Medical Imaging Terminology PDF

1 Terminology 1-Definition of Anatomical terminology : is a form of scientific terminology used to describe parts of the human body accurately and universally Patient aspect Anterior aspect: that seen when viewing the patient from the front. Posterior (dorsal) aspect: that seen when viewing the...

1 Terminology 1-Definition of Anatomical terminology : is a form of scientific terminology used to describe parts of the human body accurately and universally Patient aspect Anterior aspect: that seen when viewing the patient from the front. Posterior (dorsal) aspect: that seen when viewing the patient from the back. Lateral aspect: refers to any view of the patient from the side.The side of the head would therefore be the lateral aspect of the cranium. Medial aspect: refers to the side of a body part closest to the midline, e.g. the inner side of a limb is the medial aspect of that limb. 1 Positioning terminology 2- Definition of Planes of the body : Three planes of the body are used extensively for descriptions of positioning both in plain-film imaging and in cross-sectional imaging techniques. The planes described are mutually at right angles to each other: Median sagittal plane: divides the body into right and left halves. Any plane that is parallel to this but divides the body into unequal right and left portions is known simply as a sagittal plane or parasagittal plane. Coronal plane: divides the body into an anterior part and a posterior part. Transverse or axial plane: divides the body into a superior part and an inferior part. 2 1 Terminology Positioning terminology (contd) This section describes how the patient is positioned for the various radiographic projections described in this text: Definition of Erect Position: the projection is taken with the patient sitting or standing. In the erect position, the patient may be standing or sitting: with the posterior aspect against the cassette; or with the anterior aspect against the cassette; or with the right or left side against the cassette. Definition of Decubitus position: the patient is lying down. In the decubitus position, the patient may be lying in any of the following positions: Supine (dorsal decubitus): lying on the back. Prone (ventral decubitus): lying face-down. Lateral decubitus: lying on the side. Right lateral decubitus – lying on the right side. Left lateral decubitus – lying on the left side. Semi-recumbent: reclining, part way between supine and sitting erect, with the posterior aspect of the trunk against the cassette. Supine: the median sagittal plane is at right-angles to the table and the Erect: standing with the anterior aspect of the thorax against a coronal plane is parallel to the table vertical Bucky Prone: the median sagittal plane is at right-angles to the table and the Left lateral decubitus: the median sagittal plane is parallel to the table coronal plane is parallel to the table and the co ronal plane is perpendicular to the table 3 Positioning terminology Semi-recumbent, with posterior aspect of the thorax against the Right lateral erec t: standing with the right side against a cassette and median sagittal plane perpendicular to the cassette vertical Bu cky When describing positioning for upper-limb projections, the patient will often be ‘seated by the table. The photograph below shows the correct position to be used for upper-limb radiography, The patient’s legs will not be under the table, therefore avoiding exposure of the gonads to any primary radiation not attenuated by the cassette or the table. Correct patient position for upper-limb radiography with the patient seated 4 Positioning terminology (contd) Terminology used to describe the limb position Positioning for limb radiography may include: a description of the aspect of the limb in contact with the cassette; the direction of rotation of the limb in relation to the anatomical position, e.g. medial (internal) rotation towards the midline, or lateral (external) rotation away from the midline; the final angle to the cassette of a line joining two imaginary landmarks; the movements, and degree of movement, of the various joints concerned. Extension: when the angle of the joint increases. Flexion: when the angle of the joint decreases. Abduction: refers to a movement away from the midline. Adduction: refers to a movement towards the midline. Rotation: movement of the body part around its own axis, e.g. medial (internal) rotation towards the midline, or lateral (external) rotation away from the midline. Pronation: movement of the hand and forearm in which the palm is moved from facing anteriorly (as per anatomical position) to posteriorly. Supination is the reverse of this. Other movement terms applied to specific body parts are described in the diagrams. 5 Terminology 1 Projection terminology Definition of Projection terminology: A projection is described by the direction of the central ray relative to aspects and planes of the body. Definition of Antero-posterior: The central ray is incident on the anterior aspect, passes along or parallel to the median sagittal plane, and emerges from the posterior aspect of the body. Definition of Postero-anterior: The central ray is incident on the posterior aspect, passes along or parallel to the median sagittal plane, and emerges from the anterior aspect of the body. Definition of Lateral projection: The central ray passes from one side of the body to the other along a coronal and transverse plane. The projection is called a right lateral if the central ray enters the body on the left side and passes through to the image receptor positioned on the right side. A left lateral is achieved if the central ray enters the body on the right side and passes through to the image receptor, which will be positioned parallel to the median sagittal plane on the left side of the body. 6 Beam angulation Oblique Definition of Anterior oblique: The central ray enters the posterior aspect, passes along a transverse plane at some angle to the median sagittal plane, and emerges from the anterior aspect. Definition of Posterior oblique: The central ray enters the anterior aspect, passes along a transverse plane at some angle to the median sagittal plane, and emerges from the posterior aspect. 7 Oblique using beam angulation When the median sagittal plane is at right-angles to the cassette, right and left anterior or posterior oblique projections may be obtained by angling the central ray to the median sagittal plane. Example of the position for a right posterior oblique Lateral oblique The central ray enters one lateral aspect, passes along a transverse plane at an angle to the coronal plane, and emerges from the opposite lateral aspect. Example of the position for a right lateral oblique 8