Myelography

Fluoroscopic, Computed Tomographic, and Magnetic Resonance Myelography

Despite all the advantages of magnetic resonance (MR) imaging, there still exist contraindications or limitations to its use. Thus, MR imaging has not entirely replaced fluoroscopic or computed tomographic (CT) myelography to depict the outline of the spinal cord and its nerve roots after intrathecal injection of contrast medium. The growing recent interest of neuroradiologists to accurately diagnose and treat cerebrospinal fluid leaks has also driven a resurgent need for familiarity with this image-guided procedure. This article reviews the numerous technical and periprocedural aspects of fluoroscopic and CT myelography, and the use of noninvasive MR myelography in certain clinical scenarios.

Tube current reduction and iterative image reconstruction for computed tomography myelography

This study aimed to systematically evaluate the impact of a low-dose (LD) protocol using tube current reduction on image quality, the confidence for intervention planning and guidance, and diagnostic yield for computed tomography (CT) myelography. We retrospectively analyzed 68 patients who underwent CT myelography, with 34 investigations performed with a standard-dose (SD) and 34 investigations performed with a LD protocol (using tube current reduction). The different scans were matched considering variables such as sex, age, presence of spinal instrumentation, and body diameter. All images were evaluated by two readers (R1 and R2) using Likert scales. Image noise was measured using attenuation values of paraspinal muscle tissue. Images were reconstructed with model-based iterative reconstruction (post-myelography diagnostic scans) or hybrid reconstruction (planning, periprocedural, and diagnostic scans). Image quality, overall artifacts, image contrast, and confidence for planning or intervention guidance were rated good to perfect for both SD and LD scans according to evaluations of both readers. Inter-reader agreement was good to very good for the images from intervention planning (κ ≥ 0.80) as well as for intervention guidance (κ ≥ 0.77), as well as for diagnostic scans (κ ≥ 0.85). Image noise was similar between SD and LD scans performed for planning of the interventional procedures (model-based iterative reconstruction: SD 45.37 ± 7.29 HU vs. LD 45.17 ± 9.12 HU; hybrid reconstruction: SD 46.05 ± 7.43 HU vs. LD 45.05 ± 8.69 HU; p > 0.05). The volume-weighted CT dose index (CTDIvol) and size-specific dose estimate (SSDE) were significantly lower for the planning scans as well as the periprocedural scans when using the LD protocol as compared to the SD protocol (p < 0.05). In conclusion, implementation of a LD protocol with tube current reduction for CT myelography is a feasible option to reduce radiation exposure, especially when combined with iterative image reconstruction. In our study, LD imaging did not have a relevant negative impact on image quality, confidence for intervention planning or guidance, or diagnostic certainty for CT myelography.

Impact of computed tomography/magnetic resonance imaging registration on rehabilitation after percutaneous endoscopic decompression for lumbar stenosis: Retrospective study

BACKGROUND

Percutaneous endoscopic lumbar decompression (PELD) shows promise for lumbar spinal stenosis (LSS) treatment, but its use is limited by the disease's complexity and procedural challenges.

AIM

In this study, the effects of preoperative planning and intraoperative guidance with computed tomography (CT)/magnetic resonance imaging (MRI) registration techniques on PELD for LSS and postoperative rehabilitation outcomes were evaluated.

METHODS

This retrospective study was conducted with data from patients who underwent PELD for LSS between January 2021 and December 2023. Patients were assigned to preoperative CT/MRI registration and control groups. Data collected included the operative time, length of hospital stay, visual analog scale (VAS) scores for low back and leg pain, and the Japanese Orthopaedic Association (JOA) lumbar spine score. Differences between groups were assessed using Student’s t test.

RESULTS

Data from 135 patients (71 in the CT/MRI registration group, 64 in the control group) were analyzed. The operative time was significantly shorter in the CT/MRI registration group (P = 0.007). At 2 months postoperatively, both groups showed significant reductions in VAS leg and low back pain scores (all P < 0.001) and improvements in the JOA score (both P < 0.001). No complication or death occurred. Preoperatively, pain and JOA scores were similar between groups (P = 0.830, P = 0.470, and P = 0.287, respectively). At 2 months postoperatively, patients in the CT/MRI registration group reported lower leg and low back pain levels (P < 0.001 and P = 0.001, respectively) and had higher JOA scores (P = 0.004) than did patients in the control group.

