Reconsidering high intensity zones: its role in intervertebral disk degeneration and low back pain.

PURPOSE: High intensity zones (HIZ) in the lumbar intervertebral disk (IVD) can be associated with degenerative changes which may ultimately manifest as low back pain (LBP). However, the relationship between the prevalence of HIZ and lumbar degenerative parameters is still unclear. The purpose of this study was to determine the prevalence of HIZ in the lumbar spine, analyze the independent relationship between HIZ and lumbar degenerative parameters measured on MRI and X-ray and determine the association between HIZ and the presence of LBP. METHODS: A retrospective review of MRI data, X-ray data, and radiology reports for 136 consecutively recruited patients, above 18-years-age and with both lumbar MRI and X-ray scans was conducted. 57 patients with HIZ were identified. Patients without HIZ (n = 79) made up the control group. RESULTS: HIZ was prevalent in 41.9% of patients and in 11.0% of all lumbar IVDs. The odds of developing HIZ were 6.4 (Exp(B) 6.4, 95%CI [3.157-12.988]) and 3.0 (Exp(B) 3.0, 95%CI [1.603, 5.674]) times higher in IVDs with disk bulge/protrusion and nucleus degeneration, respectively. Odds of HIZ was also increased in disks with larger IVD angle (Exp(B) 1.1, 95%CI [1.034, 1.169]). The odds of patients presenting to imaging with LBP was 3.0 (OR 3.0, 95%CI [1.478-6.338]) times higher in the HIZ compared to the control group. CONCLUSIONS: HIZ was prevalent in 41.9% of participants that were recruited in this study. Nucleus degeneration, disk bulge/protrusion and increased IVD angle were found to be independently associated with HIZ and since there is an increased likelihood of LBP, we posit that HIZ is likely a symptomatic and clinically meaningful diagnostic tool in the assessment of LBP.

The correlation between the lumbar disc MRI high-intensity zone and discogenic low back pain: a systematic review and meta-analysis.

OBJECTIVE: This study aimed to investigate the correlation between the MRI high-intensity zone (HIZ) and the pathogenesis of discogenic low back pain. METHODS: Literature from PubMed, EMBASE, Cochrane Library, Science Direct, China Knowledge Network, Wanfang Database, and China Biomedical Literature Database was searched until August 2023. Cohort studies including patients with low back pain who underwent lumbar spine MRI and discography, as well as the results evaluating the correlation between HIZ and discography for morphological changes in the disc and pain replication phenomena, were included in the analysis. The literature that met the inclusion criteria was screened, and the methodological quality of the included studies was evaluated. Meta-analysis of the extracted data was performed by using RevMan 5.1.1. RESULTS: In total, 28 reports were included in this meta-analysis. There was a statistically significant correlation between a positive HIZ and abnormal disc morphology in discography (OR 28.15, 95% CI [7.38, 107.46], p < 0.00001). Patients with HIZ-positive discs had a significantly higher incidence of consistent pain (71.0%, 969/1365) than those with HIZ-negative imaging (29.0%, 1314/4524) (OR 7.71, 95% CI [5.29, 11.23], p < 0.00001).Segments that were HIZ-positive and had abnormal disc morphology had a higher incidence of consistent pain (86.1%, 230/267) than HIZ-negative subjects (32.2%, 75/233) (OR 14.09, 95% CI [2.12, 93.48], p = 0.006). CONCLUSION: A positive MRI T2-weighted image of the lumbar disc with HIZ indicates disc degeneration. In addition, HIZ may be a specific indicator for the physical diagnosis of discogenic low back pain. A more advanced degree of disc degeneration on the basis of HIZ positivity corresponded to a greater probability of discography-induced consistent pain, whereas the degree of disc degeneration on the basis of HIZ negativity was less correlated with contrast-induced consistent pain.

Imaging Analysis of the High-Intensity Zone on Lumbar Spine Magnetic Resonance Images: Classification, Features and Correlation with Low Back Pain.

