Prevalence of Traumatic Findings on Routine MRI in a Large Cohort of Professional Fighters.

BACKGROUND AND PURPOSE: Previous studies investigating MR imaging abnormalities among fighters have had small sample sizes. This investigation assessed a large number of fighters using the same conventional sequences on the same scanner. MATERIALS AND METHODS: Conventional 3T MR imaging was used to assess 499 fighters (boxers, mixed martial artists, and martial artists) and 62 controls for nonspecific WM changes, cerebral microhemorrhage, cavum septum pellucidum, and cavum vergae. The lengths of the cavum septum pellucidum and cavum vergae and the ratio of cavum septum pellucidum to the septum pellucidum lengths were assessed. RESULTS: The prevalence of nonspecific WM changes was similar between groups. Fighters had a prevalence of cerebral microhemorrhage (4.2% versus 0% for controls, P = .152). Fighters had a higher prevalence of cavum septum pellucidum versus controls (53.1% versus 17.7%, P < .001) and cavum vergae versus controls (14.4% versus 0%, P < .001). The lengths of the cavum septum pellucidum plus the cavum vergae (P < .001), cavum septum pellucidum (P = .025), and cavum septum pellucidum to the septum pellucidum length ratio (P = .009) were higher in fighters than in controls. The number of fights slightly correlated with cavum septum pellucidum plus cavum vergae length (R = 0.306, P < .001) and cavum septum pellucidum length (R = 0.278, P < .001). When fighters were subdivided into boxers, mixed martial artists, and martial artists, results were similar to those in the whole-group analysis. CONCLUSIONS: This study assessed MR imaging findings in a large cohort demonstrating a significantly increased prevalence of cavum septum pellucidum among fighters. Although cerebral microhemorrhages were higher in fighters than in controls, this finding was not statistically significant, possibly partially due to underpowering of the study.

Diffusion measures indicate fight exposure-related damage to cerebral white matter in boxers and mixed martial arts fighters.

BACKGROUND AND PURPOSE: Traumatic brain injury is common in fighting athletes such as boxers, given the frequency of blows to the head. Because DTI is sensitive to microstructural changes in white matter, this technique is often used to investigate white matter integrity in patients with traumatic brain injury. We hypothesized that previous fight exposure would predict DTI abnormalities in fighting athletes after controlling for individual variation. MATERIALS AND METHODS: A total of 74 boxers and 81 mixed martial arts fighters were included in the analysis and scanned by use of DTI. Individual information and data on fight exposures, including number of fights and knockouts, were collected. A multiple hierarchical linear regression model was used in region-of-interest analysis to test the hypothesis that fight-related exposure could predict DTI values separately in boxers and mixed martial arts fighters. Age, weight, and years of education were controlled to ensure that these factors would not account for the hypothesized effects. RESULTS: We found that the number of knockouts among boxers predicted increased longitudinal diffusivity and transversal diffusivity in white matter and subcortical gray matter regions, including corpus callosum, isthmus cingulate, pericalcarine, precuneus, and amygdala, leading to increased mean diffusivity and decreased fractional anisotropy in the corresponding regions. The mixed martial arts fighters had increased transversal diffusivity in the posterior cingulate. The number of fights did not predict any DTI measures in either group. CONCLUSIONS: These findings suggest that the history of fight exposure in a fighter population can be used to predict microstructural brain damage.

Pedicle marrow signal hyperintensity on short tau inversion recovery- and t2-weighted images: prevalence and relationship to clinical symptoms.

