Chest Protocols

Spiral CT Evaluation for Traumatic Aortic Injury (TAI)

  1. All patients with clinically significant chest trauma for whom a contrasted CT of the abdomen and/or pelvis is requested by the trauma surgery or emergency room service should undergo CT scanning of the chest concurrently. This should be done with the protocol designed for detecting aortic injury.

  2. Patients with isolated chest trauma will undergo spiral CT examination at the behest of the clinician.

  3. CT will precede aortography in most cases. Only in specific circumstances ( e.g. in a patient with isolated chest trauma , an abnormal chest radiograph and marginal renal function) will aortography be performed without prior CT scanning.

  4. Scans will be initially interpreted by the resident on call:

    A.  If there is no mediastinal hemorrhage or direct findings of aortic or great vessel injury ( psuedoaneurysm or oter abnormal vessel contour or abrupt change in vessel diameter, intralumenal thrombus or intimal flap) the scan will be interpreted as negative for TAI. These patients will not undergo angiography without consultation between the Trauma Service attending and the interventional radiologist on call.

    B.  If there is mediastinal hemorrhage limited to the anterior mediastinum without direct contact with the aorta or supra-aortic vessels and there are no direct signs of vascular injury, the CT scan will be interpreted negative for TAI. Patients will not undergo angiography without consultation between the Trauma Service attending and the interventional radiotogist on call.

    C.  If there is mediastinal hemorrhage clearly centered on a vertebral body fracture without direct contact with the aorta or supra-aortic vessels and there are no direct signs of vascular injury, the CT scan will be reviewed by the interventional
    attending radiologist.  (Note: This differs from "B" because this is often a more difficult call). If the attending agrees with the interpretation, the study will be interpreted as negative for TAI. These patients will not undergo angiography without consultation between the Trauma Service attending and the interventional attending radiologist on call.

    D.  If there is mediastinal hemorrhage in contact with the aorta or supra-aortic vessels but no direct evidence of vascular injury, the patient should receive aortic angiography.

    E.  If there is mediastinal hemorrhage and direct evidence of aortic or supra- aortic vessel injury the patient should either
    receive angiography or proceed directly to surgery. If the patient is to proceed directly to surgery the scan must be viewed by an attending radiologist.

Spiral CT Evaluation of Possible PE

  1. CT for PE can be performed any day of the week. However, it should only be performed when a resident or staff radiologist can be in attendance to help correctly identify the region to be scanned and answer technologist's questions (See #5 below). In general  this will not be possible during those hours of the night and early morning when only a single radiology resident is present in house.

    The attendings listed in #4 are happy to the read the studies (including on the weekends) but do not plan on coming in after hours unless very special circumstances arise on call.

  2. CT for PE is most useful in Patients with intermediate probability VQ scans Patients with high probability scans prior to IVC filter placement (for confirmation of PE) As an initial study (rather than VQ scan) in patients with a large amount of parenchymal lung disease.
  3. CT for PE is likely to be suboptimal if: Patient is combative or otherwise prone to gross motion artifact  The patient can not hold his/her breath for at least 10 seconds   (Note: Patients on mechanical ventilation are fine as long as they receive neuromuscular blockers, e.g. Norcuron, prior to the scan).
  4. Scans may be reviewed by the resident on call, but all CT scans for PE must be interpreted by either Dr. M. Williamson, Dr. Locken, or Dr. Ketai within 24 hours after performed.

    A. Scans must be reviewed on the work station in addition to hard copy.

    B. If Drs. Williamson, Locken, or Ketai will not be available within 24 hours DO NOT DO THE SCAN! (Yes, it's okay to call us at home on the weekends)
  5. Regarding positioning of scan area:

    A.  Easy at the VA where the Rhino tube reigns, and can cover a large distance. Go from the the top of the highest diaphragm to the top of the aortic arch

        a. If the highest diaphragm is more than 2-3 cm above the other diaphragm, I would start a little lower.
        b. If you are not sure, use the lowest inferior pulmonary vein (usually the left) as a starting point. To find this you will need to do a preliminary non-contrast CT.

    B. Hard at the University, with the wimpy CT tube

        a. Same objectives as at the VA, but you may have trouble covering the entire area desired with one acquisition.
        b. If you can't cover the optimal area, at least try to cover the area of highest suspicion. Usually this is in the lower lobes.  Use the prior VQ (if done) or CXR to help you pick the area (e.g. include consolidation which could represent a pulmonary infarct).