AIM: Early studies suggested that the high-intensity zone (HIZ) on lumbar MRI was a diagnostic sign of painful internal disc disruption (IDD). However, recent studies have questioned its diagnostic value. This study is conducted to explore imaging features of HIZ and to investigate the correlation between these characteristics and low back pain (LBP), further studying the predictive value of HIZ. METHODS: A retrospective study of 1188 cases was performed. MR images were read and analyzed by two experienced, blinded radiologists. RESULTS: A total of 575 (48.4%) individuals exhibited HIZ. The prevalence of posterior HIZ (32.3%) was significantly higher than that of anterior HIZ (23.6%; P < 0.01). Round type was the most common shape (61.0%) on sagittal view. Only 37 HIZs (4.6%) were identified on axial views. A total of 263 HIZ discs (32.5%) were found to have additional diagnostic signs of IDD, which is difficult to distinguish from the annulus fibrosus. In subjects with consecutive slides showing HIZ, the incidence of LBP was significantly higher than in single-slide HIZ individuals (58.0% vs 48.6%, P < 0.05). CONCLUSION: MRI-visualized HIZ is a highly valuable method of screening for lumbar IDD. It is demonstrated that consecutive-slide HIZ was a more reliable indicator for discogenic LBP than single-slide HIZ.

Alleviating Paravertebral Muscle Spasm after Radiofrequency Ablation Treatment of Hypersensitive Basivertebral and Sinuvertebral Nerves for Chronic Discogenic Back Pain.

BACKGROUND: Paraspinal muscle spasm caused by pain from a lumbar degenerative disc is frequently investigated in patients with low back pain. Radiofrequency ablation (RFA) surgery could alleviate paraspinal muscle spasms. OBJECTIVES: We performed RFA surgery on the high-intensity zone (HIZ) and hypersensitive sinuvertebral and basivertebral nerves to evaluate its outcome. The paravertebral muscle cross-sectional area (CSA) was measured on magnetic resonance imaging (MRI) before and after surgery to evaluate the effect of RFA surgery on the paravertebral muscle. STUDY DESIGN: Prospective cohort study. SETTING: A single spine surgery center. METHODS: A comparative study was performed on 2 different uniportal spinal endoscopic surgery groups; 23 patients who underwent RFA surgery for chronic discogenic back pain and 45 patients who underwent posterior decompression surgery for lumbar spinal stenosis with 12 months of follow-up. Paravertebral muscle cross-sectional area, Schiza grade, Modic type, and HIZ size were measured on pre- and post-operative MRI. An endoscopic video review was performed to evaluate the presence of intraoperative twitching and grade the degree of epidural neovascularization and adhesion. Visual analog scale VAS, modified Oswestry Disability Index, ODI and MacNab's criteria were evaluated for outcome measures. RESULTS: Intraoperative endoscopic video evaluation showed neovascularization and adhesion adjacent to the disc and pedicle. In the RFA surgery group, there were 7 patients (30.43%) with grade 2 and 16 (69.57%) with grade 3 neovascularization; intraoperative twitching was observed in 19 out of 23 patients (82.61%). After performing an RFA on the sinuvertebral and basivertebral nerves for the treatment of discogenic back pain, the results showed significant improvement in pain and disability scores. The mean CSA of the paraspinal muscle in the RFA surgery group was significantly increased after surgery at the L4-L5 and L5-S1 levels (L4-L5: 3901 ± 1096.7 mm² to 4167 ± 1052.1 mm², P = 0.000; L5-S1: 3059 ± 968.5 mm² to 3323 ± 1046.2 mm², P = 0.000) compared to preoperative CSA. LIMITATIONS: This study was limited by its small sample size. CONCLUSION: Hypersensitive sinuvertebral and basivertebral nerves are strongly associated with epidural neovascularization with adhesion and the pathological pain pathway in degenerative disc disease. Epidural neovascularization with adhesion reflects aberrant neurological connections, which are associated with reflex inhibitory mechanisms of the multifidus muscle, which induces spasm. RFA treatment of the region of epidural neovascularization with adhesion effectively treated chronic discogenic back pain and could induce paraspinal muscle spasm release.

Factors Predicting the Clinical Outcome After Trans-sacral Epiduroscopic Laser Decompression for Lumbar Disc Herniation.

