An anatomically realistic brain phantom for quantification with positron tomography
Phantom studies are useful in assessing and maximizing the accuracy and precision of quantification of absolute activity, assessing errors associated with patient positioning, and dosimetry. Most phantoms are limited by the use of simple shapes, which do not adequately reflect real anatomy. The authors have constructed an anatomically realistic life-size brain phantom for positron tomography studies. The phantom consists of separately fillable R + L caudates, R + L putamens, R + L globus passidus and cerebellum. These structures are contained in proper anatomic orientation within a fillable cerebrum. Solid ventricles are also present. The entire clear vinyl cerebrum is placed in a human skull. The internal brain structures were fabricated from polyester resin, with dimensions, shapes and sizes of the structures obtained from digitized contours of brain slices in the U.C.S.D. computerized brain atlas. The structures were filled with known concentrations of Ga-68 in water and scanned with our NeuroECAT. The phantom was aligned in the scanner for each structure, such that the tomographic slice passed through that structure's center. After calibration of the scanner with a standard phantom for counts/pixel uCi/cc conversion, the measured activity concentrations were compared with the actual concentrations. The ratio of measured to actual activity concentration (''recovery coefficient'') for the caudate was 0.33; for the putamen 0.42. For comparison, the ratio for spheres of diameters 9.5, 16,19 and 25.4 mm was 0.23, 0.54, 0.81, and 0.93. This phantom provides more realistic assessment of performance and allows calculation of correction factors.
- Research Organization:
- The Johns Hopkins Medical Institutions, Baltimore, MD
- OSTI ID:
- 6843417
- Report Number(s):
- CONF-840619-; TRN: 87-008892
- Journal Information:
- J. Nucl. Med.; (United States), Vol. 25:5; Conference: 31. annual meeting of the Society of Nuclear Medicine, Los Angeles, CA, USA, 5 Jun 1984
- Country of Publication:
- United States
- Language:
- English
Similar Records
A revised dosimetric model of the head and brain
Imaging opiate receptors with positron emission tomography
Related Subjects
61 RADIATION PROTECTION AND DOSIMETRY
CEREBELLUM
POSITRON COMPUTED TOMOGRAPHY
CEREBRUM
PHANTOMS
FABRICATION
ACCURACY
BLOOD VESSELS
CALIBRATION
DOSIMETRY
ERRORS
ORIENTATION
PATIENTS
POSITIONING
QUANTITY RATIO
SHAPE
BODY
BRAIN
CARDIOVASCULAR SYSTEM
CENTRAL NERVOUS SYSTEM
COMPUTERIZED TOMOGRAPHY
DIAGNOSTIC TECHNIQUES
EMISSION COMPUTED TOMOGRAPHY
MOCKUP
NERVOUS SYSTEM
ORGANS
STRUCTURAL MODELS
TOMOGRAPHY
550602* - Medicine- External Radiation in Diagnostics- (1980-)
655003 - Medical Physics- Dosimetry