BACKGROUND AND PURPOSE: Lumbar pedicle marrow hyperintense signal on T2- and STIR-weighted images is not an uncommon finding. We hypothesize that these marrow signal intensity changes and their behavior within the pedicle are associated with clinical symptoms and that their improvement or resolution correlates with clinical improvement. We investigated the prevalence of these pedicle marrow changes, associated morphologic abnormalities, and the relationship to symptoms over time. MATERIALS AND METHODS: Prevalence was evaluated prospectively in 246 patients and retrospectively in 400 patients. To analyze the relationship between changes in signal intensity over time and symptoms, a third group of 30 patients was followed clinically for assessment of pain and functional limitation and with MR studies for 18 months or until signal intensity changes resolved. RESULTS: The prevalence of pedicle marrow hyperintensity on T2 and STIR-weighted sequences was 1.7%. Associated morphologic abnormalities were pars interarticularis and pedicle fractures and degenerative facets. In the longitudinal study, pedicle marrow signal hyperintensity on T2- and STIR-weighted images resolved in 17 patients and persisted in 5 patients. The extent, intensity, and resolution of signal intensity changes significantly related to the degree of functional limitation (P = .01). CONCLUSIONS: Resolution of pedicle marrow hyperintensity on T2 and STIR-weighted images was associated with improved functional testing and a trend toward decreased pain.

Effects of diagnostic information, per se, on patient outcomes in acute radiculopathy and low back pain.

BACKGROUND AND PURPOSE: We conducted a prospective randomized study of patients with acute low back pain and/or radiculopathy to assess the effect of knowledge of diagnostic findings on clinical outcome. The practice of ordering spinal imaging, perhaps unintentionally, includes a large number of patients for whom the imaging test is performed for purposes of reassurance or because of patient expectations. If this rationale is valid, one would expect to see a measurable effect from diagnostic information, per se. MATERIALS AND METHODS: A total of 246 patients with acute (<3 weeks) low back pain (LBP) and/or radiculopathy (150 LBP and 96 radiculopathy patients) were recruited. Patients were randomized using a stratified block design with equal allocation to either the unblinded group (MR imaging results provided within 48 hours) or the blinded group (both patient and physician blinded to MR imaging results.) After the initial MR imaging, patients followed 6 weeks of conservative management. Roland function, visual pain analog, absenteeism, Short Form (SF)-36 Health Status Survey, self-efficacy scores, and Fear Avoidance Questionnaire were completed at presentation; 2, 4, 6, and 8 weeks; and 6, 12, and 24 months. Improvement of Roland score by 50% or more and patient satisfaction assessed by Cherkin symptom satisfaction measure were considered a positive outcome. RESULTS: Clinical outcome at 6 weeks was similar for unblinded and blinded patients. Self-efficacy, fear avoidance beliefs, and the SF-36 subscales were similar over time for blinded and unblinded patients, except for the general health subscale on the SF-36. General health of the blinded group improved more than for the unblinded group (P = .008). CONCLUSIONS: Patient knowledge of imaging findings do not alter outcome and are associated with a lesser sense of well-being.

Multi-slice computed tomography as a screening tool for colon cancer, lung cancer and coronary artery disease.

Recent promising trials that use low-dose CT for the early detection of lung cancer have reinvigorated the interest in screening approaches. At the same time the development of fast image acquisition techniques, such as multislice CT, have sparked renewed interest in cardiac imaging within the radiological community. In addition to special cardiac capabilities, multislice CT has several other features such as high acquisition speed and low-dose requirements that may make this modality a universal radiological screening tool. Non-invasive disease detection is the radiologist's domain. In this paper we identify criteria for effective screening and apply these criteria to screening approaches with multislice CT when used for detection of three disease entities: colon cancer; lung cancer; and cardiovascular disease.

Degenerative disc disease and back pain.

Although MR imaging has become the most accurate test for depicting abnormal morphology, there is no agreement on the diagnostic value of morphology alone. If the natural history of a disease is not clearly understood, and if there is little consensus, within or between specialties, regarding the use of diagnostic tests, the risk of misdiagnosis is high. Degenerative disc disease is costly, debilitating, and one of the most complex conditions to manage. This article discusses symptomatology, including instability and malalignment abnormalities, intervertebral disc degeneration or herniation, spinal stenosis, and facet disease, as treated in a variety of current studies; emphasis is placed on bridging the gaps between technology, areas that deserve further research, and sound clinical judgement.

