Chapter 2 – Specialized Imaging Techniques: Vocabulary Flashcards

Vocabulary flashcards covering the key terms and concepts introduced in Chapter 2, Specialized Imaging Techniques.

Imaging features

when Radiologist interpret images, they use common terminology

Location, size, density, structure, shape, demarcation, perfusion, integration

Terms used to describe imaging features

Mammography

Designed x-ray tubes to provide high-quality images of the breast

Screening and diagnostic exams

What type of exams does mammography do?

Ionizing radiation xray attenuation of breast tissue

Image creation in mammo

Same as used for general xray

Imaging descriptors in mammo

Digital plate or analog system

Image receptor in mammo

Ultrasound

Non-invasive modality using high-frequency sound waves generated and received by a transducer; low cost, widely available, and able to differentiate cystic, solid, or complex tissue.

Low cost availability ability to differentiate cystic solid and complex tissues

Ultrasound advantages

Transducer production of multi frequency sound waves

Image creation in ultrasound

Transducer receiving echoed signal

Image receptor in ultrasound

Anechoic hyperechoic isoechoic

Imaging descriptors in ultrasound

Anechoic

Echo-free area that appears dark on an ultrasound image.

Hyperechoic

Area with increased echo intensity that appears lighter than surrounding tissue on ultrasound.

Hypoechoic

Area with decreased echo intensity that appears darker than adjacent tissue on ultrasound.

Isoechoic

Two structures that display the same echogenicity (same shade) on ultrasound.

Computed tomography (CT)

Radiation-based modality that produces cross-sectional images with the highest contrast resolution and very efficient scan times.

CT number (Hounsfield number)

Numeric value reflecting a tissue’s attenuation relative to water (0); bone ≈ +1000 (white), air ≈ –1000 (black).

Multiplanar reconstruction

Refers to a method by which images acquired in the axial plane may also be reconstructed in the coronal or sagittal plane

Prepatient and postpatient

Two collimator for ct

At the xray tube shapes and limits the beam

Prepatient

At the detectors

Postpatient

Conventional images

Sectional thickness of 5-10 mm

High resolution images

require 1.5 - 2mm in thickness

Ct

Can detect tissue density differences as low as 1% or less aiding differential diagnosis of pathologies compared to conventional radiography that have at least a 5% difference

Ct

Which modality has the highest contrast resolution?

Image receptor ct

Collimated x ray beam attenuation detection

Maximum intensity projection (MIP)

Enhancing brightness intensities

Minimum intensity projection (MinIP)

Enhancing lowest intensity colonoscopy

Virtual reality (VR)

Demonstrate internal structures for virtual telescopic or colonoscopy post processing for CT

Multiplanar reconstruction (MPR)

Technique that reprocesses axial CT data to create coronal and sagittal images.

Multislice CT

CT system with a dual-focus x-ray tube and multi-element detector array that can acquire 8–320 images per rotation.

Magnetic resonance imaging (MRI)

Modality that uses a strong static magnetic field and radiofrequency (RF) pulses to alter hydrogen atom energy states, producing images with excellent soft-tissue resolution.

MRI

What modality has images of the cns spine and many Musculoskeletal conditions

Fat suppression

differentiates fat from contrast material to highlight vascular structures

Diffusion-weighted

High signal intensity, bright, where a random movement or of water is restricted stroke liver lesions

Susceptibility-weighted

sensitive to substances that alter magnetic susceptibility; hemorrhage or calcium appear dark (low signal).

Nuclear medicine (NM)

The patient will ingest or be injected with a radio pharmaceutical that emits radiation.

Nm

allows for a visualization of physiologic processes and detects some disease diseases early

Single positron emission computed tomography

Spect

Transverse, coronal, or sagittal plane

For spect images can be

Image creation for NM and SPECT

Radiopharmaceutical that emits Gamma radiation

Image receptor for NM

Gamma camera that detects gamma radiation emitted from patient

Image receptor for SPECT

Rotating gamma camera for multiplanar gamma radiation collection

Hot spot

Increased uptake directly proportional to the emission of gamma radiation NM or SPECT images.

Cold spot

Reflection of decreased uptake directly proportional to the emission of gamma radiationon NM or SPECT images.

Positron emission tomography (PET)

Uses a radionuclide tracer similar to a naturally occurring substance in the body, such as carbon, oxygen, nitrogen or glucose

PET

Useful in oncology, cardiology, and neurology

Fusion imaging

Increases the accuracy of a diagnosis combines anatomic images with metabolic function

Image creation for PET

Radiopharmaceutical that emits a positron through the collection following in inhalation two gamma rays are created

Image receptor for PET

Two opposite gamma cameras that detect gamma radiation simultaneously emitted from patient

Image receptor of fusion imaging

Two imaging receptors of modality employed

Integrated imaging

Software create images, overlay modality image data set