Chronic nicotinamide mononucleotide supplementation elevates blood nicotinamide adenine dinucleotide levels and alters muscle function in healthy older men.

Preclinical studies have revealed that the elevation of nicotinamide adenine dinucleotide (NAD + ) upon the administration of nicotinamide mononucleotide (NMN), an NAD + precursor, can mitigate aging-related disorders; however, human data on this are limited. We investigated whether the chronic oral supplementation of NMN can elevate blood NAD + levels and alter physiological dysfunctions in healthy older participants. We administered 250 mg NMN per day to aged men for 6 or 12 weeks in a placebo-controlled, randomized, double-blind, parallel-group trial. Chronic NMN supplementation was well tolerated and caused no significant deleterious effect. Metabolomic analysis of whole blood samples demonstrated that oral NMN supplementation significantly increased the NAD + and NAD + metabolite concentrations. There were nominally significant improvements in gait speed and performance in the left grip test, which should be validated in larger studies; however, NMN exerted no significant effect on body composition. Therefore, chronic oral NMN supplementation can be an efficient NAD + booster for preventing aging-related muscle dysfunctions in humans.

Automatic Aortic Valve Cusps Segmentation from CT Images Based on the Cascading Multiple Deep Neural Networks.

Accurate morphological information on aortic valve cusps is critical in treatment planning. Image segmentation is necessary to acquire this information, but manual segmentation is tedious and time consuming. In this paper, we propose a fully automatic aortic valve cusps segmentation method from CT images by combining two deep neural networks, spatial configuration-Net for detecting anatomical landmarks and U-Net for segmentation of aortic valve components. A total of 258 CT volumes of end systolic and end diastolic phases, which include cases with and without severe calcifications, were collected and manually annotated for each aortic valve component. The collected CT volumes were split 6:2:2 for the training, validation and test steps, and our method was evaluated by five-fold cross validation. The segmentation was successful for all CT volumes with 69.26 s as mean processing time. For the segmentation results of the aortic root, the right-coronary cusp, the left-coronary cusp and the non-coronary cusp, mean Dice Coefficient were 0.95, 0.70, 0.69, and 0.67, respectively. There were strong correlations between measurement values automatically calculated based on the annotations and those based on the segmentation results. The results suggest that our method can be used to automatically obtain measurement values for aortic valve morphology.

Forward-projected Model-based Iterative Reconstruction SoluTion in Temporal Bone Computed Tomography: A Comparison Study of All Reconstruction Modes.

OBJECTIVE: Identify appropriate reconstruction modes of Forward-projected model-based Iterative Reconstruction SoluTion (FIRST) in temporal bone computed tomography (CT) and investigate the contribution of spatial resolution and noise to the visual assessment. METHODS: Sixteen temporal bone CT images were reconstructed. Two blinded radiologists assessed 8 anatomical structures and classified the visual assessment. These visual scores were compared across reconstruction modes among each anatomical structure. Visual scores and contrast-to-noise ratio, noise power spectrum (NPS) at low (NPSLow) and high (NPSHigh) spatial frequencies, and 50% modulation transfer function relationships were evaluated. RESULTS: Visual scores differed significantly for the stapedius muscle and osseous spiral lamina, with CARDIAC SHARP, BONE, and LUNG modes for the osseous spiral lamina scoring highest. Visual scores significantly positively correlated with NPSLow, NPSHigh, and 50% modulation transfer function but negatively with contrast-to-noise ratio. CONCLUSIONS: Modes providing higher spatial resolution and lower noise reduction showed an improved visual assessment of CT images reconstructed with FIRST.

A case with familial hypercholesterolemia complicated with severe systemic atherosclerosis intensively treated for more than 30 years.

