Fig 1.
Raw sonographic images and a schematic drawing showing the midbrain (mesencephalic brainstem) in two participants.
A) Control participant. The substantia nigra ipsilateral to the probe (the side at which the planimetric measurement is made) is encircled with a dotted line. B) Schematic drawing of image A showing anatomical landmarks and measurement parameters. The area shaded in dark gray represents the cross-sectional area of the midbrain. C) Methamphetamine participant. * Cerebral aqueduct. Raphe, echogenicity of midline structures.
Table 1.
Participant characteristics in the control and methamphetamine groups.
Fig 2.
Group data showing the midbrain and substantia nigra measurements on the right and left side and largest side.
The boundary of each box represents the 25th and 75th percentile and the whiskers (error bars) represent the 10th and 90th percentiles. The solid line within each box is the median. A and B) Area of substantia nigra (SN) echogenicity in the control group (A) and methamphetamine group (B). C and D) Cross-sectional area of the whole midbrain in the control group (C) and methamphetamine group (D). E and F) Interpeduncular angle in the control group (E) and methamphetamine group (F).
Table 2.
Results of the mixed effects models showing the main effects of, and interactions between, group, sex, and side for whole midbrain area and area of substantia nigra echogenicity.
Fig 3.
Individual data showing the relationship between midbrain characteristics (whole midbrain area and interpeduncular angle) and the area of substantia nigra (SN) echogenicity.
A and B) Relationship between the whole midbrain area and area of SN echogenicity in the control group (A) and methamphetamine group (B). C and D) Relationship between interpeduncular angle and area of SN echogenicity in the control group (C) and methamphetamine group (D). Circles, males. Triangles, females.
Table 3.
Results of the mixed effects models showing the main effects of whole midbrain area, interpeduncular angle, side, group, and sex on the log transformed area of substantia nigra echogenicity.
Table 4.
Inter-rater reliability for whole midbrain area and interpeduncular angle.