Deep Learning of Time-Signal Intensity Curves from Dynamic Susceptibility Contrast Imaging Enables Tissue Labeling and Prediction of Survival in Glioblastoma.

BACKGROUND AND PURPOSE: An autoencoder can learn representative time-signal intensity patterns to provide tissue heterogeneity measures using dynamic susceptibility contrast MR imaging. The aim of this study was to investigate whether such an autoencoder-based pattern analysis could provide interpretable tissue labeling and prognostic value in isocitrate dehydrogenase (IDH) wild-type glioblastoma. MATERIALS AND METHODS: Preoperative dynamic susceptibility contrast MR images were obtained from 272 patients with IDH wild-type glioblastoma (training and validation, 183 and 89 patients, respectively). The autoencoder was applied to the dynamic susceptibility contrast MR imaging time-signal intensity curves of tumor and peritumoral areas. Representative perfusion patterns were defined by voxelwise K-means clustering using autoencoder latent features. Perfusion patterns were labeled by comparing parameters with anatomic reference tissues for baseline, signal drop, and percentage recovery. In the validation set (n = 89), a survival model was created from representative patterns and clinical predictors using Cox proportional hazard regression analysis, and its performance was calculated using the Harrell C-index. RESULTS: Eighty-nine patients were enrolled. Five representative perfusion patterns were used to characterize tissues as high angiogenic tumor, low angiogenic/cellular tumor, perinecrotic lesion, infiltrated edema, and vasogenic edema. Of these, the low angiogenic/cellular tumor (hazard ratio, 2.18; P = .047) and infiltrated edema patterns (hazard ratio, 1.88; P = .009) in peritumoral areas showed significant prognostic value. The combined perfusion patterns and clinical predictors (C-index, 0.72) improved prognostication when added to clinical predictors (C-index, 0.55). CONCLUSIONS: The autoencoder perfusion pattern analysis enabled tissue characterization of peritumoral areas, providing heterogeneity and dynamic information that may provide useful prognostic information in IDH wild-type glioblastoma.

The recurrence of phantom limb pain with spinal anesthesia.

The recurrence or exacerbation of phantom limb pain (PLP) induced by spinal anesthesia in patients with amputated limbs is rare, but it can occur in any amputee. A 76-year-old woman with an amputated right knee underwent three left knee surgeries with spinal anesthesia over a period of 6 months. She did not experience PLP in the previous two surgeries but experienced the recurrence of severe PLP after the third surgery for the left knee amputation. It is believed that this third operation caused the patient to experience even more severe psychological stress than the previous two operations. Regional blocks can induce PLP in amputees. In addition, PLP can be triggered and exacerbated by psychological factors. Therefore, we suggest that physicians check the patient's psychological state and provide adequate mental stability when performing surgeries with spinal anesthesia in amputated patients.

Thin-Slice Pituitary MRI with Deep Learning-Based Reconstruction for Preoperative Prediction of Cavernous Sinus Invasion by Pituitary Adenoma: A Prospective Study.

BACKGROUND AND PURPOSE: Accurate radiologic prediction of cavernous sinus invasion by pituitary adenoma remains challenging. We aimed to assess whether 1-mm-slice-thickness MRI with deep learning-based reconstruction can better predict cavernous sinus invasion by pituitary adenoma preoperatively and to estimate the depth of invasion and degree of contact in relation to the carotid artery, compared with 3-mm-slice-thickness MRI. MATERIALS AND METHODS: This single-institution, prospective study included 67 consecutive patients (mean age, 53 [SD, 12] years; 28 women), between January and August 2020, who underwent a combined contrast-enhanced T1-weighted imaging protocol of 1-mm-slice-thickness MRI + deep learning-based reconstruction and 3-mm-slice-thickness MRI. An expert neuroradiologist who was blinded to the imaging protocol determined cavernous sinus invasion using the modified Knosp classification on 1-mm-slice-thickness MRI + deep learning-based reconstruction and 3-mm-slice-thickness MRI, respectively. Reference standards were established by the consensus of radiologic, intraoperative, pathologic, and laboratory findings. The primary end point was the diagnostic performance of each imaging protocol, and the secondary end points included depth of invasion and degree of contact in relation to the carotid artery. RESULTS: The diagnostic performance of 1-mm-slice-thickness MRI + deep learning-based reconstruction (area under the curve, 0.79; 95% CI, 0.69 - 0.89) in predicting cavernous sinus invasion by pituitary adenoma was higher than that of 3-mm-slice-thickness MRI (area under the curve, 0.61; 95% CI, 0.52-0.70; P < .001). One-millimeter-slice-thickness MRI + deep learning-based reconstruction demonstrated greater depth of invasion by pituitary adenomas from the medial intercarotid line than 3-mm-slice-thickness MRI (4.07 versus 3.12 mm, P < .001). A higher proportion of cases were in a greater degree of contact with the intracavernous ICA with 1-mm-slice-thickness MRI + deep learning-based reconstruction than with 3-mm-slice-thickness MRI (total encasement, 37.3% versus 13.4%, P < .001; >270°, 38.8% versus 16.4%, P < .001). CONCLUSIONS: Compared with 3-mm-slice-thickness MRI, 1-mm-slice-thickness MRI + deep learning-based reconstruction showed a higher diagnostic performance in preoperatively predicting cavernous sinus invasion by pituitary adenomas and demonstrated a greater depth and degree of contact in relation to the carotid artery.

