Critical Assessment of Myelography Practices: A Call for Rational Guideline Revision.

BACKGROUND AND PURPOSE: Patient preparation for myelography and postprocedural monitoring varies widely between practices, despite published guidelines. Our aim was to examine the current practice variations in discontinuing reportedly seizure threshold-lowering medications before myelography and to assess the reported incidence of postmyelographic seizures. MATERIALS AND METHODS: An e-mail survey was sent to American Society of Neuroradiology members concerning the number of postmyelographic seizures experienced in the past 5 years, the presence of an institutional policy for discontinuing seizure threshold-lowering medications, and the type of myelographic contrast used. We compared the postmyelographic seizure frequency in the responses. RESULTS: Of 700 survey responses, 57% reported that they do not discontinue seizure threshold-lowering medications before myelography. Most (97%) indicated never having a patient experience a seizure following myelography. The number of postmyelographic seizures between those who discontinue seizure threshold-lowering medications and those who do not was not statistically significant (OR = 2.13; 95% CI, 0.91-4.98; P = .08). Most (95%) reported using nonionic hypo-osmolar agents. CONCLUSIONS: Survey results revealed widely variable practices for patient myelography preparation and postprocedural monitoring. We found no difference in reported seizures between those who discontinued seizure threshold-lowering medications and those who did not. In light of our findings, we propose that discontinuing reportedly seizure threshold-lowering medications is not warranted with the current nonionic water-soluble contrast agents and may be potentially harmful in some instances. This work supports revision of existing recommendations to withhold such medications before myelography.

Comparative accuracies of electrodiagnostic and imaging studies in neonatal brachial plexus palsy.

OBJECTIVEThe incorporation of ancillary testing in the preoperative setting for patients with neonatal brachial plexus palsy (NBPP) remains controversial, but the recommendation for early nerve reconstruction when a baby has a preganglionic lesion at the lower nerve roots is generally accepted. At some specialty centers, nerve surgeons use preoperative electrodiagnostic testing (EDX) and imaging to aid in lesion localization and the preoperative planning of the nerve reconstruction. EDX and imaging have been evaluated for their abilities to detect pre- and postganglionic lesions, but their accuracies have never been compared directly in the same set of patients. The aim of the present study was to evaluate the accuracy of imaging and EDX in an NBPP population.METHODSA retrospective review was conducted of 54 patients with operative NBPP seen between 2007 and 2017. The patients underwent EDX and imaging: EDX was performed, and the results were reviewed by board-certified electrodiagnosticians, and imaging was reviewed by board-certified neuroradiologists. The gold standard was considered to be the findings at surgical exploration. Descriptive and analytical statistics were utilized to compare the accuracies of imaging and EDX.RESULTSThe mean age at surgery was 6.94 mos (± 4 mos). Fifteen patients (28%) were Narakas grade I-II, and 39 (72%) were Narakas grade III-IV. For all nerve roots, the overall accuracy of detecting preganglionic lesions was 74% for EDX and 69% for imaging. The overall sensitivity of detecting preganglionic lesions by EDX was 31%, but the specificity was 90%. The overall sensitivity of detecting preganglionic lesions by imaging was 66%, and the overall specificity was 70%. However, at C8, EDX was 37.5% sensitive and 87.5% specific, whereas imaging was 67.7% sensitive but only 29.4% specific.CONCLUSIONSEDX outperformed imaging with regard to specificity and accuracy of identifying preganglionic injuries. This finding is especially relevant in the lower nerve roots, given that lower plexus preganglionic lesions are an accepted indication for early intervention.

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.

The value of dynamic radiographic myelography in addition to magnetic resonance imaging in detection lumbar spinal canal stenosis: A prospective study.

