Areas that absorb little or no amount of tracer appear as dark or "cold" spots. This could show a lack of blood supply to the bone or certain types of cancer. Areas of fast bone growth or repair absorb more tracer and show up as bright or "hot" spots in the pictures.
The scanner uses the information to make a picture of the bones. The areas where the radionuclide collects are called "hot spots." They may be a sign of conditions such as cancerous bone tumors and metastatic bone cancer. This is cancer that has spread from another site, such as the lungs, to the bones.
Annular tears are seen on MRI scans of the lumbar spine. They appear as tiny white dots in the back of the disk.
Scan A shows hot spots (dark areas) in both knees, a sign of arthritis, and a possible fracture in the second toe of the right foot. Otherwise, it shows typical bone metabolism. Scan B shows numerous bone hot spots, a result of cancer that has spread to multiple locations.
Image A, anterior bone scan, correlates to the the color scale (graph) above. Pixels start to change color from black/purple (low counts) to orange/red (high counts). Therefore, the positions of the image that displays yellow/red have the greatest amount of counts possibly representing some type of abnormality.
An abnormal scan will show "hot spots" and/or "cold spots" as compared to surrounding bone. Hot spots are areas where there is an increased collection of the radioactive material. Cold spots are areas that have taken up less of the radioactive material.
Using a bone scan when cancer is suspected can be particularly helpful because the scan can find both primary cancer—or, cancer that started in your bones—and bone metastases, which is cancer that has spread to the bones from another part of your body.
When inflammation is present, blood flow to that area increases in proportion to the inflammation. A radioactive marker is injected into a vein (through an IV), and the marker will travel to the area of inflammation. Time is allowed for the marker to reach the area of inflammation or high bone turn over.
During a bone scan, a tracer (a radioactive substance) is injected into your bloodstream. The tracer collects in the bone and settles in the areas where the bone is being repaired. The area that is affected by a stress fracture will appear darker on the bone scan that an uninjured area.
White spots on a brain MRI are not always a reason to worry. There are many possible causes, including vitamin deficiencies, infections, migraines, and strokes. Other risk factors for white spots include getting older, race/ethnicity, genetics, obesity, diabetes, hypertension, and high cholesterol.
However, with T2 imaging, the cerebrospinal fluid, which is the normal fluid in and around the brain and spinal cord, also appears bright white.
Bone has the highest density on CT scan (whitest in appearance.)
Bone tumors develop when cells within a bone divide uncontrollably, forming a lump or mass of abnormal tissue. Most bone tumors are benign (not cancerous). Benign tumors are usually not life-threatening and, in most cases, will not spread to other parts of the body.
What are Lytic Lesions? Also known as bone lesions or osteolytic lesions, lytic lesions are spots of bone damage that result from cancerous plasma cells building up in your bone marrow. Your bones can't break down and regrow (your doctor may call this remodel) as they should.
A T score of -1 to +1 is considered normal bone density. A T score of -1 to -2.5 indicates osteopenia (low bone density). A T score of -2.5 or lower is bone density low enough to be categorized as osteoporosis.
If your T-score is: 1 or higher, your bone is healthy. –1 to –2.5, you have osteopenia, a less severe form of low bone mineral density than osteoporosis. –2.5 or lower, you might have osteoporosis.
Triple-phase bone scans have high sensitivity for detecting osteomyelitis in non-violated bone, even in the early stages of infection. However, their specificity is lower when bone has been violated—for instance in trauma, malignancy or previous surgery.
The increased bone-making activity that the dark spots represent is the skeleton's response to the problem. For example, if there is a bone fracture, bone cells will very quickly begin to make new bone to try to repair it. That activity will appear as a dark spot on a bone scan.
A normal bone scan shows the radiotracer spread evenly among the bones, and no areas have too little or too much tracer. An abnormal bone scan shows hot spots or cold spots. Hot spots are areas of bone where the tracer has collected. Hot spots can be caused by bone cancer, arthritis, a bone infection or disease.
Cancerous tissue also shows up as white on a mammogram. Therefore it is sometimes hard to distinguish dense tissue from cancerous tissue. On an ultrasound cancerous tissue shows up black and dense tissue is still white, therefore cancers are easier to distinguish.
Patients may present with fever and skeletal symptoms and, in such cases, bone scintigraphy may be requested in the early search for a diagnosis. Recognition of the potential scintigraphic abnormalities that result from leukemic infiltration of bone and bone marrow will often facilitate an early diagnosis of leukemia.