Magnetic resonance imaging in the evaluation of the lumbar herniated intervertebral disc

Differential diagnosis between recurrent disc herniation and granulation tissue after lumbar disc herniation Surgery: Qualitative analysis on MRI scans

BACKGROUND

Recurrence of disc herniation is a prevalent late-term complication among patients surgically treated for lumbar disc herniation. Differential diagnosis between recurrent disc herniation and granulation tissue can be achieved through signal intensity measurements on T2-weighted MRI examinations. This study aims to examine cases operated on for recurrence of lumbar disc herniation, assessing those presenting with either disc recurrence or granulation tissue. The objective is to demonstrate that differential diagnosis can be facilitated through signal intensity value measurements and radiological findings in MRI examinations of patients with disc herniation recurrence and granulation tissue.

METHODS

Analysis involved reviewing lumbar MRI T2 sequences of patients operated on with a presumptive diagnosis of lumbar disc herniation recurrence. Mean T2 signal intensity values in preoperative MRI images of cases with disc herniation recurrence and granulation tissue were examined and recorded on the Picture Archiving and Communication System. Mean T2 signal intensity values of recurrent disc herniation and granulation tissue were then compared.

RESULTS

Among the patients who underwent surgery, disc herniation recurrence was observed in 135 cases, while granulation tissue was found in 12 patients (8.89 %). The preopreative mean T2 signal intensity value for disc herniation was recorded as 54.82 ± 2.42, whereas the mean T2 signal intensity value for granulation tissue was 205.96 ± 5.62.

CONCLUSIONS

T2 sequences in MRI examinations offer the clearest evaluation of disc herniations. Mean T2 signal intensity value measurements conducted on the PACS system can aid in differentiating between recurrent disc herniation and granulation tissue. These findings serve to inform surgical protocols during the preoperative phase.

Lumbar disc herniation: Epidemiology, clinical and radiologic diagnosis WFNS spine committee recommendations

Objective

To formulate the most current, evidence-based recommendations regarding the epidemiology, clinical diagnosis, and radiographic diagnosis of lumbar herniated disk (LDH).

Methods

A systematic literature search in PubMed, MEDLINE, and CENTRAL was performed from 2012 to 2022 using the search terms "herniated lumbar disc", "epidemiology", "prevention" "clinical diagnosis", and "radiological diagnosis". Screening criteria resulted in 17, 16, and 90 studies respectively that were analyzed regarding epidemiology, clinical diagnosis, and radiographic diagnosis of LDH. Using the Delphi method and two rounds of voting at two separate international meetings, ten members of the WFNS (World Federation of Neurosurgical Societies) Spine Committee generated eleven final consensus statements.

Results

The lifetime risk for symptomatic LDH is 1-3%; of these, 60-90% resolve spontaneously. Risk factors for LDH include genetic and environmental factors, strenuous activity, and smoking. LDH is more common in males and in 30-50 year olds. A set of clinical tests, including manual muscle testing, sensory testing, Lasegue sign, and crossed Lasegue sign are recommended to diagnose LDH. Magnetic resonance imaging (MRI) is the gold standard for confirming suspected LDH.

Conclusions

These eleven final consensus statements provide current, evidence-based guidelines on the epidemiology, clinical diagnosis, and radiographic diagnosis of LDH for practicing spine surgeons worldwide.

Spontaneous epidural and subdural hematomas of the spine: Review of anatomy and imaging findings

Spontaneous epidural (SEH) and subdural hematomas (SSH) of the spine are a rare cause of spinal injury and morbidity. They often present in the emergency setting, though magnetic resonance imaging is the gold-standard for diagnosis. Knowledge of anatomy, and in particular of the dural layers of the spine, is crucial to understand the location of SEH and SSH and their relationship with spinal structure. In this pictorial review, we aim to explain imaging features of the SEH and SSH, and to rule out their main differential diagnosis.

Clinical Reporting of Magnetic Resonance Imaging, the Way Forward for Patients With Lumbar Disc Herniation: A Prospective Correlational Study

Background

Lower back pain (LBP) is a major cause of increasing years lived with disability. Many adults suffer from LBP once in their lifetime. Multiple environmental, genetic, and acquired factors lead to disc degeneration. Spinal stenosis can be caused due to bony, ligamentous, or discogenic origin. The majority of cases have a combined etiology of bony, ligamentous, and disc disease. Lumbar disc disease (LDD) has been mentioned by various terminologies in the literature. A standardized nomenclature is needed for better research and communication. Our study is based on the correlation between lumbar disc herniation (LDH) and magnetic resonance imaging (MRI) findings.

Methodology

A prospective observational study was undertaken on patients presenting with signs and symptoms suggestive of LDD to the Department of Orthopaedics at a tertiary care hospital in southern Rajasthan. The purposive sampling technique with a consecutive scheme was used. MRI is a valuable tool for diagnosing LDH.

