Enhanced structural connectivity within the motor loop in professional boxers prior to a match.

Professional boxers train to reduce their body mass before a match to refine their body movements. To test the hypothesis that the well-defined movements of boxers are represented within the motor loop (cortico-striatal circuit), we first elucidated the brain structure and functional connectivity specific to boxers and then investigated plasticity in relation to boxing matches. We recruited 21 male boxers 1 month before a match (Time1) and compared them to 22 age-, sex-, and body mass index (BMI)-matched controls. Boxers were longitudinally followed up within 1 week prior to the match (Time2) and 1 month after the match (Time3). The BMIs of boxers significantly decreased at Time2 compared with those at Time1 and Time3. Compared to controls, boxers presented significantly higher gray matter volume in the left putamen, a critical region representing motor skill training. Boxers presented significantly higher functional connectivity than controls between the left primary motor cortex (M1) and left putamen, which is an essential region for establishing well-defined movements. Boxers also showed significantly higher structural connectivity in the same region within the motor loop from Time1 to Time2 than during other periods, which may represent the refined movements of their body induced by training for the match.

Mixed Reality Visualization of Radiation Dose for Health Professionals and Patients in Interventional Radiology.

For interventional radiology, dose management has persisted as a crucially important issue to reduce radiation exposure to patients and medical staff. This study designed a real-time dose visualization system for interventional radiology designed with mixed reality technology and Monte Carlo simulation. An earlier report described a Monte-Carlo-based estimation system, which simulates a patient's skin dose and air dose distributions, adopted for our system. We also developed a system of acquiring fluoroscopic conditions to input them into the Monte Carlo system. Then we combined the Monte Carlo system with a wearable device for three-dimensional holographic visualization. The estimated doses were transferred sequentially to the device. The patient's dose distribution was then projected on the patient body. The visualization system also has a mechanism to detect one's position in a room to estimate the user's exposure dose to detect and display the exposure level. Qualitative tests were conducted to evaluate the workload and usability of our mixed reality system. An end-to-end system test was performed using a human phantom. The acquisition system accurately recognized conditions that were necessary for real-time dose estimation. The dose hologram represents the patient dose. The user dose was changed correctly, depending on conditions and positions. The perceived overall workload score (33.50) was lower than the scores reported in the literature for medical tasks (50.60) for computer activities (54.00). Mixed reality dose visualization is expected to improve exposure dose management for patients and health professionals by exhibiting the invisible radiation exposure in real space.

Magnetic resonance imaging changes in Asian people living with HIV.

BACKGROUND: Previous studies have reported a significant increase in age-related magnetic resonance imaging (MRI) changes in relatively younger people living with HIV (PLWH). However, there is little data available for brain changes in Asian PLWH. The data to differentiate HIV specific brain change from usual aging change was also sparse. To clarify them, we assessed the presence of leukoaraiosis and brain atrophic changes on MRI in young and middle-aged Japanese PLWH. METHODS: We reviewed data from well-controlled PLWH (age: 20-64 years) and coeval controls. We evaluated the presence of leukoaraiosis, as well as the extent of whole-brain grey matter (GM) atrophy and parahippocampal atrophy on brain MRI and determined between-group differences. Moreover, we evaluated the severity of parahippocampal atrophy based on the voxel-based specific regional analysis system for Alzheimer's disease. RESULTS: We enrolled 40 PLWH and 33 controls (median age: 40.15 and 48.00 years, respectively, [p = .3585]). Leukoaraiosis was significantly more prevalent among the PLWH (20 cases [50%]) than in the controls (9 cases [27.3%]) (univariate: p = .0483, multivariate: p = .0206). The extent of whole-brain GM atrophy was significantly greater in the PLWH than in the controls (univariate: p < .001, multivariate: p = .0012). Contrastingly, there was no significant between-group difference in the extent and severity of parahippocampal atrophy. CONCLUSIONS: Aging changes in the brain were significantly more prevalent in well-controlled Japanese PLWH. However, the process of atrophic brain changes might differ between HIV and one of age-related diseases, Alzheimer's disease.

First experience of 192Ir source stuck event during high-dose-rate brachytherapy in Japan.

