Trauma CT Saves Lives - If Scans Are Read in Time

SAN FRANCISCO – With radiology assistance often taking hours, more physicians should know the basics of reading a trauma CT to identify injuries that require immediate action, Dr. Andrew D. Perron said.

"At 3 a.m., I have to know without calling someone whether I need to get moving," said Dr. Perron, an emergency physician at Maine Medical Center, Portland. It is crucial to be able to identify which diagnoses could kill a patient within an hour, so focus on detecting a handful of potentially life-threatening injuries in the head, chest, abdomen, and pelvis, he said at the Scientific Assembly of the American College of Emergency Physicians.

For trauma victims, CT scans have become almost automatic. Currently in the United States, 60-70 million CT scans are conducted each year, compared with only 3 million in 1980, Dr. Perron said. A quarter of the scans are of the head.

When reading a CT of the head, look for epidural hematoma, subdural hematoma, skull fracture, contusions, head pressure and shift, and neck injuries. An epidural hematoma will be lens shaped and does not cross the sutures. A clot will appear as bright white on the scan; if an area is on its way to clotting, it will be gray. Epidural hematomas have low mortality if the patient is treated before he or she loses consciousness.

Subdural hematomas are sickle-shaped and do cross the sutures but not the midline. Subdurals have an 80% mortality rate. Even if a neurosurgeon suctions out the clot, the brain may not recover, Dr. Perron said.

Any area of the skull can sustain a fracture, but skull fractures sometimes aren’t readily visible on plain film or CT. The give-away on imaging is if there is blood instead of air in the mastoid cells, he said.

Although brain contusions are not readily treatable, it is important to know they are there, Dr. Perron said. A contusion will appear as a high-density area on the scan. They commonly result from a sudden deceleration, as in a motor vehicle collision. CT scans can be used to show high pressure within the skull, but there is divergence in the literature about CT’s true utility for these cases, Dr. Perron said.

In the neck, look for fracture and dislocation. CT is 98% sensitive for neck fractures and is especially good for diagnosing fractures located either high or low in the neck. Vertebral body fractures are the most common and account for about a third of neck fractures. Axial views provide the most data on the state of the spinal canal, but a coronal view is easier to read if the physician is more experienced with plain x-rays.

Dislocation is most common, but easier to miss, at C5-6 and C6-7. Dislocations are usually accompanied by torn ligaments. The injury comes from a rotational deceleration in most cases. Vascular injury can occur with dislocation or subluxation, with an attendant risk for dissection. An angiogram should be considered for patients with a C1-3 fracture and subluxation or fracture of the foramen transversarium.

In the chest, the main concerns are aortic injury, pneumothorax, and hemothorax. Like contusions, aortic injuries often are caused by sudden deceleration. Most patients with an aortic injury die in the field. If they survive to the hospital and are scanned, leaking contrast material seen on imaging indicates a ruptured aorta, Dr. Perron said.

A chest x-ray can miss a small pneumothorax, but they are easy to see on CT, with a black space demonstrating where air is outside the lung. A hemothorax cannot be detected by x-ray until at least 250 cc of blood has accumulated, but CT is more sensitive for these as well.

The spleen, liver, kidneys, pancreas, and blood in the abdomen are the areas of greatest concern in abdominal trauma. When scanning the abdomen, Dr. Perron generally uses intravenous contrast because it helps identify the major blood vessels and shows active bleeding. He starts with a supine and coronal view, as axial orientations are more difficult to read.

There should never be blood visible in the middle of the spleen. The liver has more vascularity on a normal view. Lacerations are the most common injury in the liver, and lacerations to the kidneys are also often seen. CT may detect an absence of blood flow to the liver or kidney, indicating severe injury. The main issue with these organs is to be sure they are in one piece and functioning.

The sensitivity of CT is only 68% for pancreatic injuries. This pancreas can be damaged when it is compressed against the spine, which may occur in a bicycle- or sports-related impact. CT can be used to spot active bleeding; the active extravasation of IV contrast is the hallmark, but it may be subtle.

In the pelvis, fractures and other bony injuries and free fluid are the biggest concerns. Pelvic fractures, which are generally easy to see on imaging, suggest that the body sustained a large amount of force. Free fluid in the pelvis can indicate a solid organ injury, a mesenteric injury, a bowel injury, or even a preexisting condition such as ascites.