Results

Many studies have concluded false-positive results for MRI in cases of LDH. Hence, interpretation with grading systems (Pfirrmann’s and Scizas grading) and correlation with clinical findings are mandatory for accurate diagnosis and management of patients.

Conclusions

We suggest clinicians adopt clinical reporting of MRI to improve the diagnostic accuracy with clinical and radiological correlation. Reporting can guide professionals in deciding the course of treatment in the form of conservative or surgical management.

RELIABILITY OF THE MICHIGAN STATE UNIVERSITY (MSU) CLASSIFICATION OF LUMBAR DISC HERNIATION

Objective:

The Michigan State University (MSU) classification of lumbar disc herniation (LDH) is periodically used by various authors to classify disc herniation. We assessed the reliability of this classification system among orthopedic residents at our institute.

Methods:

Fifty T2 axial-cut magnetic resonance images (MRI) corresponding to the level of maximal disc herniation from patients diagnosed with a single LDH were selected and distributed to six orthopedic residents. All six residents gave a specific rating for each image based on the MSU classification; in addition, three residents gave ratings on two different occasions. The degree of agreement among residents was analyzed by calculating inter-observer and intra-observer reliability using the Kappa statistic.

Results:

The inter-observer reliability among the six residents calculated as the Fleiss’ Kappa was 0.422, which indicates moderate reliability. The intra-observer reliability of three selected residents calculated by Cohen's Kappa was 0.750, 0.772, and 0.859, which indicates substantial to almost perfect reliability. Variations in ratings were frequent in images portraying a broad-based disc herniation with spinal canal stenosis.

Conclusion:

Our findings demonstrate moderate homogeneity of ratings given by residents; however, test-retest results proved the ratings to be consistent. Level of Evidence II, Diagnostic studies - investigating a diagnostic examination.

Lumbar Disc Herniation

PURPOSE OF REVIEW

Substantial advancements have been made in the cause, diagnosis, imaging, and treatment options available for patients with lumbar disc herniation (LDH). We examined the current evidence and highlight the concepts on the frontline of discovery in LDH.

RECENT FINDINGS

There are a myriad of novel etiologies of LDH detailed in recent literature including inflammatory factors and infectious microbes. In the clinical setting, recent data focuses on improvements in computer tomography as a diagnostic tool and non-traditional injection options including tumor necrosis alpha inhibitors and platelet-rich plasma. Operative treatment outcomes have focused on minimally invasive endoscopic approaches and demonstrated robust 5-year post-operative outcomes. Advances in the molecular etiology of LDH will continue to drive novel treatment options. The role of endoscopic treatment for LDH will continue to evolve. Further research into10-year outcomes will be necessary as this surgical approach continues to gain widespread popularity.

Diagnostic accuracy of standardised qualitative sensory test in the detection of lumbar lateral stenosis involving the L5 nerve root

Misdiagnosis of symptomatic lumbar lateral stenosis (LS) may result in an unfavourable prognosis after surgical treatment. This study investigated the diagnostic accuracy of a standardised qualitative sensory test (SQST) in the detection of symptomatic LS in patients who had degenerative spinal disorders involving the L5 spinal nerve. We prospectively identified 75 patients, of which 60 met the inclusion criteria. Lateral recess stenosis at the L5 level or foraminal stenosis at the L5/S1 level on MRI was identified and graded by a neurosurgeon blinded to any clinical information. The reference criteria for the diagnosis of symptomatic LS were grade III LS on MRI and relevant clinical symptoms. Cutaneous sensory functions of the L5 dermatome on the symptomatic side were evaluated using the SQST. Each item of the SQST showed a satisfactory performance in the diagnosis of LS (sensitivity = 0.455-0.727, specificity = 0.868-1.0). A stepwise selection model identified low-strength von-Frey, high-strength von-Frey, and vibration as the most accurate predictors of symptomatic LS with an area under the receiver operating characteristic curve of 0.9563 (95% confidence interval = 0.9003-1.0). In combination with MRI, the SQST is a promising diagnostic tool for detecting symptomatic LS involving L5 nerve roots.

