Quality Assurance in Diagnostic Radiology

Quality Assurance in Diagnostic Radiology

Quality Assurance Test

Quality Assurance (QA) of medical diagnostic x-ray equipment means systematic actions necessary to provide adequate confidence to the end-user(s) that a medical diagnostic x-ray equipment will perform satisfactory in compliance with safety standards specified by the Competent Authority.

QA Program

The goal of QA Program is to ensure the accuracy of the diagnosis.

The minimum radiation dose should be delivered to the patient to achieve the objective of the diagnostic or interventional procedures.

QA program begins with the performance evaluation of diagnostic x-ray equipment at the manufacturing stage and then acceptance testing after the installation of X-ray equipment at user’s institution(s) to ensure its conformity with the specifications.

The QA tests should be carried out thereafter at regular intervals (periodicity-once in two years) and after repairs of the equipment or when equipment malfunction is suspected.

Objective of Quality Assurance

Optimum image quality of radiological procedures with minimum possible dose to the patient(s).

Why QA in Diagnostic Radiology?

To get calibrate all the exposure parameters, to check functional performance of X-ray equipment and radiation safety around the X-ray installation, QA checks are necessary for every diagnostic X-ray equipment. In other words, to obtain the optimum quality diagnostic information at the lowest radiation risk to the patient, QA of diagnostic X-ray equipment is necessary.

Quality Assurance Test

The routine QA tests are necessary to ensure that the functional performance of the equipment is like its baseline values and within the tolerance values as specified by regulatory body.

These tests should be performed by qualified service engineer(s) at user institution(s).

These tests should be performed at regular intervals (once in two years) and at major repairs of X-ray equipment.

Quality Assurance Tests for Diagnostic X-ray Equipment

Congruence of radiation and optical fields

Central beam alignment

Effective Focal spot size measurement

Timer Accuracy

Accuracy of Accelerating Tube Potential

Linearity of radiation output

Reproducibility of radiation output

Total filtration

Radiation leakage through tube housing

Exposure rate at tabletop

Fluoroscopic image quality parameters


Parameters affecting image quality

Operating Potential

Operating Current

Exposure Time

Effective Focal Spot Size

Total Filtration

Leakage from tube housing

Detector Characteristics