Radiology and Medical Imaging Practice Flashcards

A comprehensive set of vocabulary flashcards covering diagnostic radiology, MRI, CT, nuclear medicine, and radiation safety based on lecture notes.

Radiation Officer

The member of the Radiology Department responsible for ascertaining all radiation guidelines and employing radiation safety measures.

Phototimer

A device used to control the reproducibility of images regardless of tissue density variations.

Differential absorption

The process responsible for the creation of the radiographic image.

Towne's projection

The best projection used to demonstrate a fracture in the occipital bone.

T1 weighted pulse sequence

The pulse sequence that best demonstrates contrast media (Gd) because it appears bright due to a short relaxation time.

Decreased lymphocytes

The clinical biologic effect resulting from an acute whole body exposure to $0.25\text{ sievert}$.

Colle's fracture

A fracture occurring in the distal radius.

Radon

The first decay product of radium.

Nosocomial

The term for an infection most likely acquired in healthcare facilities.

$$0$$

The CT number for water when expressed as a Houndsfield Unit (HU).

Isomeric transition

The principal decay mode of $^{99m}\text{Tc}$.

Scoliosis

The terminology for an abnormal lateral curvature of the vertebral column.

Intensifying screens

Components that convert X-rays to light.

Orthopnea

The sensation of breathlessness while in a recumbent position.

Achalasia

A motor disorder where peristalsis is reduced along the distal two-thirds of the oesophagus.

Angiogram

A diagnostic study used to show blood vessels.

$$10,000\text{ gauss}$$

The equivalent value of $1\text{ Tesla}$ in gauss units.

$$63.9\text{ MHz}$$

The precession frequency of hydrogen at a $1.5\text{ tesla}$ magnetic field strength ($B_0$).

Prospective gating

A method used in cardiac CT imaging to lower the radiation dose to the patient.

Transient cavitation

The type of cavitation in ultrasonography most likely to cause biologic damage.

Quenching

The sudden loss of absolute zero temperature in the MRI magnet coil leading to helium escaping from the cryogen.

Diverticulum

Small sacs developed in the wall of the colon.

ALARA

An acronym standing for 'As low as reasonably achievable' regarding radiation protection.

Gray ($\text{Gy}$)

The unit used to measure absorbed dose.

Seldinger

The most frequently used method for vascular catheterization.

$$1\text{ mR/hour}$$

According to the inverse square law, the exposure rate at $10\text{ meters}$ if the exposure is $4\text{ mR/hour}$ at $5\text{ meters}$.

Sialography

The radiographic examination of the salivary glands using contrast media.

$$25\%$$

The effect on radiographic density if the distance between the X-ray tube and image receptor is doubled while other factors remain constant.

Hypovolemic shock

The type of shock resulting from severe bleeding.

$$0.024\text{ mSv}$$

The effective dose if an organ receives $0.2 mSv$ and the lung weighting factor is $0.12$.