Helen Murphy SCC Allied Health Radiology Program More CXR…
Views: • PA Upright/ Left Lateral Upright (already talk about) • AP upright chest • Supine chest • Cross-Table Left Lateral • AP/PA Lordotic chest • Decub Chest • Portable Chest • Dual Energy Chest (SHMC)
On all CXRS…. • The lung markings, diaphragms, heart borders, hilum, greater vessels, and bony cortical outlines are sharply defined. So use high KVP (sufficient to penetrate the chest structures and provides the contrast scale necessary to visualize the lung details.) and a grid ( to absorb scatter). • Sharply defined recorded details are also obtained when patient respiration and body movements are halted(So NO MOTION!!!) • The least amount of object “image receptor distance (OID) is maintained. This why PA is better than AP (patient’s heart is closer to IR). • Use a 72-inch (183-cm) source “image receptor distance” (SID) to decrease the magnification of the heart.
CONT… • The time of examination, degree of patient elevation( supine semi-upright…) and if done AP should be on the image. • Indicating the time of day on the image is especially important if the patient's progress is being followed and multiple chest images are to be taken on the same day. This is done automatically on CR and DR( but is the time right?). Knowledge of the degree of elevation helps the reviewer determine the exact amount of fluid in the patient's lungs.
Structures shown: Entire lung field • An AP projection is somewhat similar to the PA projection. AP being farther from the IR, the heart and great vessels are magnified as well as engorged, and the lung fields appear shorter because abdominal compression moves the diaphragm to a higher level. The clavicles are projected higher, and the ribs assume a more horizontal appearance
PA AP Scapulas are in the way!
Upright Supine Heart appears larger
Why take a portable CXR? • Patient is not stable or too sick to come down stairs • Check for position of lines and tubes • Check for complications from lines and tubes • Sudden onset of chest pain and or shortness of breath • To check for a Pneumothorax (upright is best!) • Air embolism from line
Another way to show air-fluid levels: To demonstrate precise air-fluid levels when pleural effusion is suspected, chest images should be taken with the patient upright and the x-ray beam horizontal. With this position, the air rises and the fluid gravitates to the lowest position, creating an air-fluid separation. This separation is identified as a decrease in density on the image wherever the dense fluid is present in the lung field. The true amount of fluid cannot be discerned on an image unless the fluid is level; in the slanted position the chest may appear to have no fluid. When the patient is supine, the fluid is evenly spread throughout the lung field, preventing visualization of fluid levels.
The same patient with tube angle and without Without With 25 degrees
Please: • Remove all patient monitoring lines that can be removed or shift them out of the lung field! When patient monitoring lines remain within the lung field, they may obscure lung details or the one line we are looking for. • Use a grid whenever possible, especially on larger patients. A grid is not always employed in portable imaging. Why? because it is difficult to ensure that the grid and central ray are aligned accurately, which could lead to grid cutoff. When no grid is used, a lower kVp technique is needed to prevent excessive scatter radiation from reaching the IR and hindering contrast. Although the lower kVp will sufficiently penetrate the lung field, it seldom provides enough penetration to allow visualization of structures within and behind the heart shadow
Same patient demonstrating a fluid-type pathologic condition Non grid Grid
When a chest x-ray is used to evaluate the placement of apparatus positioned within the mediastinal region, the heart shadow should be penetrated. The accurate placement of these lines cannot be evaluated without heart penetration. Accomplish this penetration by increasing the kVp. The resulting image will demonstrate a penetrated heart shadow with the thoracic vertebrae, posterior ribs, and chest lines, clearly demonstrated through it. The amount of scatter radiation reaching the IR will also increase, resulting in overall lower image contrast (Gray &UGLY!!) So grid use would be helpful!!!!
Just like a lateral chest just done x-table • Still need the entire lung field on • Use for post pacemaker patients and babies
Pulmonary Apices Positions: • AP axial projection -Lordotic position -Lindbolm method (pt leans backwards to the film) • AP axial projection ( pt AP angle tube 15-20 up) • PA axial projection ( pt PA angle tube 15-20 up) • PA axial projection- Lordotic position- Fleischer method (pt leans backwards away from film) • Not shown (no pictures in book)
Structures shown: • Demonstrate the apices free from superimposion of clavicles.