PURPOSE: To share the experience of an iridium-192 (192Ir) source stuck event during high-dose-rate (HDR) brachytherapy for cervical cancer. MATERIAL AND METHODS: In 2014, we experienced the first source stuck event in Japan when treating cervical cancer with HDR brachytherapy. The cause of the event was a loose screw in the treatment device that interfered with the gear reeling the source. This event had minimal clinical effects on the patient and staff; however, after the event, we created a normal treatment process and an emergency process. In the emergency processes, each staff member is given an appropriate role. The dose rate distribution calculated by the new Monte Carlo simulation system was used as a reference to create the process. RESULTS: According to the calculated dose rate distribution, the dose rates inside the maze, near the treatment room door, and near the console room were ≅ 10-2 [cGy · h-1], 10-3 [cGy · h-1], and << 10-3 [cGy · h-1], respectively. Based on these findings, in the emergency process, the recorder was evacuated to the console room, and the rescuer waited inside the maze until the radiation source was recovered. This emergency response manual is currently a critical workflow once a year with vendors. CONCLUSIONS: We reported our experience of the source stuck event. Details of the event and proposed emergency process will be helpful in managing a patient safety program for other HDR brachytherapy users.

Imaging spectrum of abnormal subcutaneous and visceral fat distribution.

Adipose tissue plays multiple and complex roles not only in mechanical cushioning and energy storage but also as an important secretory organ that regulates energy balance and homeostasis multilaterally. Fat tissue is categorized into subcutaneous fat tissue (SCAT) or visceral fat tissue (VSA) depending on its distribution, with the two having different metabolic functions. Near-total lack of fat in congenital/acquired generalized lipodystrophy, cachexia, or any other severe malnutrition condition induces severe multi-organ dysfunction due to lack of production of leptin and other adipokines. Increased visceral fat tissue secondary to obesity, hypercortisolism, or multiple symmetric lipomatosis raises the risk of insulin resistance, cardiac complications, and airway or spinal canal stenosis, although the fat distribution pattern differs in each condition. Partial abnormal fat distribution conditions such as HIV/HAART therapy-associated lipodystrophy, familial partial lipodystrophies, and acquired partial lipodystrophy frequently show a mixture of lipoatrophy and lipohypertrophy with metabolic dysfunction. Characteristic imaging features in conditions with local abnormal fat distribution can provide information about a patient's co-existent/unrecognized disease(s), past medical history, or lifestyle. Knowledge of characteristic abnormal fat distribution patterns can contribute to proper and timely therapeutic decision-making and patient education.

Immersive Radiation Experience for Interventional Radiology with Virtual Reality Radiation Dose Visualization Using Fast Monte Carlo Dose Estimation.

For interventional radiology (IR), understanding the precise dose distribution is crucial to reduce the risks of radiation dermatitis to patients and staff. Visualization of dose distribution is expected to support radiation safety efforts immensely. This report presents techniques for perceiving the dose distribution using virtual reality (VR) technology and for estimating the air dose distribution accurately using Monte Carlo simulation for VR dose visualization. We adopted an earlier reported Monte-Carlo-based estimation system for IR and simulated the dose in a geometrical area resembling an IR room with fluoroscopic conditions. Users of our VR system experienced a simulated air dose distribution in the IR room while the irradiation angle, irradiation timing, and lead shielding were controlled. The estimated air dose was evaluated through comparison with measurements taken using a radiophotoluminescence glass dosimeter. Our dose estimation results were consistent with dosimeter readings, showing a 13.5% average mutual difference. The estimated air dose was visualized in VR: users could view a virtual IR room and walk around in it. Using our VR system, users experienced dose distribution changes dynamically with C-arm rotation. Qualitative tests were conducted to evaluate the workload and usability of our VR system. The perceived overall workload score (18.00) was lower than the scores reported in the literature for medical tasks (50.60) and computer activities (54.00). This VR visualization is expected to open new horizons for understanding dose distributions intuitively, thereby aiding the avoidance of radiation injury.

Cerebral blood flow in young and middle-aged people living with HIV.