We present a case of a Japanese patient with familial hypercholesterolemia (FH) caused by a low-density lipoprotein (LDL) receptor gene mutation. A 47-year-old female was referred to our hospital due to her systemic xanthomatosis associated with elevated LDL-cholesterolemia (292 mg/dl). She was diagnosed with heterozygous FH, and started to be treated with simvastatin 10 mg. During her clinical course, she underwent percutaneous coronary intervention (PCI) (at 69 years), coronary artery bypass grafting (CABG) twice (at 62 years, and 75 years), femoral popliteal bypass surgery (at 67 years), together with intensification of lipid-lowering therapies, including proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor. She was admitted to our hospital due to dyspnea on effort, caused by severe aortic valve stenosis as well as sick sinus syndrome at the age of 78 years. transcatheter aortic valve implantation (TAVI) using balloon expandable valve was successfully performed after DDD pacemaker implantation. She was discharged from our hospital without any symptoms. During more than 30 years of treatment period in our institute, we have introduced the latest therapeutic strategies, and treated her intensively. We are proud that we can save life even in this severe case through multiple strategies developed over the decades; however, this case clearly suggests that lipid-lowering therapies should be started much earlier in patients with FH. .

Evaluation of peripheral bronchiole visualization using model-based iterative reconstruction in quarter-detector computed tomography.

This study aimed to evaluate the visualization of peripheral bronchioles in normal lungs via quarter-detector computed tomography (QDCT). Visualization of bronchioles within 10 mm from the pleura is considered a sign of bronchiectasis. However, it is not known peripheral bronchioles how close to the pleura in normal lungs can be tracked using QDCT. This study included 228 parts in 76 lungs from 38 consecutive patients who underwent QDCT. Reconstruction was performed with different thicknesses, increments, and matrix sizes: 0.5-mm thickness and increment with 512 and 1024 matrixes (Group5 and Group10, respectively) and 0.25-mm thickness and increment with 1024 matrix (Group10Thin). The distance between the most peripheral bronchiole visible and the pleura was determined in the three groups. The distance between the peripheral bronchial duct ends and the nearest pleural surface were significantly shorter in the order of Group10Thin, Group10, and Group5, and the mean distances from the pleura in Group10Thin and Group10 were shorter than 10 mm. These findings suggest the visualization of peripheral bronchioles in QDCT was better with a 1024 axial matrix than with a 512 matrix, and with a 0.25-mm slice thickness/increment than with a 0.5-mm slice thickness/increment. Our study also indicates bronchioles within 10 mm of the pleura do not necessarily indicate pathology.

Use of three-dimensional printing of a lumbar skeletal model for intrathecal administration of nusinersen: a brief technical report.

Spinal muscular atrophy (SMA) is an autosomal recessive hereditary neurodegenerative disease causing progressive muscle atrophy, weakness and kyphoscoliosis. Nusinersen is a therapeutic agent for SMA that should be administered intrathecally. However, due to severe kyphoscoliosis, lumbar puncture can be challenging. Here, we present our experience of intrathecal administration of nusinersen in an SMA patient with severe kyphoscoliosis using a life-size three-dimensional printing (3D) skeletal model created with 3D printer. With this strategy, we were able to rapidly and safely perform the lumbar puncture.

Sleep-Induced Glottis Closure in Multiple System Atrophy Evaluated by Four-Dimensional Computed Tomography.

