Routine Radiology of the Trauma Patient Chantal VCA 440

Introduction The purpose of this presentation is to remind us that though fractures resulting from HBC or HRS can be immediately eye-catching, once stabilized it may be the least of the animals concern. What is not immediately apparent is that this patient could be on the verge of a cardiorespiratory crisis due to a tension pneumothorax or hemorrhaging into it’s abdomen due to a ruptured spleen. Thus, it is essential that a series of survey radiographs be taken and the following are the major problems to watch for:

What to look for in the thorax Pulmonary contusions Hemothorax Pneumomediastinum Pneumothorax Traumatic diaphragmatic hernia In the thorax, there are 5 more common problems secondary to high velocity trauma, such as: pulmonary contusions, hemothorax, pneumomediastinum, pneumothorax and traumatic diaphragmatic hernia.

Pulmonary Contusions How it happens: Radiographic Signs: What’s next? Hemorrhage into the lung parenchyma Tearing and crushing injury Radiographic Signs: Patchy, focal or generalized Alveolar pattern May not be visible right away What’s next? Be conservative with fluids Respiratory support +/- Coagulation tests Direct trauma to the chest can cause tearing and crushing injuries to the lungs, resulting in bleeding into the parenchyma. These pulmonary contusions, radiographically, will appear as patchy, focal or generalized, areas of aveolar pattern. However they may not be visible immediately post-trauma. If necessary to treat for shock, be especially conservative with fluids as this may result in pulmonary edema, as well as hemorrhage due to the preexisting capillary damage. Respiratory support may also be necessary due to the imbalance in ventilation and perfusion caused by the hemorrhage.

Pulmonary Contusions Here’s another example of pulmonary contusions, where the hemorrhage is more localized in proximity to the adjacent rib fractures.

Hemothorax

Hemothorax How it happens: Radiographic signs: What’s next? Trauma to arteries /veins Damage to heart, lungs, thymus, or diaphragm Ruptured herniated abdominal viscera Radiographic signs: Pleural effusion Diffuse or ventral Scalloping/fissures What’s next? Thoracocentesis +/- Surgical exploration Oxygen, transfusion, fluids Direct trauma to the chest could also cause damage to any number of vessels or structures within the thorax resulting in hemorrhaging into the pleural cavity. Radiographically, this would appear as pleural effusion differing in severity from mild scalloping of the ventral lungs and interlobar fissures to a diffuse radiopacity silhouetting with the heart. With a case as such as this, it would be important to drain the fluid via thoracocentesis and provide support.

Pneumomediastinum How it happens: Radiographic signs: What’s next? Ruptured alveoli, trachea, or esophagus Tracheal avulsion Radiographic signs: Distinction of structures normally not seen Tracheal wall outlined SQ emphysema What’s next? Repair rents Monitor for progression Wrenching or perforation of the neck can result in tracheal or esophageal rupture causing leakage of air into the folds of the mediastinum and fascial planes of the neck. Also trauma to the chest can rupture alveoli or avulse the trachea from the mainstem bronchi. Air in the mediastinum is evident as it allow distinction of normally unseen structures such as the azygous vein and the tracheal walls. It is important to recognize this conditon as it may progress to a hazardous pneumothorax.

Pneumomediastinum Here is the extension of the pneumomediastinum throughout the neck. This view can be helpful in localizing the source of incoming air.

Pneumothorax

Pneumothorax How it happens: Radiographic signs: What’s next? Chest wall rent Lung rupture Extension of pneumomediastinum Radiographic signs: Retracted lungs +/- collapse Raised heart +/-Small heart +/-flat caudal diaphragm +/-mediastinal shift What’s next? Thoracocentesis Without a doubt, one of the most importing things to recognized radiographically is pneumothorax, especially when under tension. This can occur due to rents made in the chest wall, ruptured lungs or preexisting bulla, or as an extension of a pneumomediastinum as mentioned before. On film, this will be recognized by radiolucent spaces between the chest wall and lung (symbolizing retraction), a raised cardiac silhouette, and possibly collapsed lungs, displaced mediastinum or diaphragm, and decreased heart size. Upon visualizing a pneumothorax it is important to drain the air off the chest by thoracocentesis, especially if under tension.

Pneumothorax This portrays a good example of lung collapse and cardiac elevation from the sternum.

