Additional information | Anatomy of the cardiovascular system | Anatomy

Box for Kaposi sarcoma versus Bartonella henselae: Kaposi’s sarcoma is a malignant proliferation of endothelial cells associated with HHV 8 virus. Bacillary angiomatosis is an infective, vasoproliferative disorder caused by Bartonella henselae. Both conditions are seen in immunocompromised and HIV positive patients. They both present as purple to red colored, raised nodules or plaques affecting the skin and internal organs. They can be distinguished by histopathology. Bacilli will be seen only in bacillary angiomatosis while spindle cells will be seen in Kaposi’s sarcoma.
Cardiac Silhouette On an antero-posterior (AP) or postero-anterior (PA) view of the chest, the borders of the heart have common landmarks:
1. Right Border: Formed by the right atrium which is in between the SVC and IVC
2. Left Border: Formed by the left ventricle & portion of the left auricle
3. Anterior Surface or Sternocostal Surface: Mainly the right ventricle (not seen on AP view)
4. Inferior Border: Combination of the right & left ventricles
Aortic Knob
The aortic knob should be visualized in the normal chest radiograph around the level of T3 to T4 or just lateral to the carina. In patients with aortic aneurysm, this can be the area contributing to the “widened mediastinum”.
Costocardiac & Costophrenic Angles: The costocardiac angles (as well as the costophrenic angles) should be fairly sharp and well defined if the patient does not have significant effusions or pulmonary edema. If they are blunted or lost, you should be concerned for the presence of fluid in the lung or a mass obstructing the view. Additional imaging with a chest CT may sometimes be warranted if the etiology is not clear from the patient’s presentation.