scholarly journals Variability in the size of the retroperitoneal oblique corridor: A magnetic resonance imaging-based analysis

2020 ◽  
Vol 11 ◽  
pp. 54
Author(s):  
Zain Boghani ◽  
William III Steele ◽  
Sean M. Barber ◽  
Jonathan J. Lee ◽  
Olumide Sokunbi ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Lumbar Spine ◽  
Magnetic Resonance ◽  
Psoas Muscle ◽  
Resonance Imaging ◽  
Medial Aspect ◽  
Disc Space ◽  
Invasive Approach ◽  
Major Vessel ◽  
Iliac Bifurcation

Background: A minimally invasive approach to the L2-S1 disc spaces through a single, left-sided, retroperitoneal oblique corridor has been previously described. However, the size of this corridor varies, limiting access to the disc space in certain patients. Here, the authors retrospectively reviewed lumbar spine magnetic resonance imaging (MRI) in 300 patients to better define the size and variability of the retroperitoneal oblique corridor. Methods: Lumbar spine MRI from 300 patients was reviewed. The size of the retroperitoneal oblique corridor from L2-S1 was measured. It was defined as the (1) distance between the medial aspect of the aorta and the lateral aspect of the psoas muscle from L2-L5 and (2) the distance between the midpoint of the L5-S1 disc and the medial aspect of the nearest major vessel on the left at L5-S1. In addition, the rostral-caudal location of the iliac bifurcation was measured. Results: The size of the retroperitoneal oblique corridor at L2/3, L3/4, L4/5, and L5/S1 was, respectively, 17.3 ± 6.4 mm, 16.2 ± 6.3 mm, 14.8 ± 7.8 cm, and 13.0 ± 8.3 mm. The incidence of corridor size <1 cm at L2/3, L3/4, L4/5, and L5/S1 was 10.3%, 16.0%, 30.0%, and 39.3%, respectively. The iliac bifurcation was most commonly found behind the L4 vertebral body (n = 158, 52.67%) followed by the L4/5 disc space (n = 74, 24.67%). Conclusion: The size of the retroperitoneal oblique corridor diminishes in a rostral-caudal direction, often limiting access to the L4/5 and L5/S1 disc spaces.

scholarly journals Psoas Morphology Differs between Supine and Sitting Magnetic Resonance Imaging Lumbar Spine: Implications for Lateral Lumbar Interbody Fusion

2018 ◽  
Vol 12 (1) ◽  
pp. 29-36 ◽  
Author(s):  
Aaron J. Buckland ◽  
Bryan M. Beaubrun ◽  
Evan Isaacs ◽  
John Moon ◽  
Peter Zhou ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Lumbar Spine ◽  
Magnetic Resonance ◽  
Intervertebral Disc ◽  
Interbody Fusion ◽  
Lumbar Fusion ◽  
Psoas Muscle ◽  
Lumbar Interbody Fusion ◽  
Resonance Imaging ◽  
Lateral Lumbar Interbody Fusion

<sec><title>Study Design</title><p>Retrospective radiological review.</p></sec><sec><title>Purpose</title><p>To quantify the effect of sitting vs supine lumbar spine magnetic resonance imaging (MRI) and change in anterior displacement of the psoas muscle from L1–L2 to L4–L5 discs.</p></sec><sec><title>Overview of Literature</title><p>Controversy exists in determining patient suitability for lateral lumbar interbody fusion (LLIF) based on psoas morphology. The effect of posture on psoas morphology has not previously been studied; however, lumbar MRI may be performed in sitting or supine positions.</p></sec><sec><title>Methods</title><p>A retrospective review of a single-spine practice over 6 months was performed, identifying patients aged between 18–90 years with degenerative spinal pathologies and lumbar MRIs were evaluated. Previous lumbar fusion, scoliosis, neuromuscular disease, skeletal immaturity, or intrinsic abnormalities of the psoas muscle were excluded. The anteroposterior (AP) dimension of the psoas muscle and intervertebral disc were measured at each intervertebral disc from L1–L2 to L4–L5, and the AP psoas:disc ratio calculated. The morphology was compared between patients undergoing sitting and/or supine MRI.</p></sec><sec><title>Results</title><p>Two hundred and nine patients were identified with supine-, and 60 patients with sitting-MRIs, of which 13 patients had undergone both sitting and supine MRIs (BOTH group). A propensity score match (PSM) was performed for patients undergoing either supine or sitting MRI to match for age, BMI, and gender to produce two groups of 43 patients. In the BOTH and PSM group, sitting MRI displayed significantly higher AP psoas:disc ratio compared with supine MRI at all intervertebral levels except L1–L2. The largest difference observed was a mean 32%–37% increase in sitting AP psoas:disc ratio at the L4–L5 disc in sitting compared to supine in the BOTH group (range, 0%–137%).</p></sec><sec><title>Conclusions</title><p>The psoas muscle and the lumbar plexus become anteriorly displaced in sitting MRIs, with a greater effect noted at caudal intervertebral discs. This may have implications in selecting suitability for LLIF, and intra-operative patient positioning.</p></sec>

Influence of preoperative statins and aspirin administration on biological and magnetic resonance imaging properties in patients with abdominal aortic aneurysm

VASA ◽  
2020 ◽  
pp. 1-9
Author(s):  
Milos Sladojevic ◽  
Petar Zlatanovic ◽  
Zeljka Stanojevic ◽  
Igor Koncar ◽  
Sasenka Vidicevic ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Abdominal Aortic Aneurysm ◽  
Magnetic Resonance ◽  
Aortic Aneurysm ◽  
Signal Intensity ◽  
Psoas Muscle ◽  
Resonance Imaging ◽  
Maximal Diameter ◽  
Aneurysm Wall ◽  
Abdominal Aortic

