Routine Lumbar Magnetic Resonance Imaging Research Articles

Cauda Equina Atrophy in Amyotrophic Lateral Sclerosis on Routine Lumbar Magnetic Resonance Imaging.

The aim of the study was to evaluate the cross-sectional area of the cauda equina in amyotrophic lateral sclerosis (ALS) on routine lumbar magnetic resonance imaging and investigate the diagnostic accuracy in comparison with age- and sex-matched non-ALS controls. This retrospective study included 15 ALS patients and 15 age- and sex-matched non-ALS controls. Two independent neuroradiologists measured and compared the total cross-sectional area of the cauda equina of ALS patients and the non-ALS controls at the level of the L3 and L4 using axial T2-weighted images. The cutoff value, sensitivity, specificity, and area under the curve were measured. The interobserver reproducibility of the 2 independently obtained measurements was evaluated. The total cross-sectional area of the cauda equina in the ALS group was significantly smaller than that in the non-ALS group (L3: median, 66.73 vs 90.19 mm 2 , P < 0.001; L4: median, 52.9 vs 67.63 mm 2 , P < 0.001). The cutoff values at L3 and L4 were 76.95 and 61.04 mm 2 with a sensitivity and specificity of 1 and 0.87 and 0.8 and 0.87, respectively. The area under the curve at L3 and L4 were high at 0.96 and 0.94, respectively. The interobserver reproducibility was 0.88 at L3 and 0.89 at L4. The ALS patients showed significant atrophy of the cauda equina compared with non-ALS patients.

Added value of coronal-T1W sequence to the lumbar MR imaging protocol for low back pain.

:Introduction: Magnetic resonance imaging (MRI) is the most appropriate imaging method to investigate low back pain. As low back pain is very common, a large number of MRI scans are performed.Objective: To evaluate the extraspinal findings and clinical effect of the T1-weighted spin echo (T1 W SE) coronal sequence added to the lumbar MRI protocol for low back pain. Materials and methods: In 2015, we added a T1-weighted (T1W) coronal sequence to our routine lumbar MRI protocol. We retrospectively evaluated 969 lumbar MRI images for low back pain performed with this protocol. The extraspinal MRI findings obtained from them were then grouped as associated with low back pain (Category 1) and not associated with low back pain (Category 2). We also evaluated whether the recorded incidental extraspinal findings could be detected on conventional sagittal and axial images.Results: Ninety-six (63%) of the extraspinal findings were associated with low back pain (Category 1) and 56 (37%), Category 2. Seventy-eight percent of the extraspinal findings were detected only on coronal-T1W images and not on conventional images.Conclusion: Adding coronal-T1W sequence to the routine protocol of lumbar MRI can help to identify extraspinal findings and guide clinical treatment.

Coexisting Spine Lesions on Whole Spine T2 Sagittal MRI in Evaluating Spinal Degenerative Disease.

BackgroundStudies have reported on the usefulness of whole spine magnetic resonance imaging (MRI) in evaluating specific diseases such as spinal tuberculosis, spinal trauma, spondyloarthropathies, and multiple myeloma. In studies concerning degenerative spinal disease, sample sizes were small and some did not provide information on how symptomatic coexisting lesions were treated. We evaluated the types and prevalence of coexisting spine lesions found on whole spine T2 sagittal screening performed at the time of routine cervical and lumbar spine MRI and evaluated the efficacy of such screening in degenerative diseases of the cervical and lumbar spine.MethodsWe reviewed 1,757 and 2,266 consecutive cases where whole spine T2 sagittal screening had been performed with routine cervical and lumbar spine MRI, respectively, in patients with cervical and lumbar spinal degenerative diseases. Coexisting spine lesions were documented and statistical analysis was performed to investigate significant differences according to sex, age, and initial diagnosis. Electronic medical records were reviewed to determine whether additional interventions were necessary following such findings.ResultsWe reviewed 1,252 and 1,689 consecutive cases of routine cervical and lumbar spine MRI respectively, with whole spine T2 sagittal screening. Of the 1,252, 419 (33.5%) patients with cervical spinal degenerative disease had coexisting lesions in the thoracolumbar spine. Patients with ligament ossification disease of the cervical spine showed a higher prevalence of coexisting spine lesions. Sixty of the 419 (14.3%) patients with coexisting spine lesions warranted additional intervention or surgical treatment. Four hundred and eighty-one of 1,689 (28.5%) patients with lumbar degenerative disease had coexisting spine lesions in the cervicothoracic spine. Forty-eight of the 481 (10.0%) patients with coexisting spine lesions warranted additional intervention. In both patient groups, older patients showed a significantly higher prevalence of coexisting spine lesions than younger patients.ConclusionConsidering the minimal extra time and cost in performing whole spine screening, its application to routine spine MRI can be considered in evaluating cervical and lumbar spinal degenerative diseases.

