Hiromasa Imaizumi

Kawasaki Unviersity of Medical Welfare · Depatment of Radiological Technology

To predict endoleaks after thoracic endovascular aneurysm repair (TEVAR) we submitted patient characteristics and vessel features observed on pre- operative computed tomography angiography (CTA) to machine-learning. We evaluated 1-year follow-up CT scans (arterial and delayed phases) in patients who underwent TEVAR for the presence or absence of an...

Objectives This study assessed whether patient-specific contrast enhancement optimizer simulation software (p-COP) can reduce the contrast material (CM) dose compared with the conventional body weight (BW)-tailored scan protocol during transcatheter aortic valve implantation-computed tomography angiography (TAVI-CTA) in patients with aortic stenosi...

Cell motility is related to the higher-order structure of chromatin. Stimuli that induce cell migration change chromatin organization; such stimuli include elevated histone H3 lysine 9 trimethylation (H3K9me3). We previously showed that depletion of histone H3 lysine 9 methyltransferase, SUV39H1, suppresses directional cell migration. However, the...

We investigated the effect of electrocardiographic (ECG) mA-modulation of ECG-gated scans of computed tomography (CTA) on radiation dose and image noise at high heart rates (HR) above 100 bpm between helical pitches (HP) 0.16 and 0.24. ECG mA-modulation range during ECG-gated CTA is 50-100 mA, the phase setting is 40-60% and the scan range is 90 mm...

To evaluate the effects of various patient characteristics on vessel enhancement on arterio-venous fistula (AVF) computed tomography (CT) angiography (AVF-CT angiography). A total of 127 patients with suspected or confirmed shunt stenosis and internal AVF complications were considered for inclusion in a retrospective cohort study. The tube voltage...

Purpose: To predict endoleaks after thoracic endovascular aneurysm repair (TEVAR) we submitted patient characteristics and vessel features observed on pre- operative computed tomography angiography (CTA) to machine-learning. Methods: We evaluated 1-year follow-up CT scans (arterial and delayed phases) in patients who underwent TEVAR for the prese...

Cell motility is related to the higher-order structure of chromatin. Stimuli that induce cell migration change chromatin organization; such stimuli include elevated histone H3 lysine 9 trimethylation (H3K9me3). We previously showed that depletion of histone H3 lysine 9 methyltransferase, SUV39H1, suppresses directional cell migration. However, the...

Purpose: This study assessed whether patient-specific contrast enhancement optimizer simulation software (p-COP) can reduce the contrast material (CM) dose compared with the conventional body weight (BW)-tailored scan protocol during transcatheter aortic valve implantation-computed tomography angiography (TAVI-CTA) in patients with aortic stenosis....

To compare the radiation dose and diagnostic ability of the 100-kVp protocol, based on the contrast noise ratio (CNR) index, during coronary artery bypass graft (CABG) vessels with those of the 120-kVp protocol. For the 120-kVp scans (150 patients), the targeted image level was set at 25 Hounsfield units (HU) (CNR120 = iodine contrast/25 HU). For t...

The linker of nucleoskeleton and cytoskeleton (LINC) complex has been implicated in various functions of the nuclear envelope, including nuclear migration, mechanotransduction and DNA repair. We previously revealed that the LINC complex component Sad1 and UNC84 domain containing 1 (SUN1) is required for sublethal-dose X-ray-enhanced cell migration...

Background: To compare the effect of obtaining the anteroposterior scout view (APSV) with that of posteroanterior scout view (PASV) on mammary gland dose in pediatric patients. Methods: We used a pediatric anthropomorphic phantom with a 64 detector-row computed tomography (CT) scanner using the APSV or PASV protocol of the chest. A real-time skin d...

Background: This study aims to investigate the suitability of the air gap method for radiation dose reduction in pediatric patients during computed tomography (CT) examinations. Methods: We use pediatric anthropomorphic phantoms with a 64 detector-row CT scanner while scanning the chest. A real-time skin dosimeter is placed on the scanner gantry an...

Introduction: This study aims to predict endoleak after endovascular aneurysm repair (EVAR) using machine learning (ML) integration of patient characteristics, stent-graft configuration, and a selection of vessel lengths, diameters and angles measured using pre-operative computed tomography angiography (CTA). Methods: We evaluated 1-year follow-...

Introduction The purpose of this study was to demonstrate that dose reduction does not compromise image quality when combining high helical pitch (HP) and the ECG-Edit function during low HP retrospectively gated computed tomography angiography (CTA). Methods This study made use of a pulsating cardiac phantom (ALPHA 1 VTPC). The heart rate (HR) of...

To evaluate whether the patient-specific contrast enhancement optimizer simulation software (p-COP) is useful for predicting contrast enhancement during whole-body computed tomography angiography (WBCTA). We randomly divided the patients into two groups using a random number table. We used the contrast material (CM) injection protocol selected by p...

Introduction To investigate how changing the injection duration at cardiac computed tomography angiography (CCTA) affects contrast enhancement in newborns and infants. Methods Included were 142 newborns and infants with confirmed congenital heart disease who underwent CCTA between January 2015 and December 2018. In group 1 (n = 71 patients), the i...

Introduction To compare the computed tomography (CT) number for paediatric cardiac computed tomography angiography (CCTA) and visualisation score of the three-dimensional (3D) images using the conventional T-shaped extended tube (T-tube) and spiral flow-generating extended tube (spiral-tube) connected between the contrast injector and cannula. Met...

Introduction This study aimed to compare the correlation between the computed tomography (CT) enhancement rate of the venous to portal venous phase (VP-ER) and the extracellular volume (ECV) fraction with shear-wave ultrasound elastography (USE) findings in patients with liver fibrosis. Methods We included 450 patients with clinically suspected li...

Flattening filter-free (FFF) photon beams minimize the intrafraction motion of tumors, and this feature is useful in pulmonary malignancies, such as non-small-cell lung cancer (NSCLC). However, the radiobiological effects of such beams on NSCLC cells, which are often treated with stereotactic body radiotherapy (SBRT), have not been investigated suf...

The linker of nucleoskeleton and cytoskeleton (LINC) complex is a multifunctional protein complex that is involved in various process at the nuclear envelope including nuclear migration, mechanotransduction, chromatin tethering, and DNA damage response. We recently showed that a nuclear envelope protein, Sad1 and UNC84 domain protein 1 (SUN1); a co...

Induced pluripotent stem (iPS) cells have demonstrated they can undergo self-renewal, attain pluripotency, and differentiate into various types of functional cells. In clinical transplantation of iPS cells, however, a major problem is the prevention of tumorigenesis. We speculated that tumor formation could be inhibited by means of irradiation. Sin...

The LINC complex is a multifunctional protein complex that is involved in various processes at the nuclear envelope, such as nuclear migration, mechanotransduction and chromatin tethering in the meiotic phase. However, it remains unknown how these functions are regulated in different cell contexts. An inner nuclear membrane component of the LINC co...

Glioblastoma is one of the most fatal malignant tumors because of its invasiveness and radioresistance. Unfortunately photon irradiation and hypoxic condition are reported to enhance cancer cells' aggressiveness respectively. The purpose of this study is to clarify the effect of carbon ion beam on invasive potential of glioblastoma cells. Relative...