OBJECTIVE: MRI is regarded as the study of choice in the diagnosis of lumbar spinal stenosis. In some cases, the supine MRI leads to a misdiagnosis in the extent of lumbar spinal stenosis. Dynamic myelography can detect lumbar spinal stenosis in these cases of where the MRI may not be as sensitive. To compare the sensitivities of dynamic radiographic myelography and supine MRI in lumbar canal stenosis (LCS) patients and to determine whether dynamic radiographic myelography is a valuable diagnostic exam in the work-up of lumbar canal stenosis. PATIENTS & METHODS: Over two years, the imaging data of 100 consecutive patients who were suspected of having LCS were prospectively analyzed. All lumbar intervertebral segments were evaluated in each patient on sagittal MR T2-weighted images and lateral plane images by myelography using a semi-quantitative scoring system. The differences in scores for 5 motion segments under 3 conditions (supine MRI, upright sitting myelography and standing myelography with extension) were analyzed statistically. RESULTS: Of 100 patients with 500 analyzed intervertebral segments, 23 patients with inconclusive supine MRI results had LCS in standing myelography with extension. Compared with upright sitting myelography and supine MRI, standing myelography with extension yielded the highest score for every segment from L1/2 to L5/S1. Compared with the upright sitting myelography position, 61 more patients received a diagnosis of lumbar stenosis in the standing myelography with extension position, and 121 more stenotic segments were diagnosed. Compared with the supine MRI position, standing myelography with extension detected 64 more stenotic patients and 137 more stenotic segments. CONCLUSIO: n Based on a large patient sample, dynamic myelography is a valuable diagnostic tool in detecting lumbar spinal stenosis. Patients with lumbar spinal stenosis may have inconclusive supine MRI in 23% of cases being misdiagnosed as normal. This missed rate of LCS patients with unclear supine MRI results can be avoided with dynamic myelography. The combination of supine MRI and dynamic myelography is critical in the evaluation of LCS, especially if multisegmental findings are detected.

Reduction of contractility and reactivity in isolated lymphatics from hemorrhagic shock rats with resuscitation

PURPOSE: To evaluate the changes of contractility and reactivity in isolated lymphatics from hemorrhagic shock rats with resuscitation. METHODS: Six rats in the shock group suffered hypotension for 90 min by hemorrhage, and resuscitation with shed blood and equal ringer's solution. Then, the contractility of lymphatics, obtained from thoracic ducts in rats of the shock and sham groups, were evaluated with an isolated lymphatic perfusion system using the indices of contractile frequency (CF), tonic index (TI), contractile amplitude (CA) and fractional pump flow (FPF). The lymphatic reactivity to substance P (SP) was evaluated with the different volume of CF, CA, TI and FPF between pre- and post-treatment of SP at different concentrations. RESULTS: The CF, FPF, and TI of lymphatics obtained from the shocked rats were significantly decreased than that of the sham group. After SP stimulation, the ∆CF (1×10-8, 3×10-8, 1×10-7, 3×10-7 mol/L), ∆FPF (1×10-8, 3×10-8, 1×10-7 mol/L), and ∆TI (1×10-8 mol/L) of lymphatics in the shock group were also obviously lower compared with the sham group. In addition, there were no statistical differences in CA and ∆CA between two groups. CONCLUSION: Lymphatic contractility and reactivity to substance P appears reduction following hemorrhagic shock with resuscitation. .

Technical compliance to standard guidelines for lumbar puncture and myelography: survey of academic neuroradiology attendings and fellows.