MR evaluation of epidural fibrosis: proposed grading system with intra- and inter-observer variability.

The purpose of this study is to present a grading system for the Magnetic Resonance (MR) appearance of epidural fibrosis, and to present the inter- and intra-observer variability of the system. The study population was from a randomized, double blind, controlled multicenter clinical trial evaluating the safety and effectiveness of ADCON-L anti-adhesion barrier gel, in preventing epidural fibrosis and dural adhesions following single-level unilateral laminectomy/discectomy for lumbar disc herniations. MRI of the lumbar spine was obtained, without and with gadolinium enhancement, pre-operatively and at six months post-operatively. Patients having extensive epidural scar have been shown to be 3.2 times more likely to experience recurrent radicular pain than those patients with less extensive epidural scarring. New agents have appeared in the marketplace and in clinical trials that may be used intra-operatively to modulate the presence or absence of epidural scar tissue. Given these factors, the need to accurately describe the location and amount of epidural scar tissue has assumed more pressing importance. Two readers, blinded to clinical findings and to the other reader, independently evaluated the MR examinations in 50 post-operative lumbar spine surgery patients using the previously defined categorization of epidural scar for five levels in each patient, four quadrants per level. In addition, 114 examinations were separately evaluated by the same reader for evaluation of intra-observer variability. For the purposes of epidural fibrosis identification, only the axial T1-weighted images with and without contrast were utilized. The amount of epidural fibrosis was graded on a scale of 0-4 for each quadrant at each imaging slice encompassing the operative level: 0 = no/trace scar; 1 = > 0% and < or = 25% of quadrant filled with scar; 2 = > 25% and < or = 50% of quadrant filled with scar; 3 = > 50% and < or = 75% of quadrant filled with scar; 4 = > 75% and < or = 100% of quadrant filled with scar. Each reader evaluated a total of 1000 epidural quadrants for the inter-observer assessment. The estimated kw index is 0.68 with 95% confidence interval (CI) of [0.64, 0.71]; this is substantial agreement. There were a total of 2,280 quadrants evaluated overall for the intra-observer assessment. The estimated kw index is 0.94 with 95% CI of [0.93, 0.95]; this is almost perfect agreement. Substantial intra-observer and near perfect inter-observer agreement was achieved for evaluation of epidural scar using a relatively simple, semi-quantitative approach to the T1-weighted axial MR images. A standard grading system for epidural scar is proposed.

Assessment of the efficacy of noninvasive screening for patients with asymptomatic neck bruits.

BACKGROUND AND PURPOSE: Several recent clinical trials have shown that endarterectomy is efficacious in patients with asymptomatic carotid artery stenosis. The purpose of this study was to evaluate the effectiveness of various test strategies for screening and diagnosing carotid artery disease. METHODS: We constructed a model of the natural history of carotid artery disease using literature-based estimates of the prevalence and incidence of carotid artery stenosis and associated morbidity and mortality. Markov cohort simulation was used to estimate the mean quality-adjusted life years and monetary costs associated with various management strategies. RESULTS: Screening is cost-effective in the baseline model. Key parameters affecting the efficacy of screening are prevalence of operable lesions, benefit of surgery, surgical complication rates, quality of life with stroke, rate of stenosis progression, and excess morbidity and mortality. CONCLUSIONS: Asymptomatic patients with carotid bruits may benefit from screening if the prevalence rate is > or = 20%, the benefits and risks associated with surgery are similar to those observed in the Asymptomatic Carotid Atherosclerosis Study, and the quality of life with stroke is considerably lower than the quality of life without stroke. Ultrasound followed by three-dimensional time-of-flight MR angiography, if indicated, is a promising test strategy.

MR imaging of vertebral osteomyelitis revisited.

