PROCEDURES AND TECHNIQUES

RADIOLOGY AND DIAGNOSTIC IMAGING

Medical University in Lublin Magdalena Jarząbek

Radiology & Diagnostic Imaging Overview

►X-Rays High-energy electromagnetic waves

Travel in straight lines

Shorter wave length than visible light

Able to penetrate solid materials of varying densities (penetration, absorpsion,reflection)

Capable of exposing a photographic plate (x-ray film – PC image) ►Much the same way as a camera exposes film

►X-Rays

Used to visualize internal organs and structures of body

Provide valuable means for verifying presence of illness or disease

First line examination – screening - not the final diagnosis

Radiology & Diagnostic Imaging Overview (continued)

►Defined

A painless, noninvasive diagnostic x-ray

procedure using ionizing radiation that produces a cross-sectional image of the body

Computed Axial Tomography (CT, CAT)

Computed Axial Tomography (continued)

Perfusion (CT, MRI)

► In physiology, perfusion is the process of nutritive delivery of arterial blood to a capillary bed in the biological tissue.

►With the presence of contrast (iodinated or gadolinium)

►Various mathematical models can be used to process the raw temporal data to ascertain quantitative information such as rate of cerebral blood flow (CBF) following an ischemic stroke or aneurysmal subarachnoid hemorrhage.

Magnetic Resonance Imaging (MRI)

►Defined

A noninvasive scanning procedure that provides visualization of fluid and soft tissue without the use of radiation but using magnetic field and radio waves attributes

Perfusion MRI

Diffusion MRI ► Diffusion describes the spread of particles through random

motion from regions of higher concentration to regions of lower concentration.

► Diffusion weighted imaging (DWI) - each image voxel (three dimensional pixel) has an image intensity that reflects a single best measurement of the rate of water diffusion at that location. This measurement is more sensitive to early changes after a stroke or tumour spread than more traditional MRI measurements .

► Diffusion tensor imaging (DTI) is important when a tissue - such as the neural axons of white matter in the brain or muscle fibers in the heart - has an internal fibrous

structure analogous to the anisotropy of some crystals.

Diffusion MRI

Haemangioma in the liver

Tractography

Angiography

►Defined

A series of x-ray films allowing visualization of internal structures after the introduction of a radiopaque substance

Cerebral Angiography

►Defined

Injection of a radiopaque contrast medium into an arterial blood vessel (carotid, femoral, or brachial) to make visualization of the cerebral vascular system via x-ray exposure