Roberto Blanco Sequeiros

Reliability of Readings of Magnetic Resonance Imaging Features of Lumbar Spinal Stenosis

Study Design. A reliability assessment of standardized magnetic resonance imaging (MRI) interpretations and measurements. Objective. To determine the intra- and inter-reader reliability of MRI features of lumbar spinal stenosis (SPS), including severity of central, subarticular, and foraminal stenoses, grading of nerve root impingement, and measurements of cross-sectional area of the spinal canal and thecal sac. Summary of Background Data. MRI is commonly used to assess patients with spinal stenosis. Although a number of studies have evaluated the reliability of certain MRI characteristics, comprehensive evaluation of the reliability of MRI readings in spinal stenosis is lacking. Methods. Fifty-eight randomly selected MR images from patients with SPS enrolled in the Spine Patient Outcomes Research Trial were evaluated. Qualitative ratings of imaging features were performed according to defined criteria by 4 independent readers (3 radiologists and 1 orthopedic surgeon). A sample of 20 MRIs was reevaluated by each reader at least 1 month later. Weighted &kgr; statistics were used to characterize intra- and inter-reader reliability for qualitative rating data. Separate quantitative measurements were performed by 2 other radiologists. Intraclass correlation coefficients and summaries of measurement error were used to characterize reliability for quantitative measurements. Results. Intra-reader reliability was higher than inter-reader reliability for all features. Inter-reader reliability in assessing central stenosis was substantial, with an overall &kgr; of 0.73 (95% CI 0.69–0.77). Foraminal stenosis and nerve root impingement showed moderate to substantial agreement with overall &kgr; of 0.58 (95% CI 0.53–0.63) and 0.51 (95% CI 0.42–0.59), respectively. Subarticular zone stenosis yielded the poorest agreement (overall &kgr; 0.49; 95% CI 0.42–0.55) and showed marked variability in agreement between reader pairs. Quantitative measures showed inter-reader intraclass correlation coefficients ranging from 0.58 to 0.90. The mean absolute difference between readers in measured thecal sac area was 128 mm2 (13%). Conclusion. The imaging characteristics of spinal stenosis assessed in this study showed moderate to substantial reliability; future studies should assess whether these findings have prognostic significance in SPS patients.

Does Lumbar Disc Degeneration on Magnetic Resonance Imaging Associate With Low Back Symptom Severity in Young Finnish Adults

Study Design. A cross-sectional magnetic resonance imaging study with questionnaires on low back pain (LBP) and functional limitations. Objective. To investigate the association between lumbar intervertebral disc degeneration (DD) and low back symptom severity among young Finnish adults. Summary of Background Data. Both LBP and lumbar DD are common already in adolescence, but very little is known of their association in young adults. Methods. Young adults belonging to a birth cohort (n=874) were invited to lumbar magnetic resonance imaging using a 1.5-T scanner. Data on LBP and functional limitations at the ages of 18, 19, and 21 years were used to cluster the subjects with respect to low back symptoms using latent class analysis. The prevalence and 95% confidence intervals of DD at 21 years and the sum score of DD at all lumbar levels were compared between the clusters. The contribution of DD and other imaging findings (herniations, anular tears, Modic changes, spondylolytic defects) to symptom severity was analyzed with logistic regression analysis. Results. Latent class analysis produced five clusters from the 554 subjects, ranging from a cluster where subjects (n=65) had been painful at all time points to an asymptomatic cluster (n=168). DD was more prevalent in the three most symptomatic clusters compared to the two least symptomatic ones. Similar findings were obtained for the DD sum scores. Lumbar DD was related to symptom severity independently of other degenerative findings. Moreover, moderately degenerated discs were more likely than mildly degenerated discs to be associated with the most severe low back symptoms. Conclusion. Intervertebral DD was associated with low back symptom severity among young adults, suggesting that the symptoms may have a discogenic origin at this age. However, DD was also found in one-third of asymptomatic subjects.

Reliability of magnetic resonance imaging readings for lumbar disc herniation in the Spine Patient Outcomes Research Trial (SPORT).

