Search

OBJECT Screening, management, and follow-up of Grade 3 and 4 blunt carotid artery injuries (BCAIs) remain controversial. These high-grade BCAIs were analyzed to define their natural history and establish a rational management plan based on lesion progression and cerebral infarction. METHODS A retrospective review of a prospectively maintained database of all blunt traumatic carotid and vertebral artery injuries from August 2003 to April 2013 was performed, and Grade 3 and 4 BCAIs were identified. The authors define Grade 3 injuries as stenosis of the vessel greater than 50%, or the development of a pseudoaneurysm, and Grade 4 injuries as complete vessel occlusion. Demographic information, imaging findings, number of images obtained per individual, length of radiographic follow-up examination, radiographic outcome at end of follow-up period, treatment(s), and documentation of ischemic stroke or transient ischemic attack (TIA) were recorded. RESULTS Fifty-three Grade 3 BCAIs in 44 patients and 5 Grade 4 BCAIs in 5 patients were identified and had available follow-up information. The mean follow-up duration for Grade 3 BCAIs was 113 days, and the mean follow-up for Grade 4 BCAIs was 78 days. Final imaging of Grade 3 BCAIs showed that 53% of cases were radiographically stable, 11% had resolved, and 11% were improved, whereas 25% had radiographically worsened. In terms of treatment, 75% of patients received aspirin (ASA) alone, 5% received various medications, and 2% received no treatment. Eighteen percent of the patients in the Grade 3 BCAI group underwent endovascular intervention, and in all of these cases, treatment with ASA was continued after the procedure. Final imaging of the Grade 4 BCAIs showed that 60% remained stable (with persistent occlusion), whereas the remaining arteries improved (with recanalization of the vessel). All patients in the Grade 4 BCAI follow-up group were treated with ASA, although in 1 patient treatment was transitioned to Coumadin. There were 3 cases of cerebral infarction that appeared to be related to Grade 3 BCAIs (7% of 44 patients in the Grade 3 group), and 1 case of stroke that appeared to be related to a Grade 4 BCAI. All identified cases of stroke developed soon after hospital admission. CONCLUSIONS Although the posttraumatic cerebral infarction rate may be overestimated, the results of this study suggest that the Grade 3 and 4 BCAIs carry the highest stroke risk of the blunt cerebrovascular injuries, and those infarctions were identified on or shortly after hospital admission. Despite a 40% recanalization rate in the Grade 4 BCAI group and an 89% rate of persistent pseudoaneurysm in the Grade 3 BCAI group, follow-up imaging showed progressive worsening without radiographic improvement in only a small number of patients, and these findings alone did not correlate with adverse clinical outcome. Follow-up protocols may require amending; however, further prospective studies are needed to make conclusive changes as they relate to management.

Object Osteopetrosis is a rare congenital metabolic bone disease. There are very few reports in the literature associating cerebellar tonsillar herniation (CTH) and hydrocephalus requiring neurosurgical attention. The authors present cases of osteopetrosis requiring neurosurgical intervention from their practice and offer a detailed account of the literature. Methods A retrospective review was conducted at the authors' institution, and all children with osteopetrosis requiring neurosurgical attention were identified. Medical charts and radiographic studies were reviewed. Data including age at presentation, sex, symptoms at presentation, age at follow-up, the presence of any neurological comorbidities, and surgical procedures performed were recorded. Results Four patients were identified as having osteopetrosis requiring neurosurgical attention at the authors' institution between January 1, 2005, and January 1, 2014. There were 3 females and 1 male with an average age at presentation of 11.1 years; patients were observed for a mean of 4.4 years. All of the patients were identified as harboring jugular foraminal stenosis and CTH. Seventy-five percent of these patients developed hydrocephalus, and in those cases a triventricular pattern of dilation was noted. One patient developed syringomyelia. Three of the 4 patients underwent neurosurgical procedures. Cerebrospinal fluid diversion was performed in 2 patients via a ventriculoperitoneal shunt in one case and an endoscopic third ventriculostomy (ETV) in the other. The former patient required a proximal revision at 2 years for bony overgrowth at the site of the bur hole. Two patients underwent a suboccipital decompression. In patients undergoing CSF diversion, there was improvement in ventricle size. Conclusions Variable degrees of hindbrain crowding and/or CTH are mentioned throughout the literature, suggesting that this entity is nearly always present in this patient population. The progressive triventricular hydrocephalus seen in these cases results from a complex combination of both communicating and noncommunicating pathology, which may depend on the type of osteopetrosis, age at presentation, and the presence and degree of venous collateralization, and it appears that the hydrocephalus is more prevalent and more likely to be treated in infants and in the younger, school-aged population. The acquired hindbrain fullness in conjunction with the triventricular pattern of hydrocephalus has kept the authors enthusiastic regarding the use of ETV in these complicated cases.

Evidence is emerging that isolated traumatic subarachnoid hemorrhage (ITSAH) may be a milder form of traumatic brain injury (TBI). If true, ITSAH may not benefit from intensive care unit (ICU) admission, which would, in turn, decrease resource utilization. We conducted a retrospective review of all TBI admissions to our institution between February 2010 and November 2012 to compare the presentation and clinical course of subjects with ITSAH to all other TBI. We then performed descriptive statistics on the subset of ITSAH subjects presenting with a Glasgow Coma Score (GCS) of 13–15. Of 698 subjects, 102 had ITSAH and 596 had any other intracranial hemorrhage pattern. Compared to all other TBI, ITSAH had significantly lower injury severity scores (p

The objective of our study was to determine whether the CT scout view should be routinely reviewed by comparing diagnostic information on the scout view with that provided by the correlative CT study.Two radiologists blinded to history and CT findings reviewed retrospectively 2032 scout views. All cases with major findings (defined as any abnormality that would prompt additional diagnostic tests or require management) were correlated with the CT study, other imaging study, or medical record when necessary by a third radiologist to determine the validity of the scout view finding and whether the finding was identifiable on the current CT study.Major findings were identified in 257 (13%, reader 1) and 436 (23%, reader 2) of cases. Most major findings were confirmed (69-78%) or refuted (13-16%) by the CT study. However, 15 (6%, reader 1) and 48 (11%, reader 2) of the major findings were not included in the CT FOV, of which five (2%, reader 1) and 21 (5%, reader 2) constituted a missed pathologic finding. The most common one was cardiomegaly detected on a nonchest CT scout view. Additional pathologic findings included fracture, metastasis, avascular necrosis or subluxation of the humeral head, dilated bowel, and thoracic aortic dilatation. The most common false-positive finding was cardiomegaly.In a small percentage of cases, review of the CT scout view will disclose significant pathologic findings not included in the CT FOV. The results of this study support the routine inspection of the scout view, especially for the detection of pathologic findings in anatomic regions not imaged by CT.