AP Axial Lordotic Position
Positions: • Rt lateral Decubitus (right side down) • Lt lateral Decubitus (left side down) • *For fluid: place patient on affected side • * For air: place patient on the unaffected side • *Trendelenburg helps show fluid levels better • * Can be done AP or PA
What does it show: • Demonstrates the change in fluid position and reveals any previously obscured pulmonary areas or, in the case of pneumothorax (air or gas in the pleural space), the presence of any free air. • Done on pts with chest tubes to check fluid levels
AP projection, left lateral decubitus position .The arrows indicate the air-fluid level (air on the side up). I would show both sides AP projection, right lateral decubitus position. Arrows showing a fluid level (the down side) . Note the fluid in the lung fissure (arrowhead)
Obliques of the Chest • RAO/LAO: 45 degree obliquesdemonstrate the side farthest from the IR (LAO shows right side) • RPO/LPO:45 degree obliques demonstrate the side closestfrom the IR (LPO shows the left side)
LAO Chest : Demonstrate the side farthest from the IR (right side) RT side demonstrated
LPO Chest: demonstrate the side closest from the IR (left side) Left side is demonstrated
Dual energy Chest • Done at SHMC on all PICC Line patients • One exposure (long one) but three images! • First image normal chest • Second image ribs blurred • Third image just bones
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Some lines found in the in chest: Central venous (CV line) catheters also known as Peripherally inserted central catheters (PICC) or Ports , pulmonary arterial line also known as a Swan-Ganz catheter
Central venous catheters are inserted into the subclavian vein or a more peripheral vein in the upper extremity are extremely useful for measurement of the central venous pressure (CVP) and for providing a conduit for the rapid infusion of fluid or chronic hyperalimentation. They allow for infusion of substances that are too toxic for peripheral infusion, such as for chemotherapy, total parenteral nutrition, dialysis, or blood transfusions. • So that the CVP may be correctly measured, the catheter must be located with in the true central venous system, beyond all the valves, which interfere with direct transmission of the right arterial pressure to the catheter. • We would like it to be where the brachiocephlic veins join to form the superior vena cava or within the superior vena cava itself approximately 2 to 3 cm above the right atrial junction • Medial to the anterior border of the first rib
Images taken for CV line placement should demonstrate adequate density and penetration to visualize the line and lung conditions that may result if perforation occurs during line insertion, such as pneumothorax or hemothorax.
Complications: • Pneumothorax • Infections • Air embolism • Hemorrhage • Arrhythmia
Catheter with it’s tip in the pleural space. A right subclavian catheter, perforated the superior vena cava and eroded into the right pleural space. Note the tip of the catheter projecting beyond the right border of the mediastinum (arrow). The direct infusion of parenteral fluid into the pleural space has led to a large right hydrothorax This is why it is very important to have a x-ray before use!
Broken PICC catheter. The sheared-off portion of the catheter (arrow) is located in the left lower lobe.
Pulmonary arterial line (Swan-Ganz catheter): The pulmonary arterial line is similar to the Central venous line but is longer. It is used to measure atrial pressures, pulmonary artery pressure, and cardiac output. The measurements obtained are used to diagnose ventricular failure and monitor the effects of specific medication, exercise, and stress on heart function. The pulmonary arterial line is inserted in the subclavian, internal or external jugular, or femoral vein and is advanced through the right atrium into the pulmonary artery . Images taken for pulmonary arterial line placement should demonstrate adequate density and penetration to visualize the line and mediastinal structures to determine adequate placement and lung conditions that may result if perforation occurs during line insertion, such as pneumothorax or hemothorax.
More things put into a chest: • Endotracheal tube (ET): The ET is a stiff, thick-walled tube that is used to inflate the lungs: They are inserted through the mouth into the trachea as a means of establishing or opening an air way • It should be 5-7 cm above the tracheal bifurcation(carina) • Why take a cxr? To check for proper placement of tube and to check for pneumonia or pneumothorax • 20% go into right main bronchus this will cause collapse of the left lung • A tube to high will cause air to enter the stomach, this could cause regurgitation of gastric contents into the lungs, which could lead to aspiration pneumonia. • Films taken daily to check for movement • Patient could get a tension pneumothorax from the pressure of the ventilation machine.
Distal end of endotracheal tube with cuff deflated (1) A, Adult endotracheal tube. side hole end hole • Tracheotomy tube. • ( C, Pediatric endotracheal tube; note the absence of cuff.
Anteroposterior mobile chest projection showing trachea (dotted line) endotracheal tube nasogastric tube carina cardiac monitor wires