IP3 Key Terms

Aneurysm

A localised, blood-filled balloon-like bulge in the wall of a blood vessel.

Antecubital Fossa

The triangular cavity of the elbow, often used for venipuncture.

Arterial Stenosis

The narrowing or constriction of an artery, usually due to atherosclerosis.

Arteriovenous Malformation (AVM)

An abnormal tangle of blood vessels connecting arteries and veins, which can disrupt normal blood flow.

Atelectasis

A condition in which one or more areas of the lung collapse or do not inflate properly.

Axial

A cross-sectional imaging plane, typically parallel to the ground when the patient is supine.

Barium Sulphate Solution

A positive oral or rectal contrast medium used in CT to distend the bowel and demonstrate the intestinal lumen. Not used in suspected bowel perforation.

Bolus Tracking

A CT angiography technique where consecutive axial slices are performed at a region of interest while injecting contrast. The scan automatically begins when the contrast reaches a set Hounsfield Unit (HU) threshold in the target vessel.

Brain Bleeds

Hemorrhage within the brain, a common reason for CT Brain scans.

Bronchiectasis

Abnormal widening of the bronchi or their branches, increasing the risk of infection.

Cannula

A thin tube inserted into a vein or body cavity to administer fluids or withdraw samples. For angiography, 16-20 gauge is preferred.

Carina

The ridge at the base of the trachea that separates the openings of the right and left main bronchi. Used as a reference point for CTPA monitoring slices.

Cerebrovascular Accident (CVA) / Stroke

A sudden interruption in the blood supply of the brain, caused by either a blockage (thrombus) or a bleed.

Choledocholithiasis

The presence of gallstones within the bile ducts.

Cholesteatoma

An abnormal, non-cancerous skin growth that can develop in the middle section of the ear, often indicated for contrast CT IAMs.

Claudication

Pain, aching, or cramping in the leg muscles that occurs with exercise and is relieved by rest, typically caused by peripheral artery disease.

Cognitive Disorders

Mental health disorders affecting cognitive abilities like learning, memory, perception, and problem-solving, severely impairing normal function without treatment (e.g., dementia, Alzheimer's).

Contrast Extravasation

The leakage of injected contrast media from a blood vessel into the surrounding soft tissue.

Coronal

An imaging plane that divides the body into anterior (front) and posterior (back) sections.

CT Angiography (CTA)

A CT technique that allows visualisation of blood vessels using iodinated contrast, indicated for various vascular pathologies.

CT Arthrogram

A diagnostic test examining the inside of a joint, involving the injection of iodinated contrast into the joint space for enhanced imaging, typically with a bone window.

CT Cholangiogram

A high-resolution imaging technique of the biliary tree performed after intravenous administration of Billycan contrast, useful for delineating anatomy and identifying leaks/gallstones.

CT COW (Circle of Willis)

CT angiography of the circle of Willis, used to visualise intracranial arteries and identify vascular abnormalities or bleeding.

CT Urography (CT IVP)

A CT protocol largely replacing traditional IVP, providing both anatomical and functional information of the urinary tract, often using a split bolus technique.

CTPA (CT Pulmonary Angiography)

A CT scan performed to diagnose pulmonary embolism by visualising the pulmonary arteries.

Dementia

A brain disorder affecting communication and performance of daily activities. Alzheimer's is a form of dementia.

Dermatomes

Areas of skin primarily supplied by a single spinal nerve, useful in correlating spinal nerve compression with radiating pain.

Display Field of View (DFOV)

The specific area of the scanned anatomy displayed on the image.

Dyspnea

Shortness of breath or difficulty breathing, a common symptom for CT Chest scans.

EAM (External Auditory Meatus)

The ear canal, used as a reference point for patient positioning.

eGFR (Estimated Glomerular Filtration Rate)

A measure of kidney function, important for assessing contrast safety.

Embolus

A blood clot, air bubble, fat globule, or other foreign material that travels through the bloodstream and can cause a blockage.

Gastrografin

A water-soluble oral contrast medium that also has a laxative effect. Used as an alternative to barium.

GCS (Glasgow Coma Scale)

A neurological scale used to assess the conscious state of a person.

Hounsfield Units (HU)

A quantitative scale used in CT scanning to describe radiodensity. Different tissues and contrast media have characteristic HU values.

HRCT Chest (High Resolution CT Chest)

A CT technique using thin-sliced chest images reformatted with a high spatial frequency reconstruction algorithm, ideal for identifying small changes in lung tissue.

IAMs (Internal Auditory Meatus)

The canal within the temporal bone that transmits nerves and blood vessels to the inner ear. Scanned for conditions like acoustic neuroma or hearing loss.

Inferior Orbitomeatal Line (IOML)

An imaginary line extending from the inferior orbital rim to the external auditory meatus, often used for gantry angulation in head CTs.

Ischial Tuberosity

A bony prominence on the ischium, part of the pelvis, used as an anatomical landmark.

Jefferson's Burst Fracture

A classic fracture of the C1 (atlas) vertebra, typically involving two anterior and two posterior ring fractures, indicating an unstable injury.

Lobar Pulmonary Embolism

A pulmonary embolism located in a lobar artery, which supplies a lobe of the lung.

Mastoiditis

Inflammation of the mastoid process, a common reason for contrast CT IAMs.

MIPs (Maximum Intensity Projections)

A 3D post-processing technique that displays the highest intensity pixels along a ray, useful for visualising vessels and enhancing contrast.

