Diagnostic imaging of spinal deformities: reducing patients radiation dose with a new slot-scanning X-ray imager.
METHODS
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.


BACKGROUND
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).


CONCLUSIONS
We established that the EOS system offers overall enhanced image quality while reducing drastically the entrance dose for the patient.
Department of Medical Imaging, Centre Hospitalier Universitaire Sainte-Justine, 3175 Côte-Sainte-Catherine, Montreal, Quebec, Canada. sylvain.deschenes@recherche-ste-justine.qc.ca
Sylvain
S
Deschênes
Guy
G
Charron
Gilles
G
Beaudoin
Hubert
H
Labelle
Josée
J
Dubois
Marie-Claude
MC
Miron
Stefan
S
Parent
D004307:Dose-Response Relationship, Radiation; D006801:Humans; D011829:Radiation Dosage; D011856:Radiographic Image Enhancement / Q000295:instrumentation*; D011857:Radiographic Image Interpretation, Computer-Assisted; D012600:Scoliosis / Q000000981:diagnostic imaging*; D013131:Spine / Q000000981:diagnostic imaging*; D011795:Surveys and Questionnaires; D014057:Tomography, X-Ray Computed / Q000295:instrumentation*