OBJECTIVE: Previous literatures have demonstrated widely variable clinical results after transsacral epiduroscopic laser decompression (SELD) and the factors predicting outcomes are not yet established. Therefore, we analyzed the clinical outcome and associated predictive factors of SELD in patients with lumbar disc herniation. METHODS: Between 2015 and 2018, 82 patients who underwent single-level SELD and followed up at least 6 months were enrolled. The overall success rate (excellent or good results at final follow-up) was 58.5% according to Odom's criteria. Based on this result, patients were divided to 2 groups: a favorable group (n = 48) and an unfavorable group (n = 34). A retrospective review of the baseline characteristics and clinical outcome were conducted to reveal the predictive factors. RESULTS: As expected, improvement of pain and patient satisfaction, was more favorable in the favorable group (p < 0.05). Moreover, the rate of additional procedure was lower in the favorable group (4.2%, 2 of 48 patients) than in the unfavorable group (35.3%, 12 of 34 patients) (p = 0.011). Among the various baseline characteristics, the only significant predictive factor for favorable outcome was the presence of a high-intensity zone (HIZ) on preoperative magnetic resonance imaging (50.0% [24 of 48 patients] in the favorable group vs. 11.8% [4 of 34 patients] in the unfavorable group; odds ratio, 15.67; p = 0.024). CONCLUSION: Although SELD for lumbar disc herniation resulted in a less favorable clinical outcome than that reported in previous studies, in patients with a HIZ, SELD can be an effective minimally invasive surgery to relieve low back pain and/or leg pain.

Full-endoscopic Spine Surgery for Discogenic Low Back Pain with High-intensity Zones and Modic Type 1 Change in a Professional Baseball Player.

Non-specific low back pain in athletes can be caused by discogenic back pain, Modic type 1 change, and facet joint arthritis. In this report, we describe a full-endoscopic surgical strategy that we have used to treat a patient with both discogenic pain and Modic type 1 change. The patient was a 32-year-old professional baseball player who played an infield position and had a 2-year history of low back pain. Three years earlier, he had undergone micro-endoscopic discectomy for left herniated nucleus pulposus at L5/S1. His leg symptoms resolved postoperatively, and he returned to playing baseball the following season. However, his low back pain gradually increased. Two years after the initial surgery, he was experiencing low back pain in daily life and found it very difficult to play baseball. Short T1 inversion recovery (STIR) magnetic resonance imaging (MRI) revealed Modic type 1 change and high-signal intensity zones in degenerated discs at L4/5 and L5/S1. Injection of xylocaine 1% reduced the pain temporarily, confirming that the pain generator was at L4/5 and L5/S1. The pathological diagnosis was discogenic pain with Modic type 1 change. We performed full-endoscopic disc cleaning (FEDC) surgery for the Modic type 1 change and thermal annuloplasty (TA) for the discogenic pain at these levels. The patient's low back pain decreased steadily thereafter. Six months after surgery, he returned to baseball, playing for a full season without pain. We have successfully treated a professional baseball player with discogenic pain and Modic type 1 change by full-endoscopic surgery.

Lumbar Annular High-Intensity Zone as a Precursor to Disc Extrusion.

Low back pain (LBP) is a common affliction with numerous causes. Some individuals experience LBP attributed to disc pathology. Disc pathology has been implicated in a plurality of cases of LBP, and some cases are associated with annular fissures (AFs). AFs are weaknesses in the structure that contains the nucleus pulposus and is the site of possible disc herniations. On magnetic resonance imaging (MRI), some AFs manifest as the high-intensity zone (HIZ), otherwise known as an annular enhancement region. In this report, we present three patients with LBP, mild radiculitis, and HIZ who later developed herniated nucleus pulposus (HNP) with extrusion through the HIZ. These cases suggest that HIZ indicates a propensity for the future development of disc extrusion through the weakened tissue at the AF visualized as HIZ on MRI. With a better understanding of the association between AFs and disc herniations with HIZ, clinicians may be able to predict and prevent the pain and disability associated with disc extrusion.

Evaluation of transforaminal epidural steroid injections for discogenic axial lumbosacral back pain utilizing PROMIS as an outcome measure.