Hypovascular Cellular Tumor in Primary Central Nervous System Lymphoma is Associated with Treatment Resistance: Tumor Habitat Analysis Using Physiologic MRI.

BACKGROUND AND PURPOSE: The microenvironment of lymphomas is known to be highly variable and closely associated with treatment resistance and survival. We tried to develop a physiologic MR imaging-based spatial habitat analysis to identify regions associated with treatment resistance to facilitate the prediction of tumor response after initial chemotherapy in patients with primary central nervous system lymphoma. MATERIALS AND METHODS: Eighty-one patients with pathologically confirmed primary central nervous system lymphoma were enrolled. Pretreatment physiologic MR imaging was performed, and K-means clustering was used to separate voxels into 3 spatial habitats according to ADC and CBV values. Associations of spatial habitats and clinical and conventional imaging predictors with time to progression were analyzed using Cox proportional hazards modeling. The performance of statistically significant predictors for time to progression was assessed using the concordance probability index. RESULTS: The 3 spatial habitats of hypervascular cellular tumor, hypovascular cellular tumor, and hypovascular hypocellular tumor were identified. A large hypovascular cellular habitat was most significantly associated with short time to progression (hazard ratio, 2.83; P = . 017). The presence of an atypical finding (hazard ratio, 4.41; P = . 016), high performance score (hazard ratio, 5.82; P = . 04), and high serum lactate dehydrogenase level (hazard ratio, 1.01; P = .013) was significantly associated with time to progression. A predictive model constructed using the habitat score and other imaging parameters showed a concordance probability index for prediction of time to progression of 0.70 (95% CI, 0.54-0.87). CONCLUSIONS: A hypovascular cellular tumor habitat is associated with treatment resistance in primary central nervous system lymphoma, and its assessment may refine prechemotherapy imaging-based response prediction for patients with primary central nervous system lymphoma.

Development and Validation of a Deep Learning-Based Model to Distinguish Glioblastoma from Solitary Brain Metastasis Using Conventional MR Images.

BACKGROUND AND PURPOSE: Differentiating glioblastoma from solitary brain metastasis preoperatively using conventional MR images is challenging. Deep learning models have shown promise in performing classification tasks. The diagnostic performance of a deep learning-based model in discriminating glioblastoma from solitary brain metastasis using preoperative conventional MR images was evaluated. MATERIALS AND METHODS: Records of 598 patients with histologically confirmed glioblastoma or solitary brain metastasis at our institution between February 2006 and December 2017 were retrospectively reviewed. Preoperative contrast-enhanced T1WI and T2WI were preprocessed and roughly segmented with rectangular regions of interest. A deep neural network was trained and validated using MR images from 498 patients. The MR images of the remaining 100 were used as an internal test set. An additional 143 patients from another tertiary hospital were used as an external test set. The classifications of ResNet-50 and 2 neuroradiologists were compared for their accuracy, precision, recall, F1 score, and area under the curve. RESULTS: The areas under the curve of ResNet-50 were 0.889 and 0.835 in the internal and external test sets, respectively. The area under the curve of neuroradiologists 1 and 2 were 0.889 and 0.768 in the internal test set and 0.857 and 0.708 in the external test set, respectively. CONCLUSIONS: A deep learning-based model may be a supportive tool for preoperative discrimination between glioblastoma and solitary brain metastasis using conventional MR images.