Dr. Perron reported no conflicts of interest.

SAN FRANCISCO – With radiology assistance often taking hours, more physicians should know the basics of reading a trauma CT to identify injuries that require immediate action, Dr. Andrew D. Perron said.

"At 3 a.m., I have to know without calling someone whether I need to get moving," said Dr. Perron, an emergency physician at Maine Medical Center, Portland. It is crucial to be able to identify which diagnoses could kill a patient within an hour, so focus on detecting a handful of potentially life-threatening injuries in the head, chest, abdomen, and pelvis, he said at the Scientific Assembly of the American College of Emergency Physicians.

For trauma victims, CT scans have become almost automatic. Currently in the United States, 60-70 million CT scans are conducted each year, compared with only 3 million in 1980, Dr. Perron said. A quarter of the scans are of the head.

When reading a CT of the head, look for epidural hematoma, subdural hematoma, skull fracture, contusions, head pressure and shift, and neck injuries. An epidural hematoma will be lens shaped and does not cross the sutures. A clot will appear as bright white on the scan; if an area is on its way to clotting, it will be gray. Epidural hematomas have low mortality if the patient is treated before he or she loses consciousness.

Subdural hematomas are sickle-shaped and do cross the sutures but not the midline. Subdurals have an 80% mortality rate. Even if a neurosurgeon suctions out the clot, the brain may not recover, Dr. Perron said.

Any area of the skull can sustain a fracture, but skull fractures sometimes aren’t readily visible on plain film or CT. The give-away on imaging is if there is blood instead of air in the mastoid cells, he said.

Although brain contusions are not readily treatable, it is important to know they are there, Dr. Perron said. A contusion will appear as a high-density area on the scan. They commonly result from a sudden deceleration, as in a motor vehicle collision. CT scans can be used to show high pressure within the skull, but there is divergence in the literature about CT’s true utility for these cases, Dr. Perron said.

In the neck, look for fracture and dislocation. CT is 98% sensitive for neck fractures and is especially good for diagnosing fractures located either high or low in the neck. Vertebral body fractures are the most common and account for about a third of neck fractures. Axial views provide the most data on the state of the spinal canal, but a coronal view is easier to read if the physician is more experienced with plain x-rays.

Dislocation is most common, but easier to miss, at C5-6 and C6-7. Dislocations are usually accompanied by torn ligaments. The injury comes from a rotational deceleration in most cases. Vascular injury can occur with dislocation or subluxation, with an attendant risk for dissection. An angiogram should be considered for patients with a C1-3 fracture and subluxation or fracture of the foramen transversarium.

In the chest, the main concerns are aortic injury, pneumothorax, and hemothorax. Like contusions, aortic injuries often are caused by sudden deceleration. Most patients with an aortic injury die in the field. If they survive to the hospital and are scanned, leaking contrast material seen on imaging indicates a ruptured aorta, Dr. Perron said.

A chest x-ray can miss a small pneumothorax, but they are easy to see on CT, with a black space demonstrating where air is outside the lung. A hemothorax cannot be detected by x-ray until at least 250 cc of blood has accumulated, but CT is more sensitive for these as well.

The spleen, liver, kidneys, pancreas, and blood in the abdomen are the areas of greatest concern in abdominal trauma. When scanning the abdomen, Dr. Perron generally uses intravenous contrast because it helps identify the major blood vessels and shows active bleeding. He starts with a supine and coronal view, as axial orientations are more difficult to read.

There should never be blood visible in the middle of the spleen. The liver has more vascularity on a normal view. Lacerations are the most common injury in the liver, and lacerations to the kidneys are also often seen. CT may detect an absence of blood flow to the liver or kidney, indicating severe injury. The main issue with these organs is to be sure they are in one piece and functioning.

The sensitivity of CT is only 68% for pancreatic injuries. This pancreas can be damaged when it is compressed against the spine, which may occur in a bicycle- or sports-related impact. CT can be used to spot active bleeding; the active extravasation of IV contrast is the hallmark, but it may be subtle.

In the pelvis, fractures and other bony injuries and free fluid are the biggest concerns. Pelvic fractures, which are generally easy to see on imaging, suggest that the body sustained a large amount of force. Free fluid in the pelvis can indicate a solid organ injury, a mesenteric injury, a bowel injury, or even a preexisting condition such as ascites.

Dr. Perron reported no conflicts of interest.

