Enhancing Annular Fissures and High-Intensity Zones: Pain, Internal Derangement, and Anesthetic Response at Provocation Lumbar Discography.

BACKGROUND AND PURPOSE: A high-intensity zone identified on preprocedural MR imaging is known to correlate with pain at provocation lumbar discography. The correlation between enhancing annular fissures and pain at provocation lumbar discography has not been comprehensively evaluated. The purpose of this study was to assess the pain response and imaging features at enhancing annular fissure nonoperated disc levels identified on preprocedural MR imaging with comparison with the high-intensity zone and nonenhancing disc levels in patients referred for provocation lumbar discography. MATERIALS AND METHODS: One-hundred nonoperated discs in 44 patients were retrospectively evaluated for an enhancing annular fissure on sagittal postcontrast T1-weighted pre-discogram MR imaging. Enhancing annular fissure discs were graded on the sagittal T2-weighted sequence (Grade 4: like CSF to Grade 1: negative/barely visible) for high-intensity-zone conspicuity. High-intensity-zone detection was performed independently. In the primary assessment, enhancing annular fissure and high-intensity zones were associated with pain response at provocation lumbar discography. Additional analysis included intradiscal anesthetic response and postdiscogram CT appearance. RESULTS: Thirty-nine discs demonstrated an enhancing annular fissure, with 23/39 demonstrating a high-intensity zone. The presence of a high-intensity zone predicted severe pain (concordant + nonconcordant; P = .005, sensitivity of 40%, specificity of 94%) and concordant pain (P = .007, sensitivity of 39%, specificity of 86%) at provocation lumbar discography. Enhancing annular fissures without a detected high-intensity zone were more frequently observed among severely painful (50%) and concordant (36%) discs than among discs negative for pain (9%; P = .01). This finding resulted in a substantially greater overall sensitivity of enhancing annular fissures for severe (P < .001, 64%) and concordant pain (P = .008, 61%), significantly improving the overall predictive ability of a high-intensity zone alone. A high-intensity zone went undetected in 9/11 Grade 1 disc levels with concordant pain present in 7/9. CONCLUSIONS: Consideration of enhancing annular fissures on preprocedural MR imaging substantially improves the prediction of severe/concordant pain in provocation lumbar discography.

Pain improvement after intradiskal lidocaine administration in provocation lumbar diskography: association with diskographic contrast leakage.

BACKGROUND AND PURPOSE: Our aim was to evaluate the relationship of pain reduction, after intradiskal lidocaine administration during provocation lumbar diskography, to the presence of contrast leakage on postdiskographic imaging. MATERIALS AND METHODS: Intradiskal lidocaine was injected at 182 significantly painful disk levels in 111 patients. The clinical records and imaging studies were reviewed for response to the lidocaine injection and for the presence/absence of diskographic contrast leakage on postdiskographic images and CT. Pain response was assigned the following grades: 1) complete or substantial improvement, 2) partial improvement, or 3) no significant improvement after lidocaine administration. Fluoroscopic imaging and postdiskographic CT were evaluated for the presence or absence of contrast leakage. RESULTS: Eighty-two (45%) significantly painful treated disks were contained, and 100 (55%) demonstrated contrast leakage. In leaking disks, 74 (74%) demonstrated complete or near-complete pain reduction after lidocaine administration, 15 (15%) demonstrated partial improvement, and 11 (11%) demonstrated no pain relief. In contained disks, 56 disks (69%) demonstrated no improvement after lidocaine administration, 9 (11%) demonstrating partial relief, and 17 (20%) demonstrated complete or substantial improvement. Results comparing leaking disks versus contained disks and complete versus no improvement were statistically significant (P<.001). CONCLUSION: Painful disks exhibiting diskographic leakage tend to be highly responsive to intradiskal lidocaine administration, whereas painful disks without diskographic leakage tend not to improve. This observation has implications with respect to targeting the origin of a patient's back pain and may have specific implications with respect to choice of treatment.

Lower cervical nerve root block using CT fluoroscopy in patients with large body habitus: another benefit of the swimmer's position.

We describe a method of performing lower cervical nerve root block (CNRB) with CT fluoroscopy in patients with large body habitus using the swimmer's position. This approach reduces image noise with acceptable visualization of vital structures and improved foraminal/root access. Anticipated use of the swimmer's position coupled with minimally modified radiation exposure parameters can limit radiation dose to operator/patient and reduce procedure time to match that of CNRB using CT fluoroscopy in typical patients.

