Advanced Imaging Lecture Notes

Flashcards covering the fundamentals, technical procedures, and clinical applications of CT, MRI, and Diagnostic Ultrasound as discussed in the Advanced Imaging lecture.

Godfrey Hounsfield

The individual who invented Computed Tomography (CT) in 1972 and received a Nobel prize in 1979.

CT (Computed Tomography)

An imaging modality that creates cross-sectional axial slices using multiple x-rays (ionizing radiation) from different angles.

Scout Image

A two-dimensional digital radiograph produced by a CT scanner used to localize structures to be scanned.

Volume Averaging

A loss of resolution in CT images that occurs when tissues lie proximate or over each other, such as at a bone and tendon interface.

Windowing

A process in CT imaging used to reduce the range of radiodensities displayed to focus on a particular tissue.

CT Myelogram

An imaging procedure involving the injection of contrast material into the spinal fluid; it excels in evaluation of spinal stenosis.

Cone Beam CT

A form of CT involving a single volume of data that allows for shorter scanning time and less radiation, often used in dental practice.

Poland's Syndrome

A disorder in which individuals are born with missing or underdeveloped muscles on one side of the body, often affecting the chest, shoulder, arm, and hand.

T1-Weighted MRI

An imaging sequence that captures early signal decay and longitudinal remagnetization, providing good anatomic detail of tissues like fat.

T2-Weighted MRI

An imaging sequence that captures late-stage signal decay and transverse relaxation, useful for imaging structures like water and detecting inflammation.

Spin-echo (SE)

Standard MRI sequences used specifically for T1 and T2 imaging.

Gradient-echo (GRE) sequences

MRI sequences characterized by fast image acquisition and high resolution, producing high contrast between fluid and cartilage.

MR Arthrography

An MRI technique where Gadolinium in iodine is injected into a joint to visualize small defects in the capsule, ligaments, or labra.

MR Myelography

A high-resolution MRI study of the spinal canal and subarachnoid space using strong T2 weighting without contrast material.

Rehabilitative Ultrasound Imaging (RUSI)

A procedure used by physical therapists to evaluate muscle and soft tissue morphology and function during exercise to improve neuromuscular function.

Pulser

An ultrasound equipment component that produces waves of electrical energy in the frequency range of $2$ to $15\,MHz$.

Transducer

A device that converts electrical waves into sound energy and converts the reflected waves back into electrical energy.

Echogenicity

The degree to which tissues reflect sound waves in ultrasound imaging.

Acoustic Impedance

The difference in resistance between two tissue types at an interface, where larger differences result in more ultrasound reflection.

Doppler Ultrasound

A method based on the Doppler principle used to measure the velocity and direction of blood flow in an artery or vein.

Longitudinal Sonogram

An ultrasound scan where the transducer is applied along a tendon, resulting in a sagittal slice image of the structure.

Transverse Sonogram

An ultrasound scan where the transducer is applied across a tendon, resulting in an axial image of the structure.

Hyperechoic

Structures that reflect more energy than surrounding tissues, producing bright images; characteristic of normal tendons and ligaments.

Hypoechoic

Structures that reflect less energy than surrounding tissues, producing dark images; characteristic of muscle or bursa.

Anechoic

Structures that do not reflect energy and appear black on ultrasound, such as subcortical bone or cysts.