Radiographic Techniques PDF

Radiographic techniques  Heart and aorta, main branches  :BY Ahmed Jasem Abass  MSC of Medical Imaging Heart and Aorta  Radiography of the heart and aorta is a common examination. It is performed in the routine investigation of heart disease and to assess...

Radiographic techniques  Heart and aorta, main branches  :BY Ahmed Jasem Abass  MSC of Medical Imaging Heart and Aorta  Radiography of the heart and aorta is a common examination. It is performed in the routine investigation of heart disease and to assess heart size and the gross anatomy of the major blood vessels.  Radiographic anatomy  In the postero-anterior radiograph of the chest seen opposite features of the heart and associated vessels have been outlined and labelled. The aortic knuckle is shown as a rounded protrusion slightly to the left of the vertebrae and above the heart shadow. The prominence of the aortic knuckle depends upon the degree of dilation and the presence (or absence) of cardiac disease. It also alters shape as a result of deformities in the thorax, intrinsic abnormalities and with old age. Heart and Aorta  a, superior vena cava  b, ascending thoracic aorta  c, right atrium  d, inferior vena cava  e, left subclavian vein  f, aortic knuckle  g, main pulmonary artery  h, left ventricle. Heart and Aorta Postero-Anterior  The size of the cassette will depend of the size of the patient.  Position of patient and cassette  The patient is positioned erect, facing the cassette and with the chin extended and resting on the top of the cassette.  The median sagittal plane is adjusted perpendicular to the middle of the cassette, with the patient’s arms encircling the cassette. Alternatively, the dorsal aspects of the hands are placed behind and below the hips to allow the shoulders to be rotated forward and pressed downward in contact with the cassette.  The thorax must be positioned symmetrically relative to the film. Postero-Anterior  Direction and centring of the X-ray beam  The horizontal central beam is directed at right-angles to the cassette at the level of the eighth thoracic vertebrae (i.e. the spinous process of T7).  The surface markings of the T7 spinous process can be assessed by using the inferior angle of the scapula before the shoulders are pushed forward.  Exposure is made on arrested full inspiration.  Essential image characteristics  The ideal postero-anterior chest radiograph for the heart and aorta should demonstrate the following:  The clavicles symmetrical and equidistant from the spinous processes.  The mediastinum and heart central and defined sharply.  The costophrenic angles and diaphragm outlined clearly.  Full lung fields, with the scapula projected laterally away from the lung fields. Postero-Anterior Radiological considerations  An artifact increase in the size of the heart may be produced by a number of factors, including:  – poor inspiration  – supine posture lead to a more horizontal cardiac orientation. Left lateral  Position of patient and image receptor  The patient is turned to bring the left side in contact with the image receptor.  The median sagittal plane is adjusted parallel to the receptor.  The arms are folded over the head or raised above the head to rest on a horizontal bar.  The mid-axillary line is coincident with the vertical midline of the receptor, which is adjusted to include the apices and the inferior lobes to the level of the 1st lumbar vertebra.  Direction and location of the X-ray beam  The collimated horizontal beam is directed at right-angles to the middle of the receptor in the mid-axillary line.  Exposure is made on arrested full inspiration. Left lateral  Essential image characteristics  The thoracic vertebrae and sternum should be lateral and demonstrated clearly.  The arms should not obscure the heart and lung fields.  The anterior and posterior mediastinum and heart are defined sharply and the lung fields are seen clearly.  The costophrenic angles and diaphragm should be outlined clearly.  Radiological considerations  A lateral radiograph may help to locate cardiac or pericardial masses, e.g. left ventricular aneurysm and pericardial cyst. Also these are assessed better by echocardiography or CT/MRI Left lateral Left lateral Thank You