Perfusion parameters as potential imaging biomarkers for the early prediction of radiotherapy response in a rat tumor model.

Purpose: We aimed to compare various tumor-related radiologic morphometric changes and computed tomography (CT) perfusion parameters before and after treatment, and to determine the optimal imaging assessment technique for the prediction of early response in a rat tumor model treated with radiotherapy.

Methods: Among paired tumors of FN13762 murine breast cancer cells implanted bilaterally in the necks of eight Fischer rats, tumors on the right side were treated with a single 20 Gy dose of radiotherapy. Perfusion CT studies were performed on day 0 before radiotherapy, and on days 1 and 5 after radiotherapy.

Gesture-Controlled Interface for Contactless Control of Various Computer Programs with a Hooking-Based Keyboard and Mouse-Mapping Technique in the Operating Room.

We developed a contactless interface that exploits hand gestures to effectively control medical images in the operating room. We developed an in-house program called GestureHook that exploits message hooking techniques to convert gestures into specific functions. For quantitative evaluation of this program, we used gestures to control images of a dynamic biliary CT study and compared the results with those of a mouse (8.

Turbulent Kinetic Energy Measurement Using Phase Contrast MRI for Estimating the Post-Stenotic Pressure Drop: In Vitro Validation and Clinical Application.

Background: Although the measurement of turbulence kinetic energy (TKE) by using magnetic resonance imaging (MRI) has been introduced as an alternative index for quantifying energy loss through the cardiac valve, experimental verification and clinical application of this parameter are still required.

Objectives: The goal of this study is to verify MRI measurements of TKE by using a phantom stenosis with particle image velocimetry (PIV) as the reference standard. In addition, the feasibility of measuring TKE with MRI is explored.

Estimation of turbulent kinetic energy using 4D phase-contrast MRI: Effect of scan parameters and target vessel size.

Quantifying turbulence velocity fluctuation is important because it indicates the fluid energy dissipation of the blood flow, which is closely related to the pressure drop along the blood vessel. This study aims to evaluate the effects of scan parameters and the target vessel size of 4D phase-contrast (PC)-MRI on quantification of turbulent kinetic energy (TKE). Comprehensive 4D PC-MRI measurements with various velocity-encoding (VENC), echo time (TE), and voxel size values were carried out to estimate TKE distribution in stenotic flow.

Three-Dimensional Printing: Basic Principles and Applications in Medicine and Radiology.

The advent of three-dimensional printing (3DP) technology has enabled the creation of a tangible and complex 3D object that goes beyond a simple 3D-shaded visualization on a flat monitor. Since the early 2000s, 3DP machines have been used only in hard tissue applications. Recently developed multi-materials for 3DP have been used extensively for a variety of medical applications, such as personalized surgical planning and guidance, customized implants, biomedical research, and preclinical education.

Better Diagnosis of Functionally Significant Intermediate Sized Narrowings Using Intravascular Ultrasound-Minimal Lumen Area and Coronary Computed Tomographic Angiography-Based Myocardial Segmentation.

Lesion morphology poorly predicts functional significance of intermediate coronary artery stenosis. The aim of this study was to determine whether a coronary artery-based myocardial segmentation method that quantifies subtended myocardium can improve the diagnostic accuracy of intravascular ultrasound (IVUS)-derived parameters for detecting ischemia-producing lesions. Coronary computed tomography angiography, IVUS, and fractional flow reserve (FFR) data were analyzed in 101 non-left main lesions (20% to 80% angiographic stenosis).

Synergistic Effect of Anti-Angiogenic and Radiation Therapy: Quantitative Evaluation with Dynamic Contrast Enhanced MR Imaging.

Purpose: We assessed the effects of anti-angiogenic therapy (AAT) on radiation therapy (RT), evaluating the tumor growth and perfusion patterns on dynamic contrast enhanced MR (DCE-MR) images.

Methods: Thirteen nude mice with heterotopic xenograft cancer of human lung cancer cell line were used. To observe the interval change of the tumor size and demonstrate the time-signal intensity enhancement curve of the tumor, the mice were subdivided into four groups: control (n = 2), AAT (n = 2), RT (n = 5), and combined therapy (AART, n = 4).

