Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2000 Nov;11(3):207-13.
doi: 10.1002/1097-0193(200011)11:3<207::aid-hbm60>3.0.co;2-j.

Quantification of fMRI artifact reduction by a novel plaster cast head holder

V Edward  1 , C Windischberger, R Cunnington, M Erdler, R Lanzenberger, D Mayer, W Endl, R Beisteiner
Affiliations

Quantification of fMRI artifact reduction by a novel plaster cast head holder

V Edward et al. Hum Brain Mapp. 2000 Nov.

Abstract

In light of artifact-induced high variability of activation in fMRI repeat studies, we developed and tested a clinically useful plaster cast head holder (PCH) with improved immobilization, repositioning, and comfort. With PCH, there were considerably lower levels of translational and rotational head motion components compared to head fixation with conventional restraining straps (CRS). Rotational components cannot be fully compensated by realignment and lead to "false activations." In addition, task-correlated head motion, which highly increases the risk of artifacts, was considerably reduced with PCH, especially in a motion prone subject. Compared with PCH, head motion was 133% larger with CRS in a highly cooperative subject. With a motion prone subject, head motion range was increased by 769% (PCH: 0.9 mm, CRS: 7.8 mm), which may indicate the usefulness of PCH for restless patients. In functional activation maps, PCH alone yielded fewer residual motion artifacts than CRS + image registration. Subject tolerance of the head holder during the long measurement times of up to 2.5 hr was good, and slice orientation on different days confirmed the quality of repositioning.

PubMed Disclaimer

Figures

Figure 1
Figure 1
(a) Side view of plaster cast head holder; (b) Quarter view of plaster cast head holder; (c) Subject wearing plaster‐cast head holder latched into the MR head rest.
Figure 2
Figure 2
Time plots showing the translations and rotations of the head with PCH (thick lines) and CRS (dotted lines). Positive X, Y, and Z displacements (red, green, blue) indicate left, nasal, and cranial shifts, respectively. Pitch, Roll, and Yaw (red, green, blue) are rotations around the X (medio‐lateral), Y (anterior‐posterior), and Z (cranio‐caudal) axes, respectively.
Figure 3
Figure 3
Slice 7 of Subject 1 on three separate days. Despite the differences in signal intensity due to technical fluctuations, distortions due to the EPI sequence, as well as inaccuracies in MR bed repositioning a good repositioning in terms of slice orientation and offset is possible.
Figure 4
Figure 4
Close‐up of activation results for Subject 1 (comparable slices) (a) PCH + image registration, (b) PCH alone, (c) CRS + image registration, and (d) CRS alone are contrasted against each other. Interestingly, the apparent order of movement artifact contamination is (from highest to lowest) CRS, CRS + image registration, PCH alone, PCH + image registration. Note the slightly anteriorly rotated head position with CRS.
See this image and copyright information in PMC

References

    1. Ashburner H, Hutton C, Grootoonk S, Turner R, Friston KJ (1997): Correction for movement‐related effects arising from data interpolation in fMRI time‐series. Neuroimage 5(4) Part 2, 3rd International Conference on Functional Mapping of the Human Brain. S453.
    1. Beisteiner R, Gomiscek G, Erdler M, Teichtmeister C, Moser E, Deecke L (1995): Comparing localization of conventional functional magnetic resonance imaging and magnetoencephalography. Eur J Neurosci 7: 1121–1124. - PubMed
    1. Beisteiner R, Erdler M, Teichtmeister C, Diemling M, Moser E, Edward V, Deecke L (1997): Magnetoencephalography may help to improve functional MRI brain mapping. Eur J Neurosci 9: 1072–1077. - PubMed
    1. Bergström M, Greitz T (1976): Stereotactic computed tomography. Am J Roentgenol 127: 167–170. - PubMed
    1. Bergström M, Boethius J, Eriksson L, Greitz T, Ribbe T, Widen L (1981): Head fixation device for reproducible position alignment in transmission CT and positron alignment emission tomography. J Comput Assist Tomogr 5: 1136–1141. - PubMed

Publication types