磁共振成像
MRI使用强大的磁体和无线电波产生器官和软组织的详细图像。非常适合大脑、脊柱和关节成像。
什么是 MRI？
MRI（磁共振成像）是一种无创成像技术，使用强大的磁场和无线电波创建器官和组织的详细图像。与CT扫描不同，MRI不使用电离辐射，使其更适合重复成像。
工作原理： 您的身体被放置在强磁场中，该磁场使组织中的氢原子对齐。然后无线电波干扰这种对齐，当原子重新对齐时，它们发出信号，这些信号被捕获并处理成详细的图像。
MRI 的常见用途
大脑和脊髓成像
Detect tumors, strokes, multiple sclerosis, and spinal disorders
关节和肌肉骨骼评估
Evaluate torn ligaments, cartilage damage, and joint abnormalities
心脏成像
Assess heart structure, function, and blood flow
腹部器官评估
Examine liver, kidneys, pancreas, and other abdominal organs
乳腺癌筛查
Supplement mammography for high-risk patients
运动与骨科损伤
Assess ACL, meniscus, and rotator cuff tears
脱髓鞘与脑血管病变
Characterize white matter lesions, aneurysms, and plaques
优势
- ✓无电离辐射暴露
- ✓与CT相比具有优越的软组织对比度
- ✓无需重新定位即可在多个平面成像
- ✓非常适合检测细微的组织变化
局限性
- ⚠与CT相比扫描时间更长
- ⚠过程中噪音较大
- ⚠不适合某些金属植入物或起搏器患者
- ⚠由于封闭空间可能引起幽闭恐惧症
- ⚠比CT或X射线更昂贵
检查准备与流程
检查前
取下所有金属物品，包括珠宝、手表和发夹。如果您有任何金属植入物、起搏器或幽闭恐惧症，请告知医生。您可能会获得耳塞或耳机以减少噪音。
检查中
在扫描期间尽可能保持静止，根据检查区域的不同可能持续15-90分钟。您会听到响亮的敲击或砰砰声。
检查后
除非您因焦虑或幽闭恐惧症而服用了镇静剂，否则通常可以立即恢复正常活动。
相关影像方式
For faster imaging or bone detail, consider CT. For real-time imaging without radiation, ultrasound is an option. Functional MRI (fMRI) can show brain activity.
CT
CT scans use X-rays to create detailed cross-sectional images of the body. They are particularly useful for detecting bone fractures, tumors, and internal bleeding.
Ultrasound
Ultrasound uses sound waves to create real-time images. Commonly used for pregnancy monitoring and examining organs like the heart, liver, and kidneys.
浏览 MRI 术语
探索 MRI 报告中的常见术语，每个术语都包含详细解释、临床意义和相关化验，帮助你读懂影像结果。 化验项目.
ACL Tear
Discontinuous or lax low-signal ACL fibers with abnormal orientation; bone contusions at lateral femoral condyle and posterolateral tibia.
Avascular Necrosis of the Femoral Head
Subchondral serpiginous low-signal rim with inner high-signal on T2 (double-line sign); marrow edema early.
Cerebral Aneurysm
Round or saccular outpouching from cerebral artery, typically at vessel bifurcations
Herniated Disc (Disc Herniation)
Disc material protruding beyond normal disc space margins
Lumbar Spinal Stenosis
Narrowed central canal with crowding of cauda equina; hypertrophic ligamentum flavum and facet arthropathy common.
Meniscus Tear
Linear high-signal cleft reaching articular surface within meniscus; displaced fragments may form a bucket-handle.
Multiple Sclerosis Plaques
Ovoid T2/FLAIR hyperintense lesions oriented perpendicular to ventricles; Dawson’s fingers; active plaques enhance with gadolinium.
Pituitary Adenoma
Iso- to hypointense sellar mass on T1 with variable enhancement; may expand sella or invade cavernous sinus.
Rotator Cuff Tear
Discontinuity or retraction of supraspinatus/infraspinatus tendon with fluid signal in defect; muscle atrophy or fatty change may be present.
White Matter Hyperintensities (WMH)
Bright areas in brain white matter on T2/FLAIR sequences