Multiple system atrophy (MSA) is a progressive neurodegenerative disorder. Since patients with MSA often have sleep-related respiratory disorders including upper-airway obstruction and/or central sleep disturbance, appropriate evaluation of the upper airway especially during sleep may be indispensable. Fiberoptic laryngoscopy during diazepam-induced sleep has been reported for upper-airway obstruction verification. However, some patients cannot endure the uncomfortable sensation of the fiberscope. To address these issues, we devised a protocol of four four-dimensional computed tomography (4D-CT) for upper-airway evaluation during sleep. Here, we report the case of patient with MSA who was evaluated for upper-airway obstruction during sleep using 4D-CT. A 46-year-old man (height 1.60 m, weight 79 kg) was admitted to our neurological department for tracheal intubation because of a sudden onset of respiratory failure occurring at night. At the age of 45 years, he was diagnosed as MSA with predominant parkinsonism. As pulmonary disease had been excluded and his swallowing was normal, our differential diagnoses were central sleep apnea or obstructive sleep apnea related to his MSA or obstructive sleep apnea (SA) related to his obesity. A tracheostomy was done to maintain the airway after extubation. Polysomnography showed obstructive SA and not central SA. Awake fiberoptic laryngoscopy showed no upper airway obstruction but bilateral vocal abduction impairment (BVAI) during inspiration. To assess the spatial and temporal conditions of the upper respiratory tract-the patient could not tolerate sleep laryngoscopy-we carried out a 4D-CT. Reconstructed 4D-CT images of respiration during sleep showed clear abnormalities: glottis closure at the terminal stage of inspiration and subsequent velopharyngeal closure. As glottis closure does not occur normally in obesity patients, the cause of the respiratory failure in this patient was considered MSA-related sleep-induced airway obstruction. We decided to keep the tracheostoma, because BVAI in patients with MSA may be getting worse, although central apnea after tracheostomy may cause sudden central origin-related death; 4 months postoperatively, the patient had experienced no further airway-related complications. This report indicates that 4D-CT sequential upper-airway assessment during sleep is useful for determining the abnormalities causing obstructive SA in patients with MSA.

Comparison of image quality between synthetic and patients' electrocardiogram-gated 320-row pediatric cardiac computed tomography.

BACKGROUND: Pediatric cardiac computed tomography (CT) can be acquired without electrode placement by using synthetic electrocardiogram (ECG). OBJECTIVE: To determine whether the depiction of gross cardiac structures and coronary arteries in 320-row pediatric CT is not inferior when CT is gated with synthetic ECG at 150 beats per minute (bpm), compared to the patients' own ECG. MATERIALS AND METHODS: Sixty 320-row CT examinations performed in children younger than 3 years old with congenital cardiac anomaly were enrolled in this retrospective study. Thirty examinations were scanned using the children's own ECG for gating and 30 examinations were scanned using synthetic ECG at 150 bpm. The image quality was compared between the two gating modes using a 3-point scale to delineate the following anatomical structures: atrial septum, ventricular septum, right atrium, right ventricle, left atrium, left ventricle, main pulmonary artery, ascending aorta, aortic arch including the patent ductus arteriosus, descending aorta, right coronary artery and left main trunk. Beam-hardening artifacts from contrast enhancement material were evaluated using a 3-point scale, and the overall image quality was evaluated using a 5-point scale. RESULTS: Synthetic ECG was not inferior to the patients' ECG in depicting each structure, beam-hardening artifact and overall image quality. Average indices were clinically acceptable imaging quality, except for subjective image quality of mid and distal coronary arteries. CONCLUSION: Pediatric cardiac CT in patients younger than 3 years old can be acquired using synthetic ECG gating, with image quality not inferior to the patients' ECG.

Evaluation of the depiction ability of the microanatomy of the temporal bone in quarter-detector CT: Model-based iterative reconstruction vs hybrid iterative reconstruction.

Little is known regarding differences between model-based iterative reconstruction (MBIR) and hybrid iterative reconstruction (HIR) in temporal bone computed tomography (CT). This study compared the ability to depict microstructures in temporal bone in quarter-detector CT (QDCT) between MBIR and HIR.Sixty-two temporal bones in 31 consecutive adult patients who underwent QDCT were included. Reconstruction was performed with Forward projected model-based Iterative Reconstruction SoluTion (FIRST) BONE mild mode and Adaptive Iterative Dose Reduction 3D (AIDR3D) enhanced mild mode. Imaging quality was graded for 3 microstructures (spiral osseous lamina, tympanic membrane, and singular canal).Spiral osseous lamina was significantly well-delineated in the AIDR3D enhanced group, compared with the FIRST group. In nearly all cases with FIRST, spiral osseous lamina was poorly defined. Although there was no significant difference, depiction of the tympanic membrane and singular canal tended to be better with AIDR3D enhanced mode.Routine reconstruction for preoperative temporal bone CT should be performed with HIR, rather than MBIR.