Purpose: Neurocognitive disorder has been noted as a long-term complication in individuals with HIV. In people living with HIV, regardless of treatment, age-related changes like arteriosclerosis are well-known to be accelerated. Such accelerated aging changes may decrease cerebral blood flow in younger generations with HIV, increasing the rate of occurrence of neurocognitive disorders. We investigated regional cerebral blood flows in well-controlled Japanese people living with HIV under 65 years old to clarify whether age-related changes in regional cerebral blood flows are accelerated in people living with HIV.Method: Japanese male HIV patients >20 years old but <65 years old who visited Teikyo University Hospital between August 2013 and September 2015 were recruited to and enrolled in this study. Healthy coeval male volunteers during the same period were recruited as controls. Magnetic resonance imaging was performed. Twelve regional cerebral blood flows were calculated from pseudocontinuous arterial spine labelling data.Results: Participants in this study comprised 40 individuals with HIV (HIV-positive group) and 33 non-HIV individuals (Control group). Median age was 40.15 years [interquartile range (IQR), 32.80-50.55 years] for the HIV-positive group and 48.00 years [IQR, 37.75-59.25 years; p = 0.3585] for the Control group. No significant differences in regional cerebral blood flows were seen between groups. In the HIV-positive group, cerebral blood flows decreased with age in the neocortex, although no significant decrease was observed in any of the regions in the control group.Conclusions: Significant age-related declines in cerebral blood flows in the neocortex may occur earlier in HIV patients.

Hepatic tumor classification using texture and topology analysis of non-contrast-enhanced three-dimensional T1-weighted MR images with a radiomics approach.

The purpose of this study is to evaluate the accuracy for classification of hepatic tumors by characterization of T1-weighted magnetic resonance (MR) images using two radiomics approaches with machine learning models: texture analysis and topological data analysis using persistent homology. This study assessed non-contrast-enhanced fat-suppressed three-dimensional (3D) T1-weighted images of 150 hepatic tumors. The lesions included 50 hepatocellular carcinomas (HCCs), 50 metastatic tumors (MTs), and 50 hepatic hemangiomas (HHs) found respectively in 37, 23, and 33 patients. For classification, texture features were calculated, and also persistence images of three types (degree 0, degree 1 and degree 2) were obtained for each lesion from the 3D MR imaging data. We used three classification models. In the classification of HCC and MT (resp. HCC and HH, HH and MT), we obtained accuracy of 92% (resp. 90%, 73%) by texture analysis, and the highest accuracy of 85% (resp. 84%, 74%) when degree 1 (resp. degree 1, degree 2) persistence images were used. Our methods using texture analysis or topological data analysis allow for classification of the three hepatic tumors with considerable accuracy, and thus might be useful when applied for computer-aided diagnosis with MR images.

Efficacy of Automated Supplying Artery Tracking Software Using Multidetector-Row Computed Tomography Images for Emergent Transcatheter Arterial Embolization.

PURPOSE: To assess the reliability of a prototype automated supplying artery tracking software (ASATS) using multidetector-row CT (MDCT) images in emergent TAE. MATERIALS AND METHODS: Consecutive 53 patients underwent 57 sessions of emergent TAE during 7 months. Twenty-one cases were excluded due to a lack of CT data (n = 12) or negative angiographic findings (n = 9). Remaining 34 sessions of TAE and MDCT images in 32 patients (mean age 62.9 years; age range 37-92 years) were enrolled. ASATS was retrospectively conducted for the identification of supplying arteries which were confirmed with angiography (automated method). Manual modification was added as needed (semi-automated method). Two observers independently reviewed the MDCT images to detect supplying arteries (manual method). Detectability of supplying artery and time to analysis were compared among the automated, semi-automated, and manual methods by both observers. RESULTS: A total of 64 bleeding sites were demonstrated on angiography. The detectability was 28 (43.8%) for automated method, 53 (82.8%) for semi-automated method, 55 (85.9%) for observer 1, and 58 (90.6%) for observer 2. Detectability of semi-automated method was significantly better than of automated method (P = 0.000) and comparable with manual method by both observers (P = 0.193 and 0.081). Average time to analysis was 185.4 s for automated method, 297.2 s for semi-automated method, 186.2 s for observer 1, and 243.7 s for observer 2. CONCLUSION: ASATS has a sufficient ability to identify supplying arteries of bleeding by adding manual modification as needed and can be used for emergent TAE. LEVEL OF EVIDENCE: Level 4, Case Control Study.

Embolization of the Thoracic Duct by Direct Injection of N-Butyl-2-Cyanoacrylate Glue via a Puncture Needle.