Artificial Intelligence Comparison of the Radiologist Report With Endoscopic Predictors of Successful Transforaminal Decompression for Painful Conditions of the Lumber Spine: Application of Deep Learning Algorithm Interpretation of Routine Lumbar Magnetic Resonance Imaging Scan.

Identifying pain generators in multilevel lumbar degenerative disc disease is not trivial but is crucial for lasting symptom relief with the targeted endoscopic spinal decompression surgery. Artificial intelligence (AI) applications of deep learning neural networks to the analysis of routine lumbar MRI scans could help the primary care and endoscopic specialist physician to compare the radiologist's report with a review of endoscopic clinical outcomes. To analyze and compare the probability of predicting successful outcome with lumbar spinal endoscopy by using the radiologist's MRI grading and interpretation of the radiologic image with a novel AI deep learning neural network (Multus Radbot™) as independent prognosticators. The location and severity of foraminal stenosis were analyzed using comparative ordinal grading by the radiologist, and a contiguous grading by the AI network in patients suffering from lateral recess and foraminal stenosis due to lumbar herniated disc. The compressive pathology definitions were extracted from the radiologist lumbar MRI reports from 65 patients with a total of 383 levels for the central canal - (0) no disc bulge/protrusion/canal stenosis, (1) disc bulge without canal stenosis, (2) disc bulge resulting in canal stenosis, and (3) disc herniation/protrusion/extrusion resulting in canal stenosis. Both neural foramina were assessed with either - (0) neural foraminal stenosis absent, or (1) neural foramina are stenosis present. Reporting criteria for the pathologies at each disc level and, when available, the grading of severity were extracted and assigned into two categories: "Normal," and "Stenosis." Clinical outcomes were graded using dichotomized modified Macnab criteria considering Excellent and Good results as "Improved," and Fair and Poor outcomes as "Not Improved." Binary logistic regression analysis was used to predict the probability of the AI- and radiologist grading of stenosis at the 88 foraminal decompression sites to result in "Improved" outcomes. The average age of the 65 patients was 62.7 +/- 12.7 years. They consisted of 51 (54.3%) males and 43 (45.7%) females. At an average final follow-up of 57.4 +/- 12.57, Macnab outcome analysis showed that 86.4% of the 88 foraminal decompressions resulted in Excellent and Good (Improved) clinical outcomes. The stenosis grading by the radiologist showed an average severity score of 4.71 +/- 2.626, and the average AI severity grading was 5.65 +/- 3.73. Logit regression probability analysis of the two independent prognosticators showed that both the grading by the radiologist (86.2%; odds ratio 1.264) and the AI grading (86.4%; odds ratio 1.267) were nearly equally predictive of a successful outcome with the endoscopic decompression. Deep learning algorithms are capable of identifying lumbar foraminal compression due to herniated disc. The treatment outcome was correlated to the decompression of the directly visualized corresponding pathology during the lumbar endoscopy. This research should be extended to other validated pain generators in the lumbar spine. 3. Validity, clinical teaching, evaluation study.

Reliability Analysis of Deep Learning Algorithms for Reporting of Routine Lumbar MRI Scans.

