Reliability of respiratory-gated real-time two-dimensional cine incorporating deep learning reconstruction for the assessment of ventricular function in an adult population.

This study aimed to assess the image quality and accuracy of respiratory-gated real-time two-dimensional (2D) cine incorporating deep learning reconstruction (DLR) for the quantification of biventricular volumes and function compared with those of the standard reference, that is, breath-hold 2D balanced steady-state free precession (bSSFP) cine, in an adult population. Twenty-four patients (15 men, mean age 50.7 ± 16.

Friction Dynamics of Foaming Body Cleansers under Sinusoidal Motion.

The friction characteristics of foaming body cleansers determine skin physical irritation, as well as the usability of the products. In this study, the friction of foam formed by a commercial body cleanser was evaluated using a sinusoidal-motion friction evaluation system. The friction profile of the foam was a hydrodynamic stable pattern, where the friction force increased with increasing velocity.

Dedicated phantom tools using traceable Ge/Ga point-like sources for dedicated-breast PET and positron emission mammography scanners.

Since the early 2000s, many types of positron emission tomography (PET) scanners dedicated to breast imaging for the diagnosis of breast cancer have been introduced. However, conventional performance evaluation methods developed for whole-body PET scanners cannot be used for such devices. In this study, we developed phantom tools for evaluating the quantitative accuracy of positron emission mammography (PEM) and dedicated-breast PET (dbPET) scanners using novel traceable point-like Ge/ Ga sources.

Friction Dynamics of Foams under Nonlinear Motion.

Foams are viscoelastic soft materials with complex mechanical properties. Here, we evaluated the friction dynamics of foams between acrylic plates using a sinusoidal motion friction evaluation system and we found some interesting characteristics under accelerated conditions. On a typical solid surface, a symmetrical friction profile, in which static and kinetic frictions are observed, is obtained under reciprocating nonlinear motion.

and Partially Suppress G1 Phase Arrest Caused by Spliceostatin A Treatment.

The potent splicing inhibitor spliceostatin A (SSA) inhibits cell cycle progression at the G1 and G2/M phases. We previously reported that upregulation of the p27 cyclin-dependent kinase inhibitor encoded by and its C-terminal truncated form, namely p27*, which is translated from pre-mRNA, is one of the causes of G1 phase arrest caused by SSA treatment. However, the detailed molecular mechanism underlying G1 phase arrest caused by SSA treatment remains to be elucidated.

Nonlinear Friction Dynamics of Oil-in-Water and Water-in-Oil Emulsions on Hydrogel Surfaces.

In this study, the friction properties of emulsions in an oral environment were investigated to understand the food-texture recognition mechanisms occurring on biological surfaces. Numerous publications have suggested that the friction phenomena depend on friction conditions, such as the surface characteristics, as well as the shape and movement of contact probes. Traditional friction evaluation systems are unsuitable for mimicking the oral environment.

Friction Dynamics of Hydrogel Substrates with a Fractal Surface: Effects of Thickness.

Interfacial phenomena on soft and wet materials, such as hydrogels, are important for modeling physical phenomena, such as friction, wetting, and adhesion on hydrophilic biosurfaces. Interfacial phenomena on soft material surfaces are not only affected by the properties of the surface but also by the geometry of the substrate. However, there are few reports on the influence of geometry and deformability on friction behavior at gel interfaces.

Traceable point-like Ge/Ga source with a spherically symmetric positron absorber for PET scanners.

A novel traceable point-like Ge/Ga source was developed for calibration of positron emission tomography (PET) scanners. The source was equipped with a spherically symmetric acrylic positron absorber. The physical characteristics of photons emitted from the point-like source were evaluated by Monte Carlo simulation, considering possible geometrical uncertainties.

Utility of an adverse drug event database based on the narrative accounts of patients with breast cancer.

Patient narratives of adverse drug events (ADEs) often differ from the symptoms listed on the package inserts of pharmaceutical products using common ADE terminology and could be a source of great comfort to patients with the same disease. To explore this idea, we analyzed written narratives obtained from 48 patients with breast cancer using the NPO Corporation Database of Individual Patients' Experiences, Japan (DIPEx-Japan). Our analysis aimed to determine the utility of an "Adverse Drug Event Database" for use in clinical settings as a novel source of disease information in patients' own words.

