3D MRI, Sagittal Sequence

These are selected images from the sagittal sequence. In the sagittal sequence, images are perpendicular to the line of sight when viewing the supine patient (with arms at the sides) from the shoulder toward the opposite shoulder.

The sagittal sequence cross-references the coronal and transverse sequences to display costoclavicular compression of the external jugular vein (XJ) against the bicuspid valve within the subclavian vein (SV) on the first rib (FR), costoclavicular compression of the axillary vein against the artery, interscalene triangle compression, and scarring (fibrosis) when present. The left and right sagittal images were selected to display the close proximity of the clavicle (C) to the external jugular (XJ) and subclavian veins (SV), particularly on the left. When the arms are elevated above the head, the posterior inferior rotation of the clavicles with the subclavius muscles efface and/or compress the venous drainage of the upper extremities. In these neutral images, the gray proton density (color) within the left subclavian vein (SV) reflects decreased venous flow as compared to the right subclavian vein.

A few labels have been placed on the image to assist with identification of landmark anatomy. The clavicles (C), external jugular vein (XJ), right lung (RL), left lung (LL), first ribs (FR), subclavian veins (SV), subclavian arteries (SA), and anterior scalene muscles (AS) are labeled for reference.