New method for improved reproducibility of ROI position in aorta, and automation of gamma fitting in BUR examination for non-invasive cerebral blood flow measurement

• Published in: Nippon Hōshasen Gijutsu Gakkai zasshi Vol. 59; no. 12; p. 1561
• Main Author: Odashima, Satoshi
• Format: Journal Article
• Language: Japanese
• Published: Japan 01.12.2003
• Subjects: Aged; Aorta, Thoracic - diagnostic imaging; Brain - metabolism; Calibration; Cerebrovascular Circulation; Cysteine - analogs & derivatives; Female; Humans; Image Processing, Computer-Assisted - methods; Male; Middle Aged; Organotechnetium Compounds; Radiopharmaceuticals; Reproducibility of Results; Subtraction Technique; Tomography, Emission-Computed, Single-Photon - methods
• ISSN: 0369-4305
• DOI: 10.6009/jjrt.KJ00000921688

The brain uptake ratio (BUR) is useful for non-invasive cerebral blood flow measurements. To obtain this ratio requires setting an ROI on the aorta to draw the time-activity curve (TAC). Previously, the ROI has been manually set, in order to avoid two undesirable positionings: 1) protrusion from the aorta and 2) overlap in a vein or lung. However, these manual methods are affected by operator subjectivity, which results in individual variations in TAC. In calculating the area under the curve (AUC), gamma fitting of TAC is also affected by operator subjectivity. These subjective operations are considered to be an important impediment to the reproducibility of AUC. Better reproducibility of AUC would lead to improved measurement of brain perfusion. In this study, two newly devised trials were undertaken: 1) defining a system for setting ROI on the aorta; 2) and automatic gamma fitting for TAC. As a result of these trials, the individual variation in AUC among operators decreased, and the reproducibility of AUC was enhanced.