Effect of bolus tracking region-of-interest position within the descending aorta on luminal enhancement of coronary arteries in coronary computed tomography angiography.

To compare coronary artery luminal enhancement in coronary computed tomography angiography (CCTA) between ventral and dorsal region-of-interest (ROI) bolus tracking in the descending aorta.The records of 165 consecutive patients who underwent CCTA with non-helical acquisition from July 2017 to March 2018 were retrospectively examined. We performed 320-row CCTA with bolus tracking [scan triggered at 260 HU in the descending aorta] and 133 patients were finally included. ROI was set in the ventral and dorsal halves of the descending aorta in 68 and 65 patients, respectively.Contrast arrival time was significantly shorter in the dorsal group (ventral: 21.8 ±â€Š0.372 s; dorsal: 20.7 ±â€Š0.369; P = .0295). The mean density of the proximal and distal RCA was significantly higher in the ventral group (proximal: ventral, 428.1 ±â€Š6.95 HU; dorsal, 405.5 ±â€Š7.72 HU, P = .0318; distal: ventral, 418.0 ±â€Š9.29 HU; dorsal, 393.2 ±â€Š9.46 HU, P = .0133).Dorsal bolus tracking ROI in the descending thoracic aorta significantly reduced preparation time and RCA CT values.

Mediastinoscopic view of the bronchial arteries in a series of surgical cases evaluated with three-dimensional computed tomography.

BACKGROUND: We have routinely performed three-dimensional computed tomography (3-D CT) prior to video-assisted transmediastinal esophagectomy to evaluate the small arteries in the mediastinal operative field. This evaluation would be helpful in performing mediastinoscopic esophagectomy. METHODS: Thirty-one patients who underwent transmediastinal esophagectomy with preoperative evaluations by 3-D CT were the study subject. The bronchial arteries depicted by the 3-D CT were classified by their origin and laterality. In 18 of the 31 cases, the surgical video was available and the identification rate in the video was reviewed for each of the categorized bronchial arteries. RESULTS: The detection rates of each classified artery were as follows (abbreviations, detection rate); the intercostal-bronchial trunk (IBT, 22/31), the direct left bronchial artery (LBA, 17/31), the common trunk of bronchial arteries (CTB, 7/31), the direct right bronchial artery (RBA, 2/31), and the ectopic arteries (16/31). The ectopic arteries arose from the aortic arch (11 cases), the right subclavian artery (6 cases) or the left subclavian artery (1 case). The identification rates of IBT, LBA, CTB, RBA and any of the ectopic arteries in the video review were 12/13, 4/8, 3/4, 1/1 and 2/10, respectively. CONCLUSIONS: Preoperative 3-D CT was a highly sensitive evaluation for the bronchial arteries encountered during transmediastinal esophagectomy. Orthotopic arteries except for LBA were frequently identified at the predicted sites. Although RBA and CTB were present infrequently, they often flowed into regional nodes at the bilateral bronchi or the tracheal bifurcation and, therefore, should be preoperatively evaluated.

Pediatric 320-row cardiac computed tomography using electrocardiogram-gated model-based full iterative reconstruction.