CT-Fluoroscopic Cervical Transforaminal Epidural Steroid Injections: Extraforaminal Needle Tip Position Decreases Risk of Intravascular Injection.

BACKGROUND AND PURPOSE: Cervical transforaminal epidural steroid injections are commonly performed for temporary pain relief or diagnostic presurgical planning in patients with cervical radiculopathy. Intravascular injection of steroids during the procedure can potentially result in cord infarct, stroke, and even death. CT-fluoroscopy allows excellent anatomic resolution and precise needle positioning. This study sought to determine the safest needle tip position during CT-guided cervical transforaminal epidural steroid injection as determined by the incidence of intravascular injection. MATERIALS AND METHODS: We retrospectively evaluated procedural imaging for consecutive single-site CT-fluoroscopic cervical transforaminal epidural steroid injection performed during a 13-month period. Intravascular injections were identified and classified by volume, procedure phase, vessel type, and needle tip position relative to the targeted neural foramen. ANOVA, Wilcoxon, or Pearson χ(2) testing was used to assess differences among groups as appropriate. RESULTS: Intravascular injections occurred in 49/201 (24%) procedures. Of the intravascular injections, 13/49 (27%) were large, 10/49 (20%) were small, and 26/49 (53%) were trace volume. Sixteen of 49 (33%) intravascular injections occurred with a trial contrast dose; 27/49 (55%), with a steroid/analgesic cocktail; and 6/49 (12%), with both. Twenty-seven of 49 (55%) intravascular injections were likely venous, 22/49 (45%) were indeterminate, and none were likely arterial. The intravascular injection rate was significantly lower (P < .001) for the extraforaminal needle position (8/82, 10%) compared with junctional (27/88, 31%) and foraminal (14/31, 45%) needle tip positions. CONCLUSIONS: An extraforaminal needle position for CT-guided cervical transforaminal epidural steroid injection decreases the risk of intravascular injection and therefore may be safer than other needle tip positions.

Neuroradiologic aspects of pediatric orthotopic liver transplantation.

To investigate the occurrence of neurologic symptomatology in pediatric orthotopic liver transplantation patients and to evaluate the utility of CT in uncovering the origin of their symptoms, we reviewed the medical records and head scans (when performed) of 71 patients. Neurologic problems occurred in 48%; the majority involved seizures, mental status changes, or coma. Patients who only had seizures generally had negative CT scans, except for two patients with minimal subarachnoid hemorrhages. Three-quarters of the comatose patients, however, had significant intracerebral hemorrhages defined by CT. Prominent sulci and ventricles were found in approximately one-third of the patients scanned, but did not correlate with symptomatology or steroid dose.

Cerebellar venous angioma: "benign" entity?

Four patients with bleeding venous angiomas in the cerebellar hemispheres are reported. All of the hemorrhages were subacute; three were recurrent. A literature review substantiated venous angioma as a recognized source of spontaneous cerebellar hemorrhage. Cerebellar venous angiomas may be more prone to bleed than venous angiomas in other locations. Their natural history seems to be similar to that of arteriovenous malformations. Though a minority bleed, the hemorrhagic event can be acute or subacute, recurrent, or catastrophic. Thus the clinical course is not always innocuous.

Callosomarginal infarction secondary to transfalcial herniation.

To evaluate the prevalence of anterior cerebral artery infarcts in the context of transfalcial herniation, 1100 cerebral CT scans were reviewed. Three patients had acute intracranial hemorrhages resulting in transfalcial herniation and subsequent focal ipsilateral paracentral lobule or superior frontal gyrus infarcts. The infarcts are presumed to have resulted from compression and compromise of the terminal portions of the callosomarginal artery against the falx. Callosomarginal infarcts are reflective of severe, acute hemispheric insult. As such, they seem to portend a declining clinical condition, and thus may provide another CT indication of a poor clinical outcome.

Acute tissue tear hemorrhages of the brain: computed tomography and clinicopathological correlations.

Tissue tear hemorrhages (TTHs) are often seen on high-resolution computed tomographic scans after closed head injury. Generally, TTHs have been thought to be visible manifestations of more severe forms of diffuse axonal injury and thus portend a poor prognosis. Computed tomographic scans from 600 patients with head injuries were reviewed; 48 (8%) were found to have TTHs. The clinical spectrum of TTHs was characterized. No direct relationship could be established between either the presence or the number of TTHs and the severity and/or outcome from the head injury in this group, except that patients with TTHs in both the brain stem and the corpus callosum uniformly had a poor outcome. Magnetic resonance imaging provided more sensitive information than computed tomography in evaluating TTHs.