Vessel Type Determined by Vessel Architectural Imaging Improves Differentiation between Early Tumor Progression and Pseudoprogression in Glioblastoma.

BACKGROUND AND PURPOSE: Currently available perfusion parameters are limited in differentiating early tumor progression and pseudoprogression with no insight about vessel size and type. We aimed to investigate differences in vessel size and type between early tumor progression and pseudoprogression in posttreatment glioblastoma and to demonstrate diagnostic performance using vessel architectural imaging. MATERIALS AND METHODS: Fifty-eight patients with enlarging contrast-enhancing masses in posttreatment glioblastomas underwent simultaneous gradient recalled-echo and spin-echo dynamic susceptibility contrast imaging. Relative CBV and vessel architectural imaging parameters, including the relative vessel size index, peak shift between gradient recalled echo and spin-echo bolus signal peaks, and arterial dominance scores using spatial dominance of arterial/venous vessel type, were calculated and compared between the 2 conditions. The area under the curve and cross-validation were performed to compare the diagnostic performance of the relative CBV, vessel architectural imaging parameters, and their combinations. RESULTS: There were 41 patients with early tumor progression and 17 patients with pseudoprogression. Relative to pseudoprogression, early tumor progression showed a lower peak shift (-0.02 versus 0.33, P = .02) and a lower arterial dominance score (1.46 versus 2.11, P = .001), indicating venous dominance. Patients with early tumor progression had higher relative CBV (1.88 versus 1.38, P = .02) and a tendency toward a larger relative vessel size index (99.67 versus 83.17, P = .15) than those with pseudoprogression. Combining arterial dominance scores and relative CBV showed significantly higher diagnostic performance (area under the curve = 0.82; 95% CI, 0.70-0.94; P = .02) than relative CBV alone (area under the curve = 0.64; 95% CI, 0.49-0.79) in distinguishing early tumor progression from pseudoprogression. CONCLUSIONS: Vessel architectural imaging significantly improved the diagnostic performance of relative CBV by demonstrating venous dominance and a tendency toward larger vessel size in early tumor progression.

Entropy and Turbulence Structure.

Some new perspectives are offered on the spectral and spatial structure of turbulent flows, in the context of conservation principles and entropy. In recent works, we have shown that the turbulence energy spectra are derivable from the maximum entropy principle, with good agreement with experimental data across the entire wavenumber range. Dissipation can also be attributed to the Reynolds number effect in wall-bounded turbulent flows. Within the global energy and dissipation constraints, the gradients (d/dy+ or d2/dy+2) of the Reynolds stress components neatly fold onto respective curves, so that function prescriptions (dissipation structure functions) can serve as a template to expand to other Reynolds numbers. The Reynolds stresses are fairly well prescribed by the current scaling and dynamical formalism so that the origins of the turbulence structure can be understood and quantified from the entropy perspective.

Comparison of Dynamic Contrast-Enhancement Parameters between Gadobutrol and Gadoterate Meglumine in Posttreatment Glioma: A Prospective Intraindividual Study.

BACKGROUND AND PURPOSE: Differences in molecular properties between one-molar and half-molar gadolinium-based contrast agents are thought to affect parameters obtained from dynamic contrast-enhanced imaging. The aim of our study was to investigate differences in dynamic contrast-enhanced parameters between one-molar nonionic gadobutrol and half-molar ionic gadoterate meglumine in patients with posttreatment glioma. MATERIALS AND METHODS: This prospective study enrolled 32 patients who underwent 2 20-minute dynamic contrast-enhanced examinations, one with gadobutrol and one with gadoterate meglumine. The model-free parameter of area under the signal intensity curve from 30 to 1100 seconds and the Tofts model-based pharmacokinetic parameters were calculated and compared intraindividually using paired t tests. Patients were further divided into progression (n = 12) and stable (n = 20) groups, which were compared using Student t tests. RESULTS: Gadobutrol and gadoterate meglumine did not show any significant differences in the area under the signal intensity curve or pharmacokinetic parameters of K trans, Ve, Vp, or Kep (all P > .05). Gadobutrol showed a significantly higher mean wash-in rate (0.83 ± 0.64 versus 0.29 ± 0.63, P = .013) and a significantly lower mean washout rate (0.001 ± 0.0001 versus 0.002 ± 0.002, P = .02) than gadoterate meglumine. Trends toward higher area under the curve, K trans, Ve, Vp, wash-in, and washout rates and lower Kep were observed in the progression group in comparison with the treatment-related-change group, regardless of the contrast agent used. CONCLUSIONS: Model-free and pharmacokinetic parameters did not show any significant differences between the 2 gadolinium-based contrast agents, except for a higher wash-in rate with gadobutrol and a higher washout rate with gadoterate meglumine, supporting the interchangeable use of gadolinium-based contrast agents for dynamic contrast-enhanced imaging in patients with posttreatment glioma.