Endometriosis is a common disease; however, ectopic mullerian tissue within the spine is a rare entity with the potential for producing significant neurological compromise. There are several postulated etiologies for this phenomenon, and only a few case reports are available in the world literature. Knowledge of this rare phenomenon is of paramount importance, since early diagnosis can lead to lessened neurological morbidity. In this manuscript, we present a case report, discuss gynecological and neurosurgical perspectives relating to the treatment strategies for managing this entity, and propose an alternative explanation for such an occurrence from a neurogenetic standpoint. We present a case of spinal mullerianosis within the conus medullaris which was managed symptomatically for several years with an intracystic drain and subcutaneous reservoir. Over the years, it became clear that there was a cyclical presentation to her clinical malady, which at times was severe. Ultimately, she required surgical resection which aided in her diagnosis and subsequent treatment. Intraspinal mullerianosis is a rare location for an otherwise common disease in women and has the potential to create significant neurological morbidity by creating a mass lesion. Although the exact etiology remains unclear, the histogenic theories of embryologic origin appear most plausible. Treatment strategies for this condition may include hormonal therapy, obstetrical surgery, or open spinal surgery. This unusual and poorly understood disease should be considered in the differential diagnosis for intraspinal lesions presenting with hemorrhage in the clinical context of cyclical neurological symptoms.

Object The optimal management of Chiari malformations in the setting of craniosynostosis is not well established. In this report the authors describe their outcomes with the combined technique of simultaneous suboccipital decompression (SOD) during posterior cranial vault remodeling (PCVR). Methods A retrospective review was performed of all patients undergoing PCVR and simultaneous SOD. Demographic data, diagnosis, imaging studies, operative intervention, and clinical follow-up were evaluated. Results Thirty-four patients were identified as having undergone a simultaneous PCVR/SOD for Chiari malformation associated with craniosynostosis. Eighty-eight percent of these patients had syndromic, multisutural craniosynostosis, and the remaining patients had unilateral lambdoid craniosynostosis. There were no postoperative complications as a direct result from this combined procedure. Two patients required a subsequent direct approach for decompression of the Chiari malformation. The interval between these subsequent surgeries was 3 years and 19 months. Conclusions Chiari malformations are commonly associated with syndromic, complex craniosynostosis and isolated lambdoid craniosynostosis. In appropriately selected patients, a combined posterior cranial vault enlargement and SOD of the foramen magnum is associated with a low complication rate and appears to be an effective procedure.

Although intracerebral schwannomas are typically regarded as benign intracranial tumors, malignancy and recurrence have been reported among patients harboring such neoplasms. The available literature consists of case reports and small series that present variable characteristics distinguishing these unusual lesions. Little advancement has been made to further the understanding and management of these tumors. The authors present 3 cases from their institution that highlight the difference between typical benign intracerebral schwannomas and histopathological variants that may portend more aggressive behavior. Also provided is a review of the literature in the hope of gaining a better understanding of these rare tumors.

Scheduled repeat head computed tomography after mild traumatic brain injury has been shown to have limited use for predicting the need for an intervention. We hypothesized that repeat computed tomography in persons with intracranial hemorrhage and a Glasgow Coma Scale (GCS) score of 13 to 15, without clinical progression of neurologic symptoms, does not impact the need for neurosurgical intervention or discharge GCS scores.This prospective cohort study followed all patients presenting to our urban Level I trauma center with intracranial hemorrhage and a GCS score of 13 to 15 from February 2010 to December 2010. Subjects were divided into two groups: those in whom repeat CT scans were performed routinely (ROUTINE) and those in whom they were performed selectively (SELECTIVE) based on changes in clinical examination. CT scanning decisions were made at the discretion of the neurosurgical service attending physician.One hundred forty-five patients met the inclusion criteria (ROUTINE, n = 92; SELECTIVE, n = 53). Group demographics, including age, sex, and presenting GCS score were not significantly different. Of SELECTIVE patients, six (11%) required a repeat head computed tomography for a neurologic change, with one having a radiographic progression of hemorrhage (16%) versus 26 (28%) of 92 in the ROUTINE group showing a radiographic progression. No patient in either group required medical or neurosurgical intervention based on repeat scan. The number of CT scans performed differed between the two groups (three scans in ROUTINE vs. one scan in SELECTIVE, p0.001), as did the intensive care unit (2 days vs. 1 day, p0.001) and hospital (5 days vs. 2 days, p0.001) lengths of stay. Discharge GCS score was similar for both groups (15 vs. 15, p = 0.37). One death occurred in the SELECTIVE group, unrelated to intracranial findings. The negative predictive value of a repeat CT scan leading to neurosurgical intervention with no change in clinical examination was 100% for both groups.A practice of selective repeat head CT scans in patients with traumatic brain injury admitted with a GCS score of 13 to 15 decreases use of the test and is associated with decreased hospital length of stay, without impacting discharge GCS scores.Diagnostic study, level II.

Recent software developments enable interactive, real-time axial, 2D and 3D CT display on an iPad by cloud computing from a server for remote rendering. The purpose of this study was to compare radiologists' interpretative performance on the iPad to interpretation on the conventional picture archive and communication system (PACS). Fifty de-identified contrast-enhanced CT exams performed for suspected pulmonary embolism were compiled as an educational tool to prepare our residents for night call. Two junior radiology attendings blindly interpreted the cases twice, one reader used the PACS first, and the other interpreted on the iPad first. After an interval of at least 2 weeks, the cases were reinterpreted in different order using the other display technique. Sensitivity, specificity, and accuracy for identification of pulmonary embolism were compared for each interpretation method. Pulmonary embolism was present in 25 patients, ranging from main pulmonary artery to subsegmental thrombi. Both readers interpreted 98 % of cases correctly regardless of display platform. There was no significant difference in sensitivity (98 vs 100 %, p = 1.0), specificity (98 vs 96 %, p = 1.0), or accuracy (98 vs 98 %, p = 1.0) for interpretation with the iPad vs the PACS, respectively. CT interpretation on an iPad enabled accurate identification of pulmonary embolism, equivalent to display on the PACS. This mobile device has the potential to expand radiologists' availability for consultation and expedite emergency patient management.

Gastric pneumatosis is rare, with causes ranging from benign to lethal. The purpose of this pictorial essay is to present a series of cases of gastric pneumatosis, review the causes, and demonstrate how computed tomography (CT) can help guide management. A range of primary gastric pathology can cause air in the wall of the stomach. However, gastric pneumatosis may reflect intraabdominal pathology arising from other hollow viscera, with indicators of the extragastric etiology on CT.