CONCLUSION

Preoperative CT/MRI registration for PELD for LSS reduced the operative time and VAS pain scores at 2 months and improved JOA scores, demonstrating enhanced effectiveness and safety.

Preoperative application of CT and MRI registration in lumbar disc herniation endoscopic surgery could improve the postoperative rehabilitation of patients

BACKGROUND

Percutaneous Endoscopic Lumbar Discectomy (PELD) has emerged as routine treatment for lumbar disc herniation (LDH) due to its minimal invasiveness and quick recovery. However, PELD demands high precision from the surgeon, as the risk of intraoperative complications is substantial, including potential damage to the nerve root and dura, and a higher likelihood of recurrence post-surgery. Thus, preoperative planning utilizing CT and MRI imaging is essential.

METHODS

In this study, the clinical data of 140 patients treated with PELD for LDH from January 2021 to December 2023 were retrospectively analyzed. Patients were categorized into two groups based on whether CT and MRI registration (CMR) was employed for surgical planning: a CMR group (n=68) and a control group (n=72). Data collected included surgery time, hospital stay duration, and scores from the Visual Analog Scale (VAS) for low back and leg pain, as well as the Japanese Orthopaedic Association Lumbar Spine Score (JOA). Differences between the two groups were assessed using the Student's t-test.

RESULTS

No significant difference was found in hospital stay length between the groups (P=0.277). Surgery time was significantly shorter in the CMR group (P<0.001). Prior to surgery, no significant differences in VAS scores for leg and low back pain were observed between the groups (P=0.341 and P=0.131, respectively); however, at 2 months postoperatively, both scores were significantly lower in the CMR group (P<0.001 and P=0.002, respectively). Similarly, no difference in preoperative JOA scores was noted (P=0.750), but at 2 months postoperative, the CMR group exhibited significantly higher scores (P<0.001).

CONCLUSION

Compared with the traditional PELD, the preoperative use of CMR has shown to reduce surgery time, alleviate leg and low back pain, and increase the lumbar JOA score at 2 months after surgery, underscoring its efficacy in enhancing surgical outcomes.

The Role of Magnetic Resonance Imaging and Computed Tomography in Spinal Cord Injury

Traumatic injuries of the spine are associated with long-term morbidity and mortality. Timely diagnosis and appropriate management of mechanical instability and spinal cord injury are important to prevent further neurologic deterioration. Spine surgeons require an understanding of the essential imaging techniques concerning the diagnosis, management, and prognosis of spinal cord injury. We present a review in the role of computed tomography (CT) including advancements in multidetector CT (MDCT), dual energy CT (DECT), and photon counting CT, and how it relates to spinal trauma. We also review magnetic resonance imaging (MRI) and some of the developed MRI based classifications for prognosticating the severity and outcome of spinal cord injury, such as diffusion weighted imaging (DWI), diffusion tractography (DTI), functional MRI (fMRI), and perfusion MRI.

Value of imaging examinations in diagnosing lumbar disc herniation: A systematic review and meta-analysis

Purpose

To systematically review the clinical value of three imaging examinations (Magnetic Resonance Imaging, Computed Tomography, and myelography) in the diagnosis of Lumbar Disc Herniation.

Methods

Databases including PubMed, Embase, The Cochrane Library, Web of Science, CBM, CNKI, WanFang Data, and VIP were electronically searched to collect relevant studies on three imaging examinations in the diagnosis of Lumbar Disc Herniation from inception to July 1, 2021. Two reviewers using the Quality Assessment of Diagnostic Accuracy Studies-2 tool independently screened the literature, extracted the data, and assessed the risk of bias of included studies. Then, meta-analysis was performed by using Meta-DiSc 1.4 software and Stata 15.0 software.