OBJECTIVE: The purpose of this study was to reevaluate previously reported MR imaging findings for vertebral osteomyelitis that include decreased signal intensity in the disk and adjacent vertebral bodies on T1-weighted images, increased signal intensity in the disk and adjacent vertebral bodies on T2-weighted images, loss of endplate definition on T1-weighted images, and contrast enhancement of the disk, adjacent vertebral bodies, and involved paraspinal and epidural soft tissues. MATERIALS AND METHODS: Medical records, radiographs, and MR scans of 37 patients with vertebral osteomyelitis with 41 levels of involvement were reviewed for agreement with reported MR imaging findings. RESULTS: Ninety-five percent of the levels (39/41) showed decreased vertebral body signal intensity on T1-weighted images; 95% (39/41) had loss of endplate definition; 95% (37/39) had increased disk signal intensity on T2-weighted images; and 56% (22/39) had increased vertebral body signal intensity on T2-weighted images. Eighty-five percent of the levels (35/41) and 84% of patients (31/37) had both signal intensity changes of the vertebral body on T1-weighted images and signal intensity changes of the disk on T1-and T2-weighted images. Only 46% of the levels (19/41) and 49% of patients (18/37) had both vertebral body and disk changes on T1- and T2-weighted images. Contrast enhancement of the disk and vertebral body was seen in 94% of patients (17/18). Ring enhancement of paraspinal and epidural processes was found to correlate at surgery with abscess, and homogeneous enhancement was found to correlate with phlegmon. CONCLUSION: Hypointense signal intensity in the vertebral body on T1-weighted images, abnormal disk signal intensity on both T1- and T2-weighted images, and contrast enhancement are the findings that indicate spinal infection most reliably.

A randomized comparison of iodixanol and iohexol in adult intracranial computed tomography scanning.

RATIONALE AND OBJECTIVES: Nonionic iodinated contrast media have proved effective for computed tomography (CT) of the head and have demonstrated greater tolerability than their ionic counterparts. Iodixanol is a new nonionic agent with the added attribute of being isosmolar to blood and having less than half the osmolality of iohexol. Phase I safety, tolerance, and pharmacokinetic studies have indicated that iodixanol may be associated with fewer adverse effects than iohexol while providing equivalent diagnostic information. METHODS: We compared the safety and efficacy of iodixanol at 270 mg I/ ml (IOD-270) and at 320 mg I/ml (IOD-320) with iohexol 300 mg I/ml (IOH-300). RESULTS: No statistically significant differences in the quality of images or in the occurrence of adverse events were found among the three treatment groups. Pairwise comparisons of injection-associated discomfort revealed that significantly more patients in the IOH-300 group experienced discomfort than in either the IOD-270 or IOD-320 groups. CONCLUSION: Iodixanol at 270 or 320 mg I/ml was found to be safe and effective when administered intravenously at a volume of 100 ml for intracranial CT scans in adult patients.

Association between peridural scar and recurrent radicular pain after lumbar discectomy: magnetic resonance evaluation. ADCON-L European Study Group.

The purpose of this study was to investigate the presence of any correlation between recurrent radicular pain during the first six months following first surgery for herniated lumbar intervertebral disc and the amount of lumbar peridural fibrosis as defined by MR imaging. 197 patients who underwent first-time single-level unilateral discectomy for lumbar disc herniation were evaluated in a randomized, double-blind, controlled multicenter clinical trial. Clinical assessments, performed by physicians blinded to patient treatment status, were conducted preoperatively and at one and six months postoperatively. The enhanced MR images of the operative site utilized in the analysis were obtained at six months postoperatively. Radicular pain was recorded by the patient using a validated visual analog pain scale in which 0 = no pain and 10 = excruciating pain. The data obtained at the 6 month time point were analyzed for an association between amount of peridural scars as measured by MR imaging and clinical failure as defined by the recurrence of radicular pain. The results showed that the probability of recurrent pain increases when scar score increases. Patients having extensive peridural scar were 3.2 times more likely to experience recurrent radicular pain than those patients with less extensive peridural scarring. In conclusion, this prospective, controlled, randomized, blinded, multicenter study has demonstrated that there is a significant association between the presence of extensive peridural scar and the occurrence of recurrent radicular pain.

