Post-traumatic Transient Neurological Dysfunction: A Proposal for Pathophysiology.

Unexplained neurological deterioration is occasionally observed in patients with traumatic brain injuries (TBIs). We aimed to describe the clinical features of post-traumatic transient neurological dysfunction and provide new insight into its pathophysiology. We retrospectively collected data from patients with focal neurological deterioration of unknown origin during hospitalization for acute TBI for 48 consecutive months. Brain imaging, including computed tomography, diffusion-weighted imaging and perfusion-weighted imaging, and electroencephalography were conducted during the episodes. Fourteen (2.0%) patients experienced unexplained focal neurological deterioration among 713 patients who were admitted for traumatic intracranial hemorrhage during the study period. Aphasia was the predominant symptom in all patients, and hemiparesis or hemianopia was accompanied in three patients. These symptoms developed within 14 days after trauma. Structural imaging did not show any significant interval change, and electroencephalography showed persistent arrhythmic slowing in the corresponding hemisphere in most patients. Perfusion imaging revealed increased cerebral blood flow in the symptomatic hemisphere. Surgical intervention and anti-seizure medications were ineffective in abolishing the symptoms. The symptoms disappeared spontaneously after 4 h to 1 month. Transient neurological dysfunction (TND) can occur during the acute phase of TBI. Although TND may last longer than a typical transient ischemic attack or seizure, it eventually resolves regardless of treatment. Based on our observation, we postulate that this is a manifestation of spreading depolarization occurring in the injured brain, which is analogous to migraine aura.

Properties of Cellulose Pulp and Polyurethane Composite Films Fabricated with Curcumin by Using NMMO Ionic Liquid.

Cellulose pulp (CP), polyurethane (PU), and curcumin-based biocompatible composite films were prepared using a simple cost-effective method. Significant structural and microstructural changes were studied using FT-IR spectroscopy, XRD, and SEM. The 5% and 10% gravimetric losses of the CP/PU/curcumin composite were found to be in the range 87.2-182.3 °C and 166.7-249.8 °C, respectively. All the composites exhibited single Tg values in the range 147.4-154.2 °C. The tensile strength of CP was measured to be 93.2 MPa, which dropped to 14.1 MPa for the 1:0.5 CP/PU composite and then steadily increased to 30.5 MPa with further addition of PU. The elongation at the break of the composites decreased from 8.1 to 3.7% with the addition of PU. The addition of PU also improved the water vapor permeability (3.96 × 10-9 to 1.75 × 10-9 g m-1 s-1 Pa-1) and swelling ratio (285 to 202%) of the CP composite films. The CP/PU/curcumin composite exhibited good antioxidant activity and no cytotoxicity when tested on the HaCat cell line. The visual appearance and UV transmittance (86.2-32.9% at 600 nm) of the CP composite films were significantly altered by the incorporation of PU and curcumin. This study demonstrates that CP/PU/curcumin composites can be used for various packaging and biomedical applications.

Usefulness of Self-Expandable Stent for Recanalization of Intracranial Atherosclerotic Disease: Preliminary Experience with Enterprise Stent.

