Diversity and determinants of the sigmoid septum and its impact on morphology of the outflow tract as revealed using cardiac computed tomography.

BACKGROUND: The sigmoid septum has been generally evaluated subjectively and qualitatively, without detailed examination of its diversity, impact on the morphology of the left ventricular outflow tract (LVOT), and anatomical background. METHODS: We enrolled 100 patients without any background cardiac diseases (67.5 ± 12.8 years old; 43% women) who underwent cardiac computed tomography. Basal septal morphology was evaluated using antero-superior and medial bulging angles (bidirectional angulation of the basal septum relative to the LVOT). The eccentricity index of the LVOT, area narrowing ratio (LVOT/virtual basal ring area), aortic-to-left ventricular axial angle (angulation of the aortic root relative to the left ventricle), and wedged height (non-coronary aortic sinus to inferior epicardium distance) were also quantified. RESULTS: The antero-superior bulging, medial bulging, aortic-to-left ventricular axial angles, LVOT eccentricity index, area narrowing ratio, and wedged height were 76° ± 17°, 166° ± 27°, 127° ± 9°, 1.8 ± 0.5, 1.0 ± 0.2, and 41.2 ± 9.1 mm, respectively. Both bulging angles were correlated with each other and contributed to the narrowing and deformation of the LVOT. Angulated aortic root was not correlated with either bidirectional septal bulge or LVOT narrowing. Clockwise rotation of the aortic root rotation was an independent predictor of prominent antero-superior septal bulge. Deeper aortic wedging was a common independent predictor of bidirectional septal bulge. CONCLUSIONS: The extent of septal bulge varies in normal hearts. Along with deep aortic wedging, the bidirectional bulge of the basal septum deforms and narrows the LVOT without affecting the virtual basal ring morphology.

Two High-Precision Proximity Capacitance CMOS Image Sensors with Large Format and High Resolution.

This paper presents newly developed two high-precision CMOS proximity capacitance image sensors: Chip A with 12 µm pitch pixels with a large detection area of 1.68 cm2; Chip B with 2.8 µm pitch 1.8 M pixels for a higher resolution. Both fabricated chips achieved a capacitance detection precision of less than 100 zF (10-19 F) at an input voltage of 20 V and less than 10 zF (10-20 F) at 300 V due to the noise cancelling technique. Furthermore, by using multiple input pulse amplitudes, a capacitance detection dynamic range of up to 123 dB was achieved. The spatial resolution improvement was confirmed by the experimentally obtained modulation transfer function for Chip B with various line and space pattens. The examples of capacitance imaging using the fabricated chips were also demonstrated.

Circulating intermediate monocytes and atrial structural remodeling associated with atrial fibrillation recurrence after catheter ablation.

BACKGROUND: Inflammation, such as that associated with intermediate CD14++ CD16+ monocytes and atrial structural remodeling (SRM), may be important in the recurrence of atrial fibrillation (AF) after catheter ablation. However, the relationship between the intermediate CD14++ CD16+ monocytes, SRM, and AF recurrence is unclear. METHODS: Twenty-four patients with AF were enrolled. The proportion of intermediate monocytes (PIM) was assessed before ablation by flow cytometry. As a surrogate marker of SRM, the volume ratio (VR) of signal intensity greater than 1 standard deviation on late-gadolinium enhancement magnetic resonance imaging (LGE-MRI) was calculated. We investigated whether PIM correlated with SRM on LGE-MRI and determined the optimal cutoff value for predicting AF recurrence. RESULTS: Univariate analysis revealed positive correlations between PIM and BNP with SRM (PIM: r = .593, p = .002; BNP: r = .567, p = .004). Multivariable analysis revealed that PIM was independently associated with VR on LGE-MRI (ß = .522; p = .033). The finding of an area under the receiver operating characteristic curve of 0.750 revealed that a VR ≥ 13.3% on LGE-MRI as the optimal cutoff value to predict AF recurrence with 80% sensitivity and 71% specificity, which was associated with PIM ≥ 10.0%. CONCLUSION: Intermediate monocytes were significantly positively correlated with SRM. PIM ≥ 10% was associated with a VR ≥ 13.3% on LGE-MRI, which predicted AF recurrence after catheter ablation.