BACKGROUND: Full iterative reconstruction algorithm is available, but its diagnostic quality in pediatric cardiac CT is unknown. OBJECTIVE: To compare the imaging quality of two algorithms, full and hybrid iterative reconstruction, in pediatric cardiac CT. MATERIALS AND METHODS: We included 49 children with congenital cardiac anomalies who underwent cardiac CT. We compared quality of images reconstructed using the two algorithms (full and hybrid iterative reconstruction) based on a 3-point scale for the delineation of the following anatomical structures: atrial septum, ventricular septum, right atrium, right ventricle, left atrium, left ventricle, main pulmonary artery, ascending aorta, aortic arch including the patent ductus arteriosus, descending aorta, right coronary artery and left main trunk. We evaluated beam-hardening artifacts from contrast-enhancement material using a 3-point scale, and we evaluated the overall image quality using a 5-point scale. We also compared image noise, signal-to-noise ratio and contrast-to-noise ratio between the algorithms. RESULTS: The overall image quality was significantly higher with full iterative reconstruction than with hybrid iterative reconstruction (3.67±0.79 vs. 3.31±0.89, P=0.0072). The evaluation scores for most of the gross structures were higher with full iterative reconstruction than with hybrid iterative reconstruction. There was no significant difference between full and hybrid iterative reconstruction for the presence of beam-hardening artifacts. Image noise was significantly lower in full iterative reconstruction, while signal-to-noise ratio and contrast-to-noise ratio were significantly higher in full iterative reconstruction. CONCLUSION: The diagnostic quality was superior in images with cardiac CT reconstructed with electrocardiogram-gated full iterative reconstruction.

Subjective and objective evaluation of 10-30% dose reduced coronary artery phantom scans reconstructed with Forward projected model-based Iterative Reconstruction SoluTion (FIRST).

The data presented in this articles are related to the research article entitled "The feasibility of Forward-projected model-based Iterative Reconstruction SoluTion (FIRST) for coronary 320-row computed tomography angiography: a pilot study" (E. Maeda, N. Tomizawa, S. Kanno, K. Yasaka, T. Kubo, K. Ino, R. Torigoe, K. Ohtomo, 2016) [1]. This article describes subjective and objective evaluations of 2 mm-4 mm coronary artery phantom scanned with 100% dose and reconstructed with hybrid iterative reconstruction, and 90%, 80% and 70% dose reconstructed with full iterative reconstruction.

The feasibility of Forward-projected model-based Iterative Reconstruction SoluTion (FIRST) for coronary 320-row computed tomography angiography: A pilot study.

BACKGROUND: We aimed to assess and compare the influence of Forward projected model-based Iterative Reconstruction SoluTion (FIRST), a recently introduced full iterative reconstruction method, on radiation doses and image quality with that of Adaptive Iterative Dose Reduction (AIDR) 3D for 320-row cardiac computed tomography (CT). METHODS: A total of 184 patients subjected to single-beat reconstruction cardiac CT were retrospectively included. The first 89 patients received standard radiation doses; their data were reconstructed using AIDR 3D, whereas the last 95 patients received in average 20% reduction in tube current; their data were reconstructed using FIRST. Subjective image quality (blooming, image sharpness, image noise, and overall subjective image quality) were graded using 3-, 5-, 4-, and 4-point scales (0-2, 1-5, 1-4, and 1-4), respectively; for all items, the highest score indicated excellent image quality. Image noise and signal-to-noise ratios at proximal segments were analyzed as objective measures of image quality. RESULTS: FIRST reconstruction allowed 28% dose reduction compared with AIDR 3D (1.88 vs. 2.61 mSv, p = 0.012) and yielded better subjective image quality in terms of blooming, image sharpness, image noise, and overall image quality (1.10 vs. 1.01, p = 0.0007; 3.02 vs. 2.74, p < 0.0001; 3.61 vs. 3.17, p < 0.0001; and 3.30 vs. 2.98, p < 0.0001, respectively). Although no significant difference was observed in image noise, the signal-to-noise ratio was significantly higher with FIRST (18.4 vs. 16.6, p = 0.0066). CONCLUSIONS: FIRST allowed 28% dose reduction while improving image quality.

Feasibility of Diffusion Tensor Imaging at 1.5T Using Multi-Band Echo Planar Acquisition.

We report that diffusion tensor imaging (DTI) and tractography (DTT) of the pyramidal tracts using multi-band (MB) EPI could be a useful tool with a 1.5T MRI. We compared images using single-band EPI (SB-EPI) and MB-EPI. MB-EPI could reduce the scanning time by about 40%. We demonstrated that it is comparable between image qualities of SB-EPI and MB-EPI using tract-specific analysis and dice coefficients. Therefore, MB-EPI can promote high-speed DTI and DTT in clinical applications.