Lumbar discography.

Lumbar discography has been suggested as a means of testing the lumbar disc as a source of back pain. While some clinicians believe that discography helps to identify conditions such as internal disc disruption, and to verify painful disc levels in anticipation of surgery, others find the test unproven and of questionable benefit. While the existence of internal disc disruption is itself hotly debated, Dr. Bogduk and Dr. Modic have focused on fundamental issues in formulating their opinions on the use of this modality. While both agree that prospective, controlled clinical trials are needed, Dr. Bogduk feels that the usefulness of discography has been shown and that the test provides valuable information to the clinician and the patient. Dr. Modic feels strongly that the test has no proven efficacy in improving patient outcomes, and feels, in fact, that it leads to inappropriate surgery.

The postoperative lumbar spine: enhanced MR evaluation of the intervertebral disk.

PURPOSE: To document the pattern of enhancement and morphologic changes on MR images that occur in the intervertebral disk and adjacent vertebral bodies after diskectomy and to correlate the presence of intervertebral disk enhancement with the preoperative and postoperative clinical findings. METHODS: Preoperatively, and at 3 months and 6 months after surgery, 94 adults who had first-time surgery for a herniated lumbar intervertebral disk that was associated with radiculopathy, expressed as leg symptoms or signs (with or without lower back pain), were asked to respond to a questionnaire regarding pain, were given serial physical examinations, and were examined with contrast-enhanced MR imaging. The measures of clinical outcome that were evaluated included the straight leg raise sign, radicular pain, and lower back pain. Type of disk herniation, intervertebral disk enhancement, disk space height, and degenerative end-plate changes were also assessed. RESULTS: Of the 94 patients evaluated, 19 (20%) had postoperative intervertebral disk enhancement that was not present on the preoperative study. The pattern of enhancement was remarkably consistent, with 18 of the cases showing linear enhancement within the intervertebral disk, manifested as two thin bands paralleling the end plates. End-plate enhancement was present in 7 (37%) of the 19 patients with disk enhancement. There were no significant associations between disk enhancement and specific clinical symptoms before or after surgery. CONCLUSION: Our group of asymptomatic postoperative patients had anular enhancement (curette site), disk enhancement, and vertebral end-plate enhancement on MR images without evidence of disk space infection. This finding points out the need to understand asymptomatic postoperative changes that are sequelae of surgery and not necessarily indicators of infection.

Current implications for the efficacy of noninvasive screening for occult intracranial aneurysms in patients with a family history of aneurysms.

Although the technology exists for accurate noninvasive screening for intracranial aneurysms, the efficacy of screening depends on several key parameters of the natural history of aneurysms. Recent studies suggest that the prevalence of intracranial aneurysms may reach 20% in the subpopulation of patients with a family history of these lesions; other key parameters are less certain. The authors investigated factors that impact the efficacy of screening to establish interim guidelines. Three plausible models for the natural history of aneurysms were constructed. For each model the monetary cost of screening and the average gain in life expectancy were computed for a range of screening ages and prevalence rates. It is shown that the efficacy of screening depends on the pattern of aneurysm rupture. If aneurysms develop and rupture rapidly, then screening has no benefit. On the other hand, if aneurysms remain at risk for some time after formation, then screening may improve average life expectancy depending on when it occurs. The authors recommend that patients with a positive family history of aneurysms who are 30 years of age or younger be screened. This recommendation is based on the belief that the gains attributable to screening, assuming a constant rupture rate, outweigh the losses attributable to screening using a decreasing rupture rate model.

Interobserver and intraobserver variability in interpretation of lumbar disc abnormalities. A comparison of two nomenclatures.