Feasibility of catheter ablation in patients with persistent atrial fibrillation guided by fragmented late-gadolinium enhancement areas.

BACKGROUND: A computer simulation model has demonstrated that atrial fibrillation (AF) driver can be attached to heterogeneous fibrosis assessed by late gadolinium enhancement magnetic resonance imaging (LGE-MRI). However, it has not been well elucidated in patients with persistent AF. The aim of this study was to investigate whether radiofrequency (RF) applications in the fragmented LGE area (FLA) could terminate AF or convert it to atrial tachycardia (AT) and improve the rhythm outcome. METHODS: A total of 31 consecutive persistent AF patients with FLAs were enrolled (FLA ablation group, mean age: 69 ± 8 years, mean left atrial diameter: 42 ± 6 mm). A favorable response was defined as direct AF termination or AT conversion during RF applications at the FLA. The rhythm outcome was compared between the FLA ablation group and FLA burden-matched pulmonary vein isolation (PVI) group. RESULTS: Favorable responses were found in 15 (48%) of 31 patients in the FLA group (AF termination in seven, AT conversion in eight patients), but not in the PVI group. AF recurrence at 12 months follow-up was significantly less in the FLA ablation group than in the PVI group (4 [13%] vs. 12 [39%] of 31 patients, log-rank p = .023). In patients with a favorable response, AT recurred in 1 (7%) of 15 patients, but AF did not. CONCLUSIONS: FLA ablation could terminate AF or convert it to AT in half of the patients. No AF recurrence was documented in patients with a favorable response.

Late-gadolinium enhancement properties associated with atrial fibrillation rotors in patients with persistent atrial fibrillation.

BACKGROUND: A computational model demonstrated that atrial fibrillation (AF) rotors could be distributed in patchy late-gadolinium enhancement (LGE) areas and play an important role in AF drivers. However, this was not validated in humans. OBJECTIVE: The purpose of this study was to evaluate the LGE properties of AF rotors in patients with persistent AF. METHODS: A total of 287 segments in 15 patients with persistent AF (long-standing persistent AF in 9 patients) that underwent AF ablation were assessed. Non-passively activated areas (NPAs), where rotational activation (AF rotor) was frequently observed, were detected by the novel real-time phase mapping (ExTRa Mapping). The properties of the LGE areas were assessed using the LGE heterogeneity and the density which was evaluated by the entropy (LGE-entropy) and the volume ratio of the enhancement voxel (LGE-volume ratio), respectively. RESULTS: NPAs were found in 61 (21%) of 287 segments and were mostly found around the pulmonary vein antrum. A receiver operating characteristic curve analysis yielded an optimal cutoff value of 5.7% and 10% for the LGE-entropy and LGE-volume ratio, respectively. The incidence of NPAs was significantly higher at segments with an LGE-entropy of >5.7 and LGE-volume ratio of >10% than at the other segments (38 [30%] of 126 vs. 23 [14%] of 161 segments; p = .001). No NPAs were found at segments with an LGE-volume ratio of >50% regardless of the LGE-entropy. Of five patients with AF recurrence, NPAs outside the PV antrum were not ablated in three patients and the remaining NPAs were ablated, but their LGE-entropy and LGE-volume ratio were low. CONCLUSION: AF rotors are mostly distributed in relatively weak and much more heterogenous LGE areas.

Normative Aortic Valvar Measurements in Adults Using Cardiac Computed Tomography　- A Potential Guide to Further Sophisticate Aortic Valve-Sparing Surgery.