Differential effect of short-term popular diets on TMAO and other cardio-metabolic risk markers.

BACKGROUND: Dietary nutrient intake and its metabolism by the gut microbiome have recently been implicated in cardiovascular disease (CVD) risk. In particular, trimethylamine N-oxide (TMAO), a metabolite of the gut microbiota, has been shown to be a predictor of incident CVD events. Elevated levels of branched-chain amino acids (BCAA) have also been associated with an increased propensity for insulin resistance. METHODS: To study the association of dietary intake with systemic TMAO, its nutrient precursors, and BCAA levels on fasting plasma levels of TMAO and its nutrient precursors and BCAA, we conducted an exploratory post-hoc analysis of 3 popular diets - high fat (Atkins), Mediterranean (South Beach), and very low fat (Ornish) - using plasma samples from a prior randomized, crossover study, with each isocaloric dietary phase lasting 4 weeks. Metabolites were quantified using stable isotope dilution HPLC with on-line tandem mass spectrometry. RESULTS: Compared to the low fat Ornish phase, the high fat Atkins dietary phase was characterized by increased levels of TMAO (3.3 vs. 1.8 µM, p = 0.01), and the BCAA valine (272.8 vs. 235.8 µM, p = 0.005) and leucine (105.9 vs. 96.4 µM, p = 0.01). The high fat Atkins dietary phase was also associated with higher levels of TMAO (3.3 vs 1.6 µM, p = 0.04), valine (272.8 vs. 240.7 µM, p = 0.004), and leucine (105.9 vs. 96.4 µM, p = 0.01) compared to baseline. CONCLUSIONS: These data suggest that over a 4-week interval, a saturated fat diet that is predominantly animal-based, compared to an isocaloric, low fat, predominantly plant-based diet, is associated with heightened risk for cardiometabolic derangements, as monitored by a higher plasma levels of both TMAO and BCAA.

Determination of Medium Condition Effective to Cryopreservation of Primary Spermatogonial Stem Cells Derived from Porcine Neonatal Testes.

BACKGROUND: The superior genetic resources of breeding pigs have been preserved for use through freezing the sperm or semen. However, because there is no way to collect their sperm or semen after depletion, the generation of sperm via the differentiation of porcine spermatogonial stem cells (SSCs) can be an alternative. To date, there have been no reports of techniques customized to in-vitro culture and differentiation into sperm in porcine SSCs. Accordingly, it is important to preserve porcine SSCs with outstanding genetic backgrounds until these technologies are developed. Unfortunately, a protocol for the long-term preservation of porcine SSCs has yet to be reported. OBJECTIVE: We tried to develop a cryopreservation medium to preserve the characteristics of undifferentiated porcine SSCs for long-term cryopreservation. MATERIALS AND METHODS: SSCs retrieved from porcine testes were freeze-cryopreserved in StemPro-34 medium supplemented with various concentrations of fetal bovine serum (FBS), dimethyl sulfoxide (DMSO), and trehalose; then, after 7 days, the viability and alkaline phosphatase (AP) activity was measured in thawed porcine SSCs. Additionally, we investigated the use of hypotaurine and/or glutathione as antioxidants in the optimized freezing medium for maintaining the viability and AP activity of porcine SSCs during the freezing-cryopreservation-thawing process. RESULTS: Porcine SSCs frozen-cryopreserved-thawed in StemPro-34 medium supplemented with 10% (v/v) FBS, 10% (v/v) DMSO, 200 mM trehalose, 5 mM hypotaurine, and 5 mM glutathione showed the highest viability and AP activity. CONCLUSION: We optimized a cryopreservation medium that inhibits the loss of viability and the increases differentiation post-thawing of the frozen porcine SSCs.