Robust midsagittal plane extraction from normal and pathological 3-D neuroradiology images.

This paper focuses on extracting the ideal midsagittal plane (iMSP) from three-dimensional (3-D) normal and pathological neuroimages. The main challenges in this work are the structural asymmetry that may exist in pathological brains, and the anisotropic, unevenly sampled image data that is common in clinical practice. We present an edge-based, cross-correlation approach that decomposes the plane fitting problem into discovery of two-dimensional symmetry axes on each slice, followed by a robust estimation of plane parameters. The algorithm's tolerance to brain asymmetries, input image offsets and image noise is quantitatively evaluated. We find that the algorithm can extract the iMSP from input 3-D images with 1) large asymmetrical lesions; 2) arbitrary initial rotation offsets; 3) low signal-to-noise ratio or high bias field. The iMSP algorithm is compared with an approach based on maximization of mutual information registration, and is found to exhibit superior performance under adverse conditions. Finally, no statistically significant difference is found between the midsagittal plane computed by the iMSP algorithm and that estimated by two trained neuroradiologists.

Management of neurocytomas: case report and review of the literature.

The purpose of this report is to review the available literature on the presentation, pathology, and treatment of central nervous system (CNS) neurocytomas. A case report of an extraventricular neurocytoma is presented along with a comprehensive literature search of patients with a diagnosis of CNS neurocytoma. CNS neurocytomas are rare neoplasms, with fewer than 240 cases reported in the literature. The majority of neurocytomas are found in the ventricular system of the brain. Immunohistochemistry is frequently used to help distinguish this tumor from other CNS neoplasms. MIB-1 proliferation index is commonly used in an attempt to predict biologic behavior. Little is known about the management of patients with this tumor, because most reports are from the pathologic literature and contain sparse information regarding clinical management. Neurocytomas are rare CNS tumors with varied biologic behavior. MIB-1 index may help direct adjuvant therapy. An excellent prognosis can be expected if a gross total resection is achieved. Postoperative radiation therapy (RT) may be considered after subtotal resection. Otherwise, RT is an option for medically inoperable or recurrent disease.

Diagnosis of Os odontoideum using kinematic magnetic resonance imaging. A case report.

STUDY DESIGN: A case of os odontoideum diagnosed using kinematic magnetic resonance imaging is presented. OBJECTIVES: To evaluate the kinematic magnetic resonance imaging findings of os odontoideum and the possible use these findings might have to guide treatment. BACKGROUND: Kinematic magnetic resonance imaging is a new imaging modality that is able to produce realtime images of a structure through a range of motion. This makes it well suited for investigating dynamic processes such as cervical instability. METHODS: A single subject with known os odontoideum was examined using a Sigma SPR Kinematic Magnetic Resonance Imager (General Electric, Florence, SC). RESULTS: Kinematic magnetic resonance imaging demonstrated cervical spinal cord impingement and cervical instability throughout flexion and extension, but not during lateral bending or rotation. CONCLUSIONS: Kinematic magnetic resonance imaging can evaluate the cervical spine in an axially loaded position throughout its range of motion. This modality may be a useful method for diagnosing and classifying abnormalities of the spine.

Absent cord sign in acute spinal trauma.

Review of magnetic resonance imaging (MRI) findings in 100 patients suffering acute spinal trauma from 1985 to 1987 revealed four patients who had suffered thoracic spine fractures and acute subarachnoid hematomas. The spinal cord was not demonstrated on the T1-weighted sagittal MRI due to the similarities in signal intensity between the spinal cord and acute hemorrhage. Nonvisualization of the thoracic cord should not be presumed to be artifactual until subarachnoid hematoma is excluded.

Degenerative disease of the lumbar spine. Role of CT-myelography in the MR era.

One hundred patients with degenerative disease of the lumbar spine on whom both magnetic resonance (MR) and computed tomography (CT)-myelography were performed were reviewed. In one-third of the cases, the CT-myelogram provided additional useful information. This included definition of the extent of large disc herniations, demonstration of focal neural compression by small herniations, and clarifying abnormalities of the facets, including synovial cysts. These results should help to refine the indications for CT-myelography, which continues to be requested extensively.