BACKGROUND: A thorough understanding of the anatomy of the aortic valve is necessary for aortic valve-sparing surgery. Normal valvar dimensions and their relationships in the living heart, however, have yet to be fully investigated in a 3-dimensional fashion.Methods and Results:In total, 123 consecutive patients (66±12 years, Men 63%) who underwent coronary computed tomographic angiography were enrolled. Mid-diastolic morphology of the aortic roots, including height of the interleaflet triangles, geometric height, free margin length of each leaflet, effective height, and coaptation length were measured using multiplanar reconstruction images. Average height of the interleaflet triangle, geometric height, free margin length, effective height, and the coaptation length were 17.3±1.8, 14.7±1.3, 32.6±3.6, 8.6±1.4, and 3.2±0.8 mm, respectively. The right coronary aortic leaflet displayed the longest free margin length and shortest geometric height. Geometric height, free margin length, and effective height showed positive correlations with aortic root dimensions. Coaptation length, however, remained constant regardless of aortic root dimensions. CONCLUSIONS: Diversities, as well as characteristic relationships among each value involving the aortic root, were identified using living-heart datasets. The aortic leaflets demonstrated compensatory elongation along with aortic root dilatation to maintain constant coaptation length. These measurements will serve as the standard value for revealing the underlying mechanism of aortic regurgitation to plan optimal aortic valve-sparing surgery.

Lesion characteristics between cryoballoon ablation and radiofrequency ablation with a contact force-sensing catheter: Late-gadolinium enhancement magnetic resonance imaging assessment.

BACKGROUND: Pulmonary vein isolation (PVI) lesions after cryoballoon ablation (CBA) are characterized as a wider and more continuous than that after conventional radiofrequency catheter ablation (RFCA) without the contact force (CF)-sensing technology. However, the impact on the lesion characteristics of ablation with a CF-sensing catheter has not been well discussed. We sought to assess the lesions using late-gadolinium enhancement magnetic resonance imaging (LGE-MRI) and to compare the differences between the two groups (CB group vs. RF group). METHODS: A total of 30 consecutive patients who underwent PVI were enrolled (CB group, 18; RF group, 12). The RF applications were delivered with a target lesion size index (LSI) of 5. The PVI lesions were assessed by LGE-MRI 3 months after the PVI. The region around the PV was divided into eight segments: roof, anterior-superior, anterior carina, anterior inferior, bottom, posterior inferior, posterior carina, and posterior superior segment. The lesion width and visual gap of each segment were compared between the two groups. The visual gaps were defined as no-enhancement site of >4 mm. RESULTS: The mean LSI was 4.7 ± 0.7. The lesion width was significantly wider but the visual gaps were more frequently documented at the bottom segment of right PV in the CBA group (lesion width: 8.1 ± 2.2 vs. 6.3 ± 2.2 mm; p = .032; visual gap at the bottom segment or right PV: 39% vs. 0%; p = .016). CONCLUSIONS: The PVI lesion was wider after CBA, while the visual gaps were fewer after RFCA with a CF-sensing catheter.

Bergamottin can be used to assess CYP3A-mediated intestinal first-pass metabolism without affecting P-glycoprotein-mediated efflux in rats.

1. We investigated whether bergamottin would be useful for evaluating CYP3A-mediated intestinal metabolism in rats utilising its characteristics as a mechanism-based inhibitor of CYP3A.2. Buspirone and fexofenadine, probe substrates of CYP3A and P-glycoprotein (P-gp), respectively, were orally co-administered to rats with bergamottin (2.5 mg/kg) or orally administered 2 h after bergamottin pre-treatment. The effect of bergamottin pre-treatment on hepatic CYP3A specifically was investigated with intravenous administration of buspirone. The kobs of bergamottin for CYP3A was calculated based on the portal unbound Cmax.3. Co-administration of bergamottin significantly increased the AUC0-inf for buspirone and fexofenadine by 1.6-fold and 1.7-fold, respectively, indicating that bergamottin inhibited both CYP3A and P-gp.4. Bergamottin pre-treatment significantly elevated the AUC0-inf of oral buspirone by 3.7-fold but exerted no effect on the pharmacokinetics of intravenous buspirone, indicating that bergamottin pre-treatment selectively inhibited CYP3A-mediated intestinal metabolism without affecting the hepatic CYP3A. These findings were supported by the result that the kobs (0.00000118 min-1) of bergamottin for CYP3A was lower than the kdeg (0.0005 min-1) for CYP3A. Furthermore, bergamottin pre-treatment did not affect the pharmacokinetics of oral fexofenadine, suggesting that P-gp was not influenced.5. These profiles of bergamottin enable the convenient assessment of CYP3A-mediated intestinal metabolism.