BACKGROUND CONTEXT: Discogenic lumbosacral back pain continues to present a challenging clinical entity with limited, controversial therapeutic options. No study to date has evaluated the efficacy of fluoroscopically guided transforaminal epidural steroid injections (TFESI) in a homogenous patient population with axial lumbosacral back pain from discogenic pathology utilizing strict, explicitly clinical and radiographic criteria. Additionally, there is a paucity of published data utilizing Patient Reported Outcome Measurement Information System (PROMIS) scores as an outcome measure for interventional spine procedures. PURPOSE: Evaluate the therapeutic effect of TFESIs in a specific subset of patients with discogenic axial lumbosacral back pain. Investigate PROMIS as an outcome measure for interventional spine procedures targeting focal degenerative spinal pathology. STUDY DESIGN/SETTING: Retrospective review of patients presenting to a multidisciplinary, tertiary academic spine center. PATIENT SAMPLE: Three thousand eight hundred eighty-one patients were screened for inclusion. A total of 26 patients with discogenic axial low back, based on strict clinical and radiographic criteria, underwent TFESIs. All patients had axial low back pain without radicular pain, ≥3 clinical features of discogenic pain, corroborative radiographic features of active discogenic pathology on lumbar spine magnetic resonance imaging without confounding spinal pathology. OUTCOME MEASURES: PROMIS Pain Interference (PI) v1.1, PROMIS Physical Function (PF) v1.2/v2.0, and PROMIS Depression (D) v1.0 outcome scores were collected at baseline and postprocedure follow-up. METHODS: Query of an institutional, patient reported outcome database and subsequent retrospective review of electronic medical records was performed. Statistical analysis comparing baseline and postprocedural PROMIS outcome scores and correlation between these instruments was performed. Additionally, an exploratory investigation of minimal clinically important difference achievement rates was performed. RESULTS: Analysis determined a statistically significant improvement in PROMIS PI (p=.017, 95% CI=-8.02 to -1.82) and PROMIS PF (p=.003, 95% CI=0.91-8.72) scores after treatment with TFESIs. At post treatment time points, TFESI had medium effect size on pain (d=0.55) and function (d=0.59). Change in PROMIS D scores (p=.488, 95% CI -1.74-3.54; d=.08) did not demonstrate statistical significance. Pearson correlation demonstrated a moderate negative correlation (r=-0.544, p=.004) between PROMIS PF with PROMIS PI. Correlation between PROMIS PF (r=-0.239, p=.24) and PROMIS PI (r=0.198, p=.33) with PROMIS D was not significant. Fourteen (53.8%) and 9 (34.6%) subjects achieved minimum clinically important difference (MCID) for PROMIS PI and PROMIS PF, respectively. Nine subjects (34.6%) achieved MCID for PROMIS D despite not otherwise reaching statistical significance otherwise. CONCLUSIONS: Utilizing PROMIS as an outcome measure, discogenic axial lumbosacral back pain patients appear to benefit from TFESI in terms of pain and physical function. This study contributes to the growing body of literature utilizing PROMIS scores in patients with clinical sequelae of degenerative spinal pathology; however, prospective studies are needed.

Anterior High-Intensity Zone in Lumbar Discs: Prevalence and Association with Low Back Pain.

OBJECTIVES: To explore the features of high-intensity zone (HIZ) in anterior annulus fibrosus and assess the association of anterior HIZ with low back pain (LBP). DESIGN, SETTING, AND SUBJECTS: A retrospective study of 5,940 discs in 1,188 individuals was conducted. METHODS: Subjects' information and LBP symptoms confirmed by an orthopedic surgeon were acquired from the medical record. Magnetic resonance (MR) image reading and analysis were performed by two experienced blinded radiologists. RESULTS: Two hundred eighty individuals exhibited 355 anterior HIZs in 355 discs. The prevalence was 23.57%; 88.45% were located in the inferior part of the annulus fibrosus. It frequently occurred in the middle and upper segments of lumbar spine, especially at L3/4 (45.63%). Of the 355 anterior HIZs, only 79 (22.25%) were consecutive-slides HIZ. Round type (63.38%) was the most common shape of anterior HIZs. The highest prevalence was found in individuals aged 60-69 years. LBP was confirmed in 141 anterior-HIZ individuals. The incidence of LBP in anterior-HIZ individuals was significantly higher than in non-HIZ subjects (50.36% vs 35.24%, χ2 = 18.314, P < 0.001). CONCLUSIONS: Anterior HIZ is a lower-prevalence, age-related sign on lumbar MR images. The spatial distribution of anterior HIZ can be distinguished from posterior HIZ. The number of consecutive anterior HIZ slides might suggest fewer Dallas grade 4 anterior annular disruptions in this sample. Anterior HIZ was correlated with LBP.

Postoperative Outcomes After Transsacral Epiduroscopic Laser Decompression in Japanese Patients: Denervation Therapy for Discogenic Low-Back Pain.