RATIONALE AND OBJECTIVES: To assess technical compliance among neuroradiology attendings and fellows to standard guidelines for lumbar puncture and myelography to minimize procedural complications such as iatrogenic meningitis and spinal headache. MATERIALS AND METHODS: We surveyed academic neuroradiology attendings and fellows in the e-mail directory of the Association of Program Directors in Radiology. We queried use of face masks, use of noncutting needles, and dural puncture practices. All data were collected anonymously. RESULTS: A total of 110 survey responses were received: 75 from neuroradiology attendings and 34 from fellows, which represents a 14% response rate from a total of 239 fellows. Forty-seven out of 101 (47%) neuroradiologists do not always wear a face mask during myelograms, and 50 out of 105(48%) neuroradiologists do not always wear a face mask during lumbar punctures, placing patients at risk for iatrogenic meningitis. Ninety-six out of 106 neuroradiologists (91%) use the Quincke cutting needle by default, compared to only 17 out of 109 neuroradiologists (16%) who have ever used noncutting needles proven to reduce spinal headache. Duration of postprocedure bed rest does not influence incidence of spinal headache and may subject patients to unnecessary monitoring. Only 15 out of 109 (14%) neuroradiologists in our study do not prescribe bed rest. There was no statistically significant difference in practice between attendings and fellows. CONCLUSIONS: Iatrogenic meningitis and spinal headache are preventable complications of dural puncture that neuroradiologists can minimize by conforming to procedural guidelines. Wearing face masks and using noncutting spinal needles will reduce patient morbidity and lower hospitalization costs associated with procedural complications.

Clinical usefulness of CT-myelogram comparing with the MRI in degenerative cervical spinal disorders: is CTM still useful for primary diagnostic tool?

STUDY DESIGN: A radiographic review of 50 patients (29 radiculopathy and 21 myelopathy) who had undergone the anterior cervical discectomy and fusion was performed by 3 observers retrospectively. OBJECTIVE: To compare the accuracy between magnetic resonance imaging (MRI) and postmyelographic computed tomography (CTM) in degenerative cervical spine disease by assessing the degree of interobserver and intraobserver agreement. SUMMARY OF BACKGROUND DATA: The assessment of degenerative cervical spinal disease is still demanding. Now MRI is accepted as a primary diagnostic tool for degenerative cervical spine disease. Compared with MRI, usage of CTM has diminished, but it is usually reserved for the patients for whom MRI results were ambiguous or technically suboptimal. METHODS: We retrospectively reviewed MRIs and CTMs of 50 patients (29 radiculopathy and 21 myelopathy) who had undergone the anterior cervical discectomy and fusion procedure. Using an assessment scale, 3 observers examined 5 parameters: spinal canal narrowing, foraminal stenosis, bony abnormality, intervertebral disk herniation, and nerve root compression. The degree of severity was graded using a 4-point scale for each item. Intraobserver, interobserver agreement, and the accentuation of each image were analyzed. RESULTS: Intraclass correlation coefficiency statistical analysis showed moderate intraobserver agreement (Cronbach's alpha=0.63) and interobserver agreement (0.52). There was no significant difference in intraobserver, interobserver agreement between MRI (0.58) and CTM (0.57). Compared between MRI and CTM, disc abnormality and nerve root compression on MRI and foraminal stenosis and bony lesion on CTM showed better agreement. CONCLUSIONS: CTM was still useful in diagnosis of the foraminal stenosis and bony lesion comparing with MRI but showed limitation in disc abnormality and nerve root compression. So even though CTM may provide valuable additional information in difficult or ambiguous cases, it also requires universal standards and sound experience for constant and objective information.

Are C1-2 punctures for routine cervical myelography below the standard of care?

