Diagnostic Imaging of Spinal Deformities

TLDR

The study aims to validate that the Biospace EOS slot‑scanning radiographic system delivers comparable or superior image quality while reducing radiation dose compared to a Fuji FCR 7501S computed radiography system in scoliosis examinations. In a prospective trial of 50 patients, the authors compared EOS and CR by acquiring matched lateral and posteroanterior images, measuring entrance dose at multiple anatomic sites with optically stimulated luminescence dosimeters, adjusting tube currents to equal signal‑to‑noise ratios on a phantom, and having two radiologists and two orthopedists evaluate image visibility on a four‑point scale. EOS reduced thoracoabdominal skin dose by 6–9 times and produced significantly better image quality for all structures in frontal and lateral views (P < 0.006 and P < 0.04, respectively), except lumbar spinous processes, which were better seen on CR (P < 0.003), confirming overall enhanced image quality and dose reduction.

Abstract

Clinical trial comparing image quality and entrance dose between Biospace EOS system, a new slot-scanning radiographic device, and a Fuji FCR 7501S computed radiography (CR) system for 50 patients followed for spinal deformities.Based on their physical properties, slot-scanners show the potential to produce image quality comparable to CR systems using less radiation. This article validates this assertion by comparing a new slot-scanner to a CR system through a wide-ranging evaluation of dose and image quality for scoliosis examinations.For each patient included in this study, lateral and posteroanterior images were acquired with both systems. For each system, entrance dose was measured for different anatomic locations.Dose and image quality being directly related, comparable images were obtained using the same radiograph tube voltage on both systems while tube currents were selected to match signal-to-noise ratios on a phantom. Different techniques were defined with respect to patient's thickness about the iliac crests. Given dose amplitudes expected for scoliosis examinations, optically stimulated luminescence dosimeters were chosen as optimal sensors. Two radiologists and 2 orthopedists evaluated the images in a randomized order using a questionnaire targeting anatomic landmarks. Visibility of the structures was rated on a 4 level scale. Image quality assessment was analyzed using a Wilcoxon signed-rank tests.Average skin dose was reduced from 6 to 9 times in the thoracoabdominal region when using the slot-scanner instead of CR. Moreover, image quality was significantly better with EOS for all structures in the frontal view (P < 0.006) and lateral view (P < 0.04), except for lumbar spinous processes, better seen on the CR (P < 0.003).We established that the EOS system offers overall enhanced image quality while reducing drastically the entrance dose for the patient.