Background: Transsacral epiduroscopic laser decompression (SELD) is a very noninvasive surgery, so it is effective for elderly patients and athletes and is a new and minimally invasive therapeutic technique that may be useful in many patients with discogenic low-back pain (LBP) having high signal intensity zone (HIZ) in magnetic resonance imaging (MRI). We investigated the clinical outcomes of SELD in Japanese patients with discogenic LBP having HIZ as a first trial. Methods: The subjects consisted of 52 patients who underwent SELD and were followed up for at least 6 months. All patients with LBP with HIZ were operative using the SELD technique. Outcomes of the patients were assessed with visual analogue scale (VAS) for LBP, the Oswestry disability index (ODI), and the EuroQol 5 dimension (EQ-5D). Statistical analyses were carried out using a paired t-test. A p-value of <0.05 was considered significant. For statistical analysis, we used the SPSS software program. Results: At 12 months after the procedure, the average VAS score for LBP fell to 1.2 from 5.6 (p-value <0.05). The ODI score also dropped from the preoperative level of 22.3 to 8.8. The EQ-5D score also significantly increased from the preoperative level of 0.865 (SD 0.10) to 0.950 (SD 0.05). Eight cases of intraoperative cervical pain were observed as complications with no cases of hematomas, infections, and postoperative neurosis was observed. Conclusions: SELD provides a novel minimally invasive technique capable of performing multilevel intervertebral surgery. We believe that SELD is an effective method of treating discogenic LBP due to HIZs.

Lumbar high-intensity zones on MRI: imaging biomarkers for severe, prolonged low back pain and sciatica in a population-based cohort.

BACKGROUND CONTEXT: There is often discrepancy between clinical presentation and lumbar magnetic resonance imaging (MRI) findings. PURPOSE: The purpose of this study was to assess the relationship of high-intensity zones (HIZs) on MRI with low back pain (LBP), sciatica, and back-related disability. STUDY DESIGN: Cross-sectional, population-based Southern Chinese cohort study. PATIENT SAMPLE: Of 1,414 possible participants, data from 1,214 participants (453 males, 761 females; mean age of 48.1±6.3 years) were included. OUTCOME MEASURES: Presence of single-level, homogeneous multilevel (same type HIZs of morphology and topography) and heterogeneous multilevel (mixed type HIZs of morphology and topography) HIZs and other MRI phenotypes were assessed at each level with T2-weighted 3T sagittal MRI of L1-S1. Associations with LBP, sciatica and Oswestry Disability Index were correlated with HIZ profiles. RESULTS: In all, 718 individuals had HIZs (59.1%). Disc degeneration/displacement were more prevalent in HIZ individuals (p<.001). HIZ subjects experienced prolonged severe LBP more frequently (39.6% vs. 32.5%; p<.05) and had higher Oswestry Disability Index scores (10.7±13.7 vs. 8.9±11.3; p<.05). Posterior multilevel HIZ were significantly associated with prolonged severe LBP (OR: 2.18; 95% CI:1.42-3.37; p<.05) in comparison to anterior only, anterior/posterior or other patterns of HIZ. Multilevel homogeneous or heterogeneous HIZs were significantly associated with prolonged, severe LBP (OR: 1.53-1.57; p<.05). Individuals with homogeneous HIZs had a higher risk of sciatica (OR: 1.51, 95% CI: 1.01-2.27; p<.05). CONCLUSIONS: This is the first large-scale study to note that lumbar HIZs, and specific patterns therein, are potentially clinically-relevant imaging biomarkers that are independently and significantly associated with prolonged/severe LBP and sciatica. HIZs, especially homogenous multilevel HIZ, should be noted in the global pain imaging phenotype assessment.

Five-year development of lumbar disc degeneration-a prospective study.

OBJECTIVE: To examine the impact of demographic, clinical, and genetic factors as well as herniated discs on 5-year development of disc degeneration in the lumbar spine, and to investigate associations between changes in lumbar degenerative findings and pain. MATERIALS AND METHODS: In 144 patients with lumbar radicular pain or low back pain, we scored disc degeneration, herniated discs, and high-intensity zones in the posterior annulus fibrosus on lumbar magnetic resonance imaging (MRI) at baseline and 5-year follow-up. Genotyping (TaqMan assay) was performed for genes encoding vitamin D receptor (VDR), collagen XIα (COL11A), matrix metalloproteinase 1/9 (MMP1/MMP9), and interleukin 1α/1RN (IL-1α/IL-1RN). Associations were analyzed using multivariate linear regression adjusted for age, sex, smoking, body mass index, and baseline scores for degenerated discs and herniated discs (when analyzing impact of baseline factors) or for pain (when analyzing associations with pain). RESULTS: Progression of disc degeneration over 5 years was significantly (p < 0.001) related to higher age and less disc degeneration at baseline, but not to sex, smoking, body mass index, herniated discs, or variants in the studied genes. No associations were identified between changes in disc degeneration or high-intensity zones and pain at 5-year follow-up. However, increased number of herniated discs over 5 years was associated with pain at rest (p = 0.019). CONCLUSIONS: Age and disc degeneration at baseline, rather than genetic factors, influenced the 5-year development of disc degeneration in patients with lumbar radicular pain or low back pain. Development of herniated discs was related to pain at rest.

