title: CT and MRI Determination of Intermuscular Space within Lumbar Paraspinal Muscles at Different Intervertebral Disc Levels.
abstract: BACKGROUND
  Recognition of the intermuscular spaces within lumbar paraspinal muscles is critically important for using the paramedian muscle-splitting approach to the lumbar spine. As such, it is important to determine the intermuscular spaces within the lumbar paraspinal muscles by utilizing modern medical imaging such as computed tomography (CT) and magnetic resonance imaging (MRI).
  
  
  METHODS
  A total of 30 adult cadavers were studied by sectional anatomic dissection, and 60 patients were examined using CT (16 slices, 3-mm thickness, 3-mm intersection gap, n = 30) and MRI (3.0T, T2-WI, 5-mm thickness, 1-mm intersection gap, n = 30). The distances between the midline and the superficial points of the intermuscular spaces at different intervertebral disc levels were measured.
  
  
  RESULTS
  Based on study of our cadavers, the mean distances from the midline to the intermuscular space between multifidus and longissimus, from intervertebral disc levels L1-L2 to L5-S1, were 0.9, 1.1, 1.7, 3.0, and 3.5 cm, respectively. Compared with the upper levels (L1-L3), the superficial location at the lower level (L4-S1) is more laterally to the midline (P<0.05). The intermuscular space between sacrospinalis and quadratus lumborum, and that between longissimus and iliocostalis did not exist at L4-S1. The intermuscular spaces in patients also varied at different levels of the lumbar spine showing a low discontinuous density in CT and a high signal in MRI. There were no significant differences between the observations in cadavers and those made using CT and MRI.
  
  
  CONCLUSIONS
  The intermuscular spaces within the paraspinal muscles vary at different intervertebral disc levels. Preoperative CT and MRI can facilitate selection of the muscle-splitting approach to the lumbar spine. This paper demonstrates the efficacy of medical imaging techniques in surgical planning.
authors.affiliation: Anatomical Institute of Minimally Invasive Surgery, Southern Medical University, Guangzhou, Guangdong, China; Department of Anatomy, Anhui Medical University, Hefei, Anhui, China.
authors.forename: Xuefei
authors.initials: X
authors.lastname: Deng
authors.affiliation: Department of Radiology, the 105th Hospital of PLA, Hefei, Anhui, China.
authors.forename: Youzhi
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Department of Orthopaedic Surgery, Shucheng People's Hospitial, Shucheng, Anhui, China.
authors.forename: Shidong
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Radiology, the 105th Hospital of PLA, Hefei, Anhui, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Anatomy, Anhui Medical University, Hefei, Anhui, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Han
authors.affiliation: Department of Orthopaedic Surgery, Shucheng People's Hospitial, Shucheng, Anhui, China.
authors.forename: Dengquan
authors.initials: D
authors.lastname: Zheng
authors.affiliation: Anatomical Institute of Minimally Invasive Surgery, Southern Medical University, Guangzhou, Guangdong, China.
authors.forename: Zihai
authors.initials: Z
authors.lastname: Ding
authors.affiliation: School of Medicine, Western Sydney University, Campbelltown, New South Wales, Australia.
authors.forename: Kelvin K L
authors.initials: KK
authors.lastname: Wong
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007403:Intervertebral Disc / Q000000981:diagnostic imaging*; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D064170:Paraspinal Muscles / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed; D055815:Young Adult