胸片读片与心影改变.ppt

胸片阅读与心影改变 谭洪毅 X-rays- describe radiation which is part of the spectrum which includes visible light, gamma rays and cosmic radiation. Unlike visible light, radiation passes through stuff. When you shine a beam of X-Ray at a person and put a film on the other side of them a shadow is produced of the inside of their body. Different tissues in our body absorb X-rays at different extents: Bone- high absorption (white) Tissue- somewhere in the middle absorption (grey) Air- low absorption (black) Be systematic : 1) Check the quality of the film Film Quality First determine is the film a PA or AP view. PA- the x-rays penetrate through the back of the patient on to the film AP-the x-rays penetrate through the front of the patient on to the film. All x-rays in the PICU are portable and are AP view Film Quality (cont) Was film taken under full inspiration? -10 posterior ribs should be visible. Why do I say posterior here? When X-ray beams pass through the anterior chest on to the film Under the patient, the ribs closer to the film (posterior) are most apparent. A really good film will show anterior ribs too, there should Be 6 to qualify as a good inspiratory film. Quality (cont.) Is the film over or under penetrated if under penetrated you will not be able to see the thoracic vertebrae. Quality (cont) Check for rotation Does the thoracic spine align in the center of the sternum and between the clavicles? Are the clavicles level? Verify Right and Left sides Gastric bubble should be on the left X线 一、心胸比:心脏横径与胸廓横径之比. 正常值:0.5,分为三度,0.51~0.55 为轻度、0.56~0.60为中度、大于 0.60为高度增大。 缺点:受体型,横膈位置影响大,横位心及垂位心较大误差;不能反映心脏前后径的增大。 心胸比测量示意图一 心胸比等于：T1＋T2/Th； T1：右心缘距中线的最大距离； T2：左心缘距中线的最大距离； Th：胸廓横径，以通过右膈顶上缘测量胸廓横径为准 。 摘自临床心脏x线诊断学刘玉清主编 B：心脏横径，两心缘最凸点垂直线之间的距离。 A：胸廓最大横径。 心胸比：B/A 摘自影像诊断学 [美]Peter Armstrong著 邱健泰等译 心胸比测量示意图二 二、心高比： 取右心房与大血管交点至右心膈角水平线垂直距离为右心房高，取主动脉弓项至右心膈角水平线垂直距离为心高，两者之比右心房一心高比率。平均0.46 ± 0.04,反映右心房增大.。 三、主，肺动脉的测量 1．升主动脉宽径(A1)，以升主动脉