Nuclear imaging provides unique diagnostic and correlative information. Even though we do not image fine anatomical detail demonstrated so well by ultrasound, CT, and MRI, we can identify a variety of morphological abnormalities, sometimes more definitively than those anatomical modalities. Then, through a series of complex electronics, dots are displayed on a TV screen . The position and intensity of these dots correspond to the characteristics of the original photons coming from the patient. The dot pattern thus created gives an image representation of the distribution of radioactive material within the patient .
Abnormal patterns indicate disease and reflect underlying pathophysiology.
One of the most common uses for nuclear medicine is for the investigation of liver disease. Much information about the liver can be ascertained by injecting different types of physiologically active molecules labeled with radioisotopes. The normal liver is quite pliable and changes shape from deep inspiration to expiration as well as from upright to supine position. In fact, the lack of change in shape of the liver from one position to the other may be used as a test for diffuse disease, which may reduce pliability of the organ. Patients with chronic obstructive pulmonary disease are often referred for liver scans because of suspected hepatomegaly.