Traumatic Diaphragmatic Hernia How it happens: Rapid increase in intra- abdominal pressure Rent in the muscular portion Radiographic signs: +/-Pleural effusion +/-Gas filled loops, liver stomach,spleen +/-Loss of diaphragmatic outline +/-Asymmetric on VD/DV +/-Missing viscera from abdomen What’s next? Contrast study to definitively diagnose Finally, when surveying the thorax, it is important to note the presence of any traumatic diaphragmatic hernias. This can be seen by complete or partial loss of the diaphragmatic outline, possibly visualizing visceral structures within the thorax or noticing missing viscera from the abdomen, and noting the asymmetry of the diaphragm on vd/dv. However, if suspected, hernias should be confirmed by performing contrast studies such as the UGI, as seen in the next slide.

The UpperGI You can now see the small intestines entering the thorax.

What to look for in the abdomen Hemoperitoneum Renal avulsion Uroperitoneum Traumatic hernias Conditions that may be overlooked in the abdomen could be : hemoabdomen, renal avulsion, uroperitoneum and traumatic hernias.

Hemoperitoneum How it happens: Radiographic signs: What’s next? Ruptured spleen Ruptured liver Disrupted vasculature Avulsed bladder Radiographic signs: Peritoneal effusion Focal or diffuse Decreased serosal detail What’s next? U/S Abdominocentesis Direct trauma to the abdomen can cause rupture and subsequent hemorrhage of viscera, such as the spleen or liver, or disruption of intra-abdominal vasculature. This would result in peritoneal effusion which would indicated radiographically by a focal or diffuse decrease in serosal detail. The hemorrhage can be definitively diagnosed by abdominocentesis and localized using ultrasound.

Hemoperitoneum This is the DV of the last case depicting a focal area of decreased serosal detail in the left abdomen in the region of the spleen.

Renal Avulsion Radiographic signs: What’s next? Focal decreased serosal detail Missing kidney Mass in caudal abdomen What’s next? U/S On occasion, an animal could be traumatized in such a way to cause avulsion of a kidney from the body wall. Radiographically, this may not be diagnostic, though a decrease in serosal detail may be noted as well as the disappearance of the kidney. Ultrasound would be required to further evaluate.

Renal Avulsion This was the U/S taken of this cat. As you can see the kidney is sitting by the bladder.

Renal Avulsion Right Kidney Left (avulsed) Kidney With the doppler, it can be noted that the avulsed kidney has been detached from its vasculature.

Uroperitoneum How it happens: Radiographic signs: What’s next? Ruptured bladder Avulsed/torn ureter Urethral tear Radiographic signs: Diffuse decreased serosal detail Focal detail loss in the RPS What’s next? Abdominocentesis IVP (EU) Cystogram Urethrogram Commonly associated with pelvic fractures, uroperitoneum is radiographically similar to hemoabdomen, though can be differentiated via abdominocentesis. However, this condition can be caused by either ruptured bladder, avulsed or torn ureters, or torn urethra. Thus contrast studies are imperative to further localize the problem.

Ruptured Bladder The urethrocystogram Contrast can be seen leaking from the bladder.

Avulsed or Ruptured Ureter The Excretory Urogram: The ureter appears to have avulsed from the trigone of the bladder in this case, though could also occur at the renal pelvis or as a midbody tear.

Ruptured Urethra The Urethrogram Note the disruption of the urethra.

Traumatic Hernia How it happens: Radiographic signs: What’s next? Rapid increase in intra- abdominal pressure Rent in the body wall, inguinal canal, or perineal wall Radiographic signs: Extra-abdominal mass Disruption of the body wall +/-Containing gas-filled loops of intestines +/-Missing abdominal viscera What’s next? U/S mass Surgical repair As with diaphragmatic hernias, the rapid increase in intra-abdominal pressure can cause a rent in the musculature of the body wall. Less commonly, these can also occur in the inguinal or perineal regions. These will appear as an extra-abdominal mass, possibly containing abdominal viscera which may appear radiographically. Ultrasound can be used to further identify contents of the hernia. Surgical repair will be necessary.

Traumatic Hernia Here’s an example of body wall herniation.

In summary Breath Stabilize Don’t get dazzled by an impressive fracture Get ALL the info