PURPOSE: The purpose of this preliminary study is to evaluate the efficacy and safety of the Enterprise stent for intracranial atherosclerotic disease (ICAD) in patients who presented with acute stroke due to vessel steno-occlusion and in patients with symptomatic disease despite optimum medical management. MATERIALS AND METHODS: A retrospective data analysis was performed on 15 consecutive patients who were treated with Enterprise stenting for recanalization of symptomatic intracranial steno-occlusive arteries due to underlying ICAD. Their clinical and radiological data were reviewed to evaluate procedural results, periprocedural and postprocedural complications, and clinical outcome. RESULTS: Enterprise stents were deployed as a rescue method in 15 patients for recanalization of steno-occlusion. All patients achieved final modified thrombolysis in cerebral infarction (mTICI) score improvement (53.3% with a mTICI score from 0 to 2b or 3, 46.7% with a mTICI score from 1 to 3). Two postprocedural complications (1 symptomatic intracranial hemorrhage and 1 severe brain edema, 13.3%) occurred among 15 patients. Among 12 patients with acute ischemic stroke (AIS), 6 patients (50%) had improvement in their National Institute of Health Stroke Scale of more than 4 at discharge. Seven patients (58.3%) had a good functional outcome with 3-month modified Rankin Score (mRS)≤2, and mortality occurred (mRS=6) in 2 patients (16.7%). None of the 10 AIS and 3 transient ischemic attack patients experienced further ischemic events attributable to the treated steno-occlusion during the follow-up period (ranged from 4 to 36 months, median 12 months). CONCLUSION: This retrospective study suggests that Enterprise stenting can effectively and safely achieve recanalization in symptomatic steno-occlusive intracranial arteries.

Blends of gellan gum/xanthan gum/zinc oxide based nanocomposites for packaging application: Rheological and antimicrobial properties.

Gellan (G) and xanthan gum (X) based nanocomposites containing zinc oxide (Z) nanoparticles (NPs) were fabricated. The effect of zinc oxide on the structure, morphology, and rheological properties of GX composite films were studied. The prepared nanocomposites exhibited shear thinning behavior and a decrease in viscosity when the shear rate was increased. The storage and loss modulus of the GXZ nanocomposites increased with increased zinc oxide percentage and frequency. There was a decrease in complex viscosity at high frequency. The tensile strength (22.1-35.5 MPa), thermal stability (T5%-82.5-96.2 °C), and glass transition temperature (69.9-74.8 °C) of the nanocomposite films increased with the addition of zinc oxide NPs. The results showed that the incorporation of zinc oxide NPs increased the contact angle (54.1-60.8o) and decreased the water vapor permeability (3.83-2.31 × 10-9 g/m2 Pas) of the nanocomposites, indicating a decrease in hydrophilicity. The GXZ nanocomposite films exhibited higher ultra-violet light shielding, and superior thermal and water barrier properties than the GX composite film. Based on these results, GXZ composite films could make a beneficial contribution to food and pharmaceutical packaging applications.

Functional MRI evidence of the cortico-olivary efferent pathway during active auditory target processing in humans.

Auditory target detection has been explored by a number of studies, but none have demonstrated activity in the auditory subcortical centers evoked by the top-down attentional mechanism related to target detection in humans. We applied functional magnetic resonance imaging (fMRI) with sparse sampling to explore activity in the auditory centers, particularly in the subcortex, during an active auditory target detection task. Fourteen healthy subjects with normal hearing tapped the left index finger in response to target tonal stimuli presented among other (non-target) stimuli during continuous white noise stimulation. General linear model, region-of-interest, and connectivity analyses were performed. In the cortex, bilateral auditory cortices as well as the cingulate gyrus, thalamus, and supramarginal gyrus were activated to target stimuli and functionally connected to each other. In the subcortex, the superior olivary complex (SOC) and locus coeruleus were activated to the target but not to the non-target or background noise stimuli. The SOC was the only auditory subcortical center that displayed connectivity to the auditory cortical areas as well as the cingulate and supramarginal gyri during target presentation but not during other conditions. SOC activation appears to be the first fMRI evidence of direct cortico-olivary projections in the human brain as well as SOC participation in auditory target detection. Our results may be an initial step towards developing a noninvasive methodology to evaluate the functional integrity of the auditory efferent system in humans.

Effect of TiO2 on highly elastic, stretchable UV protective nanocomposite films formed by using a combination of k-Carrageenan, xanthan gum and gellan gum.