Factors associated with lumbar disc high-intensity zone (HIZ) on T2-weighted magnetic resonance image: a retrospective study of 3185 discs in 637 patients.

BACKGROUND: It is well known that internal disc disruption (IDD) is accelerated by factors such as aging and injury. High- intensity zone (HIZ) on lumbar MRI is usually considered a marker of painful IDD. However, many painful IDD show no HIZ. This suggests that the risk factors of HIZ may be different to these of IDD. The purpose was to clarify the correlation between the HIZ on lumbar MR and the factors, including gender, age, body weight, and low back pain (LBP). METHODS: Characteristics were obtained from the medical record. The MR images, biplanar post-discography radiographs, and post-discography CT images were reviewed and rated by two experienced radiologists in a blinded fashion. RESULTS: Annular HIZ correlated significantly with age (OR = 1.011), body weight (OR = 1.022), and LBP symptom (OR = 1.527). The lowest two HIZ prevalence rates were in the second and the third decades (11.54% and 7.84%). The highest prevalence was in the sixth decade (38.03%). The body weight was positively associated with the HIZ prevalence. There was a significant difference in HIZ prevalence between symptomatic and asymptomatic patients (36.16% vs. 26.96%, P < 0.05). All the HIZ discs exhibited grade 3 or grade 4 disruptions, but only 9 discs (9/16, 8 exhibited grade 4 annular tears) were detected with exact pain reproduction. CONCLUSIONS: It is demonstrated that the presence of HIZ on lumbar MR image was associated with aging, high body weight, and low back pain symptom. HIZ sign indicated a part of the natural history of disc degeneration but was not an actual source of low back pain.

[Changes in shape and signal intensity of high intensity zone in lumbar intervertebral discs on magnetic resonance images: a longitudinal study].

OBJECTIVE: To investigate changes over time in the shape and signal intensity of high intensity zone (HIZ) in the lumbar intervertebral discs on magnetic resonance images in patients with low back pain. METHODS: The imaging data were collected from 27 patients with low back pain, who underwent lumbar magnetic resonance (MR) imaging examinations that identified HIZ lesions and received follow-up MR examinations at least 1.5 years later over the period from January 2009 to January 2017. The initial and follow-up MR T2WI images of the patients were read by two experienced radiologists to categorize the changes in the shape of the HIZ lesions into enlarged, unchanged, shrunk, and disappeared. The volume and signal/cerebrospinal fluid signal intensity (T2/CSF) ratio of the HIZ were measured on sagittal MR images using ImageJ software. RESULTS: Of the 43 HIZ lesions found in the initial examinations, 22 (51.2%) remained unchanged in the follow-up examinations, 10 (21.3%) were enlarged, 9 (20.9%) shrank, and 2 (23.3%) disappeared. The follow-up examinations revealed 4 new HIZ lesions in the intervertebral discs. The volumes of these lesions did not vary significantly in the follow-up examinations (P=0.653), but the T2/CSF ratio was significantly higher in the follow-up than in the initial examinations (P=0.043). CONCLUSIONS: After observation for an average of 3 years and 3 months, most of the HIZ lesions in the lumbar intervertebral discs of the patients with low back pain remained stable in shape, but their signal intensity on MR images increased.

The association of high-intensity zones on MRI and low back pain: a systematic review.