Four-dimensional flow MRI for evaluation of post-stenotic turbulent flow in a phantom: comparison with flowmeter and computational fluid dynamics.

Objectives: To validate 4D flow MRI in a flow phantom using a flowmeter and computational fluid dynamics (CFD) as reference.

Methods: Validation of 4D flow MRI was performed using flow phantoms with 75 % and 90 % stenosis. The effect of spatial resolution on flow rate, peak velocity and flow patterns was investigated in coronal and axial scans.

Intravoxel incoherent motion MRI for monitoring the therapeutic response of hepatocellular carcinoma to sorafenib treatment in mouse xenograft tumor models.

Background With the introduction of targeted therapies, there has been a growing need for non-invasive imaging methods which accurately evaluate therapeutic effects and overcome the limitations of tumor size-based therapeutic response assessments. Purpose To assess diagnostic values of intra-voxel incoherent motion (IVIM) imaging in evaluating therapeutic effects of sorafenib on hepatocellular carcinoma (HCC) using mouse xenograft model. Material and Methods Twenty-four mice bearing Huh-7 were divided into a control group and two treatment groups received sorafenib doses of 5 mg/kg (5 mg-Tx) or 30 mg/kg (30 mg-Tx).

Post-stenotic Recirculating Flow May Cause Hemodynamic Perforator Infarction.

Background And Purpose: The primary mechanism underlying paramedian pontine infarction (PPI) is atheroma obliterating the perforators. Here, we encountered a patient with PPI in the post-stenotic area of basilar artery (BA) without a plaque, shown by high-resolution magnetic resonance imaging (HR-MRI). We performed an experiment using a 3D-printed BA model and a particle image velocimetry (PIV) to explore the hemodynamic property of the post-stenotic area and the mechanism of PPI.

Assessment of Regional Xenon Ventilation, Perfusion, and Ventilation-Perfusion Mismatch Using Dual-Energy Computed Tomography in Chronic Obstructive Pulmonary Disease Patients.

Objectives: The aim of this study was to assess the feasibility of combined xenon-enhanced ventilation (V) and iodine-enhanced perfusion (Q) dual-energy computed tomography (DECT) to evaluate regional V and Q status in patients with chronic obstructive pulmonary disease (COPD).

Materials And Methods: Combined V and Q DECT imaging was performed in 52 prospectively enrolled male COPD patients. Virtual noncontrast images, V maps, and Q maps were anatomically coregistered with deformable registration and evaluated using in-house software.

Post-stenotic plug-like jet with a vortex ring demonstrated by 4D flow MRI.

Purpose: To investigate the details of the flow structure of a plug-like jet that had a vortex ring in pulsatile stenotic phantoms using 4D flow MRI.

Method: Pulsatile Newtonian flows in two stenotic phantoms with 50% and 75% reductions in area were scanned by 4D flow MRI. Blood analog working fluid was circulated via the stenotic phantom using a pulsatile pump at a constant pulsating frequency of 1Hz.

Visual Assessment of Chest Computed Tomography Findings in Anti-cyclic Citrullinated Peptide Antibody Positive Rheumatoid Arthritis: Is it Associated with Airway Abnormalities?

Introduction: We aimed to evaluate the association between specific anti-cyclic citrullinated peptide antibody (ACCPA) and pulmonary abnormalities in rheumatoid arthritis (RA) subjects.

Methods: Computed tomography (CT) images of 83 subjects with RA were evaluated in a blind fashion. Enrolled subjects underwent autoantibody testing to determinate titer of ACCPA and rheumatoid factor, and pulmonary function testing.

Lesion Location-Based Prediction of Visual Field Improvement after Cerebral Infarction.

Background: Although the prognosis of ischemic stroke is highly dependent on the lesion location, it has rarely been quantitatively utilized. We investigated the usefulness of regional extent of ischemic lesion (rEIL) predicting the improvement of visual field defect (VFD) in patients with posterior cerebral artery infarction.