The hydrogel based composite film was prepared from k-Carrageenan (k-C), xanthan gum (X) and gellan gum (G) by solvent casting method. The transparent films made from these gellable materials with synergistic hydrogel composition have soft texture, good elasticity and excellent break strength. The k-C/X/G based nanocomposite films prepared from different weight ratio of TiO2 nanoparticles were characterized for new packaging materials. The morphology, structure and microstructure properties of the k-C/X/G and TiO2 nanocomposite films were characterized by FT-IR, XRD and SEM analysis. By the incorporation of TiO2 in the k-C/X/G nanocomposite films, the tensile strength, tensile modulus, Tg and thermal stability of the films were greatly enhanced. Due to the hydrophobic nature of the TiO2 nanoparticles there is an increase in contact angle whereas moisture content of the films decreased. The water vapor permeability (WVP) and ultra violet lights transmittance decrease upon increasing the TiO2 content. The k-C/X/G and TiO2 nanocomposites effectively shield the UV light, exhibited partial microbial activity against Staphylococcus aureus and have a high potential for the application in food and non-food industries as UV shielding packaging materials.

BOLD fMRI effects of transcutaneous vagus nerve stimulation in patients with chronic tinnitus.

OBJECTIVE: Vagus nerve stimulation (VNS) is a neuromodulation method used for treatment of epilepsy and depression. Transcutaneous VNS (tVNS) has been gaining popularity as a noninvasive alternative to VNS. Previous tVNS neuroimaging studies revealed brain (de)activation patterns that involved multiple areas implicated in tinnitus generation and perception. In this study, functional magnetic resonance imaging (fMRI) was used to explore the effects of tVNS on brain activity in patients with tinnitus. METHODS: Thirty-six patients with chronic tinnitus received tVNS to the inner tragus, cymba conchae, and earlobe (sham stimulation). RESULTS: The locus coeruleus and nucleus of the solitary tract in the brainstem were activated in response to stimulation of both locations compared with the sham stimulation. The cochlear nuclei were also activated, which was not observed in healthy subjects with normal hearing. Multiple auditory and limbic structures, as well as other brain areas associated with generation and perception of tinnitus, were deactivated by tVNS, particularly the parahippocampal gyrus, which was recently speculated to cause tinnitus in hearing-impaired patients. CONCLUSIONS: tVNS via the inner tragus or cymba conchae suppressed neural activity in the auditory, limbic, and other tinnitus-related non-auditory areas through auditory and vagal ascending pathways in tinnitus patients. The results from this study are discussed in the context of several existing models of tinnitus. They indicate that the mechanism of action of tVNS might be involved in multiple brain areas responsible for the generation of tinnitus, tinnitus-related emotional annoyance, and their mutual reinforcement.

Novel synergistic transparent k-Carrageenan/Xanthan gum/Gellan gum hydrogel film: Mechanical, thermal and water barrier properties.

The aim is to develop novel synergistic transparent k-Carrageenan/Xanthan gum/Gellan gum (k-C/X/G) hydrogel films with different weight ratio composition and to study the effect of these compositions on the physical properties of the films. The structure and morphological properties of the films were investigated by Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray diffraction (XRD) and differential scanning calorimeter (DSC). Results for FT-IR, DSC and SEM analysis showed a clear interaction between k-C, X, and G to form a new material. The mechanical, thermal and water barrier properties such as water vapor permeability (WVP), water contact angle (WCA) and moisture content were determined. The temperature at 5% weight loss (T5%) are in the range of 64.2-121.9 °C. The WVP exhibits are in the range of 1.8-2.4, contact angle are in the range of 32-65.8° and moisture content 16.5-21.51. The hydrogel film had good tensile strength of 19.1-31.0 MPa and elongation at break of 13-19% and tensile modulus of 1.6-2.4 GPa. The UV results indicate that the films were very transparent. The range of properties of the ternary k-C/X/G hydrogel films suggest that the presence molecular interaction and cross linking within the blends.

Feasibility of improved motion-sensitized driven-equilibrium (iMSDE) prepared 3D T1-weighted imaging in the diagnosis of vertebrobasilar artery dissection.