Combination of Magnetic Resonance Imaging and Electrophysiological Studies in Lumbar Disc Herniation

Objective We aimed to study the clinical value of magnetic resonance imaging (MRI) and electrophysiological studies in the diagnosis of lumbar disc herniation and in the evaluation of the therapeutic effect of discectomy. Methods In this study, 265 patients with LDH were treated with discectomy after assessment by the Japanese Orthopedic Association (JOA) score, MRI, and electrophysiological studies. All the patients were followed-up for 6 years. The effects of the operation were assessed by determining the angle between the nerve root canal and disc protrusion (AN value), the stenotic ratio of the spinal canal, the width of the lateral recess, motor conduction velocity (MCV), sensory conduction velocity (SCV), and nerve action potential (NAP) before and after operation. Results The AN value, stenotic ratio of the spinal canal, and the width of the lateral recess of protruding intervertebral discs showed significant differences from these values for the patients' unaffected intervertebral discs (P < 0.05). The MCV, SCV, and NAP of the affected limb showed significant differences from these values for the patients' unaffected limbs (P < 0.05). In all the patients the values for these indicators showed significant differences before and after operation (P < 0.05). Conclusion MRI and electrophysiological studies can be used in the diagnosis of lumbar disc herniation, and in the evaluation of the effect of surgery.

The Association Between Modic Changes of Lumbar Endplates and Spontaneous Absorption of Herniated Intervertebral Discs

Herniated disc (HD) is one of the most common causes of lower back pain. Treatment for HD includes conservative therapy and surgical intervention. Following conservative treatment, spontaneous absorption of HD occurs in some patients. To assess whether modic changes are associated with spontaneous absorption of HD, 85 patients with or without modic changes were followed up after 6 months of conservative treatment. As result, we found modic changes of lumbar endplates are associated with poor absorption of HD after conservative treatment. In addition, patients with modic changes exhibit significantly increased cartilage content and decreased neovascularization and macrophage infiltration in HD tissues, all of which are known to impair spontaneous absorption of herniated tissues. At molecular level, modic changes are associated with decreased expression of matrix metalloproteinase-3 gene, which is a key matrix-degrading enzyme for tissue absorption. Our study established a strong association between modic changes of lumbar endplates and spontaneous absorption of lumbar HD, which provided a potential novel method for prediction of spontaneous absorption.

Disc herniation diagnosis in MRI using a CAD framework and a two-level classifier

PURPOSE

Disc herniation in the lumbar spine is a common condition, so an automated method for diagnosis could be helpful in clinical applications. A computer-aided framework for disk herniation diagnosis was developed for use in magnetic resonance imaging (MRI).

MATERIALS AND METHOD

A computer-aided diagnosis framework for lumbar spine with a two-level classification scheme for disc herniation diagnosis was developed using heterogeneous classifiers: a perceptron classifier, a least mean square classifier, a support vector machine classifier, and a k-Means classifier. Each classifier makes a diagnosis based on a feature set generated from regions of interest that contain vertebrae, a disc, and the spinal cord. Then, an ensemble classifier makes a final decision using score values of each classifier. We used clinical MR image data from 70 subjects in T1-weighted sagittal view and T2-weighted sagittal view for evaluation of the system.

RESULTS

MR images of 70 subjects were processed using the proposed framework resulting in successful detection of disc herniation with 99% accuracy, achieving a speedup factor of 30 in comparison with radiologist's diagnosis.

CONCLUSION

The computer-aided framework works well to diagnose herniated discs in MRI scans. We expect the framework can be adapted to effectively diagnose a variety of abnormalities in the lumbar spine.

The accuracy of MRI in the detection of lumbar disc containment

BACKGROUND

MRI has proven to be an extremely valuable tool in the assessment of normal and pathological spinal anatomy. Accordingly, it is commonly used to assess containment of discal material by the outer fibers of the anulus fibrosus and posterior longitudinal ligaments. Determination of such containment is important to determine candidacy for intradiscal techniques and has prognostic significance. The accuracy of MRI in detecting containment has been insufficiently documented.

METHODS

The MRI's of fifty consecutive patients undergoing open lumbar microdiscectomy were prospectively evaluated for disc containment by a neuroradiologist and senior spinal surgeon using criteria available in the literature and the classification of Macnab/McCulloch. An independent surgeon then performed the surgery and documented the actual containment status using the same methods. Statistical evaluation of accuracy was undertaken.

RESULTS

MRI was found to be 72% sensitive, 68% specific, and 70% accurate in detecting containment status of lumbar herniated discs.

CONCLUSION

MRI may be inaccurate in assessing containment status of lumbar disc herniations in 30% of cases. Given the importance of containment for patient selection for indirect discectomy techniques and intradiscal therapies, coupled with prognostic significance; other methods to assess containment should be employed to assess containment when such alternative interventions are being considered.

Dorsal Extradural Thoracic Disc Fragment

Dorsal epidural migration of an extruded disc fragment is an infrequent event, especially in the thoracic spine. An uncommon case involving a 55-year-old man is presented, with a 1-month history of paraparesis and thoracolumbar pain. Magnetic resonance imaging demonstrated a dorsally located, extramedullary mass at the T10-T11 intervertebral level. The lesion was suspected to be a tumor. The patient underwent a T10-T11 laminectomy. Intraoperatively, an encapsulated mass of soft tissue adherent to the dural sac was found. The pathologic diagnosis was inflammatory tissue and disc material. Six months after the operation, the patient remained asymptomatic, and radiologic control showed no residual mass. Although rare, a sequestered disc fragment should be included in the differential diagnosis of an enhancing posterior extramedullary thoracic mass. Preoperative diagnosis of such pathology is difficult because the clinical signs and radiologic images may not entirely exclude other more common thoracic spinal lesions, especially tumors.