Usefulness of novobiocin as a selective inhibitor of intestinal breast cancer resistance protein (Bcrp) in rats.

We investigated whether novobiocin is useful for elucidating the contribution of breast cancer resistance protein (Bcrp) to intestinal absorption without affecting the activities of P-glycoprotein (P-gp), cytochrome P450 (CYP) 3 A and hepatic organic anion transporting polypeptide (Oatp) in rats.To determine the effects of novobiocin on Bcrp, P-gp, CYP3A and Oatp activities, we used sulfasalazine, fexofenadine, bosentan and midazolam, respectively, as probe substrates. Each substrate was orally or intravenously administered to rats 15 min after oral novobiocin administration at a dose of 3 mg/kg.Pre-treatment with novobiocin significantly increased the area under the plasma concentration-time curve and the peak plasma concentration of sulfasalazine after oral administration by 3.2- and 5.9-fold, respectively, in rats, whereas its systemic clearance following intravenous dosing was not influenced. These results indicate that novobiocin selectively inhibits intestinal Bcrp-mediated efflux with limited effects on extra-intestinal Bcrp activity.In addition, novobiocin pre-treatment did not significantly alter the pharmacokinetic parameters of orally administered fexofenadine and midazolam or intravenously administered bosentan, suggesting that the effects of novobiocin on other processes were negligible.These findings demonstrate that novobiocin permits estimating the net contribution of Bcrp to intestinal absorption of drug candidates.

Filtered back projection revisited in low-kilovolt computed tomography angiography: sharp filter kernel enhances visualization of the artery of Adamkiewicz.

PURPOSE: The reliability of assessment of the artery of Adamkiewicz before the aortic repair is highly dependent on the display of the continuity of this artery with the aorta, mainly around the vertebral pedicle, by computed tomography angiography (CTA). We hypothesized that the sharp filter kernel can improve visualization of this continuity of the vessel structure because of its edge enhancement and high-spatial resolution. This study was performed to compare the subjective and objective image quality of spinal CTA reconstructed with sharp and smooth filter kernels. METHODS: We retrospectively reviewed 40 consecutive patients who had undergone 80-kV CTA to detect the artery of Adamkiewicz before aortic repair. We measured the CT number and the contrast-to-noise ratio of the anterior spinal artery to the spinal cord. Furthermore, the continuity of the artery of Adamkiewicz was evaluated using a 3-point scale (2 points, absolute; 0 points, undetectable). RESULTS: CTA with the sharp filter kernel showed a significantly higher CT number and contrast-to-noise ratio of the spinal artery than did CTA with the smooth filter kernel (P < .001 for both). Moreover, the sharp filter kernel showed a significantly higher continuity of the artery of Adamkiewicz with the aorta than did the smooth filter kernel (P < .001). CONCLUSIONS: The sharp filter kernel significantly improved the image quality in low-tube-voltage CTA for the assessment of the artery of Adamkiewicz. Thus, CTA with the sharp filter kernel can generate a high-confidence level in the evaluation of the artery of Adamkiewicz.

Age-specific values of Access anti-Müllerian hormone immunoassay carried out on Japanese patients with infertility: a retrospective large-scale study.