PURPOSE: To report embolization of the thoracic duct by direct injection of N-butyl-2-cyanoacrylate (NBCA) glue via a puncture needle. MATERIALS AND METHODS: Two cases of high output chylothorax were successfully treated with direct injection of N-butyl-2-cyanoacrylate (NBCA) glue via a puncture needle. In them, conventional thoracic duct embolization (TDE) was attempted, but the cisterna chyli was absent on intranodal lymphangiography, and probably for this reason catheterization of the thoracic duct was unsuccessful. Contrast material injection via a puncture needle, however, clearly showed a leak from the thoracic duct, prompting us to attempt embolization of the thoracic duct by direct injection of NBCA glue via the needle. RESULTS: Thoracic duct embolization by direct injection of NBCA glue via a puncture needle was technically successful in both patients. No minor or major complication occurred. Both patients disappeared chylothorax after this treatment. CONCLUSION: This embolization method can be useful for treatment of chylothorax when conventional TDE is not achievable.

Symptomatic calcification of the lateral collateral ligament: a case report.

Symptomatic calcification is an entity in which hydroxyapatite calcific deposits cause inflammation, then burst and dissolve into the surrounding structures. Although a well-known pathologic condition in the rotator cuff tendons, it can also occur in other structures of the locomotor system. Radiographs are usually taken at the initial examination but can also be useful for follow-up evaluation of the course of the calcified matter. Here, we present a case of symptomatic calcification of the lateral collateral ligament of the knee, in which movement of the calcified matter could be observed both by radiography and magnetic resonance imaging as correlated with the clinical symptoms.

Fast skin dose estimation system for interventional radiology.

To minimise the radiation dermatitis related to interventional radiology (IR), rapid and accurate dose estimation has been sought for all procedures. We propose a technique for estimating the patient skin dose rapidly and accurately using Monte Carlo (MC) simulation with a graphical processing unit (GPU, GTX 1080; Nvidia Corp.). The skin dose distribution is simulated based on an individual patient's computed tomography (CT) dataset for fluoroscopic conditions after the CT dataset has been segmented into air, water and bone based on pixel values. The skin is assumed to be one layer at the outer surface of the body. Fluoroscopic conditions are obtained from a log file of a fluoroscopic examination. Estimating the absorbed skin dose distribution requires calibration of the dose simulated by our system. For this purpose, a linear function was used to approximate the relation between the simulated dose and the measured dose using radiophotoluminescence (RPL) glass dosimeters in a water-equivalent phantom. Differences of maximum skin dose between our system and the Particle and Heavy Ion Transport code System (PHITS) were as high as 6.1%. The relative statistical error (2 σ) for the simulated dose obtained using our system was ≤3.5%. Using a GPU, the simulation on the chest CT dataset aiming at the heart was within 3.49 s on average: the GPU is 122 times faster than a CPU (Core i7-7700K; Intel Corp.). Our system (using the GPU, the log file, and the CT dataset) estimated the skin dose more rapidly and more accurately than conventional methods.

Distribution and chemical forms of gadolinium in the brain: a review.

In the 3 years since residual gadolinium-based contrast agent (GBCA) in the brain was first reported, much has been learned about its accumulation, including the pathway of GBCA entry into the brain, the brain distribution of GBCA and its excretion. Here we review recent progress in understanding the routes of gadolinium deposition in brain structures.

Examination of the predictive factors of the response to whole brain radiotherapy for brain metastases from lung cancer using MRI.

Previous studies have been conducted on the prognostic factors for overall survival in patients with brain metastases (BMs) following whole brain radiotherapy (WBRT). However, there have been a small number of studies regarding the prognostic factors for the response of tumor to WBRT. The aim of the present study was to identify the predictive factors for the response to WBRT from the point of view of reduction of tumor using magnetic resonance imaging. A retrospective analysis of 62 patients with BMs from primary lung cancer treated with WBRT was undertaken. The effects of the following factors on the response to WBRT were evaluated: Age; sex; performance status; lactate dehydrogenase; pathology; existence of extracranial metastases; activity of extracranial disease; chemo-history; chest radiotherapy history; treatment term; γ-knife radiotherapy; diffusion weighted image signal intensity; tumor diameter; extent of edema and the edema/tumor (E/T) ratio. The association between the reduction of tumors and clinical factors was evaluated using logistic regression analysis. P<0.05 was considered to indicate a statistically significant difference. The overall response ratio of this cohort was 54.8%. In the univariate analysis, the response of tumors was associated with the presence of small cell lung carcinoma (SCLC; P=0.0007), an E/T ratio of ≥1.5 (P=0.048), and a median tumor diameter of <20 mm (P=0.014). In the multivariate analysis, the presence of SCLC [P=0.001; odds ratio (OR), 17.152), an E/T ratio of ≥1.5 (P=0.019; OR, 9.526), and the presence of extracranial metastases (P=0.031; OR, 4.875) were revealed to be independent predictive factors for the reduction of tumor. The following 3 factors were significantly associated with the response of tumors to WBRT: The presence of SCLC; an E/T ratio of ≥1.5; and the presence of extracranial metastases. The E/T ratio is a novel index that provides a simple and easy predictive method for use in a clinical setting.