Artificial intelligence could provide more accurate magnetic resonance imaging (MRI) predictors of successful clinical outcomes in targeted spine care. To analyze the level of agreement between lumbar MRI reports created by a deep learning neural network (RadBot) and the radiologists' MRI reading. The compressive pathology definitions were extracted from the radiologist lumbar MRI reports from 65 patients with a total of 383 levels for the central canal: (0) no disc bulge/protrusion/canal stenosis, (1) disc bulge without canal stenosis, (2) disc bulge resulting in canal stenosis, and (3) disc herniation/protrusion/extrusion resulting in canal stenosis. For both, neural foramina were assessed with either (0) neural foraminal stenosis absent or (1) neural foramina stenosis present. Reporting criteria for the pathologies at each disc level and, when available, the grading of severity were extracted, and the Natural Language Processing model was used to generate a verbal and written report. The RadBot report was analyzed similarly as the MRI report by the radiologist. MRI reports were investigated by dichotomizing the data into 2 categories: normal and stenosis. The quality of the RadBot test was assessed by determining its sensitivity, specificity, and positive and negative predictive value as well as its reliability with the calculation of the Cronbach alpha and Cohen kappa using the radiologist MRI report as a gold standard. The authors found a RadBot sensitivity of 73.3%, a specificity of 88.4%, a positive predictive value of 80.3%, and a negative predictive value of 83.7%. The reliability analysis revealed the Cronbach alpha as 0.772. The highest individual values of the Cronbach alpha were 0.629 and 0.681 when compared to the MRI report by the radiologist, rending values of 0.566 and 0.688, respectively. Analysis of interobserver reliability rendered an overall kappa for the RadBot of 0.627. Analysis of receiver operating characteristics (ROC) showed a value of 0.808 for the area under the ROC curve. Deep learning algorithms, when used for routine reporting in lumbar spine MRI, showed excellent quality as a diagnostic test that can distinguish the presence of neural element compression (stenosis) at a statistically significant level (P < .0001) from a random event distribution. This research should be extended to validated and directly visualized pain generators to improve the accuracy and prognostic value of the routine lumbar MRI scan for favorable clinical outcomes with intervention and surgery. 3. Validity, clinical teaching, and evaluation study.

The OLIF working corridor based on magnetic resonance imaging: a retrospective research

ObjectiveTo provide an anatomical basis for the development of oblique lumbar interbody fusion (OLIF) in Chinese patients.MethodsBetween November 2018 and June 2019, 300 patients’ lumbar MRI data were reviewed. According to the Moro system and zone method described by us, the axial view was vertically divided into 6 zones (A, I II, III, IV, P) and was horizontally divided into 4 zones (R, a, b, c, L). The locations of left psoas muscle and the major artery at L2/3, L3/4, and L4/5 levels were evaluated by the grid system. The aortic bifurcation segments will also be evaluated at the level of the vertebral body or the disc.ResultsAt the L2/3 level, left psoas muscle and the major artery in zone Ib were found in 28.0% of subjects, in zone IIb in 20.3%, and in zone Ic in 20.0%; at the L3/4 level, in zone Ab in 20.7% of subjects, in zone Ac in 26.0%, and in zone Ic in 11.0%; and at the L4/5 level, areas in zone Ab in 31.0% of subjects, in zone Ac in 26.0%, and in zone Ib in 11.7%. The aortic bifurcation segments were mainly at the L4 level. The zone of the left psoas muscle at all levels, the zone of the major artery at L4/5 level, and the zone of the aortic bifurcation segments had significant correlation with gender difference (P < 0.05).ConclusionThe left-sided OLIF at L2–L5 disc levels can be a feasible type of surgery for lumbar interbody fusion in the majority of Chinese patients. Before the operation, in order to screen out the appropriate surgical approach, routine lumbar magnetic resonance imaging is recommended to analyze the patient’s local anatomical features.

Diagnostic Importance of Axial Loaded Magnetic Resonance Imaging in Patients with Suspected Lumbar Spinal Canal Stenosis