Results

A total of 38 studies from 19 articles were included, involving 1,875 patients. The results showed that the pooled Sensitivity, pooled Specificity, pooled Positive Likelihood Ratio, pooled Negative Likelihood Ratio, pooled Diagnostic Odds Ratio, Area Under the Curve of Summary Receiver Operating Characteristic, and Q* were 0.89 (95%CI: 0.87-0.91), 0.83 (95%CI: 0.78-0.87), 4.57 (95%CI: 2.95-7.08), 0.14 (95%CI: 0.09-0.22), 39.80 (95%CI: 18.35-86.32), 0.934, and 0.870, respectively, for Magnetic Resonance Imaging. The pooled Sensitivity, pooled Specificity, pooled Positive Likelihood Ratio, pooled Negative Likelihood Ratio, pooled Diagnostic Odds Ratio, Area Under the Curve of Summary Receiver Operating Characteristic, and Q* were 0.82 (95%CI: 0.79-0.85), 0.78 (95%CI: 0.73-0.82), 3.54 (95%CI: 2.86-4.39), 0.19 (95%CI: 0.12-0.30), 20.47 (95%CI: 10.31-40.65), 0.835, and 0.792, respectively, for Computed Tomography. The pooled Sensitivity, pooled Specificity, pooled Positive Likelihood Ratio, pooled Negative Likelihood Ratio, pooled Diagnostic Odds Ratio, Area Under the Curve of Summary Receiver Operating Characteristic, and Q* were 0.79 (95%CI: 0.75-0.82), 0.75 (95%CI: 0.70-0.80), 2.94 (95%CI: 2.43-3.56), 0.29 (95%CI: 0.21-0.42), 9.59 (95%CI: 7.05-13.04), 0.834, and 0.767 respectively, for myelography.

Conclusion

Three imaging examinations had high diagnostic value. In addition, compared with myelography, Magnetic Resonance Imaging had a higher diagnostic value.

Virtual CT Myelography: A Patch-Based Machine Learning Model to Improve Intraspinal Soft Tissue Visualization on Unenhanced Dual-Energy Lumbar Spine CT

Background: Distinguishing between the spinal cord and cerebrospinal fluid (CSF) non-invasively on CT is challenging due to their similar mass densities. We hypothesize that patch-based machine learning applied to dual-energy CT can accurately distinguish CSF from neural or other tissues based on the center voxel and neighboring voxels. Methods: 88 regions of interest (ROIs) from 12 patients’ dual-energy (100 and 140 kVp) lumbar spine CT exams were manually labeled by a neuroradiologist as one of 4 major tissue types (water, fat, bone, and nonspecific soft tissue). Four-class classifier convolutional neural networks were trained, validated, and tested on thousands of nonoverlapping patches extracted from 82 ROIs among 11 CT exams, with each patch representing pixel values (at low and high energies) of small, rectangular, 3D CT volumes. Different patch sizes were evaluated, ranging from 3 × 3 × 3 × 2 to 7 × 7 × 7 × 2. A final ensemble model incorporating all patch sizes was tested on patches extracted from six ROIs in a holdout patient. Results: Individual models showed overall test accuracies ranging from 99.8% for 3 × 3 × 3 × 2 patches (N = 19,423) to 98.1% for 7 × 7 × 7 × 2 patches (N = 1298). The final ensemble model showed 99.4% test classification accuracy, with sensitivities and specificities of 90% and 99.6%, respectively, for the water class and 98.6% and 100% for the soft tissue class. Conclusions: Convolutional neural networks utilizing local low-level features on dual-energy spine CT can yield accurate tissue classification and enhance the visualization of intraspinal neural tissue.

Single- and Dual-Source CT Myelography: Comparison of Radiation Exposure and Establishment of Diagnostic Reference Levels

CT myelography (CTM) is a diagnostic technique for the evaluation of various spinal pathologies, and plays an important role in diagnosis of different diseases such as spontaneous intracranial hypotension and postoperative cerebrospinal fluid leaks. The aims of this study were to examine radiation exposure, establish diagnostic reference levels (DRLs) and compare radiation doses of single- and dual-source examinations and different CTM protocols. In this retrospective study, 183 CTMs comprising 155 single-source and 28 dual-source examinations, performed between May 2015 and December 2020, were analyzed. Dose data included 31 whole spine (A), 23 cervical (B), 10 thoracic (C), and 119 lumbar (D) CTMs. Radiation exposure was reported for volume-weighted CT dose index (CTDI_vol) and dose-length product (DLP). Radiation doses for CTDI_vol and DLP were distributed as follows (median, IQR): A: 7.44 mGy (6.01–11.17 mGy)/509.7 mGy·cm (382.4–682.9 mGy·cm), B: 9.31 mGy (7.20–14.64 mGy)/214.5 mGy·cm (153.7–308.2 mGy·cm), C: 6.80 mGy (6.14–8.26 mGy)/365.4 mGy·cm (222.8–432.4 mGy·cm), D: 11.02 mGy (7.97–14.89 mGy)/308.0 mGy·cm (224.7–413.7 mGy·cm). Local DRLs could be depicted as follows (CTDI_vol/DLP): A: 11 mGy/683 mGy·cm, B: 15 mGy/308 mGy·cm, C: 8 mGy/432 mGy·cm, D: 15 mGy/414 mGy·cm. High image quality was achieved for all anatomical regions. Basically, radiation exposure of CTM differs according to anatomical location.