Additional value of venous phase added to aortic CT angiography in patients with aortic aneurysm.

PURPOSE: To compare diagnostic performance of unenhanced and CTA images (Image set 1) to that of combined unenhanced, CTA, and venous-phase images (Image set 2) for incidentalomas in patients with aortic aneurysm. METHODS: Preoperative CT Images of consecutive 240 patients were reviewed by two observers for incidentalomas. Diagnostic performance was assessed. RESULTS: Sensitivity was higher in Image set 2 than Image set 1 in observer 1 and overall (P=0.03 and 0.00). AUCs for both observers were higher in Image set 2 than Image set 1 (P=0.03 and 0.01). CONCLUSION: Addition of venous-phase to CTA significantly improved diagnostic performance of incidentalomas.

Transcatheter Arterial Embolization for Primary Postpartum Hemorrhage: Predictive Factors of Need for Embolic Material Conversion of Gelatin Sponge Particles to N-Butyl Cyanoacrylate.

PURPOSE: To identify predictive factors for embolic material conversion to N-butyl cyanoacrylate (NBCA) for the treatment of primary postpartum hemorrhage (PPH) after failed transcatheter arterial embolization (TAE) using gelatin sponge (GS). MATERIALS AND METHODS: Institutional review board approval was obtained. We retrospectively studied 62 consecutive women with primary PPH who underwent TAE between January 2006 and March 2015. Five of them were excluded for the following: cardiopulmonary arrest at arrival (n = 1), uterine inversion (n = 1), and hysterectomy after TAE (n = 3). Remaining 57 women (age range, 21-43 years; mean, 32.6 years) comprised study population. TAE was initially performed using GS in all cases and then converted to NBCA after two embolizations using GS with persistent hemodynamic instability or vaginal bleeding. The patients' background, uterine height, vital signs, laboratory tests, disseminated intravascular coagulation score, and details of procedure were reviewed. Univariate and multivariate analyses were performed to determine factors related to embolic material conversion. RESULTS: Technical success rate was 100%. Fourteen patients (25%) needed embolic material conversion to NBCA. Univariate analysis showed that uterine height, systolic blood pressure (sBP), and hemoglobin level were significantly related to embolic material conversion to NBCA (P = 0.029, 0.030, and 0.042). Logistic regression analysis showed that uterine height (odds ratio, 1.37; P = 0.025) and sBP (odds ratio, 0.96; P = 0.003) were associated with embolic material conversion to NBCA. CONCLUSION: Uterine height and sBP can be predictive factors for embolic material conversion to NBCA for the treatment of PPH. LEVEL OF EVIDENCE: Level 4, Case Control Study.

Gadolinium deposition in the brain.

Gadolinium is highly toxic. Gadolinium-based contrast agents (GBCAs) consist of gadolinium ions and a chelating agent that binds the gadolinium ion tightly in order not to manifest its toxicity. Knowledge regarding gadolinium deposition in patients with normal renal function has advanced dramatically. Since 2014, increasing attention has been given to residual gadolinium known to accumulate in the tissues of patients with normal renal function. High signal intensity on T1-weighted images (T1WI) in the dentate nucleus, globus pallidus, and pulvinar region of the thalamus correlate roughly with the number of previous GBCA administrations. Pathological analyses have revealed that residual gadolinium is deposited not only in these brain regions, but also in extracranial tissues such as liver, skin and bone. The risks attendant with these deposits are unknown. Common sense dictates that gadolinium deposition be kept as low as possible, and that gadolinium contrast agents be used only when absolutely necessary, with preferential use of macrocyclic chelates, which seem to be deposited at lower concentrations.