BACKGROUND AND PURPOSE: This study was to evaluate the diagnostic value of improved motion-sensitized driven-equilibrium (iMSDE)-prepared 3D T1-weighted magnetic resonance imaging (MRI) (iMSDE-3DMRI) in intracranial vertebrobasilary dissection (VBD) and to compare iMSDE-3DMRI images with those obtained using 2D high-resolution (HR) MRI with respect to their diagnostic performance in VBD. MATERIALS AND METHODS: We retrospectively reviewed 105 lesions from 102 patients who underwent multimodal imaging and contrast-enhanced iMSDE-3DMRI (CE-iMSDE-3DMRI). The 2D-HRMRI protocol comprised four axial HR images. The CE-iMSDE-3DMRI images were reformatted in the axial, coronal, and sagittal planes. The 2D-HRMRI-based diagnosis was compared with the final diagnosis. The 2D-HRMRI and CE-iMSDE-3DMRI images were examined independently for the diagnosis performance of dissection. RESULTS: VBD was confirmed in 66 lesions in 63 patients; 17 patients had confirmed atherosclerosis, and 22 had no lesions in the vertebrobasilar artery. Diagnostic performances of 2D-HRMRI (AUC, 0.839±0.04; sensitivity, 94.0; specificity, 79.5; diagnostic accuracy, 88.6) CE-iMSDE-3DMRI (AUC, 0.847±0.04; sensitivity, 84.8; specificity, 84.6; diagnostic accuracy, 84.7) and 2D-HRMRI+CE-iMSDE-3DMRI (AUC, 0.893±0.03; sensitivity, 97.0; specificity, 85.0; diagnostic accuracy, 92.5) were good. Comparisons of the diagnostic performance of 2D-HRMRI andCE-iMSDE-3DMRI showed that combined interpretation of 2D-HRMRI and iMSDE-3DMRI yields a significantly higher diagnostic performance than that of 2D-HRMRI (P=0.042). CONCLUSIONS: CE-iMSDE-3DMRI showed good diagnostic performance for the diagnosis of intracranial VBD. These results suggest that CE-iMSDE-3DMRI can be used in combination with 2D-HRMRI for the diagnosis of intracranial VBD.

A Case of Scrub Typhus Related Encephalopathy Presenting as Rapidly Progressive Dementia.

BACKGROUND: An infection known to be a major cause of mild encephalitis/encephalopathy with a reversible splenial lesion (MERS). Rapidly progressive dementia is a neurological condition in which dementia progresses in a short period of time. CASE REPORT: We report on a 78-year-old woman presenting with a rapid decline in cognitive function resulting from a scrub typhus infection. Diffusion weighted images showed a signal intensity at the splenium, and subcortical white matter of both hemispheres suggesting MERS. On the neuropsychological test, the patient showed frontal executive dysfunction. CONCLUSIONS: This case suggests that diagnosticians should consider the possibility that a MERS patient with a rapidly cognitive decline could have a scrub typhus infection because early diagnosis of scrub typhus is very important in this aspect of the treatment.

Development of Synergistic Antimicrobial Coating of p-Aramid Fibers Using Ag Nanoparticles and Glycidyltrimethylammonium Chloride (GTAC) without the Aid of a Cross-Linking Agent.

Functional p-aramid fibers that can express antimicrobial activity were produced by simple processing of silver nanoparticles (AgNPs), which are well known as antimicrobial agents, by using glycidyltrimethylammonium chloride (GTAC), a quaternary ammonium salt. P-aramid fibers were treated with GTAC by the pad-dry-cure process and put into an Ag colloid solution for reactions at 40 °C for 90 min to prepare GTAC/AgNPs-treated p-aramid fibers. Through these processes, GTAC was used as a substitute for existing cross-linking agents. The changes in the degree of attachment of AgNPs to the surface of p-aramid fibers were determined using a scanning electron microscope according to parameters such as GTAC concentration, Ag colloid concentration, and reaction temperature. Through this study, the following results were obtained: (i) The tensile strength of AgNPs/GTAC-treated p-aramid fibers was found to be about 80% of that of untreated p-aramid fibers; (ii) Thermogravimetric analysis showed that the thermal stability of p-aramid fibers did not change much after GTAC/AgNPs treatment and (iii) Antimicrobial activity analysis showed that AgNPs/GTAC-treated p-aramid fibers exhibited superior antibacterial properties compared to untreated p-aramid fibers, which may or may not be the effect of GTAC or AgNPs, or both.

