Exposure region of the Kawase approach and its correlation with skull base anatomy: An evaluation with digital models

The Kawase approach is one of the most used trajectories in skull base surgery. The exposure range of the approach and its correlation with skull base anatomy still demand more exploration. With the help of digital rebuilding, analysis, and measurement, we evaluated the exposure range of the Kawase and extended Kawase approaches and analyzed the correlation between the exposure range and the variants of the petrosal and clival anatomy. The finding of the study demonstrated that compared to the sub-temporal approach, the Kawase approach and the extended Kawase approach significantly added the exposure range in the upper, middle, and partial inferior regions of the clivus. The gains in the exposure volume and area are more when the manipulation angle is less than 135°

Robust and Task-Independent Spatial Profile of the Visual Word Form Activation in Fusiform Cortex

Written language represents a special category of visual information. There is strong evidence for the existence of a cortical region in ventral occipitotemporal cortex for processing the visual form of written words. However, due to inconsistent findings obtained with different tasks, the level of specialization and selectivity of this so called visual word form area (VWFA) remains debated. In this study, we examined category selectivity for Chinese characters, a non-alphabetic script, in native Chinese readers. In contrast to traditional approaches of examining response levels in a restricted predefined region of interest (ROI), a detailed distribution of the BOLD signal across the mid-fusiform cortical surface and the spatial patterns of responses to Chinese characters were obtained. Results show that a region tuned for Chinese characters could be consistently found in the lateral part of the left fusiform gyrus in Chinese readers, and this spatial pattern of selectivity for written words was not influenced by top-down tasks such as phonological or semantic modulations. These results provide strong support for the robust spatial coding of category selective response in the mid-fusiform cortex, and demonstrate the utility of the spatial distribution analysis as a more meaningful approach to examine functional magnetic resonance imaging (fMRI) data

Identification of Larvicidal Constituents of the Essential Oil of Echinops grijsii Roots against the Three Species of Mosquitoes

The screening of Chinese medicinal herbs for insecticidal principles showed that the essential oil of Echinops grijsii Hance roots possessed significant larvicidal activity against mosquitoes. The essential oil was extracted via hydrodistillation and its constituents were determined by gas chromatography‐mass spectrometry (GC‐MS) analysis. GC‐MS analyses revealed the presence of 31 components, with 5‐(3‐buten‐1‐yn‐1‐yl)‐2,2′‐bithiophene (5‐BBT, 27.63%), αterthienyl (α‐T, 14.95%),1,8‐cineole (5.56%) and cis‐β‐ocimene (5.01%) being the four major constituents. Based bioactivity‐directed chromatographic separation of the essential oil led to the isolation of 5‐BBT, 5‐(4‐isovaleroyloxybut‐1‐ynyl)‐2,2′‐bithiophene (5‐IBT) and αT as active compounds. The essential oil of E. grijsii exhibited larvicidal activity against the fourth instar larvae of Aedes albopictus, Anopheles sinensis and Culex pipiens pallens with LC50 values of 2.65 μg/mL, 3.43 μg/mL and 1.47 μg/mL, respectively. The isolated thiophenes, 5‐BBT and 5‐IBT, possessed strong larvicidal activity against the fourth instar larvae of Ae. albopictus(LC50 = 0.34 μg/mL and 0.45 μg/mL, respectively) and An. sinensis(LC50 = 1.36 μg/mL and 5.36 μg/mL, respectively). The two isolated thiophenes also had LC50 values against the fourth instar larvae of C. pipiens pallens of 0.12 μg/mL and 0.33 μg/mL, respectively. The findings indicated that the essential oil of E. grijsii roots and the isolated thiophenes have an excellent potential for use in the control of Ae.albopictus, An. sinensis and C. pipiens pallens larvae and could be used in the search for new, safer and more effective natural compounds as larvicides

Optimizing radiation dose levels in prospectively electrocardiogram-triggered coronary computed tomography angiography using iterative reconstruction techniques: a phantom and patient study.