BACKGROUND: The ovarian reserve in women is known to correlate with anti-Müllerian hormone (AMH) levels, and currently the latest, third-generation, fully-automated AMH immunoassays, such as Access and Cobas, are beginning to be used for measuring AMH levels. However, the age-specific reference values obtained for AMH levels have been based on samples from an American population, measured using first-generation immunoassays. In this study, we attempted to determine the age-specific AMH reference values based on a large set of samples taken from Japanese infertile women measured by Access so that they could be used by infertility centers treating Japanese and those with similar racial and life-style characteristics. METHODS: The study included 5483 Japanese patients who enrolled in infertility treatment programs at two in-vitro fertilization centers, Shimbashi YUME Clinic and Natural ART Clinic Nihombashi in Tokyo, and who had their serum AMH levels measured between December 2015 and November 2017 by Access. Each patient was represented only once in the study. The mean, median, and standard deviation values were obtained from the measured values for single-year intervals from 28 through 48 years of age (21 age groups in total). The 3D-fitted curve of age-specific mean and median values measured by Access was obtained by regression analysis. RESULTS: The mean and median values decreased with advancing age (mean: R2 = 0.9864; median: R2 = 0.9926). In all age groups, the mean values were higher than the median values; however, the differences between these values decreased with increasing age. CONCLUSIONS: The age-specific AMH reference values measured by Access in this study may serve as a useful diagnostic marker in infertility centers, especially those treating Japanese patients or patients with similar characteristics.

Bat-inspired signal design for target discrimination in human echolocation.

Echolocating bats exhibit sophisticated sonar behaviors using ultrasounds with actively adjusted acoustic characteristics (e.g., frequency and time-frequency structure) depending on the situation. In this study, the utility of ultrasound in human echolocation was examined. By listening to ultrasonic echoes with a shifted pitch to be audible, the participants (i.e., sighted echolocation novices) could discriminate the three-dimensional (3D) roundness of edge contours. This finding suggests that sounds with suitable wavelengths (i.e., ultrasounds) can provide useful information about 3D shapes. In addition, the shape, texture, and material discrimination experiments were conducted using ultrasonic echoes binaurally measured with a 1/7 scaled miniature dummy head. The acoustic and statistical analyses showed that intensity and timbre cues were useful for shape and texture discriminations, respectively. Furthermore, in the discrimination of objects with various features (e.g., acrylic board and artificial grass), the perceptual distances between objects were more dispersed when frequency-modulated sweep signals were used than when a constant-frequency signal was used. These suggest that suitable signal design, i.e., echolocation sounds employed by bats, allowed echolocation novices to discriminate the 3D shape and texture. This top-down approach using human subjects may be able to efficiently help interpret the sensory perception, "seeing by sound," in bat biosonar.

Focal Myocardial Damage in Cardiac Sarcoidosis Characterized by Strain Analysis on Magnetic Resonance Tagged Imaging in Comparison with Fluorodeoxyglucose Positron Emission Tomography Accumulation and Magnetic Resonance Late Gadolinium Enhancement.

OBJECTIVE: The aims of this study were to characterize focal myocardial damage of cardiac sarcoidosis by strain analysis and to compare it with late gadolinium enhancement (LGE) and fluorodeoxyglucose (FDG) positron emission tomography. METHODS: We reviewed 208 segments from 13 cardiac sarcoidosis patients and measured the circumferential strain (Ecc) and the strain change per second (Ecc rate). The mean Ecc and Ecc rate values were compared between the FDG(+) and FDG(-), and the LGE(+) and LGE(-) segments using Welch's t test. RESULTS: The peak and max Ecc rates were better in the LGE(-) segments than in the LGE(+) segments (-11.8 vs -8.9%, 40.5 vs 29.7%/s, both P < 0.001). The max Ecc rate was higher in the FDG(-) segments than in the FDG(+) segments (39.2 vs 31.7%/s, P < 0.001), but the peak Ecc did not differ between the FDG(+) and FDG(-) segments (-11.2 vs -10.1%, P = 0.17). CONCLUSIONS: Strain analysis could reveal focal myocardial damage in the FDG(+) or the LGE(+) segments.

The association between wedging of the aorta and cardiac structural anatomy as revealed using multidetector-row computed tomography.