STUDY DESIGN: A double-blind prospective study was used to measure interobserver and intraobserver variability when interpreting lumbar spine magnetic resonance imaging studies of disc abnormalities. OBJECTIVES: To evaluate reader consistency when interpreting disc extension beyond the interspace, and assess the effect of two distinct nomenclatures on reader consistency. SUMMARY OF BACKGROUND DATA: Interobserver and intraobserver variability in interpretation of lumbar disc abnormalities is an important consideration in analyzing the technical efficacy of an imaging modality. However, this has not been well measured (particularly for standardized nomenclature). METHODS: Magnetic resonance imaging studies of the lumbar spine performed prospectively in 98 asymptomatic volunteers, and an additional 27 selected studies from symptomatic patients, were read blindly by two experienced neuroradiologists, using two separate nomenclatures. Only the discs were evaluated (625 interspaces). Nomenclature I was normal, bulge, herniation. Nomenclature II was normal, bulge, protrusion, extrusion. Intraobserver and interobserver variation were measured with Kappa statistic analysis. RESULTS: Interobserver agreement was 80% for both nomenclatures with a Kappa statistic of 0.58. Intraobserver agreement was 86% for each reader, with a Kappa statistic of 0.71 and 0.69, respectively. The most common disagreement was for normal versus bulge. The next most common disagreement (5-6%) was for bulge versus herniation (or protrusion in Nomenclature II). Herniation was read in 23% of the asymptomatic subjects. Using Nomenclature II, protrusion was seen in 27% of these subjects. Extrusion was read in only two asymptomatic subjects. CONCLUSIONS: Experienced readers using standardized nomenclature showed moderate to substantial agreement with interpreting disc extension beyond the interspace on magnetic resonance imaging.

Contrast-enhanced MR imaging in acute lumbar radiculopathy: a pilot study of the natural history.

PURPOSE: To prospectively study clinical findings and contrast material-enhanced magnetic resonance (MR) images over time in patients with acute lumbar radiculopathy. MATERIALS AND METHODS: Twenty-five patients underwent physical examination and MR imaging at presentation, 6 weeks, and 6 months. Initial symptoms and clinical course were correlated with type, size, location, and enhancement of disk herniations. RESULTS: Eighteen patients had a herniated nucleus pulposus (HNP) at one or more levels, two had synovial cysts and stenosis, and five had normal findings. Patients with an HNP had marginally more severe neurologic symptoms than did patients without an HNP (P = .07) at presentation. Twenty-two patients completed the 6-week examinations and 14 patients the 6-month examinations; three patients were eliminated from the study after surgical treatment. Among HNPs larger than 6 mm, substantial reduction in size was noted in 36% at 6 weeks and in more than 60% at 6 months after presentation. CONCLUSION: Agreement between clinical and MR findings for level and side of HNP and radicular symptoms was excellent. There was no correlation of pain and disability with disk size, behavior, or type.

Hyperintense disks on T1-weighted MR images: correlation with calcification.

PURPOSE: To determine if calcification in the intervertebral disk is associated with hyperintensity on T1-weighted spin-echo magnetic resonance (MR) images. MATERIALS AND METHODS: Sagittal T1-weighted MR images that showed one or more hyperintense intervertebral disks and correlative computed tomographic (CT) scans, plain radiographs, or both, were obtained in 11 patients retrospectively and in 43 patients prospectively. Six patients underwent MR imaging with a fat-suppression technique. Histologic analysis of two disks was performed. RESULTS: Absence of calcification was associated with disks that were isointense relative to normal disks (P < .001), mild to moderate calcification was associated with hyperintense disks (P < .001 and P = .004 [two readers]), and both mild to moderate and marked calcifications were associated with hypointense disks (P < .001). Fat suppression resulted in a decrease in hyperintense signal in two patients. CONCLUSION: The results indicate that hyperintensity is associated with calcification. In the absence of clinical findings that suggest other causes, hyperintense disks are suggestive of degenerative disk disease.