Targeted CT-guided epidural blood patch for treatment of spontaneous intracranial hypotension due to calcified intradural thoracic disc herniation.

Calcified thoracic intradural disc herniations have recently been reported as a cause of spontaneous intracranial hypotension (SIH). We report successful treatment of SIH with a targeted CT-guided epidural blood patch. A 57-year-old man presented to the emergency department with a two-week history of progressively debilitating headache. CT and MRI of the brain showed findings consistent with intracranial hypotension and MRI of the spine showed findings consistent with CSF leak. Subsequent CT myelogram of the thoracic spine confirmed the presence of CSF leak and calcified disc herniations at the T6-7, T7-8 and T8-9 levels indenting the ventral dura and spinal cord. The calcified disc herniation at T6-7 had an intradural component and was therefore the most likely site of the CSF leak. Under CT fluoroscopic guidance, a 20-gauge Tuohy needle was progressively advanced into the dorsal epidural space at T6-7. After confirmation of needle tip position, approximately 18cc of the patient's own blood was sterilely removed from an arm vein and slowly re-injected into the dorsal epidural space. With satisfactory achievement of clot formation, the procedure was terminated. The patient tolerated the procedure well. The next morning, his symptoms had completely resolved and he was neurologically intact. At five-week follow up, he was symptom-free. Targeted epidural blood patch at the site of presumed CSF leak can be carried out in a safe and effective manner using CT fluoroscopic guidance and can be an effective alternative to open surgical management in selected patients.

Immediate pain response to interlaminar lumbar epidural steroid administration: response characteristics and effects of anesthetic concentration.

BACKGROUND AND PURPOSE: Interlaminar LESIs are commonly used to treat LBP or radiculopathy. Most studies focus on the long-term outcomes of LESI. The purpose of this study is to evaluate the immediate effects of fluoroscopically guided LESI on LBP/radiculopathy including low- or high-strength anesthetic response. MATERIALS AND METHODS: The procedure notes, post-procedure records, and imaging records dedicated spine nurse assessments, and imaging records were retrospectively evaluated in 392 fluoroscopically guided LESIs performed in 276 patients (nonrandomized, nonblinded; 131 males, 145 females; average age, 56 years) with LBP/radiculopathy using either low- or high-strength anesthetic (80 mg of methylprednisilone mixed with bupivacaine [0.25% or 0.5%]). Post-procedure documentation of the patient's pre- and postprocedure VAS pain-scale level were tabulated. RESULTS: Single LESI was performed in 199 patients, with multiple LESIs in 77 (193 injections). Low-strength bupivacaine (0.25%) was used in 237 injections, with high-strength (0.5%) in 155. Complete to near-complete immediate pain relief (<20% residual pain) was reported after 197 of 392 (50.3%) injections. No pain relief was reported after 60 (15.4%) injections (>80% residual), with partial relief in the remainder. No statistical difference was noted between low- and high-anesthetic strength or between single- and multiple-injection patients. In multiple-LESI patients, consistent pain relief response was noted in 39 of 77 (50.6%) patients, with improving LESI response in 20.8%, deteriorating LESI response in 19.5%, and variable response in 9.1%. CONCLUSIONS: An immediate pain-extinction response is identified after LESI, which appears independent of anesthetic strength. This observation may relate to pain origin and/or pain nociceptor afferent pathway in an individual patient and potentially relate to treatment response.

'Progressive-onset' versus injury-associated discogenic low back pain: features of disc internal derangement in patients studied with provocation lumbar discography.

