Dose Reduction Protocol for Full Spine X-ray Examination Using Copper Filters in Patients With Adolescent Idiopathic Scoliosis. Issue 3 (1st February 2019)

• Record Type: Journal Article
• Authors: Minehiro, Kaori; Demura, Satoru; Ichikawa, Katsuhiro; Sasagawa, Takeshi; Takahashi, Naoki; Minami, Syuhei; Murakami, Hideki; Tsuchiya, Hiroyuki
• Is Part Of: Spine. Volume 44:Issue 3(2019)
• Publication Date: 2019-02-01
• Subjects: adolescent idiopathic scoliosis -- computed radiography -- copper filters -- full spine X-ray -- radiation exposure; Spine -- Abnormalities -- Periodicals; Spine -- Diseases -- Periodicals; Spine -- Surgery -- Periodicals; 616.73005
• DOI: 10.1097/BRS.0000000000002787
• Languages: English
• ISSNs: 0362-2436

Abstract

Abstract : Study Design: A prospective case series. Objective: The aim of this study was to assess a new protocol for full spine X-ray using copper (Cu) filters to reduce radiation exposure in patients with adolescent idiopathic scoliosis (AIS). Summary of Background Data: Radiation exposure is associated with an increased risk of cancer development in children. To reduce the radiation exposure without compromising the image quality using existing radiographic equipment, a new computed radiography protocol was optimized using a variety of heavy metal filters. Methods: Study 1: Whole spine radiographs were obtained using a human body phantom, and radiation doses without and with 0.1, 0.2, and 0.3 mm thick Cu filters were compared. Study 2: Patients with AIS who underwent posterior fusion were radiographically evaluated at follow-ups; the X-ray protocols with or without the use of 0.2-mm Cu filters were alternated between consecutive follow-ups. The image quality was independently evaluated using six points in the anterior–posterior (AP) view and seven in the lateral [left–right (LR)] view by three spine surgeons using a three-point grading system. Results: Study 1: The surface doses while obtaining nonfiltered X-rays in AP and LR views were 0.31 and 0.93 mGy, respectively, whereas those with 0.1-, 0.2-, and 0.3-mm Cu filters were 0.16 and 0.52, 0.11 and 0.36, and 0.08 and 0.27 mGy, respectively. Study 2: In patients with AIS, the percentage of grade 3 scores (both endplates were identifiable) on AP-view images was 85% with nonfiltered X-rays and 75% with the filtered X-rays. However, there were no significant differences between the two protocols. On LR images, the frequency of grade 3 scores was significantly lower at Th2 and Th12 on filtered images than on nonfiltered ones. Conclusion: Whole spine radiographs using 0.2-mm Cu filters in patients with AIS could reduce radiation exposure more than 60% while preserving the image quality. Level of Evidence: 4 Abstract : A new radiography protocol with 0.2−mm Cu filters was developed to reduce radiation exposure using the existing radiographic equipment. Whole spine radiographs of patients with adolescent idiopathic scoliosis acquired using this protocol showed >60% reduction in exposure with no change in image quality.