Advancements in Imaging Technology

What device converts x-rays into light?

scintillator

What is a scintillator composed of?

cesium iodide

What device converts light into digital signal?

photodiode array

What is a photodiode composed of?

amorphous silicon on a glass matrix

What term describes pixel size?

pixel pitch

What does bigger pixels equate to?

greater sensitivity

What are bigger pixels suited for?

cardiac

What does smaller pixels equate to?

finer detail

What are smaller pixels suited for?

radiography

What term describes the continuous flashing of light which refreshes the detector to eliminate a "ghost image”?

refresh light

How long can a photodiode retain a “ghost image” for?

45 s

How often does the refresh light go off?

every 30 ms

What phase describes the sequential and simultaneous read of images on photodiodes?

data transfer

What does KERMA stand for?

kinetic energy release (in) materials

What abbreviation describes the sum of initial kinetic energies of all charged particles let loose by uncharged ionizing radiation divided by the mass of the sample?

KERMA

What is the unit used for KERMA?

Gy

What term describes the amount of radiation at location before adjustment for external shielding?

free-in-air KERMA

When would 1 Gy equate to 100 rad?

when keV is less than 300

What term describes the KERMA in a given mass of air?

air KERMA

In air, how much exposure equates to 1 Gy of absorbed dose?

144 R

How much energy does ionizing radiation impart to 1 kg of tissue?

1 J

What is the average cumulative radiation dose from natural, medical and occupational sources?

2 mGy (0.002 Gy)

What pathology commonly results in stenosis/occlusion of 1 or both renal arteries?

FMD (fibromuscular dysplasia)

In what population is FMD commonly found?

caucasian females

How does FMD appear radiographically?

“beaded”

What pathology describes a blockage in the subclavian artery, leading to a back flow of blood?

SSS (subclavian steal syndrome)

How would the BP readings in the R and L limbs of a person with SSS be?

different

What is the number 1 cause of renal artery stenosis?

atherosclerosis

Where is atherosclerosis most prevalent?

2 cm of renal artery

What pathology describes high BP in the portal system from a blockage in the liver’s blood supply?

portal hypertension

What can portal hypertension result in?

blood backflow into the veins of the esophagus

In what vessel would a rupture be most life threatening?

varices in esophageal area

What pathology describes compression against the brachial plexus/artery, resulting in a nerve disorder?

thoracic outlet syndrome

What pathology describes poor circulation, leading to pain in the lower extremity with cramps in the calves?

claudication

What is the main source of potentially lethal pulmonary embolism?

deep vein thrombosis

What types of veins commonly become varicose veins?

superficial

What abnormal heart condition involves the RV increasing in size, leading to a high BP in the pulmonary vessels?

cor pulmonale

What pathology involves the narrowing of coronary arteries from O2 deprivation and ischemic heart disease

CAD (coronary artery disease)

What pathology is essentially chest pain?

angina pectoris

What is often the cause of angina pectoris?

sudden demand for O2

What pathology describes an abnormal accumulation of fluid in extravascular pulmonary tissues?

pulmonary edema

What is a common cause for a pulmonary edema?

elevation of pulmonary pressure from L heart failure (CHF)

What pathology describes the inability of the heart to pump blood at a sufficient rate and provide enough blood to tissues?

CHF (congestive heart failure)

What pathology describes an abnormal opening between the pulmonary artery and aorta?

PDA (patent ductus arteriosus)

What pathology describes a hole in intraventricular septum separating R and L ventricles?

ventricular septal defect

What is ventricular septal defect known to be?

most common cardiac congenital defect

What pathology describes a lesion on the mitral valve?

mitral regurgitation

What pathology describes dead tissue in the heart?

myocardial infarction