Optimization of Transcutaneous Vagus Nerve Stimulation Using Functional MRI.

OBJECTIVE/HYPOTHESIS: Vagus nerve stimulation (VNS) is an established therapy for drug-resistant epilepsy, depression, and a number of other disorders. Transcutaneous stimulation of the auricular branch of the vagus nerve (tVNS) has been considered as a non-invasive alternative. Several functional magnetic resonance imaging (fMRI) studies on the effects of tVNS used different stimulation parameters and locations in the ear, which makes it difficult to determine the optimal tVNS methodology. The present study used fMRI to determine the most effective location for tVNS. MATERIALS AND METHODS: Four stimulation locations in the ear were compared: the inner tragus, inferoposterior wall of the ear canal, cymba conchae, and earlobe (sham). Thirty-seven healthy subjects underwent two 6-min tVNS stimulation runs per electrode location (monophasic rectangular 500 µs pulses, 25 Hz). General linear model was performed using SPM; region-of-interest analyses were performed for the brainstem areas. RESULTS: Stimulation at the ear canal resulted in the weakest activation of the nucleus of solitary tract (NTS), the recipient of most afferent vagal projections, and of the locus coeruleus (LC), a brainstem nucleus that receives direct input from the NTS. Stimulation of the inner tragus and cymba conchae activated these two nuclei as compared to sham. However, ROI analysis showed that only stimulation of the cymba conchae produced a significantly stronger activation in both the NTS and LC than did the sham stimulation. CONCLUSIONS: These findings suggest that tVNS at the cymba conchae properly activates the vagal pathway and results in its strongest activation, and thus may be the optimal location for tVNS therapies applied to the auricle.

Antibacterial cotton fibers treated with silver nanoparticles and quaternary ammonium salts.

Cotton fibers were treated chemically with glycidyltrimethylammonium chloride (GTAC), a quaternary ammonium salt, and coated with silver nanoparticles/3-mercaptopropyltrimethoxysilane (3-MPTMS) to increase the antibacterial efficacy. The coating process was accomplished by soaking the cotton fibers into a GTAC solution followed by a dry-cure method, and silver colloid/3-MPTMS solution was then applied at 43°C for 90min. The properties of the cotton fibers were analyzed by scanning electron microscopy, X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis. SEM showed a rough surface when the cotton fibers were treated with GTAC/3-MPTMS/silver nanoparticles due to the increasing surface attachment. The existence of silver and 3-MPTMS on the cotton fibers was confirmed by XPS. The cotton fibers treated with both GTAC and silver nanoparticles showed synergistic antibacterial properties against P. aeruginosa.

Effects of scanner acoustic noise on intrinsic brain activity during auditory stimulation.