[Development of Body Phantom for Evaluation of Appropriate Administered Radioactivities and Image Quality on Tc-DMSA Scintigraphy in Pediatric Nuclear Medicine].

Purpose: We conducted a field survey about pediatric nuclear medicine. As a result, it was suggested that Tc-DMSA scintigraphy was performed at many institutions, whereas various examinations such as image acquisition and processing are not carried out using the renal phantom. Therefore, we developed the body phantom for the evaluation of appropriate administered radioactivities and image quality with renal scintigraphy in pediatric nuclear medicine.

Ultra-high-resolution CT angiography of the artery of Adamkiewicz: a feasibility study.

Purpose: Preoperative identification of the artery of Adamkiewicz can help prevent postoperative spinal cord injury following thoracic and thoracoabdominal aortic repair. Several studies have demonstrated the feasibility of evaluating the artery of Adamkiewicz using multi-detector row computed tomography (CT), but precise visualization remains a challenge. The present study was conducted to evaluate the usefulness of ultra-high-resolution CT for visualizing the artery of Adamkiewicz with a slice thickness of 0.

[Effects of Different Containers on Radioactivity Measurements using a Dose Calibrator with Special Reference to In and I].

Low-energy characteristic x-rays emitted by In and I sources are easily absorbed by the containers of the sources, affecting radioactivity measurements using a dose calibrator. We examined the effects of different containers on the estimated activities. The radioactivities of In, I, Tl, and Tc were measured in containers frequently employed in clinical practice in Japan.

[Examination of a Method to Determine the Reference Region for Calculating the Specific Binding Ratio in Dopamine Transporter Imaging].

The specific binding ratio (SBR) was first reported by Tossici-Bolt et al. for quantitative indicators for dopamine transporter (DAT) imaging. It is defined as the ratio of the specific binding concentration of the striatum to the non-specific binding concentration of the whole brain other than the striatum.

Diagnostic accuracy of a modified subtraction coronary CT angiography method with short breath-holding time: a feasibility study.

Objective: To explore the feasibility and diagnostic accuracy of modified subtraction coronary CT angiography (CCTA) with short breath-holding time in patients who have limited breath-hold capability and severe coronary artery calcification.

Methods: 11 patients with a coronary calcium score >400 underwent CCTA using a modified subtraction protocol. All patients were unable to hold their breath for more than 20 s.

Modified Subtraction Coronary CT Angiography Method for Patients Unable to Perform Long Breath-Holds: A Preliminary Study.

Rationale And Objectives: Severe calcifications of the coronary arteries are still a major challenge in coronary computed tomography (CT) angiography (CCTA). Subtraction CCTA using a 320-detector row CT scanner has recently been introduced for patients with severe calcifications. However, the conventional subtraction CCTA method requires a long breath-holding time of approximately 20-40 seconds.

Correction of collimator-dependent differences in the heart-to-mediastinum ratio in I-metaiodobenzylguanidine cardiac sympathetic imaging: Determination of conversion equations using point-source imaging.

Background: Septal penetration causes collimator-dependent differences in the heart-to-mediastinum (H/M) ratio in I-metaiodobenzylguanidine (MIBG) cardiac imaging. We investigated generally applicable methods to correct such differences.

Methods And Results: Four hours after I-MIBG injection, 40 patients underwent anterior chest imaging successively with medium-energy (ME) and various non-ME collimators.

Report of a nationwide survey on actual administered radioactivities of radiopharmaceuticals for diagnostic reference levels in Japan.

Objective: The optimization of medical exposure is one of the major issues regarding radiation protection in the world, and The International Committee of Radiological Protection and the International Atomic Energy Agency recommend establishing diagnostic reference levels (DRLs) as tools for dose optimization. Therefore, the development of DRLs based on the latest survey has been required for nuclear medicine-related societies and organizations. This prompted us to conduct a nationwide survey on the actual administered radioactivity to adults for the purpose of developing DRLs in nuclear medicine.

Validity of the mediastinum as a reference region to evaluate cardiac accumulation of iodine-123 metaiodobenzylguanidine.