Diagnostic Phase of Calcium Scoring Scan Applied as the Center of Acquisition Window of Coronary Computed Tomography Angiography Improves Image Quality in Minimal Acquisition Window Scan (Target CTA Mode) Using the Second Generation 320-Row CT.

OBJECTIVE: To compare the image quality of coronary computed tomography angiography (CCTA) acquired under two conditions: 75% fixed as the acquisition window center (Group 75%) and the diagnostic phase for calcium scoring scan as the center (CS; Group CS). METHODS: 320-row cardiac CT with a minimal acquisition window (scanned using "Target CTA" mode) was performed on 81 patients. In Group 75% (n = 40), CS was obtained and reconstructed at 75% and the center of the CCTA acquisition window was set at 75%. In Group CS (n = 41), CS was obtained at 75% and the diagnostic phase showing minimal artifacts was applied as the center of the CCTA acquisition window. Image quality was evaluated using a four-point scale (4-excellent) and the mean scores were compared between groups. RESULTS: The CCTA scan diagnostic phase occurred significantly earlier in CS (75.7 ± 3.2% vs. 73.6 ± 4.5% for Groups 75% and CS, resp., p = 0.013). The mean Group CS image quality score (3.58 ± 0.63) was also higher than that for Group 75% (3.19 ± 0.66, p < 0.0001). CONCLUSIONS: The image quality of CCTA in Target CTA mode was significantly better when the center of acquisition window is adjusted using CS.

Optimized heart rate for 320-row cardiac CT can be feasibly predicted from prescan parameters.

To evaluate the degree of heart rate (HR) changes at rest (HRrest), during breath hold (HRtest), and during cardiac CT examinations (HRscan) in a large group of patients , and to derive and asses the feasibility of a predictive formula for HRscan. HRrest, HRtest, and HRscan were retrospectively compared in a total of 563 consecutive patients who underwent 320-row cardiac CT. Multiple regression analysis was performed to derive predictive formulae for HRscan in the entire study population and, in each group of patients with decreased (Dec) or increased (Inc) HR during breath hold. The predictive formula was evaluated as accurate when less than 5 % of the actual HRscan exceeded the predicted HRscan by ±5 beats per minute (bpm). The average values of the HRtest (65.3 ± 12.0 bpm) and HRscan (63.7 ± 11.9 bpm) significantly decreased from those of the HRrest (68.4 ± 11.9 bpm) (p < 0.0001). The predictive formula (HRscan = 3.601 + 0.113HRrest + 0.8HRtest) was determined to be accurate only in Group Dec. The HRtest significantly decreased from the HRrest, and the HRscan significantly decreased from the HRtest. An accurate predictive formula for HRscan could be built only for Group Dec.

Combined use of diffusion tensor tractography and multifused contrast-enhanced FIESTA for predicting facial and cochlear nerve positions in relation to vestibular schwannoma.

