A wide range of software techniques and advanced computer systems are developed that enable creation of three-dimensional images. Spiral CT allows the acquisition of CT data that is perfectly suited to 3D reconstruction. Advanced CT scanners image entire anatomic regions like the lungs in one breath hold and acquire a volume of data with the patient anatomy all in one position. This volume data is reconstructed to provide 3 dimensional pictures of for example complex blood vessels like the renal arteries or aorta. 3D reconstructions allow surgeons to visualize complex fractures in three dimensions and can help them plan reconstructive surgery.

A computed tomography (CT) of the abdomen images the region from the thoracic diaphragm to the pelvic groin. The computed tomography technique uses x-rays to differentiate tissues by their different radiation absorption rates.
Oral contrast material can be given to opacify the bowel before scanning. An i.v. injection of a contrast agent (x-ray dye) improves the visualization of organs like liver, spleen, pancreas and kidneys and provides additional information about the blood supply.
Spiral- or helical CT, including improvements in detector technology support faster image acquisition with higher quality. Advanced CT systems can usually obtain a CT scan of the whole abdomen during a single breath hold. This speed increases the detection of small lesions (caused by differences in breathing on consecutive scans) and is beneficial especially in pediatric, elderly or critically-ill patients.
Changes in patient weight require variations in x-ray tube potential to maintain constant detector energy fluence. An increased x-ray tube potential improves the contrast to noise resolution (CNR).

An abdominal CT is typically used to help diagnose the cause of abdominal pain and diseases such as:
Other indications for CT scanning of the abdomen/pelvis include planning radiation treatments, guide biopsies and other minimally invasive procedures. Advanced techniques include for example 3D CT angiography, multiphasic contrast-enhanced imaging, virtual cystoscopy, virtual colonoscopy, CT urography and CT densitometry.

See also Contrast Enhanced Computed Tomography.

The aerosol method uses technetium-labeled DTPA crushed by an atomizer into small particles. This aerosol inhales the patient during the aerosol ventilation scintigraphy to study airways disease.

Air KERMA (Kinetic Energy Released per unit MAss of air) measures the amount of radiation energy in air, unit is J/kg. This include the initial kinetic energy of the primary ionizing particles such as photoelectrons, Compton electrons, positron//negatron pairs from photon radiation, and scattered nuclei from fast neutrons, when for example air is irradiated by an x-ray beam. J/kg (gray) is also the unit of the radiation quantity 'Absorbed Dose'.

An anion is a negative charged ion; the atom has more electrons than protons. Anions are attracted from the positively charged anode. This is a basic part for producing radiation in the x-ray tube.