SummaryObjectiveTo determine whether computer-based analysis can detect features predictive of osteoarthritis (OA) development in radiographically normal knees.MethodA systematic computer-aided image analysis method weighted neighbor distances using a compound hierarchy of algorithms representing morphology (WND-CHARM) was used to analyze pairs of weight-bearing knee X-rays. Initial X-rays were all scored as normal Kellgren–Lawrence (KL) grade 0, and on follow-up approximately 20 years later either developed OA (defined as KL grade=2) or remained normal.ResultsThe computer-aided method predicted whether a knee would change from KL grade 0 to grade 3 with 72% accuracy (P

The authors report their experience using preoperative chest radiography and intraoperative ultrasonography for percutaneous positioning of the distal end of the catheter when placing ventriculoatrial (VA) shunts in patients with hydrocephalus. The distal portion of VA shunt catheters were percutaneously placed into the internal jugular vein with the aid of intraoperative ultrasonography in 14 consecutive adults. In all cases, the technique was easy, there were no postoperative complications, and postoperative chest radiography demonstrated good positioning of the distal catheter tip. One patient presented with a shunt infection and needed a shunt replacement. The authors therefore conclude that percutaneous placement of a VA shunt under preoperative radiographic guidance and ultrasonographic monitoring is a safe, effective, and reliable technique that is simple to learn.

We describe a method for automated detection of radiographic osteoarthritis (OA) in knee X-ray images. The detection is based on the Kellgren-Lawrence (KL) classification grades, which correspond to the different stages of OA severity. The classifier was built using manually classified X-rays, representing the first four KL grades ( normal, doubtful, minimal, and moderate). Image analysis is performed by first identifying a set of image content descriptors and image transforms that are informative for the detection of OA in the X-rays and assigning weights to these image features using Fisher scores. Then, a simple weighted nearest neighbor rule is used in order to predict the KL grade to which a given test X-ray sample belongs. The dataset used in the experiment contained 350 X-ray images classified manually by their KL grades. Experimental results show that moderate OA (KL grade 3) and minimal OA (KL grade 2) can be differentiated from normal cases with accuracy of 91.5% and 80.4%, respectively. Doubtful OA (KL grade 1) was detected automatically with a much lower accuracy of 57%. The source code developed and used in this study is available for free download at www.openmicroscopy.org.

Rheumatoid arthritis (RA), a systemic auto-immune disease affecting 0.5–1% of the population worldwide, is characterized by chronic joint inflammation and, in severe cases, joint erosions (1). Although the mechanisms of initiation and propagation of RA remain incompletely defined, autoimmunity and inflammatory effector pathways appear to play important pathogenetic roles. The notable efficacy of tumor necrosis factor (TNF) inhibitors has established that TNFα plays a central role in RA, and the therapeutic effects of rituximab and abatacept strongly indicate roles for B cells and T cells, respectively (2,3). Although the specific autoantigens that drive B cells and T cells in RA remained elusive for decades, recent advances have identified protein citrullination as a primary focus of the RA-specific autoantibody response (4). Citrulline is generated posttranslationally by the deimination of arginine, and autoantibodies in RA recognize various naturally citrullinated proteins (including fibrin, vimentin, and filaggrin), as well as cyclic citrullinated peptides (CCPs) derived from them (5-7). Together with the extraordinary specificity (90–99%) of anti-CCP antibodies in RA (8,9), the observation that anti-CCP antibodies are frequently present early in the disease process and often precede development of the diagnostic phenotype (10-13) strongly suggests that these antibodies are markers of the specific events that initiate autoimmunity in RA. The citrullination reaction is catalyzed by a family of enzymes known as peptidyl arginine deiminases (PADs). There are 5 isoforms (14), differentially expressed in various cells. PAD type 4 (PAD-4) has received particular attention in RA, since it is expressed in myelomonocytes, can be detected in inflamed RA synovium (14,15), and has recently been genetically associated with RA. The first group to describe the genetic association of PADI4 variants with RA defined 2 common haplotypes of the PADI4 gene segregated by 4 exonic single-nucleotide polymorphisms (SNPs) in linkage disequilibrium. These 2 haplotypes were designated “susceptible (haplotype 2)” or “nonsusceptible (haplo-type 1)” based on their relative frequency in a group of Japanese patients with RA versus controls (16). The odds ratio (OR) for association of the susceptibility haplotype with RA was 1.4. In several other populations, similar associations of PADI4 susceptibility haplotypes with RA were observed, although the magnitude of the effect was lower (17-20). In some studies, no association of PADI4 genotype with RA was observed (21-23). Suzuki et al showed a modest increase in RNA stability for the susceptibility haplotype, and proposed that the genetic effect of PADI4 is mediated through increased PAD-4 levels and activity, with enhanced citrullination and increased levels of anti-CCP antibodies (16). Significant direct support for this model is still lacking, prompting us to explore whether additional mechanisms might mediate some of the genetic effect of PADI4. We demonstrate here that autoantibodies against PAD-4 protein are a highly specific marker of RA. In a cross-sectional cohort of RA patients, these antibodies were independently associated with a more severe RA phenotype, characterized by worse joint damage and erosions. Notably, anti–PAD-4 autoantibodies were associated with the PADI4 susceptibility haplotype (OR 2.59), particularly with the heterozygous diplotype (OR 4.02). Interestingly, the epitopes recognized by anti–PAD-4 antibodies include the N-terminal region of PAD-4 containing the polymorphisms associated with RA susceptibility. Taken together, the specificity of the antibody response for the polymorphic N-terminal region of PAD-4, the magnitude of the association of autoantibody with susceptibility genotype, and the association of the strongest anti–PAD-4 autoantibody responses with RA severity are striking. They implicate unique PAD-4 structure and/or function in the generation of a PAD-4–specific immune response and, potentially, the downstream augmentation of joint damage in RA.

OBJECT Proper screening, management, and follow-up of Grade 1 and 2 blunt carotid artery injuries (BCIs) remains controversial. These low-grade BCIs were analyzed to define their natural history and establish a rational management plan based on lesion progression and cerebral infarction. METHODS A retrospective review of a prospectively maintained database of all blunt traumatic carotid and vertebral artery injuries treated between August 2003 and April 2013 was performed and Grade 1 and 2 BCIs were identified. Grade 1 injuries are defined as a vessel lumen stenosis of less than 25%, and Grade 2 injuries are defined as a stenosis of the vessel lumen between 25% and 50%. Demographic information, radiographic imaging, number of imaging sessions performed per individual, length of radiographic follow-up, radiographic outcome at end of follow-up, treatment(s) provided, and documentation of ischemic stroke or transient ischemic attack were recorded. RESULTS One hundred seventeen Grade 1 and 2 BCIs in 100 patients were identified and available for follow-up. The mean follow-up duration was 60 days. Final imaging of Grade 1 and 2 BCIs demonstrated that 64% of cases had resolved, 13% of cases were radiographically stable, and 9% were improved, whereas 14% radiographically worsened. Of the treatments received, 54% of cases were treated with acetylsalicylic acid (ASA), 31% received no treatment, and 15% received various medications and treatments, including endovascular stenting. There was 1 cerebral infarction that was thought to be related to bilateral Grade 2 BCI, which developed soon after hospital admission. CONCLUSIONS The majority of Grade 1 and 2 BCIs remained stable or improved at final follow-up. Despite a 14% rate of radiographic worsening in the Grade 1 and 2 BCIs cohort, there were no adverse clinical outcomes associated with these radiographic changes. The stroke rate was 1% in this low-grade BCIs cohort, which may be an overestimate. The use of ASA or other antiplatelet or anticoagulant medications in these low-grade BCIs did not appear to correlate with radiographic injury stability, nor with a decreased rate of cerebral infarction. Although these data suggest that these Grade 1 and 2 BCIs may require less intensive radiographic follow-up, future prospective studies are needed to make conclusive changes related to treatment and management.

