急性及亚急性脊髓髓内病变MRI诊断与鉴别诊断思路》专题讲.ppt

急性及亚急性脊髓髓内病变MRI诊 断与鉴别诊断思路 脊髓病变脊髓病变 良性病变良性病变 n脊髓空洞症 nVentriculus terminalis n挫伤 n脓肿 n梗塞 n脊髓炎 n多发性硬化 n郝-伯二氏病（肉样瘤 病） n动静脉的畸形 占位性病变占位性病变 n畸胎瘤 n星形细胞瘤 n室管膜瘤 n成血管细胞瘤 n淋巴瘤 n成神经节细胞瘤 n转移 The typical MR imaging protocol for evaluation of the spinal cord lesions nunenhanced sagittal and axial T1-weighted and T2 -weighted images npost-gadolinium-enhanced sagittal and axial T1- weighted images. nideally with MRI of the entire spine. Contrast-enhanced images are helpful in determining the solid portion of an intramedullary neoplasm, tumoral vs nontumoral cysts, other enhancing pathologic entities, or other features that may modify the differential diagnosis. WHEN IT IS AN ACUTE MYELOPATHY ， WHAT CAUSES SHOULD BE CONSIDERED? nIn patients with recent onset symptoms, particularly ones that evolve rapidly, the initial priority is to exclude a surgical emergency such as epidural metastasis or abscess. nimmediate imaging is required, ideally with MRI of the entire spine. nIf imaging demonstrates spinal cord compression due to an acute lesion such as epidural metastasis, definitive management (i.e., surgery) should be pursued without delay to prevent rapid and irreversible worsening. 一、与肿瘤有关一、与肿瘤有关 Sagittal T1-weighted MR image (a) of the thoracic spine illustrates diffuse marrow hypointensity Gadolinium-enhanced T1-weighted MR image (b) depicts multiple heterogeneously enhancing lesions (yellow arrows). The STIR MR image (c) shows abnormally increased signal in the posterior elements and the vertebral bodies. A compression fracture is seen in the upper thoracic spine (red arrow). Epidural lymphoma. A 62-year-old man with known history of lymphoma presents with progressive back pain and lower extremity weakness and paresthesias. Sagittal and axial T2 (A, C) and postcontrast T1 (B, D) images demonstrate an elongated enhancing epidural mass(long arrow) at the posterior aspect of the spinal canal with extension into the neural foramina, causing compression and displacement of the thecalsac and spinal cord anteriorly. A hypointense dura (arrowhead) is displaced anteriorly. The mass is in the same posterior epidural space as the epidural fat (short arrow). nIntradural-extramedullary schwannoma. nA 55-year-old patient with right lower extremity weakness. Sagittal and axial T2 (A, D) and pre-(B, E) and postcontrast T1 (C, F) images demonstrate a relatively homogeneously enhancing lesion of isointense T1 and hyperintense T2 signal within lower thoracic spine causing displacement and compression of the spinal cord. Identification of the dura (arrows), which has low signal on all sequences, confirms the intradural location of the lesion. The contour and eccentric location of the lesion with mass effect on the spinal cord also confirm its extramedullary origin. Epidural spinal cord compression nMRI T2 (A) and postcontrast T1 (B) of a 61- yearold male with hormone-refractory prostate cancer who presented with 1 month of neck and mid back pain. nHe was treated with 3000 cGy in 10 fractions to C1C5 and T1T6 with improvement in his symptoms. nNeuroimaging demonstrated epidural disease at C2 and C3 and T4 and T5 with cord compression. Neurologic exam was normal except for mild hyperreflexia in the lower extremities. Epidural spinal cord compression Leptomeningeal metastases This 34 year old had a 3-year history of melanoma黑素瘤and an 18-month history of brain metastases. She then presented with sciatic-type leg pain followed by constipation and patchy sensory loss from her chest to her thighs. She manifested a markedly positive straight leg raise, mild leg weakness, and diminished deep tendon reflexes in her legs. The postgadolinium MR scan demonstrates numerous small leptomeningeal enhancing nodules. 二、与感染或免疫有关二、与感染或免疫有关 Tuberculous spondylitis. 