Summary: Background: Main objective of this study was to evaluate the influence of statins and/or acetylsalicylic acid on biochemical characteristics of abdominal aortic aneurysm (AAA) wall and intraluminal thrombus (ILT). Patients and methods: Fifty patients with asymptomatic infrarenal AAA were analyzed using magnetic resonance imaging on T1w sequence. Relative ILT signal intensity (SI) was determined as a ratio between ILT and psoas muscle SI. Samples containing the full ILT thickness and aneurysm wall were harvested from the anterior surface at the level of the maximal diameter. The concentration of enzymes such as matrix metalloproteinase (MMP) 9, MMP2 and neutrophil elastase (NE/ELA) were analyzed in ILT and AAA wall; while collagen type III, elastin and proteoglycan 4 were analyzed in harvested AAA wall. Oxidative stress in the AAA wall was assessed by catalase and malondialdehyde activity in tissue samples. Results: Relative ILT signal intensity (1.09 ± 0.41 vs 0.89 ± 0.21, p = 0.013) were higher in non-statin than in statin group. Patients who were taking aspirin had lower relative ILT area (0.89 ± 0.19 vs 1.13. ± 0.44, p = 0.016), and lower relative ILT signal intensity (0.85 [0.73–1.07] vs 1.01 [0.84–1.19], p = 0.021) compared to non-aspirin group. There were higher concentrations of elastin in AAA wall among patients taking both of aspirin and statins (1.21 [0.77–3.02] vs 0.78 (0.49–1.05) ng/ml, p = 0.044) than in patients who did not take both of these drugs. Conclusions: Relative ILT SI was lower in patients taking statin and aspirin. Combination of antiplatelet therapy and statins was associated with higher elastin concentrations in AAA wall.

scholarly journals THU0492 MAGNETIC RESONANCE IMAGING OF THE SACROILIAC JOINTS IN PATIENTS WITH HYPERMOBILITY: A RETROSPECTIVE COHORT STUDY

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 482.4-483
Author(s):  
A. Jones ◽  
C. Ciurtin ◽  
H. Kazkaz ◽  
M. Hall-Craggs
Keyword(s):  
Magnetic Resonance Imaging ◽  
Bone Marrow ◽  
Back Pain ◽  
Lumbar Spine ◽  
Magnetic Resonance ◽  
Bone Marrow Oedema ◽  
Resonance Imaging ◽  
Sacroiliac Joints ◽  
Fatty Change ◽  
Subchondral Sclerosis

Background:The incidence of inflammatory and structural lesions on magnetic resonance imaging of sacroiliac joints (MRI SIJs) in patients with hypermobility related disorders has not been fully investigated. Hypermobile patients are more susceptible to pelvic instability and biomechanical stress of the SIJs, leading to MRI SIJ changes similar to those occurring in spondyloarthritis (SpA). Patients with hypermobility and suspected SpA pose a unique challenge owing to the high prevalence of back pain in the hypermobility cohort and the absence of spinal restriction on clinical examination.Objectives:In this study, we aim to investigate the incidence of MRI SIJ lesions in patients with hypermobility.Methods:We performed a retrospective study of all patients with a confirmed diagnosis of hypermobility related disorders (including hypermobility syndrome, hypermobility spectrum disorders and Ehlers-Danlos Syndromes) referred for an MRI lumbar spine and SIJ between 2011 and 2019 to investigate long-standing back pain. MRIs were examined by a musculoskeletal (MSK) radiologist with more than 25 years of experience, who was blinded to the clinical outcome of the patients. MRI SIJs were assessed for the presence of bone marrow oedema, subchondral sclerosis, erosion, fatty change, enthesitis, ankylosis, joint fluid and capsulitis.Results:51 patients with confirmed hypermobility related disorders were referred for MRI SIJ and lumbar spine between 2011 and 2019. 3 patients demonstrated clinical features in keeping with a diagnosis of SpA and were excluded from the study. 15/48 (31.3%) of patients with hypermobility and back pain (but no clinical picture of SpA) were found to have inflammatory and/or structural lesions on MRI SIJ. The most frequent lesions were small foci of bone marrow oedema (16.6%) followed by subchondral sclerosis (12.5%) and fatty change (10.4%). The incidence of erosions was 4.2%.Conclusion:There is a relatively high incidence of inflammatory and structural lesions on MRI SIJ of patients with hypermobility. The presence of hypermobility should be taken into consideration when interpreting MRI changes in patients with suspected SpA. Further research into long-term outcomes of MRI SIJs in patients with hypermobility and back pain is required to establish the clinical significance of these findings.Disclosure of Interests: :Alexis Jones: None declared, Coziana Ciurtin Grant/research support from: Pfizer, Consultant of: Roche, Modern Biosciences, Hanadi Kazkaz: None declared, Margaret Hall-Craggs: None declared

Magnetic Resonance Imaging of Trauma to the Thoracic and Lumbar Spine The Importance of the Posterior Longitudinal Ligament

Spine ◽  
1992 ◽  
Vol 17 (5) ◽  
pp. 541-550 ◽  
Author(s):  
Rebecca P. Brightman ◽  
Carole A. Miller ◽  
Gary L. Rea ◽  
Donald W. Chakeres ◽  
William E. Hunt
Keyword(s):  
Magnetic Resonance Imaging ◽  
Lumbar Spine ◽  
Magnetic Resonance ◽  
Posterior Longitudinal Ligament ◽  
Resonance Imaging ◽  
Thoracic And Lumbar Spine
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