BACKGROUND: Magnetic resonance imaging (MRI) of the lumbar spine is commonly used to identify the source of low back pain (LBP); however, its use has been questionable. Throughout the years, numerous lumbar phenotypes (e.g., endplate abnormalities, Modic changes, black disc) have been studied as possible pain generators. High-intensity zones (HIZs) are of particular interest as they may represent annular tears. However, for over three decades, there has been heated debate as to whether these imaging biomarkers are synonymous with LBP. Therefore, the following study addressed a systematic review of the reported literature addressing the relationship of HIZs and LBP. METHODS: A systematic review was conducted via MEDLINE, SCOPUS, Cochrane, PubMed, PubMed Central, EMBASE via Ovid, and Web of Science with the following search terms: "HIZ," "high intensity zone," or "high intensity zones" and "low back pain," "pain," "lumbago," and/or "sciatica." Specific exclusion criteria were also maintained. Two independent reviewers searched the literature, selected the studies, and extracted the data. RESULTS: We identified six studies from our search strategy that met the inclusion criteria from a total of 756 possible studies. One cross-sectional population-based study and five comparison studies were identified, which provided information regarding the prevalence of HIZs. The prevalence of HIZs was 3 to 61% in subjects with LBP and 2 to 3% in subjects without LBP. Only three studies suggested a significant association between the presence of HIZ and LBP with or without sciatica. CONCLUSIONS: Our systematic review has found evidence that HIZs may be a possible risk factor for LBP; however, a mismatch of the clinical relevance of HIZs between studies still remains. The available evidence is limited by small sample size, heterogeneous study populations, and lack of standardized imaging methods for phenotyping. HIZs may be important lumbar biomarkers that demand further investigation and should be considered in the global imaging assessment of the spine, which may have immense clinical utility. Further large-scale studies with standardized imaging and classification techniques as well as the assessment of patterns of HIZs are necessary to better understand their role with LBP development.

Treatment of Low Back Pain by Treating the Annular High Intensity Zone (HIZ) Lesions Using Percutaneous Transforaminal Endoscopic Disc Surgery.

BACKGROUND: The study design was a retrospective case series. The objective was to find the clinical success rate of percutaneous transforaminal endoscopic disc surgery in patients suffering from discogenic chronic low back pain who were showing high intensity zone (HIZ) with degenerated disc as the only abnormality in the magnetic resonance imaging (MRI). The HIZ in the posterior annulus in degenerated disc is recognized as a pain generator. There are only a few studies available in the literature addressing the effect of identification and treatment of HIZ in the chronic low back pain patient. METHODS: We retrospectively evaluated the case records of all the patients who were treated by percutaneous endoscopic disc surgery for relief of symptoms as determined by visual analog scale (VAS) score, Oswestry Disability Index (ODI), Mac Nab criteria, and the consumption of analgesics, who had the predominant symptom of chronic low back pain, and whose lumbar spine MRI showed degenerated disc with HIZ and no other cause of back pain, like facet joint arthritis or sacroiliac joint arthritis. RESULTS: A total of 23 patients were identified to include in the study. Mean preoperative duration of low back pain was 13.1 months. Mean follow up after the procedure was 29 months. At final follow up, 69.6% of the patients were not taking any pain medicines, 17.36% were on frequent analgesic medicines, 13.04% were on occasional analgesics. There was statistically significant reduction in VAS at 6 weeks postop and final follow up after surgery and the ODI at final follow up; 82.6% of patients had an excellent/good outcome as per Mac Nab criteria. There were no complications or reoperations in any of the patients. CONCLUSIONS: Visualization and ablation of the chronic annular pathology in HIZ may give an effective and minimally invasive treatment for one of the back pain causes.

Prevalence of High-Intensity Zones in the Lumbar Spine According to Age and Their Correlation with Other Degenerative Findings on Magnetic Resonance Imaging.

INTRODUCTION: A high-intensity zone (HIZ) in an intervertebral disc of the lumbar spine is a high-intensity signal located in the posterior annulus fibrosus on T2-weighted magnetic resonance imaging (MRI). There is limited information on the prevalence of HIZ in the lumbar spine according to age. The aim of this cross-sectional study was to investigate the prevalence of HIZ in the lumbar spine by age and the correlation between HIZ and other degenerative findings, such as disc degeneration, disc bulging and herniation, and changes in adjacent vertebral endplates on lumbar MRI. METHODS: We retrospectively reviewed MRI studies of 305 patients (1525 discs) with low back pain, leg pain, or numbness. The prevalence of HIZ was calculated in 5 age groups (<20, 20-39, 40-59, 60-79, 80-91 years). RESULTS: The number of patients in the 5 age groups was 19, 38, 69, 145, and 36, respectively. The prevalence of HIZ in the 5 age groups was 11.8%, 47.3%, 52.2%, 42.8%, and 50.0%, respectively. Disc degeneration was observed in 58.1% and 39.2% of discs with and without HIZ, respectively; disc bulging and herniation was observed in 63.9% and 41.1% and intensity changes at adjacent end plates in 11.6% and 10.0%, respectively. CONCLUSIONS: Prevalence of HIZ from the third decade of life onward was around 50%, with no significant change in prevalence beyond the age of 20 years. HIZ was correlated with disc degeneration, disc bulging, and disc herniation in patients with LBP, leg pain, or numbness.