Chronic low back pain (LBP) can be 'progressive onset' or injury-related. This study compares the patient-reported cause of chronic LBP to features of disc internal derangement at painful concordant discs evaluated by provocation lumbar discography. Concordant LBP was identified in 114 patients with chronic LBP studied by provocation discography. LBP cause, discogram pain response and discogram/post-discogram CT features of internal derangement were retrospectively reviewed. 'Progressive-onset' LBP was reported in 32 (28%) patients, injury-related LBP in 75 (66%) with LBP equated to non-specific causes in seven. Injury-related LBP was more commonly identified in men (52 of 63 [83%]) with women reporting near-equal frequency of 'progressive-onset' (23 of 44 [52%]) and injury-related (21 of 44 [48%]) LBP (p=0.002). In 172 concordant painful discs, near-equal frequency of severely degenerative (Dallas grade-3: 82 of 172 [47.3%]) and full-thickness radial fissure discs (Dallas grade-3: 90 of 172 [52.7%]) were identified. Women with 'progressive-onset' LBP demonstrated more frequent severely degenerative discs (24 of 37 [65%]); women with injury-related LBP demonstrated more frequent radial-defect discs (21 of 31 [68%]; p=0.01). In men with injury-related LBP, severe degeneration-only (44 of 89 [49%]) and radial defect discs (45 of 89 [51%] were seen with equal frequency. In men with 'progressive-onset' LBP, radial defects are more common (11 of 15 [73%]). 'Progressive-onset' and injury-related chronic LBP subgroups are definable. Gender-related differences in incidence and internal derangement features at concordant discs are identified at discogram/post-discogram CT. These differences may have implications related to LBP origin/treatment-response.

Peripheral disc margin shape and internal disc derangement: imaging correlation in significantly painful discs identified at provocation lumbar discography.

Annular margin shape is used to characterize lumbar disc abnormality on CT/MR imaging studies. Abnormal discs also have internal derangement including annular degeneration and radial defects. The purpose of this study was to evaluate potential correlation between disc-margin shape and annular internal derangement on post-discogram CT in significantly painful discs encountered at provocation lumbar discography (PLD). Significantly painful discs were encountered at 126 levels in 86 patients (47 male, 39 female) studied by PLD where no prior surgery had been performed and response to intradiscal lidocaine after provocation resulted in either substantial/total relief or no improvement after lidocaine administration. Post-discogram CT and discogram imaging was evaluated for disc-margin characteristics (bulge/protrusion), features of disc internal derangement (radial annular defect [RD: radial tear/fissure/annular gap], annular degeneration) and presence/absence of discographic contrast leakage. In discs with focal protrusion, 50 of 63 (79%) demonstrated Grade 3 RD with 13 (21%) demonstrating severe degenerative change only. In discs with generalized-bulge-only, 48 of 63 (76%) demonstrated degenerative change only (primarily Dallas Grade 3) with 15 of 63 (24%) demonstrating a RD (Dallas Grade 3). Differences were highly statistically significant (p<0.001). Pain elimination with intra-discal lidocaine correlated with discographic contrast leakage (p<0.001). Disc-margin shape correlates with features of internal derangement in significantly painful discs encountered at PLD. Discs with focal protrusion typically demonstrate RD while generalized bulging discs typically demonstrated degenerative changes only (p<0.001). Disc-margin shape may provide an important imaging clue to the cause of chronic discogenic low back pain.

Adjacent double-nerve root contributions in unilateral lumbar radiculopathy.

BACKGROUND AND PURPOSE: Image-guided selective nerve root block/steroid injection is commonly performed for lumbar radiculopathy. The purpose of this study was to evaluate the clinical/imaging characteristics and injection response of adjacent double-root contributions to unilateral lumbar radiculopathy in a typical interventional spine practice. MATERIALS AND METHODS: In 132 of 350 patients (37.7%) with unilateral radiculopathy, adjacent double-nerve root block/steroid injection was performed on the basis of preprocedural clinical/imaging characteristics. Clinical presentation (pain pattern, VAS), response to injection, and imaging features of potential root compression/irritation (disk protrusion, subarticular/foraminal stenosis) were tabulated. RESULTS: Clinically, a subset of patients with both L4+L5 and L5+S1 radiculopathy presented with proximal sciatica only in addition to those with typical L4, L5 or S1 radicular patterns. Preprocedural imaging demonstrated evidence of adjacent double-root abnormality in 56 of 79 (71%) patients without prior surgery (single-level disease, 32; 2-level disease, 24) and in all 53 patients with prior lumbar surgery (scar, 42; separate-level root abnormality, 13). Adjacent double-level replication of the patient's familiar pain was present in 82 of 132 (62%) patients, with single-root replication in 37 (28%) and no response in 13 (10%). Typical sciatica was encountered by injection at L4 (15%-33%), likely reflecting furcal nerve lumbar plexus contribution from L5. Sensations from each injected root usually replicated separate recognizable portions of the patient's radiculopathy, with marked or complete pain improvement reported in most patients. CONCLUSIONS: Adjacent double-level contributions to lumbar radiculopathy are common, and clinical/imaging clues should be assessed to ensure optimum nerve root block/steroid injection treatment response.