on February 12, 2004
Published online before print February 12, 2004, doi: 10.1161/01.STR.0000116102.15636.65
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Submitted on August 30, 2003
From the Department of Clinical Neurosciences, Kyoto Takeda Hospital, Kyoto (T.S.); Department of Neurology, Kyoto Prefectural University of Medicine, Kyoto (N.T., T.M., M.N.); and Medical Engineering Laboratory, Tokyo Jikei University School of Medicine, Tokyo (H.F.), Japan. * To whom correspondence should be addressed. E-mail: shiogait{at}pop11.odn.ne.jp.
Background and Purpose--To clarify optimal brain tissue perfusion images visualized by transcranial ultrasound harmonic imaging, we compared gray-scale integrated backscatter (IBS) images of new ultraharmonic imaging (UHI) and conventional second harmonic imaging (SHI) with power harmonic imaging (PHI) (harmonic B-mode with harmonic power Doppler images) in 10 patients with and 4 without a temporal skull. Methods--Using a SONOS 5500 (Philips), we evaluated transient response images taken after a bolus Levovist injection at a horizontal diencephalic plane via temporal windows. Based on transmitting/receiving frequencies (MHz), 4 imaging procedures using an S3 transducer (SHI2.6 [1.3/2.6], UHI [1.3/3.6], PHI2.6 [1.3/2.6], and PHI3.2 [1.6/3.2]) and 2 imaging procedures using an S4 transducer (SHI3.6 [1.8/3.6] and PHI3.6 [1.8/3.6]) were compared in terms of size and location, peak intensity (PI), contrast area demarcation, and background image quality. Results--In intact skull cases, gray-scale imaging tended to show larger contrast areas than PHI. A large contrast area was most frequently observed in SHI2.6 images, despite there being more high-PI cases in UHI. No contrast area with unclear background was observed in a few cases. In craniectomized cases, all contrast images tended to have large and high PI compared with the intact skull cases. PHI, particularly PHI3.6, demonstrated sharper demarcation and a clearer background than gray-scale imaging. Conclusions--Transcranial gray-scale SHI using a low receiving frequency of 2.6 MHz is the superior method. PHI identifies contrast area localization better than gray-scale imaging and is particularly suitable for intraoperative and postoperative cases.
Accepted on November 4, 2003
Comparison of Transcranial Brain Tissue Perfusion Images Between Ultraharmonic, Second Harmonic, and Power Harmonic Imaging
Toshiyuki Shiogai MD*;
Key words: contrast media • perfusion, brain • imaging techniques • ultrasonography, Doppler, color, transcranial