Multiphasic Imaging

A CT scanning technique involving multiple acquisitions at different time points after contrast administration (e.g., non-contrast, arterial, portal venous, delayed phases).

Nephrolithiasis

The presence of kidney stones (renal calculi).

Nerve Root Block/Injection

An interventional CT procedure involving the injection of steroid pain relief near a nerve root to alleviate pain, often guided by soft tissue window imaging.

Neurological Disorders

Diseases affecting the brain and nervous systems, such as Alzheimer's, epilepsy, multiple sclerosis, and Parkinson's disease.

Oral Contrast

Liquid contrast material (e.g., water, barium, gastrografin) taken by mouth to distend and visualise the gastrointestinal tract.

Osteosclerosis

Increased density of bone, a reason for non-contrast CT IAMs.

Patella Tracking CT

A CT scan performed to assess patella instability, dislocations, and pain, often involving multiple knee flexion angles.

PICC (Peripherally Inserted Central Catheter)

A central venous catheter inserted into a peripheral vein, suitable for power injection if compatible.

Pituitary Fossa

The depression in the sphenoid bone where the pituitary gland is located.

Pneumothorax

The presence of air or gas in the space between the lung and the chest wall, causing lung collapse. A risk during lung biopsies.

Portal Venous Phase

A phase of contrast enhancement in multiphasic CT where contrast is visible in the portal venous system, typically around 70 seconds post-injection for abdominal scans.

Pressure Injector

A device used in CT to deliver precise flow rates and volumes of contrast consistently, often allowing for rapid injection without the radiographer in the room.

Priming

The process of filling the tubing and syringes of a pressure injector with saline and contrast to remove air bubbles before injection.

Radiculopathy

A condition in which a nerve root in the spine is compressed or pinched, causing symptoms like pain, weakness, and tingling sensations along a dermatome.

Reconstruction Series/Recons

The initial set of thin, overlapping slices obtained during the helical CT scan.

Reformats

Thicker slices created from the reconstructed series in different planes (axial, coronal, sagittal) or 3D visualisations.

Region of Interest (ROI)

A selected area on an image where Hounsfield Units are measured, often used in bolus tracking.

Renal Calculi

Kidney stones.

Reversible Cerebral Vasoconstriction Syndrome (RCVS)

A group of conditions characterised by thunderclap headaches and reversible vasoconstriction of cerebral arteries, indicated for CTA COW.

Saddle Pulmonary Embolism

A large pulmonary embolism that lodges at the bifurcation of the main pulmonary arteries, extending into both left and right pulmonary arteries; a medical emergency.

Sagittal

An imaging plane that divides the body into right and left sections.

Saline Bolus

A rapid injection of saline, often following contrast to push the contrast through the vasculature.

Scaphoid Fracture

A fracture of the scaphoid bone in the wrist, important to diagnose due to the risk of avascular necrosis.

SCD (Superior Canal Dehiscence Syndrome)

A rare inner ear condition caused by thinning or absence of part of the temporal bone overlying the superior semicircular canal, leading to hearing and balance symptoms.

Scout

A low-dose planning image (AP and/or lateral) performed prior to the helical scan to define the scan length and area of interest.

Serum Creatinine

A blood test measuring kidney function, essential before administering iodinated contrast.

Sol (Space Occupying Lesion)

A general term for any abnormal mass or growth within the body, such as a tumor.

Sphenoid Sinus

An air-filled cavity located within the sphenoid bone, part of the paranasal sinuses.

Split Bolus Technique

An injection method in CT Urography where contrast is administered in two separate boluses with a delay, aiming to image multiple phases simultaneously and reduce radiation dose.

Sternal Notch

A palpable landmark at the superior aspect of the manubrium, often used as a start reference point for chest scans.

Subarachnoid Hemorrhage

Bleeding into the subarachnoid space, often caused by ruptured intracranial aneurysms, a key indication for CTA COW.

Superior Mesenteric Artery (SMA)

A major artery supplying blood to the small intestine and parts of the large intestine.

Supine

Lying on the back with the face upwards.

Symphysis Pubis

The cartilaginous joint uniting the two pubic bones, a key landmark in pelvic imaging.

Thrombus

A blood clot that forms in a blood vessel and remains at the site of its formation.

TIA (Transient Ischemic Attack)

A 'mini-stroke' caused by a temporary blood clot that does not cause lasting damage.

Tinnitus

Ringing or buzzing in the ears, a symptom that may lead to a contrast CT IAMs.

Trauma

Physical injury, a very common referral reason for various CT scans (brain, chest, abdomen, extremities).

Urolithiasis

The presence of calculi (stones) anywhere along the course of the urinary tracts (kidneys, ureters, or bladder).

Vasculitis

Inflammation of the blood vessels, which can affect various organs and systems, including the central nervous system.

Vertex

The highest point of the skull.

Vertigo

A sensation of spinning or dizziness, which may lead to a contrast CT IAMs.

Window Level (WL)

The central Hounsfield Unit (HU) value of the CT image window, determining the brightness.

Window Width (WW)

The range of Hounsfield Units (HU) displayed on the CT image, determining the contrast. Different tissues (e.g., bone, soft tissue, lung, angiography) require different window settings.

Xiphisternum/Xiphoid Process

The small cartilaginous process at the bottom of the sternum, used as an anatomical landmark.

Zygomatic Arch

The arch of bone extending from the cheekbone to the ear, a landmark for facial bone scans.