Study Design. Assessment of the reliability of standardized magnetic resonance imaging (MRI) interpretations and measurements. Objective. To determine the intra- and inter-reader reliability of MRI parameters relevant to patients with intervertebral disc herniation (IDH), including disc morphology classification, degree of thecal sac compromise, grading of nerve root impingement, and measurements of cross-sectional area of the spinal canal, thecal sac, and disc fragment. Summary of Background Data. MRI is increasingly used to assess patients with sciatica and IDH, but the relationship between specific imaging characteristics and patient outcomes remains uncertain. Although other studies have evaluated the reliability of certain MRI characteristics, comprehensive evaluation of the reliability of readings of herniated disc features on MRI is lacking. Methods. Sixty randomly selected MR images from patients with IDH enrolled in the Spine Patient Outcomes Research Trial were each rated according to defined criteria by 4 independent readers (3 radiologists and 1 orthopedic surgeon). Quantitative measurements were performed separately by 2 other radiologists. A sample of 20 MRIs was re-evaluated by each reader at least 1 month later. Agreement for rating data were assessed with kappa statistics using linear weights. Reliability of the quantitative measurements was assessed using intraclass correlation coefficients (ICCs) and summaries of measurement error. Results. Inter-reader reliability was substantial for disc morphology [overall kappa 0.81 (95% confidence interval (CI): 0.78, 0.85)], moderate for thecal sac compression [overall kappa 0.54 (95% CI: 0.37, 0.68)], and moderate for grading nerve root impingement [overall kappa 0.47 (95% CI: 0.36, 0.56)]. Quantitative measures showed high ICCs of 0.87 to 0.96 for spinal canal and thecal sac cross-sectional areas. Measures of disc fragment area had moderate ICCs of 0.65 to 0.83. Mean absolute differences between measurements ranged from approximately 15% to 20%. Conclusion. Classification of disc morphology showed substantial intra- and inter-reader agreement, whereas thecal sac and nerve root compression showed more moderate reader reliability. Quantitative measures of canal and thecal sac area showed good reliability, whereas measurement of disc fragment area showed more modest reliability.

Genetic susceptibility of intervertebral disc degeneration among young Finnish adults

BackgroundDisc degeneration (DD) is a common condition that progresses with aging. Although the events leading to DD are not well understood, a significant genetic influence has been found. This study was undertaken to assess the association between relevant candidate gene polymorphisms and moderate DD in a well-defined and characterized cohort of young adults. Focusing on young age can be valuable in determining genetic predisposition to DD.MethodsWe investigated the associations of existing candidate genes for DD among 538 young adults with a mean age of 19 belonging to the 1986 Northern Finland Birth Cohort. Nineteen single nucleotide polymorphisms (SNP) in 16 genes were genotyped. We evaluated lumbar DD using the modified Pfirrmann classification and a 1.5-T magnetic resonance scanner for imaging.ResultsOf the 538 individuals studied, 46% had no degeneration, while 54% had DD and 51% of these had moderate DD. The risk of DD was significantly higher in subjects with an allele G of IL6 SNPs rs1800795 (OR 1.45, 95% CI 1.07-1.96) and rs1800797 (OR 1.37, 95% CI 1.02-1.85) in the additive inheritance model. The role of IL6 was further supported by the haplotype analysis, which resulted in an association between the GGG haplotype (SNPs rs1800797, rs1800796 and rs1800795) and DD with an OR of 1.51 (95% CI 1.11-2.04). In addition, we observed an association between DD and two other polymorphisms, SKT rs16924573 (OR 0.27 95% CI 0.07-0.96) and CILP rs2073711 in women (OR 2.04, 95% CI 1.07-3.89).ConclusionOur results indicate that IL6, SKT and CILP are involved in the etiology of DD among young adults.

MRI-guided trephine biopsy and fine-needle aspiration in the diagnosis of bone lesions in low-field (0.23 T) MRI system using optical instrument tracking

Abstract. The purpose of this study was to evaluate the feasibility of MRI-guided bone biopsy with optical instrument tracking and evaluate advantage of combined fine-needle aspiration (FNA) with trephine biopsy. Twenty trephine bone biopsies and 13 FNAs were performed under MRI and CT guidance in 14 patients. Informed consent was obtained from all patients. The evaluation of diagnostic accuracy was achieved by comparing the histopathological and cytological diagnosis with current or final diagnosis made during 6-month clinical follow-up. A 0.23-T open MRI scanner with interventional tools (Outlook Proview, Marconi Medical Systems, Cleveland, Ohio) was used. A surface coil was used. For trephine biopsy MRI-compatible bone biopsy set (Daum medical, Schwerin, Germany) was used. The FNA was performed with MRI compatible 20-G needle (Cook, Bloomington, Ind.). The diagnostic accuracy of MRI-guided trephine biopsy was 95%. The FNA sample diagnosis concurred with the histological in 54%. Our results show that MRI guidance in bone biopsies is accurate and safe. It is comparable to CT-guided or open biopsy. The role of combined FNA with bone biopsies remains controversial.