INTRODUCTION: Although the effects of scanner background noise (SBN) during functional magnetic resonance imaging (fMRI) have been extensively investigated for the brain regions involved in auditory processing, its impact on other types of intrinsic brain activity has largely been neglected. The present study evaluated the influence of SBN on a number of intrinsic connectivity networks (ICNs) during auditory stimulation by comparing the results obtained using sparse temporal acquisition (STA) with those using continuous acquisition (CA). METHODS: Fourteen healthy subjects were presented with classical music pieces in a block paradigm during two sessions of STA and CA. A volume-matched CA dataset (CAm) was generated by subsampling the CA dataset to temporally match it with the STA data. Independent component analysis was performed on the concatenated STA-CAm datasets, and voxel data, time courses, power spectra, and functional connectivity were compared. RESULTS: The ICA revealed 19 ICNs; the auditory, default mode, salience, and frontoparietal networks showed greater activity in the STA. The spectral peaks in 17 networks corresponded to the stimulation cycles in the STA, while only five networks displayed this correspondence in the CA. The dorsal default mode and salience networks exhibited stronger correlations with the stimulus waveform in the STA. CONCLUSIONS: SBN appeared to influence not only the areas of auditory response but also the majority of other ICNs, including attention and sensory networks. Therefore, SBN should be regarded as a serious nuisance factor during fMRI studies investigating intrinsic brain activity under external stimulation or task loads.

Discordance among patient preferences, caregiver preferences, and caregiver predictions of patient preferences regarding disclosure of terminal status and end-of-life choices.

BACKGROUND: The complexity of end-of-life (EOL) communication in cancer care is often increased by family caregivers, who frequently affect the information and decision-making process. We assessed cancer patient preferences (PP), family caregiver preferences (FCP), and family caregiver predictions of patient preferences (FCPPP) regarding the disclosure of terminal status, family involvement in the disclosure process, and EOL choices, and we evaluated the concordances among them. METHODS: A national, multicenter, cross-sectional survey of 990 patient-caregiver dyads (participation rate = 76.2%) was performed. A set of paired questionnaires was independently administered to patients and their caregivers. RESULTS: While patients and family caregivers had wide spectra of preferences, patients significantly preferred disclosure, direct disclosure by a physician, and palliative care options (all P < 0.001). Family caregiver predictions were similar to PP with regard to terminal disclosure (P = 0.35) but significantly different with regard to family involvement in the disclosure process and EOL choices (P < 0.001). The concordances of PP and FCP (κ = 0.08-0.13), and those of PP and FCPPP (κ = 0.09-0.17), were poor. The concordances of FCP and FCPPP were fair to moderate (κ = 0.35-0.67). Discrepancies between PP and FCP and between PP and FCPPP were associated with dysfunctional family communication. CONCLUSIONS: Family caregivers do not generally concur with patients in their preferences, nor do they reliably predict PP. Open dialogue between patient and family caregivers would reduce the discrepancy. More emphasis on incorporating family caregivers in EOL communication is needed from clinical, research, and training perspectives.

The role of US in finding intussusception and alternative diagnosis: a report of 100 pediatric cases.

BACKGROUND: The clinical diagnosis of intussusception remains challenging, because many children with intussusception may present with non-specific signs and symptoms, which overlap with other conditions. Therefore imaging, in particular ultrasonography (US), plays a significant role in the management of these patients. PURPOSE: To evaluate how US can contribute to the diagnosis in clinically suspected intussusception and finding alternative diagnosis. MATERIAL AND METHODS: We retrospectively reviewed reports of US examinations and medical records of 100 patients (51 boys, 49 girls; mean age, 23.0 ± 12.1 months) who underwent abdominal US for clinically suspected intussusception. Each US study was assessed for the presence or absence of intussusception and for a possible alternative diagnosis in cases interpreted as negative for intussusception. RESULTS: Thirty-seven patients had US findings consistent with intussusception, which was confirmed by air enema. In seven patients, US studies were normal. Alternative diagnoses were identified by US for each of the remaining 56 patients, including ileocolitis (n = 20), terminal ileitis (n = 18), mesenteric lymphadenitis (n = 13), choledochal cyst (n = 1), accessory spleen torsion (n = 1), small bowel ileus (n = 1), midgut volvulus with bowel ischemia (n = 1), and hydronephrosis (n = 1). CONCLUSION: With the high sensitivity and specificity of this study we conclude that US is valuable in detecting intussusception and finding the alternative diagnosis.