The Role and Contribution of Lumbar Myelography in the Diagnosis and Treatment of Patients With Lumbar Degenerative Disorders: Clinical and Statistical Evaluation of Post-Myelography Treatment of 63 Patients

Introduction

Myelography is a radiological examination method that has been used for the diagnosis of spinal canal pathologies for a long time. More than 90 years of experience has been improved by the development of increasingly less toxic contrast agents. Nowadays, although there are many advanced diagnostic tools, lumbar myelography is a direct imaging technique and so it is a powerful diagnostic method for patients whose treatment has not been decided. The aim of our study is to evaluate the effect of lumbar myelography as a diagnostic method and its contribution to treatment.

Materials and methods

Between January 2016 and April 2018, 63 patients who were admitted to our neurosurgery clinic due to lumbar degenerative disorders and underwent myelography were included in our study. Patients over 30 years of age with lumbar disc disease, narrow spinal canal, and spinal instability, but for whom a surgical decision could not be made, were included in this study.

Results

After lumbar myelography, 55 of 63 patients underwent a surgical procedure and 8 were directed to non-surgical treatment options. The results of the patients were evaluated by Roland-Morris Low Back Pain and Disability Questionnaire (RMQ). Results showed that the contribution of selected treatment protocols to the recovery after myelography was statistically significant.

Conclusion

Nowadays, myelography is not the first choice for the diagnosis of lumbar degenerative disorders. However, according to the results of our study, lumbar myelography is an effective diagnostic tool for specific purposes.

Persistence and regredience of intraspinal fluid collection determine symptom control in intracranial hypotension syndrome

Background and purpose

An intraspinal fluid collection (ISFC) can be observed on spinal MRI in cases of intracranial hypotension syndrome (IHS). The goal of this study was to analyze the possible persistence of ISFC after therapy and its correlation to clinical disease activity and secondary complications.

Materials and methods

Twenty patients in our database of 57 patients, who were treated for IHS between 2009 and 2015, fulfilled the inclusion criteria of (a) diagnosed and treated IHS as well as (b) an ISFC in MRI imaging. Ten of these participated in our study. We performed follow-up visits, which included a history, a clinical examination, and a spinal MRI.

Results

A MRI-confirmed ISFC was seen in six patients, five of which had symptoms attributable to chronic IHS. There were two cases of superficial siderosis. One patient had a persisting ISFC and was free of symptoms. Four patients did not have an ISFC and were free of symptoms (Fisher’s exact test; p < 0.048).

Conclusion

There is statistically significant correlation between the persistence of an ISFC after IHS treatment and ongoing clinical symptoms. Resolved symptoms seem to correlate with absorbed extradural ISFC and hypothetically closed leakage site. ISFC as confirmed by MRI proofs to be a reliable follow-up marker for disease activity in chronic IHS that is possibly even superior to clinical examination.

Formation of Adhesive Arachnoiditis with Epidural Fibrosis as a Cause of Repeated Surgical Interventions (Clinical Case)

