Glenohumeral Relationships during Physiologic Shoulder Motion and Stress Testing: Initial Experience with Open MR Imaging and Active Imaging-Plane Registration1
Christopher F. Beaulieu, MD, PhD,
Duncan K. Hodge, BA,
A. Gabrielle Bergman, MD,
Kim Butts, PhD,
Bruce L. Daniel, MD,
Clay L. Napper, MD,
Robert D. Darrow, MS,
Charles L. Dumoulin, PhD and
Robert J. Herfkens, MD
1 From the Department of Radiology (C.F.B., A.G.B., K.B., B.L.D., C.L.N., R.J.H.) and the School of Medicine (D.K.H.), Stanford University Medical Center, Rm S-056, 300 Pasteur Dr, Stanford, CA 94305; and the GE Corporate Research and Development Center, Schenectady, NY (R.D.D., C.L.D.). Received July 7, 1998; revision requested September 11; final revision received, October 27; accepted March 29, 1999. C.F.B. supported in part by a 1997 RSNA Scholar Award. A.G.B. supported in part by a 1997 Toshiba America/RSNA (1) Seed Grant. Address reprint requests to C.F.B.
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Figure 1a. Photographs demonstrate subject positioning in the vertically open MR imager. Subject sits between two doughnut-shaped magnet components, straddling the lower connector. Loop RF coil (arrowheads) is placed around the shoulder such that its magnetic field is perpendicular to the B0 direction (left to right in these photographs). Arm position (a) with approximately 80° glenohumeral abduction and (b) with 140° abduction.
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Figure 1b. Photographs demonstrate subject positioning in the vertically open MR imager. Subject sits between two doughnut-shaped magnet components, straddling the lower connector. Loop RF coil (arrowheads) is placed around the shoulder such that its magnetic field is perpendicular to the B0 direction (left to right in these photographs). Arm position (a) with approximately 80° glenohumeral abduction and (b) with 140° abduction.
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Figure 2. Representative oblique coronal fast gradient-echo dynamic MR images (19.8/7.2; flip angle, 30°) of the glenohumeral joint during abduction in an asymptomatic 26-year-old man. In the top left image, * marks the location of the MR tracking coil. Images show top left, 40°; top right, 68°; bottom left, 104°; and bottom right, 127° of total abduction. Measurement techniques are illustrated at top left, in which a circle is prescribed along the articular surface of the humeral head (H) to determine its geometric center (white dot). A line between the superior and inferior margins of the glenoid (G) is used to define its center. A perpendicular line from the humeral head center to the glenoid line allows measurement of translation in humeral head position relative to the glenoid center point. The degree of glenoid (scapular) and humeral elevation relative to the fully adducted position is determined by measuring and following the angles of the glenoid and a line prescribed along the humeral shaft (not shown) relative to the vertical axis of the image.
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Figure 3a. Graphs demonstrate glenohumeral motion patterns with (a) abduction and (b) adduction. For both abduction and adduction, the humeral head remained well centered on the glenoid, with fluctuations in position on the same order of magnitude as SDs of the measurements. Measurements of humeral head position relative to the center of the glenoid were made on serial oblique coronal images acquired during abduction and adduction motion in 10 asymptomatic shoulders. The glenoid center point is represented by 0 cm on the y axis. Positive translations from 0 cm indicate superior shifting of the humeral head, and negative values indicate inferior shifting. Data for different volunteers were pooled by breaking the abduction or adduction motion into 5° intervals and determining the mean humeral head position across patients within each angular increment. Individual data points represent, on average, three measurements within the increment of abduction or adduction (mean, 3.0 measurements ± 1.9; range, one to seven measurements). Vertical bars show the SD of the mean for each point.
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Figure 3b. Graphs demonstrate glenohumeral motion patterns with (a) abduction and (b) adduction. For both abduction and adduction, the humeral head remained well centered on the glenoid, with fluctuations in position on the same order of magnitude as SDs of the measurements. Measurements of humeral head position relative to the center of the glenoid were made on serial oblique coronal images acquired during abduction and adduction motion in 10 asymptomatic shoulders. The glenoid center point is represented by 0 cm on the y axis. Positive translations from 0 cm indicate superior shifting of the humeral head, and negative values indicate inferior shifting. Data for different volunteers were pooled by breaking the abduction or adduction motion into 5° intervals and determining the mean humeral head position across patients within each angular increment. Individual data points represent, on average, three measurements within the increment of abduction or adduction (mean, 3.0 measurements ± 1.9; range, one to seven measurements). Vertical bars show the SD of the mean for each point.
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Figure 4a. Transaxial fast gradient-echo dynamic MR images (19.8/7.2; flip angle, 30°) obtained through the center of the glenohumeral joint during internal and external rotation. Images show (a) 24°, (b) 48°, (c) 61°, and (d) 99° of external rotation. Measurement techniques are illustrated in a, in which a line defined by the anterior and posterior margins of the glenoid (1) determines its center point (arrow); another line perpendicular to the line through the humeral head defines the humeral head centering on the glenoid for different degrees of internal or external rotation (2). By using a line from the humeral head center through the bicipital groove (3), the rotation angle is determined relative to a line parallel to the glenoid face (4), identified as 0° rotation (6).