To study the efficacy of lumbar (AL) magnetic resonance imaging (MRI) in patients with suspected lumbar spinal stenosis (LSS), with and without AL compression. Supine MRI is used in the assessment of patients with LSS. However, MRI findings may poorly correlate with neurologic findings because of the morphologic changes of the lumbar spinal canal between upright standing and supine positions. In patients without significant stenosis in routine lumbar MRI, by applying AL, MRI can show significant LSS. This study included 103 consecutive patients (188 disc levels) who presented with neurogenic claudication with and without low back pain. AL was performed using a nonmagnetic compression device for 5 minutes. T1- and T2-weighted axial and sagittal sequences were obtained during AL applied to the spine. The dural sac cross-sectional area (DSCA) appeared to be narrow at each disc level of L4-5 to L5-S1 in all patients and was measured using T2-weighted images in routine supine and AL images. The groups included patients with a reduction in the DSCA (>15 mm2) according to patient age and DSCA in routine spine MRI. The mean DSCA of the disc levels without and with AL were 138 mm2 and 123 mm2, with a mean difference of 15 mm2 at L4-5, 134 mm2 and 125 mm2 and a mean difference of 9 mm2 at L5-S1, respectively. The use of AL MRI in patients with clinically suspected LSS could reduce the risk of misdiagnosis of stenosis, leading to inappropriate treatment.

Complementary specific pelvic sequences on routine lumbar magnetic resonance imaging scans: an imaging-based study focused on piriformis syndrome

To discuss the rationale and merit of specific pelvic sequences as an adjunct to routine lumbar magnetic resonance imaging (MRI) for early detection of piriformis syndrome (PS) and to disclose its frequency in patients who underwent radiological evaluation. This retrospective, imaging-based study included all individuals who underwent lumbar MRI and those who were further evaluated with a pelvic MRI, but excluded all high-energy trauma cases. The patients' demographics and radiological features were reviewed using electronic patient records and hospital-based picture image archiving and communication system. Overall, 1321 individuals (659 females; 662 males) underwent lumbar MRI during the study period, and of these, 485 (238 females; 247 males) were further analyzed with a pelvic MRI for differential diagnosis. Forty patients (8.2%) (23 females; 17 males) were diagnosed with PS-all confirmed with MR neurography (MRN). On re-evaluation of all lumbar and pelvic MRIs and MRNs, we realized that adding just three specific pelvic sequences to routine lumbar MRI scans were enough to accurately delineate the piriformis muscle pathologies and sciatic nerve intensities. The calculated frequencies of PS in females, males, and the whole study population within 57 months were 3.49%, 2.57%, and 3.03%, respectively. Although PS being a clinical diagnosis, this study indicated that in patients whom PS was not suspected at the initial examination, 8.2% of them were finally diagnosed after MRI evaluations. Performing specific pelvic sequences as an adjunct to routine lumbar MRI can salvage underdiagnosed patients with PS and facilitate early detection of this pathological condition.

Sacral Neuromodulation Device Heating During Lumbar and Pelvic Magnetic Resonance Imaging—a Phantom Study

To evaluate radiofrequency-induced temperature rises associated with performing lumbar and pelvic magnetic resonance imaging (MRI) studies with an implanted sacral neuromodulation device using a phantom model. An accepted phantom model of radiofrequency-induced heating in human tissue was used to measure the temperature rise in the stimulator lead electrodes and impulse generator under the conditions used during routine clinical lumbar and pelvic MRIs in a 1.5Tesla MRI scanner. Testing configurations included an intact device (tined lead connected to generator), an intact lead, and a lead fragment (model of lead fracture). Variations in the position of the phantom relative to the scanner were also tested. During testing with the intact device or the lead fragment no significant heating was detected. In contrast, the isolated intact lead model showed heating up to 5°C. These tests provide preliminary evidence that the risk of heating is low for clinical lumbar and pelvic MRI at 1.5-Tesla with an intact sacral neuromodulation device system and with a fractured lead. However, there is a significant temperature change in the intact lead model.