Comparative transcriptome analysis of Ethiopian indigenous chickens from low and high altitudes under heat stress condition reveals differential immune response.

Ethiopia is an ecologically diverse country; the low altitude regions are hot and humid whereas the high altitude regions are cooler. In this study we analyzed the transcriptome response of high altitude (Addis Ababa) and low altitude (Awash) chickens to heat stress conditions that are prevalent in the low altitude regions. The chickens were free ranged for 20 h in an enclosure in Awash, and then the heart, breast muscle and spleen tissues were collected at 6:00 am, 12:00 noon and 6:00 pm to follow a daily circadian cycle. Through RNA-sequencing analysis, we identified differentially expressed genes (DEGs) that were significant (q < 0.05). These DEGs were subjected to protein-protein interaction (PPI) network and gene co-expression network (GCN) analyses to understand their role. KEGG pathway analysis and Gene Ontology analysis of all the identified DEGs and the genes identified from the PPI network and GCN analyses revealed that several immune-related pathways, such as proteasome, focal adhesion, influenza A, the ErbB signaling pathway and glycerophospholipid metabolism, were enriched in response to heat stress. These results suggest that the high altitude chickens were under heat stress and might be immunologically susceptible. Our findings will help in developing a genetic approach to mitigate production loss due to heat stress.

A Compressed-Sensing Based Blind Deconvolution Method for Image Deblurring in Dental Cone-Beam Computed Tomography.

In cone-beam computed tomography (CBCT), reconstructed images are inherently degraded, restricting its image performance, due mainly to imperfections in the imaging process resulting from detector resolution, noise, X-ray tube's focal spot, and reconstruction procedure as well. Thus, the recovery of CBCT images from their degraded version is essential for improving image quality. In this study, we investigated a compressed-sensing (CS)-based blind deconvolution method to solve the blurring problem in CBCT where both the image to be recovered and the blur kernel (or point-spread function) of the imaging system are simultaneously recursively identified. We implemented the proposed algorithm and performed a systematic simulation and experiment to demonstrate the feasibility of using the algorithm for image deblurring in dental CBCT. In the experiment, we used a commercially available dental CBCT system that consisted of an X-ray tube, which was operated at 90 kVp and 5 mA, and a CMOS flat-panel detector with a 200-µm pixel size. The image characteristics were quantitatively investigated in terms of the image intensity, the root-mean-square error, the contrast-to-noise ratio, and the noise power spectrum. The results indicate that our proposed method effectively reduced the image blur in dental CBCT, excluding repetitious measurement of the system's blur kernel.

Clinical Value of Vascular Permeability Estimates Using Dynamic Susceptibility Contrast MRI: Improved Diagnostic Performance in Distinguishing Hypervascular Primary CNS Lymphoma from Glioblastoma.

BACKGROUND AND PURPOSE: A small subset of primary central nervous system lymphomas exhibits high cerebral blood volume, which is indistinguishable from that in glioblastoma on dynamic susceptibility contrast MR imaging. Our study aimed to test whether estimates of combined perfusion and vascular permeability metrics derived from DSC-MR imaging can improve the diagnostic performance in differentiating hypervascular primary central nervous system lymphoma from glioblastoma. MATERIALS AND METHODS: A total of 119 patients (with 30 primary central nervous system lymphomas and 89 glioblastomas) exhibited hypervascular foci using the reference method of leakage-corrected CBV (reference-normalized CBV). An alternative postprocessing method used the tissue residue function to calculate vascular permeability (extraction fraction), leakage-corrected CBV, cerebral blood flow, and mean transit time. Parameters were compared using Mann-Whitney U tests, and the diagnostic performance to distinguish primary central nervous system lymphoma from glioblastoma was calculated using the area under the curve from the receiver operating characteristic curve and was cross-validated with bootstrapping. RESULTS: Hypervascular primary central nervous system lymphoma showed similar leakage-corrected normalized CBV and leakage-corrected CBV compared with glioblastoma (P > .05); however, primary central nervous system lymphoma exhibited a significantly higher extraction fraction (P < .001) and CBF (P = .01) and shorter MTT (P < .001) than glioblastoma. The extraction fraction showed the highest diagnostic performance (the area under the receiver operating characteristic curve [AUC], 0.78; 95% confidence interval, 0.69-0.85) for distinguishing hypervascular primary central nervous system lymphoma from glioblastoma, with a significantly higher performance than both CBV (AUC, 0.53-0.59, largest P = .02) and CBF (AUC, 0.72) and MTT (AUC, 0.71). CONCLUSIONS: Estimation of vascular permeability with DSC-MR imaging further characterizes hypervascular primary central nervous system lymphoma and improves diagnostic performance in glioblastoma differentiation.