The work presents a rare clinical case of adhesive arachnoiditis, which developed against the background of epidural fibrosis during repeated surgical interventions. The cicatricial adhesion in the epidural space is formed in 100% of cases after surgery and is a frequent cause of intraoperative complications during repeated surgical interventions (bleeding, damage to the spinal cord and the dura mater with subsequent outflow of cerebrospinal fluid) and, therefore, an unsatisfactory result of surgical treatment with the formation of constant pain of various intensity, pseudomeningocele, commissural arachnoiditis, etc. The cicatricial adhesion in the epidural space is the main reason for the development of failed back surgery syndrome (FBSS), which today is an important and unresolved problem in spinal surgery. The epidural, as well as the subdural and subarachnoid space of the operated spinal motor segment of the spinal canal can be involved in the cicatricial adhesion, as it is shown in our clinical example. In this regard, it is important to prevent the development of the cicatricial adhesion in the epidural space during primary spinal surgeries, since with the increase in life expectancy of the population and increase in surgical activity during spinal surgeries, the patient can be operated repeatedly. Consequently, the question arises of preventing the formation of the cicatricial adhesion in 100% of cases with each surgical intervention, since the formed cicatricial adhesion in the epidural space does not have effective methods of conservative and surgical treatment and worsens favorable and satisfactory forecasts of surgical treatment for repeated surgical interventions.

Recurrent arachnoid cysts secondary to spinal adhesive arachnoiditis successfully treated with a ventriculoperitoneal shunt

Spinal adhesive arachnoiditis (SAA) with cyst formation secondary to infectious meningitis is a rare clinical entity. These cysts can compress the spinal cord and cause neurologic decline. We present a case of a patient who underwent resection for an intradural schwannoma which was complicated post-operatively by bacterial meningitis and development of several recurrent thoracic arachnoid cysts. After two separate thoracic decompressions with lysis of intradural adhesions, a permanent ventriculoperitoneal shunt (VPS) was eventually placed with complete recovery of his symptoms. Our review of the literature showed that CSF shunts have previously been successfully used to treat spinal fluid collections. Although there are many factors to consider when treating these patients, CSF diversion may be beneficial for similar SAA presentations in order to simultaneously treat and prevent recurrence of symptoms.

Obstruction of Ventriculoperitoneal Shunt After Myelography-Report of a Unique Case and Its Treatment

BACKGROUND

Myelography, frequently supplanted by noninvasive, efficient magnetic resonance imaging, remains a useful technique when evaluating the spinal canal in nerve root avulsion, radiation therapy treatment planning, cerebrospinal fluid (CSF) loculation, and CSF leak. Myelography is achieved through a lumbar puncture and instillation of nonionic, water-soluble intrathecal iohexol (Omnipaque, GE Healthcare, Marlborough, Massachusetts, USA) contrast. The aim of the study was to highlight a possible complication of obstruction of a shunt valve due to an increased viscosity of the CSF after intrathecal Omnipaque contrast administration during myelography.

CASE DESCRIPTION

The authors report a case of myelography that resulted in obstruction of a ventriculoperitoneal (VP) shunt. A 23-year-old female with significant medical history of neurofibromatosis type I, obstructive hydrocephalus, anterior cervical diskectomy and fusion, and VP shunt placement underwent diagnostic computed tomography after myelography with Omnipaque contrast to assess possible CSF loculation and cord impingement from her cervical instrumentation. The patient experienced somnolence after myelography from obstruction of the VP shunt, with marked ventriculomegaly demonstrated by computed tomography of the head. A shunt tap and shunt pumping regimen resulted in resolution of the obstruction and hydrocephalus, with return to neurologic baseline.

CONCLUSIONS

This is a recent case of VP shunt obstruction after myelography, of which previous cases reported are decades old. A shunt pumping regimen may be a nonoperative, effective mean for similar mechanical obstructions of VP shunts for restoration of flow and patency of the shunt system in these patients. We encourage physicians to consider the possibility of shunt obstruction after diagnostic myelography. Caution and close observation should be considered in patients undergoing myelography with a programmable VP shunt.

Lumbar puncture under fluoroscopy guidance: a technical review for radiologists

There are many differences in fluoroscopy-guided lumbar puncture (FG-LP) technique among radiologists. Even within the same institution, there are a variety of preferences among proceduralists with individual perspectives based on the literature, training, and/or experience. Our aim is to provide familiarity with various techniques involved in FG-LP and provide insight on how to improve patient outcomes. The pertinent anatomy and physiology, indications, contraindications, patient management, complications of the procedure, and procedural techniques for performing an FG-LP are reviewed in detail. Potentially controversial topics regarding FG-LP are also addressed. There are many differences in fluoroscopy-guided lumbar puncture (FG-LP) technique among radiologists (1). Even within the same institution, there are a variety of individual preferences among physicians with different perspectives based on a combination of literature familiarity, training, and personal experience. Our aim is to provide familiarity with various techniques involved in FG-LP, improve efficiency, and improve patient outcomes. We will also address possible controversial issues regarding FG-LPs using an evidence-based approach.

