Lecture 6: Anatomy of the Bony Thorax PDF

Anatomy Bony thorax consists of ◦Sternum (anteriorly) ◦Thoracic vertebrae (Posteriorly) ◦12 pairs of ribs connecting the sternum to the vertebral column Sternum flat bone divided into 3 parts ◦Manubrium (upper portion) ◦Body (middle) ◦Xiphoid process (inferio...

Anatomy Bony thorax consists of ◦Sternum (anteriorly) ◦Thoracic vertebrae (Posteriorly) ◦12 pairs of ribs connecting the sternum to the vertebral column Sternum flat bone divided into 3 parts ◦Manubrium (upper portion) ◦Body (middle) ◦Xiphoid process (inferior) About 7 inches in adults Ribs Ribs are numbered based on the thoracic vertebra so which they attach, starting from top down true ribs (1-7) ◦Connect directly to sternum via Costocartilage False ribs (8-12) ◦8-10: connect indirectly to sternum via costocartilage of rib 7 ◦11-12: floating ribs with no connection to sternum, lack costocartilage Palpable landmarks jugular notch ◦Level of T2-T3 vertebrae Sternal angle (Manubriosternal joint) ◦Level of intervertebral disk between T4 and T5 Xiphoid process ◦Inferior tip of sternum ◦Located T9-T10 Inferior rib (costal) angle ◦Aka inferior cosatal margin ◦L2-L3 ◦Locating lower ribs and abdomen Sternal rib articulations first 7 pairs of ribs (true ribs) connect to the sternum through costocartilage ◦Sternum has 7 facets (depressions) laterally along manibrium and body of sternum that accept costocartilage for each rib attachment First rib ◦Below jugular notch Second rib ◦Connects at level of Sternal angle 3-7 ◦Connect directly to body of sternum  8-10 (false ribs ◦Connects to costocartilage 7 that connects to the sternum ◦Doesn’t connect directly to sternum Sternum RAO position Tech factors SID: 40 inches IR size: 10 x 12 inches, portrait Grid 3-4 second exposure if breathing technique is used KVp: 70-85 CR Perpendicular to IR Center of sternum to left of midline and midway between jugular notch and Xiphoid process Anatomy demonstrated Sternum Superimposition Sternum superimposed on heart shadow Sternum not superimposed by vertebrae Lateral Sternum: R or L Tech factors SID: 40 inches IR size: 10 x 12 inches, portrait Grid KVp: 75-85 CR Perpendicular to IR Center of sternum (midway between jugular notch and Xiphoid process) Respiration Suspend respiration on inspiration Anatomy demonstrated Entire sternum Superimposition Sternum with no superimposition of ribs Sternoclavicular Joints PA Sternoclavicular joints Tech factors SID: 40 inches IR size: 8 x 10 inches, landscape Grid KVp: 75-85 CR Perpendicular Midsagittal plane at level of T2-T3, or 3 inches distal to vertebra prominens (spinous process of C7) Respiration Suspend on expiration Anatomy demonstrated Bilateral left and right SC joints Lateral aspect of manubrium and medial portion of clavicles lateral through superimposing ribs and lungs Anterior obliques (LAO, RAO): SC Joints Tech factors SID: 40 inches IR size: 8 x 10 inches, landscape Grid KVp: 75-85 CR Perpendicular to level T2-T3, or 3 inches distal to vertebra prominens 1-2 inches lateral to midsagittal plane Respiration Suspend on expiration Anatomy demonstrated Manibrium Medial portion of clavicles Sternoclavicular joint best demonstrated on downstide SC joint on upside will be foreshortened Superimposition Downside SC joint with no superimposition of vertebral column/manibrium Ribs AP Ribs: Bilateral posterior SID: 40 inches; bilateral ribs a 72 inch can be used to minimize magnification IR size: 14 x 17 inches, landscape Grid KVp: 75-85 CR Perpendicular to IR Midsagittal plane at level 3/4 inches below jugular notch Respiration Suspend on deep inspiration for above diaphragm Suspend on full expiration for ribs below diaphragm Anatomy demonstrated Above diaphragm: ribs 1-9 Below diaphragm: ribs 10-12 PA bilateral anterior Ribs Tech factors SID: 40 inches; bilateral ribs a 72 inch can be used to minimize magnification IR size: 14 x 17 inches, landscape Grid KVp: 75-85 CR Perpendicular to IR Midsagittal plane at level of T7 Respiration Inspiration Anatomy demonstrated Ribs 1-9 above diaphragm Posterior Oblique (RPO, LPO) Ribs Posterior-lateral injury: posterior oblique positions, affected side toward IR Anterior-lateral injury: anterior oblique positions, affected side away from IR Tech factors SID: 40 inches; 72 inch can be used to minimize magnification IR size: 14 x 17 inches, landscape Grid KVp: 75-85 CR Perpendicular to IR Above diaphragm ◦Level 3/4 inches below jugular notch (T7) for posterior oblique or 7-8 inch’s below vertebra prominens (T7) for anterior oblique Below diaphragm ◦Midway between Xiphoid process and lower rib margin Respiration Above: Inspiration Below: expiration Anatomy demonstrated Above: Ribs 1-9 Below: ribs 10-12 Axillary ribs in profile with spine shifted away from area of interest