3D-FSE Isotropic MRI of the Lumbar Spine

Retrospective diagnostic trial. To determine the diagnostic performance of 3-dimensional isotropic fast/turbo spin-echo (3D-TSE) in routine lumbar spine magnetic resonance imaging (MRI). Conventional 2-dimensional fast spin-echo (2D-FSE) MRI requires independent acquisition of each desired imaging plane. This is time consuming and potentially problematic in spine imaging, as the plane of interest varies along the vertical axis due to lordosis, kyphosis, or possible deformity. 3D-TSE provides the capability to acquire volumetric data sets that can be dynamically reformatted to create images in any desired plane. Eighty subjects scheduled for routine lumbar MRI were included in a retrospective trial. Each subject underwent both 3D-TSE and conventional 2D-FSE axial and sagittal MRI sequences. For each subject, the 3D-TSE and 2D-FSE sequences were separately evaluated (minimum 4 wk apart) in a randomized order and read independently by 4 reviewers. Images were evaluated using specific criteria for stenosis, herniation, and degenerative changes. The intermethod reliability for the 4 reviewers was 85.3%. Modified intermethod reliability analysis, disregarding disagreements between the lowest 2 descriptors for appropriate criteria (equivalent to "none" and "mild"), revealed average overall agreement of 94.6%. Using the above, modified criteria, interobserver variability for 3D-TSE was 89.1% and 88.3% for 2D-FSE (P=0.05), and intraobserver variability for 3D-TSE was 87.2% and 82.0% for 2D-FSE (P<0.01). The intermethod agreement between 3D-TSE and 2D-FSE was statistically noninferior to intraobserver 2D-FSE variability (P<0.01). This systematic evaluation showed that there is a very high degree of agreement between diagnostic findings assessed on 3D-TSE and conventional 2D-FSE sequences. Overall, intermethod agreement was statistically noninferior to the intraobserver agreement between repeated 2D-FSE evaluations. Overall, this study shows that 3D-TSE performs equivalently, if not superiorly to 2D-FSE sequences. Reviewers found particular utility for the ability to manipulate image planes with the 3D-TSE if there was greater pathology or anatomic variation.

Extraspinal Incidental Findings on Routine MRI of Lumbar Spine: Prevalence and Reporting Rates in 1278 Patients.

ObjectiveThe aim of the present study was to determine the prevalence and reporting rate of incidental findings (IF) in adult outpatients undergoing lumbar magnetic resonance imaging (MRI).Materials and MethodsRe-evaluation of a total of 1278 lumbar MRI images (collected from patients with a mean age of 50.5 years, range 16-91 years) captured between August 2010-August 2011 was done by a neuroradiologist and a musculoskeletal radiologist. IFs were classified according to organ or system (liver, gallbladder, kidney, bladder, uterus, ovary, lymph node, intestine and aorta). The rate of reporting of a range of IF was examined. The outcome of each patient's treatment was evaluated based on review of hospital records and by telephone interviews.ResultsA total of 253 IFs were found in 241 patients (18.8% of 1278). Among these, clinically significant IFs (n = 34) included: 2 renal masses (0.15%), 2 aortic aneurysms (0.15%), 2 cases of hydronephrosis (0.15%), 11 adrenal masses (0.86%), 7 lymphadenopathies (0.55%), 6 cases of endometrial or cervical thickening (0.47%), 1 liver hemangioma (0.08%), 1 pelvic fluid (0.08%) and 2 ovarian dermoid cysts (0.15%). Overall, 28% (71/253) of IFs were included in the clinical reports, while clinically significant findings were reported in 41% (14/34) of cases.ConclusionExtraspinal IFs are commonly detected during a routine lumbar MRI, and many of these findings are not clinically significant. However, IFs including clinically important findings are occasionally omitted from formal radiological reports.

Kissing Spine and the Retrodural Space of Okada: More Than Just a Kiss?

Baastrup (“kissing spine”) disease is characterized by contact by adjacent lumbar spinous processes and the presence of lumbar interspinous bursitis. The formation of an adventitious bursa within the interspinous region has been described previously in a retrospective review of routine lumbar magnetic resonance imaging in which the authors demonstrated the prevalence of interspinous bursitis in 8.2% of the study population [1]. These authors found an association between the formation of an interspinous bursa and the presence of associated degenerative changes such as central canal stenosis, disk bulging, and anterolisthesis. However, whether this bursa formation is the result of mechanical impingement from adjacent spinous processes or the result of degenerative conditions has not been fully characterized. Dr. Kikuzo Okada first described a communication pathway between single-level bilateral cervical facet joints in 1981 [2]. He described an extradural space dorsal to the ligamentum flavum that could connect the interlaminar region, interspinous region, and bilateral facet joints. This communication has been described in the lumbar spine, whereby interventional procedures in a single-sided facet joint have demonstrated flow of contrast material to the contralateral facet joint [3]. Usually “kissing spine” is thought to be caused by touching of approximating lumbar spinous processes during lumbar extension. This touching may create an adventitial bursa irritation within the interspinous ligament at the same level. However, we postulate that kissing spine disease may actually be an early sign of segmental instability. The anteroposterior shearing forces in persons with spondylolisthesis or early mid-range segmental instability may cause a friction moment, resulting in the interspinous formation of a bursa. Alternatively, excessive fluid within the facet joint caused by effusion may leak through the retrodural space of Okada to this region between the spinous processes and accumulate in the interspinous bursa. This bursa formation is different from a posterior facet joint synovial cyst in that the cyst has a contiguous relationship to the adjacent facet joint and is located in close proximity to the joint, whereas the adventitial bursa formation is more posterior within

