The dimension of the ultrasound beam and the transducer array are the origin of the slice thickness artifact. This artifact is also called partial volume artifact or volume averaging artifact.

See also Validation.

If available, some graphic aids can be helpful to show image orientations.
1) A graphic icon of the labeled primary axes (A, L, H) with relative lengths given by direction sines and orientation as if viewed from the normal to the image plane can help orient the viewer, both to identify image plane orientation and to indicate possible in plane rotation.
2) Ingraphic prescription of obliques from other images, a sample original image with an overlaid line or set of lines indicating the intersection of the original and oblique image planes can help orient the viewer.


In all cases the scanning surface is assigned to the top of the image. The orientation of single oblique slices can be specified by rotating a slice in one of the basic orientations toward one of the other two basic orthogonal planes about an axis defined by the intersection of the 2 planes.

See also Histogram.

A partial volume artifact is caused by the size of the image voxel. The loss of resolution is caused by multiple features present in the image voxel. In ultrasound imaging that occurs when the slice thickness is wider than the scanned structure. This artifact is also called slice thickness artifact or volume averaging artifact.

See also Ultrasound Picture.

A voxel is a volume element (volumetric and pixel) representing a value in the three dimensional space, corresponding to a pixel for a given slice thickness. Voxels are frequently used in the visualization and analysis of medical data. The ultrasound pixel intensity is proportional to the signal intensity of the appropriate voxel.

See also Slice Thickness Artifact.

2D ultrasound imaging is a widely used technique in medical imaging that provides two-dimensional visual representations of internal structures. A handheld device known as a probe or transducer contains piezoelectric crystals that emit and receive ultrasound waves which penetrate tissues and bounce back as echoes. The echoes are detected and converted into electrical signals. These signals are processed and displayed on a monitor, creating a real-time 2D grayscale image, with different shades of gray representing various tissue densities. The brighter areas on the image correspond to structures that reflect more ultrasound waves, while darker areas represent structures that reflect fewer waves or are attenuated by intervening tissues. The 2D-mode (or B-mode) provides cross-sectional views of the scanned area, showing a single plane or slice of the scanned area at a time.

Key Features and Uses of 2D Ultrasound:

Comparison with 3D and 4D Ultrasound:
See also Ultrasound Technology, Sonographer, Ultrasound Elastography, Obstetric and Gynecologic Ultrasound.