Pathologic fracture is a significant problem for individuals with metastatic bone disease. Current guidelines for prophylactic internal fixation are neither reliable nor easily applied. The purpose of this study was to validate dual-energy X-ray absorptiometry (DXA) as an accurate method for estimating torsional bone strength of diaphyseal bone with endosteal lytic lesions. Endosteal lesions of varying sizes were simulated in the diaphyses of 12 adult cadaveric femurs. Unaltered contralateral femurs served as matched controls. Machined lesions ranged from 3 to 6.5 cm in length, 1 to 3 cm in width, 15 to 48 cm2 in elliptical area, with 10% to 100% removal of the cortical thickness. Morphology and density data obtained from DXA images were used to estimate torsional strength. All femora were mechanically tested to failure in torsion. Physically measured torsional strength was not significantly correlated to lesion elliptical area (r = 0.542, p > 0.05) or percentage cortical thickness removed (r = 0.257, p > 0.05). Measured torsional strength was significantly correlated to DXA-based torsional strength estimates (r = 0.855, p

Phase contrast microscopy, using an atomic force microscope, is used to detect and quantify changes in composition across polymer nanocomposites and molecularly thick lubricated surfaces. The technique takes advantage of the contrast in viscoelastic (viscous energy dissipation) properties of the different materials across the surface. Some materials, especially polymers, are found to display viscoelastic behavior. For such materials, the strain response lags the stress by a phase angle that is characteristic of the material. In tapping (or intermittent contact) mode, phase angle contrast is found to be highly dependent on vibration amplitude and mean tip-to-sample distance (setpoint). Phase angle contrast seems to be a stronger function of viscoelastic properties at relatively high vibration amplitude and low mean tip-to-sample distance. In this regime the effects of sample deformation, and thus viscoelastic properties, are dominant. In these contrast images, low phase angle corresponds to materials with low viscoelastic properties. This technique was used to find fairly reproducible phase angle contrast for polyethylene terephthalate (PET) films with embedded ceramic particles, metal particle (MP) magnetic tape, and Si(1 0 0) with a nonuniform Z-15 lubricant film. Very little correlation is found between phase angle images and friction force images for PET films with embedded ceramic particles and MP tape; phase angle images give information that cannot be obtained from topography or friction images. A numerical vibration model verifies that viscoelastic properties are dominant for high vibration amplitude and low mean tip-to-sample distance. For these conditions, the model also verifies that low phase angle corresponds to low viscoelastic properties.

Magnetic tapes, which may be modeled as three-ply laminates, exhibit transverse curvature, or cupping, as manufactured and when mechanical and hygrothermal loads are applied. Among other things, this cupping affects debris generation since it influences the contact between the flawed tape edge and head, the point where much of the debris generation occurs. This influence on debris generation is demonstrated experimentally in this study. Much more debris accumulates near the tape edge-head contact than at other contact locations. No difference in debris generation was found for two tapes with slightly different residual cupping (which is controlled during manufacturing). The target residual cupping is usually negative, which means that the tape bows out towards the tape so that the edges are farther away from the head than the center of contact is, so as to reduce contact pressure with the tape edges. However, cupping generally changes upon application of a tension and generally reduces the importance of residual cupping, which accounts for the failure to find a difference in debris generation for tapes with slightly different residual cupping. A finite element method model that uses laminate shell elements and accounts for in-plane stress stiffening, thus making it suitable for thin laminate modeling, was created. This modeling demonstrates that application of tensile and normal (used to simulate head contact) loads leads to cupping movement in the positive direction, which indicates a more severe edge contact, for an increase in front coat Young’s modulus and/or an increase in front coat thickness. The same trends hold for an increase in back coat Young’s modulus and/or an increase in back coat thickness. Modeling also demonstrates that cupping moves in the positive direction for an increase in the substrate’s Young’s modulus in the transverse direction for MP and ME tapes. An analytical model demonstrates that increases in temperature and front coat thermal expansion coefficient leads to cupping movement in the negative direction. The same trends hold for changes in relative humidity.

Wear of multiphase materials at the micro/nano-scale is important in devices such as magnetic tape and disk drives, where the read-write heads are multiphase. Differential wear, which is caused by differences in wear resistance among the heads’ phases, causes the thin-film poles to recede from the bearing surface; this is called pole tip recession (PTR). It is a problem because it increases spacing between the poles and medium, resulting in lower readback amplitude. Here, PTR in tape heads is studied to understand micro/nano-scale differential wear. Test results suggest that three-body abrasion, which leads to primarily plastic wear, is the operative wear mode. Most of the three-body abrasive particles originate from the tape surface; the alumina head-cleaning agents (HCAs) in the tape, which function as load bearing particles at the interface, are believed to be the primary abrasives. Some of the particles originate from the head. These are important if the substrate material is relatively soft. Differential wear can be reduced by choosing a substrate that is harder than the tape’s HCAs, choosing a pole material that is as close as possible to the hardness of the substrate, and lowering the thickness of the head’s thin-film region. Material hardness matching will not reduce differential wear if a substrate is chosen that is less hard than the HCAs. An analytical model that accounts for the observed wear is presented. The model shows that each of the following leads to higher differential wear: increasing the thickness of three-body particles, increasing tension, decreasing thin-film hardness, and increasing the thin-film wear coefficient. An increase in thin-film wear coefficient can be caused by an increase in thin-film thickness or an increase in the number of particles at the interface.

