MRI Spectrum of Symptomatic and Non –Symptomatic Tarlov Cyst: Series of Seven Cases in Orthopaedic Management Point of View

Tarlov cysts are perineural cysts and are usually found in sacral region. The dorsal nerve root is encased in this type of the cyst. These may or may not be with any of the symptomatology. The entity is infrequently found as an incidental finding. These are cerebrospinal fluid (CSF) filled sacs which are diagnosed on cross sectional imaging modalities especially in magnetic resonance imaging (MRI). Tarlov cysts can cause different type of myelopathies as per their location and size. Methods: We present a series of seven cases where these perineural cysts were found during the routine imaging of lumbosacral spine. All these patients had undergone Magnetic Resonance Imaging (MRI) of lumbosacral spine for backache or some other pelvic complaints. In one case Computerized Tomography (CT) Myelography also helped in diagnosis and related bone remodeling.MR myelography adds to the delineation of CSF wrapping around the spinal cord. Results: Three patients were found to be symptomatic and the intensity of complaints corresponded to the size and location of the cysts. In our three cases, the etiopathogenesis also corresponded to the underlying development of these entities. Four patients were asymptomatic as the size of these cysts were small and not contributing to the complaints of the patient. Conclusion: MRI is the best modality to diagnose these perineural cysts which are responsible for different types of myelopathies .T2WI sequences in non contrast MRI studies are the best in delineating the size, shape, outline and location of these cysts. This also further elaborates their extension to the surrounding regions.MR myelography is adjuvant to more morphological features of these cysts.

CT myelography of the thoraco-lumbar spine in 8 dogs with degenerative myelopathy

CT myelography of the T11-L2 region was performed in 8 large-breed dogs with a clinical diagnosis of degenerative myelopathy (DM) and 3 large-breed dogs that were clinically normal. CT myelographic characteristics were recorded for each dog, at each disc level. Area measurements of the spinal cord, dural sac, vertebral canal, and vertebral body were recorded at 4 slice locations for each disc level. Mean area ratios were calculated and graphically compared, by slice location and group. In all dogs, CT myelography identified morphologic abnormalities that were not suspected from conventional myelograms. Characteristics observed with higher frequency in DM versus normal dogs were: spinal stenosis, disc protrusion, focal attenuation of the subarachnoid space, spinal cord deformity, small spinal cord, and paraspinal muscle atrophy. Mean spinal cord: dural sac, spinal cord: vertebral canal, dural sac: vertebral canal, and vertebral canal:vertebral body ratios were smaller in DM versus normal dogs at more than one disc level. Some CT myelographic characteristics in DM dogs were similar to those previously reported in humans, dogs and horses with stenotic myelopathy.

Interobserver Reliability between MRI, CT-myelogram and Myelogram in the Evaluation of Lumbar Spinal Stenosis / 대한정형외과학회잡지

PURPOSE: We designed this study to evaluate the interobserver reliability of magnetic resonance imaging (MRI), post-myelographic computed tomography (CT-myelogram) and myelography for the diagnosis of lumbar spinal stenosis. MATERIALS AND METHODS: Thirty two patients with lumbar spinal stenosis were evaluated preoperatively by MRI, CT-myelography, and myelography by four observers. For each set of scans, the examiners assessed the presence or absence of; 1) intervertebral disk protrusion, 2) facet arthrosis, 3) ligamentum flavum hypertrophy, and 4) nerve root impingement. The severities of 1) central, 2) lateral, 3) foraminal and 4) entire spinal stenosis were graded using a four-point scale range from 1 (no stenosis) to 4 (severe stenosis). RESULTS: Kappa statistical analysis revealed moderate interobserver agreement in terms of disk protrusion (0.49), nerve root impingement (0.42) and lateral stenosis grade based on MRI. Low levels of agreement were found for facet arthrosis and ligamentum flavum hypertrophy. Relatively higher levels of agreement were found for nerve root impingement, lateral stenosis and entire stenosis, graded by MRI and for central stenosis graded by myelography. CONCLUSION: The results of this study reflect that MRI showed relatively higher levels of interobserver reliability than the other diagnostic modalities in the evaluation of patients with lumbar spinal stenosis.

A comparison of MR myelography of brachial plexus injury with CT myelography and conventional myelography.

The purpose of study is to assess the accuracy of magnetic resonance myelography (MRM) of the cervical spine in patients with preganglionic Brachial Plexus Injury (BPI) by using CT myelography as the gold standard and comparing this with routine conventional myelography. Patients with a clinically diagnosis of Brachial plexus Injury were studied (9 males, 1 female, aged 16 - 42 years old) [mean age = 25.4 years old]). All patients had undergone clinical evaluation by an orthopedic surgeon and five patients had had additional somatosensory evoked potentials (SEP) performed. All patients were investigated by conventional myelography, computed tomography myelography (CTM) and magnetic resonance myelography (MRM). We used CT myelography as the gold standard and the accuracy of MRM and myelography were assessed in relative to this. The sensitivity in detecting a pseudomeningocele by MRM is 100% and the sensitivity in detecting nerve root abnormality is 90% at the level of the C5, C6 roots and 100% for the C7, C8, T1 roots. MR Myelography had many advantages over conventional and CT myelography which include the absence of radiation and the lack of need for intrathecal injection of contrast medium.

The Pathomorphologic Study of Spinal Stenosis as Seen on CT - Myelography of the Lumbar

This study has been examined different morphologic measurements in the evaluation of patients with lumbar spinal stenosis. Preoperative CT-Myelography from 30 patients who underwent surgery for central lumbar stenosis were analyzed. Based on this, we concluded as follows : 1) Bony measurement alone did not reliably identify patients with spinal stenosis. 2) Measurement of the transverse area of the dural sac on CT-Myelography was the most accurate method for identifying stenosis. 3) Lumbar myelography was still considered to have an important role in the valuation of a patient with stenosis because of correlation between the cross-sectional area of the dural sac and the anteroposterior diameter of the dural sac was excellent. 4) We identified soft-tissue problems as the main cause of stenosis. 5) The most common level of maximum stenosis was L4-5.

Diagnostic Value of Spinal Computed Tomography Scan

Since Di Chiro et al. first reported on computed tomography(CT) in syringomyelia, spinal CT has slowly but steadily gained in importance. Recently, application of advanced scanning equipment has led to considerable progress in the evaluation of spinal canal and disc diseases. Since April to December 1982 we have evaluated 96 spine patients by a high-resolution GE 8800 CT scanner. 1) High-resolution non-enhanced CT images provide clear visualization of soft tissue as well as bony structures of the spine, particularly of the lumbar spine. 2) Unenhanced CT of the lumbar spine is highly effective in the diagnosis of herniated disc or the evaluation of bony entrapment syndrome. 3) High-resolution CT aids in the evaluation of destructive neoplastic disease and of burst fracture of the spine. 4) So high-resolution CT is considered the most important noninvasive primary screening test in the diagnosis of herniated lumbar disc or spinal stenosis as well as in the evaluation of primary or metastatic spinal lesion.