SAN FRANCISCO – With radiology assistance often taking hours, more physicians should know the basics of reading a trauma CT to identify injuries that require immediate action, Dr. Andrew D. Perron said.

"At 3 a.m., I have to know without calling someone whether I need to get moving," said Dr. Perron, an emergency physician at Maine Medical Center, Portland. It is crucial to be able to identify which diagnoses could kill a patient within an hour, so focus on detecting a handful of potentially life-threatening injuries in the head, chest, abdomen, and pelvis, he said at the Scientific Assembly of the American College of Emergency Physicians.

For trauma victims, CT scans have become almost automatic. Currently in the United States, 60-70 million CT scans are conducted each year, compared with only 3 million in 1980, Dr. Perron said. A quarter of the scans are of the head.

When reading a CT of the head, look for epidural hematoma, subdural hematoma, skull fracture, contusions, head pressure and shift, and neck injuries. An epidural hematoma will be lens shaped and does not cross the sutures. A clot will appear as bright white on the scan; if an area is on its way to clotting, it will be gray. Epidural hematomas have low mortality if the patient is treated before he or she loses consciousness.

Subdural hematomas are sickle-shaped and do cross the sutures but not the midline. Subdurals have an 80% mortality rate. Even if a neurosurgeon suctions out the clot, the brain may not recover, Dr. Perron said.

Any area of the skull can sustain a fracture, but skull fractures sometimes aren’t readily visible on plain film or CT. The give-away on imaging is if there is blood instead of air in the mastoid cells, he said.

Although brain contusions are not readily treatable, it is important to know they are there, Dr. Perron said. A contusion will appear as a high-density area on the scan. They commonly result from a sudden deceleration, as in a motor vehicle collision. CT scans can be used to show high pressure within the skull, but there is divergence in the literature about CT’s true utility for these cases, Dr. Perron said.

In the neck, look for fracture and dislocation. CT is 98% sensitive for neck fractures and is especially good for diagnosing fractures located either high or low in the neck. Vertebral body fractures are the most common and account for about a third of neck fractures. Axial views provide the most data on the state of the spinal canal, but a coronal view is easier to read if the physician is more experienced with plain x-rays.

Dislocation is most common, but easier to miss, at C5-6 and C6-7. Dislocations are usually accompanied by torn ligaments. The injury comes from a rotational deceleration in most cases. Vascular injury can occur with dislocation or subluxation, with an attendant risk for dissection. An angiogram should be considered for patients with a C1-3 fracture and subluxation or fracture of the foramen transversarium.

In the chest, the main concerns are aortic injury, pneumothorax, and hemothorax. Like contusions, aortic injuries often are caused by sudden deceleration. Most patients with an aortic injury die in the field. If they survive to the hospital and are scanned, leaking contrast material seen on imaging indicates a ruptured aorta, Dr. Perron said.

A chest x-ray can miss a small pneumothorax, but they are easy to see on CT, with a black space demonstrating where air is outside the lung. A hemothorax cannot be detected by x-ray until at least 250 cc of blood has accumulated, but CT is more sensitive for these as well.

The spleen, liver, kidneys, pancreas, and blood in the abdomen are the areas of greatest concern in abdominal trauma. When scanning the abdomen, Dr. Perron generally uses intravenous contrast because it helps identify the major blood vessels and shows active bleeding. He starts with a supine and coronal view, as axial orientations are more difficult to read.

There should never be blood visible in the middle of the spleen. The liver has more vascularity on a normal view. Lacerations are the most common injury in the liver, and lacerations to the kidneys are also often seen. CT may detect an absence of blood flow to the liver or kidney, indicating severe injury. The main issue with these organs is to be sure they are in one piece and functioning.

The sensitivity of CT is only 68% for pancreatic injuries. This pancreas can be damaged when it is compressed against the spine, which may occur in a bicycle- or sports-related impact. CT can be used to spot active bleeding; the active extravasation of IV contrast is the hallmark, but it may be subtle.

In the pelvis, fractures and other bony injuries and free fluid are the biggest concerns. Pelvic fractures, which are generally easy to see on imaging, suggest that the body sustained a large amount of force. Free fluid in the pelvis can indicate a solid organ injury, a mesenteric injury, a bowel injury, or even a preexisting condition such as ascites.

Dr. Perron reported no conflicts of interest.