OBJECT Grade 3 and 4 blunt vertebral artery (VA) injuries may carry a different natural course from that of lower-grade blunt VA injuries. Proper screening, management, and follow-up of these injuries remain controversial. Grade 3 and 4 blunt VA injuries were analyzed to define their natural history and establish a rational management plan based on lesion progression and cerebral infarction. METHODS A retrospective review of a prospectively maintained database of all blunt traumatic carotid and vertebral artery injuries from August 2003 to April 2013 was performed, and Grade 3 and 4 blunt VA injuries were identified. Grade 3 injuries were defined as stenosis of the vessel greater than 50% or the development of a pseudoaneurysm, and Grade 4 injuries were defined as complete vessel occlusion. Demographic information, radiographic imaging findings, number of imaging sessions performed per individual, length of radiographic follow-up, radiographic outcome at end of follow-up, treatment(s) provided, and documentation of ischemic stroke or transient ischemic attack were recorded. RESULTS A total of 79 high-grade (Grade 3 and 4) blunt VA injuries in 67 patients were identified. Fifty-nine patients with 66 high-grade blunt VA injuries were available for follow-up. There were 17 patients with 23 Grade 3 injuries and 42 patients with 43 Grade 4 injuries. The mean follow-up duration was 58 days for Grade 3 and 67 days for Grade 4 blunt VA injuries. Repeat imaging of Grade 3 blunt VA injuries showed that 39% of injuries were radiographically stable, 43% resolved, and 13% improved, while 1 injury radiographically worsened. Repeat imaging of the Grade 4 blunt VA injuries showed that 65% of injuries were radiographically stable (persistent occlusion), 30% improved (recanalization of the vessel), and in 2 cases (5%) the injury resolved. All Grade 3 injuries that were treated were managed with aspirin or clopidogrel alone, as were the majority of Grade 4 injuries. There were 3 cerebral infarctions thought to be related to Grade 4 blunt VA injuries, which were likely present on admission. All 3 of these patients died at a mean of 13.7 days after hospital admission. No cerebral infarctions directly related to Grade 3 blunt VA injuries were identified. CONCLUSIONS The majority of high-grade blunt VA injuries remain stable or are improved at final follow-up. Despite a 4% rate of radiographic worsening in the Grade 3 blunt VA injury group and a 35% recanalization rate in the Grade 4 blunt VA injury group, there were no adverse clinical outcomes associated with these radiographic changes. No cerebral infarctions were noted in the Grade 3 group. A 7% stroke rate was identified in the Grade 4 blunt VA injury group; however, this was confined to the immediate postinjury period and was associated with 100% mortality. While these data suggest that these high-grade vertebral artery injuries may require less intensive radiographic follow-up, future prospective studies are needed to make conclusive changes related to treatment and management.

As a basis for venous thromboembolism (VTE) prophylaxis after traumatic brain injury (TBI), we have previously published an algorithm known as the Parkland Protocol. Patients are classified by risk for spontaneous progression of hemorrhage with chemoprophylaxis regimens tailored to each tier. We sought to validate this schema. In our algorithm, patients with any of the following are classified “low risk” for spontaneous progression: subdural hemorrhage ≤8 mm thick; epidural hemorrhage ≤8 mm thick; contusions ≤20 mm in diameter; a single contusion per lobe; any amount of subarachnoid hemorrhage; or any amount of intraventricular hemorrhage. Patients with any injury exceeding these are “moderate risk” for progression, and any patient receiving a monitor or craniotomy is “high risk.” From February 2010 to November 2012, TBI patients were entered into a dedicated database tracking injury types and sizes, risk category at presentation, and progression on subsequent computed tomgraphies (CTs). The cohort (n=414) was classified as low risk (n=200), moderate risk (n=75), or high risk (n=139) after first CT. After repeat CT scan, radiographic progression was noted in 27% of low-risk, 53% of moderate-risk, and 58% of high-risk subjects. Omnibus analysis of variance test for differences in progression rates was highly significant (p

Many hospitals experience one or more retained surgical item events per year, with risk of patient morbidity and medicolegal consequences. We hypothesized that the confidence and performance of the radiologist would be enhanced by prior training in retained surgical item detection and by prior exposure to commonly employed surgical instruments and devices. A training module for radiology residents was created through literature review, expert consultation, and imaging of commonly employed surgical instruments and devices. A survey assessing resident command of background knowledge, policy, and image-based retained surgical item questions was created. Additionally resident confidence for hospital policy and retained surgical item identification was assessed. A pre-module survey and confidence questionnaire were administered to first- through fourth- year residents. For one month, the training module was available online for independent review. Subsequently, a post-module survey and confidence questionnaire were completed by participants. $$T$$ tests were performed to evaluate pre- and posttest means for survey performance and confidence questions. Mean post-module survey performance significantly improved compared with pre-module performance. Mean confidence levels for ability to incidentally identify a retained surgical item on a radiograph obtained for another indication and current understanding of the institution’s policy regarding retained surgical items were also significantly increased. The knowledge base, diagnostic performance, and confidence of radiology residents were significantly enhanced by online teaching module training in retained surgical item detection.

Object Screening of blunt vertebral artery (VA) injuries has increased since research has shown that they occur at a higher incidence than originally reported. Grade 1 and 2 injuries are the most common form of blunt VA injury. Proper screening, management, and follow-up of these injuries remain controversial. In this report, imaging, progression, treatment, and outcomes of Grade 1 and 2 blunt VA injuries were analyzed to better define their natural history and to establish a rational management plan based upon their risk of progression and cerebral infarct. Methods A retrospective review of all blunt traumatic carotid artery and VA injuries from December 2003 to April 2013 was performed. For the purposes of this report, focus was given to Grade 1 and 2 VA injuries. Grade 1 injuries were defined as a vessel lumen stenosis of less than 25%, and Grade 2 injuries were defined as vessel lumen stenosis between 25% and 50%. Demographic information, radiological imaging, number of images performed per individual, length of radiological follow-up, radiological outcome at the end of follow-up, treatment provided, and documentation of stroke or transient ischemic attack were recorded. Results One hundred eighty-seven Grade 1 and 2 VA injuries in 143 patients were identified. Of these 143 patients, 120 with 152 Grade 1 or 2 blunt VA injuries were available for follow-up. The mean duration of follow-up was 40 days. Repeat imaging showed that 148 (97.4%) Grade 1 or 2 blunt VA injuries were stable, improved, or resolved on final follow-up imaging. Seventy-nine patients (66%) were treated with aspirin, whereas 35 patients (29%) received no treatment. The remaining patients were treated with other antiplatelet agents or anticoagulant medication. Neuroimaging demonstrated 2 cases (1.7%) with posterior circulation infarcts that were believed to be related to their blunt VA injuries, both of which occurred during the initial hospitalization and within the first 4 days after injury. Conclusions Although follow-up imaging showed progressive worsening without radiological improvement in only a small number of patients with low-grade blunt VA injuries, these findings did not correlate with adverse clinical outcome. The posttraumatic cerebral infarction rate of 1.7% may be overestimated, and the use of acetylsalicylic acid or other antiplatelet or anticoagulant medication did not correlate with radiological changes or rate of cerebral infarction. While these data suggest the possibility that these low-grade VA injuries may not require treatment or follow-up, future prospective studies are needed to make conclusive changes related to management.

Pole tip recession (PTR) and debris generation lead to signal loss at the head-tape interface. Accelerated tape drive experiments and measurements of head-tape spacing were conducted using heads with different slot orientations. PTR was higher for blind-slotted (slots in the direction of tape travel) heads than for transverse-slotted (slots in the direction transverse to tape travel) heads. More tape debris was found on the surface of transverse-slotted heads, but most of this debris resided in the slots rather than on the bearing surface. The slots in the transverse-slotted heads act as tape cleaners, which accounts for the large debris buildup in the slots. This leaves fewer loose debris particles at the interface for the transverse-slotted heads. Little difference was found in the head-tape spacing for the two types at the conditions used in the drive experiments. It is proposed that the greater amount of loose debris available at the interface for use in three-body abrasive wear, which is believed to ...

