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CT neck (protocol)

The CT neck protocol serves as a radiological examination of the head and neck. This protocol is usually performed as a contrast study and might be acquired separately or combined with a CT chest or CT chest-abdomen-pelvis. On rare occasions, it will be performed as a non-contrast study. Dependi...

Parathyroid 4D CT

Parathyroid four-dimensional (4D) CT refers to multiphase computed tomography of the neck used to localize abnormal parathyroid glands (i.e., involved with adenoma, hyperplasia, or, rarely, carcinoma). The "4D" indicates that imaging is performed in multiple phases of contrast, with time being t...

Sequential CT image acquisition

Sequential CT scanning, also referred to as "scan-move-scan" or "step and shoot", was the conventional method of image acquisition in computed tomography before the advent of helical CT.  In sequential scanning, the patient is moved forward along the longitudinal axis of the CT scanner, pausing...

Schuller's view

Schuller's view is a oblique radiographic projection used to demonstrate the petrous temporal bone, internal auditory canal and bony labyrinth. It has an increasingly limited role in contemporary clinical practice because of the universal use of CT and MRI for imaging the temporal bone.  Patien...


Lymphoscintigraphy is a nuclear medicine technique to visualize regional lymphatic drainage, especially for mapping sentinel lymph nodes, from a site of radiopharmaceutical injection. Radiopharmaceutical Colloidal agents are used as these particles enter lymphatic channels and migrate to lymph...

Thyroid scintigraphy (Tc-99m)

Tc-99m pertechnetate thyroid scintigraphy (thyroid scan) is a functional nuclear medicine study used to assess the thyroid gland. The uptake of the pertechnetate anion - similar in chemical-physical characteristics to the iodide ion - in the thyroid parenchyma is mediated by the NIS (sodium-iodi...

Tc-99m pertechnetate

Tc-99m pertechnetate (Na+ 99mTc O4-) is one of the technetium radiopharmaceuticals used in imaging of thyroid, colon, bladder and stomach. Technetium (99mTc) has eight oxidation states 6, from -1 to +7; specifically, the oxidation state of technetium in the pertechnetate anion (99mTcO4-) is +7....

Comet tail artifact

The comet tail artifact is a grey scale ultrasound finding seen when small calcific / crystalline / highly reflective objects are interrogated and is believed to be a special form of reverberation artifact. It is similar to the color comet tail artifact and is seen in similar situations, althou...

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