AIM: To investigate the potential of reducing the radiation dose in prospectively electrocardiogram-triggered coronary computed tomography angiography (CCTA) while maintaining diagnostic image quality using an iterative reconstruction technique (IRT). METHODS AND MATERIALS: Prospectively-gated CCTA were first performed on a phantom using 256-slice multi-detector CT scanner at 120 kVp, with the tube output gradually reduced from 210 mAs (Group A) to 125, 105, 84, and 63 mAs (Group B-E). All scans were reconstructed using filtered back projection (FBP) algorithm and five IRT levels (L2-6), image quality (IQ) assessment was performed. Based on the IQ assessment, Group D(120 kVp, 84 mAs) reconstructed with L5 was found to provide IQ comparable to that of Group A with FBP. In the patient study, 21 patients underwent CCTA using 120 kV, 210 mAs with FBP reconstruction (Group 1) followed by 36 patients scanned with 120 kV, 84 mAs with IRT L5 (Group 2). Subjective and objective IQ and effective radiation dose were compared between two groups. RESULTS: In the phantom scans, there were no significant differences in image noise, contrast-to-noise ratio (CNR) and modulation transfer function (MTF) curves between Group A and the 84 mAs, 63 mAs groups (Groups D and E). Group D (120 kV, 84 mAs and L5) provided an optimum balance, producing equivalent image quality to Group A, at the lowest possible radiation dose. In the patient study, there were no significant difference in image noise, signal-to-noise ratio (SNR) and CNR between Group 1 and Group 2 (p=0.71, 0.31, 0.5, respectively). The effective radiation dose in Group 2 was 1.21 ± 0.14 mSv compared to 3.20 ± 0.58 mSv (Group 1), reflecting dose savings of 62.5% (p<0.05). CONCLUSION: iterative reconstruction technique used in prospectively ECG-triggered 256-slice coronary CTA can provide radiation dose reductions of up to 62.5% with acceptable image quality

Video1_Exposure region of the Kawase approach and its correlation with skull base anatomy: An evaluation with digital models.mp4

The Kawase approach is one of the most used trajectories in skull base surgery. The exposure range of the approach and its correlation with skull base anatomy still demand more exploration. With the help of digital rebuilding, analysis, and measurement, we evaluated the exposure range of the Kawase and extended Kawase approaches and analyzed the correlation between the exposure range and the variants of the petrosal and clival anatomy. The finding of the study demonstrated that compared to the sub-temporal approach, the Kawase approach and the extended Kawase approach significantly added the exposure range in the upper, middle, and partial inferior regions of the clivus. The gains in the exposure volume and area are more when the manipulation angle is less than 135°.</p

Phantom images acquired with routine dose(120 kv, 210 mAs) and different low dose (120 kv, 125–63 mAs) scan.

<p>A: 120 KV, 210 mAs with FBP reconstruction. B: 120 KV, 125 mAs with iDose⁴ reconstruction (L3). C: 120 KV, 105 mAs with iDose⁴ reconstruction (L4). D: 120 KV, 84 mAs with iDose⁴ reconstruction (L5). E: 120 KV, 63 mAs with iDose⁴ reconstruction (L6). The subjective image quality score was equivalent between Group D and Group A. The score of nodule conspicuity in the Group E was significantly lower than that in the Group A.</p

Comparison of general data and objective image quality of patients between Group 1 (routine-dose FBP reconstruction) and Group 2 (120 KV+84 mAs/IRT L5 reconstruction).

<p>Note: ^†indicates the results of <i>x</i>². SNR: Signal-to-noise ratio, CNR: contrast-to-noise ratio.</p

MTF curves of the phantom scans.

<p>No significant differences are observed between Group A and each of the low-dose iterative reconstruction groups (Groups B–E).</p

Subjective image quality scores for phantoms in different dose groups.

<p>FBP: filtered back projection; L: IRT level.</p