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Figure 4b. Transaxial fast gradient-echo dynamic MR images (19.8/7.2; flip angle, 30°) obtained through the center of the glenohumeral joint during internal and external rotation. Images show (a) 24°, (b) 48°, (c) 61°, and (d) 99° of external rotation. Measurement techniques are illustrated in a, in which a line defined by the anterior and posterior margins of the glenoid (1) determines its center point (arrow); another line perpendicular to the line through the humeral head defines the humeral head centering on the glenoid for different degrees of internal or external rotation (2). By using a line from the humeral head center through the bicipital groove (3), the rotation angle is determined relative to a line parallel to the glenoid face (4), identified as 0° rotation (6).
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Figure 4c. Transaxial fast gradient-echo dynamic MR images (19.8/7.2; flip angle, 30°) obtained through the center of the glenohumeral joint during internal and external rotation. Images show (a) 24°, (b) 48°, (c) 61°, and (d) 99° of external rotation. Measurement techniques are illustrated in a, in which a line defined by the anterior and posterior margins of the glenoid (1) determines its center point (arrow); another line perpendicular to the line through the humeral head defines the humeral head centering on the glenoid for different degrees of internal or external rotation (2). By using a line from the humeral head center through the bicipital groove (3), the rotation angle is determined relative to a line parallel to the glenoid face (4), identified as 0° rotation (6).
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Figure 4d. Transaxial fast gradient-echo dynamic MR images (19.8/7.2; flip angle, 30°) obtained through the center of the glenohumeral joint during internal and external rotation. Images show (a) 24°, (b) 48°, (c) 61°, and (d) 99° of external rotation. Measurement techniques are illustrated in a, in which a line defined by the anterior and posterior margins of the glenoid (1) determines its center point (arrow); another line perpendicular to the line through the humeral head defines the humeral head centering on the glenoid for different degrees of internal or external rotation (2). By using a line from the humeral head center through the bicipital groove (3), the rotation angle is determined relative to a line parallel to the glenoid face (4), identified as 0° rotation (6).
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Figure 5. Graph demonstrates glenohumeral motion patterns with internal and external (Int/Ext) rotation. Deviation in humeral head centering relative to the glenoid center is plotted as a function of the rotation angle. Measurements for the 10 shoulders were pooled by dividing the rotation motion into 10° increments; the mean was calculated by averaging across patients within each rotation increment. Each data point represents the mean of three to five individual measurements on a given shoulder. Vertical bars indicate SD from the mean for each value. Note that for these normal shoulders, the humeral head remained well centered on the glenoid during internal and external rotation.
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Figure 6. Photograph obtained at physical examination during MR imaging. Subject is seated with left shoulder toward the examiner. Examiner uses one hand to stabilize the scapula while the other applies anteroposterior or posteroanterior force to the humeral head.
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Figure 7a. Transaxial fast gradient-echo dynamic MR images (19.8/7.2; flip angle, 30°) of the glenohumeral joint obtained during application of force to the humeral head by a physician examiner. The subject was an asymptomatic 28-year-old woman. Images obtained with (a) no external force applied, (b) anteroposterior force on the humeral head (arrow), and (c) posteroanterior force on the humeral head (arrow). The center of the humeral head is indicated by a dot and the glenoid center by *. Measurement methods analogous to those used to obtain Figure 2 were used to quantify glenohumeral relationships. In b, the center of the humerus shifted 6 mm posteriorly relative to the glenoid center. In c, the center of the humeral head shifted 4 mm anteriorly relative to the glenoid center.
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Figure 7b. Transaxial fast gradient-echo dynamic MR images (19.8/7.2; flip angle, 30°) of the glenohumeral joint obtained during application of force to the humeral head by a physician examiner. The subject was an asymptomatic 28-year-old woman. Images obtained with (a) no external force applied, (b) anteroposterior force on the humeral head (arrow), and (c) posteroanterior force on the humeral head (arrow). The center of the humeral head is indicated by a dot and the glenoid center by *. Measurement methods analogous to those used to obtain Figure 2 were used to quantify glenohumeral relationships. In b, the center of the humerus shifted 6 mm posteriorly relative to the glenoid center. In c, the center of the humeral head shifted 4 mm anteriorly relative to the glenoid center.
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Figure 7c. Transaxial fast gradient-echo dynamic MR images (19.8/7.2; flip angle, 30°) of the glenohumeral joint obtained during application of force to the humeral head by a physician examiner. The subject was an asymptomatic 28-year-old woman. Images obtained with (a) no external force applied, (b) anteroposterior force on the humeral head (arrow), and (c) posteroanterior force on the humeral head (arrow). The center of the humeral head is indicated by a dot and the glenoid center by *. Measurement methods analogous to those used to obtain Figure 2 were used to quantify glenohumeral relationships. In b, the center of the humerus shifted 6 mm posteriorly relative to the glenoid center. In c, the center of the humeral head shifted 4 mm anteriorly relative to the glenoid center.
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Figure 8. Bar graph demonstrates glenohumeral deviation with stress testing. Mean values for humeral head deviation from the center of the glenoid were determined by averaging measurements across nine shoulders. Vertical bars indicate SD for the measurements. Note that a mean of approximately 4.5 mm deviation from the center was observed for both anteroposterior and posteroanterior forces. SDs, however, were relatively large, reflecting individual subject variations or differences in the amount of stress applied by the examiner. A-P = anteroposteriorly directed force, as illustrated in Figure 7b; Neutral = no force applied; P-A = posteroanteriorly directed force, as illustrated in Figure 7c.
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Copyright © 1999 by the Radiological Society of North America.