Eliminating artifacts in single-grid phase-contrast x-ray imaging for improving image quality.

In this study, we propose a modification to a single-grid phase-contrast x-ray imaging (PCXI) system using a Fourier domain analysis technique to extract absorption, scattering, and differential phase-contrast images. The proposed modification is to rotate the x-ray grid in the image plane to achieve spectral separation between the desired information and the moiré artifact, which is introduced by the superposition of the periodic image of the grid shadow and the periodic sampling by the detector. In addition, we performed some system optimization by adjusting distances between source, object, grid, and detector to further improve image quality. This optimization aimed to increase the spectral spacing between the primary spectrum (lower frequency) and the harmonics of the spectrum (higher frequency) used to extract the various image contrasts. The table-top setup used in the experiment consisted of a focused-linear grid with a 200-lines/inch strip density, a microfocus x-ray tube with a 55-µm focal spot size, and a CMOS flat-panel detector with a 49.5-µm pixel size. The x-ray grid was rotated at 27.8° with respect to the detector and the sample was placed as close as possible to the x-ray tube. Our results indicated that the proposed method effectively eliminated the PCXI artifacts, thus improving image quality.

Identification of the biosynthesis gene cluster for the novel lantibiotic paenilan from Paenibacillus polymyxa E681 and characterization of its product.

AIMS: To analyse the function of a putative lantibiotic gene cluster of Paenibacillus polymyxa E681 and to characterize its product, paenilan. METHODS AND RESULTS: Comparative analysis of the lantibiotic gene cluster of E681 revealed that the cluster, consisting of 11 open reading frames, is involved in the biosynthesis of a class I lantibiotic. The pnlA gene encoding the prepeptide PnlA was identified and P. polymyxa strain EPT14 producing only paenilan was constructed by knockout of the other five antibiotic biosynthetic gene clusters of E681. Paenilan was purified from EPT14 culture by solvent partitioning, ODS silica gel chromatography and reversed-phase preparative HPLC. The molecular mass (2510·10 Da) and structure of paenilan analysed by Nanoelectrospray ionization mass spectrometry (MS) and MS/MS showed that paenilan is a novel class I lantibiotic. Paenilan exhibited antimicrobial activity against Gram-positive bacteria such as Bacillus cereus, Micrococcus luteus and Paenibacillus durus. The paenilan gene is well-conserved in different Paenibacillus sp. isolated from globally distant places. CONCLUSIONS: The lantibiotic gene cluster of P. polymyxa E681 was analysed and its product, a novel and useful lantibiotic named paenilan that inhibits the growth of some Gram-positive bacteria, was characterized. SIGNIFICANCE AND IMPACT OF THE STUDY: Paenibacillus species are a good source of new lantibiotics, and the conservation of the paenilan gene among Paenibacillus sp. implies paenilan has an important function(s) for their survival.

Improved Diagnostic Accuracy Using Arterial Phase CT for Lateral Cervical Lymph Node Metastasis from Papillary Thyroid Cancer.