BACKGROUND AND PURPOSE: Recently, the performance of C1-2 punctures for cervical myelography was challenged in a medicolegal proceeding as being below the standard of care. We sought to examine current neuroradiologic practices and opinions on the technique. MATERIALS AND METHODS: An 11-question survey was sent to 120 program directors of neuroradiology via e-mail links regarding cervical myelography using a C1-2 puncture. Reminders were sent during a 2-month period before data were finalized. RESULTS: Eighty-five of 120 (71%) surveys were returned. In the previous year, 14.3% (12/85) of institutions had not performed a C1-2 puncture. Thirty-eight percent (32/85) had performed >or=6 in the same period. Seventy-nine percent (54/68 responding) favored a lumbar approach to cervical myelography, with 6% (4/68) having a predilection for a C1-2 puncture. Ninety-five percent (76/80 responding) thought that performing a C1-2 puncture for cervical myelography reflected the standard of care. Every institution except 1 had staff with expertise to perform C1-2 punctures, and 73% of the institutions teach their fellows the procedure. Ninety-three percent (78/84) of programs would perform a C1-2 puncture for thoracolumbar pathology if MR imaging was contraindicated and there was a contraindication such as a local wound infection precluding a lumbar puncture. Indications for a C1-2 approach included severe lumbar spinal stenosis, infection in the lumbar region, upper limit of the block to be delineated, technical issues preventing lumbar puncture, and the best assessment of the cervical region for myelographic films. CONCLUSIONS: C1-2 puncture for cervical myelography, though currently not the most frequently performed method at most institutions, continues to be practiced and is considered within the standard of care by most neuroradiology programs across the country.

Role of dynamic CT myelography in identifying the etiology of superficial siderosis.

The authors report three cases of superficial siderosis with a fluid-filled spinal canal cavity communicating with the subarachnoid space. The site of communication was identified with dynamic CT myelography and the defect was surgically repaired.

Lumbosacral myelography in dogs--a safer technique.

In search of a safer myelographic technique, we performed myelography via the lumbosacral intervertebral space. Eight dogs, in which the backflow of cerebrospinal fluid was observed, received contrast media via the lumbosacral intervertebral space. The subarachnoid contrast columns were successfully observed in 6 dogs. During and after examination, no physiological changes or neurological signs were observed. We recommend that the lumbosacral intervertebral space be selected first before implementing the conventional lumbar myelography.

Lumbopelvic lordosis and pelvic balance on repeated standing lateral radiographs of adult volunteers and untreated patients with constant low back pain.

STUDY DESIGN: Twenty volunteers and 20 patients with no prior spine surgery had two standing lateral radiographs taken, on the average, 66 months apart and 2 weeks apart, respectively. OBJECTIVES: To first determine the reliability of the measurement techniques used, and then the longitudinal variation between radiographs for the sagittal spinopelvic alignments measured in two stable populations, the one manifesting no back symptoms (volunteers) and the other showing no changes in symptoms (patients). Pelvic morphology also was assessed quantitatively, and significant correlations for the measurements were studied. SUMMARY OF BACKGROUND DATA: There are no published studies on longitudinal variation for measurements of sagittal spinal alignments in asymptomatic control subjects or untreated patients with stable back problems. It may be helpful to know not only how much variation in alignments can be expected between radiographs of the same individual, but also which measurements and measurement techniques offer the greatest clinical reliability and application. METHODS: Each patient in this study reported mechanical type low back pain that was constant in location and character as well as clinically consistent with symptomatic degenerative lumbar disc disease. Each patient and volunteer had 36-inch-long lateral radiographs taken of the entire thoracic and lumbar spine, which included the pelvis. After intervening periods of 1 to 4 weeks (patients) and 5 to 6 years (volunteers), a second radiograph was taken for comparison. Two observers made 24 different measurements on the radiographs including determinations for lumbopelvic lordosis, pelvic balance, and pelvic morphology using the pelvic radius technique. Reliabilities, longitudinal variations, and correlations for the measurements were compared. RESULTS: The most reliable measurements were for pelvic morphology, pelvic balance, and regional lumbopelvic lordosis by the pelvic radius technique. Pelvic morphology was the most constant measurement between individual radiographs. Pelvic morphology and total lumbosacral lordosis were dependent measurements that were complementary in determining total lumbopelvic lordosis. Lumbopelvic lordosis and pelvic balance also had strong correlation, whereas lumbosacral lordosis and pelvic balance were independent measurements. CONCLUSIONS: The pelvic radius technique is recommended for evaluating lordosis to the pelvis because this approach provided not only good measurement reliability on standing radiographs for lumbopelvic lordosis, but also determination of pelvic balance over the hips and the option to assess pelvic morphology quantitatively. Lumbopelvic lordosis and pelvic balance were strongly correlative. This finding, along with higher reliability and lower longitudinal variation on repeated radiographs, indicated greater clinical application for these specific measurements.