Objective: The heart-to-mediastinum (H/M) ratio, the heart count normalized for the mediastinum count, is commonly used in cardiac (123)I-metaiodobenzylguanidine (MIBG) imaging. However, there are reports describing age-dependent increases in the mediastinum count with or without correction for the injected dose (ID) and a poor correlation between the H/M ratio and heart count normalized for ID. We evaluated the validity of the mediastinum count as a reference in comparison with the ID.

Impact of injected dose and acquisition time on a normal database by use of 3D-SSP in SPECT images: quantitative simulation studies.

The present study aimed to validate the accuracy of normal databases (NDBs) with respect to variable injected doses and acquisition times by use of three-dimensional stereotactic surface projections (3D-SSP) in N-isopropyl-p-[123I]-iodoamphetamine (I-123-IMP) brain perfusion images. We constructed NDBs based on brain SPECT images obtained from 29 healthy volunteers. Each NDB was rebuilt under simulated unique conditions by use of dynamic acquisition datasets and comprised injected doses (222, 167, and 111 MBq) and acquisition times (30, 20, and 15 min).

Phase IIa Clinical Trial of Trans-1-Amino-3-(18)F-Fluoro-Cyclobutane Carboxylic Acid in Metastatic Prostate Cancer.

Objectives: We performed a phase IIa clinical trial of trans-1-amino-3-(18)F-fluoro-cyclobutane carboxylic acid (anti-(18)F-FACBC), a synthetic amino acid analog for PET, in patients with metastatic prostate cancer.

Methods: The study subjects consisted of 10 untreated prostate cancer patients having lymph node and/or bone metastasis. Five patients underwent whole-body PET 5 and 30 min after intravenous injection of anti-(18)F-FACBC.

An improved method for estimating the heart-to-mediastinum ratio from cardiac sympathetic nerve imaging with low-energy high-resolution collimators.

Background: Septal penetration causes underestimation of the heart-to-mediastinum (H/M) ratio in cardiac (123)I-metaiodobenzylguanidine (MIBG) imaging with a low-energy high-resolution (LEHR) collimator. We aimed to improve the method of estimating the H/M ratios using the LEHR collimator.

Methods And Results: 4 hours after (123)I-MIBG injection, 40 patients were imaged successively with the medium-energy (ME) and LEHR collimators using gamma cameras having 3/8-inch crystals.

Septal penetration in iodine-123 metaiodobenzylguanidine cardiac sympathetic imaging using a medium-energy collimator.

Background: Septal penetration of high-energy photons affects the estimation of the heart-to-mediastinum (H/M) ratio in cardiac (123)I-metaiodobenzylguanidine (MIBG) imaging, and the use of a medium-energy (ME) collimator has been shown to improve quantitative accuracy. We investigated the effect of septal penetration on the estimation of H/M ratios using an ME collimator.

Methods And Results: Point sources of (99m)Tc and (123)I were imaged using various collimators, which indicated that the effect of high-energy photons with the ME collimator was relatively small but larger than that with the high-energy (HE) collimator.

Acquisition protocols and correction methods for estimation of the heart-to-mediastinum ratio in 123I-metaiodobenzylguanidine cardiac sympathetic imaging.

Unlabelled: Septal penetration of high-energy photons affects quantitative results in imaging of (123)I-labeled tracers. We investigated acquisition protocols (collimator choice and energy window setting) and correction methods for estimating the heart-to-mediastinum (H/M) ratio in cardiac (123)I-metaiodobenzylguanidine (MIBG) imaging.

Methods: Four hours after (123)I-MIBG injection, 40 patients successively underwent planar anterior chest imaging with the medium-energy (ME) (ME method) and low-energy high-resolution (LEHR) (LEHR method) collimators.

[Availability of normal database by single photon emission computed tomography system with use of 3 dimensional-stereotactic surface projections].

Purpose: The present study aims to quantitatively investigate a normal database (NDB) created under the same acquisition and reconstruction conditions for three gamma camera systems (four types of collimator systems) with use of three-dimensional stereotactic surface projections (3D-SSP). We rebuilt a NDB with use of the N-isopropyl-p-(123)I-iodoamphetamine ((123)I-IMP) SPECT data derived from 30 healthy individuals at 20 institutions nationwide. We standardized the acquisition and reconstruction conditions, evaluated Z scores using patient data (PD) and examined each compensation effect.