Anatomic and clinical investigation of a low signal peripheral line (black line) around the lumbar herniated nucleus pulposus on magnetic resonance imaging

It has been reported that a low signal peripheral line (black line) around the lumbar herniated nucleus pulposus (HNP) on magnetic resonance imaging (MRI) can be used for the evaluation of the interruption of the posterior longitudinal ligament (PLL). However, the previous reports have showed that different rates of agreement between MRI and surgical findings. In order to clarify this matter, the black line on MRI was assessed by a combined anatomic and clinical investigation. Three cadavers were used for the anatomic part of the study. For the clinical study, 11 patients with the diagnosis as HNP and 5 healthy volunteers were subjected to MRI to compare with the results from the anatomic study. The lumbo-sacral spine was dissected en bloc from the cadavers. The first imaging on MRI of the specimens was performed with the dural sac; the second imaging was performed after the dural sac and the nerve roots have been removed but with the PLL left; the third imaging was performed after the PLL was completely removed. After completion of imaging, the specimens were cut in sagittal and horizontal planes for histological evaluation. In the cadavers after removing the PLL histologically, the black lines were still shown on MRI. Finally, after changing encoding, the black lines were interrupted at some disc levels in the cadaver specimen, the patients with HNP, and healthy volunteers. Therefore the black lines could be interpreted as a chemical shift artifact. These results indicate that the continuity or the discontinuity of the black line is not appropriate sign to diagnose whether disruption of the PLL has occurred or not.

Posterior disk displacement: morphologic assessment and measurement reliability-lumbar spine

BACKGROUND

Magnetic resonance imaging is often used to assess for disk displacement after manipulation, but limited information about the true incidence of iatrogenic herniations exists. To design a study that evaluates for a causal relationship, preliminary data must be obtained relating to the size of different types of disk displacement. The reliability of chiropractic radiologists in assessing disks and a comparison of different measuring devices should also be evaluated.

OBJECTIVE

To identify average measurements for normal and displaced disks and to assess the reliability of measurements by chiropractic radiologists.

STUDY DESIGN

Intraobserver and interobserver reliability study assessing disk displacement on magnetic resonance scans.

METHODS

Three evaluators assessed the disks on 122 magnetic resonance scans from two imaging centers. Six categories were graded, and digitizer and ruler measurements were compared. Forty-four scans were reassessed for intraobserver agreement. Intraobserver and interobserver variations were measured with intraclass correlation coefficient and kappa statistical analysis. Measurement device correlation was assessed with Pearson's r.

RESULTS

Clear size differences between different types of disk displacement were noted. Interexaminer measurement reliability was 0.78 to 0.84. Agreement concerning the presence of disk displacement was 85% (kappa = 0.68), and the classification of disk displacements was 76% (kappa = 0.60). Intraexaminer measurement reliability was 0.40 to 0.49. Intraexaminer agreement concerning the presence of disk displacement was 76% (kappa = 0.52), and the classification of disk displacements was 62% to 69% (kappa = 0.38 to 0.46). Normal versus bulged disk distinctions demonstrated the most disagreement. The ruler and digitizer correlation coefficient was 0.968.

CONCLUSIONS

Different disk types demonstrated distinct size averages. Interexaminer agreement was good concerning disk assessment and measurements. Intraexaminer agreement was lower than expected. A millimetric ruler is an acceptable alternative to digital measurement devices.

Lumbar herniated disks

Patients with low back and leg pain require careful evaluation and it is essential that there is correlation between the symptoms and signs of sciatica and the imaging demonstration of nerve root compression or displacement by a disk herniation before invasive therapy is undertaken. The natural history of herniations of the nucleus pulposus is complex and the relationship between the appearances on imaging and low back and radicular pain still has to be completely resolved. Considerable experimental work has been undertaken on the relationship between nerve compression, inflammation, and pain and recent studies on cytokines may lead to more precise pharmacologic therapies. The prime value of MR imaging may be in monitoring disk and nerve root changes in longitudinal studies of patients randomized to different therapeutic programs.

MRI of the lumbar intervertebral disc

The lumbar spine is one of the commonest regions of the body imaged with MRI. Various pathological processes can involve the lumbar intervertebral disc, including degeneration, infection and trauma and these may present with a variety of signal intensity and morphological changes as depicted by MRI. The aim of this pictorial review is to illustrate these abnormalities and discuss their clinical relevance where appropriate.