Adhesive arachnoiditis following lumbar epidural steroid injections: a report of two cases and review of the literature

Lumbar epidural steroid injections (LESIs) are commonly used for managing lower back pain (LBP) and radicular pain. LESIs are generally considered safe with only rare serious complication. One very rare complication that is frequently cited in the literature is adhesive arachnoiditis. However, a literature search failed to detect even one published manuscript, clearly documenting LESI induced arachnoiditis. This article presents two patients who received a transforaminal L5–S1 and two L3–L4 interlaminar LESIs. Although the presented patients developed clear radiological (MRI) findings of arachnoiditis, they were not accompanied by any improvement or deterioration in their clinical condition. The article also reviews the literature on the prevalence, pathogenesis, diagnosis, and clinical features of adhesive arachnoiditis. Literature suggests that adhesive arachnoiditis following LESIs is a rare entity, which – as seen in our patients – has clear radiological characteristics but uncertain pathogenesis. It has a large spectrum of clinical presentation, ranging from an incidental finding to a serious neurological sequela. In at least some patients with adhesive arachnoiditis following LESI, the radiological and clinical findings may fail to correlate with each other. In light of the fact that LESI is one of the most commonly performed procedures for managing LBP, clinicians should be aware of this rare yet existing entity.

Neural Mobilization in a 54-Year-Old Woman With Postoperative Spinal Adhesive Arachnoiditis

OBJECTIVE

This case report describes the clinical features, complications, imaging characteristics, and management of postoperative spinal adhesive arachnoiditis.

CLINICAL FEATURES

A 54-year-old woman presented with right posterior thigh and leg pain after a lumbar spine fusion surgery to correct a degenerative spondylolisthesis of L3/4. Her pain was sharp and shooting and worsened with knee extension. A lumbar computed tomography myelogram demonstrated clumping and adhesion of the nerve rootlets in the cauda equina at the surgical fusion levels. Findings were consistent with spinal arachnoiditis.

INTERVENTION AND OUTCOME

The patient was treated with 2 sets of neural mobilization of the sciatic nerve with 15 repetitions each. Treatment was provided 2× per week for 3 weeks. The patient used the neural mobilization exercises at home and performed to tolerance. The patient's Oswestry Questionnaire was reduced significantly by 19% with decreased pain intensity of 2 points on the verbal analogue scale.

CONCLUSION

Neural mobilization was used successfully in the management of a patient with postoperative spinal arachnoiditis.

Diagnostic accuracy of diagnostic imaging for lumbar disc herniation in adults with low back pain or sciatica is unknown; a systematic review

Main text

We aim to summarize the available evidence on the diagnostic accuracy of imaging (index test) compared to surgery (reference test) for identifying lumbar disc herniation (LDH) in adult patients.For this systematic review we searched MEDLINE, EMBASE and CINAHL (June 2017) for studies that assessed the diagnostic accuracy of imaging for LDH in adult patients with low back pain and surgery as the reference standard. Two review authors independently selected studies, extracted data and assessed risk of bias. We calculated summary estimates of sensitivity and specificity using bivariate analysis, generated linked ROC plots in case of direct comparison of diagnostic imaging tests and assessed the quality of evidence using the GRADE-approach.We found 14 studies, all but one done before 1995, including 940 patients. Nine studies investigated Computed Tomography (CT), eight myelography and six Magnetic Resonance Imaging (MRI). The prior probability of LDH varied from 48.6 to 98.7%. The summary estimates for MRI and myelography were comparable with CT (sensitivity: 81.3% (95%CI 72.3-87.7%) and specificity: 77.1% (95%CI 61.9-87.5%)). The quality of evidence was moderate to very low.

Conclusions

The diagnostic accuracy of CT, myelography and MRI of today is unknown, as we found no studies evaluating today's more advanced imaging techniques. Concerning the older techniques we found moderate diagnostic accuracy for all CT, myelography and MRI, indicating a large proportion of false positives and negatives.