Assessment of Patient Doses in CR Examinations Throughout a Large Health Region

Abstract

Optimization and standardization of radiographic procedures in a health region minimizes patient exposure while producing diagnostic images. This report highlights the dose variation in common computed radiography (CR) examinations throughout a large health region. The RadChex cassette was used to measure the radiation exposure at the table or wall bucky in 20 CR rooms, in seven hospitals, using CR technology from two vendors. Exposures were made to simulate patient exposure (21 cm polymethyl methacrylate) under standard conditions for each bucky: 81 kVp at 100 cm for anteroposterior abdomen table bucky exposures (180 cm for posteroanterior chest wall bucky exposures), using the left, the right, or the center automatic exposure control (AEC) cells. Protocol settings were recorded. An average of 37% variation was found between AEC chambers, with a range between 4% and 137%. A 60% difference in dose was discovered between manufacturers, which was the result of the manufacture's image processing algorithm and subsequently corrected via software updates. Finally, standardizing AEC cell selection during common chest examinations could reduce patient dose by up to 30%. In a large health region, variation in exam protocols can occur, leading to unnecessary patient dose from the same type of examination. Quality control programs must monitor exam protocols and AEC chamber calibration in CR to ensure consistent, minimal, patient dose, regardless of hospital or CR vendor. Furthermore, this report highlights the need for communication between radiologists, technologists, medical physicist, service engineers, and manufacturers required to optimize CR protocols.

Patient‐based radiographic exposure factor selection: a systematic review

“…Optimal exposure is necessary for accurate diagnosis as well as adherence to the ALARA principle. Underexposed images results in increased quantum mottle, reduced image quality of the radiograph and may impede diagnosis . Overexposure reduces quantum mottle, improving image quality, and is less likely to be rejected by radiologists; thus there is a trend towards this technique .…”

Evaluation of Radiation Exposure From Computed Tomography of the Head

“…From The Journal of Digital Imaging, a case-control observational study conducted by Thakur et al (2012) highlighted the dose variation in common CT examinations throughout a large health region. RadChex was the device used to measure radiation exposure on patients already undergoing computed radiography.…”

“…Patients undergoing CT scans in twenty different CT rooms throughout seven hospitals were included in the study. Thakur et al (2012) identified up to 30% of a patient's radiation dose may be reduced with standardization of AEC device. Within a large health region, variation in exam protocols can occur, leading to unnecessary patient dose from the same type of examination (Thakur et al, 2012).…”

“…Thakur et al (2012) identified up to 30% of a patient's radiation dose may be reduced with standardization of AEC device. Within a large health region, variation in exam protocols can occur, leading to unnecessary patient dose from the same type of examination (Thakur et al, 2012). Quality control programs must monitor exam protocols and AEC chamber calibration in CT to ensure consistent, minimal, patient dose, regardless of hospital or CT vendor (Thakur et al, 2012).…”

“…Within a large health region, variation in exam protocols can occur, leading to unnecessary patient dose from the same type of examination (Thakur et al, 2012). Quality control programs must monitor exam protocols and AEC chamber calibration in CT to ensure consistent, minimal, patient dose, regardless of hospital or CT vendor (Thakur et al, 2012). Strength of the study was its use of various CT scanners in multiple hospitals.…”