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Diagnostic Imaging of Spinal Deformities: Reducing Patients Radiation Dose With a New Slot-Scanning X-ray Imager

Deschênes, Sylvain, PhD*; Charron, Guy, MSc; Beaudoin, Gilles, PhD; Labelle, Hubert, MD*; Dubois, Josée, MD, MSc*; Miron, Marie-Claude, MD*; Parent, Stefan, MD, PhD*

doi: 10.1097/BRS.0b013e3181bdcaa4

Study Design. 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.

Objective. 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.

Summary of Background Data. 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.

Methods. 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.

Results. 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).

Conclusion. We established that the EOS system offers overall enhanced image quality while reducing drastically the entrance dose for the patient.

Our study compares entrance dose and image quality of radiograph examinations prescribed for spinal deformity follow-ups. The results obtained from 50 patients show that a new slot-scanner provides images significantly better than a standard computed radiography system using 6 to 9 times less dose in the thoracolumbar region.

From the *Department of Medical Imaging, Centre Hospitalier Universitaire Sainte-Justine, Montreal, Quebec, Canada; and †Department of Radiology, Centre Hospitalier de l'Université de Montréal, Notre-Dame Hospital, Montreal, Quebec, Canada.

Acknowledgment date: February 24, 2009. Revision date: July 14, 2009. Acceptance date: July 20, 2009.

The device(s)/drug(s) is/are FDA-approved or approved by corresponding national agency for this indication.

Corporate/industry and other funds were received in support of this work. One or more of the author(s) has/have received or will receive benefits for subject of this manuscript: e.g. honoraria, gifts, consultancies.

Supported by This study obtained CHU Sainte-Justine's ethic committee approval. Informed consent was obtained from the patients, if over 18 years old. For minors, informed consent was obtained from the parent or guardian. The slot-scanning system evaluated in this paper was obtained through a grant from the Canadian Foundation for Innovation. The evaluation was supported through research funds by Biospace Med, the company producing the new slot-scanning device that is the subject of this manuscript. At the end of the study, Gilles Beaudoin and Sylvain Deschênes, the physicists working on this project, have come to a consulting agreement with Biospace Med.

Address correspondence and reprint requests to Sylvain Deschênes, PhD, Department of Medical Imaging, Centre Hospitalier Universitaire Sainte-Justine, 3175 Côte-Sainte-Catherine, Montreal, Quebec, Canada, H3T 1C5; E-mail:

© 2010 Lippincott Williams & Wilkins, Inc.