Computed Axial Tomograph CAT Scan

Nurse Bob's MICU/CCU Survival Guide
Diagnostic Testing for Critical Care
Computed Axial Tomograph (CAT Scan)

I. Definition.
    A. A imaging method employing tomography.
    B. A three dimensional image of the inside of the body is generated from two dimensional xray slices of the body.

II. CT scanning of the head is typically used to detect:
    A. Bleeding, brain injury and skull fractures
    B. Bleeding due to a ruptured/leaking aneurysm in a patient with a sudden severe headache
    C. A blood clot or bleeding within the brain shortly after a patient exhibits symptoms of a stroke
    D. A stroke
    E. Brain tumors
    F. Enlarged brain cavities in patients with hydrocephalus
    G. Diseases/malformations of the skull
    H. Evaluate the extent of bone and soft tissue damage in patients with facial trauma, and planning surgical reconstruction
    I. Diagnose diseases of the temporal bone on the side of the skull, which may be causing hearing problems
    J. Determine whether inflammation or other changes are present in the paranasal sinuses
    K. Plan radiation therapy for cancer of the brain or other tissues
    L. Guide the passage of a needle used to obtain a tissue sample (biopsy) from the brain
    M. Assess aneurysms or arteriovenous malformations

III. CAT of Chest is used to detect.
    A. Acute and chronic changes in the lung parenchyma.
    B. Evaluation of chronic interstitial processes such as emphysema, pulmonary fibrosis.
    C. Detection of airspace disease (such as pneumonia) or cancer.
    D. Detecting pulmonary embolism (PE)
    E. Detecting aortic dissection.

IV. Cardiac
    A. Imaging of the coronary arteries (cardiac CT angiography).
    B. ECG is used to correlate the CT data with their corresponding phases of cardiac contraction.

V. Abdominal and pelvic
    A. Determine stage of cancer and to follow progress.
    B. It is also a useful test to investigate acute abdominal pain.
    C. renal stones, appendicitis, pancreatitis, diverticulitis, abdominal aortic aneurysm, and bowel obstruction.

VI. Extremities
    A. CT used to image complex fractures