结核性的脊椎炎 Tuberculous spondylitis of Th 4 and epidural abscess with right laterovertebral spread. a Sagittal T2, b T1,and c T2 spectroscopic inversion recovery (SPIR) showing tuberculous spondylitis. d Axial Gd T1- weighted image demonstrates best the extradural abscess as well as the perivertebral extension nTuberculous spondylitis: role of SPIR pulse sequence. nSagittal T2 SPIR image of the lumbo- sacral region shows the tuberculous involvement of L5 with extension to the L4L5 intervertebral disc Spondylitis and spondylodiscitis Pyogenic spondylitis is uncommon and represents only 24% of pyogenic osteomyelitis骨髓炎. Mainly adults in the sixth to seventh decades are affected. The rule of 50% should be remembered: 50% of the patients are older than 50 years, fever is present in only 50% of the cases; genitourinary tract is the primary source of infection in 50% of cases, Staphylococcus aureus is the causative agent in almost 50%; the lumbar spine is affected in 50%; patients present with a history of more than 3 months of symptoms in 50% of cases nC6C7 cervical spondylitis and spondylodiscitis. Associated large epidural abscess. na Sagittal T1-weighted image, b sagittal T2- weighted image, and c sagittal fat-suppression T2 images. The vertebral bodies of C6 and C7 are hypointense on T1-weighted image, hyperintense on T2 and fat-suppressed T2-weighted image.Partial collapse of C6. The epidural abscess is best seen on T2-weighted image as a hyperintense fluid collection. d Sagittal Gdenhanced T1-weighted image better shows the epidural abscess due to enhancement of the dura. e Axial T2-weighted image shows well the epidural left postero-lateral pus collection 三、与正常结构有关三、与正常结构有关 椎间盘突出椎间盘突出 黄韧带肥厚黄韧带肥厚 脂(肪)过多症 Spinal epidural lipomatosis nSpinal epidural lipomatosis (SEL) is a rare but well- recognized condition. nIt is defined as a pathological overgrowth of normal fat tissue in the extradural space. nSteroid production (exogenous or endogenous) is the main aetiological factor associated with SEL; the first case of steroid-induced lipomatosis was reported by Lee et al.（ 1975） Other reported secondary causes include adrenal tumors, hypothyroidism,hyperprolactinemia and other endocrinopathies. nMany cases have emerged without evidence of any clear predisposing factors. Badami et al. reported the first case in 1982 but Haddad in 1991 coined the term idiopathic SEL. TI-weighted axial MRI showing epidural lipomatosis compressing the spinal cord. T1-weighted sagittal MRI showing the epidural lipomatosis compressing the upper thoracic spinal cord. n n 四、与运动、外伤等等有关四、与运动、外伤等等有关 Sagittal T2- (A) and T1-weighted (B) magnetic resonance images of an acute epidural hematoma with maximal compression at the C6-C7 level (arrows) in a 13-year-old girl who sustained a heavy rowing exercise injury with an underlying vascular malformation. MRI Findings in Spinal Epidural Hematoma Phase T1-weighted T2-weighted Image Acute Isointense Hyperintense Subacute Heterogeneous Heterogeneous Chronic Hypointense Hypointense Sagittal T2-weighted cervical magnetic resonance image shows a longitudinal posterior epidural hematoma from C4 to C5(arrow), compressing the spinal cord (arrowhead) Axial T2-weighted cervical magnetic resonance image shows an ovoid epidural hematoma (arrow) in the right postero-lateral aspect and spinal cord compression (arrowhead) Sagittal T1 and T2 turbo-spin-echo Sagittal T1 and T2 turbo-spin-echo sequences of the posterior spinal canal.sequences of the posterior spinal canal. n n A A, Sagittal T1 revealing mixed signal , Sagittal T1 revealing mixed signal intensity in the posterior spinal canal intensity in the posterior spinal canal mostmost marked from approximately the T1 marked from approximately the T1 level to the T7 level, with minimal level to the T7 level, with minimal findings extending into the lower findings extending into the lower thoracic and upper lumbar levels. thoracic and upper lumbar levels. There is an area of high signal There is an area of high signal intensity extending from the T3 to the intensity extending from the T3 to the T5 level (T5 level (arrowsarrows). ). n n B B, Sagittal T2 revealing mixed signal , Sagittal T2 revealing mixed signal intensity in the posterior spinal canal intensity in the posterior spinal canal most marked from approximately the most marked from approximately the T1 level to the T7 level, with minimal T1 level to the T7 level, with minimal findings extending into the lower findings extending into the lower thoracic and upper lumbar levels.