Accuracy of dual-photon absorptiometry compared to computed tomography of the spine

Conference · Sun Jan 01 04:00:00 EST 1984 · J. Nucl. Med.; (United States)

OSTI ID:7088268

Mazess, R; Vetter, J; Towsley, M; Perman, W; Holden, J

Dual-photon absorptiometry (DPA) was done using Gd-153 (44 and 100keV) in vivo and on various bone specimens including 39 vertebrae and 24 femora. The precision error for triplicate determinations on individual vertebrae was 3.3%, 2.9%, and 1.7% for bone mineral content (BMC), projected area, and areal density of bone mineral (BMD) respectively. The accuracy of determinations was 3-4% on the femora and 5% on the vertebrae. Computed tomography (CT) determinations were done on seven vertebrae immersed in alcohol (50%) to simulate the effects of marrow fat. CT measurements were done using a dual-energy scanner (Siemens) from which single-energy data files also were analyzed. There was a high correlation between Gd-153 DPA scans and either single- or dual-energy CT scans of the same vertebrae (rapprox. =0.97). For dual-energy CT the determined bone values were only 2% higher than the Gd-153 DPA values; however, single-energy CT scans showed a marked deviation. The CT values at 75kVp were 38% lower than those obtained from dual-energy CT scans or from Gd-153 DPA scans, while the values at 125kVp were 46% lower. Calcium chloride solutions made up with 50% alcohol showed the same systematic error of single-energy CT. Dual-energy determinations are mandatory on trabecular bone in order to avoid the errors introduced by variable marrow fat. The magnitude of the latter error depends upon the energy of the CT scan.

• Research Organization: Dept. of Medical Physics, Univ. of Wisconsin, Madison, WI
• OSTI ID: 7088268
• Report Number(s): CONF-840619-
• Conference Information: Journal Name: J. Nucl. Med.; (United States) Journal Volume: 25:5
• Country of Publication: United States
• Language: English

Related Subjects

550602* -- Medicine-- External Radiation in Diagnostics-- (1980-)
62 RADIOLOGY AND NUCLEAR MEDICINE
ABSORPTION
ACCURACY
ALCOHOLS
ALKALINE EARTH METAL COMPOUNDS
ANIMAL TISSUES
BETA DECAY RADIOISOTOPES
BODY
BONE MARROW
CALCIUM CHLORIDES
CALCIUM COMPOUNDS
CALCIUM HALIDES
CHLORIDES
CHLORINE COMPOUNDS
COMPUTERIZED TOMOGRAPHY
DAYS LIVING RADIOISOTOPES
DIAGNOSTIC TECHNIQUES
ELECTRON CAPTURE RADIOISOTOPES
ELEMENTARY PARTICLES
ENERGY RANGE
ERRORS
EVEN-ODD NUCLEI
GADOLINIUM 153
GADOLINIUM ISOTOPES
HALIDES
HALOGEN COMPOUNDS
HEMATOPOIETIC SYSTEM
HYDROXY COMPOUNDS
IN VIVO
INTERMEDIATE MASS NUCLEI
ISOTOPES
KEV RANGE
KEV RANGE 10-100
MASSLESS PARTICLES
NUCLEI
ORGANIC COMPOUNDS
ORGANS
PHOTONS
RADIOISOTOPES
RARE EARTH ISOTOPES
RARE EARTH NUCLEI
SKELETON
TISSUES
TOMOGRAPHY
VERTEBRAE