Problems with corrosion and wear in magnetic tape drives lead the industry to consider the use of ultra-thin diamond-like carbon (DLC) coatings for tape heads and metallic tapes. In this study, corrosion and wear tests are conducted on uncoated and coated tape-write heads and tapes. A multi-component flowing mixed gas test, known as the Battelle Class II test, and an elevated temperature & humidity test are used to accelerate corrosion. While past researchers have evaluated corrosion effects by measurement of changes in magnetic properties of tape, surface analysis is successfully used here to study corrosion products directly. Corrosion specimens are examined using optical microscopy, Auger electron spectroscopy, scanning electron microscopy, and atomic force microscopy. Functional drive tests are conducted to measure the effectiveness of DLC coatings, deposited by ion beam, via study of pole tip recession (PTR) in tape heads. Heads are shown to benefit in both corrosion resistance and in PTR resistance from the addition of DLC. In both cases, 20 nm thick coatings outperform 10 and 5 nm thick coatings. Coatings on ME tape show some limited benefit in corrosion resistance. ME tape specimens exposed in cartridges show much less evidence of corrosion than those exposed outside of cartridges. MP tape shows better corrosion resistance than uncoated and coated ME tapes.

Pole tip recession (PTR) in linear tape heads causes an increase in spacing and consequently an increase in signal loss. In this study, PTR in linear tape drives is analysed. Functional drive tests are conducted using thin-film Al2O3-TiC and Ni-Zn ferrite heads sliding against metal particle tape. Atomic force microscopy is used to measure PTR and the recession of the overcoat material used in the construction of the head. In measuring PTR, care must be taken in correctly orienting the stand-alone atomic force microscope tip with respect to the head sample. Care must also be taken in post-processing the raw stand-alone atomic force microscopy data. Based on PTR data with Al2O3-TiC and Ni-Zn ferrite heads, no significant differences exist in the PTR of Al2O3-TiC heads compared with Ni-Zn ferrite heads. In the case of the Ni-Zn ferrite head, the softer Ni-Zn ferrite substrate has mechanical properties close to those of the poles, suggesting that PTR growth should be low. However, additional third-body wear particles from the ferrite substrate result in additional pole tip wear. No significant difference is seen in the wear of Co-Zr-Ta poles and Ni-Fe poles, as they have comparable mechanical properties. No strong conclusion may be drawn about the effect of tape speed on PTR. An increase in tape tension leads to an increase in PTR. This is a result of an increase in the normal force, which causes an increase in the abrasive wear. An increase in interface contamination also leads to an increase in PTR.

The presence of tape debris at the head-tape interface can cause an increase in spacing and consequently an increase in signal loss. In this study, the generation of tape debris in linear tape drives is analysed. Functional drive tests are conducted using thin-film AlO3-TiC and Ni-Zn ferrite heads run against commercial metal particle (MP) tape. Three types of tape debris are found: magnetic particle rich, polymer rich and adherent (stain). Each type is found at a distinct location on the head surface. Optical microscopy and computerized image analysis are used both to quantify the tape debris and to find its distribution on the head. Atomic force microscopy is used to measure the thickness of adherent debris. The Al2O3-TiC sample generates more of all three types than does the Ni-Zn ferrite sample. This is probably a result of the higher hardness of Al2O3-TiC. The differential wear of Al2O3 and TiC probably accounts for the presence of adherent debris on the Al2O3-TiC head. No adherent debris can be found on the Ni-Zn ferrite head. Since the adherent debris collects near the pole tip and is difficult to remove, it potentially poses the greatest head-tape spacing problem, even though its thickness is only of the order of a few nanometres. A relationship is found between the generation of loose debris and the tape speed, tape tension and head wrap. Loose debris generation increases as the tape speed decreases and as the tape tension and head wrap increase. Its generation is found to be approximately proportional to the frictional force. Loose debris, especially the magnetic-particle-rich type, continues to be generated in abundant amounts beyond the burnishing phase for MP tape. The use of an abrasive tape leader is found to reduce the amount of debris at the interface.

Objective To describe the clinical features and familial distribution of rheumatoid arthritis (RA) in the Pima Indians. Methods From 1965 through 1990, all cases of RA as defined by the American College of Rheumatology (formerly, the American Rheumatism Association) 1987 criteria or all cases of seropositive, erosive disease as defined by the Rome criteria were identified in individuals who were age 20 years and older and were of 50% or more Pima/Tohono-O'odham heritage. Radiographs were reviewed by 2 musculoskeletal radiologists who were blinded to case status. Kinship coefficients were used to evaluate familial aggregation. Results Eighty-eight RA cases were identified from this population-based sample. Over 66% of the cases had seropositive disease, over 60% had erosive disease, and over 40% had subcutaneous nodules. Of the 88 RA cases, 40 were members of families with more than 1 RA case. The remainder were simplex cases. Conclusion In this population, clinical markers of severe RA were present in a majority of cases. The presence of familial aggregation for RA in the Pima Indians suggests underlying genetic factors in disease pathogenesis.

Objective To evaluate the familial aggregation of osteoarthritis (OA) in a cohort of healthy volunteers drawn from a community setting. Methods Hand radiographs obtained between 1978 and 1991 and bilateral standing knee radiographs obtained between 1984 and 1991 were read for changes of OA, using Kellgren-Lawrence (K-L) scales. The hand sites were distal interphalangeal (DIP) joints, proximal interphalangeal (PIP) joints, and first carpometacarpal (CMC1) joints. For each joint group, the presence of OA in at least 1 joint in a joint group, the number of affected digits in each joint group, and the sum of the K-L grade across all joints were analyzed. Polyarticular OA was recorded if there were OA findings in 2 of 3 hand joint groups plus 1 or both knees. Data from 167 families with hand radiographs, 157 families with knee radiographs, and 148 families with both hand and knee radiographs were analyzed for sib-sib correlations. Results After adjustment for age, sex, and body mass index, clinically relevant sib-sib common correlations were found for OA of the DIP, PIP, and CMC1 joints, for OA at 2 or 3 hand sites, and for polyarticular OA (r = 0.33-0.81) when OA was defined according to the number of affected joints or as the sum of the K-L grade across all joints. Conclusion These results from a cohort of volunteers drawn from a community setting and ascertained without regard to OA status demonstrate familial aggregation of OA and contribute to the evidence for heritability of OA.

Magnetic coatings are made up of either magnetic particles dispersed in a polymeric matrix or thin continuous films of magnetic material. Magnetic tape stiffness, in both the machine and transverse directions, influences the way in which tapes conform to magnetic heads in magnetic tape drives. For this reason tape stiffness plays an important role in the friction, stiction and wear characteristics of a magnetic head–tape interface. In this study, a test method for measuring bending stiffness is developed. A tape segment is pressed against a load cell to measure the change in force as a function of the tape's normal displacement. Stiffness values are obtained from load vs. displacement data and a derived analytical model for the displacement of the tape segment in terms of load and geometry. Stiffness measurements of finished tapes and tape substrates are presented. The correlation between tape stiffness in the machine and transverse directions, and read/write head contouring and edge wear, is also presented.

