Week 11 - PPT - Quality Control in Radiology

A set of flashcards covering topics related to Quality Control (QC) in radiology, including collimator operation, interlocks, table movement, compression devices, protective devices, PACS, calibration processes, and pixel correction.

What does the collimator operation QC test check for?

Smooth blade movement and automatic size adjustment when SID changes.

What is the purpose of x-ray room interlocks?

To prevent radiation exposure when the door is open.

How often should interlocks be tested?

Quarterly.

What is the acceptable accuracy for table angle indicators?

Within ±2° of the actual angle.

What should be checked about table movement?

It should operate smoothly between flat and upright positions.

What must compression devices be able to do during QC testing?

Move smoothly and easily in and out of the beam’s path.

What is the required lead equivalence for protective curtains/drapes at 100 kV?

At least 0.25 mm Pb.

What is the required lead equivalence for bucky slot covers?

At least 0.5 mm Pb.

How often are protective devices tested?

Quarterly.

Does this QC apply to personnel lead aprons?

No, only to fixed protective devices in the fluoroscopy room.

What should happen when the fluoroscopy tube is parked?

No radiation exposure should be possible.

What is tested during PACS QC?

Accuracy of archiving, image transmission, and monitor/printer resolution.

How often is PACS QC performed?

Weekly or monthly, depending on vendor recommendations.

What is a modality work list?

An automatically updated list of scheduled patients generated from the RIS.

Give one advantage and one disadvantage of the modality work list.

Advantage – reduces data entry errors; Disadvantage – can delay updates or cause reliance on unverified data.

What is offset calibration?

Removes dark current (electrical noise) by taking frames without radiation exposure.

How often should it be refreshed?

Automatically several times per day; manual frequency depends on vendor.

What is the purpose of gain calibration?

To ensure uniform detector response to x-rays across all pixels.

What are the typical exposure conditions for a flat field test?

70 kVp, 6 mAs, large SID, fully open collimation.

When is the gain calibration performed?

After the offset (dark noise) calibration.

What is the main purpose of pixel calibration?

To ensure all pixels display uniformly by correcting for defective or missing pixels.

How are defective pixels corrected?

By averaging the values of surrounding pixels.

When should pixel calibration be performed?

Only after the gain calibration test has passed.

For lab purposes, how recent must a QC test be to be considered valid?

Within the past year.