A comparison of the performance of anatomical MRI and DTI in diagnosing carpal tunnel syndrome.

PURPOSE: To compare the performance of anatomical magnetic resonance imaging (MRI) with that of diffusion tensor imaging (DTI) in the diagnosis of carpal tunnel syndrome (CTS). MATERIALS AND METHODS: We performed 3T anatomical MRI and DTI on 42 patients and 42 age-matched controls. The median nerve cross-sectional area (CSA), relative median nerve signal intensity, and palmar bowing of the flexor retinaculum, assessed with anatomical MRI, and fractional anisotropy (FA) and apparent diffusion coefficient of the median nerve, assessed with DTI, were measured at four locations: the hamate level, the pisiform level (P0), the level located 1cm proximal to the P0 level (P1), and the distal radioulnar joint level (DR). Adding the ratios and differences of the median nerve parameters between the measurements at the DR and other locations to the diagnostic parameters, we evaluated the area under the receiver operating characteristic curves (AUCs) of all the diagnostic parameters of both scans. RESULTS: The AUCs of FA(P1) (0.814) and FA(P0) (0.824) in DTI were larger than the largest AUC for anatomical MRI, CSA(P1) (0.759). However, the receiver operating characteristics of the three parameters were not significantly different (P>0.1). The sensitivity and specificity of CSA(P1) (76.2% and 73.8%) and FA(P1) (73.8% and 76.2%) increased after inclusive and exclusive combination to 90.5% each. CONCLUSION: The individual performances of both scans were not significantly different in diagnosing CTS. Measuring both CSA and FA at P1 may be useful and efficient to utilize the merits of both scans and to increase the CTS diagnostic performance.

The clinical correlation of a new practical MRI method for grading cervical neural foraminal stenosis based on oblique sagittal images.

OBJECTIVE: The purpose of this study was to determine whether each grade in a new system suggested by Park et al. (Park system) to assess cervical neural foraminal stenosis validly correlates with the associated clinical findings and to evaluate the interobserver agreement in grading between two MRI readers. MATERIALS AND METHODS: We evaluated 166 patients (98 men and 68 women; mean age, 46 years) at our institution who underwent oblique sagittal MRI of the cervical spine. Using the new Park grading system, two radiologists evaluated the MRI findings for the presence and grade of cervical neural foraminal stenosis at the most narrow point. A neurosurgeon assessed the associated clinical manifestations. A positive neurologic manifestation of the cervical neural foraminal stenosis was defined as more than one positive neurologic clinical manifestation combined with more than one positive neurologic sign. Interobserver agreements between the two radiologists were analyzed using kappa statistics. Correlation coefficients (R) to assess the relationship between the grade and neurologic manifestations were calculated with nonparametric correlation analysis (Spearman correlation). The relationship between the assigned grade and the clinical manifestations was analyzed several ways: vertebrae level (C4-5, C5-6, or C6-7) and by age group (< 46 years and ≥ 46 years). RESULTS: Among patients who were evaluated by each reader to be grade 0, only 19 (17%) and 20 patients (18%) showed positive neurologic manifestations, respectively, with most patients showing negative neurologic manifestations. Among the patients who were grade 2 and 3, one reader found all patients and the second reader found all but one patient (100% and 93%, respectively) to have positive neurologic manifestations. According to the correlation coefficients, each Park grade was moderately correlated with the associated neurologic manifestations, such that higher grades were associated with more severe clinical manifestations. If we consider grade 2 or 3 MRI findings positive for identifying positive neurologic manifestations, the sensitivities and specificities were 39.7% and 99.0% (reader 1) and 39.7% and 99.0% (reader 2), respectively. CONCLUSION: The Park system, based on oblique sagittal MRI sections, provides a reliable and reproducible assessment of the severity of cervical neural foraminal stenosis. According to the Park system, grades 2 and 3 are associated with positive neurologic manifestations, and the Park system successfully predicts positive neurologic manifestations at these grades.

