(4.2)--中枢医学影像诊断学.ppt

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1、Brain tumorPituitary Adenomas acount for 10%of all primary intracranial tumors macroadenomas and microadenomasmicroadenomas 10 mm or less in diameter plain CT isodense with the adjacent normal pituitary gland Enhancement occurs is usually delayed compared to the immediate,intense enhancement of the

2、normal pituitary gland macroadenomas are larger that 10 mm Necrosis,hemorrhage,and cyst formation are common isodense with cortex on plain CT scans have a characteristic figure“8”appearance on imagingMRI plainMacroadenomas can bulge superiorly extending through the diaphragma sellae into suprasellar

3、 cistern.Optic chiasma is compressedMRI contrast have a characteristic figure“8”appearance on imaging Contrast MRacoustic neuroma is the most common cerebellopontine angle(CPA)mass accounting for 75%to 80%of all lesions in this location Imaging Location CPA slightly hypointense/isointense to brain o

4、n T1WI the internal acoustic canal become wider Calcification and hemorrhage are rare.Intense enhancement Metastatic Tumors account for 30%of intracerebral tumors At gray-white interface Multiple Edema is striking enhance strongly Metastatic TumorsBrain trauma Have a trauma history Skull fracture Di

5、ffuse Cerebral Edema Epidural Hematoma(EDH)Subdural hematoma(SDH)Brain traumaEpidural Hematoma(EDH)Definitions Blood collection within potential space between skull inner table&duramaterEpidural Hematoma(EDH)Features in images Hyperdense biconvex mass on CT in acute phase Location:Epidural space bet

6、ween skull&dura,nearly all EDH occur at impact site Does not cross sutures,but can cross falx&tentorium Compresses&displaces underlying brainScalp Hematomas Epidural HematomaSubdural hematoma(SDH)Definitions hemorrhagic collection in subdural spaceSubdural hematoma(SDH)Crescent-shaped,homogenously h

7、yperdense on CT,extra-axial collection that spreads diffusely over affected hemisphere Location o Between arachnoid&inner layer of dura o May cross sutures o May extend along falx&tentorium o Compresses&displaces underlying brainSubdural HematomaSubdural HematomaNontraumatic Hemorrhage Etiology:Hype

8、rtension,Aneurysm,Vascular Malformation,stroke Location:basal ganglia thalamus pons Features on images:Hyperdense(50-70 HU)mass on NECTCerebral infarction Infarction refers to brain damage,being the result of ischemia 6h plain CT scans negative MR positiveLacunar lnfarctsArteriovenous malformation(A

9、VM)Imaging features Best diagnostic clue:Bag of black worms(flow voids signal)on MR with minimal/no mass effectCONTRASTANEURYSMImaging features Round/lobulated outpouching Location:circle of Willis or Middle cerebral artery(MCA)bifurcation Technique:DSA,CTA,MRA 3D-VR3d3D-VR动脉瘤ANEURYSMDiscussionCase1

10、 Femal patient,25 years old Amenorrhea and lactation for 1 yearCase 2Male patient,30 years oldHis head was hit at a traffic accident 4 hours ago Case 3Male patient,40 years oldHis head was hit at a traffic accident 5 hours agoCase 4 Female patient,50 years old Audition lost on right ear for 3 monthCase 5 Female,57 years Tinnitus for 2 months