Personalised 3D reconstruction of proximal femur from low-dose digital biplanar radiographs

Introduction:Patients with adolescent idiopathic scoliosis frequently receive X-ray imaging at diagnosis and subsequent follow monitoring. To achieve the ALARA concept of radiation dose, a biplanar low-dose X-ray system (BLDS) has been proposed. The aim of the study is to gather evidence on safety, accuracy and overall effectiveness of a BLDS compared with CT scanning, in a pediatric population, in order to support the final decision on possible acquisition of such innovative diagnostic system.Methods:The new method Decision-oriented HTA (DoHTA) was applied to carefully assess the diagnostic technology. It was developed starting from the EUnetHTA Core Model® integrated with the analytic hierarchy process in order to identify all the relevant assessment aspects of the technology involved, identified from scientific literature, experts’ judgments and specific context analysis of Bambino Gesù Children's Hospital. A weight was associated to each assessment element and the alternatives’ ranking was defined.Results:This innovative system provides orthopedic images in standing or sitting position, being able to examine the spine and lower limbs under normal weight-bearing conditions. This system is recommended for particular clinical indications as scoliosis and other congenital deformities of the spine. It is able to acquire simultaneous posteroanterior and lateral images in a single scan without vertical distortion and with lower radiation exposure than CT scanning. 2D images acquired can be combined to obtain a 3D reconstruction scanning based on a semi-automated statistical model.Conclusions:The major advantages of BLDS are the relatively low dose of radiation and the possibility of obtaining a 3D reconstruction of the bones. Our preliminary results show that data on the clinical effectiveness are limited but the technical advancements of BLDS appear promising in terms of patient management and patient health outcomes associated with its use.

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EOS: A NEW IMAGING SYSTEM WITH LOW DOSE RADIATION IN STANDING POSITION FOR SPINE AND BONE & JOINT DISORDERS

Journal of Musculoskeletal Research ◽

10.1142/s0218957710002430 ◽

2010 ◽

Vol 13 (01) ◽

pp. 1-12 ◽

Cited By ~ 36

Author(s):

Jean Dubousset ◽

Georges Charpak ◽

Wafa Skalli ◽

Jacques Deguise ◽

Gabriel Kalifa

Keyword(s):

3D Reconstruction ◽

Ct Scan ◽

Low Dose ◽

Imaging System ◽

Standing Position ◽

Lower Limbs ◽

Whole Body ◽

X Rays ◽

Low Dose Radiation ◽

Dose Radiation

Very precise combined work between multidisciplinary partners (radiation engineers in physics, engineers in biomechanics, medical radiologists and orthopedic pediatric surgeons) has led to the concept and development of a new low-dose radiation device named EOS. This device has three main advantages: (1) Thanks to the invention of Georges Charpak who designed gaseous detectors for X-rays, the reduction of dose necessary to obtain a good image of skeletal system was 8 to 10 times less for 2D imaging; compared to the dose necessary to obtain a 3D reconstruction from CT scan cuts, the reduction factor was 800 to 1000. (2) The accuracy of 3D reconstruction obtained is better than that of 3D reconstruction from CT scan cuts. (3) The patient in addition gets imaged in a standing functional position, thanks to the AP and lateral X-rays obtained from head to feet simultaneously. This is a big advantage compared to CT scans which are used only in lying position. From the simultaneous AP and lateral X-rays of the whole body obtained via the 3D bone external envelop technique, the biomechanics engineers obtain 3D reconstruction of every level of osteo-articular system, especially for spine, in standing position with an acceptable period of time for reconstruction. This (in spite of the evolution of standing MRI) allows more precise bone reconstruction in orthopedics, especially at the level of the entire skeleton, including the head, spine, pelvis, lower limbs, giving new consideration for physiology, physiopathology and therapeutics.

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