Using MRI to evaluate anatomic significance of aortic bifurcation, right renal artery, and conus medullaris when locating lumbar vertebral segments.
OBJECTIVE
This study evaluated the anatomic significance and sites of aortic bifurcation, right renal artery, and conus medullaris when locating lumbar vertebral segments on MRI. SUBJECTS AND METHODS. The study group was composed of 210 patients who underwent MRI of the lumbosacral spine. The position of aortic bifurcation was evaluated using MRI. Midline and sagittal MRI were also assessed to identify the proximal portion of the right renal artery and the tip of the conus medullaris. These locations were recorded in relation to the upper or lower half of the adjacent vertebral body or the adjacent intervertebral disk space.


RESULTS
The most common site of aortic bifurcation was at the L4 vertebra (83%). In most patients two separated iliac arteries were apparent at the level of the L4-L5 disk space (93%), and the right renal artery was located between the lower half of the L1 vertebra and the upper half of the L2 vertebra (92%). The position of the conus medullaris was variably located, and the most frequent site was at the L1 vertebra (56%).


CONCLUSIONS
The aortic bifurcation, the right renal artery, and the combination of these structures can be reliable landmarks for determining the lumbar vertebral segments on MRI or CT. However, conus medullaris cannot be considered a good landmark because of its variable locations.
Lee
Chang Hee
CH
Department of Diagnostic Radiology, University of Konkuk, Chung-Ju Hospital, 620-5 Kyohyun-Dong, Chung-Ju City, Chung-Buk 380-704, South Korea. chlee86@kku.ac.kr
Seo
Bo Kyoung
BK
Choi
Young Chil
YC
Shin
Hyun Joon
HJ
Park
Jeong Hee
JH
Jeon
Hae Jeong
HJ
Kim
Kyeong Ah
KA
Park
Cheol Min
CM
Kim
Baek Hyun
BH
D000293:Adolescent; D000328:Adult; D000368:Aged; D001011:Aorta / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000033:anatomy & histology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012077:Renal Artery / Q000033:anatomy & histology*; D013116:Spinal Cord / Q000033:anatomy & histology*