Changes in shape and signal intensity of high intensity zone in lumbar intervertebral discs on magnetic resonance images: a longitudinal study / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate changes over time in the shape and signal intensity of high intensity zone (HIZ) in the lumbar intervertebral discs on magnetic resonance images in patients with low back pain.</p><p><b>METHODS</b>The imaging data were collected from 27 patients with low back pain, who underwent lumbar magnetic resonance (MR) imaging examinations that identified HIZ lesions and received follow-up MR examinations at least 1.5 years later over the period from January 2009 to January 2017. The initial and follow-up MR T2WI images of the patients were read by two experienced radiologists to categorize the changes in the shape of the HIZ lesions into enlarged, unchanged, shrunk, and disappeared. The volume and signal/cerebrospinal fluid signal intensity (T2/CSF) ratio of the HIZ were measured on sagittal MR images using ImageJ software.</p><p><b>RESULTS</b>Of the 43 HIZ lesions found in the initial examinations, 22 (51.2%) remained unchanged in the follow-up examinations, 10 (21.3%) were enlarged, 9 (20.9%) shrank, and 2 (23.3%) disappeared. The follow-up examinations revealed 4 new HIZ lesions in the intervertebral discs. The volumes of these lesions did not vary significantly in the follow-up examinations (=0.653), but the T2/CSF ratio was significantly higher in the follow-up than in the initial examinations (=0.043).</p><p><b>CONCLUSIONS</b>After observation for an average of 3 years and 3 months, most of the HIZ lesions in the lumbar intervertebral discs of the patients with low back pain remained stable in shape, but their signal intensity on MR images increased.</p>

The correlation between the high-intensity zone on a T2-weighted MRI and positive outcomes of discography: a meta-analysis.

BACKGROUND: This meta-analysis aimed to assess the correlation between the high-intensity zone (HIZ) of a lumbar MRI and discography. METHODS: We conducted an electronic search of the PubMed, MEDLINE, Embase, and ScienceDirect databases from their respective inceptions to October 2016 using the following search terms: "low back pain," "discogenic low back pain," "HIZ or high-intensity zone," and "discography". Relevant journals and conference proceedings were manually searched. Two reviewers independently assessed the quality of the studies, extracted data from the included studies, and analyzed the data. RESULTS: Eleven studies were included. The results of the meta-analysis indicated that outstanding relativity and statistically significant correlations were observed between the HIZ and abnormal disc morphology (OR = 47.79; 95% CI: 17.07 to 133.77; P < 0.00001), HIZ and pain reproduction (OR = 8.65, 95% CI: 6.01 to 15.23, P < 0.00001), and HIZ and abnormal morphology pain reproduction (OR = 11.74, 95% CI: 1.99 to 69.36, P = 0.007). CONCLUSIONS: The presence of an HIZ on a lumbar MRI T2-weighted image indicates abnormal disc morphology. There is a strong relationship between the HIZ and pain reproduction. The HIZ can be an effective index for prediction of discogenic low back pain.

The relationship between findings on magnetic resonance imaging and previous history of low back pain.

The objective of this study was to evaluate the relationship between magnetic resonance imaging (MRI) findings and previous low back pain (LBP) in participants without current LBP. Current LBP was defined as LBP during the past month. Previous LBP was defined as a history of medical consultation for LBP. Ninety-one participants without current LBP were included. Sagittal T2-weighted MRI was used to assess the intervertebral space from T12/L1 to L5/S1. These images were classified into five grades based on the Pfirrmann grading system. Furthermore, we evaluated the presence of disk bulging, high-intensity zone, and spondylolisthesis. We compared the MRI findings between groups with (27 participants) and without (64 participants) previous LBP without current LBP. Intraobserver and interobserver kappa values were evaluated. Participants had an average age of 34.9 years; 47 were female and 44 were male; and their average body mass index was 21.8 kg/m2. Compared to the group of participants without previous LBP, the group of participants with previous LBP had a significantly higher incidence of disk degeneration such as a Pfirrmann grade ≥3, disk bulging, and high-intensity zone in the analyses adjusted by age and sex. There were no significant differences in spondylolisthesis between the groups. An odds ratio of >10 was only found for Pfirrmann grade ≥3, ie, a Pfirrmann grade ≥3 was strongly associated with a history of previous LBP in participants without current LBP.