Association of Modic Changes, Schmorl's Nodes, Spondylolytic Defects, High-Intensity Zone Lesions, Disc Herniations, and Radial Tears With Low Back Symptom Severity Among Young Finnish Adults

Study Design. A cross-sectional magnetic resonance imaging (MRI) study. Objective. We investigated the association among Modic changes, Schmorls nodes, spondylolytic defects, high-intensity zone lesions, radial tears, herniations, and low back symptom severity. Summary of Background Data. Disc degeneration is associated with low back pain in early adulthood, but the associations between other MRI findings and low back pain are not well known. Methods. Questionnaire data and MRI scans (1.5-T) were available for 554 subjects derived from a birth cohort at 21 years of age. Data on low back pain and back-related functional limitations at 18, 19, and 21 years of age were used for clustering of subjects, using latent class analysis. We used logistic regression with adjustment for the degree of disc degeneration to evaluate the associations between specific imaging findings and low back symptom severity. Results. The prevalence of herniations was 20%, Schmorls nodes 17%, radial tears 9.9%, high-intensity zone lesions 3.2%, spondylolytic defects 5.8%, and Modic changes 0.7%. Latent class analysis produced 5 clusters: “Always Painful” (n = 65) meant painful at all time points and “Recent Onset Pain” (n = 56) meant increasing symptom severity, whereas subjects in the “Moderately Painful” (n = 73), “Minor Pain” (n = 193), and “No Pain” (n = 167) clusters had fewer symptoms. Compared with the “No Pain” cluster, Schmorls nodes were more likely to occur in the “Always Painful” cluster (P = 0.017) and herniations in the 3 most painful clusters (P < 0.001). Herniations were associated with low back symptom severity (odds ratio, 2.5; 95% confidence interval, 1.4–4.4). Schmorls nodes and radial tears were associated with symptoms in crude analyses only, whereas high-intensity zone lesions and spondylolytic defects occurred in similar frequencies in all clusters. Conclusion. Herniations were most likely in the subjects with recent onset or persistent (3-yr period) low back symptoms, although they were also detected in subjects with no symptoms. The clinical relevance of herniations on MRI remains to be evaluated in the context of symptoms.

HIF Prolyl 4-Hydroxylase-2 Inhibition Improves Glucose and Lipid Metabolism and Protects Against Obesity and Metabolic Dysfunction

Obesity is a major public health problem, predisposing subjects to metabolic syndrome, type 2 diabetes, and cardiovascular diseases. Specific prolyl 4-hydroxylases (P4Hs) regulate the stability of the hypoxia-inducible factor (HIF), a potent governor of metabolism, with isoenzyme 2 being the main regulator. We investigated whether HIF-P4H-2 inhibition could be used to treat obesity and its consequences. Hif-p4h-2–deficient mice, whether fed normal chow or a high-fat diet, had less adipose tissue, smaller adipocytes, and less adipose tissue inflammation than their littermates. They also had improved glucose tolerance and insulin sensitivity. Furthermore, the mRNA levels of the HIF-1 targets glucose transporters, glycolytic enzymes, and pyruvate dehydrogenase kinase-1 were increased in their tissues, whereas acetyl-CoA concentration was decreased. The hepatic mRNA level of the HIF-2 target insulin receptor substrate-2 was higher, whereas that of two key enzymes of fatty acid synthesis was lower. Serum cholesterol levels and de novo lipid synthesis were decreased, and the mice were protected against hepatic steatosis. Oral administration of an HIF-P4H inhibitor, FG-4497, to wild-type mice with metabolic dysfunction phenocopied these beneficial effects. HIF-P4H-2 inhibition may be a novel therapy that not only protects against the development of obesity and its consequences but also reverses these conditions.

Association of Abdominal Obesity with Lumbar Disc Degeneration - A Magnetic Resonance Imaging Study

Purpose To evaluate whether midsagittal (abdominal) obesity in magnetic resonance imaging (MRI), waist circumference (WC) and body fat percentage are associated with lumbar disc degeneration in early adulthood. Methods We obtained the lumbar MRI (1.5-T scanner) of 325 females and 233 males at a mean age of 21 years. Lumbar disc degeneration was evaluated using Pfirrmann classification. We analysed the associations of MRI measures of obesity (abdominal diameter (AD), sagittal diameter (SAD), ventral subcutaneous thickness (VST), and dorsal subcutaneous thickness (DST)), WC and body fat percentage with disc degeneration sum scores using ordinal logistic regression. Results A total of 155 (48%) females and 147 (63%) males had disc degeneration. AD and SAD were associated with a disc degeneration sum score of ≥3 compared to disc degeneration sum score of 0–2 (OR 1.67; 95% confidence interval (CI) 1.20–2.33 and OR 1.40; 95% CI 1.12–1.75, respectively) among males, but we found no association among females. WC was also associated with disc degeneration among males (OR 1.03 per one cm; 95% CI 1.00–1.05), but not among females. Conclusion Measures of abdominal obesity in MRI and waist circumference were associated with disc degeneration among 21-year-old males.

Percutaneous MR‐guided discography in a low‐field system using optical instrument tracking: A feasibility study

To evaluate the feasibility of MRI‐guided discography with optical tracking.

MR-guided bone biopsy: Preliminary report of a new guiding method

To evaluate the feasibility of a new MR compatible optical tracking guided bone biopsy system.