Methods: The rEILs were measured in each individual cortex after transforming the lesions to a standard atlas.

Optimal threshold of subtraction method for quantification of air-trapping on coregistered CT in COPD patients.

Objectives: To investigate the optimal threshold of subtraction method for quantification of air trapping on co-registered CT in COPD patients in correlation with pulmonary function parameters.

Methods: From June 2005 to October 2010, 174 patients were included in our study. Inspiration and expiration CT were performed followed by non-rigid registration using in-house software.

Perfusion- and pattern-based quantitative CT indexes using contrast-enhanced dual-energy computed tomography in diffuse interstitial lung disease: relationships with physiologic impairment and prediction of prognosis.

Objectives: To evaluate automated texture-based segmentation of dual-energy CT (DECT) images in diffuse interstitial lung disease (DILD) patients and prognostic stratification by overlapping morphologic and perfusion information of total lung.

Methods: Suspected DILD patients scheduled for surgical biopsy were prospectively included. Texture patterns included ground-glass opacity (GGO), reticulation and consolidation.

Bronchoscopic lung volume reduction by endobronchial valve in advanced emphysema: the first Asian report.

Purpose: Endobronchial valve (EBV) therapy is increasingly being seen as a therapeutic option for advanced emphysema, but its clinical utility in Asian populations, who may have different phenotypes to other ethnic populations, has not been assessed.

Patients And Methods: This prospective open-label single-arm clinical trial examined the clinical efficacy and the safety of EBV in 43 consecutive patients (mean age 68.4±7.

Erratum: Clinical Application of Three-Dimensional Printing Technology in Craniofacial Plastic Surgery.

[This corrects the article on p. 267 in vol. 42, PMID: 26015880.

Histogram Analysis of Apparent Diffusion Coefficients for Occult Tonsil Cancer in Patients with Cervical Nodal Metastasis from an Unknown Primary Site at Presentation.

Purpose: To explore the added value of histogram analysis of apparent diffusion coefficient (ADC) values over magnetic resonance (MR) imaging and fluorine 18 ((18)F) fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) for the detection of occult palatine tonsil squamous cell carcinoma (SCC) in patients with cervical nodal metastasis from a cancer of an unknown primary site.

Materials And Methods: The institutional review board approved this retrospective study, and the requirement for informed consent was waived. Differences in the bimodal histogram parameters of the ADC values were assessed among occult palatine tonsil SCC (n = 19), overt palatine tonsil SCC (n = 20), and normal palatine tonsils (n = 20).

Multi-VENC acquisition of four-dimensional phase-contrast MRI to improve precision of velocity field measurement.

Purpose: The present study aims to improve precision of four-dimensional (4D) phase-contrast (PC) MRI technique by using multiple velocity encoding (VENC) parameters.

Theory And Methods: The 3D flow fields in an in vitro stenosis phantom and an in vivo ascending aorta were determined using a 4D PC-MRI sequence with multiple VENC values. The velocity field obtained for large VENC was combined with that from small VENC, unless velocity data were lost by phase aliasing and phase dispersion.

Clinical application of three-dimensional printing technology in craniofacial plastic surgery.

Three-dimensional (3D) printing has been particularly widely adopted in medical fields. Application of the 3D printing technique has even been extended to bio-cell printing for 3D tissue/organ development, the creation of scaffolds for tissue engineering, and actual clinical application for various medical parts. Of various medical fields, craniofacial plastic surgery is one of areas that pioneered the use of the 3D printing concept.

Subprosthetic Pannus after Aortic Valve Replacement Surgery: Cardiac CT Findings and Clinical Features.

Purpose: To investigate the cardiac computed tomographic (CT) findings and clinical implications of subprosthetic pannus in patients who have undergone aortic valve replacement.

Materials And Methods: The institutional review board approved this retrospective study, and the need to obtain written informed consent was waived. From April 2011 to March 2012, 88 patients (mean age, 63 years; 45 men) with a prosthetic aortic valve who underwent cardiac CT were retrospectively selected.