differentiation Areas of hypercellularity, cellular pleomorphism, endothelial proliferation, and intratumoral necrosis Peritumoral edema is always present,Ependymoma,T1WI,FLAIR,POST-CONTRAST,Ependymoma,Approximately 30% occur supratentorially Supratentorial ependymo

12、mas occur mainly in second through the fourth decades Slow growing tumors of moderate malignancy Tendency to reccur and seed via the subarachnoid space Highly cellular tumors with perivascular pseudorosette formation,TANYCYTIC EPENDYMOMA,An uncommon fibrillar variant of ependymoma in new WHO classif

13、ication True ependymal rosettes are absent and perivascular rosettes are inconspicuous Misdiagnosis as schwannoma or astrocytoma is a common problem Ultrastructural examination shows characteristic ependymal features,Oligodendroglioma,DIFFUSION IMAGING,Oligodendroglioma,Oligodendrogliomas comprise 2

14、% to 5% of all primary intracranial tumors and 5% to 10% of all gliomas. Pure oligodendrogliomas are uncommon. Oligodendrogliomas are tumors of adults. The ratio of adults to children is 8:1. The peak incidence is between 35 and 45 years of age. They are predominantly seen in frontal and frontotempo

15、ral region. Seizures are the most common presenting symptom.,Ganglioglioma,DIFFUSION IMAGING,Ganglioglioma,Slow growing tumor that contains both neuronal and glial elements. Children and young adults, with a female predominance. Less than 1% of all primary brain neoplasms. Predominantly in temporal

16、lobes, less frequently in posterior fossa, thalamus, pineal gland. Usually solitary. Assoicated with seizures of long duration.,GFAP,Chordoid gliomaAJNR 22: 464-469, 2001,A new clinicopathologic entity in the hypothalamic region recently added to WHO tumor classification It is named chordoid glioma

17、because of its distinctive histologic appearance, reminiscent of chordoma, and its avid staining with GFAP Ovoid, well circumscribed mass with uniform and intense enhancement. Isointense on T1 WI and slightly hyperintense on T2 WI.,PNET,Cerebral Neuroblastoma,Supratentorial PNET are rare 5% of all s

18、upratentorial tumor in children Large heterogeneous mass with necrosis, cyst formation, hemorrhage and calcification The solid component is isointense to gray matter on T1 WI and slightly hyperintense on T2 WI,DNET,Dysembryoplastic Neuroepithelial Tumor Very uncommon Extremely slow growing Found in

19、first few decades Present with long-standing seizure Surgery is typically curative,DNET,Cortical mass, always supratentorial Usually in temporal lobe Skull remodelling due to slow growth,Lymphoma,Lymphoma淋巴瘤,Most primary CNS lymphomas are high grade non-Hodgkins B-cell lymphomas Lesions can be multi

20、ple and involving basal ganglia, periventricular white matter, and corpus callosum Imaging appearance are quite different in immuno-competent and immuno-compromised patients,POST-CONTRAST,MR Proton Spectroscopy,Burkitts Lymphoma,Burkitts lymphoma is a solid tumor of B lymphocytes. It is one of the f

21、orms of Non-Hodgkins lymphoma.The tumor was first described in 1958 by Denis Burkitt, a surgeon working in Africa. In almost all cases of African Burkitts lymphoma the cells carry the Epstein-barr virus.,INTRAVENTRICULAR NEOPLASMS,Central Neurocytoma Ependymoma Choroid plexus papilloma Meningioma,Ce

22、ntral Neurocytoma,T1 WI,T2 WI,FLAIR,POST-CONTRAST,MR Proton Spectroscopy,Central Neurocytoma,T2 WI,Central Neurocytoma,Central Neurocytoma is a relatively benign intraventricular neoplasm that is distinct from ganglion cell tumors,neuroblastomas, and PNET. On gross pathology, central neurocytomas ar

23、e well circumscribed and attached to the septum or the lateral ventricular wall. On microscopy, the tumor is reminiscent of oligodendroglioma Neuronal origin is determined by electron microscopy and immunohistological stain is positive for synaptophysin Tumor of young adults,Choroid plexus papilloma

24、,T1 WI,T1 WI,T2 WI,POST-CONTRAST,Choroid plexus papilloma,Less than 1% of all brain tumors 40% of all brain tumors in the first 60 days of life Lateral ventricle tumors tend to occur in children; 4th ventricle tumors occur in adults Consists of well differentiated proliferation of both the surface e

25、pithelium of the choroid plexus and the underlying vascular connective tissue,POST CONTRAST,Intraventricular Meningioma,Most common tumor of atrium over age 30 0.5 2% of all meningiomas are intraventricular. Female predominance of 2:1 CT is better in showing calcification Arises from stroma of CP or from rests of arachnoid tissue within choroid.,EXTRA-AXIAL NEOPLASMS,Meningioma Lymphoma Metastasis Hemangiopericytoma,POST-CONTRAST,Meningioma,The most common nongl