'Image' p14 Searchterm 'Image' found in 4 terms [ • ] and 115 definitions [• ]Result Pages : •
A bone scan or bone scintigraphy is used to in evaluate diseases of the skeletal system. Scintigraphic whole body bone imaging is a highly sensitive method to show changes in bone metabolism. Increased metabolic activity is seen as a hot spot. The study requires the injection of a 99mTc-labeled radiopharmaceutical (most commonly methylene diphosphonate (MDP), hydroxymethylene diphosphonate (HMDP) or hydroxyethylene diphosphonate (HDP)). The activity administered for bone scanning is around 500 MBq (300-1100 MBq, 8-30 mCi), depending on age and weight of the patient. After 2-5 hours, the emitted gamma rays are detected by gamma cameras. The produced planar images include anterior and posterior views of the skeleton. Multiphase bone scintigraphy is used to differentiate a bone process from tissue pathology. In some cases additional SPECT imaging is helpful to better characterize the presence, location and extent of disease. • View NEWS results for 'Bone Scan' (1). •
CAT/CT guided biopsies and other minimally invasive interventions are well established medical procedures. Since the beginning of computed tomography, conventional CAT/CT imaging studies has been used to guide an interventional procedure such as a tissue biopsy of a suspected tumor or metastases. Advanced interventional CT scanners provide fluoroscopic techniques allowing additionally the guidance of minimally invasive surgery or micro-therapy. Fluoro CT allows the continuous monitoring of the needle trajectory or inserted surgical instrument. A wide gantry opening, external tilting laser for needle guidance and special software ease the intervention. CT images are also used to plan radiotherapy cancer treatment and determine how the disease is responding to the treatment. Further Reading: Basics:
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(Computed tomography number) The CT number is a selectable scan factor based on the Hounsfield scale. Each elemental region of the CT image (pixel) is expressed in terms of Hounsfield units (HU) corresponding to the x-ray attenuation (or tissue density). CT numbers are displayed as gray-scale pixels on the viewing monitor. White represents pixels with higher CT numbers (bone). Varying shades of gray are assigned to intermediate CT numbers e.g., soft tissues, fluid and fat. Black represents regions with lower CT numbers like lungs and air-filled organs. • The cerebral blood pool can be imaged with single photon emission computed tomography (SPECT) and positron emission computer tomography (PET) techniques. The used radiopharmaceuticals are technetium-99m labeled red blood cells (RCBs) for SPECT and O-15 labeled water for PET imaging. Measured can be cerebral blood volume, brain perfusion and cerebral metabolism. See Cerebral Metabolic Imaging, Fluorodeoxyglucose, Regional Cerebral Blood Flow, Coincidence Detection, Annihilation Coincidence Detection and Cyclotron. • Cerebral metabolic imaging can be accomplished with positron emission computer tomography (PET), magnetic resonance spectroscopy, and functional magnetic resonance imaging. PET uses positron-emitting radioisotopes of elements with short half-live such as fluorine-18, oxygen-15, nitrogen-13, and carbon-11 as tracers to image and to measure the cerebral metabolism. Result Pages : |