BACKGROUND AND PURPOSE: Contrast-enhanced CT protocols for papillary thyroid cancer are yet to be optimized. Our aim was to compare the diagnostic accuracy of arterial phase CT and delayed-phase CT protocols for lateral cervical lymph node metastasis from papillary thyroid carcinoma by using the lymph node tissue attenuation. MATERIALS AND METHODS: This retrospective study included 327 lateral cervical lymph nodes (177 metastatic and 150 benign) from 131 patients with papillary thyroid carcinoma (107 initially diagnosed and 24 recurrences). Patients underwent CT by using 1 of 3 protocols: a 70-second (A) or a 35-second (B) delay with 100 mL of iodinated IV contrast or a 25-second delay with 75 mL of IV contrast (C). Two readers independently measured and compared lymph node tissue attenuation between metastatic and benign lymph nodes. An area under the receiver operating characteristic curve analysis was performed to differentiate metastatic and benign lymph nodes after multiple comparison correction for clustered data and was compared across the protocols. RESULTS: The difference in mean lymph node tissue attenuation between metastatic and benign lymph nodes was maximum in protocol C (P < .001 for both readers). Protocol C showed the highest diagnostic performance (area under the receiver operating characteristic curve, 0.88-0.92) compared with protocol A (area under the receiver operating characteristic curve, 0.73-0.74, P < .001 for both readers) and B (area under the receiver operating characteristic curve, .63-0.65, P < .01 for both readers). The sensitivity, specificity, positive predictive value, and negative predictive value of lymph node tissue attenuation by using a 99-HU cutoff value were 83%-87%, 93.7%-97.9%, 95.1%-97.3%, and 81.2%-87%. CONCLUSIONS: A combination of 25-second delay CT and 75 mL of iodinated IV contrast can improve the diagnostic accuracy for lateral lymph node metastasis from papillary thyroid carcinoma compared with a combination of a 35- or 70-second delay with 100-mL of iodinated IV contrast.

Lack of efficacy of levetiracetam in oromandibular and cranial dystonia.

OBJECTIVE: To determine the efficacy of levetiracetam in oromandibular or cranial dystonia. METHODS: We recruited seven subjects with oromandibular or cranial dystonia. Five completed the study, median age was 71 years (range 42-79 years), median disease duration was 12 years (range 2-30 years). Participants were randomized to receive levetiracetam or placebo and were then crossed over. They titrated up to a total daily dose of 4000 mg or the maximum tolerated dose over 3 weeks and maintained that dose for another 3 weeks. The primary endpoint was the percent change of the eyes, mouth, speech, and swallowing Burke-Fahn-Marsden (BFM) subscores from baseline to weeks 6 and 14. Additional endpoints included the BFM subscore at weeks 3 and 11, and the global dystonia severity (GDS) subscore at weeks 3, 6, 11, and 14, as well as all adverse side effects. RESULTS: The mean percent increase in the BFM subscore (placebo: 31.25%, levetiracetam: 12.16%) was not significantly different between the two arms according to the Friedman analysis. The Wilcoxon signed-rank test showed that these percent changes were not significant, indicating that there was no statistical clinical worsening in either arm. The mean percent change of the BFM subscore at weeks 3 and 11 and the mean percent change of the GDS subscore at weeks 3, 6, 11, and 14 were not significantly different between the two arms, and the Wilcoxon signed-rank test did not show statistical significance. CONCLUSION: Levetiracetam does not appear to be efficacious in patients with oromandibular or cranial dystonia.

Comparison of 3 Different Types of Spinal Arteriovenous Shunts below the Conus in Clinical Presentation, Radiologic Findings, and Outcomes.

BACKGROUND AND PURPOSE: Spinal arteriovenous shunts below the conus constitute 3 types of lesions, which have previously been mainly described in case reports, given their rarity, and are sometimes misdiagnosed. The purpose of this study was to describe the features of each type and compare these types as to epidemiologic features, clinical and radiologic presentations, treatment, and outcomes in a consecutive series of 48 cases. MATERIALS AND METHODS: The prospectively collected data bases of 2 referral centers for spinal vascular lesions were retrospectively reviewed. Spinal arteriovenous shunts below the conus were defined as all dural and intradural shunts below the conus medullaris. Clinical features, radiologic findings, treatment results, and clinical outcomes were assessed. RESULTS: There were filum terminale arteriovenous fistulas in 11 patients (22.9%), radicular arteriovenous shunts in 7 patients (14.6%), and spinal dural arteriovenous fistulas in 30 patients (62.5%). Radicular arteriovenous shunts presented at a younger age (P = .017) and with a higher incidence of back pain symptoms (P = .037). A tethered spinal cord was found in 54.5% of patients with filum terminale arteriovenous fistulas and 23.3% of patients with spinal dural arteriovenous fistulas. After treatment, the angiographic complete obliteration rate was 89.4% and spinal function was improved significantly (P < .001). CONCLUSIONS: Three groups of spinal arteriovenous shunts below the conus can be differentiated according to clinical and radiologic features. Filum terminale arteriovenous fistulas are frequently associated with dysraphic malformations, which may suggest a particular embryologic origin.