Vertebral centroid measurement of lumbar lordosis compared with the Cobb technique.

STUDY DESIGN: An observational study in which vertebral centroid measurement of lumbar lordosis, developed in this study, was used to examine lumbar curvature. The intra- and interobserver reliability of the vertebral centroid measurement of lumbar lordosis and the Cobb technique were compared. OBJECTIVES: To evaluate the reliability of a new method of measuring lumbar lordosis and to examine the changes in the lordotic curve from 0 degree to 90 degrees flexion of the trunk. SUMMARY OF BACKGROUND DATA: Several different methods are used to measure lumbar lordosis. The Cobb technique, based on measurement of vertebral endplates, is the method most frequently adopted for clinical diagnosis. However, because of the variations in the vertebral endplate architecture, the vertebral surface angle is difficult to identify. This reduces the reliability of the Cobb technique. METHODS: Lateral radiographs of 16 study participants were taken from the upright position to a trunk flexion of 90 degrees in 30 degrees increments. The lumbar lordotic curve was measured by three observers individually using two applications of the traditional Cobb technique and the vertebral centroid measurement of lumbar lordosis. RESULTS: Correlation coefficients of lumbar lordosis between the two methods ranged from 0.589 to 0.772 with participants standing upright (all P < 0.05). Interobserver reliability coefficients were 0.903 for vertebral centroid measurement of lumbar lordosis, 0.826 for Cobb (L1-L5), and 0.784 for Cobb (L1-S1), although the three measurements all revealed an excellent intraobserver reproducibility (r greater than 0.9). The vertebral centroid measurement of lumbar lordosis showed the smallest mean absolute differences between any two observers' measurements (< 1.7 degrees). CONCLUSIONS: The findings from this study indicate that the vertebral centroid measurement of lumbar lordosis is more reliable than the Cobb method for assessing lumbar lordosis. The vertebral centroid measurement of lumbar lordosis also can be used to evaluate the actual lumbar curvature in outline at various angles of trunk flexion.

Lumbar lordosis measurement. A new method versus Cobb technique.

STUDY DESIGN: A historic cross-sectional study of lumbar lordosis in 199 healthy individuals aged 1-30 years. OBJECTIVE: To evaluate the magnitude and rate of the development of the normal lumbar lordotic curve with age using two methods of measurement. SUMMARY OF BACKGROUND DATA: There is no agreement among spine physicians on the range of the normal lumbar lordotic curve. In certain conditions, such as a tethered spinal cord, a change in lordotic curve may indicate or even precede the onset of neurologic symptoms. Reliable measurements of the lumbar lordotic curve may aid in the early diagnosis and management of these conditions, before irreversible neurologic change ensues. METHODS: The lumbar lordotic curve was measured by the traditional Cobb technique and by a newly designed method, tangential radiologic assessment of lumbar lordosis. The data were subjected to the Morgan-Pitman test for correlated variances to observe which of the two methods was more reliable in measuring the magnitude and rate of change in the lumbar lordotic curve. RESULTS AND CONCLUSIONS: The rate of development of the lumbar lordotic curve appears to be nonlinear, increases during first year of life and during puberty, and reaches a plateau of approximately 50 degrees at maturity. The tangential radiologic assessment of lumbar lordosis method is more reproducible and more reliable in the lumbar lordotic curve, providing a smaller range of normal values (8 degrees-16 degrees less) than the Cobb method.

P1-latency interroot comparison enhances the validity of scalp-recorded somatosensory-evoked potentials to diagnose nerve root dysfunction in sciatica.

