Lymphoscintigraphy maps lymphatic flow and sentinel nodes using injected radiocolloids for surgical planning and lymphedema assessment.
Dynamic and static imaging with planar or SPECT CT localizes sentinel nodes and evaluates lymphatic obstruction.
Sentinel lymph node mapping in oncology and evaluation of lymphedema.
Spatial resolution limited. Combined modalities improve localization for surgery.
PET images physiologic and metabolic processes using radiotracers such as FDG and detects areas of altered metabolism with high sensitivity.
Radiotracer selection uptake time and attenuation correction are critical. PET is often combined with CT or MRI for anatomic localization.
Oncology staging and response assessment infection and inflammation imaging and neurologic metabolic studies.
Radiation exposure from radiotracers and CT component. False positives from inflammatory uptake require clinical correlation.
SPECT acquires gamma emissions from radiotracers to reconstruct three dimensional functional images often combined with CT for localization.
Collimator choice acquisition orbit and reconstruction parameters influence resolution and sensitivity.
Cardiac perfusion imaging bone scans infection imaging and certain neurologic studies.
Lower spatial resolution than PET. Radiotracer selection and timing affect diagnostic yield.