Comparison between arthroscopic findings and 1.5-T and 3-T MRI of oblique coronal and sagittal planes of the knee for evaluation of selective bundle injury of the anterior cruciate ligament.

OBJECTIVE: The purpose of this study was to evaluate the diagnostic usefulness of combining oblique sagittal and oblique coronal MRI views of the anterior cruciate ligament (ACL) with traditional orthogonal views for the evaluation of selective-bundle ACL injury and to evaluate whether there is a statistical difference in diagnostic ability between 1.5-T and 3-T MRI. MATERIALS AND METHODS: This retrospective study included 114 patients who underwent knee MRI (46 on 1.5 T and 68 on 3 T) and arthroscopy at our institution. Two radiologists evaluated orthogonal views and ACL views on 1.5-T and 3-T MRI in variable combinations. They diagnosed ACL views as normal, entire ligament tear, anteromedial bundle tear, or posterolateral bundle tear. The surgeon then confirmed tears in the anteromedial or posterolateral bundle of the ACL arthroscopically if a selective-bundle tear did exist. The arthroscopically confirmed diagnoses were used as the reference standard. The values were statistically analyzed. RESULTS: Sixty-seven percent of patients showed an ACL tear on arthroscopy, and 33% had a selective bundle tear; of these, 75% were anteromedial bundle tears and 25% were posterolateral bundle tears. On 1.5-T MRI, specificities of each view and combined views were the same (80%). The sensitivities and accuracies of the combined views were higher than the individual views; differences between individual views ranged from 4% to 15%. Reader 1 saw statistically significant differences between the oblique coronal and combined views. Although the performances of reader 2 showed similar results, the p values exceeded the critical value of statistical significance (0.063). On 3-T MRI, differences in specificities between the orthogonal and combined views and between the orthogonal and oblique coronal views were statistically significant (p, 0.016 and 0.008 for readers 1 and 2, respectively). There were no significant differences in the diagnostic performance of 1.5-T and 3-T MRI. CONCLUSION: The oblique coronal view and the combination of the orthogonal view and both additional ACL views provide better diagnostic information with an improvement in specificity on 3-T MRI compared with orthogonal views alone in the diagnosis of selective-bundle tears. Although diagnostic performance was not improved with the addition of the oblique views over orthogonal views on 1.5-T imaging, diagnostic performance was improved on 3-T MRI. Accuracies for individual imaging planes were not significantly different when comparing 1.5-T and 3-T MRI.

Activation of auditory white matter tracts as revealed by functional magnetic resonance imaging.

INTRODUCTION: The ability of functional magnetic resonance imaging (fMRI) to detect activation in brain white matter (WM) is controversial. In particular, studies on the functional activation of WM tracts in the central auditory system are scarce. We utilized fMRI to assess and characterize the entire auditory WM pathway under robust experimental conditions involving the acquisition of a large number of functional volumes, the application of broadband auditory stimuli of high intensity, and the use of sparse temporal sampling to avoid scanner noise effects and increase signal-to-noise ratio. METHODS: Nineteen healthy volunteers were subjected to broadband white noise in a block paradigm; each run had four sound-on/off alternations and was repeated nine times for each subject. Sparse sampling (TR=8 s) was used. RESULTS: In addition to traditional gray matter (GM) auditory center activation, WM activation was detected in the isthmus and midbody of the corpus callosum (CC), tapetum, auditory radiation, lateral lemniscus, and decussation of the superior cerebellar peduncles. At the individual level, 13 of 19 subjects (68 %) had CC activation. Callosal WM exhibited a temporal delay of approximately 8 s in response to the stimulation compared with GM. CONCLUSIONS: These findings suggest that direct evaluation of the entire functional network of the central auditory system may be possible using fMRI, which may aid in understanding the neurophysiological basis of the central auditory system and in developing treatment strategies for various central auditory disorders.