Effect of the Head Reference Angle on the Mean Cerebral Blood Flow during Radionuclide-Angiography with the Patlak Plot Method with Technetium-99m Ethyl Cysteinate Dimer
Author(s): Hitoshi Hiraki, Toshimune Ito, Masahisa Onoguchi, Hirotatsu Tsuchikame, Masaaki Shishido, Takafumi Maeno, Hiroki Sanada, Masao Tago
Background: The purpose of this study was to clarify the effect of the head reference angle (jaw pull angle) in the cephalocaudal direction on mean cerebral blood flow (mCBF) during radionuclide (RI)-angiography using the Patlak Plot method in CBF Single Photon Emission Computed Tomography (SPECT) testing with 99mTc-ECD.
Methods: From January 2012 to December 2013, 290 normal patients were retrospectively evaluated with CBF SPECT testing with technetium-99m ethyl cysteinate dimer (99mTc-ECD). The brain Region of Interest (ROI) and mCBF were evaluated during RI-angiography.
Results: mCBF of all males and females aged 60–89 years was 40.4 ± 4.2 and 42.2 ± 3.6 (ml/100 g/min), respectively, showing a weak negative correlation with aging. The mCBF was lower in males than in females (p<0.05). The brain ROI size was significantly greater in males with a head reference angle below −10 degrees (p<0.05) and significantly smaller in males with an angle above 5.1degrees (p<0.05). Brain ROI size was significantly greater in females with a head reference angle below −10 degrees (p<0.05) and significantly smaller for females with an angle above 10 degrees (p<0.05). There was no significant difference in brain ROI sizes between males and females. The mCBF was significantly lower in both genders with head reference angle ±10 degrees (p<0.05).
Conclusion: The mCBF was found to be significantly lower when the head reference angle during RI-angiography using the Patlak Plot method and 99mTc-ECD was greater than ±10 degrees.