To determine observer variation in the detection of acetabular bone deficiencies, 42 pairs of frontal (AP) and lateral hip radiographs and CT studies for total hip arthroplasty patients obtained within an average of 4 weeks of each other were reviewed separately by five radiologists and one orthopedic surgeon. Interobserver variations were calculated for each individual reading the films using kappa values. The individual film readings were then compared with a consensus reading of the CT data. When separate observers were analyzed, agreement on plain film readings was slight to fair (av. kappa = 0.1440 +/- 0.1047). The individual observers were not able to give readings which were very consistent with the CT consensus reading, resulting in a low sensitivity (65%) and specificity (74%) for acetabular defect classification with plain radiographs. The identification of acetabular bone defects from the AP and lateral views of the hip is highly subjective and variable from observer to observer.

Objective To help define the perioperative risk related to commonly used non-aspirin NSAIDs with whole blood platelet aggregometry. Methods Twelve healthy volunteers were recruited. Two cyclooxygenase (COX)-1 inhibitors (ibuprofen and naproxen) and two COX-2 inhibitors (meloxicam and celecoxib) were administered, and daily whole blood platelet aggregometry studies were obtained until studies showed no platelet inhibition. Aspirin was studied at the conclusion of the study. Results Ibuprofen had no inhibitory effect on platelet aggregation in all women and no inhibitory effect in 83% of men at 24 hours. All platelet function had returned to normal at 48 hours. The inhibitory effect of naproxen on platelets was absent at 48 hours in 83% of the women and 50% of men. By 72 hours all platelet studies had returned to normal. Meloxicam and celecoxib did not cause any overall inhibitory effect on platelet aggregation. Conclusions Ibuprofen and naproxen have a mild inhibitory effect on platelet aggregation compared with aspirin and this effect is undetectable by 48 hours and 72 hours, respectively. Meloxicam and celecoxib show essentially no inhibitory effect on platelet aggregation. These findings suggest that there is little bleeding risk related to platelet aggregation at 24 hours in patients who take COX-2 inhibitors and at 72 hours for those who take COX-1 inhibitor medications.

BACKGROUND: Specific morphological factors contribute to the hemodynamics of the anterior communicating artery (AComA). No study has examined the role of the A2 segment on AComA aneurysm presence and rupture. OBJECTIVE: To examine the possibility that the ratio between A1 and A2 segments (A1-2 ratio) represents an independent risk factor for presence and rupture of AComA aneurysms (AComAAs). METHODS: A retrospective review of an institutional aneurysm database was performed; patients with ruptured and unruptured AComAAs were identified. Two control groups were selected: group A (posterior circulation aneurysms) and group B (patients without intracranial aneurysms or other vascular malformations). Measurements of A1 and A2 diameters were obtained from digital subtraction angiography (64.1% of 3-D rotational digital subtraction angiography), and the A1-2 ratio calculated. RESULTS: From January 2009 to April 2011, 156 patients were identified (52 AComAAs, 54 control group A, and 50 control group B). Mean age at the time of presentation was 56.09 years. Compared with both control groups, patients with AComAAs had greater A1 diameter (P < .01) and A1-2 ratio (P < .001) and smaller A2 diameter (P < .01). The A1-2 ratio correlated positively with the presence of AComAAs (P < .001). Ruptured AComAAs were smaller than unruptured ones (5.91 mm vs 9.25 mm, P = .02) and associated with a higher A1-2 Ratio (P = .02). The presence of a dominant A1 did not predict AComAA rupture (P = .15). The A1-2 ratio correlated positively with the presence of ruptured AComAAs (P = .04). CONCLUSION: A1-2 ratio correlates positively with the presence and rupture of AComAAs and may facilitate treatment decision in cases of small, unruptured AComAAs.

The optimal management of Chiari malformations in the setting of craniosynostosis is not well established. In this report the authors describe their outcomes with the combined technique of simultaneous suboccipital decompression (SOD) during posterior cranial vault remodeling (PCVR).A retrospective review was performed of all patients undergoing PCVR and simultaneous SOD. Demographic data, diagnosis, imaging studies, operative intervention, and clinical follow-up were evaluated.Thirty-four patients were identified as having undergone a simultaneous PCVR/SOD for Chiari malformation associated with craniosynostosis. Eighty-eight percent of these patients had syndromic, multisutural craniosynostosis, and the remaining patients had unilateral lambdoid craniosynostosis. There were no postoperative complications as a direct result from this combined procedure. Two patients required a subsequent direct approach for decompression of the Chiari malformation. The interval between these subsequent surgeries was 3 years and 19 months.Chiari malformations are commonly associated with syndromic, complex craniosynostosis and isolated lambdoid craniosynostosis. In appropriately selected patients, a combined posterior cranial vault enlargement and SOD of the foramen magnum is associated with a low complication rate and appears to be an effective procedure.

Although intracerebral schwannomas are typically regarded as benign intracranial tumors, malignancy and recurrence have been reported among patients harboring such neoplasms. The available literature consists of case reports and small series that present variable characteristics distinguishing these unusual lesions. Little advancement has been made to further the understanding and management of these tumors. The authors present 3 cases from their institution that highlight the difference between typical benign intracerebral schwannomas and histopathological variants that may portend more aggressive behavior. Also provided is a review of the literature in the hope of gaining a better understanding of these rare tumors.

Objective. To examine the association between selfreported knee pain and radiographic features of osteoarthritis (OA) of the knee. Methods. A sample of participants in the Baltimore Longitudinal Study of Aging (452 Caucasian males and 223 Caucasian females) completed questionnaires and underwent a standing radiograph of both knees at the same biennial visit between 1984 and 1989. Radiographs were interpreted using both the Kellgren-Lawrence and individual features scales. Odds ratios were calculated for the association of radiographic features with knee pain after adjustment for age, sex, and body mass index. Results. Overall, 156 (23%) persons reported ever having knee pain, and 104 (15%) reported current knee pain (within the previous year). Both ever knee pain and current knee pain were significantly associated with the presence of definite knee OA (Kellgren-Lawrence grade ≥2) and with the presence of all individual features. There was a direct relationship between all measures of severity of radiographic OA and knee pain. Conclusion. These data demonstrate that radiographic features of knee OA are significantly associated with knee pain. The data also support the continued use of the Kellgren-Lawrence grading scale for defining knee OA in population studies.

