3D MRI, Transverse Oblique Sequence

These are selected images from the transverse oblique sequence (left and right). In the transverse oblique 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 hand. The imaging plane of the transverse oblique sequence is aligned to the course of the arteries, which allows a long continuous arterial segment to be viewed in a single image. Note that imaging the arteries also displays the nerves (such as the C8-T1 nerve roots, which are labeled in the images), since they bind to the arteries. Thus, compression of the subclavian artery also indicates compression of the brachial plexus. Compression of the subclavian artery is further a reflection of the compression of the venous drainage of the brachial plexus because veins are more compressible than arteries.

The transverse oblique sequence cross-references the coronal sequence to display costoclavicular compression of the external jugular vein against the bicuspid valve within the subclavian vein on the first rib. These images clearly display the tense backward displaced subclavian artery (SA) with binding nerve roots on the pleura with compression by the anterior scalene (AS), right greater than left. Observe the lower intensity gray signal of the subclavian artery (SA) in the region of the anterior scalene (AS) in the right view. The mildly dilated vertebral vein (VV) in the left view reflects increased collateral circulation. The images also display the close proximity of the axillary vein (AXV) to the axillary artery (AX, only labeled on left image) within the supraclavicular fossa posterior-medial to the pectoralis minor muscle (PMI), left greater than right.

A few labels have been placed on the image to assist with identification of landmark anatomy. The sternocleidomastoid muscles (STM), internal jugular veins (J), common carotid arteries (CC), external jugular vein (XJ), trachea (T), esophagus (E), anterior scalene muscles (AS), clavicles (C), subclavius muscles (SUB), axillary artery (AX), axillary veins (AXV), subclavian arteries (SA), C8-T1 nerve roots (C8-T1) which give rise to the ulnar nerves, vertebral vein (VV), spinal cord (SPC), first fascicle of the serratus anterior muscles (FSA), pectoralis minor muscles (PMI), right lung (RL), and left lung (LL) are labeled for reference.