The aortic root is wedged within the cardiac base. The precise extent of aortic wedging, however, and its influence on the surrounding cardiac structures, has not been systematically investigated. We analysed 100 consecutive patients, who underwent coronary arterial computed tomographic angiography. We assessed the extent of aortic wedging by measuring the vertical distance between the non-adjacent aortic sinus and the inferior epicardium. A shorter distance indicates deeper aortic wedging. We assessed the tilt angle and diameter of the ascending aorta, the relative heights of the left atrial roof and the oval fossa, the shape of the proximal right coronary artery, the angle of the aorta relative to the left ventricular axis, and the lung volume. The mean extent of wedging was 42.7 ± 9.8 mm. Multivariate analysis revealed that ageing, male gender, increased body mass index, patients without cardiomyopathy, the extent of tilting and dilation of the ascending aorta, and lung volume were all independent predictors for deeper aortic wedging (R2  = 0.7400, P < 0.0001). The extent of wedging was additionally correlated with a relatively high left atrial roof (R2  = 0.1394, P < 0.0001) and oval fossa (R2  = 0.1713, P < 0.0001), the shepherd's crook shape of the proximal right coronary artery (R2  = 0.2376, P < 0.0001), and the narrowness of the angulation of the root relative to the left ventricular axis (R2  = 0.2544, P < 0.0001). In conclusion, ageing, male gender, obesity, background cardiac disease, aortic tilting and dilation, and lung volume are all correlated with the extent of wedging of the aortic root within the cardiac base.

Double-Strand Breaks in Genome-Sized DNA Caused by Ultrasound.

DNA double-strand breaks (DSBs) caused by ultrasound were evaluated in a quantitative manner by single-molecule fluorescence microscopy. We compared the effect of time-interval (or pulse) sonication to that of continuous wave (CW) sonication at a fixed frequency of 30 kHz. Pulses caused fewer DSBs than CW sonication under the same total input ultrasound energy when the pulse repetition period was above the order of a second. In contrast, pulses caused more DSBs than CW sonication for pulse widths shorter than a second. These effect of ultrasound on DNA were interpreted in terms of the time-dependent decay in the probability of breakage during the duration of a pulse. We propose a simple phenomenological model by considering a characteristic decay in the probability of DSBs during single-pulse sonication, which reproduces the essence of the experimental trend. In addition, a data analysis revealed a characteristic scaling behavior between the number of pulses and the number of DSBs.

Cytogenetic analysis of the retained products of conception after missed abortion following blastocyst transfer: a retrospective, large-scale, single-centre study.

Cytogenetic analysis of the retained products of conception (POC) is the most effective test for identifying miscarriage causes. However, there has been no large-scale study limited to blastocyst transfer. This study retrospectively reports the findings of 1030 cases in which POC analysis was performed after missed abortion following single blastocyst transfer performed at the Shinbashi Yume Clinic. We identified 19.4% as normal karyotypes and 80.6% as aneuploid. These cases broke down into: 62.3% trisomy; 7.8% double trisomy; 0.5% triple or quadruple trisomy; 1.3% monosomy 21; 3.2% monosomy X; 0.1% 47,XXY; 1.0% polyploidy; 1.0% mixed; 1.1% embryonic mosaicism; and 2.4% structural anomalies. In samples with normal karyotypes, 49.5% were female while 50.5% were male. The occurrence of trisomy and double trisomy were both significantly more frequent in the ≥38 years group than in the ≤37 years group (P < 0.01). Trisomy was significantly more frequently associated with fetal heartbeat (P < 0.01); double trisomy, polyploidy and normal karyotype were significantly more frequent with no fetal heartbeat (P < 0.01). There was no significant difference in the frequency of chromosomal abnormalities between the number of miscarriages or blastocyst quality. Thus, POC cytogenetic testing is highly valuable for ascertaining the cause of miscarriage.

Cardiac apical swinging detected by computed tomography.

In cases with significant pericardial effusion, cardiac apical swinging is a characteristic finding, usually detected by echocardiography and electrocardiography. We present a case showing typical cardiac apical swinging, initially detected by routine computed tomography as a cardiac swinging artifact. The present case highlights the importance of multidisciplinary interpretation of cardiac images, specifically focusing on the difference between static images obtained by computed tomography and dynamic images visualized by echocardiography.

The differences between bisecting and off-center cuts of the aortic root: The three-dimensional anatomy of the aortic root reconstructed from the living heart.