PURPOSE: To compare spiral computed tomography (CT) with interscan spacing of 4-5 mm versus 8-10 mm for detection rate and level of confidence in diagnosis of pulmonary nodules. MATERIALS AND METHODS: Four radiologists (two junior and two senior faculty members) retrospectively reviewed 67 spiral CT studies with one to six nodules per study. Every second image was masked, which resulted in 8-mm sections every 8 or 10 mm; then all images reconstructed every 4 or 5 mm were reviewed. Lesions were classified as definite, probable, or possible. RESULTS: Narrow interscan spacing yielded more lesions overall (583 vs 566, P < .025) and more definite lesions and fewer equivocal lesions (482 vs 431 and 101 vs 135, respectively; P < .055). The greatest effects were in the reduction of possible lesions (50 vs 88, P < .001) and in the reduction of false-positive diagnoses made by less experienced radiologists. CONCLUSION: Increased reconstruction frequency of spiral CT volume data sets improves detection of pulmonary ...

To compare accuracy of interpretation by radiologists and emergency medicine physicians of conventional radiographs and digitized images on a workstation.One author selected 120 radiographs from the radiology department library, including 62 musculoskeletal, 20 abdominal, and 38 chest examinations. Analog radiographs were digitized. There were 60 positive and 60 control cases. Positive cases demonstrated clinically important disease and had a high degree of diagnostic difficulty. Thirty-one cases were judged to be critical to the patient's immediate care, requiring prompt accurate interpretation. Four groups of readers were used: staff radiologists and emergency medicine physicians and second-year radiology and emergency medicine residents.All reader groups performed better when interpreting conventional radiographs than digitized images. Differences in favor of radiograph reading were statistically significant for overall accuracy related to all cases and to critical cases (P.05, one-tailed test).Results with the teleradiology system were found unacceptable for primary interpretation of the spectrum of radiographs seen in an emergency department.

Spiral computed tomography (CT) has been shown to have significant advantages over dynamic CT by potentially eliminating interscan and intrascan motion, resulting in true volume datasets. The use of spiral CT in the shoulder would potentially be of benefit to those patients in whom CT is needed to define the extent of injury. This report presents our initial experience with spiral CT in acute shoulder trauma.

BACKGROUND We have created a theoretical algorithm for venous thromboembolism prophylaxis after traumatic brain injury (TBI) known as the Parkland Protocol, which stratifies patients into low-, medium-, and high-risk categories for spontaneous progression of hemorrhage. This prospective study characterizes the incidence and timing of radiographic progression of the TBI patterns in these categories. METHODS Inclusion criterion was presentation with intracranial blood between February 2010 and March 2011; exclusion was receipt of only one computed tomographic scan of the head during the inpatient stay or preinjury warfarin. At admission, all patients were preliminarily categorized per the Parkland Protocol as follows: low risk (LR), patients meeting the modified Berne-Norwood criteria; moderate risk (MR), injuries larger than the modified Berne-Norwood criteria without requiring a neurosurgical procedure; high risk (HR), any patient with a craniotomy/monitor. RESULTS A total of 245 patients with intracranial hemorrhage were enrolled during the 13-month study period. Of patients preliminarily classified as LR at admission (n = 136), progression was seen in 25.0%. Spontaneous worsening was seen in 7.4% of LR patients at 24 hours after injury, and no LR patients progressed at 72 hours after injury. In patients initially classified as MR at admission (n = 42), progression was seen in 42.9%, with 91.5% of patients demonstrating stable computed tomographic head scans at 72 hours after injury. In patients initially classified as HR (n = 67), 64.2% demonstrated spontaneous progression of their TBI patterns, with 10.5% continuing to progress at 72 hours after injury. Most repeat scans were performed as routinely scheduled studies (81-91%). CONCLUSION Increases in the incidence of spontaneous worsening were seen as severities of injury progressed from the Parkland Protocol's LR to MR to HR arms. The time frames for these spontaneous worsenings seem to be such that the protocol's theoretical recommendations for venous thromboembolism prophylaxis are worth pursuing as future points of investigation.

Objective. To examine the relationship between serum levels of insulin-like growth factor 1 (IGF-1) and osteoarthritis (OA) of the knee. Methods. Serum IGF-1 levels were compared in 162 male and 101 female subjects age ≥20 stratified by presence of radiographic changes of OA of the knee. Results. Mean serum IGF-1 levels were significantly lower in subjects with knee OA; however, after adjustment for age-related changes in IGF-1 levels, these differences were no longer significant. Conclusion. These data fail to support the hypothesis that serum IGF-1 levels are reduced in subjects with OA of the knee independent of the known age-related changes in these levels.

Radiation therapy is an important modality in the treatment of a wide variety of neoplasms. Skeletal complications of radiation therapy include alterations in bone growth, radiation osteitis with secondary stress fractures, and radiation-induced sarcoma. Routine follow-up of patients who are asymptomatic may show radiation changes that must be differentiated from recurrent disease. In symptomatic patients who are examined for metastatic disease, imaging findings may suggest stress fractures related to prior radiation therapy or, rarely, radiation-induced tumors. Correlation of the clinical presentation, radiation ports, and radiologic findings will often help in the differential diagnosis in these patients.

Amyloidosis is a rare systemic disease caused by extracellular deposition of an insoluble protein. Although it is usually seen in a systemic form, 10%-20% of cases can be localized. Systemic amyloidosis is subclassified into an idiopathic primary form and a secondary or reactive form. Patients with primary amyloidosis have no underlying condition or disease. Men are affected more than women, and the mean age at presentation is 55-60 years. Some causes of secondary amyloidosis are multiple myeloma (10%-15%), rheumatoid arthritis (20%-25%), tuberculosis (50%), or familial Mediterranean fever (26%-40%). Radiographic studies of 90 patients with biopsy-proved primary or secondary amyloidosis were reviewed. Computed tomographic (CT) scans demonstrated a wide spectrum of disease in the cardiothoracic, gastrointestinal, genitourinary, and musculoskeletal systems. Amyloid deposition simulated both inflammatory and neoplastic conditions. Amorphous or irregular calcifications were occasionally identified within the amyloid deposit. Definitive diagnosis requires biopsy confirmation, as CT findings are nonspecific.

The purpose of this study was to evaluate whether radiologists perform equally well with plain radiographs or digitized images displayed on a video monitor in interpretation of difficult orthopedic trauma cases. Interpretations with film and those made from a teleradiology system with spatial resolution of 2.35 line pairs per millimeter were compared in 120 difficult cases, 60 with the selected abnormality (ie, fracture or dislocation) and 60 that were control cases. Seven senior radiology residents and one radiology fellow each interpreted 60 randomly ordered cases with the teleradiology system (1,280 x 1,024-pixel monitors) and 60 cases with the original radiographs. The overall accuracy of the readers was 80.6% for film interpretations and 59.6% for teleradiology screen readings (P.001). Sensitivity was 78.5% for film and 48.8% for on-screen images (P.001), and specificity was 83.2% for film and 72.3% for on-screen images (P.025). Receiver operating characteristic analysis showed rejection of the null hypothesis in favor of film interpretation (P.0049). It was concluded that the teleradiology system was not acceptable for primary diagnostic interpretation of difficult fracture cases.