Question

Using your knowledge of the sensitivity and specificity for different imaging modalities, provide an estimate on the approximate time since onset ( talk about CT scans and MRI and Pet scan)

Answer 1

CT scan:

Computed tomography involves many combinations of X-ray which are computer-processed from which the measurements taken from different angles to produce cross-sectional images of the subject. The approximate time for the procedure form the onset usually takes between 15 and 30 minutes and usually varies depends on the type, location and the contrast material

MRI:

Magnetic resonance imaging uses combinations of magnetic fields, magnetic field gradients, and radio waves to image the anatomy and the physiological processes of the organs/organ system. Time taken for MRI vary between10 minutes to over an hour to complete greatly depend on the location, organ and type of MRI being analyzed.  

PET scan:

Positron emission tomography used to analyze the metabolic process using a radio active material that helps to reveal functioning of tissues and organs. It is effective that it can diagnose the disease before that can be detected by other imaging tests. Typically a pet scan takes about 2–3 hours. An incubation time of 1 hour to enable drug to be absorbed and imaging time of 30-60 mins is needed.