The pulmonary perfusion scintigraphy records the distribution of pulmonary arterial blood flow. The most common indication for lung scintigraphy is the detection of pulmonary embolism. The most widely used radiopharmaceuticals are technetium-99m MAA (macroaggregates of albumin) or 99mTc-HAM. Other radiopharmaceuticals include sulphur colloid macroaggregated albumin, radioactive albumin microspheres and albumin labeled with I-131, or I-113m.
Perfusion imaging of the bronchopulmonary system is based on the principle of capillary blockade. The perfusion study is accomplished by injecting 40 to 160 MBq (1-4 mCi) of the radiopharmaceutical and during repeated deep inhalation. The aggregates are extracted during their first pass through the lung, thus imaging can begin immediately. Pulmonary perfusion scintigraphy is particularly useful in combination with gas ventilation scintigraphy and aerosol ventilation scintigraphy.

See also Inhalation Scintigraphy.

Contrast media injectors are part of the medical equipment used to deliver fluids in examinations such as CT, MRI, fluoroscopy and angiography. Many of these diagnostic imaging procedures include the administration of intravenous contrast agents to enhance the blood and perfusion in tissues.

Mainly there are two types of injector technology:
See also Single-Head Contrast Media Injector, Dual-Head CT Power Injector, Syringeless CT Power Injector.

The use of x-ray contrast agents in computed tomography (CT) began with a hand injection by the radiologist in the scan room. During its history, CT scanners have made great improvements in speed and image quality. Actual CT systems with multiple detectors allow scan times of a few seconds per body region. Some CT protocols require multiphase scans, where a body region is imaged with a single bolus of contrast in different blood flow phases. Automatic power (pressure) contrast media injectors are required to provide precise control of flow rate, volume and timing of injection. The use of a saline bolus following contrast administration reduces the volume of contrast required.

Most relevant topics for the use of a power injector in medical imaging procedures such as contrast enhanced computed tomography (CECT):
Must have basic injector control options:
Examples of other injector control options:

(CECT) Contrast agents are used during contrast enhanced computed (or computerized) tomography examinations to highlight specific tissues and parts of the body. Bones can be clearly seen on x-ray images, the visualization of some other organs and soft tissues is more difficult. Sufficient contrast is important in perceiving a difference in the density between areas of a CT image. The identification of a disease may be challenging due to very low contrast between pathological tissues (for example tumors, metastases and abscesses), normal organ structures and surrounding tissues.
Contrast agents are used in CT angiography (CTA) to delineate vessels, in multiphasic CT studies to provide dynamic information of blood supply (e.g., liver CT) and in CECT studies of various body parts to achieve opacification of tissue of interest (e.g., kidney CT) in relation to the background tissue. Contrast enhanced multi-detector row CT (MDCT) replaces several conventional diagnostic imaging methods such as intravenous urography, cholangiography, or catheter angiography, due to advanced CT studies with fast examination times, high contrast enhancement, perfusion measurement and multiplanar reformatting capabilities.
See also Contrast Media Injector, Single-Head CT Power Injector, Multi-Head Contrast Media Injector, Syringeless CT Power Injector, CT Power Injector.

A gas ventilation scintigraphy is a diagnostic imaging test of lung ventilation with radioactive noble gases during breathing maneuvers, e.g. with krypton (81mKr) or xenon (133Xe).
The radioactive gas is administered by a mask and requires a special delivery and trapping system (gas trap). The radioactivity in the lungs is measured with a gamma camera and is subsequently evaluated.
The use of krypton or xenon gases involves problems like the relatively short half-lives (about 15-30 seconds) and relatively high costs of xenon and krypton. The short half-life requires that the scan is performed directly after administration of the gas. In addition, the gaseous radiopharmaceutical is expelled from the body almost quantitatively within a few minutes of completing the study.
A ventilation scintigraphy combined with a pulmonary perfusion scintigraphy is highly sensitive for the detection of pulmonary embolism.
Radioactive noble gases are widely used as a ventilation agent to diagnose pulmonary embolism. However, 81mKr and 133Xe are rare and expensive, which limits their continuous availability. Tc99m-Technegas can be an alternative ventilation agent with the advantage of being less expensive and available daily.

See also Inhalation Scintigraphy.

Scintigraphic imaging of the lungs is a sensitive diagnostic imaging tool to detect certain kinds of pulmonary abnormalities in correlation with clinical data and chest radiographs. Pulmonary scintigraphy is particularly useful in diagnosing medical conditions such as pulmonary embolism, bronchial carcinoma and chronic obstructive pulmonary disease.
Lung scintigraphy can be performed with radioaerosols, gaseous radiopharmaceuticals and technetium-99m-labeled perfusion agents that are localized by temporary capillary blockade.

Different types of lung scintigraphy include:
The choice of the radioactive tracer varies and depends on the pulmonary function to be imaged. The radioactive tracer distribution within the lungs can be displayed on a computer screen via a gamma camera, a scanner or some other similarly suitable detector that records the radioactive disintegrations emitted by the patient. The images obtained present chromatic variations proportional to the regional radioactivity.