BACKGROUND: It is axiomatic that the diameter of the virtual basal ring of the aortic root, which is elliptical rather than circular, will differ when assessed using between bisecting as opposed to off-center cuts. Such differences, however, which pertain directly to echocardiographic assessments of the so-called valvar annulus, have yet to be systematically explored. METHODS: We retrospectively analyzed 30 patients undergoing coronary computed tomographic angiography, measuring the virtual basal ring diameter using routine multiplanar reconstructions. We made orthogonal bisecting cuts from the nadir of the hinge of the right coronary aortic leaflet to the center of the opposite inter-leaflet fibrous triangle between the noncoronary and left coronary aortic leaflets. We compared these measurements with orthogonal off-center cuts made through the nadirs of the hinges of the adjacent leaflets. RESULTS: The measured diameter of the virtual basal ring was significantly longer when measured using the bisecting cut as opposed to all off-center cuts (mean difference: 1.35±1.34 mm, P<.0001; 0.77±0.95 mm, P=.0001, respectively). The measured diameters of the sinuses of Valsalva, in contrast, were significantly shorter when measured using the bisecting cut (mean difference: -3.24±1.38 mm, P<.0001; -2.86±1.61 mm, P<.0001). CONCLUSIONS: There are significant differences in the diameters of the aortic root, which represent the echocardiographic annulus, when measured using bisecting as opposed to off-center cuts. Account should be taken of these differences when using cross-sectional echocardiographic measurements to assess the dimensions of the aortic root.

[Ictal arterial spin labeling MRI findings in two cases of acute confusional migraine].

Arterial spin labeling (ASL) is a magnetic resonance imaging (MRI) technique that enables visualizing of cerebral blood flow without need of a contrast medium. In recent years, there have been reports from outside Japan related to ASL use in migraine attacks. We report two cases of acute confusional migraine (ACM) in children. At time of confusion, ASL imaging showed reduced blood flow: for the first patient, in both cerebral hemispheres from the occipital lobe through the parietal lobe to the temporal lobe; for the second patient, throughout the left cerebral hemisphere. T1-, T2-, diffusion-weighted images, and fluid attenuation inversion recovery (FLAIR) images indicated normal results. Subsequent ASL re-examinations for both cases showed recovery from reduced blood flow. In our view, ACM can be characterized by a reduction in blood flow not limited to the occipital lobe but across wide regions of the cerebral hemisphere. We consider ASL to be helpful in the difficult differentiation of ACM from other disturbances of consciousness, in addition to enabling repeated examinations without the risks associated with single-photon emission computed tomography (SPECT) concerning radiation exposure or with contrast MRI concerning contrast media use.

Species-specific control of acoustic gaze by echolocating bats, Rhinolophus ferrumequinum nippon and Pipistrellus abramus, during flight.

Based on the characteristics of the ultrasounds they produce, echolocating bats can be categorized into two main types: broadband FM (frequency modulated) and narrowband CF (constant frequency) echolocators. In this study, we recorded the echolocation behavior of a broadband FM (Pipistrellus abramus) and a narrowband CF echolocator species (Rhinolophus ferrumequinum nippon) while they explored an unfamiliar space in a laboratory chamber. During flight, P. abramus smoothly shifted its acoustic gaze in relation to its flight direction, whereas R. ferrumequinum nippon frequently shifted its acoustic gaze from side to side. The distribution of the acoustic gazes of R. ferrumequinum nippon was twice as wide as that of P. abramus. Furthermore, R. ferrumequinum nippon produced double pulses twice as often as P. abramus. Because R. ferrumequinum nippon has a horizontal beam width (-6 dB off-axis angle) half as wide (±20.8 ± 6.0°) as that of P. abramus (±38.3 ± 6.0°), it appears to double the width of its acoustical field of view by shifting its acoustic gaze further off-axis and emitting direction-shifted double pulses. These results suggest that broadband FM and narrowband CF bats actively control their acoustic gazes in a species-specific manner based on the acoustic features of their echolocation signals.