OBJECT: The authors assessed whether the combined use of diffusion tensor tractography (DTT) and contrast-enhanced (CE) fast imaging employing steady-state acquisition (FIESTA) could improve the accuracy of predicting the courses of the facial and cochlear nerves before surgery. METHODS: The population was composed of 22 patients with vestibular schwannoma in whom both the facial and cochlear nerves could be identified during surgery. According to DTT, depicted fibers running from the internal auditory canal to the brainstem were judged to represent the facial or vestibulocochlear nerve. With regard to imaging, the authors investigated multifused CE-FIESTA scans, in which all 3D vessel models were shown simultaneously, from various angles. The low-intensity areas running along the tumor from brainstem to the internal auditory canal were judged to represent the facial or vestibulocochlear nerve. RESULTS: For all 22 patients, the rate of fibers depicted by DTT coinciding with the facial nerve was 13.6% (3/22), and that of fibers depicted by DTT coinciding with the cochlear nerve was 63.6% (14/22). The rate of candidates for nerves predicted by multifused CE-FIESTA coinciding with the facial nerve was 59.1% (13/22), and that of candidates for nerves predicted by multifused CE-FIESTA coinciding with the cochlear nerve was 4.5% (1/22). The rate of candidates for nerves predicted by combined DTT and multifused CE-FIESTA coinciding with the facial nerve was 63.6% (14/22), and that of candidates for nerves predicted by combined DTT and multifused CE-FIESTA coinciding with the cochlear nerve was 63.6% (14/22). The rate of candidates predicted by DTT coinciding with both facial and cochlear nerves was 0.0% (0/22), that of candidates predicted by multifused CE-FIESTA coinciding with both facial and cochlear nerves was 4.5% (1/22), and that of candidates predicted by combined DTT and multifused CE-FIESTA coinciding with both the facial and cochlear nerves was 45.5% (10/22). CONCLUSIONS: By using a combination of DTT and multifused CE-FIESTA, the authors were able to increase the number of vestibular schwannoma patients for whom predicted results corresponded with the courses of both the facial and cochlear nerves, a result that has been considered difficult to achieve by use of a single modality only. Although the 3D image including these prediction results helped with comprehension of the 3D operative anatomy, the reliability of prediction remains to be established.

Feasibility of diffusion tensor tractography for preoperative prediction of the location of the facial and vestibulocochlear nerves in relation to vestibular schwannoma.

BACKGROUND: According to recent findings, diffusion tensor tractography (DTT) only allows prediction of facial nerve location in relation to vestibular schwannoma (VS) with high probability. However, previous studies have not mentioned why only the facial nerve was selectively visualized. Our previous report investigated the optimal conditions of DTT for normal facial and vestibulocochlear nerves. In the present study, we applied the optimal conditions of DTT to VS patients to assess the feasibility of DTT for the facial and vestibulocochlear nerves. METHODS: We investigated 11 patients with VS who underwent tumor resection. Visualized tracts were compared with locations of the facial and cochlear nerves as identified by intraoperative electrophysiological monitoring. RESULTS: With the proposed method, visualized tracts corresponded to pathway area of the facial or cochlear nerves in nine of 11 patients (81.8%); specifically, to the pathway area of the facial nerve in three of 11 patients (27.3%), and to the pathway area of the cochlear nerve in six of 11 patients (54.5%). CONCLUSIONS: We visualized facial or vestibulocochlear nerves in nine of 11 patients (81.8%). For the first time, DTT proved able to visualize not only the facial nerve but also the vestibulocochlear nerve in VS patients. Despite our findings, good methods for distinguishing whether a visualized nerve tract represents facial nerve, vestibulocochlear nerve, or only noise remain unavailable. Close attention should therefore be paid to the interpretation of visualized fibers.

Longitudinal gray-matter volume change in the default-mode network: utility of volume standardized with global gray-matter volume for Alzheimer's disease: a preliminary study.

Our aim was to show whether sensitivity for detecting volume changes in regional gray matter in default mode network (DMN) at converted [from mild cognitive impairment to Alzheimer's disease (from MCI to AD)] phase was improved by use of a standardized volume with global gray-matter volume. T1-weighted MR images (T1WI) of seven normal subjects and seven converted (from MCI to AD) patients were obtained from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database. Gray-matter images segmented with Statistical Parametric Mapping 5 were measured by the atlas-based method. We focused on five nodes of the DMN. For each phase, region of interest (ROI) volumes in the five nodes were standardized by two methods: (1) the ratio to the screening phase (S_volume) and (2) the ratio to the screening phase after both volumes were standardized by the global gray-matter volume (S_N_volume). Significant group differences between longitudinal gray-matter volume change of the converted (from MCI to AD) group and that of the normal group were found in lateral temporal cortex by S_N_volume, and precuneus by S_N_volume. These findings are useful for improving the understanding of DMN volume changes at the converted (from MCI to AD) phase.