STUDY DESIGN: A prospective validity study was done of scalp-recorded somatosensory-evoked potentials as a diagnostic procedure to show lumbosacral radiculopathy in 100 consecutive patients with unilateral or bilateral sciatica. OBJECTIVE: To determine the validity gained by the use of P1-latency interroot comparison to show P1-latency prolongation. SUMMARY OF THE BACKGROUND DATA: The validity of scalp-recorded somatosensory-evoked potentials in diagnosing lumbosacral radiculopathy has been debated and is uncertain. METHOD: Sensory nerves representing nerve roots L4, L5, and S1 were stimulated bilaterally. Height-corrected P1-latency, two new P1-interroot comparison-based criteria, and absence of P1 were studied. The gold standard was defined as clinically-involved nerve roots with radiologic nerve root compression. The false-positive nerve root compression rate was determined, and the gold standard was corrected accordingly. Clinically relevant cut-off values were defined by multilevel likelihood ratio analysis. RESULTS: The positive and negative likelihood ratios of P1-latency prolongation were 6.79 and 0.53, respectively, for the gold standard, and 10.57 and 0.21, respectively, for the corrected gold standard. The validity was not reduced when scalp-recorded, somatosensory-evoked potentials were blinded to the radiologic results. Absence of P1 was associated to the gold standard and the corrected gold standard. Compared with the combined use of P1-latency interside difference and height-corrected latency, the combination of P1-interroot comparison and height-corrected P1-latency increased the sensitivity by 20% for the gold standard and 32% for the corrected gold standard, and when absent P1 was added, the overall sensitivity was 53% for the gold standard and 81% for the corrected gold standard. The corresponding specificity was 92%, and in asymptomatic nerve roots it was 98%. CONCLUSION: The P1-interroot comparison permits the use of scalp-recorded somatosensory-evoked potentials as a contributory "rule in" procedure in patients with sciatica.

Imaging in hydrocephalus and spinal dysraphism.

Hydrocephalus and spinal dysraphism are two commonly encountered clinical entities where imaging plays a vital role. Sonography, Computed Tomography and Magnetic Resonance Imaging are the modalities used for the evaluation of hydrocephalus. Ultrasound is useful in small infants with open fontanella, is non-invasive and can be performed at cribside. However, it has limitation in identifying the etiology. CT is the most cost effective modality in the evaluation of hydrocephalus and gives detailed anatomical information. MRI offers the added advantage of multiplanar display and can also assess stenosis/patency of CSF pathways, using phase contrast cine techniques. MRI is the modality of choice for evaluating spinal dysraphism and gives excellent information regarding contents of back mass, spinal cord status and associated anomalies like Chiari malformation. Myelography coupled with CT should be reserved for equivocal cases or in centres where MRI is not available.

Quiste hidatidico de localizacion espinal extradural a nivel toracico / Extradural hydatid cyst at thoracic spine

Se presenta el reporte de un caso clinico de un quiste hidatidico de localizacion espinal extra-dural a nivel toracico, con la presentacion clinica apariencia radiologica, el tratamiento quirurgico y la apariencia histologica de la lesion

A study and analysis of spinal canal diseases in the Black Lion Hospital by myelography.

Sixty seven lumbar and thoracic myelographic examinations were performed during the period February 1987 to September 1988. Fourteen patients (21%) had normal myelography while 53 (79%) patients had pathological findings. Spinal canal tumours accounted for the majority of complete CSF blocks (76.7%) Seventy-five per cent of the intradural tumours showed no abnormality on plain films of the vertebral column, whereas 75% of the extradural tumours had pathological findings. Dorsal (central) disc herniation was more frequent (70%) than lateral herniation with almost equal distribution at L5-S1 and L4-L5 disc spaces. Central disc herniation was more common at L4-L5 (71%). The measurement of the interpedicular distance on plain radiograph was not found to be diagnostic in our single case of spinal stenosis.