Fat-suppressed t2* sequences for routine 3.0-tesla lumbar spine magnetic resonance imaging: a preliminary report

Clear depiction of the ligamentum flavum on routine lumbar magnetic resonance imaging (MRI) is essential in accurately describing the extent of degenerative disease. In routine, noncontrast evaluations, focal fatty deposition or hemangiomas can be difficult to distinguish from malignant foci on fast spin-echo (FSE) T2-weighted images. To describe the use of T2* fast field echo (T2FFE) in combination with spectral presaturation inversion recovery (SPIR) fat suppression for noncontrast, routine lumbar spine outpatient MR imaging at 3.0 Tesla (3T). An axial gradient echo (GE) T2FFE sequence was combined with SPIR fat suppression (T2FFE-SPIR), via a 3T Philips Intera (Philips Medical Systems, Best, The Netherlands) scanner, and added to the routine, noncontrast lumbar MRI examinations, which included sagittal FSE T1-weighted (T1WI), T2-weighted (T2WI), short-tau inversion recovery (STIR), and axial FSE T2WI. The sequence was performed in over 500 patients over a 1-year period, without intravenous contrast, and with slice thickness and planes of section identical to the axial FSE T1WI and T2WI images. The sequence typically lasted about 4.5-6 min. The use of T2FFE-SPIR enabled visualization of the ligamentum flavum in degenerative disease, and the exclusion of focal fatty lesions on FSE T2WI. Other benefits included: the identification of malignant foci, the uncommon detection of hemorrhage, and the elimination of spurious flow voids. Several brief examples are provided to demonstrate the utility of this technique. The addition of T2FFE-SPIR to routine, noncontrast protocols in outpatients could provide further confidence in the visualization of the ligamentum flavum in degenerative disease, and can exclude malignancy in T2-bright areas of focal fatty marrow. Larger studies would be helpful to evaluate the accuracy of this technique versus FSE techniques in depicting degenerative, malignant, or inflammatory disorders.

Spinal Cord Tumors of the Thoracolumbar Junction Requiring Surgery: A Retrospective Review of Clinical Features and Surgical Outcome

PurposeA retrospective review of medical records and imaging studies. To investigate characteristic clinical features and surgical outcomes of spinal cord tumors (SCTs) of the thoracolumbar junction (TLJ). The spinal cord transitions to the cauda equina in the TLJ. The TLJ contains the upper and lower motor neurons of the spinal cord and cauda equina. As a result, the clinical features of lesions in the TLJ vary, and these anatomical characteristics may affect surgical outcome.Materials and MethodsPathological diagnosis, clinical features, neurological signs, and surgical outcomes were investigated in 76 patients surgically treated at our institute for SCTs arising from T11 to L2. The patients were divided into epiconus (T11-12, n = 18) and conus groups (L1-2, n = 58).ResultsPatients in the epiconus group had hyperactive deep tendon reflexes (DTRs), while those in the conus group had hypoactive DTRs (p < 0.05). Nine patients were misdiagnosed with intervertebral disc diseases (IVDs) before correct diagnoses were made. It was impossible to definitively determine the exact cause of symptoms in four patients who had both SCTs and IVDs.ConclusionAmong SCTs of the TLJ, the epiconus group displayed upper motor neuron syndrome and the conus group displayed lower motor neuron syndrome. SCTs of the TLJ were frequently misdiagnosed as IVDs due to symptomatic similarities. SCTs of the TLJ should be included in differential diagnosis of back and leg pain, and it is highly recommended that routine lumbar magnetic resonance imaging include the TLJ.