The left paratracheal reflection
Computed tomography (CT) scanning demonstrated that the left paratracheal (beside the trachea) reflection (reflection of energy or eletromagnetic radiation, such an x-ray, from a surface that is not penetrated) is often visible on chest radiographs when taken from the back (posterior) of a patient. A study was conducted to document reasons for the frequency of this reflection or 'distortion' during CT chest imaging procedures. CT scans of the lung, in the area of the chest where the lungs are in contact with the mediastinum (a cavity separating two organs) to the left of the large artery at the base of the neck (the subclavian artery that supplies blood to the arm) are prone to this reflection, which makes the images difficult to properly assess. When the portion of the lung which is in contact with the left subclavian artery and the portion of the lung which produces the left paratracheal reflection are in the same vertical line of sight, it may not be possible to distinguish separate left subclavian artery and left paratracheal reflections on a chest x-ray taken from the back of a patient (images taken from this position are common). In these cases, one reflection is superimposed over the other to produce a single reflection (image). Several important structures of the body are found in the area of the mediastinum where the left paratracheal reflection is produced (e.g., the left common carotid artery which supplies blood to the brain). Physicians who review these types of CT images should be aware that this reflection of the chest may be distorted by the left paratracheal reflection, therefore obscuring the anatomical structures that they want to view on the CT scan.
Publication Name: Radiology
Tracheal carinal angle and left atrial size
Enlargement of the left atrium, the upper chamber of the heart, usually indicates disorders of the mitral or aortic valves (which regulate blood flow in the heart), clots, tumors, high blood pressure, heart disease, or acute ischemia (transient reduced blood flow to the heart). Because of its position in the body, the left atrium it may be difficult to visualize on an x-ray. Because the left main bronchus (part of the windpipe leading into the lung) rests on the left atrium, enlargement of the atrium would displace the bronchus. Reports that an increased angle of the ridge of the trachea, or windpipe, where it divides into the two bronchi (tracheal carina) indicates left atrial enlargement were validated by electrocardiography on 70 patients and 35 healthy controls. The results show that an enlarged left atrium was predicted by a tracheal carinal angle of 90 degrees or more. An angle of 100 degrees or greater was an extremely accurate predictor. The angle can be measured by different methods, and can be done easily and inexpensively. Refinements in techniques may improve the ability to relate the size of the angle to the size of the left atrium. (Consumer Summary produced by Reliance Medical Information, Inc.)
Publication Name: Archives of Internal Medicine
Who cares: a reflection on healing communities
In many traditional cultures healing practices occurred in the community and involved established rituals. Participants understood roles and shared in a belief in the efficacy of gathering around. In times of grief, to bring babies into the world, or to escort the young through rites of passage, communities gathered. Today organizations are developed to meet needs. They have replaced traditional structures of community in many cases and been very successful. Examples are 12-step programs, support groups and hospice associations. There is confusion, nevertheless, about what to expect of family, friends and faith communities.
Publication Name: Perspectives in Biology and Medicine
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