Clinical Microwave Tomographic Imaging of the Calcaneus: A First-in-Human Case Study of Two Subjects

• Published in: IEEE transactions on biomedical engineering Vol. 59; no. 12; pp. 3304 - 3313
• Main Authors: Meaney, Paul M., Goodwin, Douglas, Golnabi, Amir H., Zhou, Tian, Pallone, Matthew, Geimer, Shireen D., Burke, Gregory, Paulsen, Keith D.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.12.2012; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Adult; Biological and medical sciences; Bone; bone density; Bone Density - physiology; Bones; Calcaneus - anatomy & histology; Calcaneus - diagnostic imaging; Calcaneus - pathology; Computed tomography; dielectric properties; Diseases of the osteoarticular system; Electric Conductivity; Electrical properties; Exact sciences and technology; Female; fracture risk; Fundamental areas of phenomenology (including applications); Humans; Image reconstruction; tomography; Imaging and optical processing; Imaging, Three-Dimensional - methods; Investigative techniques, diagnostic techniques (general aspects); Male; Medical sciences; Microwave imaging; Microwave measurements; Microwave theory and techniques; Microwaves; Optics; Osteoarticular system. Muscles; osteoporosis; Osteoporosis. Osteomalacia. Paget disease; Physics; Radiodiagnosis. Nmr imagery. Nmr spectrometry; Tomography - methods; Tomography, X-Ray Computed - methods; Ultrasonography; Human; Dielectric properties; Diseases of the osteoarticular system; Rupture; bone density; Fracture; Trauma; Calcaneum; fracture risk; Osteoarticular system; Case study; Osteoporosis; microwave imaging; Risk factor; Bone mineral density; Bone; Biomedical engineering
• DOI: 10.1109/TBME.2012.2209202
• ISSN: 0018-9294; 1558-2531

We have acquired 2-D and 3-D microwave tomographic images of the calcaneus bones of two patients to assess correlation of the microwave properties with X-ray density measures. The two volunteers were selected because each had one leg immobilized for at least six weeks during recovery from a lower leg injury. A soft-prior regularization technique was incorporated with the microwave imaging to quantitatively assess the bulk dielectric properties within the bone region. Good correlation was observed between both permittivity and conductivity and the computed tomography-derived density measures. These results represent the first clinical examples of microwave images of the calcaneus and some of the first 3-D tomographic images of any anatomical site in the living human.