Proposed Topic (Most preferred): :
Clinical Safety and Quality Service III (Projects aiming at quality service to patients and their carers)
Authors (including presenting author) :
Cheng KL(1), Leung SY(1)(2), Tong MH(1)(2), Hui MW(1)(3), Kwan CB(1)(3), Lee TF(1)(3), Chan TM(1)(3)
Affiliation :
(1)Department of Radiology, St. John Hospital, (2)Department of Radiology, Pamela Youde Nethersole Eastern Hospital, (3)Department of Radiology, Ruttonjee and Tang Shiu Kin Hospital
Introduction :
Regardless of the many uses and advantages of ionizing radiation in X-ray diagnostics, the ALARA (As Low As Reasonably Achievable) principle must be observed and is always a standard of practice that demonstrates expertise in minimizing radiation exposure to patients. Lumbar spine imaging is one of the examinations with the highest radiation exposure in plain radiography. It is a commonly requested examination for patients with low back pain. We focus on lumbar spine examinations as there are many radiosensitive organs located nearby including breasts, lungs, stomach, colon and gonads (1). Lumbar spine radiographs always generate effective radiation doses with an order of magnitude greater than other studies in general radiography examinations (Lumbar spine examination shows Typical Fetal Dose Range with 1.0 – 10 mGy). Various studies are conducted to reduce radiation dose whilst maintaining high diagnostic image quality for lumbar spine. A new Digital Radiography (DR) machine (DRX-Evolution Plus) with noise reduction function named Smart Noise Cancellation (SNC) is established in St. John Hospital. According to the manufacturer application team experience for machine setup, there is up to 24% radiation dose reduction compared to conventional DR after using SNC image processing function. The Exposure Control Factor (ECF) of Automatic Exposure Control (AEC) setup at the Image Processing Mode will be adjusted by default from 0 to -2 and resulted in reduced exposure factors when the SNC Processing Mode is on.
Objectives :
To investigate whether using the new SNC function that reduces 24% radiation dose compared to conventional DR imaging without affecting image quality for radiological diagnosis in lumbar spine imaging.
Methodology :
• A random trial basis study with retrospective study technique. • A total of 42 patients, the AP view and lateral view of lumbar spine region of lumbar sacral spine (L-S spine) examinations are reviewed from May to July 2023. All images are processed with DRX-Evolution Plus DR system. • Two groups of patients: Diagnostic images from 21 patients with L-S spine examination using SNC function and 21 patients with L-S spine examination without using SNC mode are commented by two radiologists. • The two radiologists commented the two views of L-S spine for each patient and obtain a total score for each case with reference to the European guidelines for lumbar spine examinations. • The collected result is compared with the use of SPSS for statistical analysis.
Result & Outcome :
1. The lumbar spine images are all commented adequate quality for radiological diagnosis. 2. The non-parametric test, Mann-Whitney U test is used. The median values of “patient with SNC score” and “patient without SNC score” are 21.5 vs 21.5 respectively for the average scores of the two radiologists. The difference between the median values is statistically not significant (p=0.263). Group Average Mean (median) from the two radiologists SNC 20.69 (21.5) No SNC 21.24 (21.5) There is no statistically significant difference between the image quality of two groups patients (with and without using SNC), whilst a 24% radiation dose reduction is achieved by using the new SNC image processing function compared to conventional DR imaging without affecting the image quality for radiological diagnosis in lumbar spine imaging. The limitation of our study includes a relatively small sample size. We are planning to further assess the impact of SNC on radiation dose reduction. 1. E Alukic, N Zalokar, N Mekis: Optimisation of Radiographic Procedures – Lumbar Spine Imaging in General Radiography. Medical Imaging and Radiotherapy Journal (MIRTJ). 2021; 38 (1)
